Cutting device, corrugated cardboard sheet manufacturing method, corrugated cardboard sheet manufacturing device, and corrugated cardboard sheet

Abstract

A cutting device for cutting a corrugated cardboard sheet that is formed by adhering together a flat liner and an inner medium having a plurality of flute ridges forming a corrugated shape, wherein the corrugated cardboard sheet is cut along a cutting line following a direction which is slanted by a prescribed angle relative to a direction following the flute ridges.

Description

Cutting device, method for manufacturing a cardboard sheet, cardboard sheet manufacturing apparatus, and cardboard sheet

[0001] The present disclosure relates to a cutting device, a method for manufacturing a cardboard sheet, a cardboard sheet manufacturing apparatus, and a cardboard sheet.

[0002] A corrugating machine as a cardboard sheet manufacturing apparatus includes a single facer and a double facer. The single facer processes the core into a waveform and laminates the back liner to form a single-sided cardboard sheet. The double facer laminates the front liner to the single-sided cardboard sheet to form a double-sided cardboard sheet. The double-sided cardboard sheet in which the back liner, the core, and the front liner are laminated is cut to a predetermined width and then cut to a predetermined length to manufacture a cardboard sheet.

[0003] Examples of such a cardboard sheet manufacturing apparatus include those described in the following patent documents.

[0004] Japanese Unexamined Patent Application Publication No. 2023-183697

[0005] A cardboard sheet is formed by laminating a core having a waveform between a back liner and a front liner. The cardboard sheet is processed with folding score lines by a box-making machine, and grooves, glue margin pieces, hand holes, etc. are also processed. The core is processed into a waveform along the width direction orthogonal to the conveyance direction of the cardboard sheet, thereby forming a plurality of ridges. The score lines are formed along a direction orthogonal or parallel to the ridges of the core in the cardboard sheet. When a score line is formed along the ridges of the core in the cardboard sheet, if the score line is formed between the tops of adjacent ridges, the folding position of the cardboard sheet may not be stable, and there is a risk of folding defects.

[0006] Also, when the cardboard sheet is folded along the score line to form a cardboard box, the cardboard box can ensure sufficient strength against the stress acting along the direction parallel to the ridges of the core. On the other hand, the cardboard box may have insufficient strength against the stress acting along the direction orthogonal to the ridges of the core.

[0007] This disclosure aims to solve the aforementioned problems and to provide a cutting device and a method for manufacturing corrugated cardboard sheets, as well as a corrugated cardboard sheet manufacturing device and corrugated cardboard sheets, that improve bending accuracy and strength.

[0008] To achieve the above objective, the cutting apparatus of the present disclosure cuts a corrugated cardboard sheet formed by bonding together at least one flat liner and a core having a plurality of corrugated ridges, and cuts the corrugated cardboard sheet into a parallelogram shape along a cutting line that is inclined by a predetermined angle with respect to the direction along the ridges.

[0009] Furthermore, the present disclosure relates to a method for manufacturing a corrugated cardboard sheet, which is formed by bonding at least one flat liner and a core having a plurality of corrugated ridges, wherein the corrugated cardboard sheet is cut into a parallelogram shape along a cutting line that is inclined by a predetermined angle with respect to the direction along the corrugated ridges.

[0010] Furthermore, the corrugated cardboard sheet manufacturing apparatus of this disclosure comprises a sheet laminating apparatus that forms a corrugated cardboard sheet by laminating at least one flat liner and a core having a plurality of corrugated ridges in a wave shape, and a cutting apparatus that cuts the corrugated cardboard sheet.

[0011] Furthermore, the corrugated cardboard sheet of the present disclosure is a corrugated cardboard sheet formed by bonding at least one flat liner and a core having a plurality of corrugated ridges, wherein the sheet has a parallelogram shape in plan view, two opposing first sides are perpendicular to the direction along the ridges, and two opposing second sides are inclined by a predetermined angle with respect to the direction along the ridges.

[0012] The cutting device, corrugated cardboard sheet manufacturing method, corrugated cardboard sheet manufacturing device, and corrugated cardboard sheet of this disclosure can improve bending accuracy and strength.

[0013] Figure 1 is a schematic diagram showing a corrugated machine as a corrugated cardboard sheet manufacturing apparatus of this embodiment. Figure 2 is a side view showing a cutting device of this embodiment. Figure 3 is a plan view showing a general cutting device. Figure 4 is a plan view showing a cutting device of this embodiment. Figure 5 is a plan view showing a modified example of the cutting device of this embodiment. Figure 6 is a schematic diagram for explaining the adjustment angle of the cutting device. Figure 7 is a side view showing a reduction gear. Figure 8 is a plan view showing a reduction gear. Figure 9 is a side view showing a conveying device and a stopping device. Figure 10 is a block diagram showing the control system of the corrugated machine. Figure 11 is an explanatory diagram of the cutting angle based on pitch. Figure 12 is an explanatory diagram of the cutting angle based on cutting width. Figure 13 is a side view showing a first modified example of the arrangement of knife cylinders in the cutting device. Figure 14 is a side view showing a second modified example of the arrangement of knife cylinders in the cutting device. Figure 15 is a side view showing a third modified example of the arrangement of knife cylinders in the cutting device. Figure 16 is a side view showing a fourth modified example of the arrangement of knife cylinders in the cutting device. Figure 17 is a plan view showing a double-sided corrugated cardboard sheet of this embodiment. Figure 18 is a plan view showing a double-sided corrugated cardboard sheet after die-cutting. Figure 19 is a plan view showing a single-sided corrugated cardboard sheet after die-cutting.

[0014] Preferred embodiments of the present disclosure will be described in detail below with reference to the drawings. However, these embodiments do not limit the present disclosure, and where there are multiple embodiments, they may be combinations of these embodiments. Furthermore, the components in the embodiments include those readily conceivable by those skilled in the art, those that are substantially identical, and those that are equivalent.

[0015] <Corrugated Machine> The corrugated cardboard sheet manufacturing apparatus of this embodiment is applied to a corrugated machine. Figure 1 is a schematic diagram representing a corrugated machine. In the following description, the longitudinal direction of the corrugated machine will be referred to as the X direction, the horizontal direction perpendicular to the longitudinal direction (X direction) of the corrugated machine will be referred to as the Y direction (width direction of the corrugated cardboard sheet), and the vertical direction perpendicular to the longitudinal direction (X direction) of the corrugated machine (thickness direction of the corrugated cardboard sheet) will be referred to as the Z direction. The conveying direction of the corrugated cardboard sheet is along the X direction, which is the longitudinal direction of the corrugated machine.

[0016] As shown in Figure 1, the corrugating machine 10 manufactures a single-sided corrugated cardboard sheet D1 by laminating a back liner C1 onto a corrugated core B1. Next, a front liner A is laminated onto the core B1 of the manufactured single-sided corrugated cardboard sheet D1 to manufacture a continuous double-sided corrugated cardboard sheet. Then, by cutting the continuous double-sided corrugated cardboard sheet to a predetermined length, a sheet-shaped double-sided corrugated cardboard sheet can be manufactured.

[0017] Furthermore, the corrugating machine 10 manufactures a single-sided corrugated cardboard sheet D2 by laminating a back liner C2 onto a corrugated core B2. Next, it manufactures a continuous double-sided corrugated cardboard sheet by laminating a front liner A onto the core B2 of the manufactured single-sided corrugated cardboard sheet D2. Then, by cutting the continuous double-sided corrugated cardboard sheet to a predetermined length, a sheet-shaped double-sided corrugated cardboard sheet can be manufactured.

[0018] Furthermore, the corrugating machine 10 manufactures a single-sided corrugated cardboard sheet D1 by laminating a back liner C1 onto a corrugated core B1, and also manufactures a single-sided corrugated cardboard sheet D2 by laminating a back liner C2 onto a corrugated core B2. Next, the back liner C2 of the single-sided corrugated cardboard sheet D2 is laminated onto the core B1 of the manufactured single-sided corrugated cardboard sheet D1, and the front liner A is laminated onto the core B2 of the single-sided corrugated cardboard sheet D2 to manufacture a continuous double-sided corrugated cardboard sheet.

[0019] As described above, the corrugated cardboard machine 10 can manufacture double-sided corrugated cardboard sheets by laminating a front liner A onto a single-sided corrugated cardboard sheet D1 or a single-sided corrugated cardboard sheet D2. It can also manufacture a double-sided corrugated cardboard sheet by laminating a single-sided corrugated cardboard sheet D1, a single-sided corrugated cardboard sheet D2, and a front liner A. The following description will focus on the case of manufacturing a double-sided corrugated cardboard sheet.

[0020] The corrugated machine 10 includes a mill roll stand 11 for the core B1, a mill roll stand 12 for the back liner C1, a single facer 13, a bridge 14, a mill roll stand 15 for the core B2, a mill roll stand 16 for the back liner C2, a single facer 17, a bridge 18, a mill roll stand 19 for the front liner A, a preheater 20, a glue machine 21, a double facer 22, a rotary slicer 23, a slitter scorer 24, a cutoff 25, a defective product discharge device 26, and a stacker 27.

[0021] The mill roll stands 11 and 15 are equipped with rolls of paper on both sides in the X direction, each containing cores B1 and B2 wound into a roll, and splicers 31 and 32 are provided between each roll of paper for splicing. When one roll of paper is being fed, the other roll is loaded and preparation for splicing is made, and when one roll of paper becomes nearly empty, the splicers 31 and 32 splice the other roll of paper onto the first roll. Therefore, cores B1 and B2 are continuously fed from each mill roll stand 11 and 15 toward the downstream side.

[0022] The mill roll stands 12 and 16 are equipped with rolls of paper on both sides in the X direction, each with a back liner C1 and C2 wound into a roll. Splicers 33 and 34 are provided between each roll of paper for splicing. When one roll of paper is being fed, the other roll is loaded and preparation for splicing is made. When one roll of paper becomes nearly empty, the splicers 33 and 34 splice the other roll onto the first roll. Therefore, the back liners C1 and C2 are continuously fed from each mill roll stand 12 and 16 downstream.

[0023] The cores B1 and B2, which are fed out from the mill roll stands 11 and 15, and the back liners C1 and C2, which are fed out from the mill roll stands 12 and 16, are preheated by preheaters (not shown). Each preheater has a heating roll into which steam is supplied, and the cores B1 and B2 and the back liners C1 and C2 are wrapped around the heating roll and conveyed, thereby raising the temperature to a predetermined level.

[0024] The single facer 13 processes the heated core B1 into a corrugated shape, then glues it to each corrugated top, and attaches the heated back liner C1 to form a single-sided corrugated cardboard sheet D1. The single facer 13 has a lifting conveyor 29 at the exit of the single-sided corrugated cardboard sheet D1, and transports the single-sided corrugated cardboard sheet D1 formed by the single facer 13 to the bridge 14. The bridge 14 temporarily holds the single-sided corrugated cardboard sheet D1 to absorb the speed difference between the single facer 13 and the double facer 22.

[0025] The single facer 17 processes the heated core B2 into a corrugated shape, then glues it to each corrugated top, and attaches the heated back liner C2 to form a single-sided corrugated cardboard sheet D2. The single facer 17 has a lifting conveyor 29 at the exit of the single-sided corrugated cardboard sheet D2, which is used to transport the single-sided corrugated cardboard sheet D2 formed by the single facer 17 to the bridge 18. The bridge 18 temporarily holds the single-sided corrugated cardboard sheet D2 to absorb the speed difference between the single facer 17 and the double facer 22.

[0026] Furthermore, the paper guide device 30 is provided at the exit portions of bridges 14 and 18. The paper guide device 30 adjusts the Y-direction positions of single-sided corrugated cardboard sheets D1 and D2 between bridges 14 and 18 and the double facer 22.

[0027] The mill roll stand 19 has rolls of paper with the front liner A wound into a roll on both sides in the X direction, and a splicer 35 is provided between each roll of paper for splicing. When one roll of paper is being fed, the other roll of paper is loaded and prepared for splicing, and when one roll of paper is running low, the splicer splices the other roll of paper onto the first roll. Therefore, the front liner A is continuously fed from the mill roll stand 19 downstream.

[0028] The preheater 20 has three preheating rolls 41, 42, and 43 arranged in the Z direction. Preheating roll 41 heats the outer liner A, preheating roll 42 heats the single-sided corrugated cardboard sheet D2, and preheating roll 43 heats the single-sided corrugated cardboard sheet D1. Each preheating roll 41, 42, and 43 has a winding amount adjustment device (not shown) and is heated to a predetermined temperature by steam being supplied to its interior, and preheating is performed by winding the outer liner A, single-sided corrugated cardboard sheet D2, and single-sided corrugated cardboard sheet D1 around its circumferential surface.

[0029] The glue machine 21 has gluing devices 44 and 45 arranged side by side in the Z direction. The gluing device 44 contacts each top of the corrugated core B2 in the single-sided corrugated cardboard sheet D2, which has been heated by the preheating roll 42, and applies glue. The gluing device 45 contacts each top of the corrugated core B1 in the single-sided corrugated cardboard sheet D1, which has been heated by the preheating roll 43, and applies glue. The single-sided corrugated cardboard sheets D1 and D2, which have been glued by the glue machine 21, are transferred to the double facer 22 in the next process. The outer liner A, which has been heated by the preheating roll 41, is also transferred to the double facer 22 by passing through the glue machine 21.

[0030] The double facer 22 has an upstream heating section 36 and a downstream cooling section 37 along the transport line of the single-sided corrugated cardboard sheet D1 or D2 and the outer liner A. The single-sided corrugated cardboard sheet D1 or D2 and the outer liner A, glued together by the glue machine 21, are transported between the pressure belt and the hot plate in the heating section 36, and are transported together as a single unit in an overlapping state toward the cooling section 37. During this transport, the single-sided corrugated cardboard sheet D1 or D2 and the outer liner A are heated under pressure, causing them to bond together to form a continuous double-sided corrugated cardboard sheet E, which is then naturally cooled while being transported.

[0031] The double-sided corrugated cardboard sheet E produced by the double facer 22 is transferred to the slitter scorer 24. The slitter scorer 24 cuts the wide double-sided corrugated cardboard sheet E along the X direction to a predetermined width and processes creases extending in the X direction. The slitter scorer 24 consists of a first slitter scorer unit 46 and a second slitter scorer unit 47, which have substantially the same structure and are arranged along the X direction of the double-sided corrugated cardboard sheet E. The wide double-sided corrugated cardboard sheet E is cut by the slitter scorer 24 to form a double-sided corrugated cardboard sheet E of a predetermined width.

[0032] The cut-off 25 cuts the double-sided corrugated cardboard sheet E, which has been cut in the X direction by the slitter scorer 24, along the Y direction to form a plate-shaped double-sided corrugated cardboard sheet F of a predetermined length. The defective product discharge device 26 discharges the double-sided corrugated cardboard sheets F that have been determined to be defective by the defective detection device described later from the conveyor line. The defective product discharge device 26 has a discharge conveyor and a sorting roll, although it is not shown in the figure. When the plate-shaped double-sided corrugated cardboard sheets F that have been determined to be defective are conveyed, the sorting roll descends and sorts the defective plate-shaped double-sided corrugated cardboard sheets F to the discharge conveyor for discharge. The stacker 27 stacks the double-sided corrugated cardboard sheets F that have been determined to be good products and discharges them outside the machine as products.

[0033] <Cutting device> Figure 2 is a side view of the cutting device of this embodiment, Figure 3 is a plan view of a general cutting device, and Figure 4 is a plan view of the cutting device of this embodiment. The cutoff 25 as a cutting device cuts a continuous double-sided corrugated cardboard sheet E to form a plate-shaped double-sided corrugated cardboard sheet F. In the following description, the cores B1 and B2 will be collectively referred to as core B, the back liners C1 and C2 will be collectively referred to as back liner C, and the single-sided corrugated cardboard sheets D1 and D2 will be collectively referred to as single-sided corrugated cardboard sheet D.

[0034] The cutting device is applied to the cutoff 25. As shown in Figures 2 and 3, the cutoff 25 has a first knife cylinder 50. The first knife cylinder 50 has an upper knife cylinder 51 and a lower knife cylinder 52. The upper knife cylinder 51 and the lower knife cylinder 52 are positioned on the frame 53 along the width direction (Y direction) intersecting the transport direction (X direction) of the double-sided corrugated cardboard sheets E and F, and facing each other in the vertical direction (Z direction).

[0035] The upper knife cylinder 51 is supported at each end by bearings 54 so as to be rotatable about the axis O1 in the axial direction. The lower knife cylinder 52 is supported at each end by bearings 55 so as to be rotatable about the axis O2 in the axial direction. The upper knife cylinder 51 has a cylindrical shape, and an upper blade 51a is mounted on its outer circumference along the axial direction. The lower knife cylinder 52 has a cylindrical shape, and a lower blade 52a is mounted on its outer circumference along the axial direction.

[0036] Furthermore, the cutoff 25 has a conveyor belt 56 on the upstream side and a conveyor belt 57 on the downstream side. The conveyor belt 56 transports continuous double-sided corrugated cardboard sheets E, and the conveyor belt 57 transports flat double-sided corrugated cardboard sheets F.

[0037] The cutoff 25 is rotatable by a drive device (not shown) which allows the upper knife cylinder 51 to rotate counterclockwise in Figure 2, and the lower knife cylinder 52 to rotate clockwise in Figure 2. When a continuous sheet of double-sided corrugated cardboard E is transported by the conveyor belt 56, the sheet is cut by the upper blade 51a and lower blade 52a of the synchronously rotating upper knife cylinder 51 and lower knife cylinder 52. The cut, plate-shaped sheet of double-sided corrugated cardboard F is then transported by the conveyor belt 57.

[0038] The first knife cylinder 50 is detachably positioned relative to the frame 53. When the first knife cylinder 50 is mounted on the frame 53, the upper knife cylinder 51 and the lower knife cylinder 52 have their respective axes O1 and O2 aligned horizontally and along the width direction (Y direction) perpendicular to the transport direction (X direction) of the double-sided corrugated cardboard sheets E and F. Therefore, the first knife cylinder 50 cuts the double-sided corrugated cardboard sheets E along the Y direction perpendicular to the X direction using the upper knife cylinder 51 and the lower knife cylinder 52.

[0039] Furthermore, as shown in Figures 2 and 4, the cutoff 25 has a second knife cylinder 50A separate from the first knife cylinder 50. The second knife cylinder 50A has an upper knife cylinder 51 and a lower knife cylinder 52. The configuration of the upper knife cylinder 51 and the lower knife cylinder 52 is substantially the same as that of the first knife cylinder 50.

[0040] The second knife cylinder 50A is detachably positioned relative to the frame 53. In other words, the cutoff 25 is interchangeable between the first knife cylinder 50 and the second knife cylinder 50A. This means that the cutoff 25 can selectively attach either the first knife cylinder 50 or the second knife cylinder 50A to the double-sided corrugated cardboard sheet E being manufactured, depending on the type.

[0041] When the second knife cylinder 50A is mounted on the frame 53, the upper knife cylinder 51 and the lower knife cylinder 52 are arranged such that their respective axes O1 and O2 are along the horizontal direction and along a direction inclined by a predetermined angle θ with respect to the width direction (Y direction) orthogonal to the conveyance direction (X direction) of the double-sided corrugated sheets E and F. Therefore, the second knife cylinder 50A cuts the double-sided corrugated sheet E along a direction inclined by a predetermined angle θ with respect to the Y direction orthogonal to the X direction by the upper knife cylinder 51 and the lower knife cylinder 52. As a result, a corrugated sheet F in the shape of a parallelogram, which is a product, is formed.

[0042] As shown in FIG. 3, the double-sided corrugated sheet E is configured by bonding a corrugated core B having a waveform between a flat front liner A and a flat back liner C. At this time, the core B has a plurality of consecutive sawtooth Ba formed at intervals in the X direction along the width direction (Y direction) orthogonal to the conveyance direction (X direction) of the double-sided corrugated sheets E and F. The first knife cylinder 50 cuts the double-sided corrugated sheet E along a first cutting line CL1 along a direction parallel to the Y direction orthogonal to the X direction, that is, along a direction along the sawtooth Ba, by the upper knife cylinder 51 and the lower knife cylinder 52.

[0043] On the other hand, as shown in FIG. 4, the second knife cylinder 50A cuts the double-sided corrugated sheet E along a second cutting line CL2 along a direction inclined by a predetermined angle θ with respect to the Y direction orthogonal to the X direction, that is, along a direction inclined by a predetermined angle θ with respect to the direction along the sawtooth Ba, by the upper knife cylinder 51 and the lower knife cylinder 52.

[0044] The first knife cylinder 50 forms a plate-shaped double-sided corrugated sheet F having a rectangular shape in plan view by cutting the double-sided corrugated sheet E along the first cutting line CL1 parallel to the sawtooth Ba by the upper knife cylinder 51 and the lower knife cylinder 52. On the other hand, the second knife cylinder 50A forms a plate-shaped double-sided corrugated sheet F having a parallelogram shape in plan view by cutting the double-sided corrugated sheet E along the second cutting line CL2 inclined by a predetermined angle θ with respect to the sawtooth Ba by the upper knife cylinder 51 and the lower knife cylinder 52.

[0045] Note that, although the cutoff 25 of the present embodiment is configured to be able to replace the first knife cylinder 50 and the second knife cylinder 50A, it is not limited to this configuration. For example, the first knife cylinder 50 and the second knife cylinder 50A may be arranged along the conveyance direction of the double-sided corrugated sheet E, and the use of the first knife cylinder 50 and the second knife cylinder 50A may be selectable. In this case, when cutting the double-sided corrugated sheet E along the first cutting line CL1 along a direction parallel to the direction along the step Ba, the first knife cylinder 50 is used, and when cutting the double-sided corrugated sheet E along the second cutting line CL2 along a direction inclined by a predetermined angle θ with respect to the direction along the step Ba, the second knife cylinder 50A is used.

[0046] FIG. 5 is a plan view showing a modification of the cutting device of the present embodiment.

[0047] As shown in FIG. 5, the cutoff 25 has a knife cylinder 50B. The knife cylinder 50B has an upper knife cylinder 51 and a lower knife cylinder 52. The configurations of the upper knife cylinder 51 and the lower knife cylinder 52 are substantially the same as those of the knife cylinders 50 and 50A.

[0048] The upper knife cylinder 51 is rotatably supported about the axis O1 by a bearing portion 54, and the lower knife cylinder 52 is rotatably supported about the axis O2 by a bearing portion 55. The upper knife cylinder 51 and the lower knife cylinder 52 can be rotated synchronously by a driving device (not shown). The upper knife cylinder 51 and the lower knife cylinder 52 are movably supported at a first position (the solid line position in FIG. 5) along the Y direction orthogonal to the X direction and at a second position (the two-dot chain line position in FIG. 5) inclined by a predetermined angle θ with respect to the Y direction orthogonal to the X direction. A driving cylinder 58 as an adjusting device can move the upper knife cylinder 51 and the lower knife cylinder 52 to the first position and the second position. However, the adjusting device is not limited to the driving cylinder 58, and a combination of a motor, a ball screw mechanism, a rack and pinion mechanism, etc. may be used.

[0049] The drive cylinder 58 is positioned on one side in the width direction perpendicular to the conveying direction of the double-sided corrugated cardboard sheets E and F, and the cylinder rod is connected to the bearing portions 54 and 55 on that side. In this case, the upper knife cylinder 51 and the lower knife cylinder 52 are supported so as to be able to rotate horizontally with the axis O3 of the bearing portions 54 and 55 on the other side as the pivot point. When the drive cylinder 58 is driven, the bearing portions 54 and 55 on one side move along the X direction around the bearing portions 54 and 55 on the other side. As a result, the upper knife cylinder 51 and the lower knife cylinder 52 rotate horizontally with the axis O3 as the pivot point.

[0050] The knife cylinder 50B moves the upper knife cylinder 51 and the lower knife cylinder 52 to a first position using the drive cylinder 58. In this state, when the upper knife cylinder 51 and the lower knife cylinder 52 are driven and rotated, the double-sided corrugated cardboard sheet E is cut along the first cutting line CL1 which is perpendicular to the X direction and follows the corrugated crest Ba. At this time, the knife cylinder 50B forms a plate-shaped double-sided corrugated cardboard sheet F which is rectangular in plan view.

[0051] Meanwhile, the knife cylinder 50B moves the upper knife cylinder 51 and the lower knife cylinder 52 to a second position using the drive cylinder 58. In this state, when the upper knife cylinder 51 and the lower knife cylinder 52 are driven and rotated, the double-sided corrugated cardboard sheet E is cut along a second cutting line CL2 that is inclined by a predetermined angle θ with respect to the Y direction which is perpendicular to the X direction, that is, inclined by a predetermined angle θ with respect to the direction along the corrugated cardboard ridge Ba. At this time, the knife cylinder 50B forms a plate-shaped double-sided corrugated cardboard sheet F that has a parallelogram shape in plan view.

[0052] Figure 6 is a schematic diagram illustrating the adjustment angle of the cutting device.

[0053] As shown in Figure 6, the second cutting line CL2 for forming a plate-shaped double-sided corrugated cardboard sheet F that has a parallelogram shape in plan view is inclined by a predetermined angle θ with respect to the Y direction which is perpendicular to the X direction, that is, inclined by a predetermined angle θ with respect to the direction along the corrugation Ba. In this case, the second cutting line CL2 is inclined by a predetermined angle θ with respect to the direction along the corrugation Ba so as to straddle at least one corrugation Ba. Specifically, the second cutting line CL2 is along the direction that diagonally connects one end position W1 and the other end position W2 in the width direction (Y direction) of the double-sided corrugated cardboard sheet E(F). The one end position W1 and the other end position W2 are a pair of positions that are offset by one pitch or more of the corrugation Ba along the transport direction (X direction) of the double-sided corrugated cardboard sheet E(F). In this case, the predetermined angle θ is the angle at which the second cutting line CL2 becomes a cutting line that straddles one pitch or more of the corrugation Ba.

[0054] In a double-sided corrugated cardboard sheet E, a corrugated core B is located between the front liner A and the back liner C. The core B has multiple corrugations Ba formed in the X direction. Furthermore, the corrugations Ba are formed alternately, some protruding towards the front liner A and others towards the back liner C. One pitch of corrugations Ba is the distance between the tops Ba1 of a pair of adjacent corrugations Ba protruding towards the front liner A, or the distance between the tops Ba1 of a pair of adjacent corrugations Ba protruding towards the back liner C, in the transport direction (X direction) of the double-sided corrugated cardboard sheet E(F).

[0055] In the explanation of Figures 4 to 6, the upper knife cylinder 51 and the lower knife cylinder 52 are positioned at a second position inclined by a predetermined angle θ with respect to the Y direction perpendicular to the X direction, by positioning one end in the Y direction forward in the conveying direction with the other end in the Y direction as a pivot point, relative to a first position along the Y direction perpendicular to the X direction. In this case, the upper knife cylinder 51 and the lower knife cylinder 52 may also be positioned at a second position inclined by a predetermined angle θ with respect to the Y direction perpendicular to the X direction, by positioning one end in the Y direction backward in the conveying direction with the other end in the Y direction as a pivot point. Alternatively, the upper knife cylinder 51 and the lower knife cylinder 52 may also be positioned at a second position inclined by a predetermined angle θ with respect to the Y direction perpendicular to the X direction, by positioning one end in the Y direction forward or backward in the conveying direction with the other end in the Y direction as a pivot point.

[0056] <Reduction Gear> Figure 7 is a side view of the reduction gear. Figure 8 is a top view of the reduction gear.

[0057] As shown in Figures 1, 7, and 8, a reduction gear 60 is provided downstream of the cutoff 25 in the transport direction (X direction) of the double-sided corrugated cardboard sheet E. The reduction gear 60 is positioned between the cutoff 25 and the defective product discharge device 26. The reduction gear 60 slows down the good double-sided corrugated cardboard sheet F formed from the cutoff 25, which will become the final product, thereby overlapping a portion of the double-sided corrugated cardboard sheet F.

[0058] Downstream of the cutoff 25, conveyor belts 61 and 62 are arranged in series in the direction of transport (X direction) of the double-sided corrugated cardboard sheet F. The reduction device 60 has a plurality of reduction brushes (reduction members) 63, 64, and 65. The reduction brushes 63, 64, and 65 have substantially the same configuration and are arranged with gaps in the X direction.

[0059] The reduction brushes 63, 64, and 65 are arranged along the Y direction, their base ends supported by a frame (not shown), and their tips extending downstream in the conveying direction (X direction) of the double-sided corrugated cardboard sheet F. The tips of the reduction brushes 63, 64, and 65 extend towards the upper surface of the conveying conveyors 61 and 62 and contact the upper surface of the double-sided corrugated cardboard sheet F moving on the conveying conveyors 61 and 62. The reduction brushes 63, 64, and 65 are supported so as to be movable between a first position (solid line position in Figure 8) along the Y direction perpendicular to the X direction and a second position (dotted line position in Figure 8) inclined by a predetermined angle θ with respect to the Y direction perpendicular to the X direction. The drive cylinder 66, acting as an adjustment device, can move the reduction brushes 63, 64, and 65 between the first and second positions. However, the adjustment device is not limited to the drive cylinder 66.

[0060] The reduction brushes 63, 64, and 65 are supported at their respective ends in the Y direction by support portions 67. The drive cylinder 66 is positioned on one side in the Y direction, and its cylinder rod is connected to the support portion 67 on that side. In this case, the reduction brushes 63, 64, and 65 are supported so as to be able to rotate horizontally with the axis O4 of the support portion 67 on the other side as the pivot point. When the drive cylinder 66 is driven, the support portion 67 on one side moves along the X direction around the support portion 67 on the other side. As a result, the reduction brushes 63, 64, and 65 rotate horizontally with the axis O4 as the pivot point.

[0061] The reduction gear 60 operates in conjunction with the cutoff 25. That is, the reduction brushes 63, 64, and 65 of the reduction gear 60 operate in accordance with the upper knife cylinder 51 and lower knife cylinder 52 of the cutoff 25. When the upper knife cylinder 51 and lower knife cylinder 52 of the cutoff 25 are in a first position along the Y direction perpendicular to the X direction, the reduction brushes 63, 64, and 65 of the reduction gear 60 are also in a first position along the Y direction perpendicular to the X direction. Then, when the upper knife cylinder 51 and lower knife cylinder 52 of the cutoff 25 are in a second position tilted by a predetermined angle θ with respect to the Y direction perpendicular to the X direction, the reduction brushes 63, 64, and 65 of the reduction gear 60 are also in a second position tilted by a predetermined angle θ with respect to the Y direction perpendicular to the X direction. That is, the reduction brushes 63, 64, and 65 of the reduction gear 60 are positioned at the same angle as the upper knife cylinder 51 and lower knife cylinder 52 of the cutoff 25. However, the angles of the reduction brushes 63, 64, and 65 of the reduction gear 60 and the angles of the upper knife cylinder 51 and lower knife cylinder 52 of the cutoff 25 do not have to be the same. In other words, the reduction brushes 63, 64, and 65 only need to be tilted in the same direction as the direction of tilting by a predetermined angle θ; that is, even if the angles are different, it is sufficient if the direction of tilting is the same.

[0062] Furthermore, the reduction brushes 63, 64, and 65 of the reduction gear 60 may be made replaceable, similar to the knife cylinders 50 and 50A of the cutoff 25.

[0063] When a double-sided corrugated cardboard sheet F moves along the conveyor belts 61 and 62, the tips of the reduction brushes 63, 64, and 65 come into contact with the upper surface and are pushed down, causing it to slow down. As a result, the leading edge of a subsequent double-sided corrugated cardboard sheet F is superimposed on the trailing edge of the double-sided corrugated cardboard sheet F that has been slowed down by the reduction brushes 63, 64, and 65. In this case, if the double-sided corrugated cardboard sheet F is in the shape of a parallelogram, the reduction brushes 63, 64, and 65 are tilted to match the cutting line of the double-sided corrugated cardboard sheet F. As a result, the reduction brushes 63, 64, and 65 are constantly in contact with the double-sided corrugated cardboard sheet F over its entire Y-direction. Therefore, the double-sided corrugated cardboard sheet F is prevented from bending during transport and can be appropriately slowed down.

[0064] <Conveying device and stopping device> Figure 9 is a side view showing the conveying device and the stopping device.

[0065] As shown in Figures 1 and 9, a conveying device 70 and a stopping device 80 are provided downstream of the cutoff 25 in the conveying direction (X direction) of the double-sided corrugated cardboard sheets E. The conveying device 70 and the stopping device 80 are positioned between the defective product discharge device 26 and the stacker 27. The conveying device 70 supplies the double-sided corrugated cardboard sheets F, which are formed from the cutoff 25 and stacked by the reduction device 60, to the stacker 27. The stopping device 80 stacks the double-sided corrugated cardboard sheets F supplied by the conveying device 70 to a predetermined position and stops them.

[0066] The conveying device 70 has a nip roll 71 and a receiving roll 72 as conveying rolls. The nip roll 71 and the receiving roll 72 are arranged to be aligned along the Y direction and to be opposed to each other vertically. The nip roll 71 is rotatable by a drive device (not shown). The receiving roll 72 is in contact with the nip roll 71 and can rotate in accordance with it, but may also be rotatable by a drive device. The double-sided corrugated cardboard sheet F is supplied between the nip roll 71 and the receiving roll 72 by a conveying conveyor 73. The nip roll 71 and the receiving roll 72 rotate while gripping the double-sided corrugated cardboard sheet F, thereby conveying it toward the stacker 27 at a predetermined speed.

[0067] The stopping device 80 includes a support base 81 and a stopper 82. The stopper 82 is positioned on the support base 81. The double-sided corrugated cardboard sheets F are transported at a predetermined speed while being held between the nip roll 71 and the receiving roll 72, and are stopped when their leading edges come into contact with the stopper 82, and are stacked in a predetermined position on the support base 81.

[0068] The nip roll 71 and receiving roll 72 of the conveying device 70 are movable between a first position and a second position by a drive cylinder 74 acting as an adjustment device, similar to the reduction brushes 63, 64, and 65 of the reduction device 60. Similarly, the stopper 82 of the stopping device 80 is movable between a first position and a second position by a drive cylinder 83 acting as an adjustment device, similar to the reduction brushes 63, 64, and 65 of the reduction device 60. Here, the first position is where the nip roll 71 and receiving roll 72 and the stopper 82 are aligned along the Y direction perpendicular to the X direction. The second position is where the nip roll 71 and receiving roll 72 and the stopper 82 are inclined by a predetermined angle θ with respect to the Y direction perpendicular to the X direction. However, the angles of the nip roll 71 and receiving roll 72 of the conveying device 70 and the stopper 82 of the stopping device 80 do not have to be the same as the angles of the upper knife cylinder 51 and lower knife cylinder 52 of the cutoff 25. In other words, the conveying device 70 and the stopping device 80 must be in the same direction as the direction in which they tilt by a predetermined angle θ; that is, even if the angles are different, it is sufficient if the direction of tilting is the same.

[0069] The adjustment method for the nip roll 71, receiving roll 72, and stopper 82 is the same as for the reduction gear 60, and therefore the explanation is omitted.

[0070] <Control System of Corrugated Machine> Figure 10 is a block diagram showing the control system of a corrugated machine.

[0071] As shown in Figure 10, in the corrugated machine 10, the mill roll stands 11, 12, 15, 16, 19, single facers 13, 17, bridges 14, 18, preheater 20, glue machine 21, double facer 22, rotary shear 23, slitter scorer 24, cutoff 25, defective product discharge device 26, and stacker 27 are connected to control devices 91. Specifically, the cutoff 25 is connected to a cutoff control device 91a, and the stacker 27 is connected to a stacker control device 91b. The cutoff control device 91a controls the operation of the cutoff 25, and the stacker control device 91b controls the operation of the stacker 27. Although not shown in the diagram, the mill roll stands 11, 12, 15, 16, 19, single facers 13, 17, bridges 14, 18, preheater 20, glue machine 21, double facer 22, rotary slicer 23, slitter scorer 24, and defective product discharge device 26 are each connected to their own individual control devices. The control device 91 (control devices 91a, 91b) is connected to the production management device 92, and production management information for corrugated cardboard sheets is input to it. Based on the production management information, the control device 91 controls the mill roll stands 11, 12, 15, 16, 19, single facers 13, 17, bridges 14, 18, preheater 20, glue machine 21, double facer 22, rotary slicer 23, slitter scorer 24, cutoff 25, defective product discharge device 26, and stacker 27.

[0072] Production management information includes the shape of the corrugated cardboard sheet, the cutting width, the cutting length, and the cutting angle of the corrugated cardboard sheet. Therefore, the control device 91 (cutoff control device 91a) adjusts the angles of the upper knife cylinder 51 and the lower knife cylinder 52 at the cutoff 25 based on the cutting angle of the corrugated cardboard sheet. For example, as shown in Figure 5, if the cutoff 25 has a knife cylinder 50B, the control device 91 adjusts the angles of the upper knife cylinder 51 and the lower knife cylinder 52 by operating the drive cylinder 58 based on the cutting angle of the corrugated cardboard sheet. In this case, the control device 91 adjusts the angles of the upper knife cylinder 51 and the lower knife cylinder 52 by the amount of extension and retraction of the drive cylinder 58, that is, the amount of movement of the bearing parts 54 and 55.

[0073] The production management device 92 determines the cutting angle based on the shape and cutting width of the corrugated cardboard sheet as production management information, transmits the cutting angle to the cutoff control device 91a, and the cutoff control device 91a operates the drive cylinder 58 to adjust the angle of the knife cylinder 50B. However, the production management device 92 may also transmit the shape and cutting width of the corrugated cardboard sheet as production management information to the cutoff control device 91a, and the cutoff control device 91a may determine the cutting angle based on the shape and cutting width of the corrugated cardboard sheet and operate the drive cylinder 58 to adjust the angle of the knife cylinder 50B.

[0074] Furthermore, the production management device 92 determines the cutting angle based on the shape and cutting width of the corrugated cardboard sheet as production management information, transmits the cutting angle to the stacker control device 91b, and the stacker control device 91b operates the drive cylinder 66 to adjust the angles of the reduction brushes 63, 64, and 65. However, the production management device 92 may also transmit the shape and cutting width of the corrugated cardboard sheet as production management information to the stacker control device 91b, and the stacker control device 91b may determine the cutting angle based on the shape and cutting width of the corrugated cardboard sheet and operate the drive cylinder 66 to adjust the angles of the reduction brushes 63, 64, and 65.

[0075] The control method for the nip roll 71, receiving roll 72, and stopper 82 is the same as that for the reduction gear 60.

[0076] Now, let's explain the cutting angle. Figure 11 is an explanatory diagram of the cutting angle based on the pitch.

[0077] The cutting angle is an angle inclined by a predetermined angle θ with respect to the width direction of the corrugated cardboard sheet so as to straddle at least one ridge Ba. The cutting angle (predetermined angle θ) is determined by the production control device 92 based on at least the form of the corrugated cardboard sheet and the cutting width. One form of corrugated cardboard sheet is the flute, and the pitch of the ridges Ba differs depending on the type. As shown in Figure 11, for example, the pitch of the ridges Ba in A flute is larger than that of B flute. In this case, the cutting angle θ1 for A flute is set to be larger than the cutting angle θ2 for B flute. Since the pitch of the ridges Ba is larger in A flute compared to B flute, setting a larger cutting angle results in the second cutting line CL2 becoming a cutting line that straddles one or more ridges Ba.

[0078] Figure 12 is an explanatory diagram of the cutting angle based on the cutting width.

[0079] As shown in Figure 12, the corrugated cardboard sheet is cut in the X direction by the slitter scorer 24 to a predetermined cutting width. In this case, for example, when cutting the corrugated cardboard sheet to a predetermined cutting width using two pieces versus using three pieces, the cutting width is narrower when using three pieces than when using two pieces. In this case, the cutting angle θ3 for the narrower cutting width of the three pieces is set to be larger than the cutting angle θ4 for the wider cutting width of the two pieces. Because the cutting width is narrower when using three pieces than when using two pieces, by setting a larger cutting angle, the second cutting line CL2 becomes a cutting line that crosses the corrugated cardboard peaks Ba by one pitch or more.

[0080] Alternatively, the optimal cutting angle based on the shape and cutting width of the corrugated cardboard sheet may be determined in advance through experiments, etc., and stored in the production management device 92, and set when the production conditions for the corresponding corrugated cardboard sheet are met. Alternatively, the cutting angle may be calculated using a predetermined function. Furthermore, the cutting angle may be updated through teaching. Additionally, the cutting angle may be input into the production management device 92 based on the operator's experience and set accordingly.

[0081] Furthermore, the production control device 92 may individually determine the angles of the reduction brushes 63, 64, and 65, the conveying device 70, and the stopping device 80 based on the shape and cutting width of the corrugated cardboard sheet, similar to the cutting angle. In other words, the angles of the reduction brushes 63, 64, and 65, the conveying device 70, and the stopping device 80 may be different angles or the same angle. The angles of the reduction brushes 63, 64, and 65, the conveying device 70, and the stopping device 80 may be determined in advance through experiments or other means based on the shape and cutting width of the corrugated cardboard sheet, stored in the production control device 92, and set when the production conditions for the corresponding corrugated cardboard sheet are met. Alternatively, each angle may be calculated using a predetermined function. Alternatively, each angle may be updated by teaching. Alternatively, each angle may be input into the production control device 92 based on the operator's experience and set.

[0082] <Modified arrangement of knife cylinders> Figure 13 is a side view showing a first modified arrangement of knife cylinders in a cutting device.

[0083] As shown in Figure 13, the cutoff 25 has a first knife cylinder 50 and a second knife cylinder 50A. The first knife cylinder 50 cuts the corrugated cardboard sheet E along the direction along the corrugation Ba. The second knife cylinder 50A cuts the corrugated cardboard sheet E along a direction inclined by a predetermined angle θ with respect to the direction along the corrugation Ba. The first knife cylinder 50 and the second knife cylinder 50A have the same configuration as described above, so their explanation is omitted.

[0084] The first knife cylinder 50 and the second knife cylinder 50A are arranged in series along the conveying direction of the corrugated cardboard sheets D and E. In this case, the first knife cylinder 50 is positioned upstream and the second knife cylinder 50A is positioned downstream with respect to the conveying direction of the corrugated cardboard sheets D and E. However, the second knife cylinder 50A may be positioned upstream and the first knife cylinder 50 may be positioned downstream with respect to the conveying direction of the corrugated cardboard sheets D and E. Alternatively, a knife cylinder 50B may be used instead of the second knife cylinder 50A.

[0085] Figure 14 is a side view showing a second modified example of the arrangement of the knife cylinder in the cutting device.

[0086] As shown in Figure 14, the corrugated machine 10 is equipped with a web director (director device) 28. The web director 28 is located upstream of the cutoff 25 and sorts the two types of corrugated cardboard sheets E1 and E2 cut by the slitter scorer 24 into upper and lower sections. The web director 28 has a large number of slats in the width direction of the corrugated cardboard sheets E1 and E2, and by swinging each slat up and down, it transports, for example, corrugated cardboard sheet E1 to the upper transport line LA and corrugated cardboard sheet E2 to the lower transport line LB.

[0087] The cutoff 25 includes a first knife cylinder 50 and a knife cylinder 50B. The first knife cylinder 50 is located on the upper transport line LA, and the knife cylinder 50B is located on the lower transport line LB. The first knife cylinder 50 cuts the corrugated cardboard sheet E1 along the direction of the corrugation ridge Ba. The knife cylinder 50B can cut the corrugated cardboard sheet E2 along a direction inclined by a predetermined angle θ with respect to the direction of the corrugation ridge Ba, and the cutting angle is adjustable. In this case, two types of corrugated cardboard sheets F1 and F2 (rectangle and parallelogram) can be manufactured simultaneously.

[0088] However, the first knife cylinder 50 may be placed on the lower conveying line and the knife cylinder 50B on the upper conveying line. Alternatively, the second knife cylinder 50A may be placed in place of the knife cylinder 50B.

[0089] Figure 15 is a side view showing a third modified example of the arrangement of the knife cylinder in the cutting device.

[0090] As shown in Figure 15, the corrugated machine 10 is equipped with a web director 28. The cutoff 25 has two first knife cylinders 50 and two second knife cylinders 50A. The upper transport line LA is equipped with the first knife cylinders 50 and the second knife cylinders 50A, and the lower transport line LB is equipped with the first knife cylinders 50 and the second knife cylinders 50A. In the upper transport line LA, either the first knife cylinders 50 or the second knife cylinders 50A are operated, and in the lower transport line LB, either the first knife cylinders 50 or the second knife cylinders 50A are operated. In this case, corrugated cardboard sheets F1 and F2 of the same type (rectangle or parallelogram) can be manufactured. Alternatively, two types of corrugated cardboard sheets F1 and F2 (rectangle and parallelogram) can be manufactured simultaneously.

[0091] However, the second knife cylinder 50A may be positioned upstream of the corrugated cardboard sheets D and E in the transport direction, and the first knife cylinder 50 may be positioned downstream. Alternatively, a knife cylinder 50B may be positioned instead of the second knife cylinder 50A.

[0092] Figure 16 is a side view showing a fourth modified example of the arrangement of the knife cylinder in the cutting device.

[0093] As shown in Figure 16, the corrugating machine 10 is equipped with a web director 28. The cutoff 25 has two knife cylinders 50B. The knife cylinders 50B are arranged on the upper transport line LA and the lower transport line LB, respectively. In this case, corrugated cardboard sheets F1 and F2 of the same type (rectangle or parallelogram) can be manufactured. Alternatively, two types of corrugated cardboard sheets F1 and F2 (rectangle and parallelogram) can be manufactured simultaneously. Furthermore, two types of corrugated cardboard sheets F1 and F2 with different inclination angles (parallelogram) can be manufactured simultaneously.

[0094] Furthermore, the reduction gear 60, conveying device 70, and stopping device 80 described above are also provided in the four types of modifications mentioned above.

[0095] <Corrugated cardboard sheet> Figure 17 is a plan view showing the double-sided corrugated cardboard sheet of this embodiment.

[0096] As shown in Figures 1 and 17, a continuous double-sided corrugated cardboard sheet E is formed by laminating a corrugated core B between the front liner A and the back liner C. When the front and back ends in the transport direction (X direction) are cut along the second cutting line CL2, a plate-shaped double-sided corrugated cardboard sheet F is formed, which has a parallelogram shape in plan view. In the double-sided corrugated cardboard sheet F, two opposing first sides 101 and 102 are perpendicular to the direction along the corrugation Ba, and two opposing second sides 103 and 104 are inclined by a predetermined angle θ with respect to the direction along the corrugation Ba.

[0097] The double-sided corrugated cardboard sheet F has corrugated ridges Ba of the core B along the width direction (Y direction). The double-sided corrugated cardboard sheet F is cut along the X direction by a slitter scorer 24 so that both sides in the width direction (Y direction) have a predetermined width, so the first two sides 101 and 102 on both sides in the width direction (Y direction) are perpendicular to the direction along the corrugated ridges Ba. In addition, the double-sided corrugated cardboard sheet F is cut along a second cutting line CL2 that is inclined by a predetermined angle θ from the Y direction so that the front and rear in the transport direction (X direction) have a predetermined length by a cutoff 25, so the second two sides 103 and 104 on the front and rear in the transport width direction (X direction) are inclined by a predetermined angle θ with respect to the direction along the corrugated ridges Ba.

[0098] Figure 18 is a plan view showing a double-sided corrugated cardboard sheet after die-cutting, and Figure 19 is a plan view showing a single-sided corrugated cardboard sheet after die-cutting. The double-sided corrugated cardboard sheet F shown in Figures 18 and 19 is a parallelogram in which two opposing second sides 103 and 104 are inclined by a predetermined angle θ with respect to the direction along the corrugation ridge Ba. However, in order to clearly explain that the double-sided corrugated cardboard sheet F is a parallelogram, the predetermined angle θ is shown as larger. The predetermined angle θ only needs to be set so that the second cutting line CL2 is a cutting line that crosses at least one corrugation ridge Ba.

[0099] As shown in Figure 17, a sheet of double-sided corrugated cardboard F is die-cut using a press machine (not shown) to form creases and glue tabs. The double-sided corrugated cardboard sheet F is a so-called blank sheet, without creases or glue tabs. The double-sided corrugated cardboard sheet F, as a blank sheet, is die-cut to create creases and glue tabs.

[0100] As shown in Figure 18, the double-sided corrugated cardboard sheet F after die-cutting has four first creases 111 and 112 along a direction perpendicular to the second two sides 103 and 104, and two second creases 113 and 114 along a direction parallel to the second two sides 103 and 104. In addition, the double-sided corrugated cardboard sheet F after die-cutting has adhesive tabs 121 and 122 extending in a direction perpendicular to the second two sides 103 and 104. Note that in Figure 18, the white areas on the second two sides 103 and 104 side of the double-sided corrugated cardboard sheet F are the areas that are die-cut and discarded.

[0101] A double-sided corrugated cardboard sheet F, which has first creases 111, 112 and second creases 113, 114 and adhesive tabs 121, 122, is folded at the positions of the first creases 111, 112 and the second creases 113, 114, and then the adhesive tabs 121, 122 are overlapped and glued together to form a corrugated cardboard box. At this time, since the first creases 111, 112 and the second creases 113, 114 are provided so as to diagonally straddle at least one corrugated ridge, the sheet is properly folded at the positions of the first creases 111, 112 and the second creases 113, 114.

[0102] Furthermore, the corrugated cardboard box is shaped like a rectangular prism, with the positions of the folded first creases 111, 112 and the second creases 113, 114 becoming the sides of the rectangular prism. The corrugated cardboard box has corrugated ridges Ba of the core B that are inclined at a predetermined angle θ with respect to each side. As a result, the corrugated cardboard box has sufficient strength against vertical and horizontal stresses.

[0103] Up to this point, a continuous double-sided corrugated cardboard sheet E has been cut with a cut-off 25 to form a plate-shaped double-sided corrugated cardboard sheet F, and a corrugated cardboard box has been formed by creating creases and glue tabs on the plate-shaped double-sided corrugated cardboard sheet F. In this case, a continuous single-sided corrugated cardboard sheet D may also be cut with a cut-off 25 to form a plate-shaped single-sided corrugated cardboard sheet, and a corrugated cardboard box may be formed by creating creases and glue tabs on the plate-shaped single-sided corrugated cardboard sheet.

[0104] In the above explanation, a continuous double-sided corrugated cardboard sheet E is cut by a cut-off 25 to form a plate-shaped double-sided corrugated cardboard sheet F, and then the plate-shaped double-sided corrugated cardboard sheet F is punched out to form creases and glue tabs, thereby enabling the formation of a corrugated cardboard box. However, the configuration is not limited to this.

[0105] As shown in Figures 1 and 19, a continuous single-sided corrugated cardboard sheet D (D1, D2) can be cut with a cut-off 25 to form a plate-shaped single-sided corrugated cardboard sheet G, and by punching out the plate-shaped single-sided corrugated cardboard sheet G, creases and adhesive edges can be formed to create an envelope.

[0106] In other words, the die-cut single-sided corrugated cardboard sheet G has two first creases 111 and 112 along a direction perpendicular to the second two sides 103 and 104, and two second creases 113 and 114 along a direction parallel to the second two sides 103 and 104. In addition, the die-cut single-sided corrugated cardboard sheet G has adhesive tabs 121 and 122 extending in a direction perpendicular to the second two sides 103 and 104. In Figure 19, the white areas on the second two sides 103 and 104 of the single-sided corrugated cardboard sheet G are the areas that are die-cut and discarded.

[0107] A single-sided corrugated cardboard sheet G, which has first creases 111, 112 and second creases 113, 114 and adhesive tabs 121, 122, is folded at the positions of the first creases 111, 112 and the second creases 113, 114, and then the adhesive tabs 121, 122 are overlapped and glued together to form an envelope. At this time, since the first creases 111, 112 and the second creases 113, 114 are provided so as to diagonally straddle at least one corrugated ridge, the sheet is properly folded at the positions of the first creases 111, 112 and the second creases 113, 114.

[0108] Furthermore, the envelope's edges are determined by the positions of the folded first creases 111, 112 and the second creases 113, 114. The envelope has a stepped core B with a raised edge Ba that is inclined at a predetermined angle θ with respect to each edge. As a result, the envelope has sufficient strength against in-plane stress.

[0109] In this example, an envelope is formed by creating creases and adhesive tabs on a flat, single-sided corrugated cardboard sheet G. Alternatively, an envelope may be formed by creating creases and adhesive tabs on a flat, double-sided corrugated cardboard sheet F.

[0110] [Effects of this embodiment] The cutting device according to the first embodiment is a cutoff (cutting device) 25 that cuts corrugated cardboard sheets D and E formed by bonding together at least one flat liner A and C and a core B having a plurality of corrugated ridges Ba, and cuts the corrugated cardboard sheets D and E into parallelograms along a second cutting line CL2 that is inclined by a predetermined angle θ with respect to the direction along the corrugated ridges Ba.

[0111] According to the cutting device of the first embodiment, when continuous corrugated cardboard sheets D and E are cut along a second cutting line CL2 that is inclined by a predetermined angle θ, parallelogram-shaped corrugated cardboard sheets F and G are formed. Therefore, when the parallelogram-shaped corrugated cardboard sheets F and G are folded along the first creases 111, 112 and the second creases 113, 114 to form boxes and envelopes as corrugated cardboard products, the fold lines will diagonally cross at least one corrugated ridge, allowing for proper folding at the positions of the first creases 111, 112 and the second creases 113, 114. Furthermore, in the corrugated cardboard box formed by folding the corrugated cardboard sheets F and G, the corrugated ridges Ba of the core B are positioned at an angle θ with respect to each side, ensuring sufficient strength against vertical and horizontal stresses. As a result, both folding accuracy and strength can be improved. Furthermore, it is possible to reduce the amount of waste generated when processing grooves and adhesive tabs on corrugated cardboard sheets F and G.

[0112] The cutting device according to the second embodiment is the cutting device according to the first embodiment, further comprising: a core B having multiple corrugated ridges Ba formed at intervals in the transport direction of the corrugated cardboard sheets D and E along the width direction perpendicular to the transport direction of the corrugated cardboard sheets D and E; and the second cutting line CL2 is aligned in a direction inclined by a predetermined angle θ with respect to the width direction of the corrugated cardboard sheets D and E so as to straddle at least one corrugated ridge Ba. This improves both the bending accuracy and the strength. Furthermore, it reduces the area of ​​waste when processing grooves and adhesive strips on the corrugated cardboard sheets F and G.

[0113] The cutting device according to the third embodiment is a cutting device according to the first or second embodiment, further comprising a first knife cylinder 50 for cutting corrugated cardboard sheets D and E along a direction along the corrugation Ba, and a second knife cylinder 50A for cutting corrugated cardboard sheets D and E along a direction inclined by a predetermined angle θ with respect to the direction along the corrugation Ba, and the use of at least one of the first knife cylinder 50 and the second knife cylinder 50A can be selected. As a result, rectangular corrugated cardboard sheets F and G can be formed with the first knife cylinder 50, and parallelogram-shaped corrugated cardboard sheets F and G can be formed with the second knife cylinder 50A.

[0114] The cutting device according to the fourth embodiment is a cutting device according to any one of the first to third embodiments, and further includes a knife cylinder 50B for cutting corrugated cardboard sheets D and E, and a drive cylinder (adjustment device) 58 for adjusting the upper knife cylinder 51 and the lower knife cylinder 52 to a first position in the direction along the corrugation Ba and a second position in the direction inclined by a predetermined angle θ with respect to the direction along the corrugation Ba. As a result, rectangular corrugated cardboard sheets F and G and parallelogram-shaped corrugated cardboard sheets F and G can be formed with a single knife cylinder 50B.

[0115] The fifth embodiment of the cutting apparatus is a cutting apparatus according to the fourth embodiment, further comprising a production management device 92 having production management information for corrugated cardboard sheets D and E, and a control device 91 to which production management information is input from the production management device 92, the control device 91 controlling the drive cylinder 58 based on the production management information. As a result, corrugated cardboard sheets F and G of the desired shape can be automatically formed based on the production management information.

[0116] The cutting device according to the sixth embodiment is a cutting device according to the fifth embodiment, wherein the production management device 92 further determines a cutting angle that is inclined by a predetermined angle with respect to the width direction of the corrugated cardboard sheets D and E, based on the shape and cutting width of the corrugated cardboard sheets D and E, so as to straddle at least one corrugated ridge Ba. This makes it possible to cut with an optimal cutting angle based on the shape and cutting width of the corrugated cardboard sheets D and E, thereby improving bending accuracy and strength.

[0117] The cutting device according to the seventh embodiment is a cutting device according to the fifth embodiment, wherein the control device 91 further determines a cutting angle that is inclined by a predetermined angle with respect to the width direction of the corrugated cardboard sheets D and E, based on the shape and cutting width of the corrugated cardboard sheets D and E, so as to straddle at least one of the corrugated cardboard ridges Ba. This makes it possible to cut with an optimal cutting angle based on the shape and cutting width of the corrugated cardboard sheets D and E, thereby improving bending accuracy and strength.

[0118] A method for manufacturing corrugated cardboard sheets according to the eighth embodiment is a method for manufacturing corrugated cardboard sheets D and E which are formed by bonding at least one flat liner A and C with a core B having a plurality of corrugated ridges Ba, wherein the corrugated cardboard sheets D and E are cut into parallelograms along a second cutting line CL2 which is inclined by a predetermined angle θ with respect to the direction along the corrugated ridges Ba.

[0119] According to the eighth embodiment of the method for manufacturing corrugated cardboard sheets, when continuous corrugated cardboard sheets D and E are cut along a second cutting line CL2 that is inclined by a predetermined angle θ, parallelogram-shaped corrugated cardboard sheets F and G are formed. Therefore, when the corrugated cardboard sheets F and G are folded with first creases 111, 112 and second creases 113, 114, the fold lines will diagonally cross at least one corrugated ridge, allowing for proper folding at the positions of the first creases 111, 112 and the second creases 113, 114. Furthermore, in the corrugated cardboard box formed by folding the corrugated cardboard sheets F and G, the corrugated ridges Ba of the core B are positioned at an inclination of a predetermined angle θ with respect to each side, ensuring sufficient strength against vertical and horizontal stresses. As a result, folding accuracy can be improved, and strength can be enhanced. In addition, the area of ​​waste when processing grooves and adhesive tabs on the corrugated cardboard sheets F and G can be reduced.

[0120] The method for manufacturing corrugated cardboard sheets according to the ninth embodiment is the method for manufacturing corrugated cardboard sheets according to the eighth embodiment, further comprising die-cutting the corrugated cardboard sheets D and E, which have been cut into parallelograms, to form first creases 111 and 112, second creases 113 and 114, and adhesive tabs 121 and 122. This makes it possible to appropriately form corrugated cardboard sheets F and G having the first creases 111 and 112, second creases 113 and 114, and adhesive tabs 121 and 122. In addition, it is possible to reduce the area that is discarded when processing grooves and adhesive tabs on corrugated cardboard sheets F and G.

[0121] The corrugated cardboard sheet manufacturing apparatus according to the tenth embodiment includes single facers 13, 17 and double facer 22 (sheet laminating apparatus) that form corrugated cardboard sheets D, E by laminating at least one flat liner A, C and a core B having a plurality of corrugated ridges Ba in a wave shape, and a cut-off (cutting apparatus) 25 for cutting the corrugated cardboard sheets D, E. This makes it possible to improve the bending accuracy of the corrugated cardboard sheets F, G and to improve their strength. In addition, it is possible to reduce the area of ​​waste when processing grooves and adhesive edges on the corrugated cardboard sheets F, G.

[0122] The corrugated cardboard sheet manufacturing apparatus according to the 11th embodiment is a corrugated cardboard sheet manufacturing apparatus according to the 10th embodiment, further comprising a reduction device 60 arranged downstream of the cutoff 25 in the conveying direction of the corrugated cardboard sheets D and E, which reduces the corrugated cardboard sheets D and E by bringing a reduction brush (reduction member) 63 into contact with the upper surface of the corrugated cardboard sheets D and E, and the reduction brush 63 is provided along the same direction as the direction of inclination by a predetermined angle θ. As a result, the corrugated cardboard sheets F and G, which form parallelograms, can be appropriately reduced in speed without bending in the conveying direction.

[0123] The corrugated cardboard sheet manufacturing apparatus according to the twelfth embodiment is a corrugated cardboard sheet manufacturing apparatus according to the eleventh embodiment, further comprising a drive cylinder 66 as an adjustment device for adjusting the reduction brushes 63, 64, and 65 to a first position in the direction along the corrugation Ba and a second position in the same direction as the direction inclined by a predetermined angle θ with respect to the direction along the corrugation Ba. This allows the reduction brushes 63, 64, and 65 to be adjusted to appropriate positions by the drive cylinder 66.

[0124] The corrugated cardboard sheet manufacturing apparatus according to the 13th embodiment is a corrugated cardboard sheet manufacturing apparatus according to any one of the 10th to 12th embodiments, further comprising a conveying device 70 arranged downstream of the cutoff 25 in the conveying direction of the corrugated cardboard sheets D and E, which conveys the corrugated cardboard sheets D and E by bringing a nip roll (conveying roll) 71 and a receiving roll (conveying roll) 72 into contact with the corrugated cardboard sheets D and E, and the nip roll 71 and the receiving roll 72 are provided along the same direction as the direction in which they are inclined by a predetermined angle θ. As a result, the corrugated cardboard sheets F and G, which form parallelograms, can be conveyed appropriately without bending in the conveying direction.

[0125] The corrugated cardboard sheet manufacturing apparatus according to the 14th embodiment is a corrugated cardboard sheet manufacturing apparatus according to the 13th embodiment, further comprising a drive cylinder 74 as an adjustment device for adjusting the nip roll 71 and the receiving roll 72 to a first position in the direction along the corrugation crest Ba and a second position in the same direction as the direction inclined by a predetermined angle θ with respect to the direction along the corrugation crest Ba. This allows the nip roll 71 and the receiving roll 72 to be adjusted to appropriate positions by the drive cylinder 74.

[0126] The corrugated cardboard sheet manufacturing apparatus according to the 15th embodiment is a corrugated cardboard sheet manufacturing apparatus according to the 13th or 14th embodiment, further comprising a stopping device 80 arranged downstream of the conveying device 70 in the conveying direction of the corrugated cardboard sheets D and E, which stops the corrugated cardboard sheets D and E by bringing the downstream ends of the corrugated cardboard sheets D and E in the conveying direction into contact with a stopper 82, and the stopper 82 is provided along the same direction as the direction of inclination by a predetermined angle θ. As a result, the corrugated cardboard sheets F and G, which form a parallelogram, can be stopped appropriately without bending in the conveying direction.

[0127] The corrugated cardboard sheet manufacturing apparatus according to the 16th embodiment is a corrugated cardboard sheet manufacturing apparatus according to the 15th embodiment, further comprising a drive cylinder 83 as an adjustment device for adjusting the stopper 82 to a first position in the direction along the corrugation Ba and a second position in the same direction as the direction inclined by a predetermined angle θ with respect to the direction along the corrugation Ba. This allows the stopper 82 to be adjusted to an appropriate position by the drive cylinder 83.

[0128] The corrugated cardboard sheet according to the 17th embodiment is a corrugated cardboard sheet F, G formed by laminating flat liners A, C with a core B having a plurality of corrugated ridges Ba in a wave shape, wherein the sheet has a parallelogram shape in plan view, with two opposing first sides 101, 102 perpendicular to the direction along the corrugated ridges Ba, and two opposing second sides 103, 104 inclined by a predetermined angle θ with respect to the direction along the corrugated ridges Ba. This improves the bending accuracy of the corrugated cardboard sheets F, G and also improves their strength. Furthermore, it reduces the area of ​​waste when processing grooves and adhesive tabs on the corrugated cardboard sheets F, G.

[0129] The corrugated cardboard sheet according to the 18th embodiment is a corrugated cardboard sheet according to the 17th embodiment, further comprising first creases 111 and 112 along a direction perpendicular to the second two sides 103 and 104, and second creases 113 and 114 along a direction parallel to the second two sides 103 and 104. As a result, the first creases 111 and 112 and the second creases 113 and 114 are provided inclined with respect to the corrugated ridges Ba of the core B, allowing the corrugated cardboard sheets F and G to be folded at the appropriate position while ensuring sufficient strength.

[0130] The corrugated cardboard sheet according to the 19th embodiment is a corrugated cardboard sheet according to the 17th or 18th embodiment, further provided with adhesive tabs 121 and 122 extending in a direction perpendicular to the second two sides 103 and 104. This provides adhesive tabs 121 and 122 that are inclined with respect to the corrugations Ba of the core B, thereby improving the positional accuracy and strength of the adhesive tabs 121 and 122.

[0131] 10 Corrugated cardboard sheet manufacturing equipment 11, 12, 15, 16, 19 Mill roll stand 13, 17 Single facer 14, 18 Bridge 20 Preheater 21 Glue machine 22 Double facer 23 Rotary shaft 24 Slitter scorer 25 Cut-off (cutting device) 26 Defective product discharge device 27 Stacker 28 Web director 50 First knife cylinder 50A Second knife cylinder 50B Knife cylinder 51 Upper knife cylinder 52 Lower knife cylinder 53 Frame 54, 55 Bearing section 60 Speed ​​reduction device 63, 64, 65 Speed ​​reduction brush (speed reduction member) 70 Conveying device 71 Nip roll (conveying roll) 72 Receiving roll (conveying roll) 80 Stopping device 82 Stopper 91 Control device 91a Cut-off control device 91b Stacker control device 92 Production control device 101, 102 First two sides 103, 104 Second two sides 111, 112 First crease line 113, 114 Second crease line 121, 122 Adhesive flap A Front liner B, B1, B2 Core C, C1, C2 Back liner D, D1, D2 Single-sided corrugated cardboard sheet E, F Double-sided corrugated cardboard sheet O1, O2, O3, O4 Axis CL1 First cutting line CL2 Second cutting line

Claims

1. A cutting device for cutting a corrugated cardboard sheet formed by bonding together at least one flat liner and a core having a plurality of corrugated ridges, wherein the cutting device cuts the corrugated cardboard sheet into a parallelogram along a cutting line that is inclined by a predetermined angle with respect to the direction along the ridges.

2. The cutting device according to claim 1, wherein the core has a plurality of corrugated ridges formed at intervals in the direction of transport of the corrugated cardboard sheet, along a width direction perpendicular to the transport direction of the corrugated cardboard sheet, and the cutting line is along a direction inclined by a predetermined angle with respect to the width direction of the corrugated cardboard sheet so as to straddle at least one of the corrugated ridges.

3. The cutting device according to claim 1, comprising a first knife cylinder for cutting the corrugated cardboard sheet along a direction along the corrugations, and a second knife cylinder for cutting the corrugated cardboard sheet along a cutting line inclined by a predetermined angle with respect to the direction along the corrugations, wherein the use of at least one of the first knife cylinder and the second knife cylinder can be selected.

4. The cutting device according to claim 1, comprising a knife cylinder for cutting the corrugated cardboard sheet, and an adjustment device for adjusting the knife cylinder to a first position in the direction along the corrugation and a second position in the direction inclined by a predetermined angle with respect to the direction along the corrugation.

5. The cutting device according to claim 4, comprising a production management device having production management information for the corrugated cardboard sheet, and a control device to which production management information is input from the production management device, wherein the control device controls the adjustment device based on the production management information.

6. The cutting device according to claim 5, wherein the production management device determines a cutting angle that is inclined by a predetermined angle with respect to the width direction of the corrugated cardboard sheet so as to straddle at least one of the corrugated cardboard ridges, based on the shape and cutting width of the corrugated cardboard sheet.

7. The cutting device according to claim 5, wherein the control device determines a cutting angle that is inclined by a predetermined angle with respect to the width direction of the corrugated cardboard sheet so as to straddle at least one of the corrugated ridges, based on the shape and cutting width of the corrugated cardboard sheet.

8. A method for manufacturing a corrugated cardboard sheet, comprising: a method for manufacturing a corrugated cardboard sheet, wherein the corrugated cardboard sheet is cut into a parallelogram shape along a cutting line that is inclined by a predetermined angle with respect to the direction along the corrugations; 9. The method for manufacturing a corrugated cardboard sheet according to claim 8, wherein a die-cutting process is performed on a corrugated cardboard sheet cut into a parallelogram to form creases and adhesive tabs.

10. A corrugated cardboard sheet manufacturing apparatus comprising: a sheet laminating apparatus for bonding at least one flat liner and a core having a plurality of corrugated ridges to form a corrugated cardboard sheet; and a cutting apparatus according to claim 1 for cutting the corrugated cardboard sheet.

11. A corrugated cardboard sheet manufacturing apparatus according to claim 10, wherein a reduction device is arranged downstream of the cutting device in the conveying direction of the corrugated cardboard sheet, and the reduction device reduces the corrugated cardboard sheet by bringing a reduction member into contact with the upper surface of the corrugated cardboard sheet, and the reduction member is provided along the same direction as the direction of inclination by a predetermined angle.

12. The corrugated cardboard sheet manufacturing apparatus according to claim 11, further comprising an adjustment device for adjusting the deceleration member to a first position in the direction along the step and a second position in the same direction as the direction inclined by a predetermined angle with respect to the direction along the step.

13. A corrugated cardboard sheet manufacturing apparatus according to claim 10, wherein a conveying device is arranged downstream of the cutting device in the conveying direction of the corrugated cardboard sheet, and the conveying device conveys the corrugated cardboard sheet by bringing a conveying roll into contact with the corrugated cardboard sheet, and the conveying roll is provided along the same direction as the direction in which it is inclined by a predetermined angle.

14. The corrugated cardboard sheet manufacturing apparatus according to claim 13, further comprising an adjustment device for adjusting the conveying roll to a first position in the direction along the corrugations and a second position in the same direction as the direction inclined by a predetermined angle with respect to the direction along the corrugations.

15. A corrugated cardboard sheet manufacturing apparatus according to claim 13 or claim 14, wherein a stopping device is arranged downstream of the conveying device in the direction of conveying the corrugated cardboard sheet, and the downstream end of the corrugated cardboard sheet in the direction of conveying the corrugated cardboard sheet comes into contact with a stopper, and the stopper is provided along the same direction as the direction of inclination by a predetermined angle.

16. The corrugated cardboard sheet manufacturing apparatus according to claim 15, further comprising an adjustment device for adjusting the stopper to a first position in the direction along the corrugation and a second position in the same direction as the direction inclined by a predetermined angle with respect to the direction along the corrugation.

17. A corrugated cardboard sheet formed by bonding at least one flat liner and a core having a plurality of corrugated ridges, wherein the corrugated cardboard sheet has a parallelogram shape in plan view, with two opposing first sides perpendicular to the direction along the ridges, and two opposing second sides inclined by a predetermined angle with respect to the direction along the ridges.

18. The corrugated cardboard sheet according to claim 17, wherein a first crease is provided along a direction perpendicular to the two second sides, and a second crease is provided along a direction parallel to the two second sides.

19. The corrugated cardboard sheet according to claim 17 or claim 18, wherein adhesive tabs are provided extending in a direction perpendicular to the two second sides.

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