Detection device, seat position adjustment device and corrugating machine

Abstract

To detect a real end part position in a width direction of a corrugated board sheet.SOLUTION: A detection device 10 detects an end part position in a width direction of a belt-like corrugated board sheet 5 when the corrugated board sheet 5 is being transported. The detection device 10 includes: measurement means 11, 21 that measure plural measurement point positions linearly arranged in the width direction in a measurement range including a predetermined measurement reference point and one end part in the width direction of the corrugated board sheet 5; and specifying means 22 that specifies, based on the plural measurement points measured, a real end part position in the width direction in a state in which the corrugated board sheet 5 is not bent. The specifying means 22 calculates respective distances between adjacent measurement points, calculates a sheet width length from the measurement reference point to the end part by adding all the distances, and specifies a position as the real end part position separated in the width direction from the measurement reference point by the sheet width length.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a detection device that detects the position of an edge of a cardboard sheet in the width direction, a sheet position adjustment device for a cardboard sheet, and a corrugating machine. [Background technology]

[0002] A corrugating machine is a device that transports a strip-shaped cardboard sheet made by laminating a liner and a core, and performs processes such as scoring, trimming, and cutting to produce the final product, cardboard for boxes. This corrugating machine measures the edge positions of the cardboard sheet in the width direction to ensure that the cardboard sheet is transported properly.

[0003] However, cardboard sheets may warp in the width direction during transport. When such warping occurs, if the edge position of the cardboard sheet is measured without taking the warping into account, a position shifted toward the center in the width direction from the original (true) edge position will be detected as the edge position of the cardboard sheet, making it impossible to accurately measure the true edge position. Furthermore, cardboard sheets may sway up and down during transport (so-called "fluttering"), causing a portion of the cardboard sheet to temporarily deform upward or downward compared to other portions. If the edge position of a cardboard sheet is measured while fluttering in this manner, a position shifted toward the center in the width direction from the original (true) edge position will be detected as the edge position of the cardboard sheet, just as in a case where the cardboard sheet is warped, making it impossible to accurately measure the true edge position. As a technique for accurately measuring warpage in the width direction, Patent Document 1 discloses a technique for measuring the true width of a plate material when the plate material is flat and free from warpage. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 63-184002 Summary of the Invention [Problem to be solved by the invention]

[0005] However, although the technology of Patent Document 1 can measure the true width of the plate, it cannot detect the true end position in an unwarped state. Therefore, even if the technology of Patent Document 1 is simply applied to a corrugating machine, there is a risk that, for example, the corrugated cardboard sheet may not be processed properly or conveyed properly.

[0006] The present invention was invented in view of the above-mentioned problems, and one of its objectives is to be able to detect the true edge position in the width direction of a cardboard sheet when the cardboard sheet is not warped. However, other objectives of the present invention are not limited to this objective, but also to achieve effects that cannot be obtained by conventional techniques, which are derived from the configurations shown in the following description of the preferred embodiment of the present invention. [Means for solving the problem]

[0007] (1) The present detection device is a detection device that detects the position of the edge of a strip-shaped cardboard sheet in the width direction while the cardboard sheet is being conveyed. The detection device includes a measuring means for measuring the positions of a plurality of measurement points in a linear line in the width direction within a measurement range that includes a predetermined measurement reference point in the width direction of the cardboard sheet and at least one of the edges in the width direction, and a device for determining the true edge position in the width direction when the cardboard sheet is not warped, based on the plurality of measurement points measured by the measuring means. The position considered to be The specifying means calculates the distance between each of the adjacent measurement points, calculates the sheet width length from the measurement reference point to the edge by adding up all the distances, and determines the position spaced apart from the measurement reference point in the width direction by the sheet width length as the true edge position. everyone and identified it.

[0008] (2) The sheet position adjustment device of the present invention includes the above-mentioned detection device, a calculation means for calculating the amount of deviation of the widthwise position of the cardboard sheet based on the true end position identified by the detection device and a reference position when transporting a strip-shaped cardboard sheet, and a correction means for correcting the widthwise position of the cardboard sheet based on the amount of deviation calculated by the calculation means. (3) The corrugating machine in this case is equipped with the above-mentioned sheet position adjustment device. [Effects of the Invention]

[0009] Even if the cardboard sheet is warped, the true edge position in the width direction of the cardboard sheet can be detected. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is an explanatory diagram of a detection device and a seat position adjustment device according to an embodiment of the present invention; [Figure 2] 2 is an explanatory diagram of a corrugating machine equipped with the detection device and the sheet position adjustment device of FIG. 1. [Figure 3] 2 is a diagram illustrating a detection range of a sensor included in the detection device of FIG. 1, viewed toward the downstream side in the conveying direction. FIG. [Figure 4] 1. FIG. 4 is an explanatory diagram showing the detection of the true edge position of a single-faced cardboard sheet in the detection device of FIG. [Figure 5] 5 is an explanatory diagram showing an enlarged view of the area including the second measurement reference point and the other end of the single-faced cardboard sheet of FIG. 4. FIG. [Figure 6] 10(a) to 10(c) are explanatory diagrams relating to widthwise position adjustment when the center position in the width direction of the front liner is set as the reference position. [Figure 7] 5(a) and 5(b) are explanatory diagrams relating to the control of the inclination of the shaft center of the meandering correction roll. [Figure 8] 10(a) to 10(c) are explanatory diagrams relating to widthwise position adjustment when the end position in the width direction of the front liner is set as the reference position. [Figure 9]10(a) to 10(c) are explanatory diagrams (corresponding to FIG. 4) relating to modified examples. [Figure 10] FIG. 10 is an explanatory diagram (corresponding to FIG. 4) relating to another modified example. [Figure 11] 1 is an explanatory diagram of a double-sided cardboard sheet detection device and a sheet position adjustment device. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0011] A detection device, a seat position adjustment device, and a corrugating machine will be described as embodiments with reference to the drawings. The embodiments described below are merely examples, and are not intended to exclude various modifications or applications of techniques not explicitly described in the following embodiments. Each configuration of the present embodiment can be modified in various ways without departing from the spirit of the invention. Furthermore, the configurations can be selected or combined as needed.

[0012] [1. Equipment configuration] Fig. 1 is an explanatory diagram of a detection device and a sheet position adjustment device according to this embodiment. The detection device and the sheet position adjustment device of Fig. 1 are installed in a corrugating machine. First, the configuration of a corrugating machine equipped with the detection device and the sheet position adjustment device will be outlined with reference to Figs. 2 and 3. In this specification, the conveying direction (MD in Figure 2) is the direction in which the cardboard is conveyed in the corrugating machine. The conveying direction corresponds to the longitudinal direction in which the band-shaped cardboard sheet extends. The width direction of the cardboard sheet (hereinafter simply referred to as the "width direction") corresponds to the machine width direction of the corrugating machine (CD in Figure 3). The direction perpendicular to both the longitudinal direction and the width direction is called the "height direction." The height direction corresponds to the up-down direction of the corrugating machine (TD in Figures 2 and 3).

[0013] 2 shows a corrugating machine 40. This corrugating machine 40 is a cardboard manufacturing device that produces a double-sided cardboard sheet by laminating a front liner and a back liner to both sides of a corrugating medium, and then performs processing such as scoring, trimming, and cutting on the double-sided cardboard sheet to produce the final product, cardboard for making boxes. Strip-shaped base paper (liner sheets) 4A, 4B, and 4C used for the back liner, corrugating medium, and front liner, respectively, are supplied to the corrugating machine 40 from mill roll stands 41A, 41B, and 41C. The mill roll stands 41A, 41B, and 41C are disposed adjacent to each other in this order from the upstream side to the downstream side in the conveying direction MD.

[0014] A single facer 42 is provided downstream of the mill roll stand 41A and adjacent to the upstream side of the mill roll stand 41B. The single facer 42 is supplied with base paper 4A for the back liner from the mill roll stand 41A and with base paper 4B for the core from the mill roll stand 41B. The single facer 42 steps and corrugates the core base paper 4B, and then attaches the back liner base paper 4A to the top of the corrugated core base paper 4B to form a strip-shaped single-faced cardboard sheet 5. The single-faced corrugated cardboard sheet 5 is a corrugated cardboard sheet in which a back liner is attached to one surface of a core.

[0015] A bridge 43 is disposed downstream of the single facer 42 and above the mill roll stands 41B and 41C. A double facer 46 is provided downstream of the mill roll stand 41C and the bridge 43 via a preheater 44 and a glue machine 45.

[0016] The bridge 43 is a bridge-like transport path for transporting the single-faced cardboard sheet 5 formed by the single facer 42 to the double facer 46. The bridge 43 functions as a retention section for temporarily retaining the single-faced cardboard sheet 5 in order to absorb the speed difference between the single facer 42 and the double facer 46.

[0017] The preheater 44 heats the single-faced cardboard sheet 5 conveyed from the bridge 43 and the base paper 4C for the front liner supplied from the mill roll stand 41C. The glue machine 45 glues the single-faced cardboard sheet 5 to the flute crests on the side opposite to the side where the back liner is pasted. The double facer 46 forms a double-sided corrugated cardboard sheet 5W by bonding a base paper 4C for a front liner to the single-sided corrugated cardboard sheet 5, and conveys the formed double-sided corrugated cardboard sheet 5W downstream. The double-sided corrugated cardboard sheet 5W is a cardboard sheet in which liners are bonded to both sides of a core.

[0018] A slitter scorer 47 and a cutoff 48 are disposed adjacent to each other in the conveying direction MD downstream of the double facer 46. While conveying the double-sided cardboard sheet 5W, the slitter scorer 47 and the cutoff 48 each sequentially perform processes such as scoring, trimming, and cutting on the double-sided cardboard sheet 5W being conveyed. In this way, the final product, the corrugated cardboard 5X for box making, is manufactured. The operation of this corrugating machine 40 is automatically controlled by a production management device (not shown).

[0019] Next, the configurations of the detection device 10 and the sheet position adjustment device 50 provided in the corrugating machine 40 will be described. The detector 10 detects the widthwise edge position of a cardboard sheet being conveyed, and is provided to identify the ideal widthwise edge position of a cardboard sheet without any warping (referred to as the "true edge position"). "Warping" refers to the upward or downward deformation of a portion of a cardboard sheet relative to the rest of the sheet. While cardboard sheets can warp in a planar fashion, the detector 10, which is fixed in position, detects the edge position of a cardboard sheet being conveyed (i.e., moving), and therefore the warping of the cardboard sheet is detected as a warp in the width direction of the cardboard sheet. However, the "warping" detected here also includes displacements resulting from temporary upward or downward deformation of a portion of the cardboard sheet relative to the rest of the sheet caused by the cardboard sheet swaying up and down during conveyance (so-called "fluttering").

[0020] The sheet position adjustment device 50 is a device that adjusts the widthwise position of a cardboard sheet, and in this embodiment in particular, it adjusts the widthwise position of the cardboard sheet being transported using the true end position identified by the detection device 10, and transports the cardboard sheet at an appropriate widthwise position. First, the configuration of the detection device 10 will be described, followed by the configuration of the sheet position adjustment device 50. Note that the cardboard sheets to be detected and conveyed by the detection device 10 and the sheet position adjustment device 50 are not limited to single-faced cardboard sheets 5, and therefore will also be referred to as "cardboard sheets 5" in the following description.

[0021] As shown in Fig. 1, the detection device 10 of this embodiment is attached to a conveying path 15 for a cardboard sheet 5 in a corrugating machine 40. This conveying path 15 is a route for conveying the cardboard sheet 5 from a bridge 43 to a preheater 44, and is installed above and in parallel with a conveying path 49 for conveying a base paper 4C for a front liner from a mill roll stand 41C to the preheater 44. This conveying path 15 is configured to include a plurality of conveying rolls.

[0022] The detection device 10 includes a sensor 11 (measuring means) that is arranged, for example, above and spaced apart from the cardboard sheet 5 being conveyed, and a control device 20. The sensor 11 is a detector for detecting the widthwise end position of the cardboard sheet 5 being transported along the transport path 15, and outputs position information including the widthwise position and heightwise position of the cardboard sheet 5 as a detection signal. A two-dimensional profile sensor is a specific example of the sensor 11 of this embodiment. The two-dimensional profile sensor is a laser displacement meter that irradiates the upper surface of the cardboard sheet 5 with laser light and outputs a detection signal based on the reflected light.

[0023] 3 is a diagram for explaining the detection range of the sensor 11, as viewed downstream in the conveying direction. The thick line in the figure indicates a cross-sectional view of the cardboard sheet 5 cut along the width direction. Note that the conveying path 15 and the corrugating machine 40 are omitted from FIG. 3.

[0024] As shown in FIG. 3, the sensor 11 of this embodiment is provided in multiple locations in the width direction. Specifically, the sensor 11 includes two sensors 11A and 11B (first measurement means and second measurement means). The sensors 11A and 11B are arranged adjacent to each other in the width direction of the conveying path 15. The first sensor 11A is provided to identify one end 32A of the cardboard sheet 5 in the width direction (hereinafter referred to as "one end 32A"). The second sensor 11B is arranged adjacent to the first sensor 11A on the other side in the width direction and is provided to identify the other end 32B of the cardboard sheet 5 in the width direction (hereinafter referred to as "other end 32B"). The two sensors 11A and 11B are identical to each other and differ only in their locations and the measurement ranges that accompany them. In the following description, when the two sensors 11A and 11B are not distinguished from each other, they will be collectively referred to as sensor 11.

[0025] As shown in FIG. 1, the sensor 11 is connected to the input side of the control device 20 , and the detection signal of the sensor 11 is input to the control device 20 . The control device 20 is an electronic control device configured as, for example, an LSI device or an embedded electronic device that integrates a microprocessor, ROM, RAM, etc. The control device 20 includes a measurement unit 21 (measurement means) and an identification unit 22 (identification means) as functional elements related to the detection device 10. These elements 21 and 22 represent some of the functions of a program executed by the control device 20, and may be realized by software, or some or all of the functions may be realized by hardware (electronic circuits), or may be realized by a combination of software and hardware.

[0026] As shown in FIG. 1, the seat position adjusting device 50 of this embodiment includes the above-mentioned detection device 10 and a meandering correction roll 16 (correction means). The meandering correction roll 16 is provided to adjust the widthwise position of the cardboard sheet 5 during transport, and is formed of a cylindrical rotating body with an axis 16A (see Figure 7(a)) extending in the widthwise direction. The meandering correction roll 16 is positioned at a height such that its outer circumferential surface contacts the upper surface of the cardboard sheet 5, and rotates around the axis 16A while contacting the upper surface of the cardboard sheet 5 during conveyance.

[0027] The meandering correction roll 16 is supported so that the inclination of the axis 16A relative to the width direction can be changed, and the width direction position of the cardboard sheet 5 being conveyed can be finely adjusted from one side to the other in the width direction or from the other side to one side depending on the inclination of the axis 16A. An actuator (not shown) is provided to change the inclination of the axis 16A of the meandering correction roll 16. The actuator of the meandering correction roll 16 is connected to the output side of the control device 20, and the actuator is controlled by the control device 20, whereby the inclination of the axis 16A of the meandering correction roll 16 is changed.

[0028] In this sheet position adjustment device 50, the widthwise position of the cardboard sheet 5 being conveyed is adjusted to match the reference position when the conveying path 15 conveys the cardboard sheet 5. The "reference position" here refers to the widthwise position that serves as the reference when the cardboard sheet 5 is conveyed on the conveying path 15.

[0029] In this embodiment, the reference position is, as an example, the central position in the width direction of the portion of the base paper 4C for the front liner just before it is pasted onto the single-faced cardboard sheet 5 (hereinafter, this portion will be referred to as the "front liner 4D"). The camera 17 provided above the conveying path 49 is a detector for detecting the central position in the width direction of the front liner 4D being conveyed on the conveying path 49. The camera 17 photographs the top surface of the front liner 4D being conveyed on the conveying path 49.

[0030] The camera 17 is connected to the input side of the control device 20 , and image data captured by the camera 17 is input to the control device 20 . The seat position adjusting device 50 of this embodiment further includes a position detecting unit 23, a deviation amount calculating unit 24 (calculating means), and a position correcting unit 25 (correcting means) provided within the control device 20 as functional elements related to the width direction position adjusting function of the seat position adjusting device 50. These elements 23, 24, and 25, like the above elements 21 and 22, also represent part of the functions of the program executed by the control device 20, and may be realized by software, hardware (electronic circuits), or a combination of these.

[0031] [2. Control configuration] Next, the units 21 to 25 provided as functional elements in the control device 20 will be described. First, the measurement unit 21 and the identification unit 22 provided as functional elements of the detection device 10 will be described.

[0032] The measurement unit 21 measures the positions of a plurality of measurement points in a linear fashion in the width direction within a predetermined measurement range in the width direction of the cardboard sheet 5 based on the output signal of the sensor 11. The measurement range is a range that includes a predetermined measurement reference point (described below) in the width direction of the cardboard sheet 5 and at least one end in the width direction. This measurement range is determined in advance based on the performance and arrangement of the sensor 11.

[0033] The positions of the multiple measurement points measured by the sensor 11 and the measurement unit 21 are position information expressed in XY coordinates, with the measurement reference point as the origin and, for example, the width direction of the cardboard sheet 5 as the X axis and the height direction as the Y axis. The XY coordinates are two-dimensional coordinates in which the position away from the measurement reference point in the width direction is the "X coordinate" and the position away from the measurement reference point in the height direction is the "Y coordinate."

[0034] As shown in Figure 3, two sensors 11A and 11B are used as an example to explain the respective measurement ranges 30A and 30B. The dashed lines in the figure represent the measurement ranges 30A and 30B, and the thick lines represent a cross section of the cardboard sheet 5 cut widthwise during transport. The black circles overlapping the thick lines represent measurement point P, and the white circles overlapping the thick lines represent measurement reference points 31A and 31B. The two-dot chain line in the figure represents an ideal cardboard sheet 5' with no warping.

[0035] 3, the measurement range 30A of the first sensor 11A is a range that includes the first measurement reference point 31A and one widthwise end 32A. The measurement range 30B of the second sensor 11B is a range that includes the second measurement reference point 31B and the other widthwise end 32B. Each sensor 11A, 11B is disposed so that the laser light irradiation range (measurement ranges 30A, 30B indicated by dashed lines in the figure) includes each measurement reference point 31A, 31B and each widthwise end 32A, 32B.

[0036] In each measurement range 30A, 30B, a plurality of measurement points P are set on a plane in the width direction. Specifically, the plurality of measurement points P are arranged in a linear line in the width direction in a plan view from each sensor 11A, 11B. More specifically, the plurality of measurement points P are arranged in a linear line in the width direction perpendicular to the conveyance direction of the cardboard sheet 5 in a plan view from each sensor 11A, 11B. The number of measurement points P in each measurement range 30A, 30B may be appropriately set depending on the specifications (performance, arrangement, etc.) of the sensors 11A, 11B, the processing capacity of the control device 20, etc., and is not particularly limited. From the viewpoint of improving measurement accuracy, a large number of measurement points P is preferable. Conversely, from the viewpoint of reducing the control load, it is preferable that the number of measurement points P is not too large, and the number is appropriately set taking these factors into consideration. Note that when two sensors 11A, 11B are provided, the numbers of measurement points P in the two measurement ranges 30A, 30B are set to be equal to each other. However, the number of measurement points P in the two measurement ranges 30A and 30B does not have to be equal.

[0037] Measurement reference points 31A and 31B are points (positions) used as references when measuring the widthwise end position of the cardboard sheet, and are predetermined as arbitrary positions in the machine width direction of the conveying path 15. The number of measurement reference points 31 is not particularly limited and may be equal to or greater than the number of sensors 11, or may be less than the number of sensors 11. In this embodiment, the number of measurement reference points 31 is the same as the number of sensors 11, i.e., one measurement reference point 31 is set for each sensor 11. Measurement reference points 31A and 31B are preferably set near the center in the width direction of the cardboard sheet 5, from the viewpoint that warping of the cardboard sheet 5 is less likely to occur and their positions are more stable. In the example shown in FIG. 3, the first measurement reference point 31A and the second measurement reference point 31B are set adjacent to each other near the center in the width direction of the cardboard sheet 5.

[0038] The actual positions of the ends 32A, 32B of the cardboard sheet 5 can be determined by the measuring unit 21 using well-known technology based on the output signal of the sensor 11. As shown in Figure 3, in the case of a cardboard sheet 5 in which warping has occurred in the area including both end portions 32A, 32B in the width direction, both end portions 32A, 32B are determined to be positions shifted toward the center in the width direction, as indicated by the two-dot chain lines in the figure, from the positions of both end portions 32A', 32B' of an ideal cardboard sheet 5' that is not warped. The measuring unit 21 expresses the position of each measurement point P in each of the measurement ranges 30A and 30B using XY coordinates, and outputs the XY coordinates indicating the position of each measurement point P to the identifying unit 22.

[0039] The identifying unit 22 identifies the true edge position in the width direction in an unwarped state based on the XY coordinates indicating the position of each measurement point P measured by the measuring unit 21. Note that the identifying unit 22 identifies the true edge position regardless of whether or not warping has occurred in the cardboard sheet 5. When the edge position of an unwarped cardboard sheet 5 is identified, the actual edge position and the true edge position coincide. The true end position identified by the identifying unit 22 is transmitted to the deviation amount calculating unit 24 and is used to adjust the width direction position of the cardboard sheet 5.

[0040] The identifying unit 22 has the following components A to C to identify the true end position. Configuration A: Based on the XY coordinates indicating the position of each measurement point P, adjacent measurement points P in the width direction Calculate the distance between each. Configuration B: By adding up the distances between all adjacent measurement points P, The sheet width up to the edge is calculated. Configuration C: The position separated from the measurement reference point in the width direction by the sheet width length is the true edge Identify it as a location.

[0041] FIG. 4 is an explanatory diagram for explaining the true end position based on the detection signals of the sensors 11A and 11B in FIG. The identification unit 22 calculates the distance between each adjacent measurement point P in the measurement range 30A, adds up all the distances, and calculates a first sheet width length l1 from the first measurement reference point 31A to one end 32A in the width direction. This first sheet width length l1 can be considered to be the sheet width length from the first measurement reference point 31A to one end 32A' of the ideal corrugated cardboard sheet 5'. Therefore, the identification unit 22 identifies a position linearly spaced from the first measurement reference point 31A toward the one end 32A in the width direction by the first sheet width length l1 as the position of one true end in the width direction.

[0042] Similarly, the determination unit 22 calculates the distance between adjacent measurement points P in the measurement range 30B and adds up all the distances to calculate a second sheet width length l2 from the second measurement reference point 31B to the other widthwise end 32B. This second sheet width length l2 can be considered to be the sheet width length from the second measurement reference point 31B to the other widthwise end 32B' of the ideal cardboard sheet 5'. Therefore, the determination unit 22 determines the position linearly spaced from the second measurement reference point 31B toward the other widthwise end 32B by the second sheet width length l2 as the other true widthwise end position.

[0043] A specific example of an arithmetic formula for calculating the sheet width length in the determination unit 22 will be described. Here, an example is given in which the second sheet width length l2 is calculated, but the first sheet width length l1 can also be calculated in the same way. Fig. 5 is an explanatory diagram showing an enlarged view of the area including the second measurement reference point 31B and the other end 32B on the cardboard sheet 5 of Fig. 4. In the figure, "(x1, y1)", "(x2, y2)", ..., "(x8, y8)" are the X and Y coordinates of each measurement point P (black circles, only one symbol is attached), "dx" is the distance between the X coordinates of adjacent measurement points P, and "dy" is the distance between the Y coordinates of adjacent measurement points P.

[0044] As shown in FIG. 5, when the second measurement reference point 31B is a parameter t=a and the other end 32B is a parameter t=b, the second sheet width length l2 can be calculated by the following formula 1.

number

[0045] Furthermore, since each of the measurement reference points 31A and 31B is predetermined as an arbitrary position in the machine width direction of the conveying path 15, the specifying unit 22 can specify the central sheet width length 10 between the two measurement reference points 31A and 31B. The specifying unit 22 can calculate the total sheet width L of the ideal corrugated cardboard sheet 5' by adding up the central sheet width l0, the first sheet width l1, and the second sheet width l2.

[0046] Next, the position detection unit 23, the deviation amount calculation unit 24, and the position correction unit 25, which are provided as functional elements related to the seat position adjustment device 50, will be described. The position detection unit 23 identifies the center position in the width direction of the front liner 4D based on the image data captured by the camera 17, and transmits the identified center position to the deviation amount calculation unit 24 as a reference position.

[0047] The deviation amount calculation unit 24 calculates the deviation amount of the widthwise position of the cardboard sheet 5 on the conveying path 15 based on the true end position identified by the identification unit 22 of the detection device 10 and the reference position transmitted from the position detection unit 23. The amount of deviation is a value (length in the width direction) indicating how much the cardboard sheet 5 is deviated in the width direction from the position where it should be conveyed on the conveying path 15. The deviation amount calculation unit 24 transmits the calculated amount of deviation to the position correction unit 25.

[0048] In this embodiment, the deviation amount calculation unit 24 uses the center position in the width direction of the front liner 4D as the reference position. In this case, the deviation amount calculation unit 24 identifies a virtual center position based on the true end positions, and compares the identified virtual center position with the reference position to calculate the deviation amount. The virtual center position is a position in the width direction of the cardboard sheet 5 being conveyed, and is the center position between the true end positions on both sides in the width direction.

[0049] The position correction unit 25 adjusts the widthwise position of the cardboard sheet 5 on the conveying path 15 based on the amount of deviation calculated by the deviation amount calculation unit 24. Since the sheet position adjustment device 50 of this embodiment is provided with the meandering correction roll 16, the position correction unit 25 outputs a control signal based on the amount of deviation to the actuator of the meandering correction roll 16, and changes the inclination of the axis 16A of the meandering correction roll 16.

[0050] 6(a) to 6(c) are explanatory diagrams for widthwise position adjustment when the center position in the width direction of the front liner 4D is set as the reference position 60, and are diagrams showing the cardboard sheet 5 as viewed from above. Note that only in FIG. 6(a) is a cross-sectional view along the width direction shown to illustrate the warping of the cardboard sheet 5. For convenience of explanation, the dashed dotted line in the figure is a line extending from the reference position 60 in the conveying direction MD. In an actual sheet position adjustment device 50, the cardboard sheet 5 is conveyed, so the reference position 60 varies depending on the longitudinal position of the cardboard sheet 5.

[0051] The cardboard sheet 5 shown in Figures 6(a) to 6(c) has warpage in the region including both widthwise ends 32A and 32B. More specifically, as shown by the thick solid line in Figure 6(a), the cardboard sheet 5 shown here has greater warpage in the region including the other widthwise end 32B than in the region including the one widthwise end 32A.

[0052] FIG. 6(a) shows a state in which the widthwise center position between both ends 32A, 32B is aligned with a reference position 60 indicated by a dashed line. The symbol K in the figure is a dimension line indicating the widthwise distance between both ends 32A, 32B. The reference position 60 is aligned with a position spaced "K / 2" away from each of both ends 32A, 32B toward the widthwise center. The detection device 10 described above identifies the true edge positions 32A', 32B' of the ends 32A, 32B of the cardboard sheet 5 shown in FIG. 6(a).

[0053] The dashed lines in Figure 6(b) are lines extending from the identified true edge positions 32A' and 32B' in the conveying direction MD, and the two-dot chain line in Figure 6(b) is a line extending from the virtual center position 61 determined from the true edge positions 32A' and 32B' in the conveying direction MD. The symbol L in the figure is a dimension line indicating the widthwise distance between the true edge positions 32A' and 32B'. This distance L can be considered the sheet width length of an ideal cardboard sheet 5'.

[0054] As described above, when warpage occurs, the positions of both end portions 32A, 32B are determined to be positions that are shifted toward the center in the width direction from the true end positions 32A', 32B'. Furthermore, when the magnitude of warpage differs between both end portions 32A, 32B in the width direction, as shown in Figure 6(b), when the center position between both end portions 32A, 32B is aligned with reference position 60, the reference position 60 and the virtual center position 61 are shifted in the width direction. The deviation calculation unit 24 calculates this deviation in the width direction as a deviation ΔL. The deviation ΔL represents the distance by which the virtual center position 61 is shifted in the width direction relative to the reference position 60.

[0055] Based on the deviation ΔL, the position correction unit 25 controls the inclination of the axis 16A of the meandering correction roll 16 so as to align the virtual center position 61 with the reference position 60. In the example shown in FIG. 6(b), the inclination of the axis 16A of the meandering correction roll 16 is controlled so that the cardboard sheet 5 moves to the left in the figure, and the reference position 60 and the virtual center position 61 are aligned. As a result, even if the cardboard sheet 5 is warped, the widthwise position of the cardboard sheet 5 is adjusted to the appropriate position by aligning the virtual center position 61 with the reference position 60, as shown in Figure 6(c).

[0056] 7(a) and 7(b) are explanatory diagrams illustrating the change in the inclination of the axis 16A of the meandering correction roll 16, and are plan views of the meandering correction roll 16 together with the cardboard sheet 5. As indicated by the arrow in FIG. 7(a), the axis 16A of the meandering correction roll 16 can swing about an axis extending in the height direction TD on the upper surface of the cardboard sheet 5, and the swinging changes the inclination of the axis 16A. The meandering correction roll 16 in FIG. 7(a) is in a state where its axis 16A is not tilted (aligned with the cross machine direction CD). FIG. 7(b) shows an example of a state where the axis 16A of the meandering correction roll 16 is tilted. "Tilting the axis 16A" means setting an angle (inclination angle) of the axis 16A of the meandering correction roll 16 relative to the cross machine direction CD.

[0057] 7(a), the direction of the axis 16A coincides with the width direction. In this case, the cardboard sheet 5 is conveyed straight downstream in the conveying direction MD. 7(b), the cardboard sheet 5 is conveyed downstream in the conveying direction MD while the widthwise position of the cardboard sheet 5 is finely adjusted in the direction of arrow A according to the inclination of the cardboard sheet 16A. In this way, the meandering of the cardboard sheet 5 in the widthwise direction is corrected.

[0058] [3. Actions and Effects] (1) In the detection device 10 of this embodiment, the sensors 11A, 11B (sensor 11) and the measurement unit 21 measure a plurality of measurement points P from the measurement reference points 31A, 31B to the widthwise ends 32A, 32B of the cardboard sheet 5 using XY coordinates with the measurement reference points 31A, 31B as the origin. The identification unit 22 then adds up all the distances between adjacent measurement points among the plurality of measurement points P to calculate the sheet width length from the measurement reference points 31A, 31B to the ends 32A, 32B, and identifies a position spaced apart in the widthwise direction from the measurement reference points 31A, 31B by the sheet width length. These positions can be regarded as the true edge positions 32A', 32B' of an ideal, unwarped cardboard sheet 5'. Therefore, even if the cardboard sheet 5 is warped, the true edge positions 32A', 32B' in the width direction can be detected.

[0059] As a result, for example, in the corrugating machine 40, the cardboard sheet 5 can be appropriately processed and appropriately conveyed based on the true end positions 32A', 32B'. To give a specific example, if the cardboard sheet 5 is conveyed in a meandering manner, by detecting the true end positions 32A', 32B', the cardboard sheet 5 can be conveyed after appropriately correcting the meandering in consideration of the warp. Therefore, even when forming a corrugated cardboard from the corrugated cardboard sheet 5, the corrugated cardboard can be formed properly. Furthermore, the conventional technology for detecting the true board width described in Patent Document 1 cannot detect the true edge position when there is no warping, and therefore cannot properly adjust the shift in the width direction of the cardboard sheet 5 during transport. In contrast, the detection device 10 described above is advantageous over the conventional technology in that it can properly form cardboard from the cardboard sheet 5 in the corrugating machine 40.

[0060] (2) In the above-described detection device 10, two sensors 11A and 11B are arranged adjacent to each other in the width direction, so that one true edge position 32A' can be identified by measuring the measurement range 30A including one edge 32A with one sensor 11A, and the other true edge position 32B' can be identified by measuring the measurement range 30B including the other edge 32B with the other sensor 11B. Therefore, the true edge positions 32A' and 32B' can be detected with high accuracy for each of the end portions 32A and 32B of the cardboard sheet 5.

[0061] Furthermore, when determining the positions of both ends 32A, 32B using one sensor 11, it is necessary to devise an arrangement so that both ends 32A, 32B are included in the measurement range 30 of one sensor 11, or to use a sensor with a wide laser light irradiation range (measurement range); however, by providing dedicated sensors 11A, 11B for each end 32A, 32B, the measurement ranges 30A, 30B and the degree of freedom in arrangement of the sensors 11A, 11B can be increased.

[0062] (3) In the sheet position adjustment device 50, the deviation amount calculation unit 24 uses the true end positions 32A', 32B' identified by the detection device 10 to calculate the deviation amount, which indicates how much the cardboard sheet 5 is deviated in the width direction from the position where it should be conveyed. The position correction unit 25 adjusts the width direction position of the cardboard sheet 5 based on the calculated deviation amount in addition to the reference position 60 when the conveying path 15 conveys the cardboard sheet 5. Therefore, even if the cardboard sheet 5 is warped, it can be conveyed appropriately in accordance with the reference position 60.

[0063] (4) The above-mentioned amount of deviation is calculated by comparing a virtual center position 61 based on the true end positions 32A', 32B' with a reference position 60 based on the center position in the width direction of the front liner 4D to be bonded to the single-faced corrugated cardboard sheet 5. Therefore, when the width direction position of the single-faced corrugated cardboard sheet 5 is adjusted using this virtual center position 61, the single-faced corrugated cardboard sheet 5 can be properly transported relative to the front liner 4D, and deviation when bonding the single-faced corrugated cardboard sheet 5 to the front liner 4D can be suppressed.

[0064] (5) By providing the above-described detection device 10, the corrugating machine 40 can detect the true edge positions 32A', 32B' when the cardboard sheet 5 is flattened and uncurled, even if the cardboard sheet 5 is warped. The sheet position adjustment device 50 can then adjust the widthwise position of the cardboard sheet 5 based on the true edge positions 32A', 32B'. This allows the cardboard sheet 5 to be transported properly. This allows the corrugating machine 40 to process the cardboard sheet 5 properly.

[0065] [4. Other] The above-described embodiments are merely examples, and the configurations of the above-described embodiments may be selected as needed, or may be appropriately combined with various configurations included in known techniques.

[0066] In the sheet position adjustment device 50 of the embodiment described above, the center position in the width direction of the front liner 4D is set as the reference position 60. However, for example, one end position in the width direction of the front liner 4D may be set as the reference position. In this case, the position detection unit 23 identifies the position of one end in the width direction of the front liner 4D (liner sheet) based on image data captured by the camera 17, and transmits the identified one end position as the reference position to the deviation amount calculation unit 24. The deviation amount calculation unit 24 compares the true end position transmitted from the identification unit 22 with the reference position transmitted from the position detection unit 23 to calculate the deviation amount.

[0067] 8(a) to 8(c) are explanatory diagrams relating to widthwise position adjustment when the end position in the widthwise direction of the front liner 4D is set as the reference position 70, and correspond to FIGS. 6(a) to 6(c). Note that only in FIG. 8(a) is a cross-sectional view along the widthwise direction shown to illustrate the warping of the cardboard sheet 5. For ease of explanation, the dashed-dotted line in the figure is a line extending from the reference position 70 in the conveying direction MD. As with FIGS. 6(a) to 6(c), the cardboard sheet 5 shown in FIGS. 8(a) to 8(c) also has warping in the region including both widthwise ends 32A and 32B.

[0068] Fig. 8(a) shows a state in which the position of the other end 32B is aligned with the reference position 70 indicated by the dashed line. The dashed lines in Fig. 8(b) are lines extending in the conveying direction MD from the identified true end positions 32A', 32B', and the two-dot chain line in Fig. 8(b) is a line extending in the conveying direction MD from the other true end position 32B' used for position adjustment. In the seat position adjusting device 50 of this modified example, the deviation amount calculation unit 24 calculates the deviation in the width direction of the other true end position 32B' relative to the reference position 70 as the deviation amount ΔL'.

[0069] Based on the deviation ΔL′, the position correction unit 25 of this modified example controls the inclination of the axis 16A of the meandering correction roll 16 so as to align the other true end position 32B′ with the reference position 70. In the example shown in FIG. 8(b), the inclination of the axis 16A of the meandering correction roll 16 is controlled so that the cardboard sheet 5 moves to the left in the drawing, and the reference position 70 and the other true end position 32B′ are aligned. As a result, even if the cardboard sheet 5 is warped, as shown in Fig. 8(c), the widthwise position of the cardboard sheet 5 is adjusted to the appropriate position where the true edge position 32B' is aligned with the reference position 70. With the sheet position adjustment device 50 according to this modified example, the same effects as those of the above-described embodiment can be obtained.

[0070] Furthermore, warping of the cardboard sheet 5 does not necessarily occur in the region including both widthwise ends 32A, 32B. Figures 9(a) to 9(c) and 10 show modified examples of warping, which are common to Figure 4 except for the shape of the warping.

[0071] 9(a) shows an example of a shape in which a cardboard sheet 80 is warped all over from both widthwise ends 32A, 32B to the widthwise center. Also, FIG. 10 shows an example of a shape in which a part of a region 82 located between the other end 32B of a cardboard sheet 81 and the widthwise center is raised more than other parts.

[0072] The identification unit 22 can calculate the first sheet width length l1, the second sheet width length l2, and the central sheet width length l0 in both the cardboard sheet 80 of Fig. 9(a) and the cardboard sheet 81 of Fig. 10 using the same method as in the above-described embodiment, and identify the true edge positions 32A', 32B'. In this way, the above-described detection device 10 can identify and detect the true edge positions regardless of the warp shape of the cardboard sheet 5.

[0073] 9(b) is the same as FIG. 9(a) except that one measurement reference point 31C is set for two sensors 11A and 11B. In this case, one sensor 11A and measurement unit 21 measure multiple measurement points P from measurement reference point 31C to one end 32A, and the other sensor 11B and measurement unit 21 measure multiple measurement points P from measurement reference point 31C to the other end 32B. The determination unit 22 calculates the first sheet width length l1 from the measurement reference point 31C to one end 32A and the second sheet width length l2 from the measurement reference point 31C to the other end 32B, and can determine the total sheet width length L of the ideal cardboard sheet 5' and the true end positions 32A', 32B'.

[0074] FIG. 9(c) is the same as FIG. 9(a) except that the measurement range 30C of the sensor 11A (one of the two sensors 11A, 11B) is expanded to a range that includes both measurement reference points 31A and 31B. In this case, one sensor 11A and measurement unit 21 measure multiple measurement points P from the measurement reference point 31A to one end 32A and multiple measurement points P between the measurement reference point 31A and the measurement reference point 31B, and the other sensor 11B and measurement unit 21 measure multiple measurement points P from the measurement reference point 31B to the other end 32B. The determination unit 22 calculates the first sheet width length l1 and the central sheet width length l0 using one of the sensor 11A and multiple measurement points P measured by the measurement unit 21, and calculates the second sheet width length l2 using the other of the sensor 11B and multiple measurement points P measured by the measurement unit 21, thereby determining the total sheet width length L of the ideal cardboard sheet 5' and the true end positions 32A', 32B'.

[0075] As a modification of Figure 9(c), the measurement ranges of both sensors 11A and 11B may be widened to include both measurement reference points 31A and 31B. In Figure 9(c), the measurement range of sensor 11B widened to include both measurement reference points 31A and 31B is shown by a dashed line. In this case, one sensor 11A and measurement unit 21 measure multiple measurement points P from the measurement reference point 31A to one end 32A and multiple measurement points P between the measurement reference point 31A and the measurement reference point 31B, while the other sensor 11B and measurement unit 21 measure multiple measurement points P from the measurement reference point 31B to the other end 32B and multiple measurement points P between the measurement reference point 31A and the measurement reference point 31B.

[0076] The determination unit 22 calculates a first sheet width length l1 and a central sheet width length l0 using the multiple measurement points P measured by one sensor 11A and the measurement unit 21, and calculates a second sheet width length l2 and a central sheet width length l0 using the multiple measurement points P measured by the other sensor 11B and the measurement unit 21. Examples of methods for determining one of the two overlappingly calculated central sheet width lengths l0 include a method of using the average of both, a method of using the longer distance between both, or a method of using the shorter distance between both. The method to be used may be determined as appropriate.

[0077] Furthermore, the calculation formula for calculating the sheet width length in the specifying unit 22 is not limited to the above formula 1, and any known calculation formula for calculating the length of a curve can be used. For example, the curve connecting measurement reference point 31A (31B) and its adjacent end 32A (32B) is expressed as y = f(x), with measurement reference point 31A (31B) at x = a and end 32A (32B) at x = b. The length L of the curve expressed by y = f(x) can be calculated using the following equation 2.

number

[0078] Furthermore, if the curve connecting measurement reference point 31A (31B) and end 32A (32B) is a curve represented in polar coordinates as r=1+cosθ, the length L of the curve connecting measurement reference point 31A (31B) and end 32A (32B) can be calculated using the following equation 3.

number

[0079] In the above-described embodiment, an example was given in which the multiple measurement points P in each measurement range 30A, 30B are set in a straight line in the width direction perpendicular to the conveying direction of the cardboard sheet 5, but the setting of the multiple measurement points P is not limited to this. For example, the line connecting the multiple measurement points P in each measurement range 30A, 30B may be a line extending in the width direction at a predetermined angle with respect to the conveyance direction of the cardboard sheet 5. Alternatively, the line connecting the multiple measurement points P in measurement range 30A and the line connecting the multiple measurement points P in measurement range B may extend in the width direction at different angles with respect to the conveyance direction of the cardboard sheet 5; in other words, the multiple measurement points P do not have to be set in a straight line in measurement ranges 30A, 30B.

[0080] Furthermore, the detection device 10 is not limited to a configuration including two sensors 11A, 11B, but may be a configuration including three or more sensors. In this case, the sensor 11 and measurement unit 21 located at the widthwise end of the cardboard sheet 5 measure multiple measurement points P from an arbitrary measurement reference point to the widthwise end of the cardboard sheet 5. Furthermore, the sensor 11 and measurement unit 21 located closer to the widthwise center of the cardboard sheet 5 measure multiple measurement points P between the arbitrary measurement reference points.

[0081] The identification unit 22 calculates the sheet width length using multiple measurement points P measured by the sensor 11 and measurement unit 21 located at the widthwise edge of the cardboard sheet. The sheet width length is also calculated using multiple measurement points P measured by the sensor 11 and measurement unit 21 located closer to the widthwise center of the cardboard sheet 5. In this way, the ideal total sheet width length L of the cardboard sheet and the true edge position can be identified. A configuration with three or more (multiple) sensors 11 in the width direction enables more accurate measurements than a configuration with two or fewer sensors 11, and therefore the true edge position can be determined with high accuracy.

[0082] Furthermore, the detection device 10 is not limited to a configuration including two sensors 11A and 11B, and may be configured to include only one sensor 11. In this case, the detection device 10 may be configured to identify either one end position of the cardboard sheet 5 in the width direction using one sensor 11, or may be configured to identify both end positions of the cardboard sheet 5 in the width direction using one sensor 11.

[0083] The reference position when conveying the single-faced cardboard sheet 5 on the conveying path 15 is not limited to the position in the width direction of the front liner 4D, but may be a position based on the machine width direction CD of the conveying path 15. The cardboard sheets that are the target of the above-mentioned detection device 10 and sheet position adjustment device 50 are not limited to single-faced cardboard sheets, but may be any cardboard sheet such as liner sheets, double-faced cardboard sheets, or multi-faced cardboard sheets.

[0084] 11 is an explanatory diagram of a detection device 10W and a sheet position adjustment device 50W for identifying the true end position in the width direction of a double-sided cardboard sheet 5W. The detection device 10W and the sheet position adjustment device 50W in FIG. 11 are installed in the corrugating machine 40 in FIG. 2. In the detection device 10W of Fig. 11, the sensor 11W is provided downstream of the double facer 46 (see Fig. 2) and upstream of the slitter scorer 47, and is the same as the sensor 11 of Fig. 1 except that it detects the edge position in the width direction of the double-sided corrugated cardboard sheet 5W. The functional elements of the detection device 10W are the same as the measurement unit 21 and the identification unit 22 described above with reference to Fig. 1.

[0085] In the sheet position adjustment device 50W of Figure 11, the meandering correction roll 16W is located downstream of the double facer 46 and upstream of the slitter scorer 47, and is the same as the meandering correction roll 16 of Figure 1 except that it adjusts the widthwise position of the double-sided cardboard sheet 5W. In the sheet position adjusting device 50W, the widthwise position of the double-sided corrugated cardboard sheet 5W is adjusted so as to match the double-sided corrugated cardboard sheet 5W with a reference position when being conveyed.

[0086] An example can be given of a case where the reference position in the sheet position adjustment device 50W is the center position in the machine width direction CD of the corrugating machine 40. Specifically, the center position in the machine width direction CD is the center position in the machine width direction CD of the conveying path along which the double-sided corrugated cardboard sheet 5W is conveyed. This center position is preset as a position corresponding to the center position in the width direction of an ideal, uncurled double-sided corrugated cardboard sheet when it is conveyed without meandering. The deviation amount calculation unit 24 (see FIG. 1) and the position correction unit 25 (see FIG. 1) are the same as those described above, except that the reference position is the center position in the machine width direction CD of the corrugating machine 40. Therefore, the inclination of the axis 16A of the meandering correction roll 16W is controlled based on the deviation amount calculated using the true end position, and even if the double-sided corrugated cardboard sheet 5W is warped, meandering during conveyance can be corrected and the sheet can be conveyed properly.

[0087] As another example of the reference position in the sheet position adjusting device 50W of FIG. 11, one end position in the machine width direction CD of the corrugating machine 40 can be used. Specifically, the one end position in the cross machine direction CD is the end position of either one of the two ends of the conveying path along which the double-sided cardboard sheet 5W is conveyed in the cross machine direction CD. This end position is predetermined as a reference position, which is the end position of either one of the two ends of an ideal, uncurled double-sided cardboard sheet conveyed without meandering. The deviation amount calculation unit 24 (see FIG. 1) and the position correction unit 25 (see FIG. 1) are the same as those described above, except that the reference position is the one end position of the corrugating machine 40 in the cross machine direction CD. Therefore, the inclination of the axis 16A of the meandering correction roll 16W is controlled based on the deviation amount calculated using the true end position, and even if the double-sided cardboard sheet 5W is warped, meandering during conveyance can be corrected and the sheet can be conveyed properly.

[0088] In the embodiment shown in FIG. 11, the meandering correction method involves controlling the inclination of the axis 16A of the meandering correction roll 16W based on the amount of deviation calculated using the true edge position of the double-sided cardboard sheet 5W to correct meandering during conveyance. However, the meandering correction method is not limited to this. For example, the widthwise position of a processing device (not shown) provided in the slitter scorer 47 may be adjusted based on the amount of deviation calculated using the true edge position of the double-sided cardboard sheet 5W. Here, the processing device is a device whose position in the widthwise direction relative to the double-sided cardboard sheet 5W is adjustable. Specific examples of the processing device include a slitter knife for cutting the double-sided cardboard sheet 5W along the conveyance direction, a creasing roll for forming creasing lines on the double-sided cardboard sheet 5W, a cutting tape device for applying cutting tape to the double-sided cardboard sheet 5W, and a perforation blade for forming perforations in the double-sided cardboard sheet 5W. Adjusting the widthwise position of the processing device allows the double-sided cardboard sheet 5W to be processed to the appropriate widthwise position. [Explanation of symbols]

[0089] 4A Back liner base paper 4B core base paper 4C base paper for front liner 4D outer liner (liner sheet) 5. Single-sided corrugated cardboard sheets (corrugated cardboard sheets) 5W double-sided corrugated cardboard sheet 5X cardboard 10,10W detector 11,11W Sensor (Means of Measurement) 11A First sensor (first measuring means) 11B second sensor (second measuring means) 15 Transport path 16,16W Meandering correction roll (correction means) 16A shaft center 17 Camera 20 Control device 21 Measuring part (measuring means) 22 Specification part (specification means) 23 Position detection unit 24. Deviation amount calculation unit (calculation means) 25 Position correction section (correction means) 30, 30A, 30B measurement range 31A First measurement point 31B Second measurement reference point 32A One end (one end in the width direction) 32B other end (other end in width direction) 32A' One true end position 32B' The other true end position 40 Corrugating Machine 41A, 41B, 41C Mill Roll Stand 42 Single Facer 43 Bridge 44 Preheater 45 Glue Machine 46 Double Facer 47 Slitta Scorara 48 Cutoff 49 Transport Path 50,50W seat position adjustment device 60 Reference position 61 Virtual center position 70 Reference position 80,81 Corrugated cardboard sheet 82 Prominence ΔL, ΔL' deviation amount CD machine width direction MD conveying direction TD height direction (up and down direction)

Claims

1. A detection device that detects the position of an end of a strip-shaped cardboard sheet in the width direction while the cardboard sheet is being conveyed, A measuring means for measuring the positions of a plurality of measurement points in a linear shape in the width direction within a measurement range including a predetermined measurement reference point in the width direction of the cardboard sheet and at least one end in the width direction; and a means for determining a position that is considered to be a true end position in the width direction of the cardboard sheet when the cardboard sheet is not warped, based on the plurality of measurement points measured by the measuring means; The specifying means calculates the distance between each of the adjacent measurement points, calculates the sheet width length from the measurement reference point to the edge by adding up all the distances, and specifies a position spaced apart from the measurement reference point in the width direction by the sheet width length as the true edge position. A detection device comprising:

2. The measuring means is provided in plurality in the width direction.

2. The detection device according to claim 1, wherein the detection device comprises:

3. The measuring means includes a first measuring means for identifying one end in the width direction, and a second measuring means arranged adjacent to the first measuring means on the other side in the width direction, for identifying the other end in the width direction of the cardboard sheet.

3. The detection device according to claim 1 or 2, characterized in that:

4. A detection device according to any one of claims 1 to 3; A calculation means for calculating the amount of deviation of the width direction position of the cardboard sheet based on the true end position identified by the detection device and a reference position when conveying the strip-shaped cardboard sheet; and a correction means for correcting the width direction position of the cardboard sheet based on the amount of deviation calculated by the calculation means. A seat position adjusting device comprising:

5. The cardboard sheet is a single-faced cardboard sheet, The reference position is the center position in the width direction of the liner sheet to be attached to the single-faced cardboard sheet, The calculation means determines a virtual center position in the width direction of the single-faced cardboard sheet based on the true edge position, and calculates the amount of deviation by comparing the determined virtual center position with the reference position.

5. The seat position adjusting device according to claim 4.

6. The cardboard sheet is a single-faced cardboard sheet, The reference position is the position of one end in the width direction of the liner sheet to be bonded to the single-faced cardboard sheet, The calculation means calculates the amount of deviation by comparing the true end position of one of the single-faced cardboard sheets in the width direction with the reference position.

5. The seat position adjusting device according to claim 4.

7. The cardboard sheet is a double-sided cardboard sheet, The reference position is a central position in the machine width direction of a corrugating machine that produces the double-sided cardboard sheet, The calculation means determines a virtual center position in the width direction of the double-sided corrugated cardboard sheet based on the true edge position, and calculates the amount of deviation by comparing the determined virtual center position with the reference position.

5. The seat position adjusting device according to claim 4.

8. The cardboard sheet is a double-sided cardboard sheet, The reference position is one end position in the machine width direction of a corrugating machine that produces the double-sided cardboard sheet, The calculation means calculates the amount of deviation by comparing the true end position of one of the two-sided corrugated cardboard sheets in the width direction with the reference position.

5. The seat position adjusting device according to claim 4.

9. A seat position adjusting device according to any one of claims 4 to 8 is provided. The corrugating machine is characterized by:

Images