Cutting device for cardboard box

Abstract

To provide a cutting device for a cardboard box capable of cutting the cardboard box safely, reliably, efficiently and inexpensively without producing cutting waste.SOLUTION: A cardboard box cutting device 1 of the present invention comprises: a cardboard box holding device 9 which acts on a top surface 5 of a cardboard box B and an opposing side surface 7 near the top surface 5 to hold the cardboard box; a first vertical movement mechanism 11 vertically moving the cardboard box holding device 9; a cutter device 13 which acts on the side surface 7 at a predetermined height position F near the top surface 5 of the cardboard box B to cut it; and a second vertical movement mechanism 19 vertically moving a lifting platform 17 equipped with a horizontal movement mechanism 15 horizontally moving the cutter device 13 in a first direction K along the side surface 7 of the cardboard box B and in a second direction L perpendicular to the first direction K. The cutting device 13 is configured to include a disk-shaped mounting plate 27, a disk-shaped copying plate 29, and a plurality of thin, flat cutter blades 31 that are sandwiched and attached between these.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a cardboard box cutting device used when opening a packed cardboard box, and more particularly to a cardboard box cutting device capable of cutting a cardboard box accurately and efficiently without producing cutting waste even if the cardboard box to be cut is deformed or misaligned. [Background technology]

[0002] When opening a large number of packed cardboard boxes, the packed cardboard boxes are put onto an unpacking line, and a cardboard box cutting device arranged on the unpacking line is used to cut and remove a part of the packed cardboard boxes, for example a part of the top side, and the contents contained within the cardboard boxes are taken out. Such cardboard box cutting devices include those shown in the following Patent Documents 1 to 3. Of these, Patent Document 1 discloses a cardboard box cutting device that uses thick circular saw-shaped rotary blades arranged close to the four sides of the cardboard box to be cut, cutting two sides at a time in two separate steps. This device also includes a cardboard box holding device that holds the cardboard box by clamping the four bottom side faces of the cardboard box to be cut.

[0003] Patent Document 2 discloses a cardboard box cutting device that acts on the top surface of a cardboard box to be cut, sequentially cutting the four peripheral sides while changing the orientation and position of the cardboard box. Like Patent Document 1, this device also uses a thick circular saw-shaped rotary blade, and a flat tracing plate that moves in tandem with the rotary blade is provided separately, and by acting on the top surface of the cardboard box to be cut, this tracing plate makes it possible to accurately cut the cardboard box by following the undulations of the top surface of the cardboard box. Furthermore, Patent Document 3 discloses a cardboard box cutting device in which a rotating thick, polygonal, flat cutting tool without a blade is attached to the tip of a robot arm and the cutting tool acts on the four sides of the cardboard box to cut it. This device is also equipped with a dust collector for collecting cutting chips generated when the cardboard box is cut by the cutting tool. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2001-146216 A [Patent Document 2] Japanese Patent Application Publication No. 10-53233 [Patent Document 3] Patent Publication No. 2021-130175 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the above Patent Documents 1 to 3, thick rotary blades and thick cutting tools are used, which generates cutting chips when cutting the cardboard box. In this case, if the contents contained in the cardboard box are food such as crude tea, refined tea, or miscellaneous grains, the inclusion of the cutting chips in the contents can be a major problem. In addition, in the above-mentioned Patent Document 1, four cardboard box cutting devices are provided on the unpacking line to individually cut the four sides of each cardboard box, while in the above-mentioned Patent Document 2, a robot arm and a dust collector are used, which creates the problem that the equipment is large-scale and increases the equipment costs.

[0006] Furthermore, when the thick rotary blades used in Patent Documents 1 and 2 or the thick cutting tool used in Patent Document 3 become worn or damaged, the entire rotary blade or cutting tool must be removed from the device and replaced, which requires a considerable amount of effort, time, and parts costs. Furthermore, in the above-mentioned Patent Document 1, the structure of the cardboard box holding device is such that four clamping plates simply clamp the four bottom side surfaces of the cardboard box, so there is a concern that the cardboard box may move when being cut, making it impossible to cut the cardboard box accurately.

[0007] Furthermore, in the case of cardboard box cutting devices configured to cut the four side edges of a cardboard box as in Patent Documents 1 and 3, when cutting two adjacent faces connected in an L shape, the respective cutting lines may be misaligned in the height direction, making it impossible to separate the cardboard box. On the other hand, in the case of a cardboard box cutting device configured to cut the four periphery sides of the top surface of a cardboard box as in Patent Document 2, such a problem does not occur if the adjacent cutting lines are arranged to intersect, but the cutting chips generated by the cutting go directly into the cardboard box below, making the above-mentioned mixing of cutting chips with the contents more noticeable.

[0008] The present invention has been made based on these points, and its object is to provide a cardboard box cutting device that is simple in structure and inexpensive, which can cut cardboard boxes accurately and efficiently without causing deformation or misalignment of the cardboard box, and without producing cutting waste, using a cutter blade that is easy to maintain and inexpensive. [Means for solving the problem]

[0009] In order to achieve the above object, a cardboard box cutting device according to claim 1 of the present invention is a cardboard box cutting device used for acting on a packed cardboard box to separate a main body part containing contents from a closing part containing no contents, the cutting device comprising: a cardboard box holding device which acts on an upper surface of the cardboard box and an opposing side surface near the upper surface to hold the packed cardboard box; a first vertical movement mechanism which moves the cardboard box holding device between an upper retracted position and a lower holding position; a cutter device which acts on a side surface at a predetermined height position near the upper surface of the cardboard box to form a cutting line for cutting the side surface; and a cutting mechanism which moves the cutter device horizontally in a first direction along the side surface of the cardboard box and in a second direction perpendicular to the first direction which moves the cutter device toward and away from the side surface of the cardboard box. and a second vertical movement mechanism having a lifting stand mounted with the horizontal movement mechanism and configured to move the lifting stand between an upper standby position and a lower cutting position and to adjust the cutting height position of the cutter device. The cutter device is characterized in that it comprises an upwardly extending mounting shaft connected to the output shaft of a motor via a coupling, a disk-shaped mounting plate attached integrally to the lower end of the mounting shaft, a disk-shaped tracing plate attached so as to be overlapped below the mounting plate, a plurality of thin, flat cutter blades whose base sides are partially sandwiched between the mounting plate and the tracing plate and whose tip sides protrude in the protruding direction by a predetermined cutting depth, and a plurality of fixing bolts which fix the mounting plate, the tracing plate, and the cutter blades.

[0010] In addition, the cardboard box cutting device according to claim 2 is characterized in that, in the cardboard box cutting device described in claim 1, the cutter blade is a replacement blade for a cutter knife used when manually opening cardboard boxes, etc.

[0011] In addition, the cardboard box cutting device according to claim 3 is a cardboard box cutting device according to claim 1, characterized in that the cutter device is mounted so that the cutter blade is inclined at a predetermined cutting angle from the horizontal.

[0012] Furthermore, the cardboard box cutting device according to claim 4 is the cardboard box cutting device described in claim 1, wherein the cutter device further comprises a safety cover covering the cutter blade and capable of moving a predetermined stroke in the second direction, a first biasing spring of a predetermined spring constant which biases the safety cover in the protruding direction, a slide mechanism which enables the integrated mounting plate, tracing plate and cutter blade to move a predetermined stroke in the second direction, and a second biasing spring of a predetermined spring constant which biases the integrated mounting plate, tracing plate and cutter blade in the protruding direction, and the spring constant of the first biasing spring is set to be smaller than the spring constant of the second biasing spring.

[0013] In addition, the cardboard box cutting device according to claim 5 is the cardboard box cutting device described in claim 1, characterized in that the cutter devices and horizontal movement mechanisms are provided in multiple sets corresponding to the number of sides of the cardboard box to be cut, and these multiple sets of cutter devices and horizontal movement mechanisms are used to cut all of the sides of the cardboard box to be cut at once.

[0014] Further, the cardboard box cutting device according to claim 6 is the cardboard box cutting device according to claim 1, characterized in that the cardboard box holding device comprises a flat pressure plate that presses and holds the top surface of the cardboard box, at least a pair of clamping plates with an L-shaped cross section that act on opposing side surfaces near the top of the cardboard box and the outer edges of the top surface connected to the side surfaces to hold the cardboard box in a clamped state, a first positioning pin that penetrates into the top surface of the cardboard box to hold the cardboard box, and a second positioning pin that penetrates into opposing side surfaces near the top of the cardboard box to hold the cardboard box. Effect of the Invention

[0015] The above-mentioned means provide the following effects. That is, according to the cardboard box cutting device of the present invention, since a plurality of thin, flat cutter blades are used as cutting means instead of the conventional thick rotary blades or cutting tools, no cutting chips are produced when cutting the cardboard box. In addition, there is no risk of cutting chips getting into the cardboard box after opening and mixing with the contents. In addition, since no cutting chips are produced, there is no need to install large-scale equipment such as a dust collector, and when the blade becomes dull, maintenance is easy because the fixing bolts can be loosened and only the cutter blade can be replaced.

[0016] Furthermore, if a replacement blade for a cutter knife used when manually opening cardboard boxes or the like is used as the cutter blade, it will be easy to obtain and the parts cost will be low. Furthermore, when the cutter blade is installed so that it is inclined at a specified cutting angle from the horizontal, even if there is a slight deviation in the height direction between the cutting lines of two adjacent sides, it is possible to separate the main body portion and the blocking portion within the range of overlap.

[0017] In addition, if the cutter device further comprises a safety cover which can move a predetermined stroke in the second direction to cover the cutter blade, a first biasing spring with a predetermined spring constant which biases the safety cover in the protruding direction, a slide mechanism which enables the integrated mounting plate, tracing plate and cutter blade to move a predetermined stroke in the second direction, and a second biasing spring with a predetermined spring constant which biases the integrated mounting plate, tracing plate and cutter blade in the protruding direction, and the spring constant of the first biasing spring is set to be smaller than the spring constant of the second biasing spring, the cutter blade is completely covered by the safety cover when not cutting and is safe, and when cutting, the safety cover first comes into contact with the side of the cardboard box to be cut, and while maintaining this contact state, the cutter blade is exposed and can be used to act on the side of the cardboard box to be cut.

[0018] When the cutter blade is further pressed in, the side of the cardboard box comes into contact with the peripheral surface of the tracing plate, and the cutter blade penetrates into the cardboard box by a specified cutting depth. When the cutter blade is further pressed in, the second biasing spring begins to contract, and the integrated mounting plate, tracing plate, and cutter blade repeatedly move forward and backward in response to the undulations and irregularities of the side of the cardboard box to be cut, tracing the side and proceeding with the cutting. Furthermore, since the spring constant of the first biasing spring biasing the safety cover at this time is smaller than the spring constant of the second biasing spring, the tip of the safety cover is always in contact with the side of the cardboard box being cut and the cutter blade is prevented from being exposed during cutting, ensuring safety during operation.

[0019] Furthermore, if multiple sets of cutter devices and horizontal movement mechanisms are provided corresponding to the number of sides of the cardboard box to be cut, and these multiple sets of cutter devices and horizontal movement mechanisms are used to cut all of the sides of the cardboard box at once, the main body and closing parts of the cardboard box can be separated quickly, making the opening of the cardboard box even more efficient.

[0020] Furthermore, if the cardboard box holding device is configured to include a flat pressure plate that presses and holds the top surface of the cardboard box, at least a pair of clamping plates with an L-shaped cross section that act on opposing side surfaces near the top of the cardboard box and the outer edges of the top surface connected to those sides to hold the cardboard box in a clamped state, a first positioning pin that penetrates into the top surface of the cardboard box to hold the cardboard box, and a second positioning pin that penetrates into opposing side surfaces near the top of the cardboard box to hold the cardboard box, the cardboard box to be cut can be fixed more securely, making it possible to cut the cardboard box more accurately and safely. [Brief description of the drawings]

[0021] [Figure 1] FIG. 1 is a perspective view showing an embodiment of the present invention, illustrating a cutting device for cardboard boxes. [Diagram 2]FIG. 1 is a front view showing a cardboard box cutting device according to an embodiment of the present invention. [Diagram 3] FIG. 1 is a diagram showing an embodiment of the present invention, and is a plan view showing a cardboard box cutting device. [Figure 4] FIG. 1 is a diagram showing an embodiment of the present invention, and is a plan view showing a cutter device. [Diagram 5] FIG. 5 is a cross-sectional view taken along line AA in FIG. 4 showing the cutter device, illustrating the embodiment of the present invention. [Figure 6] FIG. 5 is a cross-sectional view taken along line BB in FIG. 4 showing the cutter device, illustrating the embodiment of the present invention. [Figure 7] FIG. 2 is a perspective view showing an embodiment of the present invention, in which a mounting plate, a copy plate, and a cutter blade of a cutter device are disassembled. [Figure 8] FIG. 1 is a perspective view showing a cardboard box holding device, a first vertical movement mechanism, and a front-rear movement mechanism according to an embodiment of the present invention. [Figure 9] FIG. 1 is a front view showing a cardboard box holding device according to an embodiment of the present invention. [Figure 10] FIG. 1 is a diagram showing an embodiment of the present invention, and is a plan view showing a cardboard box holding device. [Figure 11] FIG. 2 is a diagram showing an embodiment of the present invention, and is an explanatory diagram showing the relationship between the cutting angle and cutting depth of a cutter blade. [Figure 12] FIG. 2 is a diagram showing an embodiment of the present invention, and is an explanatory diagram showing the conditions for cutting lines to be formed on two adjacent side surfaces. [Figure 13] FIG. 1 is a front view showing an embodiment of the present invention, illustrating steps of the movement from when a cardboard box is carried in to when cutting of the cardboard box begins. [Figure 14] FIG. 1 is a front view showing a step-by-step movement until a cardboard box is held, according to an embodiment of the present invention. [Figure 15] FIG. 11 is a bottom view showing the steps of the movement of the safety cover and the slide mechanism of the cutter device, illustrating the embodiment of the present invention. [Figure 16]FIG. 13 is a bottom view showing the movement of the cutter device in response to changes in the shape of the cardboard box, according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] The configuration and operation of the cardboard box cutting device of the present invention will be specifically described below by taking the illustrated embodiment as an example. In the following description, the overall configuration of the cardboard box cutting device of the present invention will be described first, followed by a description of the specific configuration of the main parts of the cardboard box cutting device of the present invention, and then a description of the relationship between the cutting angle and cutting depth of the cutter blade and the conditions for the cutting lines formed on two adjacent side surfaces.

[0023] Next, the operating mode of the cardboard box cutting device configured in this manner will be explained, dividing it into the movements from when the cardboard box is brought in to when cutting begins, the movements until the cardboard box is held, and the movements of the safety cover and slide mechanism of the cutter device. Furthermore, the operation and effect of the cardboard box cutting device thus constructed will be described, and then finally, another embodiment having a partially different configuration from the above embodiment will be briefly described.

[0024] (1) Overall configuration of the cardboard box cutting device (see Figures 1 to 6) The cardboard box cutting device 1 of the present invention is used as an example, arranged in a cardboard box unpacking line 2 which unpacks a large number of cardboard boxes B. The cardboard box unpacking line 2 is composed of, for example, a roller conveyor, and in the unpacking area A where the cardboard box cutting device 1 of the present invention is arranged, positioning bars and stoppers (not shown) corresponding to the size and shape of the cardboard box B to be opened are provided as an example, and the cardboard box B is guided to a predetermined position and stopped by these positioning bars and stoppers. Then, the cardboard box cutting device 1 of the present invention, which will be described in detail below, acts on the cardboard box B stopped at a predetermined position, and the cardboard box B is opened by being separated into a main body portion 3 containing the contents C and a closed portion 4 containing no contents C.

[0025] Specifically, the cardboard box cutting device 1 of the present invention includes a cardboard box holding device 9 that acts on the top surface 5 of the cardboard box B and opposing side surfaces, such as 7L and 7R, close to the top surface 5 to hold the packed cardboard box B, a first vertical movement mechanism 11 that moves the cardboard box holding device 9 between an upper retracted position D and a lower holding position E, and a cutter device 1 that acts on the side surfaces 7L, 7R, 7A, and 7B at a predetermined height position F close to the top surface 5 of the cardboard box B to form cutting lines G, H, I, and J that cut these side surfaces 7L, 7R, 7A, and 7B. 3, a horizontal movement mechanism 15 which moves the cutter device 13 horizontally in a first direction K along the side surfaces 7L, 7R and 7A, 7B of the cardboard box B and in a second direction L perpendicular to the first direction K in which the cutter device 13 approaches and moves away from the side surfaces 7L, 7R and 7A, 7B of the cardboard box B, and a second vertical movement mechanism 19 which has a lifting stand 17 on which the horizontal movement mechanism 15 is mounted, moves the lifting stand 17 between an upper waiting position M and a lower cutting position N, and adjusts the cutting height position F of the cutter device 13.

[0026] As a configuration of the present invention, the cutter device 13 is configured by comprising: a mounting shaft 25 extending upward and connected to the output shaft 24 of the motor 23 via the coupling 21; a disk-shaped mounting plate 27 attached integrally to the lower end of the mounting shaft 25; a disk-shaped copying plate 29 attached so as to be overlapped below the mounting plate 27; a plurality of flat, thin-walled cutter blades 31, part of whose base side is sandwiched between the mounting plate 27 and the copying plate 29 and whose tip side is arranged to protrude a predetermined cutting depth O in the protruding direction L1; and a plurality of fixing bolts 33 for fixing the mounting plate 27, the copying plate 29 and the cutter device 31.

[0027] (2) Specific configuration of the main parts of the cardboard box cutting device (see Figures 1 to 10) The cutter device 13 further includes a safety cover 35 which covers the cutter blade 31 and is movable a predetermined stroke in the second direction L, a first biasing spring 37 of a predetermined spring constant P which biases the safety cover 35 in the protruding direction L1, a slide mechanism 39 which enables the integrated mounting plate 27, the tracing plate 29 and the cutter blade 31 to move a predetermined stroke in the second direction L, and a second biasing spring 41 of a predetermined spring constant Q which biases the integrated mounting plate 27, the tracing plate 29 and the cutter blade 31 in the protruding direction L1. The slide mechanism 39 further includes an abutment piece 44 provided on the lower surface of the rear end of the mounting base 43 of the motor 23 which restricts the movable range of the tracing plate 29 in the backward direction L2, and a stopper bolt 47 provided on the upper surface of the rear end of a support base 45 which is a part of the housing of the slide mechanism 39.

[0028] The safety cover 35 is a hollow, flat box-shaped member with a semicircular front when viewed from above and a rectangular rear when viewed from above, with the surface facing the cardboard box B being open. A safety cover base 36 is provided at an upper position in sliding contact with the upper surface of the safety cover 35, and the above-mentioned first biasing spring 37 is compressed between the safety cover 35 and the safety cover base 36. The slide mechanism 39 has a guide rod 51 supported horizontally by two support posts 49, 49 standing up from the front and rear ends of the upper surface of the support base 45 described above, and a slide guide 53 fitted around the guide rod 51 and sliding in the second direction L. The slide guide 53 is connected to the mounting base 43 of the motor 23 described above, and is configured to move in the same direction when the mounting base 43 moves in the protruding direction L1 or the retracting direction L2.

[0029] The second biasing spring 41 is fitted onto the outside of the guide rod 51 so as to be compressed between the support post 49 at the rear end of the support base 45 and the slide guide 53. In addition, at this time, the spring constant P of the first biasing spring 37 biasing the safety cover 35 is set to 1.5 N / mm to 2 N / mm, whereas the spring constant Q of the second biasing spring 41 of the slide mechanism 39 is set to 7.5 N / mm to 10 N / mm, so that the spring constant P of the first biasing spring 37 is set to be about five times larger than the spring constant Q of the second biasing spring 41 of the slide mechanism 39 (P <Q)。 In addition, in this embodiment, as shown in FIG. 7, four screw holes 28 are provided at equal intervals in the circumferential direction in the mounting plate 27, and a positioning recess 56 is formed in the center of the underside of the mounting plate 27 to fit with a protrusion 55 raised from the center of the upper surface of the copying plate 29.

[0030] As shown in FIG. 7, in this embodiment, four cutter blades 31 are provided so that the blades are aligned in the direction of rotation, and as an example, replacement blades for a commercially available cutter knife used when manually opening cardboard boxes B, etc. are used. In this embodiment, a medium-sized single blade having a thickness of 0.5 mm, a width of 18 mm, and a length of 100 mm is used as an example. However, the cutter blade 31 is not limited to this size and shape, and replacement blades for cutter knives of various sizes, such as large and small, can be used. Further, a mounting hole 32 for passing the shaft of a fixing bolt 33 is formed at the base of the cutter blade 31 .

[0031] The copying plate 29 is a disk-shaped member having a diameter approximately the same as that of the mounting plate 27 described above, and the lower part of its side surface is machined into a tapered shape, for example narrowing downward, in accordance with the cutting angle θ of the cutter blade 31. Four countersunk portions 57 for mounting the above-mentioned four cutter blades 31 so that they face in the tangential direction, for example, are provided at equal intervals in the circumferential direction on the upper surface of the copying plate 29 near the outer periphery. Each countersunk portion 57 is formed with an attachment hole 30 for passing the shaft portion of the fixing bolt 33 therethrough, similar to the attachment hole 32 of the cutter blade 31.

[0032] The cutter device 13 thus configured is attached to the horizontal movement mechanism 15 via a mounting bracket 59 as shown in FIGS. The mounting bracket 59 is a plate-shaped member that is bent so that the base portion 59a attached to the horizontal movement mechanism 15 is horizontal, the middle portion 59b is vertical, and the tip portion 59c is, for example, inclined slightly upward. The cutter device 13 attached to this tip portion 59c is also, for example, attached in a position that is inclined slightly upward. As a result, the cutter blade 31 is configured to be attached in a position inclined by a predetermined cutting angle θ from the horizontal. In this embodiment, the cutting angle θ is set to 20°, for example. When the cutter blade 31 is mounted so that it is inclined at a specified cutting angle from the horizontal, even if there is a slight deviation in the height direction between the cutting lines of the two adjacent sides, it is possible to separate the main body portion 3 and the blocking portion 4 within the range of overlap. As a result, the start and end of the cut on each side intersect and the cutting line is continuous all around, allowing the main body portion 3 and the blocking portion 4 to be separated.

[0033] In addition, in this embodiment, the cutting depth O of the cutter blade 31 protruding from the peripheral surface of the copying plate 29 is set to 20 mm, for example. The horizontal movement mechanism 15 is configured by combining a first slide mechanism 61 for moving the cutter device 13 in a first direction K along the side surface 7 of the cardboard box B, and a second slide mechanism 63 (in this embodiment, as an example, two slide mechanisms are provided corresponding to the two side surfaces) for moving the cutter device 13 in a second direction L perpendicular to the first direction K, approaching and moving away from the side surface 7 of the cardboard box B, and these two slide mechanisms 61, 63 are configured, as an example, by rodless air cylinders.

[0034] The second vertical movement mechanism 19 comprises a lifting platform 17 assembled into a rectangular frame shape as shown in Figures 1 and 3, four sliders 65 attached to the outer surfaces of the four corners of the lifting platform 17, and four guide rails 67 extending in the vertical direction Z and engaging with these sliders 65. Four first slide mechanisms 61 of the horizontal movement mechanism 15 described above are installed in a crisscross pattern on the upper surface of the lifting platform 17 as shown in Figures 1 and 3. By driving a drive device not shown, the lifting platform 17 can be moved between an upper waiting position M and a lower cutting position N, and the cutting height position F of the cutter device 13 can be adjusted. Incidentally, in this embodiment, the target is a cardboard box B in which no contents C are present within an area 50 mm below the top surface 5, and to be on the safe side, the cutting height position F is set to a position 20 to 30 mm below the top surface 5 of the cardboard box B.

[0035] In addition, in this embodiment, four sets of cutter devices 13 and horizontal movement mechanisms 15 are provided corresponding to the number of sides 7 of the cardboard box B to be cut, which is four, and these four sets of cutter devices 13 and horizontal movement mechanisms 15 are configured to be used to cut all sides 71L, 7R, 7A, 7B of the cardboard box B to be cut in one go. The cardboard box holding device 9 is basically composed of a flat pressure plate 69 that presses and holds the top surface 5 of cardboard box B, opposing side surfaces 7L, 7R near the top surface 5 of cardboard box B, a pair of clamping plates 71L, 71R with an L-shaped cross section that act on the outer edge of the top surface 5 connected to the side surfaces 7L, 7R to hold cardboard box B in a clamped state, a first positioning pin 73 that penetrates into the top surface 5 of cardboard box B to hold cardboard box B, and a second positioning pin 75 that penetrates into opposing side surfaces 7L, 7R near the top surface 5 of cardboard box B to hold cardboard box B.

[0036] An air cylinder 77 for driving the first positioning pin 73, and air cylinders 79L, 79R for driving the clamping plates 71L, 71R are provided on the upper surface side of the pressing plate 69. Incidentally, a plurality of the second positioning pins 75 are provided, and are attached to the left and right sandwiching plates 71L, 71R in such a manner that they protrude inward. Furthermore, the pressure plate 69 has, for example, four connecting rods 81 extending upward from its upper surface, and is configured to be connected to the first vertical movement mechanism 11 described below via these connecting rods 81.

[0037] The first vertical movement mechanism 11 is a mechanism for moving the cardboard box holding device 9 described above between an upper retracted position D and a lower holding position E. Specifically, as shown in FIG. 8, the skeleton is formed by having two fixed plates, an upper plate 83 and a lower plate 85, four guide rods 87 standing at the corners between them, and four sliders 89 that engage with these four guide rods 87, for example a gate-shaped movable frame 91.

[0038] Furthermore, as an example, two air cylinders 93 each have a main body 93a extending upward from the upper plate 83, and the ends of their cylinder rods 93b are connected to the upper surface of the movable frame 91 below. Furthermore, the connecting rod 81 of the cardboard box holding device 9 described above is connected to the lower surface of the lower plate 85 of the first vertical movement mechanism 11.

[0039] In addition, in this embodiment, as shown in Figure 8, the movable frame 91 is provided with a forward / backward movement mechanism 95 for moving the cardboard box holding device 9 together with the first vertical movement mechanism 11 to the discharge area S and the upside-down area T. The forward / backward movement mechanism 95 is provided with a long horizontal support plate 97 which is fixed horizontally on the outer frame such as the support frame of the unpacking line 2, and two air cylinders 99A, 99B for movement to the discharge area S which is located on the upper surface of the horizontal support plate 97 and for movement to the top-bottom inversion area T, and the sliders of these air cylinders 99A, 99B are connected to the movable frame 91 of the first vertical movement mechanism 11.

[0040] (3) Relationship between cutter blade cutting angle and cutting depth (see Figure 11) The relationship between the cutting angle θ and the cutting depth O of the cutter blade 31 is as shown in Fig. 11. In this embodiment, the cutting angle θ is set to 20° and the cutting depth O is set to 20 mm, as an example. In addition, in the figure, cardboard box B at the position indicated by the solid line indicates cardboard box B in a reference state where no deformation or positional shift has occurred, and cardboard box B at the position indicated by the imaginary line indicates cardboard box B at the maximum scanning amount U where deformation and positional shift have occurred.

[0041] In the drawing, the length indicated by the symbol U indicates the tracing amount, which is the maximum movement length of the tracing plate 29 moving in the tracing direction V. In the drawing, the symbol X indicates the cutting height, which is the displacement in the height direction Z from the base to the tip of the cutter blade 31 that has entered the cardboard box B. Furthermore, in the figure, the symbol Y indicates the tracing height, which is the displacement in the height direction Z when the tracing plate 29 moves by the tracing amount U, and in the figure, the symbol W indicates the deformation amount of the cardboard box B, which is the distance in the second direction L before and after the deformation of the cardboard box B. The relationship between the cutting height X and the cutting depth O is X = O × sin20° = 6.84 mm, the relationship between the tracing height Y and the tracing amount U is Y = U × sin20°, and the relationship between the deformation amount W and the tracing amount U is W = U × cos20°.

[0042] (4) Conditions for the cutting lines to be formed on two adjacent sides (see Figure 12) FIG. 12 illustrates two cutting lines I and H formed on two adjacent sides 7A and 7R of a cardboard box B that are offset in the height direction Z, and the incision height X at each cutting position. In order for these two cutting lines I and H to intersect and be cut, it is necessary for their respective cutting heights X to overlap, and the condition for this is that the tracing height Y<the cutting height X. Furthermore, if the variation in the height direction Z is ±1 mm, the amount of deformation W that can be cut off is W<±{(X-1) / cos70°×cos20°}<±16.05 mm.

[0043] (5) Operation of the cardboard box cutting device (see Figures 13 to 16) Next, the operating mode of the cardboard box cutting device 1 according to this embodiment configured as described above will be explained by dividing it into (A) the movement from when the cardboard box is brought in to when cutting begins, (B) the movement until the cardboard box is held, and (C) the movement of the safety cover and slide mechanism of the cutter device. (A) Movement from bringing in the cardboard box to starting cutting (see Figure 13) When a cardboard box B is placed on the cardboard box unpacking line 2 and reaches a designated position in the unpacking area A where the actual unpacking takes place, the cardboard box holding device 9 is located in an upper retracted position D, and the cutter device 13, horizontal movement mechanism 15 and lifting stand 17 are each located in an upper standby position M, as shown in Figure 13(a).

[0044] When cardboard box B reaches a designated position in unpacking area A, the movement of cardboard box B is stopped as shown in Figure 13(b), and the cylinder rod 93b of the air cylinder 93 of the first vertical movement mechanism 11 is extended downward, causing the cardboard box holding device 9 to begin descending. 13(c), when the cardboard box holding device 9 reaches the holding position E, as described below, the cardboard box holding device 9 starts operating to hold the cardboard box B. In addition, the drive device (not shown) starts operating, and the cutter device 13, the horizontal movement mechanism 15, and the lifting stand 17 start moving toward the cutting position N.

[0045] When the cutter device 13, horizontal movement mechanism 15 and lifting platform 17 reach the cutting position N as shown in FIG. 13(d), their descent is stopped and cutting of the cardboard box B begins. That is, the first slide mechanism 61 of the horizontal movement mechanism 15 is operated to move the cutter blade 31 in the first direction K from the cutting start position to the cutting end position. Furthermore, the second slide mechanism 63 of the horizontal movement mechanism 15 is operated to move the cutter blade 31 against the side surface 7 of the cardboard box B to be cut, and the cutter blade 31 is advanced to a predetermined cutting depth O, thereby starting cutting.

[0046] (B) Movement up to holding the cardboard box (see Figure 14) When the pressing plate 69 of the holding device 9 for the cardboard box reaches the upper surface 5 of the cardboard box B, it presses the cardboard box B with a predetermined pressing force as shown in FIG. 14(a). Next, as shown in FIG. 14(b), the air cylinder 77 is operated to lower the first positioning pin 73 so that the first positioning pin 73 pierces the upper surface 5 of the cardboard box B.

[0047] 14(c), the left and right air cylinders 79L, 79R are operated to clamp and hold the cardboard box B between the left and right clamping plates 71L, 71R. At the same time, the second positioning pins 75 are thrust into the sides 7L, 7R of the cardboard box B to hold the cardboard box B more securely, and cutting of the cardboard box B begins. After cutting, the forward / backward movement mechanism 95 is operated to move the separated blocking portion 4 to the discharge area S while holding it, and the second positioning pin 75 and the first positioning pin 73 are removed in that order, causing the blocking portion 4 to fall naturally and be discharged.

[0048] (C) Movement of the cutter safety cover and slide mechanism (see Figures 15 and 16) Before the cutter device 13 comes into contact with the cardboard box B, as shown in Fig. 15(a), the safety cover 35 is in the most protruding state in the protruding direction L1 by the biasing force of the first biasing spring 37, and the slide mechanism 39 is also in the most protruding state in the protruding direction L1 by the biasing force of the second biasing spring 41. When a part of the cardboard box B comes into contact with the inclined case part 35a which is a part of the safety cover 35, as shown in Fig. 15(b), the safety cover 35 is moved in the retreat direction L2 against the biasing force of the first biasing spring 37 to expose the cutter blade 31 from the peripheral surface on the front end side of the safety cover 35.

[0049] When the peripheral surface of the imitation plate 29 comes into contact with a part of the cardboard box B, as shown in Fig. 15(c), the imitation plate 29 is moved in the retreat direction L2 against the biasing force of the second biasing spring 41. Also, at this time, since the spring constant P of the first biasing spring 37 that biases the safety cover 35 is smaller than the spring constant Q of the second biasing spring 41 of the slide mechanism 39 (P < Q), the peripheral surface on the front end side of the safety cover 35 maintains the state of being in contact with the cardboard box B. Also, the movements of the safety cover 35 and the slide mechanism 39 are also executed at any time depending on the undulations and differences in unevenness of the side surface 7 of the cardboard box B to be cut, as shown in Figs. 16(a) and (b).

[0050] And according to the cardboard box cutting device 1 according to the present embodiment configured in this way, the cardboard box B can be cut without generating cuttings, and since the cutter blade 31 that is inexpensive and easy to attach and detach can be used, maintenance is also facilitated. Also, it can cope with cases where the cardboard box B is deformed or displaced, and by improving and ensuring the holding force of the cardboard box, accurate and safe cutting of the cardboard box B can be efficiently executed with simple equipment.

[0051] [Other Embodiments] The cardboard box cutting device 1 of the present invention is not limited to the one in the above-described embodiment, and can be modified within the scope of the gist of the invention. For example, the number of cutter blades 31 attached to the cutter device 13 is not limited to four, but may be three, or five or more. In addition, the attachment direction of the cutter blades 31 is not limited to the tangential direction of the tracing plate 29, but may be the normal direction or an intermediate inclined direction between these.

[0052] It is also possible to provide a turntable on the unpacking line 2 and use a set of cutter device 13 and horizontal movement mechanism 15 to cut cardboard box B while changing its orientation by 90° at a time. In addition, it is also possible to provide two types of horizontal movement mechanisms 15, one for the long sides corresponding to the long sides of cardboard box B and one for the short sides corresponding to the short sides of cardboard box B, so that the cardboard boxes B on the unpacking line 2 can be cut in stages along the long and short sides separately. In addition, it is possible to use other actuators such as motor cylinders instead of the air cylinders used in various driving parts, and it is also possible to add a structure that allows the cutting angle θ of the cutter blade 31 to be adjusted. [Industrial Applicability]

[0053] The cardboard box cutting device of the present invention can be used in work sites where a large number of packed cardboard boxes are opened, and is particularly usable in work sites where the mixing of cutting scraps into the contents after opening is a problem, and in work sites where safe, reliable cutting of cardboard boxes is desired to be achieved efficiently and at low cost. [Explanation of symbols]

[0054] 1. Cardboard box cutting device 2. (Cardboard box) unpacking line 3 Main body 4 Occlusion 5 Top side 7. Aspect 9. Cardboard box holding device 11 1st vertical movement mechanism 13 Cutter device 15 Horizontal movement mechanism 17 Lifting platform 19 Second vertical movement mechanism 21 Coupling 23 Motor 24 Output 25 Mounting shaft 27 Mounting plate 28 screw holes 29 Copying board 30 Mounting holes 31 Cutter blade 32 Mounting holes 33 Fixing bolt 35 Safety Cover 35a Inclined guide section 36 Safety cover base 37 First biasing spring 39 Slide mechanism 41 Second biasing spring 43 Mounting base 44 Contact piece 45 Support Base 47 Stopper bolt 49 Support Post 51 Guide rod 53 Slide Guide 55 Convex 56 Recess 57 Counterbore 59 Mounting bracket 59a base 59b Middle part 59c Tip 61 First slide mechanism 63 Second slide mechanism 65 Slider 67 Guide Rail 69 Pressure Plate 71 Clamping plate 73 First positioning pin 75 Second positioning pin 77 Air Cylinder 79 Air Cylinder 81 Connecting rod 83 Top plate 85 Bottom plate 87 Guide Rod 89 Slider 91 Movable Frame 93 Air Cylinder 93a Main unit 93b Cylinder rod 95 Back and forth movement mechanism 97 Horizontal support plate 99 Air Cylinder A Unpacking Area B. Cardboard box C Contents D Evacuation position E Holding position F (cutting) height position G cutting line H cutting line I cutting line J cutting line K 1st direction L 2nd direction L1 protrusion direction L2 Reverse direction M Standby position N Cutting position O Cutting depth P spring constant Q Spring constant θ Cutting angle Z Up / Down direction (height direction) S Discharge Area T Inverted Area U tracing amount V tracing direction X Cutting height Y tracing height W deformation amount

Claims

1. A cardboard box cutting device used to act on a packed cardboard box to separate a main body portion containing contents from a closing portion containing no contents, a cardboard box holding device that acts on a top surface of the cardboard box and a side surface facing the top surface to hold the packed cardboard box; a first vertical movement mechanism for moving the cardboard box holding device between an upper retracted position and a lower holding position; a cutter device that acts on a side surface of a cardboard box at a predetermined height position near the top surface thereof to form a cutting line for cutting said side surface; a horizontal movement mechanism that moves the cutter device horizontally in a first direction along a side surface of the cardboard box and in a second direction perpendicular to the first direction, the second direction moving toward and away from the side surface of the cardboard box; a second vertical movement mechanism having a lifting platform on which the horizontal movement mechanism is mounted, for moving the lifting platform between an upper standby position and a lower cutting position and for adjusting the cutting height position of the cutter device; The cutter device for cardboard boxes comprises an upwardly extending mounting shaft connected to the output shaft of a motor via a coupling, a disk-shaped mounting plate attached integrally to the lower end of the mounting shaft, a disk-shaped copy plate attached so as to be overlapped below the mounting plate, a plurality of flat, thin-walled cutter blades whose base sides are partially clamped between the mounting plate and the copy plate and whose tip sides protrude in the protruding direction by a predetermined cutting depth, and a plurality of fixing bolts for fixing the mounting plate, the copy plate, and the cutter blades.

2. 2. The cardboard box cutting device according to claim 1, wherein the cutter blade is a replacement blade for a cutter knife used when manually opening cardboard boxes or the like.

3. 2. The cardboard box cutting device according to claim 1, wherein the cutter device is mounted so that the cutter blade is inclined at a predetermined cutting angle from the horizontal.

4. The cutter device includes a safety cover that covers the cutter blade and is movable a predetermined stroke in the second direction. a first biasing spring having a predetermined spring constant for biasing the safety cover in a protruding direction; a slide mechanism that allows the integral mounting plate, copying plate, and cutter blade to move a predetermined stroke in the second direction; a second biasing spring having a predetermined spring constant for biasing the integral mounting plate, the copy plate, and the cutter blade in a protruding direction, 2. The cardboard box cutting device according to claim 1, wherein the spring constant of the first biasing spring is set to be smaller than the spring constant of the second biasing spring.

5. The cardboard box cutting device as described in claim 1, characterized in that multiple sets of cutter devices and horizontal movement mechanisms are provided corresponding to the number of sides of the cardboard box to be cut, and these multiple sets of cutter devices and horizontal movement mechanisms are used to cut all of the sides of the cardboard box to be cut at once.

6. The cardboard box holding device includes a flat pressing plate that presses and holds the upper surface of the cardboard box; At least one pair of clamping plates having an L-shaped cross section that act on opposing side surfaces near the top of the cardboard box and on outer edges of the top surface connected to the side surfaces to hold the cardboard box in a clamped state; a first positioning pin that is inserted into an upper surface of the cardboard box to hold the cardboard box; 2. The cardboard box cutting device according to claim 1, further comprising: a second positioning pin for holding the cardboard box by piercing an opposing side surface near the top of the cardboard box.

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