Corrugated board sheet inspection device, corrugated board sheet control device, and corrugated board sheet manufacturing device

Abstract

A corrugated board sheet inspection device for inspecting a surface shape of a liner in a corrugated board sheet formed by bonding at least one flat liner and a core having a plurality of corrugated crests, the corrugated board sheet inspection device comprising: a detector that is disposed on an upper-surface side of the liner with respect to a conveyance line for the corrugated board sheet, and that measures a surface irregularity shape of the liner over a predetermined detection length in a conveyance direction of the corrugated board sheet; and a calculation unit that calculates a deviation between a maximum protrusion portion and a maximum recess portion in the surface irregularity shape of the liner on the basis of a detection result from the detector.

Description

Corrugated Sheet Inspection Device, Corrugated Sheet Control Device, and Corrugated Sheet Manufacturing Device

[0001] The present disclosure relates to a corrugated sheet inspection device, a corrugated sheet control device, and a corrugated sheet manufacturing device.

[0002] A corrugating machine as a corrugated sheet manufacturing device 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 corrugated sheet. The double facer laminates the front liner to the single-sided corrugated sheet to form a double-sided corrugated sheet. The double-sided corrugated 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 the corrugated sheet.

[0003] For example, if there are variations in the water content of the core, the back liner, or the front liner of the corrugated sheet, or if there are variations in the amount of glue application, the back liner or the front liner may become loose and form a washboard. Therefore, it is necessary to detect the occurrence of a washboard during the manufacture of the corrugated sheet. As a device for detecting a washboard, for example, there is one described in the following patent document.

[0004] Japanese Patent No. 6653331

[0005] Conventional washboard detection devices place a sensor unit on the liner side of the corrugated cardboard sheet, and the sensor unit measures the distance to the surface of the liner to detect flatness. The sensor unit is attached to the frame of the corrugated cardboard sheet manufacturing equipment. Since the corrugated cardboard sheet manufacturing equipment is composed of various devices, vibrations from the equipment are transmitted to the sensor unit via the frame, causing the sensor unit to vibrate. When the sensor unit vibrates, the measurement accuracy of the sensor unit may decrease. In addition, corrugated cardboard sheets are transported along a conveyor line, but the corrugated cardboard sheets may flap around during transport. When the corrugated cardboard sheets flap around, the measurement accuracy of the sensor unit may decrease. It is conceivable to correct the measurement error of the sensor unit, but this presents the challenge of increasing the complexity of the equipment.

[0006] This disclosure aims to solve the aforementioned problems and to provide a corrugated cardboard sheet inspection device, a corrugated cardboard sheet control device, and a corrugated cardboard sheet manufacturing device that can measure the surface irregularities of the liner in a corrugated cardboard sheet with high precision.

[0007] A corrugated cardboard sheet inspection apparatus of the present disclosure for achieving the above objective is a corrugated cardboard sheet inspection apparatus for inspecting the surface shape of a liner in a corrugated cardboard sheet formed by bonding at least one flat liner and a core having a plurality of corrugated corrugations in a wave shape, comprising: a detector positioned on the surface side of the liner with respect to the corrugated cardboard sheet transport line and measuring the surface unevenness shape of the liner over a predetermined detection length in the transport direction of the corrugated cardboard sheet; and a calculation unit that calculates the deviation between the maximum convex part and the maximum concave part in the surface unevenness shape of the liner based on the detection result of the detector.

[0008] Furthermore, the corrugated cardboard sheet control device of this disclosure comprises a corrugated cardboard sheet inspection device, a control unit that controls manufacturing equipment for manufacturing the corrugated cardboard sheet based on a preset control amount, and a control amount correction unit that corrects the control amount based on the detection result of the corrugated cardboard sheet inspection device.

[0009] 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 the corrugated cardboard sheet inspection apparatus.

[0010] According to the corrugated cardboard sheet inspection apparatus, corrugated cardboard sheet control apparatus, and corrugated cardboard sheet manufacturing apparatus of this disclosure, the surface irregularities of the liner in a corrugated cardboard sheet can be measured with high precision.

[0011] Figure 1 is a schematic diagram showing a corrugated machine as a corrugated cardboard sheet manufacturing apparatus of this embodiment. Figure 2 is a block diagram showing the corrugated cardboard sheet manufacturing apparatus of this embodiment. Figure 3 is a schematic diagram showing an example of detector arrangement in the corrugated cardboard sheet inspection apparatus of this embodiment. Figure 4 is a schematic diagram showing the detector arranged downstream of a single facer. Figure 5 is a schematic diagram of a modified example where the detector is arranged downstream of a single facer. Figure 6 is a schematic diagram showing the detector of this embodiment arranged downstream of a double facer. Figure 7 is a side view showing the corrugated cardboard sheet inspection apparatus. Figure 8 is a top view showing the corrugated cardboard sheet inspection apparatus. Figure 9 is an explanatory diagram illustrating the inspection method using the corrugated cardboard sheet inspection apparatus. Figure 10 is a schematic diagram showing an example of the display of inspection results by the corrugated cardboard sheet inspection apparatus. Figure 11 is a schematic diagram showing an example of the display of inspection results by the corrugated cardboard sheet inspection apparatus.

[0012] 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.

[0013] <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 direction of transport of the corrugated cardboard sheet is along the X direction, which is the longitudinal direction of the corrugated machine.

[0014] 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.

[0015] 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.

[0016] 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.

[0017] 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.

[0018] 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 material removal device 26, and a stacker 27.

[0019] 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.

[0020] 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.

[0021] 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.

[0022] The single facer 13 processes the heated core B1 into a corrugated shape, glues it to each corrugated top, and then adheres the heated back liner C1 to form a single-sided corrugated cardboard sheet D1. A lifting conveyor 28 is provided downstream of the single facer 13 in the transport direction of the single-sided corrugated cardboard sheet D1, and the single facer 13 transports the single-sided corrugated cardboard sheet D1 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.

[0023] 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. A lifting conveyor 29 is provided downstream of the single facer 17 in the transport direction of the single-sided corrugated cardboard sheet D2, and the single facer 17 transports 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.

[0024] Furthermore, the paper guide device 30 is provided on the downstream side of the bridges 14 and 18 in the transport direction. The paper guide device 30 adjusts the Y-direction positions of the single-sided corrugated cardboard sheets D1 and D2 between the bridges 14 and 18 and the double facer 22.

[0025] 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.

[0026] 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.

[0027] The glue machine 21 has gluing rolls 44 and 45 arranged in the Z direction. The gluing roll 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, to apply glue. The gluing roll 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, to apply 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.

[0028] 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.

[0029] 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.

[0030] 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 removal 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 removal 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 and discharges them outside the machine as a product.

[0031] <Control System of Corrugated Machine> Figure 2 is a block diagram showing the corrugated cardboard sheet manufacturing apparatus of this embodiment.

[0032] As shown in Figures 1 and 2, the corrugated machine 10 includes 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, defect removal device 26, and stacker 27. Hereafter, 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, defect removal device 26, and stacker 27 will be collectively referred to as the manufacturing equipment 51.

[0033] The corrugated cardboard machine 10 includes a control device (corrugated cardboard sheet control device) 60 that controls the manufacturing equipment 51. The control device 60 includes an inspection device (corrugated cardboard sheet inspection device) 61, a control amount correction unit 62, and a control unit 63. The inspection device 61 has a plurality of (two in this embodiment) detectors 71, 72, a calculation unit 73, and a determination unit 74. The control device 60 is also connected to an operation unit 52, a storage unit 53, a display unit 54, a notification unit 55, and a production management device 56.

[0034] The corrugating machine 10 manufactures single-sided corrugated cardboard sheets D1 and D2 by laminating back liners C1 and C2 to corrugated cores B1 and B2, respectively, and manufactures double-sided corrugated cardboard sheets E by laminating a front liner A to single-sided corrugated cardboard sheet D1 or single-sided corrugated cardboard sheet D2, and manufactures corrugated cardboard sheet F by cutting double-sided corrugated cardboard sheet E to a predetermined length. The inspection device 61 inspects the back liners C1 and C2 and the front liner A of the single-sided corrugated cardboard sheet D1 or single-sided corrugated cardboard sheet D2, double-sided corrugated cardboard sheet E or double-sided corrugated cardboard sheet F. Specifically, the inspection device 61 detects washboard by inspecting the surface shape of the back liners C1 and C2 and the front liner A.

[0035] The control amount correction unit 62 corrects the control amount used to control the manufacturing equipment 51 (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, defect removal device 26, stacker 27) for manufacturing corrugated cardboard sheets F, based on the detection results of the inspection device 61. The control unit 63 controls the driving of the manufacturing equipment 51 based on a preset control amount or a corrected control amount corrected by the control amount correction unit 62.

[0036] Furthermore, the control variable correction unit 62 and control unit 63 that constitute the control device 60, and the calculation unit 73 and determination unit 74 that constitute the inspection device 61, are each computers, and are realized by various programs stored in the memory unit being executed using RAM as the working area by a CPU (Central Processing Unit) or MPU (Micro Processing Unit), for example.

[0037] The operation unit 52 allows the operator to input various data to the control device 60. The operation unit 52 is, for example, a keyboard or a touch-sensitive display. The storage unit 53 stores the calculation results calculated by the calculation unit 73 of the inspection device 61 and the judgment results determined by the judgment unit 74. The storage unit 53 also stores the corrected control amount corrected by the control amount correction unit 62 of the control device 60 and the preset control amount. The storage unit 53 also stores various programs executed by the control device 60.

[0038] The display unit 54 displays the inspection results of the inspection device 61, etc. The display unit 54 is, for example, a monitor or a printer. The notification unit 55 notifies the inspection results of the inspection device 61, etc. The notification unit 55 notifies, for example, when the inspection device 61 determines that the washboard is defective. The notification unit 55 is, for example, a rotating light indicator or a horn.

[0039] The production management device 56 holds production management information for corrugated cardboard sheets and outputs this production management information to the control device 60. The production management information includes control quantities for the manufacturing equipment 51 according to the type of corrugated cardboard sheet. The control device 60 controls the manufacturing equipment 51 based on the production management information.

[0040] Incidentally, the control quantity correction unit 62 and the control unit 63 as the control device 60 may be provided individually for the mill roll stands 11, 12, 15, 16, 19, the single facers 13, 17, the bridges 14, 18, the preheater 20, the glue machine 21, the double facer 22, the rotary shear 23, the slitter scorer 24, the cutoff 25, the defect removal device 26, and the stacker 27 as the manufacturing equipment 51, respectively.

[0041] Incidentally, details of the control device 60 including the inspection device 61 will be described later.

[0042] <Arrangement Example of Detectors> FIG. 3 is a schematic diagram showing an arrangement example of detectors in the corrugated sheet inspection device of the present embodiment.

[0043] As shown in FIG. 3, the two detectors 71 and 72 are arranged on the conveyance line of the corrugated sheet. Since the detectors 71 and 72 inspect the surface shapes of the back liners C 1, C t and the front liner A, they are arranged on the downstream side of the single facer 13 or the downstream side of the single facer 17. However, the first detector 71 is preferably arranged between the single facers 13, 17 and the double facer 22. The first detector 71 is arranged on the downstream side of the single facers 13, 17 and between the preheater 20 and the glue machine 21. The first detector 71 is composed of first detectors 71a and 71b. The first detector 71a inspects the back liner C 1 of the single-sided corrugated sheet D 1, and the first detector 71b inspects the back liner C t of the single-sided corrugated sheet D 2.

[0044] However, the first detector 71 is not limited to this position. For example, the first detector 71Aa may be arranged between the bridge 14 and the preheater 20 on the downstream side of the single facer 13, and the first detector 71Ab may be arranged between the bridge 18 and the preheater 20 on the downstream side of the single facer 17. The first detector 71Aa inspects the back liner C 1 of the single-sided corrugated sheet D 1, and the first detector 71Ab inspects the back liner C t of the single-sided corrugated sheet D 2.

[0045] Furthermore, the first detector 71Ba may be positioned between the single facer 13 and the bridge 14, and the first detector 71Bb may be positioned between the single facer 17 and the bridge 18. The first detector 71Ba inspects the back liner C1 of the single-sided corrugated cardboard sheet D1, and the first detector 71Bb inspects the back liner C2 of the single-sided corrugated cardboard sheet D2. In addition, the first detectors 71Ca and 71Cb may be positioned between the glue machine 21 and the double facer 22. The first detector 71Ca inspects the back liner C1 of the single-sided corrugated cardboard sheet D1, and the first detector 71Cb inspects the back liner C2 of the single-sided corrugated cardboard sheet D2.

[0046] The second detector 72 is located downstream of the double facer 22 and is positioned between the slitter scorer 24 and the cutoff 25. The second detector 72 consists of second detectors 72a and 72b. Second detector 72a inspects the back liner C1 of the double-sided corrugated cardboard sheet E, and second detector 72b inspects the front liner A of the double-sided corrugated cardboard sheet E.

[0047] However, the second detector 72 is not limited to this position. For example, the second detector 72A may be positioned between the double facer 22 and the rotary shank 23. The second detector 72A consists of second detectors 72Aa and 72Ab, where the second detector 72Aa inspects the back liner C1 of the double-sided corrugated cardboard sheet E, and the second detector 72Ab inspects the front liner A of the double-sided corrugated cardboard sheet E.

[0048] Further, the second detector 72B may be disposed between the cutoff 25 and the stacker 27 on the downstream side of the double facer 22. The second detector 72B is composed of second detectors 72Ba and 72Bb. The second detector 72Ba inspects the back liner C1 of the double-sided corrugated cardboard sheet F, and the second detector 72Bb inspects the front liner A of the double-sided corrugated cardboard sheet F. Note that, since the washboard is more likely to be significantly deformed on the downstream side in the conveyance direction in the corrugating machine 10, it is desirable to dispose the detector on the more downstream side. However, when controlling the manufacturing equipment 51 based on the detection result of the inspection device 61, considering the control delay, it is better to make the determination as to whether the single-sided corrugated cardboard sheet D or the front liner A is a washboard at an earlier stage. For this reason, the second detector 72B is disposed at a position where the double-sided corrugated cardboard sheet E is near the completion of manufacturing and the detection result can be obtained at an earlier stage.

[0049] <Configuration in which the detector is disposed on the downstream side of the single facer> FIG. 4 is a schematic view in which the detector is disposed on the downstream side of the single facer.

[0050] As shown in FIG. 4, the paper guide devices 30 are respectively provided on the downstream side in the conveyance direction of the bridges 14 and 18. The paper guide device 30 includes a twisting roller (not shown), and the twisting roller contacts the upper surfaces of the single-sided corrugated cardboard sheets D1 and D2, that is, the back liners C1 and C2. With the twisting roller contacting the single-sided corrugated cardboard sheet, one end of the twisting roller is moved in the X direction by a moving device (not shown). Then, the twisting roller is inclined in the X direction, and the single-sided corrugated cardboard sheets D1 and D2 are guided by the twisting roller. Thereby, the Y-direction positions of the single-sided corrugated cardboard sheets D1 and D2 are adjusted, and the conveyance with meandering or bias in either one of the Y directions is suppressed.

[0051] The preheater 20 is constructed by rotatably supporting preheating rolls 41, 42, and 43 on a frame 101. The preheating rolls 41, 42, and 43 heat the front liner A, the single-sided corrugated cardboard sheet D2, and the single-sided corrugated cardboard sheet D1. Guide rolls 102a, 102b, and 102c and winding angle adjustment rolls 103a, 103b, and 103c are positioned on the upstream side of the preheating rolls 41, 42, and 43 in the conveying direction, while guide rolls 104a, 104b, and 104c are positioned on the downstream side. The winding angle adjustment rolls 103a, 103b, and 103c adjust the winding angle of the front liner A, the single-sided corrugated cardboard sheet D2, and the single-sided corrugated cardboard sheet D1 by moving the outer circumference of the preheating rolls 41, 42, and 43 in the circumferential direction, thereby adjusting the preheating temperature.

[0052] The glue machine 21 is constructed with glue rolls 44 and 45 rotatably supported on a frame 105. Each glue roll 44 and 45 applies glue from glue dams 106a and 106b to the cores B2 and B1 of the single-sided corrugated cardboard sheets D2 and D1, respectively. The glue rolls 44 and 45 are positioned in contact with meter rolls 107a and 107b to adjust the amount of glue applied, and rider rolls 108a and 108b are positioned opposite each other. The double facer 22 has preheaters 110 and 111 rotatably supported on a frame 109. The top liner A is guided to the double facer 22 via the preheater 110, and the single-sided corrugated cardboard sheets D1 and D2 are guided to the double facer 22 via the preheater 111.

[0053] The first detector 71a, which constitutes the first detector 71, is positioned between the preheater 20 and the glue machine 21 and is fixed to the frame 105 of the glue machine 21. The first detector 71a is positioned to face the surface side of the back liner C1 of the single-sided corrugated cardboard sheet D1 being transported from the preheater 20 to the glue machine 21, with a gap between them. The first detector 71b, which constitutes the first detector 71, is positioned between the preheater 20 and the glue machine 21 and is fixed to the frame 105 of the glue machine 21. The first detector 71b is positioned to face the surface side of the back liner C2 of the single-sided corrugated cardboard sheet D2 being transported from the preheater 20 to the glue machine 21, with a gap between them.

[0054] However, the first detectors 71a and 71b are not limited to these positions. For example, the first detector 71Aa, which constitutes the first detector 71, is positioned between the paper guide device 30 and the preheater 20 and fixed to the frame 101 of the preheater 20. The first detector 71Aa is positioned to face the surface side of the back liner C1 of the single-sided corrugated cardboard sheet D1, which is transported from the paper guide device 30 to the preheater 20 and wrapped around the preheating roll 43, with a gap between them. The first detector 71Ab, which constitutes the first detector 71, is positioned between the paper guide device 30 and the preheater 20 and fixed to the frame 101 of the preheater 20. The first detector 71Ab is positioned to face the surface side of the back liner C2 of the single-sided corrugated cardboard sheet D2, which is transported from the paper guide device 30 to the preheater 20 and wrapped around the preheating roll 42, with a gap between them.

[0055] Figure 5 is a schematic diagram of a modified example in which the detector is placed downstream of the single phaser.

[0056] As shown in Figure 5, the single facer 13 includes a belt roll 121, a tension roll 122, a pressure belt 123, an upper roll 124, a lower roll 125, and a gluing device 126.

[0057] The belt roll 121 is rotatable by a drive device (not shown). The tension roll 122 is rotatably supported at a predetermined distance from the belt roll 121. The pressure belt 123 is an endless belt that is wrapped between the belt roll 121 and the tension roll 122. The upper roll 124 is rotatable by a drive device (not shown) and has a corrugated outer surface. The upper roll 124 is positioned below the pressure belt 123 in the Z direction, between the belt roll 121 and the tension roll 122, and its corrugated outer surface is in pressurized contact with the lower surface of the pressure belt 123. The lower roll 125, like the upper roll 124, has a corrugated outer surface and is positioned below the upper roll 124 in the Z direction, engaging with the outer surface of the upper roll 124. The belt roll 121, tension roll 122, upper roll 124, and lower roll 125 are heated by steam flowing through their interiors. The core B1 and the back liner C are heated via the pressure belt 123 and the upper roll 124.

[0058] The gluing device 126 is positioned near the upper roll 124 in the X direction. The gluing device 126 includes a glue dam 127, a gluing roll 128, a meter roll 129, and a glue scraping blade 130. The glue dam 127 stores a predetermined amount of glue. The gluing roll 128 applies the glue stored in the glue dam 127 to the core B1 conveyed by the upper roll 124 to perform gluing. The meter roll 129 adjusts the amount of glue attached to the outer surface of the gluing roll 128 by contacting and rotating synchronously with the outer surface of the gluing roll 128. The glue scraping blade 130 scrapes off excess glue attached to the outer surface of the meter roll 129 by contacting the outer surface of the meter roll 129 and removing it from the gluing roll 128.

[0059] The single facer 13 is equipped with a preheating roll 131 and a winding angle adjustment roll 132 that introduce the core B1 supplied from the splicer 31 (see Figure 1) between the upper roll 124 and the lower roll 125. The winding angle adjustment roll 132 adjusts the winding angle of the core B1 by moving the outer circumference of the preheating roll 131 in the circumferential direction, thereby adjusting the preheating temperature. The single facer 13 is also equipped with a preheating roll 133 and a winding angle adjustment roll 134 that introduce the back liner C1 supplied from the splicer 33 (see Figure 1) between the pressure belt 123 and the upper roll 124. The winding angle adjustment roll 134 adjusts the winding angle of the back liner C1 by moving the outer circumference of the preheating roll 133 in the circumferential direction, thereby adjusting the preheating temperature.

[0060] Furthermore, a pick-up conveyor 28 is provided on the downstream side of the single facer 13 in the direction of transport of the single-sided corrugated cardboard sheet D1. The pick-up conveyor 28 guides the single-sided corrugated cardboard sheet D1 formed by the single facer 13 and supplies it to the bridge 14 (see Figure 1). The pick-up conveyor 28 has a first lower belt 172, a second lower belt 173, and an upper belt 174. The first lower belt 172 and the upper belt 174 are arranged diagonally upward, and the second lower belt 173 is arranged horizontally. The first lower belt 172, the second lower belt 173, and the upper belt 174 can be driven by a drive device (not shown). The single-sided corrugated cardboard sheet D1 is transported sandwiched between the first lower belt 172, the second lower belt 173, and the upper belt 174.

[0061] The back liner C1 is wound around the preheating roll 133 and then, together with the pressure belt 123 guided by the belt roll 121, is transferred to the nip portion between the pressure belt 123 and the upper roll 124. Meanwhile, the core B1 is wound around the preheating roll 131 and then processed into a corrugated shape at the meshing portion between the upper roll 124 and the lower roll 125, and then, guided by the upper roll 124, is transferred to the nip portion between the pressure belt 123 and the upper roll 124.

[0062] The core B1 is processed into a corrugated shape at the interlocking section between the upper roll 124 and the lower roll 125, and then glued by the gluing device 126. The glue stored in the glue dam 127 adheres to the rotating gluing roll 128, and the amount of glue applied to the outer surface is adjusted by the meter roll 129. The core B1, which has been processed into a corrugated shape at the interlocking section between the upper roll 124 and the lower roll 125, comes into contact with the gluing roll 128, and is glued to the top of each corrugation. When the glued core B1 is transferred to the nip section between the pressure belt 123 and the upper roll 124, it is bonded to the back liner C1, forming a single-sided corrugated cardboard sheet D1.

[0063] The first detector 71Ba, which constitutes the first detector 71, is positioned between the single facer 13 and the bridge 14 (see Figure 1). For example, the first detector 71Ba is positioned between the single facer 13 and the pick-up conveyor 28 and is fixed to the frame (not shown) of the pick-up conveyor 28. The first detector 71Ba is positioned to face the surface side of the back liner C1 of the single-sided corrugated cardboard sheet D1 that is transported from the single facer 13 to the pick-up conveyor 28, with a gap between them.

[0064] However, the first detector 71Ba is not limited to that position. The first detector 71Ba may be located, for example, in the middle of the pick-up conveyor 28 or downstream of the pick-up conveyor 28.

[0065] Although the first detector 71Ba, which constitutes the first detector 71, has been described, the first detector 71Bb, which also constitutes the first detector 71, is positioned between the single facer 17 and the bridge 18 (see Figure 1), similar to the first detector 71Ba. For example, the first detector 71Bb is positioned between the single facer 17 and the pick-up conveyor, in the middle of the pick-up conveyor 29, and downstream of the pick-up conveyor 29.

[0066] <Configuration with the detector positioned downstream of the double phaser> Figure 6 is a schematic diagram of a configuration in which the detector is positioned downstream of the double phaser.

[0067] As shown in Figure 6, the cutoff 25 has a knife cylinder 140. The knife cylinder 140 has an upper knife cylinder 141 and a lower knife cylinder 142. The upper knife cylinder 141 and the lower knife cylinder 142 are positioned on the frame 143 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).

[0068] The upper knife cylinder 141 is supported at each end by bearings so as to be rotatable about the axis O1 in the axial direction. The lower knife cylinder 142 is supported at each end by bearings so as to be rotatable about the axis O2 in the axial direction. The upper knife cylinder 141 has a cylindrical shape, and an upper blade 141a is mounted on its outer circumference along the axial direction. The lower knife cylinder 142 has a cylindrical shape, and a lower blade 142a is mounted on its outer circumference along the axial direction.

[0069] At the cutoff 25, a conveyor belt 146 is positioned on the upstream side, and a conveyor belt 147 is positioned on the downstream side. The conveyor belt 146 transports continuous double-sided corrugated cardboard sheets E, and the conveyor belt 147 transports flat double-sided corrugated cardboard sheets F.

[0070] Furthermore, a measurement unit 150 is positioned upstream of the cutoff 25. The measurement unit 150 includes a measurement wheel 151 and a rotary encoder 152. The measurement wheel 151 and the rotary encoder 152 are rotatably supported on the frame 153 of the measurement unit 150. The measurement wheel 151 and the rotary encoder 152 are configured, for example, by connecting their rotating shafts with a coupling. The measurement wheel 151 is positioned above the conveying line of the double-sided corrugated cardboard sheet E. The rotary encoder 152 is connected to the measurement wheel 151. The measurement wheel 151 is a rotating body that contacts the surface of the back liner C1 of the double-sided corrugated cardboard sheet E and rotates in conjunction with the conveying of the double-sided corrugated cardboard sheet E. The rotary encoder 152 outputs a pulse signal corresponding to the rotation of the measurement wheel 151.

[0071] The control device 60 (see Figure 2) receives a pulse signal from the rotary encoder 152. Based on the pulse signal, the control device 60 calculates the rotation speed of the rotary encoder 152 and calculates the transport distance of the double-sided corrugated cardboard sheet E from the rotation speed. Then, the control device 60 activates the cutoff 25 according to the transport distance of the double-sided corrugated cardboard sheet E.

[0072] Therefore, the cutoff 25 is rotatable by a control signal from the control device 60, with the upper knife cylinder 141 rotating counterclockwise in Figure 6 and the lower knife cylinder 142 rotating clockwise in Figure 6. When a continuous sheet of double-sided corrugated cardboard E is transported by the conveyor belt 146, the sheet of double-sided corrugated cardboard E is cut by the upper blade 141a and lower blade 142a of the synchronously rotating upper knife cylinder 141 and lower knife cylinder 142. The cut, plate-shaped sheet of double-sided corrugated cardboard F is then transported by the conveyor belt 147.

[0073] The second detector 72a, which constitutes the second detector 72, is located downstream of the double facer 22 and is positioned in the measurement unit 150, and is fixed to the frame 153 of the measurement unit 150. The second detector 72a is positioned to face the surface side of the back liner C1 of the double-sided corrugated cardboard sheet E, which is transported from the slitter scorer 24 to the measurement unit 150, with a gap between them. The second detector 72b, which constitutes the second detector 72, is located downstream of the double facer 22 and is positioned in the measurement unit 150, and is fixed to the frame 153 of the measurement unit 150. The second detector 72b is positioned to face the surface side of the front liner A of the double-sided corrugated cardboard sheet E, which is transported from the slitter scorer 24 to the measurement unit 150, with a gap between them.

[0074] <Corrugated Cardboard Sheet Inspection Device> As shown in Figures 2 and 3, the inspection device 61 includes a first detector 71, a second detector 72, a calculation unit 73, and a determination unit 74. The first detector 71 and the second detector 72 are positioned on the surface side of the back liners C1 and C2 and the surface side of the front liner A with respect to the corrugated cardboard sheet transport line. The first detector 71 and the second detector 72 are positioned at different positions in the transport direction of the corrugated cardboard sheet. The first detector 71 has first detectors 71a and 71b, which are positioned downstream of the single facers 13 and 17, between the preheater 20 and the glue machine 21. The first detector 71a inspects the back liner C1 of the single-sided corrugated cardboard sheet D1, and the first detector 71b inspects the back liner C2 of the single-sided corrugated cardboard sheet D2.

[0075] The second detector 72 has second detectors 72a and 72b, and is positioned downstream of the double facer 22 and between the slitter scorer 24 and the cutoff 25. The second detector 72a inspects the back liner C1 of the double-sided corrugated cardboard sheet E, and the second detector 72b inspects the front liner A of the double-sided corrugated cardboard sheet E.

[0076] The specific processing of the control device 60, including the inspection device 61, will be described below. Since the first detector 71 and the second detector 72 have almost identical functions, differing only in the object being inspected, the first detector 71 will be described, and the description of the second detector 72 will be omitted. Furthermore, since the first detector 71a and the first detector 71b also have almost identical functions, differing only in the object being inspected, the first detector 71 will be described as inspecting the back liner C of a single-sided corrugated cardboard sheet D.

[0077] Figure 7 is a side view of the corrugated cardboard sheet inspection device, and Figure 8 is a top view of the corrugated cardboard sheet inspection device.

[0078] As shown in Figures 2, 7, and 8, the first detector 71 is positioned on the surface side of the back liner C of the single-sided corrugated cardboard sheet D with respect to the corrugated cardboard sheet transport line. The surface of the back liner C is the side to which the corrugated core B is not attached. The first detector 71 is positioned at a predetermined distance from the surface of the back liner C of the single-sided corrugated cardboard sheet D. One first detector 71 is positioned at the center in the width direction of the single-sided corrugated cardboard sheet D, but it may also be positioned on one or the other side in the width direction of the single-sided corrugated cardboard sheet D. Multiple first detectors may also be positioned in the width direction of the single-sided corrugated cardboard sheet D. The first detector 71 measures the surface irregularities of the back liner C over a predetermined detection length in the transport direction of the corrugated cardboard sheet.

[0079] Here, the detected length is greater than or equal to the length between the corrugations of adjacent core B in the direction of transport of the corrugated cardboard sheet. The core B has a corrugated shape, with corrugations Ba protruding to one side perpendicular to the in-plane direction and corrugations Bb protruding to the other side perpendicular to the in-plane direction, arranged alternately in the direction of transport of the corrugated cardboard sheet. The single facers 13 and 17 form a single-sided corrugated cardboard sheet D by gluing a flat back liner C to the corrugated core B. At this time, the vertices of multiple corrugations Ba of the corrugated core B are adhered to the back surface of the flat back liner C. Therefore, the detected length is greater than or equal to the length between the corrugations Ba of adjacent core B.

[0080] Furthermore, the single-sided corrugated cardboard sheet D is then bonded to the corrugated core B by a double facer 22, with the flat surface liner A being glued to form a double-sided corrugated cardboard sheet E. At this time, the vertices of the multiple corrugations Bb of the corrugated core B are bonded to the back surface of the flat surface liner A.

[0081] The first detector 71 is a distance sensor that measures the distance from a mounting position located on the surface side of the back liner C relative to the corrugated cardboard sheet transport line to the surface of the back liner C. The distance sensor may be, for example, a laser distance sensor, which irradiates a laser beam at a predetermined irradiation angle toward the object to be measured, receives the laser beam reflected from the object to be measured, measures the time from irradiation to reception and calculates the distance. However, the first detector 71 is not limited to a laser distance sensor.

[0082] For example, when continuously measuring a single point using a laser distance sensor, it becomes difficult to accurately measure the distance from the laser distance sensor to the corrugated cardboard sheet (back liner C) due to disturbances such as vibrations of the corrugated cardboard sheet and vibrations of the laser distance sensor itself. If the measured distance is not accurate, it is not possible to accurately determine whether or not the corrugated cardboard sheet is a washboard. Furthermore, in order to accurately measure the measured distance, it is necessary to correct for the measurement distance including deviations due to disturbances. Therefore, in this embodiment, for example, a laser distance sensor utilizing the triangulation principle is used to simultaneously measure the distance to the surface of the corrugated cardboard sheet (back liner C) within a predetermined detection length area. In this case, since simultaneous measurement is possible, there is no need to correct for disturbances such as vibrations of the corrugated cardboard sheet and vibrations of the laser distance sensor itself. Thus, the constraints on the measurement location of the corrugated cardboard sheet manufacturing apparatus and the mounting position of the detector are reduced.

[0083] The first detector 71 simultaneously measures the distance to the surface of multiple back liner C layers that are offset in the transport direction of the corrugated cardboard sheet within a predetermined detection length area. The detection area DA of the first detector 71 is the range of the detection length in a direction parallel to the transport direction of the corrugated cardboard sheet. That is, for example, the first detector 71 irradiates laser light at a predetermined angle toward the detection area DA parallel to the transport direction of the corrugated cardboard sheet, and simultaneously measures the distance from the mounting position to the surface of the back liner C layer at multiple different positions in the transport direction within the detection area DA.

[0084] The first detector 71 is a triangulation-type laser distance sensor, and since the emitted laser light is reflected off the surface of the back liner C, which is the object to be measured, the optical path of the laser light is triangular. Therefore, the first detector 71 measures the vertical distance from the first detector 71 to the detection position of the back liner C, that is, the surface irregularity shape of the back liner C, based on the shortest distance from the mounting position to the back liner C, the diagonal distance from the mounting position to the detection position of the back liner C, and the distance in the transport direction of the corrugated cardboard sheet from the position of the back liner C that is the shortest distance from the mounting position to the detection position of the back liner C.

[0085] The calculation unit 73 calculates the deviation between the maximum protrusion and the maximum recess in the surface unevenness shape of the back liner C based on the detection result of the first detector 71. Specifically, a single-sided corrugated cardboard sheet D is formed by bonding a flat back liner C to each corrugation Ba of the corrugated core B. As a result, as the single-sided corrugated cardboard sheet D dries, the back liner C tends to sag between the corrugations Ba of the core B, easily becoming a washboard.

[0086] The maximum protrusion in the surface irregularities of the back liner C is the position where the back liner C protrudes furthest toward the surface. Therefore, the maximum protrusion is the minimum value measured by the first detector 71 in the detection area DA measured by the first detector 71. Here, the minimum value (maximum protrusion) is the position of the back liner C bonded to the stepped ridges Ba of the core B. On the other hand, the maximum recess in the surface irregularities of the back liner C is the position where the back liner C is recessed furthest toward the back surface. Therefore, the maximum recess is the maximum value measured by the first detector 71 in the detection area DA measured by the first detector 71. Here, the maximum value (maximum recess) is the position of the back liner C supported between adjacent stepped ridges Ba of the core B.

[0087] In this case, the detection region DA of the first detector 71 is a region containing two or more stepped peaks Ba, but it may also be a region containing three or more stepped peaks Ba. In this case, the first detector 71 measures the maximum convex portion (minimum value) and the maximum concave portion (maximum value) between each of the multiple stepped peaks Ba. Then, the calculation unit 73 calculates multiple deviations calculated between each stepped peak Ba based on the multiple maximum convex portions (minimum value) and the multiple maximum concave portions (maximum value) in the detection region DA, and calculates the average deviation by averaging the multiple deviations.

[0088] The determination unit 74 determines that the back liner C is a washboard if the deviation calculated by the calculation unit 73 exceeds a preset determination value. The determination value is preferably set in advance through experiments or simulations, taking into account the quality of the double-sided corrugated cardboard sheet F.

[0089] In this example, the first detector 71 simultaneously measures the distance from the mounting position to the surface of the back liner C at multiple locations in the detection area DA parallel to the transport direction of the corrugated cardboard sheet, but the configuration is not limited to this. As shown in Figure 8, for example, the first detector 71 may simultaneously measure the distance from the mounting position to the surface of the back liner C at multiple locations in the detection area DA1 along a direction inclined by a predetermined angle (for example, 30 to 60 degrees) in the width direction with respect to the transport direction of the corrugated cardboard sheet. In this case, the first detector 71 measures the surface irregularities of the back liner C over a length of inclination detection in the direction inclined in the width direction of the corrugated cardboard sheet with respect to the transport direction of the corrugated cardboard sheet.

[0090] The first detector 71 simultaneously measures the distance from the mounting position to the surface of the back liner C in the inclined detection area DA1, but there is no change in the processing of the calculation unit 73 and the determination unit 74. However, the first detector 71 simultaneously measures the distance from the mounting position to the surface of the back liner C in the inclined detection area DA1 at a position shifted in the width direction of the single-sided corrugated cardboard sheet D. Therefore, the calculation unit 73 can obtain the width direction unevenness shape of the back liner C of the single-sided corrugated cardboard sheet D and calculate the amount of warping in the width direction of the single-sided corrugated cardboard sheet D (back liner C). The determination unit 74 then determines whether the amount of warping calculated by the calculation unit 73 exceeds a preset determination value.

[0091] Here, we will explain the specific inspection method for single-sided corrugated cardboard sheets D using the inspection device 61. Figure 9 is an explanatory diagram illustrating the inspection method using the corrugated cardboard sheet inspection device.

[0092] As shown in Figures 2 and 9, a single-sided corrugated cardboard sheet D is constructed by bonding the tops of multiple corrugations Ba on the core B to the back surface of the back liner C. In this case, the distance between adjacent corrugations Ba1 and Ba2 on the core B in the transport direction of the corrugated cardboard sheet is defined as 1 pitch (1P). The first detector 71 measures the surface irregularities of the back liner C over a predetermined detection length. Here, the detection length is greater than or equal to the distance between adjacent corrugations Ba on the core B, that is, greater than or equal to 1 pitch (1P). The first detector 71 simultaneously measures the distance to the surface of multiple back liner C at positions shifted in the transport direction of the corrugated cardboard sheet within a range of at least 1 pitch (1P). In this case, the number of measurements that the first detector 71 simultaneously measures within a range of 1 pitch (1P) depends on the resolution capability of the first detector 71 and is set as appropriate.

[0093] The first detector 71 simultaneously measures multiple distances to the surface of the back liner C within a range of one pitch (1P). The calculation unit 73 calculates the deviation between the maximum convexity and the maximum concaveness in the surface unevenness shape of the back liner C based on the multiple distances simultaneously measured by the first detector 71 within a range of one pitch (1P). Here, the maximum convexity in the surface unevenness shape of the back liner C is the minimum value measured by the first detector 71 within a range of one pitch (1P). The minimum value is Lmin, the distance from the first detector 71 to the surface of the back liner C bonded to the stepped Ba1 or stepped Ba2 of the core B. On the other hand, the maximum concaveness in the surface unevenness shape of the back liner C is the maximum value measured by the first detector 71 within a range of one pitch (1P). The maximum value is Lmax, the distance from the first detector 71 to the surface of the back liner C supported between the stepped Ba1 and stepped Ba2 of the core B.

[0094] In other words, the calculation unit 73 calculates the deviation ΔL (distance Lmax - distance Lmin) between the distance Lmin to the maximum convexity and the distance Lmax to the maximum concaveness, both measured simultaneously within a 1-pitch (1P) range measured by the first detector 71. When the detection length is 2-pitch (2P) or more, rather than 1-pitch (1P), the calculation unit 73 calculates multiple deviations ΔL, averages the multiple deviations ΔL, calculates the average deviation, and outputs it. The calculation unit 73 may also output the maximum deviation ΔL among the multiple deviations ΔL.

[0095] The determination unit 74 determines whether the deviation ΔL (or average deviation ΔL, maximum knit difference ΔL) calculated by the calculation unit 73 exceeds the determination value. If the determination unit 74 determines that the deviation ΔL exceeds the determination value, it determines that the back liner C is a washboard.

[0096] <Control device> As shown in Figure 2, the control device 60 includes an inspection device 61, a control amount correction unit 62, and a control unit 63.

[0097] As described above, the inspection device 61 determines whether or not the back liner C of the single-sided corrugated cardboard sheet D is a washboard. The control amount correction unit 62 corrects the control amount of the manufacturing equipment 51 based on the detection result of the inspection device 61. The control unit 63 controls the manufacturing equipment 51 based on a preset control amount or a corrected control amount corrected by the control amount correction unit 62.

[0098] Specifically, when the inspection device 61 determines that the back liner C of the single-sided corrugated cardboard sheet D is a washboard, the control amount correction unit 62 adjusts the control amount to reduce the amount of adhesive used to bond the back liner C and the core B. That is, as shown in Figure 5, in the single facer 13, the gluing device 126 uses the gluing roll 128 to apply the adhesive stored in the adhesive dam 127 to the core B1 being conveyed by the upper roll 124 to perform gluing.

[0099] Therefore, in order to reduce the amount of adhesive used to bond the back liner C and the core B, the operation of the meter roll 129 and the adhesive scraping blade 130 is controlled to reduce the amount of adhesive adhering to the outer surface of the adhesive application roll 128. Specifically, the control amount correction unit 62 adjusts the control amount that controls the operation of the meter roll 129 and the adhesive scraping blade 130 and outputs a corrected control amount. The control amount for controlling the operation of the meter roll 129 and the adhesive scraping blade 130 has a predetermined adjustment range set in advance, and the control amount correction unit 62 adjusts the control amount within the predetermined adjustment range. For example, it is preferable to prepare a map (matrix diagram) that defines the relationship between the transport speed of the single-sided corrugated cardboard sheet D, the control amount of adhesive adhesion, and the deviation ΔL.

[0100] Furthermore, when the inspection device 61 determines that the back liner C of the single-sided corrugated cardboard sheet D is a washboard, the control amount correction unit 62 adjusts the control amount to reduce the amount of heating required to heat the back liner C. That is, as shown in Figure 5, the back liner C supplied from the splicer 33 (see Figure 1) is wrapped around the preheating roll 133 and preheated by the single facer 13.

[0101] Therefore, in order to reduce the amount of heating required to heat the back liner C, the amount of winding (winding angle) of the back liner C wrapped around the preheating roll 133 is reduced by controlling the operation of the winding angle adjustment roll 134. Specifically, the control amount correction unit 62 adjusts the control amount that controls the operation of the winding angle adjustment roll 134 and outputs a corrected control amount. The control amount for controlling the operation of the winding angle adjustment roll 134 has a predetermined adjustment range set in advance, and the control amount correction unit 62 adjusts the control amount within the predetermined adjustment range. For example, it is preferable to prepare a map (matrix diagram) that defines the relationship between the transport speed of the single-sided corrugated cardboard sheet D, the control amount of heating, and the deviation ΔL.

[0102] Furthermore, the control amount correction unit 62 adjusts the control amount to reduce the tension of the back liner C when the inspection device 61 determines that the back liner C of the single-sided corrugated cardboard sheet D is a washboard. That is, as shown in Figure 1, when the back liners C1 and C2 are fed from the roll paper at the mill roll stands 12 and 16, the tension of the back liners C1 and C2 is set by activating the paper feed brake (not shown).

[0103] Therefore, in order to reduce the tension of the back liner C, the tension of the back liner C is reduced by controlling the operation of the paper feed brake. Specifically, the control amount correction unit 62 adjusts the control amount that controls the operation of the paper feed brake and outputs a corrected control amount. The control amount for controlling the operation of the paper feed brake has a predetermined adjustment range set in advance, and the control amount correction unit 62 adjusts the control amount within the predetermined adjustment range. For example, it is preferable to prepare a map (matrix diagram) that defines the relationship between the transport speed of the single-sided corrugated cardboard sheet D, the tension control amount, and the deviation ΔL.

[0104] In the above description, when the inspection device 61 determined that the back liner C of the single-sided corrugated cardboard sheet D was a washboard, the control amount 62 adjusted the control amount to reduce the amount of adhesive, reduce the amount of heating, or reduce the tension. The same processing is performed by the control amount correction unit 62 when the inspection device 61 determines that the back liner C or front liner A of the double-sided corrugated cardboard sheets E and F is a washboard. In this case, the control to reduce the amount of adhesive on the front liner A is performed by adjusting the control amounts of the meter rolls 107a and 107b (see Figure 4). Furthermore, the control to reduce the amount of heating on the front liner A is performed by adjusting the control amount of the heating section 36 (see Figure 1). In addition, the control to reduce the tension of the front liner A is performed by adjusting the control amount of the mill roll stand 19 (see Figure 1).

[0105] Furthermore, the control device 60 outputs the inspection results of the inspection device 61 to the display unit 54. The display unit 54 displays the inspection results of the inspection device 61 on a monitor. Figure 10 is a schematic diagram showing an example of the display of inspection results of the corrugated cardboard sheet inspection device. Figure 10 shows an example of the display of the display unit 54 while the corrugated machine 10 is in operation.

[0106] While the corrugated machine 10 is in operation, the inspection device 61 inspects the corrugated cardboard sheets, and the control device 60 displays the inspection results on the display unit 54 as a current display, as shown in Figure 10. The display unit 54 displays the changes in washboard amount and warp amount that occur over time. Washboard amount is the deviation ΔL between the maximum convex part (minimum value) and the maximum concave part (maximum value) on the back liner C (or front liner A) in the detection area DA (see Figure 7), and warp amount is the deviation ΔL between the maximum convex part (minimum value) and the maximum concave part (maximum value) on the back liner C (or front liner A) in the detection area DA1 (see Figure 8).

[0107] Figure 11 is a schematic diagram showing an example of the display of inspection results from a corrugated cardboard sheet inspection device. Figure 11 shows an example of the display on the display unit 54 while the corrugating machine 10 is stopped.

[0108] While the corrugating machine 10 is in operation, the inspection device 61 inspects the corrugated cardboard sheets, and the control device 60 stores the inspection results in the storage unit 53. As shown in Figure 11, the operator can check past inspection results as a trend display. The operator selects past inspection results using the operation unit 52. The control device 60 selects the inspection results stored in the storage unit 53 based on the command from the operation unit 52, and the control device 60 displays the inspection results on the display unit 54. The display unit 54 displays the changes in the amount of washboard and warping that occur over time, similar to when the corrugating machine 10 is in operation.

[0109] <Modifications of Detector Arrangement> In the embodiment described above, the first detector 71 was placed between the single facers 13, 17 and the double facer 22, and the second detector 72 was placed downstream of the double facer 22. However, the arrangement is not limited to this configuration. For example, only one detector may be placed between the single facers 13, 17 and the double facer 22, or only one detector may be placed downstream of the double facer 22. That is, since washboard tends to occur on the back liner C, only the back liner C may be detected by a single detector placed between the single facers 13, 17 and the double facer 22. Alternatively, only the back liner C may be detected by a single detector placed downstream of the double facer 22. In this case, the back liner C and the front liner A may be detected by two detectors placed downstream of the double facer 22.

[0110] By arranging two detectors 71 and 72 on the corrugating machine 10, it is possible to inspect corrugated cardboard sheets at different transport positions while the corrugating machine 10 is in operation and compare the amount of washboard (deviation ΔL) at different positions. Based on the comparison results of the amount of washboard (deviation ΔL) at different positions, the control amount can be adjusted.

[0111] Alternatively, as shown in Figure 3, the first detector 71 may be placed downstream of the single facers 13 and 17, and the second detector 72 (72Ca, 72Cb) may be placed outside the corrugating machine 10. The first detector 71 detects the back liner C and front liner A in the single-sided corrugated cardboard sheet D and the double-sided corrugated cardboard sheet E and F, while the second detector 72 measures the corrugated cardboard sheet F discharged from the corrugating machine 10. The second detector 72 is preferably placed in a temporary storage area for the corrugated cardboard sheet F or in the paper feeding device of the box-making machine. In this case, the detection results detected by the second detector 72 are stored in the storage unit 53. The detection results stored in the storage unit 53 are linked to the production management information stored in the production management device 56 at the time the corrugated cardboard sheet F was produced. Alternatively, an operator may operate the operation unit 52 to link the results with the production management information.

[0112] By placing a first detector 71 on the corrugating machine 10 and a second detector 72 outside the corrugating machine 10, it is possible to compare the amount of washboard (deviation ΔL) of the corrugated cardboard sheet while the corrugating machine 10 is in operation with the amount of washboard (deviation ΔL) of the corrugated cardboard sheet after a predetermined time has elapsed since operation. The control amount can be adjusted based on the comparison results of the amount of washboard (deviation ΔL) at different time points.

[0113] [Effects of this Embodiment] The corrugated cardboard sheet inspection device according to the first embodiment is a corrugated cardboard sheet inspection device 61 that inspects the surface shape of liners A and C in corrugated cardboard sheets D, E and F formed by bonding at least one flat liner A and C to a core B having a plurality of corrugated ridges in a wave shape, and comprises detectors 71 and 72 positioned on the surface side of liners A and C with respect to the transport line of corrugated cardboard sheets D, E and F and measuring the surface unevenness shape of liners A and C over a predetermined detection length in the transport direction of corrugated cardboard sheets D, E and F, and a calculation unit 73 that calculates the deviation between the maximum convex part and the maximum concave part in the surface unevenness shape of liners A and C based on the detection results of detectors 71 and 72.

[0114] According to the corrugated cardboard sheet inspection apparatus of the first embodiment, detectors 71 and 72 measure the surface irregularities of liners A and C over a predetermined detection length in the transport direction of corrugated cardboard sheets D, E, and F, and the calculation unit 73 calculates the deviation between the maximum protrusion and the maximum recess based on the surface irregularities of liners A and C. Even if the detectors 71 and 72 or the corrugated cardboard sheets D, E, and F vibrate, the detectors 71 and 72 measure the surface irregularities of liners A and C over the detection length, so the occurrence of errors between the maximum protrusion and the maximum recess used by the calculation unit 73 in the calculation is suppressed. As a result, the surface irregularities of liners A and C on corrugated cardboard sheets D, E, and F can be measured with high accuracy. Furthermore, since the measurement errors of detectors 71 and 72 are suppressed, there is no need to correct the measured values, and the complexity of the apparatus can be suppressed.

[0115] The corrugated cardboard sheet inspection apparatus according to the second embodiment is the same as the corrugated cardboard sheet inspection apparatus according to the first embodiment, and further, the detection length is greater than or equal to the length between adjacent corrugations in the transport direction of corrugated cardboard sheets D, E, and F. As a result, the detectors 71 and 72 measure the surface irregularities of liners A and C within the range between adjacent corrugations of the core B, and the calculation unit 73 can determine the maximum protrusion and maximum recess based on the surface irregularities of liners A and C and calculate the deviation with high accuracy.

[0116] The corrugated cardboard sheet inspection apparatus according to the third embodiment is a corrugated cardboard sheet inspection apparatus according to the first or second embodiment, wherein the detectors 71 and 72 are distance sensors that measure the distance from a mounting position located on the surface side of the liner A and C with respect to the transport line of the corrugated cardboard sheets D, E and F to the surface of the liner A and C, and simultaneously measure the distance to the surface of multiple liners A and C that are shifted in the transport direction of the corrugated cardboard sheets D, E and F between adjacent corrugations in the transport direction of the corrugated cardboard sheets D, E and F. As a result, the detectors 71 and 72 simultaneously measure multiple distances to different surfaces of the liner A and C within the range between adjacent corrugations of the core B, and the calculation unit 73 can determine the maximum convex and maximum concave using the multiple distances to different surfaces of the liner A and C, and calculate the deviation with high accuracy.

[0117] The corrugated cardboard sheet inspection apparatus according to the fourth embodiment is a corrugated cardboard sheet inspection apparatus according to any one of the first to third embodiments, wherein the calculation unit 73 calculates multiple deviations calculated between adjacent corrugations in the transport direction of corrugated cardboard sheets D, E, and F, and calculates an average deviation by averaging the multiple deviations. As a result, the calculation unit 73 can calculate the deviation between the maximum convex part and the maximum concave part with high accuracy.

[0118] The corrugated cardboard sheet inspection device according to the fifth embodiment is a cardboard sheet inspection device according to any one of the first to third embodiments, and further includes a determination unit 74 that determines that liners A and C are washboards if the deviation calculated by the calculation unit 73 exceeds a preset determination value. This makes it possible to appropriately detect washboards.

[0119] The corrugated cardboard sheet inspection apparatus according to the sixth embodiment is a corrugated cardboard sheet inspection apparatus according to the fifth embodiment, wherein the detectors 71 and 72 further measure the surface irregularities of liners A and C over a length of inclination detection in a direction inclined in the width direction of corrugated cardboard sheets D, E and F with respect to the transport direction of corrugated cardboard sheets D, E and F. This makes it possible to detect warping in the width direction of corrugated cardboard sheets D, E and F.

[0120] The corrugated cardboard sheet control device according to the seventh embodiment comprises a corrugated cardboard sheet inspection device 61 according to any one of the first to sixth embodiments, a control unit 63 that controls manufacturing equipment 51 for manufacturing corrugated cardboard sheets D, E, and F based on a preset control amount, and a control amount correction unit 62 that corrects the control amount based on the detection result of the corrugated cardboard sheet inspection device 61. As a result, the corrugated cardboard sheet inspection device 61 can measure the surface irregularities of liners A and C in corrugated cardboard sheets D, E, and F with high precision, and the control amount correction unit 62 can correct the control amount based on the detection result of the corrugated cardboard sheet inspection device 61, thereby improving the quality of the double-sided corrugated cardboard sheet F.

[0121] The corrugated cardboard sheet control device according to the eighth embodiment is a corrugated cardboard sheet control device according to the seventh embodiment, further, the control amount correction unit 62 adjusts the control amount to reduce the amount of adhesive used to bond the liners A and C to the core B when the deviation calculated by the calculation unit 73 by the corrugated cardboard sheet inspection device 61 exceeds a preset determination value and the unit determines that the liners A and C are washboards. By doing so, the amount of adhesive used to bond the liners A and C to the core B is reduced, thereby suppressing the occurrence of washboards and improving the quality of the double-sided corrugated cardboard sheet F.

[0122] The corrugated cardboard sheet control device according to the ninth embodiment is a corrugated cardboard sheet control device according to the seventh or eighth embodiment, further comprising a control amount correction unit 62 that, when the deviation calculated by the calculation unit 73 by the corrugated cardboard sheet inspection device 61 exceeds a preset determination value and the device determines that the liners A and C are washboards, adjusts the control amount to reduce the amount of heating required to heat the liners A and C. By reducing the amount of heating required to heat the liners A and C, the occurrence of washboards can be suppressed and the quality of the double-sided corrugated cardboard sheet F can be improved.

[0123] The corrugated cardboard sheet control device according to the tenth embodiment is a corrugated cardboard sheet control device according to any one of the seventh to ninth embodiments, and further, the control amount correction unit 62 adjusts the control amount to reduce the tension of liners A and C when the deviation calculated by the calculation unit 73 by the corrugated cardboard sheet inspection device 61 exceeds a preset judgment value and is determined to be a washboard. By doing so, the occurrence of washboards can be suppressed by reducing the tension of liners A and C, and the quality of the double-sided corrugated cardboard sheet F can be improved.

[0124] The corrugated cardboard sheet manufacturing apparatus according to the eleventh embodiment comprises single facers 13, 17 and double facer 22 (sheet laminating apparatus) that bond at least one flat liner A, C and a core B having a plurality of corrugated corrugations forming a wave shape to form corrugated cardboard sheets D, E, F, and a corrugated cardboard sheet inspection apparatus 61. As a result, the corrugated cardboard sheet inspection apparatus 61 can measure the surface irregularities of liners A, C in corrugated cardboard sheets D, E, F with high precision, thereby improving the quality of double-sided corrugated cardboard sheets F.

[0125] 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 single facers 13, 17 that manufacture single-sided corrugated cardboard sheets D by laminating a flat back liner (second liner) C and a corrugated core B, and a double facer 22 that manufactures double-sided corrugated cardboard sheets E, F by laminating a front liner (first liner) A to the core B of the single-sided corrugated cardboard sheet D, and the detector 71 is positioned between the single facers 13, 17 and the double facer 22. As a result, the corrugated cardboard sheet inspection apparatus 61 can inspect the back liner C immediately after it is attached to the core B, and can detect washboard at an early stage.

[0126] The corrugated cardboard sheet manufacturing apparatus according to the 13th embodiment is a corrugated cardboard sheet manufacturing apparatus according to the 11th or 12th embodiment, further comprising single facers 13, 17 that manufacture single-sided corrugated cardboard sheets D by laminating a flat back liner (second liner) C and a corrugated core B, and a double facer 22 that manufactures double-sided corrugated cardboard sheets E, F by laminating a front liner (first liner) A to the core B of the single-sided corrugated cardboard sheet D, and the detector 71 is positioned on a pick-up conveyor 28 located on the exit side of the single facers 13, 17. As a result, the corrugated cardboard sheet inspection apparatus 61 can inspect the back liner C immediately after it is attached to the core B, and can detect washboard at an early stage.

[0127] The corrugated cardboard sheet manufacturing apparatus according to the 14th embodiment is a corrugated cardboard sheet manufacturing apparatus according to any one of the 11th to 13th embodiments, further comprising single facers 13, 17 that manufacture single-sided corrugated cardboard sheets D by laminating a flat back liner (second liner) C and a corrugated core B, and a double facer 22 that manufactures double-sided corrugated cardboard sheets E, F by laminating a front liner (first liner) A to the core B of the single-sided corrugated cardboard sheet D, and the detector 72 is positioned downstream of the double facer 22. As a result, the corrugated cardboard sheet inspection apparatus 61 can inspect the back liner C that has been attached to the core B for a predetermined time and can detect washboards at an early stage. It can also inspect the front liner A immediately after it has been attached to the core B and can appropriately detect washboards.

[0128] The corrugated cardboard sheet manufacturing apparatus according to the 15th embodiment is a corrugated cardboard sheet manufacturing apparatus according to the 11th embodiment, further comprising single facers 13, 17 that manufacture single-sided corrugated cardboard sheets D by bonding a flat back liner (second liner) C and a corrugated core B, and a double facer 22 that manufactures double-sided corrugated cardboard sheets E, F by bonding a front liner (first liner) A to the core B of the single-sided corrugated cardboard sheet D, and a first detector 71 positioned downstream of the single facers 13, 17 in the transport direction of the corrugated cardboard sheets D, E, F, and a second detector 72 positioned downstream of the first detector 71 in the transport direction of the corrugated cardboard sheets E, F. As a result, the corrugated cardboard sheet inspection apparatus 61 can perform inspections on single-sided corrugated cardboard sheets D and double-sided corrugated cardboard sheets E, F, and can correct the control amount with high precision by comparing the inspection results for single-sided corrugated cardboard sheets D and double-sided corrugated cardboard sheets E, F.

[0129] The corrugated cardboard sheet manufacturing apparatus according to the 16th embodiment is a corrugated cardboard sheet manufacturing apparatus according to the 11th embodiment, further comprising single facers 13, 17 that manufacture single-sided corrugated cardboard sheets D by laminating a flat back liner (second liner) C and a corrugated core B, and a double facer 22 that manufactures double-sided corrugated cardboard sheets E, F by laminating a front liner (first liner) A to the core B of the single-sided corrugated cardboard sheet D, and a first detector 71 positioned downstream of the single facers 13, 17 in the conveying direction of the corrugated cardboard sheets D, E, F, and a second detector 72 that performs measurements on the double-sided corrugated cardboard sheets F discharged from the corrugating machine 10. As a result, the corrugated cardboard sheet inspection apparatus 61 can perform inspections on the corrugated cardboard sheets D, E, F and the double-sided corrugated cardboard sheet F, and can correct the control amount with high precision by comparing the inspection results for the corrugated cardboard sheets D, E, F and the inspection results for the double-sided corrugated cardboard sheet F.

[0130] The corrugated cardboard sheet manufacturing apparatus according to the 17th embodiment is a corrugated cardboard sheet manufacturing apparatus according to the 11th to 16th embodiments, and further includes a display unit 54 that displays the detection results of the corrugated cardboard sheet inspection device 61. This allows the operator to check the inspection results of the corrugated cardboard sheet inspection device 61 during or after the operation of the corrugating machine 10.

[0131] 10 Corrugated machine (cardboard sheet manufacturing equipment) 11, 12, 15, 16, 19 Mill roll stand 13, 17 Single facer (bonding equipment) 14, 18 Bridge 20 Preheater 21 Glue machine 22 Double facer (bonding equipment) 23 Rotary shaver 24 Slitter scorer 25 Cut-off 26 Defect removal equipment 27 Stacker 51 Manufacturing equipment 52 Operation unit 53 Memory unit 54 Display unit 55 Notification unit 56 Production management equipment 60 Control device (cardboard sheet control device) 61 Inspection device (cardboard sheet inspection device) 62 Control amount correction unit 63 Control unit 71, 71a, 71b, 71Aa, 71Ab, 71Ba, 71Bb, 71Ca, 71Cb First detector 72, 72a, 72b, 72Aa, 72Ab, 72Ba, 72Bb, 72Ca, 72Cb Second detector 73 Calculation unit 74 Judgment unit A Front liner B, B1, B2 Core C, C1, C2 Back liner D, D1, D2 Single-sided corrugated cardboard sheet (corrugated cardboard sheet) E, F Double-sided corrugated cardboard sheet (corrugated cardboard sheet)

Claims

1. A corrugated cardboard sheet inspection device for inspecting the surface shape of a liner in a corrugated cardboard sheet formed by bonding at least one flat liner and a core having a plurality of corrugated ridges, comprising: a detector positioned on the surface side of the liner with respect to the transport line of the corrugated cardboard sheet and measuring the surface unevenness shape of the liner over a predetermined detection length in the transport direction of the corrugated cardboard sheet; and a calculation unit that calculates the deviation between the maximum convex part and the maximum concave part in the surface unevenness shape of the liner based on the detection result of the detector.

2. The corrugated cardboard sheet inspection apparatus according to claim 1, wherein the detection length is greater than or equal to the length between adjacent corrugated cardboard ridges in the conveying direction of the corrugated cardboard sheet.

3. The corrugated cardboard sheet inspection apparatus according to claim 1, wherein the detector is a distance sensor that measures the distance from a mounting position located on the surface side of the liner with respect to the transport line of the corrugated cardboard sheet to the surface of the liner, and simultaneously measures the distance to the surface of a plurality of liners that are offset in the transport direction of the corrugated cardboard sheet between adjacent corrugated cardboard piles in the transport direction of the corrugated cardboard sheet.

4. The corrugated cardboard sheet inspection apparatus according to claim 1, wherein the calculation unit calculates a plurality of deviations calculated between adjacent corrugated cardboard piles in the transport direction of the corrugated cardboard sheet, and calculates an average deviation by averaging the plurality of deviations.

5. The corrugated cardboard sheet inspection apparatus according to claim 1, further comprising a determination unit that determines the liner is a washboard when the deviation calculated by the calculation unit exceeds a preset determination value.

6. The corrugated cardboard sheet inspection apparatus according to claim 1, wherein the detector measures the surface irregularities of the liner over a length of inclination detection in a direction inclined in the width direction of the corrugated cardboard sheet with respect to the transport direction of the corrugated cardboard sheet.

7. A corrugated cardboard sheet control device comprising: a corrugated cardboard sheet inspection device according to claim 1; a control unit that controls manufacturing equipment for manufacturing the corrugated cardboard sheet based on a preset control amount; and a control amount correction unit that corrects the control amount based on the detection result of the corrugated cardboard sheet inspection device.

8. The corrugated cardboard sheet control device according to claim 7, wherein the control amount correction unit adjusts the control amount to reduce the amount of adhesive used to bond the liner and the core when the deviation calculated by the calculation unit by the corrugated cardboard sheet inspection device exceeds a preset determination value and the liner is determined to be a washboard.

9. The corrugated cardboard sheet control device according to claim 7, wherein the control amount correction unit adjusts the control amount to reduce the amount of heating required to heat the liner when the deviation calculated by the calculation unit by the corrugated cardboard sheet inspection device exceeds a preset determination value and the liner is determined to be a washboard.

10. The corrugated cardboard sheet control device according to claim 7, wherein the control amount correction unit adjusts the control amount to reduce the tension of the liner when the deviation calculated by the calculation unit by the corrugated cardboard sheet inspection device exceeds a preset determination value and the device determines that the liner is a washboard.

11. A corrugated cardboard sheet manufacturing apparatus comprising: a sheet laminating apparatus for forming a corrugated cardboard sheet by laminating at least one flat liner and a core having a plurality of corrugated ridges; and a corrugated cardboard sheet inspection apparatus according to claim 1.

12. The corrugated cardboard sheet manufacturing apparatus according to claim 11, wherein the sheet laminating apparatus comprises a single facer that laminates a flat second liner and a corrugated core to produce a single-sided corrugated cardboard sheet, and a double facer that laminates a first liner to the core of the single-sided corrugated cardboard sheet to produce a double-sided corrugated cardboard sheet, and the detector is disposed between the single facer and the double facer.

13. The corrugated cardboard sheet manufacturing apparatus according to claim 11, wherein the sheet laminating apparatus comprises a single facer that laminates a flat second liner and a corrugated core to produce a single-sided corrugated cardboard sheet, and a double facer that laminates a first liner to the core of the single-sided corrugated cardboard sheet to produce a double-sided corrugated cardboard sheet, and the detector is located on a pick-up conveyor located on the exit side of the single facer.

14. The corrugated cardboard sheet manufacturing apparatus according to claim 11, wherein the sheet laminating apparatus comprises a single facer that laminates a flat second liner and a corrugated core to produce a single-sided corrugated cardboard sheet, and a double facer that laminates a first liner to the core of the single-sided corrugated cardboard sheet to produce a double-sided corrugated cardboard sheet, and the detector is arranged downstream of the double facer.

15. The corrugated cardboard sheet manufacturing apparatus according to claim 11, wherein the sheet laminating apparatus comprises a single facer that laminates a flat second liner and a corrugated core to produce a single-sided corrugated cardboard sheet, and a double facer that laminates a first liner to the core of the single-sided corrugated cardboard sheet to produce a double-sided corrugated cardboard sheet, and the detector comprises a first detector positioned downstream of the single facer in the transport direction of the corrugated cardboard sheet, and a second detector positioned downstream of the first detector in the transport direction of the corrugated cardboard sheet.

16. The corrugated cardboard sheet manufacturing apparatus according to claim 11, wherein the sheet laminating apparatus comprises a single facer that laminates a flat second liner and a corrugated core to produce a single-sided corrugated cardboard sheet, and a double facer that laminates a first liner to the core of the single-sided corrugated cardboard sheet to produce a double-sided corrugated cardboard sheet, and the detector comprises a first detector positioned downstream of the single facer in the conveying direction of the corrugated cardboard sheet, and a second detector that performs measurements on the corrugated cardboard sheet discharged from the corrugated cardboard sheet manufacturing apparatus.

17. The corrugated cardboard sheet manufacturing apparatus according to claim 11, further comprising a display unit for displaying the detection results of the corrugated cardboard sheet inspection apparatus.

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