Fastener string cutting device

Abstract

To provide a fastener string cutting device that can cut fastener strings wound around fastened objects efficiently and smoothly even on a surface part inclined from a surface perpendicular to the forward and backward direction.SOLUTION: A fastener string cutting device is configured to include a cutting part 20 equipped with a linear cutting tool 21, a follower mechanism 12 with a pair of slide support parts 12a, and a connecting part 13 that connects the cutting part 20 to a base board part 11. The connecting part 13 has an upper rod-shaped member 14 and a lower oscillating rod-shaped member 15. The upper rod-shaped member 14 is attached to the base board part 11, and the lower end part of the upper rod-shaped member 14 and the upper end part of the lower oscillating rod-shaped member 15 are rotatably connected around a hinge pin 22c that has a rotation axis perpendicular to an extending direction Y of the linear cutting tool 21. The pair of slide support parts 12a of the follower mechanism 12 have their lower ends disposed flush with the lower edge part of the linear cutting tool 21.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a fastening cord cutting device and a fastening cord cutting method for cutting a fastening cord that fastens a hexahedral object. [Background technology]

[0002] 2. Description of the Related Art In factories and the like, cardboard material that has been folded into a rectangular flat plate shape is unfolded into a hollow box, i.e., a cardboard box is formed, and products are packed inside the box. The folded cardboard material is brought in in a hexahedral shape with multiple sheets stacked one on top of the other, and then each sheet is removed and unfolded into a hollow box, with products packed inside.

[0003] Such multiple cardboard sheets stacked in a hexahedral shape are brought into a factory or the like in a bundled state with a fastening string wrapped around them as objects to be fastened with the fastening string. For example, in a boxing system installed in a factory or the like, it is necessary to remove the fastening string so that the cardboard sheets can be taken out one by one, and various fastening string cutting devices and cutting mechanisms have been proposed (for example, see Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-95138 Summary of the Invention [Problem to be solved by the invention]

[0005] However, conventional cutting devices and mechanisms for cutting a fastening string fastening a hexahedral object, such as a stack of multiple cardboard sheets, have a complex configuration and require complex control of the movement of the cutting part. Therefore, there is a need for a technology that can cut a fastening string wrapped around an object, preferably with a simple configuration and control that simply involves moving the cutting part forward and backward using a robot arm or end effector.

[0006] A part of the fastening string crosses the upper surface of the hexahedral fastened object, and this upper surface may be inclined or distorted, and may not be parallel to the surface of the cutting part where the cutting tool is provided. Even in such an inclined or distorted upper surface, it is necessary to devise a method for cutting the fastening string by arranging the cutting tool provided in the cutting part along the upper surface of the fastened object with a simple configuration and control that simply moves the cutting part forward and backward.

[0007] The present invention relates to a fastening cord cutting device and a fastening cord cutting method that can cut a fastening cord even on a surface that is tilted or distorted and not parallel to the surface on which the cutting tool of the cutting part is provided, by using a simple configuration and control that simply involves moving the cutting part forward and backward. [Means for solving the problem]

[0008] The present invention is a fastening cord cutting device that cuts a fastening cord wound around a hexahedral fastened object at a surface portion across which the fastening cord crosses, and is configured to include a base plate portion to which an advancing / retreating mechanism that moves the cutting device back and forth toward the surface portion across which the fastening cord crosses the object is connected, a cutting section equipped with a linear cutting tool that is arranged to cross the fastening cord and to be in contact with or close to the fastening cord to cut the fastening cord, a follow-up mechanism having a pair of slide support parts that are arranged to sandwich the cutting section in the extension direction of the linear cutting tool, and a connecting part that connects the cutting section to the base plate portion. The connection portion has an upper rod-shaped member extending perpendicular to the base plate portion, a lower oscillating rod-shaped member, and a connection base portion to which the cutting portion is attached, and the upper rod-shaped member is attached to the base plate portion, and the lower end of the upper rod-shaped member and the upper end of the lower oscillating rod-shaped member are rotatably connected around a rotation axis perpendicular to the extension direction of the linear cutting tool, and the lower end of the lower oscillating rod-shaped member is connected to the connection base portion, and the pair of slide support portions of the following mechanism are supported by the connection base portion, and their lower ends are positioned flush or approximately flush with the lower edge portion of the linear cutting tool.

[0009] The present invention also provides a method for cutting a fastening cord using the above-mentioned fastening cord cutting device, the method comprising the steps of: moving the fastening cord cutting device to a portion of a surface portion of the hexahedral object across which the wrapped fastening cord crosses, the portion facing the fastening cord; advancing the fastening cord cutting device by the advancing / retracting mechanism until the pair of slide support parts abut against the surface portions of the object across which the fastening cord crosses, thereby positioning the linear cutter so as to come into contact with or be close to the fastening cord; and cutting the fastening cord with the positioned linear cutter, In the process, when the surface of the object to be fastened that is crossed by the fastening string is not parallel to the base plate portion, the advancement and retreat mechanism advances to abut one of the slide support parts against the surface of the object to be fastened that is crossed by the fastening string, and then the lower oscillating rod-shaped member is swung relative to the upper rod-shaped member and the one slide support part is slid along the surface of the object to be fastened that is crossed by the fastening string, thereby abutting the other slide support part against the surface of the object to be fastened that is crossed by the fastening string, and the linear cutting tool is positioned along the surface of the object to be fastened that is crossed by the fastening string. Effect of the Invention

[0010] According to the fastening cord cutting device or fastening cord cutting method of the present invention, by simply moving the cutting section forward and backward, the fastening cord can be cut even on a surface that is tilted or distorted and is not parallel to the surface on which the cutting tool of the cutting section is provided. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a perspective view of a fastening cord cutting device according to a preferred embodiment of the present invention, as viewed obliquely from the front. [Diagram 2] FIG. 2 is a perspective view of a fastening cord cutting device according to a preferred embodiment of the present invention, as viewed obliquely from behind. [Diagram 3] FIG. 3 is a perspective view seen obliquely from the front, illustrating the main parts of the fastening cord cutting device, excluding the air ejection mechanism and the heating mechanism of the linear cutter. [Figure 4] FIG. 4 is a front view illustrating the main parts of the fastening cord cutting device, excluding the air ejection mechanism and the heating mechanism for the linear cutter. [Diagram 5] 5(a) and (b) are explanatory diagrams showing a state in which the linear cutting tool is arranged along a surface portion of the object to be fastened, across which the fastening string crosses. [Figure 6] 6(a) to (c) are explanatory diagrams showing a state in which the fastening cord is cut by the linear cutter. [Figure 7] FIG. 7 is a front view of the fastening cord cutting device illustrating a switching means for switching the lower swingable rod member to a fixed state in which the lower swingable rod member does not swing relative to the upper rod member. [Figure 8] 8(a) and (b) are schematic cross-sectional views illustrating a state in which the cut end of the fastening string is blown off by an air nozzle member. [Figure 9] FIG. 9 is a schematic cross-sectional view illustrating a state in which the other cut end of the cut fastening cord is sucked in by a cut cord suction device. [Figure 10] Figures 10(a) to (c) are simplified cross-sectional views illustrating problems that can occur when objects fastened together using fastening strings to fasten a laminate of cardboard material are stacked one on top of the other in multiple tiers, with the knots of the fastening strings getting caught on each other. [Figure 11] FIG. 11 is a schematic cross-sectional view illustrating a means for eliminating the inconvenience caused by the knots of the fastening strings getting caught on each other. [Figure 12] Figures 12(a) and (b) are explanatory diagrams of a situation in which a linear cutting tool of a fastening cord cutting device, which has only one set of an upper rod-shaped member and a lower oscillating rod-shaped member, is positioned along the surface portion across which the fastening cord of the object to be fastened crosses. [Figure 13] FIG. 13 is an explanatory diagram of each step of a fastening-cord cutting method using a fastening-cord cutting device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] 1 and 2 show a fastening cord cutting device 10 according to a preferred embodiment of the present invention. The fastening cord cutting device 10 handles a stack formed by stacking multiple sheets of cardboard material 41, which is a thin plate-like article before being assembled into a hollow three-dimensional cardboard box, folded, for example, into a rectangular flat plate shape, as a hexahedral fastened object 40 (see Figs. 5(a) and 5(b)). That is, the fastening cord cutting device 10 is used as a device for cutting a fastening cord 50 (see Figs. 5(a) and 5(b)), which is made of, for example, synthetic resin and which is wrapped around the hexahedral fastened object 40 and fastens the multiple sheets of cardboard material 41 together, at the upper surface 40a of the hexahedral fastened object 40 where the fastening cord 50 crosses (see Fig. 6(a)), so that the fastened cardboard materials 41 can be taken out one by one. The fastening cord cutting device 10 of this embodiment is attached to a robot arm 51 as an end effector for use, and the robot arm 51 is used as an advance / retract mechanism, and the cutting unit 20 equipped with the linear cutting tool 21 is advanced and moved toward the upper surface 40a of the hexahedral fastened object 40 in the vertical direction from directly above the upper surface 40a toward the upper surface 40a. With a simple configuration and control, the fastening cord cutting device 10 has a function of cutting the fastening cord 50 wound around the fastened object 40 even when the upper surface 40a of the fastened object 40 is a surface that is inclined or distorted from the surface equipped with the linear cutting tool 21 of the cutting unit 20. The surface on which the fastening cord is cut is not limited to the upper surface 40a. The advance / retract direction is not limited to the vertical direction, and may be a direction perpendicular to the surface on which the fastening cord 50 is cut (a surface other than the upper surface 40a).

[0013] The fastening cord cutting device 10 of this embodiment is a cutting device that cuts the fastening cord 50 wound around the hexahedral fastened object 40 at a surface portion (upper surface portion 40a of the fastened object 40) across which the fastening cord 50 crosses, and has a base plate portion 11 to which a robot arm 51 (see FIG. 1), which is an advancing and retreating mechanism that moves the cutting device 10 toward and away from the upper surface portion 40a of the fastened object 40, is connected, as shown in FIGS. 3 and 4. The fastening cord cutting device 10 also has a cutting unit 20 equipped with a linear cutter 21 that is arranged to cross the fastening cord 50 and to be in contact with or in close proximity to the fastening cord 50 to cut the fastening cord 50 (see FIGS. 5(a), (b), and 6(a) to (c)). The cutting device 10 also includes a follower mechanism 12 having a pair of slide support portions 12a that are arranged to sandwich the cutting unit 20 in the extension direction of the linear cutter 21, and a connecting portion 13 that connects the cutting unit 20 to the base plate portion 11. The connection part 13 has an upper rod 14 extending perpendicularly to the base plate part 11, a lower oscillating rod 15, and a connection base part 16 to which the cutting part 20 is attached. The upper rod 14 is attached to the base plate part 11, and the lower end of the upper rod 14 and the upper end of the lower oscillating rod 15 are rotatably connected around a hinge pin 22c having a rotation axis perpendicular to the extension direction of the linear cutting tool 21 (when viewed from above in the vertical direction). The lower end of the lower oscillating rod 15 is connected to the connection base part 16, and the pair of slide support parts 12a of the follower mechanism 12 are supported by the connection base part 16, and their lower ends are disposed flush or approximately flush with the lower edge of the linear cutting tool 21 (see FIG. 4). 4 shows the state in which the extension direction of the linear cutter 21 is parallel to the horizontal plane when the cutting unit 20 is viewed from the front. The up-down direction in FIG. 4 is the vertical direction, which coincides with the X direction, which is the up-down direction of the fastening cord cutting device 10 in the state of FIG. 4, and the upper side in the figure is the upper side in the up-down direction. The left-right direction in FIG. 4 coincides with the Y direction, which is the left-right direction of the fastening cord cutting device 10 in the state of FIG. 4, and the left side in the figure is the left side in the left-right direction. The depth direction (direction perpendicular to the paper surface) in FIG. 4 coincides with the Z direction, which is the front-back direction (also called the depth direction) of the fastening cord cutting device 10 in the state of FIG. 4, and the front side in the figure is the front side in the front-back direction. The directions in the fastening cord cutting device 10 are similarly applied to the members constituting the fastening cord cutting device 10. As described above, the advancing and retreating direction in this embodiment is the vertical direction, which coincides with the X-direction. That is, in this embodiment, the fastening cord cutting device 10 advances and retreats in the vertical (up and down) direction when cutting the fastening cord 50.

[0014] 5(a) and 5(b), in this embodiment, the cutting part 20 is advanced in the forward / backward direction by the robot arm 51 (see FIG. 1) to bring the linear cutting tool 21 into contact with or close to the fastening string 50. At that time, one of the slide support parts 12a is brought into contact with the upper surface part 40a of the object 40 across which the fastening string 50 traverses (see FIG. 5(a)), and the lower swing bar 15 is swung relative to the upper bar 14 while the one of the slide support parts 12a is slid along the upper surface part 40a to bring the other slide support part 12a into contact with the upper surface part 40a (see FIG. 5(b)), and the linear cutting tool 21 is disposed along the upper surface part 40a of the object 40.

[0015] Furthermore, in this embodiment, the upper rod-shaped member 14 is attached so as to be slidable in a direction perpendicular to the base plate portion 11, and the upper rod-shaped member 14 and the lower oscillating rod-shaped member 15 are each provided in a pair in the extension direction of the linear cutting tool 21 (the left-right direction of the fastening cord cutting device 10).

[0016] In this embodiment, the hexahedral fastened object 40 fastened by the fastening string 50 is a laminate formed by vertically stacking a plurality of cardboard materials 41 before being unfolded into a cardboard box. The cardboard materials 41 are preferably used to form a so-called Type A (mandarin orange box type) cardboard box, and have a rectangular flat plate shape. The cardboard materials 41 are stacked, for example, from a dozen to several tens of sheets, vertically to form the hexahedral fastened object 40, and are fastened by the wrapped fastening string 50 so as not to come apart during transportation or delivery, and are in a hexahedral shape (see Figs. 5(a) and (b)). The fastening string may be one or more.

[0017] Moreover, the fastening string 50 for fastening the hexahedral fastened object 40 may be made of a synthetic resin known as a string material for fastening the fastened object 40. For example, it may be made of polyethylene with a melting point of 140°C. There is no particular restriction on the cross-sectional shape of the fastening string, and it may be a band-like shape with a large contact area with the fastened object. According to the present invention, the cutting portion 20 can be aligned along the surface that the fastening string crosses with a simple configuration and control. As a result, even a thin and wide band-like fastening string can be reliably cut. In this embodiment, a heat cutter using an electric heater 24 is preferably used as the cutting blade 21a forming the linear cutter 21, and the heat cutter is preferably heated to, for example, 270°C, which is lower than the melting point (about 280°C) of the cardboard material 41, and the linear cutter 21 is brought into contact with or close to the fastening string 50 crossing the upper surface 40a, preferably at the upper surface 40a of the object to be fastened 40, to cut the fastening string 50 by heat. As the linear cutter 21 that comes into contact with or close to the fastening string 50 to cut it, a cutting blade that can cut by an action other than heat, such as a metal blade or a long ultrasonic cutter, or various other linear cutters can be used in addition to a heat cutter.

[0018] In this embodiment, as shown in Figs. 1 to 4, the base plate 11 constituting the fastening cord cutting device 10 is a thick plate-like part made of synthetic resin or metal, preferably rectangular (including square), with a length in the Y direction and a length (thickness) in the Z direction of about 60 to 300 mm each independently, and a length (thickness) in the X direction of about 5 to 20 mm (see Fig. 3). The base plate 11 is provided with a plurality of fastening holes 11a that allow various members to be attached to the base plate 11 using fasteners such as bolts and screws (not shown). The base plate 11 also has two through holes (not shown) through which the upper rod member 14 of the connection portion 13 penetrates. A linear bush 11b is preferably provided as a sleeve member, coaxially with these through holes, to which the upper rod member 14 can be slidably attached in a direction perpendicular to the base plate 11.

[0019] Furthermore, the base plate portion 11 is equipped with a fixing member 17 for fixing the fastening cord cutting device 10 to the robot arm 51, an extension frame 18 for positioning the air nozzle member 25 so that it extends in front of the cutting portion 20, and a switching mechanism 19 arranged behind the linear bush 11b to enable the upper rod-shaped member 14 and the lower oscillating rod-shaped member 15 to be switched between a fixed state and an open state (see Figures 1 and 2).

[0020] As shown in Figs. 1 and 2, the fixing member 17 is a metal member having an L-shaped cross section, which is composed of a contact fixing surface portion 17a that is fixed in contact with the upper surface of the base board portion 11, and an upright fixing surface portion 17b that is bent upward from the tip edge of the contact fixing surface portion 17a (see Fig. 2). The contact fixing surface portion 17a of the fixing member 17 is disposed at a predetermined position on the upper surface of the base board portion 11, and is attached with a fastener such as a bolt or a screw (not shown). The upright fixing surface portion 17b that is vertically erected from the contact fixing surface portion 17a has a plurality of fastening holes 17c formed therein, and a selected one of these fastening holes 17c is used for fixing to the tip portion of the robot arm 51. By controlling the robot arm 51 to move in the forward and backward direction, which is the vertical direction, the robot arm 51 can be used as a forward and backward mechanism to move the fastening cord cutting device 10 fixed thereto in the forward and backward direction.

[0021] As shown in Figs. 1 and 2, the overhanging frame 18 is a member that places the air nozzle member 25 in front of the cutting section 20. Air is sprayed from the air nozzle member 25 toward one cut end 50a of the fastening string 50 cut by the linear cutter 21 of the cutting section 20 (see Fig. 8(a)). The overhanging frame 18 includes a pair of overlapping joint pieces 18a joined to the upper surface of the front side of the left and right side of the base plate 11. The overhanging frame 18 also includes a pair of overhanging plate parts 18b extending downward and forward from the outer edge of each of the overlapping joint pieces 18a. The overhanging frame 18 also includes a pair of bent plate parts 18c extending backward from the lower end part of each of the overhanging plate parts 18b via bent parts 18d. The nozzle mounting hardware 18e has a U-shaped cross section and is attached so as to be interposed between the bent portions 18d and connect the bent portions 18d.

[0022] The overlapping joint piece 18a of the overhanging frame 18 is attached to the base plate 11. The nozzle mounting hardware 18e (see FIG. 1) has both side pieces 18f of a U-shaped cross section attached to both bent portions 18d. The air nozzle member 25 is attached to the outer surface of the middle piece 18g of the nozzle mounting hardware 18e. Among the fastening holes formed in each bent portion 18d to which the side pieces 18f of the nozzle mounting hardware 18e are fastened, the fastening hole 18d' located at the lower side is an arc-shaped long hole. As a result, by shifting the position of the fastening hole 18d' formed in the side piece 18f of the nozzle mounting hardware 18e along the arc-shaped long hole, the inclination of the middle piece 18g can be changed, and the direction of air spray from the spray hole 25a of the air nozzle member 25 can be appropriately adjusted.

[0023] The switching mechanism 19, which can switch between a fixed state and an open state of the upper rod-shaped member 14 and the lower swing rod-shaped member 15, is disposed behind the linear bush 11b. The switching mechanism 19 includes a pair of contact pressing metal fittings 19a disposed to sandwich the pair of upper rod-shaped members 14 slidably inserted into each of the linear bushes 11b from both sides in the extension direction of the linear cutting tool 21, and a pressing drive device 19b for moving the pair of contact pressing metal fittings 19a back and forth in a direction parallel to the extension direction of the linear cutting tool 21. The pressing drive device 19b is preferably an air cylinder. The pressing drive device 19b is attached to the surface of the upright mounting plate 19d on the linear bush 11b side of the mounting metal fitting 19e having an L-shaped cross-sectional shape composed of a contact fixing plate 19c and an upright mounting plate 19d. Further, a pair of contact pressing metal fittings 19a are attached to the pressing drive device 19b so as to be disposed on both sides of the pair of upper rod-shaped members 14. The mounting metal fittings 19e mount the contact fixing plate 19c at a predetermined position on the rear of the base board portion 11 in a state in which the upright mounting plate 19d to which the pressing drive device 19b is attached is erected.

[0024] Each of the abutment pressure fittings 19a is an L-shaped cross-sectional part consisting of a sliding surface portion 19f connected to the pressure drive device 19b and an abutment pressure piece 19g having an L-shaped planar shape that protrudes from the upper edge of the sliding surface portion 19f in a manner that bends vertically forward. Each of the abutment pressure fittings 19a can be slid by the pressure drive device 19b in the same direction as the extension direction of the linear cutting tool 21. Each of the abutment pressure pieces 19g is arranged so that one side of the L-shaped planar shape is located on the outer side in the extension direction of the linear cutting tool 21 and the other side faces the pressure drive device 19b, that is, so that the notched portions of the L-shaped planar shape face each other (see FIG. 1). The pair of abutment pressure fittings 19a are disposed on both sides of the pair of upper rod-shaped members 14 so that the circular stoppers 14a (described later) attached to the upper ends of the upper rod-shaped members 14 are positioned inside the L-shaped planar shapes of the abutment pressure pieces 19g. The pair of abutment pressure fittings 19a slide in a direction parallel to the extending direction of the linear cutting tool 21 by the driving control of the pressing drive device 19b, so that the upper surfaces of the circular stoppers 14a come into contact with the lower surfaces of the abutment pressure pieces 19g, thereby switching between a fixed state in which the upper rod-shaped member 14 is prevented from rotating and sliding along the linear bush 11b, and an open state in which the upper rod-shaped member 14 is allowed to rotate and slide along the linear bush 11b by releasing the pressing contact with the circular stoppers 14a. In order for the pair of lower oscillating rods 15 to oscillate, the upper rod-shaped member 14 connected to each lower oscillating rod must slide. Therefore, when the sliding of each of the pair of upper rod-shaped members 14 is hindered, the pair of lower oscillating rod-shaped members 15 also consequently switch between a fixed state in which their swinging relative to the upper rod-shaped members 14 is prevented, and an open state in which their swinging is possible. In other words, the fastening cord cutting device 10 of this embodiment is equipped with a rotation prevention means that fixes the rotatable connection between the lower oscillating rod-shaped member 15 and the upper rod-shaped member 14 so that they cannot rotate.

[0025] In this embodiment, the connection part 13, which is interposed between the base plate part 11 and the cutting part 20 and connects them, is preferably configured to include a pair of upper rod-shaped members 14, a pair of lower oscillating rod-shaped members 15, and a connection base part 16 to which the cutting part 20 is attached. The upper rod-shaped members 14 are, for example, made of a round rod-shaped shaft, and are preferably inserted into the linear bushes 11b attached to the base plate part 11 so as to be slidable in a direction perpendicular to the base plate part 11, and are provided in a state in which they penetrate the base plate part 11 from top to bottom. The above-mentioned circular stopper 14a is attached to the upper end part of the upper rod-shaped member 14. The circular stopper 14a has a substantially doughnut-shaped cross section as a whole, and may be divided into two parts and fastened so as to sandwich the upper rod-shaped member 14, or a part of the circular stopper 14a may be cut in the radial direction, and the cut part may be tightened and fixed at a desired position of the upper rod-shaped member 14. Alternatively, a screw hole may be drilled in the radial direction of the circular stopper 14a, and the circular stopper 14a may be fixed to the upper bar 14 using a set bolt. An upper hinge base 22a is attached to the lower end of the upper bar 14, which preferably forms a link mechanism 22 by a hinge with the lower swing bar 15. A spring member 23 may be appropriately attached as a buffer member to the portion of the upper bar 14 between the linear bush 11b and the circular stopper 14a, and to the portion between the base plate portion 11 and the upper hinge base 22a. The spring member 23 has the effect of biasing the device itself, and the effect of preventing sliding with a light force when it is abutted against and pressed against the cardboard material 41, while maintaining a force sufficient to swing (rotate).

[0026] The lower oscillating bar 15 is also formed of, for example, a round bar-shaped shaft, and its lower end is fixed to the upper surface of the connection base 16, while a lower hinge base 22b is attached to its upper portion, forming a link mechanism 22, preferably a hinge, that enables the upper bar 14 to oscillate. The link mechanism 22 is configured by connecting an upper hinge base 22a at the lower part of the upper bar 14 and a lower hinge base 22b at the upper part of the lower oscillating bar 15 via a hinge pin 22c so as to be rotatable about a rotation axis parallel to the Z direction (see Figs. 1 and 2) of the cutting device 10. The pair of upper bar 14 and lower oscillating bar 15 is provided between the base board 11 and the connection base 16, so that it is possible to effectively prevent the connection base 16 from rotating about two axes relative to the base board 11, that is, from rotating about an axis perpendicular to the base board 11.

[0027] In this embodiment, the connection base 16 to which the lower ends of the pair of lower oscillating rods 15 are fixed is a member that supports the cutting section 20 and the follower mechanism 12, and is a thick plate-like part made of synthetic resin or metal, preferably rectangular (including square), with a length in the Y direction and a length (thickness) in the Z direction of about 50 to 100 mm, respectively, and a length (thickness) in the X direction of about 5 to 20 mm, as shown in Figures 3 and 4. The connection base 16 has a plurality of fastening holes 16a (see Figure 3) that allow various members to be attached to the connection base 16 using fasteners such as bolts and screws (not shown). In this embodiment, the connection base 16 has a protruding region 16b that protrudes forward from the portion to which the lower ends of the lower oscillating rods 15 are fixed (see Figure 3), and for example, an electric heater 24 (see Figures 1 and 2) that heats the linear cutting tool 21, which is preferably a heat cutter, is mounted on the protruding region 16b. In addition, a cutting section 20 equipped with a linear cutting tool 21 is attached to the underside of this protruding region 16b, and the linear cutting tool 21 is positioned below the front side edge portion of the connecting base portion 16, along a plane parallel to the plane on which the pair of upper rod-shaped members 14 and lower oscillating rod-shaped members 15 are arranged.

[0028] The cutting section 20 is equipped with an attachment base 20a and a linear cutting tool 21, and for example, by fixing the attachment base 20a to a predetermined position on the underside of the connecting base section 16, the linear cutting tool 21 can be positioned along a plane parallel to the plane on which the pair of upper rod-shaped members 14 and lower oscillating rod-shaped members 15 are arranged.

[0029] In this embodiment, a pair of slide support parts 12a constituting the follower mechanism 12 are attached to both sides of the connection base part 16 in an area corresponding to the part where the lower end of the lower swing rod 15 is fixed. Each slide support part 12a is composed of an attachment leg part 12b and a rotating slide part 12c provided by extending outward from the lower end part of the attachment leg part 12b. The rotating slide part 12c accommodates a free rotating member 12d made of a ball bearing, a roller, or the like, which enables the fastening string cutting device 10 to move smoothly. The attachment leg part 12b is made of a plate-like member having a front shape of a vertically elongated rectangle, for example, and is arranged so that its upper end part is fixed to the side edge part of the connection base part 16 and extends vertically downward from the connection base part 16. The lower end part of the free rotating member 12d is arranged flush or approximately flush with the cutting blade 21a, which is the linear cutting tool 21.

[0030] It is preferable that the lower end of the free rotating member 12d and the cutting blade 21a are disposed flush with each other, but the cutting blade 21a may be disposed, for example, about 0.5 mm above the lower end of the free rotating member 12d. Also, it is preferable that the free rotating member 12d is supported, for example, inside the rotating slide portion 12c via an elastic material such as a spring so as not to hinder the linear cutting tool 21 when it is pushed from above, and is retractable upward from its normal position. The movement of retracting the free rotating member 12d may be a linear movement or a rotational movement.

[0031] Furthermore, it is preferable that the freely rotating members 12d are each arranged outside the linear cutting tool 21 when viewing the fastening cord cutting device 10 from the front, and it is also preferable that they are arranged outside the pair of upper rod-shaped members 14 and lower oscillating rod-shaped members 15.

[0032] In this embodiment, an electric heater 24 for heating the linear cutting tool 21 is provided in the protruding region 16b of the connection base 16, and the linear cutting tool 21, which is a heat cutter, is provided below the front edge portion of the connection base 16. In this case, when the surface on which the pair of upper rod-shaped members 14 and lower swing rod-shaped members 15 are arranged is defined as surface α, the surface parallel to surface α on which the linear cutting tool 21 is arranged is defined as surface β, and the surface parallel to surface α on which the free rotating member 12d is arranged is defined as surface γ, surface β and surface γ are shifted considerably in the front-rear direction. The linear cutting tool 21 and the free rotating member 12d of the slide support part 12a can also be arranged so that surface α and surface γ coincide with each other. This suppresses the generation of moment in the Z-axis direction on the hinge pin 22c when the free rotating member 12d comes into contact with the cardboard material, so the sliding of the upper rod 14 and the swinging of the lower swinging rod 15 become smooth without being fixed. Furthermore, the strength required for the hinge pin 22c can be reduced, and as a result, the hinge pin 22c can be made smaller, so that the fastening cord cutting device 10 can be made lightweight and compact.

[0033] To use the fastening cord cutting device 10 of this embodiment to cut the fastening cord 50 fastening a hexahedral-shaped laminate of multiple layers of cardboard material 41 to the fastened object 40, preferably at the top surface 40a of the fastened object 40, the fastening cord cutting device 10 is controlled by controlling the robot arm 51 to which the fastening cord cutting device 10 is attached, and using the robot arm 51 as an advance / retract mechanism, the fastening cord cutting device 10 is advanced toward the top surface 40a of the fastened object 40 in the vertical direction toward the top surface 40a of the fastened object 40, with the advance / retract direction being the vertical direction toward the top surface 40a of the fastened object 40.

[0034] As shown in Fig. 5(a), (b) and Fig. 6(a)-(c), for example, in the case where the upper surface 40a of the object 40 is a surface inclined obliquely from the surface where the cutting tool of the cutting part 20 is provided, when the fastening cord cutting device 10 is moved to bring the linear cutting tool 21 into contact with or close to the fastening cord 50 so as to preferably cross perpendicularly, the free rotating member 12d of one of the slide support parts 12a first abuts against one side of the surface part across which the fastening cord 50 crosses, the fastening cord 50 to be cut (see Fig. 5(a)). After that, when the fastening cord cutting device 10 is further advanced, one of the pair of lower swinging rod members 15 swings to one side above the slope relative to the upper rod member 14 on one side, and one of the slide support parts 12a slides to one side above the slope along the surface part across which the fastening cord crosses, accompanying the rotation of the free rotating member 12d. At the same time, preferably the pair of upper rod-shaped members 14 slide up and down appropriately along the linear bushing 11b, and the other of the pair of lower oscillating rod-shaped members 15 swings upwardly on an incline relative to the other upper rod-shaped member 14, thereby enabling the free rotating member 12d of the other sliding support portion 12a to smoothly abut against the other side of the fastening string 50, as shown in Figure 5(b).

[0035] In this way, the linear cutting tool 21 of the cutting portion 20 is arranged along the upper surface 40a across which the fastening string 50 of the fastened object 40 traverses, and crosses and comes into contact with or close to the entire width of the fastening string 50 traversing the upper surface 40a. This makes it possible to completely cut the fastening string 50 reliably and smoothly without leaving any part of the fastening string 50 uncut, i.e., so-called "uncut portion."

[0036] In other words, according to the fastening cord cutting device 10 of this embodiment, preferably using the robot arm 51 as an advance / retract mechanism, the fastening cord cutting device 10 can be moved forward and backward toward the surface of the fastened object 40 across which the fastening cord 50 crosses, and the fastening cord can be cut even if the surface is tilted or distorted from the horizontal plane, with a simple configuration and control.

[0037] For example, as shown in Figs. 6(a) to (c), the upper surface 40a of the object 40 formed by stacking a plurality of cardboard sheets 41 may be inclined in a direction perpendicular to the direction in which the fastening string 50 crosses, in which the linear cutting tool 21 of the cutting part 20 is arranged (see Fig. 6(c)), and may also be inclined in the direction in which the fastening string 50 crosses (see Fig. 6(b)). In this case, since the linear cutting tool 21 of the cutting part 20 is literally linear, it can be easily arranged so as to contact or be close to the upper surface 40a over its entire width, even if the cutting part 20 does not follow the inclination of the upper surface 40a due to the inclination in the direction in which the fastening string 50 crosses. Therefore, it is considered that the inclination of the upper surface 40a in the direction perpendicular to the extension direction of the linear cutting tool 21 (the direction in which the fastening string 50 crosses) does not adversely affect the cutting.

[0038] In this embodiment, two sets (pairs) of upper rod-shaped members 14 and lower oscillating rod-shaped members 15 are provided between the base board 11 and the connection base 16 in order to prevent the connection base 16 from rotating about two axes relative to the base board 11, that is, about an axis perpendicular to the base board 11. The upper rod-shaped member 14 is slidable along the linear bush 11b in order to simultaneously oscillate the pair of lower oscillating rod-shaped members 15 relative to the upper rod-shaped member 14 via the respective link mechanisms 22. As will be described later, only one set of upper rod-shaped members 14 and lower oscillating rod-shaped members 15 connecting the base board 11 and the connection base 16 may be provided. In this case, the sliding portion for sliding the upper rod-shaped member 14 may be configured using an LM guide or a ball spline in order to prevent the connection base 16 from rotating about two axes, that is, about an axis perpendicular to the base board 11. It is also preferable to provide a biasing means (not shown) such as a spring between the base plate portion 11 and the connecting base portion 16 so that the upper rod-shaped material 14 naturally returns to its initial position when there is no need to slide the upper rod-shaped material 14 along the sliding portion.

[0039] Furthermore, in this embodiment, as a means for switching to a fixed state in which the lower oscillating rod 15 does not oscillate relative to the upper rod 14 when the fastening cord cutting device 10 is moved at high speed, for example, during a retreat operation, a direct-acting air cylinder 26 may be fixed to the underside of the base board 11, for example, as shown in Fig. 7, instead of the above-mentioned switching mechanism 19. The air cylinder 26 is disposed between the base board 11 and the connection base 16, and is a rotation prevention means that can press the connection base 16 by moving a lower end abutment part 26a back and forth, and fix the lower oscillating rod 15 so that it does not oscillate with the link mechanism 22.

[0040] In this embodiment, as shown in FIG. 1, the air nozzle member 25 is attached to the middle piece 18g of the nozzle mounting hardware 18e at the tip of the above-mentioned overhanging frame 18, which is supported by the base board 11 and overhangs forward, with the injection hole 25a facing diagonally downward. By connecting, for example, an air hose to the connection nozzle 25b of the air nozzle member 25 and feeding compressed air, as shown in FIG. 8(a), air can be injected from the injection hole 25a to one cut end 50a of the fastening string 50 cut by the linear cutting tool 21 of the cutting section 20. This allows the cut end of the fastening string 50 to be moved from the cut position, and preferably the fastening string 50 is removed from the upper surface portion. In order to effectively exert such a function, it is preferable that the direction in which air is injected from the injection hole 25a is an angle θ of, for example, about 10 to 45° with respect to the upper surface portion 40a of the fastening object 40. The air nozzle member 25 may also be provided on the rear side of the linear cutter 21 of the cutting section 20 to spray air onto the other cut end 50b of the fastening string 50 (see FIG. 8(b)). This allows the end of the fastening string 50 to be moved from the cutting position, and preferably the fastening string 50 is removed from the upper surface. This is preferable because the fastening string 50 does not get in the way when handling the stacked cardboard material 41 to be removed from the top of the fastened part. It is also preferable from the viewpoint of preventing erroneous detection when the imaging device recognizes the position of the fastening string 50 to be cut.

[0041] In this embodiment, as shown in FIG. 9, a cut string suction device 27 may be installed on the other cut end 50b side of the fastening string 50 cut by the linear cutter 21 to suck the cut end 50b. When sucking the fastening string 50 by the cut string suction device 27, it is preferable to recognize the position of the fastening string 50 by an imaging device or the like, and to place the cut string suction device 27 so that the center positions of the fastening string 50 and the suction nozzle 27a (see FIGS. 10(a) to (c)) of the cut string suction device 27 coincide with each other. The distance between the suction nozzle 27a of the cut string suction device 27 and the fastening string 50 (cut end 50b) is preferably an appropriate distance to reliably suck the other cut end 50b of the fastening string 50, and therefore it is preferable that the suction nozzle 27a can also advance and retreat in the direction toward the fastening object 40. It is also possible to make it possible to eject compressed air from above so that the other cut end 50b of the fastening string 50 can be moved toward the suction nozzle 27a. The suction of the fastening string 50 can also be monitored on the upper surface 40a by a photoelectric surface sensor, and by making part of the piping connected to the suction nozzle 27a out of transparent resin, it is possible to sense the passage of the cut fastening string 50.

[0042] As shown in Figs. 10(a) to (c), the fastening objects 40 may be stacked vertically in multiple tiers. In this case, when the cut end 50b of the fastening string 50 of the upper fastening object 40 hangs down, the knots of the upper and lower fastening strings may get caught on each other, which may hinder the removal of the fastening string (see Figs. 10(b) and (c)). In order to prevent this problem, it is preferable to place a string receiving guide 50d on the side of the lower fastening object as shown in Fig. 11. This prevents the fastening string 50 of the upper fastening object 40 from coming into contact with the fastening string 50 of the lower fastening object 40. As a result, it is possible to effectively prevent the knots 50c from getting caught on each other.

[0043] As described above, only one set of upper rod member 14 and lower oscillating rod member 15 constituting connection portion 13 that connects base plate portion 11 and cutting portion 20 may be provided. In this case, from the viewpoint of preventing rotation about an axis perpendicular to base plate portion 11, it is preferable to use an LM guide or a ball spline. Even if only one set of upper rod-shaped member 14 and lower oscillating rod-shaped member 15 which are swingably connected via a link mechanism 22 is provided, as shown in Figures 12(a) and (b), when the linear cutting tool 21 constituting the fastening cord cutting device 10 is brought into contact with or close to the fastening cord 50 by the advance / retract mechanism of the robot arm 51 against the upper surface 40a of the object to be fastened 40 which is inclined obliquely from a plane perpendicular to the advance / retract direction so as to preferably intersect with the fastening cord 50 perpendicularly, if the free rotating member 12d of one of the sliding support parts 12a abuts against one side of the boundary of the fastening cord 50 to be cut (see Figure 12(a)), and the fastening cord cutting device 10 is moved further, the lower oscillating rod-shaped member 15 will swing to one side above the incline relative to the upper rod-shaped member 14, and one of the sliding support parts 12a will slide and move toward the upper side of the incline along the surface across which the fastening cord 50 crosses. Accordingly, the free rotating member 12d of the other slide support part 12a smoothly abuts against the other side of the fastening string 50 (see FIG. 12(b)), and the linear cutting tool 21 of the cutting part 20 comes into contact with or approaches along the upper surface part 40a of the fastening object 40 across which the fastening string 50 crosses. This makes it possible to completely cut the fastening string 50 reliably and smoothly without leaving any "uncut portions," just as in the case where two sets of upper rod-shaped member 14 and lower oscillating rod-shaped member 15 are provided.

[0044] 13 illustrates each step of the fastening cord cutting method using the fastening cord cutting device 10 of this embodiment. That is, the fastening cord cutting method using the fastening cord cutting device 10 of this embodiment includes the steps of moving the fastening cord cutting device 10, for example, from a retreated position to a portion of the upper surface 40a of the hexahedral fastened object 40 across which the fastening cord 50 traverses, preferably with the above-mentioned switching mechanism 19 or air cylinder 26, while the lower swinging rod 15 is fixed so as not to swing relative to the upper rod 14; switching the lower swinging rod 15 from the fixed state so as not to swing to an open state, and advancing the fastening cord cutting device 10 by the forward / backward mechanism until the pair of slide support parts 12a come into contact with the upper surface 40a of the fastened object 40 across which the fastening cord 50 traverses, thereby positioning the cutting part 20 along the upper surface 40a; and cutting the fastening cord by the linear cutter 21.

[0045] With the fastening cord cutting method of this embodiment, the fastening cord 50 can be cut even if the surface across which the fastening cord 50 crosses is inclined or distorted from a plane parallel to the surface of the cutting section 20 on which the cutting tool is provided.

[0046] In the fastening cord cutting method of this embodiment, in the process of moving the fastening cord cutting device 10 to a portion opposite the fastening cord 50 wound around the fastened object 40, it is preferable to recognize the position of the fastening cord 50 using a position recognition means, and to position the fastening cord cutting device 10 so that the center of the width of the fastening cord 50 coincides with the center of the extension direction of the linear cutting tool 21.

[0047] The present invention is not limited to the above embodiment and various modifications are possible. For example, the hexahedral object to be fastened by the fastening string does not necessarily have to be a laminate formed by stacking a plurality of sheet-like articles or a plurality of thin plate-like articles one above the other, and may be an assembled cardboard box or various other box-shaped containers. When the object to be fastened is a laminate formed by stacking a plurality of sheet-like articles or a plurality of thin plate-like articles one above the other, the sheet-like articles or thin plate-like articles may be various sheet-like or thin plate-like articles in addition to cardboard materials. The surface of the object to be fastened, which is cut by the fastening string and which is crossed by the fastening string, does not necessarily have to be the top surface of the hexahedral shape, and may be a side surface or a bottom surface. The fastening string cutting device can also be moved forward and backward or forward in a horizontal or oblique direction toward the surface of the hexahedral object to be fastened, which is crossed by the fastening string, preferably by control of a robot arm. The advance / retract mechanism does not necessarily have to be a robot arm; various mechanisms can be used that are capable of advancing and retreating the fastening cord cutting device toward the surface of the hexahedral-shaped fastened object across which the fastening cord crosses. [Explanation of symbols]

[0048] 10 Fastening cord cutting device 11 Base board section 11a Fixing hole 11b Linear bushing 12 Tracking mechanism 12a Slide support part 12b Mounting foot 12c Rotating slide part 12d Freely rotating member 13 Connection 14 Upper bar 14a Circular stopper 15 Lower swing bar 16 Connection base 16a Fixing hole 16b Overhang area 17 Fastening member 17a Contact fixed surface part 17b Standing fixed surface part 17c Fastening hole 18 Extension frame 18a Lap joint piece 18b Extension plate part 18c Bent plate section 18d Bending part 18d' Fastening hole 18e Nozzle mounting hardware 18f Side piece 18g middle piece 19 Switching mechanism 19a Contact pressure fittings 19b Pressing drive device 19c Contact Fixing Plate 19d Vertical mounting plate 19e Mounting hardware 19f Slide surface 19g Contact pressure piece 20 Cut section 20a Mounting base 21 Linear cutting tool 21a cutting blade 22 Link mechanism 22a Upper hinge base 22b Lower hinge base 22c hinge pin 24 Electric heater 25 Air nozzle component 25a injection hole 25b Connection nozzle 26 Air Cylinder 26a Lower end contact part 27 Cutting string suction device 27a Suction nozzle 40 Object to be fastened 40a Upper surface portion (surface portion across which the fastening string crosses) 41 Cardboard 50 Fastening cord 50a One cut end 50b The other cut end 50c knot 51 Robot arm (advance and retreat mechanism) X Up and down direction of the fastening cord cutting device (advance and retreat direction) Y: Left-right direction of the fastening cord cutting device (extension direction of the linear cutting tool) Z Depth direction of the fastening cord cutting device (front-to-back direction)

Claims

1. A fastening cord cutting device for cutting a fastening cord wrapped around a hexahedral object at the surface where the fastening cord crosses, A base plate portion to which a reciprocating mechanism is connected that moves the cutting device toward the surface of the fastening string crossing the fastened object, A cutting section is provided with a linear cutting tool that is positioned to intersect with the fastening cord and to contact or be close to the fastening cord in order to cut the fastening cord. A tracking mechanism having a pair of slide support parts arranged on either side of the cutting portion in the extending direction of the linear cutting tool, It is configured to include a connecting portion that connects the cutting portion and the base plate portion, The connecting portion comprises an upper rod-shaped member extending perpendicularly from the base plate portion, a lower oscillating rod-shaped member, and a connecting base portion to which the cut portion is attached. The upper rod-shaped member is attached to the base plate portion, The lower end of the upper rod-shaped member and the upper end of the lower oscillating rod-shaped member are rotatably connected about a rotation axis perpendicular to the extending direction of the linear cutting tool. The lower end of the lower oscillating rod-shaped member is connected to the connecting base portion. A fastening cord cutting device in which a pair of slide support parts of the tracking mechanism are supported by the connecting base part, and their lower ends are positioned flush or substantially flush with the lower end edge of the linear cutting tool.

2. The fastening string cutting device according to claim 1, wherein when the linear cutting tool is brought into contact with or close to the fastening string by the advancement and retraction mechanism, one of the slide support parts is brought into contact with the surface to which the fastening string passes, the lower oscillating rod-shaped material is oscillated with respect to the upper rod-shaped material, and the one of the slide support parts is slid along the surface to which the fastening string passes, thereby bringing the other slide support part into contact with the surface to which the fastening string passes, and positioning the linear cutting tool along the surface to which the fastening string passes.

3. The fastening cord cutting device according to claim 1 or 2, wherein the hexahedral object to be fastened is a laminate formed by stacking a plurality of sheet-like articles or a plurality of thin plate-like articles vertically.

4. The fastening cord cutting device according to claim 1 or 2, wherein the surface through which the fastening cord passes is the upper surface of the hexahedron-shaped object to be fastened.

5. The fastening cord cutting device according to claim 1 or 2, wherein the upper rod-shaped member and the lower oscillating rod-shaped member are round rod-shaped shafts.

6. The fastening cord cutting device according to claim 1 or 2, wherein the upper rod-shaped material is mounted so as to be slidable in a direction perpendicular to the base plate portion.

7. The fastening cord cutting device according to claim 6, wherein the upper rod-shaped member and the lower oscillating rod-shaped member of the connecting portion are provided as a pair in the extending direction of the linear cutting tool.

8. The fastening cord cutting device according to claim 1 or 2, further comprising a rotation-preventing means for fixing the rotatable connection between the lower oscillating rod-shaped member and the upper rod-shaped member so that it cannot rotate.

9. The fastening cord cutting device according to claim 1 or 2, further comprising an air nozzle member for spraying air onto the cut end of the fastening cord.

10. The fastening cord cutting device according to claim 1 or 2, wherein the linear cutting tool cuts the fastening cord by heat.

11. The fastening cord cutting device according to claim 1 or 2, wherein the forward and backward movement mechanism is a robot arm.

12. The fastening cord cutting device according to claim 1 or 2, wherein the slide support portion includes a freely rotating member such as a ball bearing or roller.

13. A method for cutting a fastening cord using the fastening cord cutting device described in claim 1 or 2, The process of moving the fastening cord cutting device to the portion of the hexahedral object to be fastened that is facing the fastening cord on the surface where the wrapped fastening cord crosses, The process of moving the fastening cord cutting device by the advancement mechanism until the pair of slide support parts each contact the surface of the fastening cord that the fastening cord crosses the fastened object, thereby positioning the linear cutting tool so that it is in contact with or close to the fastening cord, The process includes the step of cutting the fastening cord with the positioned linear cutting tool, In the step of positioning the linear cutting tool, if the surface of the object to be fastened through which the fastening string passes is not parallel to the base plate, the method of cutting a fastening string involves first bringing one of the slide support parts into contact with the surface of the object to be fastened through which the fastening string passes by extending the reciprocating mechanism, then swinging the lower oscillating rod-shaped material relative to the upper rod-shaped material, and sliding the one of the slide support parts along the surface of the object to be fastened through which the fastening string passes by, thereby bringing the other slide support part into contact with the surface of the fastening string passes by, and positioning the linear cutting tool along the surface of the object to be fastened through which the fastening string passes.

14. The fastening string cutting method according to claim 13, wherein in the step of moving the fastening string cutting device to a portion facing the fastening string, the position of the fastening string is recognized by a position recognition means, and the fastening string cutting device is positioned so that the center of the fastening string in the width direction coincides with the center of the linear cutting tool in the extension direction.

Images