Overturn risk calculation method of coil, overturn suppression method of coil and overturn risk calculation device of coil

Abstract

To provide an overturn risk calculation method of a coil which can calculate an overturn risk of an object coil to be determined laid on a fixed skid where a side face thereof adjoiningly faces a side face of an object coil to be transferred.SOLUTION: An overturn risk calculation method of a coil calculating, when transferring an object coil to be transferred through a coil truck with a movable skid from a fixed skid where side faces of the object coil to be transferred and an object coil to be determined face each other to be laid, an overturn risk of an object coil to be determined comprises: a measurement step of measuring a distance between the side face of the object coil to be transferred and the side face of the object coil to be determined in the middle of lifting the object coil to be transferred by the movable skid; and an overturn risk specification step which specifies an overturn risk of the object coil to be determined by use of the distance.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a method for calculating the risk of coil tipping, a method for suppressing coil tipping, and an apparatus for calculating the risk of coil tipping.

Background Art

[0002] Metal strip coils such as wide steel strips may be cut (slit) into a plurality of strips in the width direction according to subsequent products, and made into slit coils with a narrower width than the original steel strip. In a slitter line for slitting a metal strip coil, while continuously conveying the metal strip coil, it is cut along the conveying direction using a slit blade. The metal strip coil cut by the slit blade is wound by a winder (tension reel) in an adjacent state. The metal strip coils wound in the slitter line are once placed on a fixed skid in a state where a plurality of metal strip coils are adjacent to each other with their sides facing each other.

[0003] The plurality of metal strip coils placed on the fixed skid are separated and carried out by a carrying-out device for use in the next process. At this time, as the carrying-out device, when the width of the slit metal strip coil is narrow, a carrying-out device that lifts and carries out the metal strip coil is used. On the other hand, when the width of the slit metal strip coil is relatively wide, a coil carriage is often used as the carrying-out device.

[0004] The coil carriage has a carriage body that travels on a track and a movable skid that raises and lowers the metal strip coil. In this case, after aligning the position of the movable skid of the coil carriage according to the divided state of the metal strip coil placed on the fixed skid, the movable skid is raised.

[0005] When raising the movable skid, if the position of the movable skid with respect to the metal strip coil shifts, the metal strip coil may fall over. In particular, when a metal strip coil slit on the fixed skid is placed adjacent to it, the movable skid may come into contact with the metal strip coil placed adjacent to the metal strip coil to be unloaded, and the adjacent metal strip coil may fall over.

[0006] When the metal strip coil falls over, it takes time to reload the metal strip coil onto the coil carriage again, resulting in a decrease in work efficiency. In addition, when the metal strip coil falls over, defects may occur on the metal strip coil, resulting in a decrease in product yield.

[0007] In particular, when a metal strip coil slit on the fixed skid is placed adjacent to it, the movable skid may come into contact with the metal strip coil placed adjacent to the metal strip coil to be unloaded, and the adjacent metal strip coil may fall over.

[0008] Regarding the problem of the metal strip coil falling over, Patent Document 1 discloses a method for preventing the coil from falling over when unloading by a coil carriage for a single metal strip coil. According to Patent Document 1, it is possible to prevent the coil from falling over by detecting the amount of displacement of the coil in the width direction from the reference position of the coil loading surface on the coil carriage on which the coil is loaded and traveled, and stopping the coil carriage when the detected amount of displacement is different from the initial amount of displacement.

[0009] Patent Document 2 discloses a method for preventing the coil from falling over when unloading by a coil carriage for narrow-width coils cut into a plurality of strips in a slitter line. According to Patent Document 2, it is possible to prevent the coil from falling over by using a flexible tube filled with a fluid having elasticity, surface friction coefficient, and strength suitable for preventing the narrow-width coil from falling over as a holder for pressing and holding the narrow-width coil.

Prior Art Documents

Patent Documents

[0010] Patent Document 1 Japanese Patent Laid-Open No. 4-33719 Patent Document 2 Japanese Patent Laid-Open No. 4-75718 SUMMARY OF THE INVENTION PROBLEMS TO BE SOLVED BY THE INVENTION

[0011] However, the above prior art has the following problems. The technique disclosed in Patent Document 1 is intended to prevent the coil from tipping over when carried out by a coil carriage for a single metal strip coil. Further, the technique disclosed in Patent Document 2 is intended to prevent tipping over when transferring a narrow-width coil cut into a plurality of strips by a coil carriage. For this reason, these techniques cannot be applied to suppressing tipping over when carrying out some of the plurality of metal strip coils placed adjacent to each other with their sides facing each other, such as metal strip coils cut by a slitter line.

[0012] The present invention has been made to solve the above problems, and an object thereof is to provide a coil tipping risk degree calculation method and a coil tipping risk degree calculation device capable of calculating the tipping risk degree of a determination target coil placed on a fixed skid adjacent to a coil to be carried out with its side facing the side of the coil to be carried out. Another object of the present invention is to provide a coil tipping suppression method capable of suppressing tipping over of the determination target coil. MEANS FOR SOLVING THE PROBLEMS

[0013] The means for solving the above problems are as follows. [1] A method for calculating the risk of tipping of a coil, when carrying out the coil to be carried out from a fixed skid on which the coil to be carried out and the coil to be judged are placed with their side surfaces facing each other, using a coil cart having a movable skid, the method comprising: a measuring step of measuring the distance between the side surface of the coil to be carried out and the side surface of the coil to be judged while the coil to be carried out is being lifted by the movable skid; and a calculating step of calculating the risk of tipping of the coil to be judged using the distance. [2] In the calculating step, the center of gravity position of the coil to be judged in the horizontal direction is calculated using the distance, and the risk of tipping is calculated based on the center of gravity position with respect to the fulcrum position of the coil to be judged in the horizontal direction. The method for calculating the risk of tipping of a coil according to [1]. [3] A method for suppressing tipping of a coil, comprising: calculating the risk of tipping using the method for calculating the risk of tipping of a coil according to [1] or [2]; and a step of stopping the ascent of the movable skid when the risk of tipping is equal to or greater than a predetermined threshold value. [4] The method for suppressing tipping of a coil according to [3], further comprising a step of changing the horizontal position of the movable skid when the risk of tipping is equal to or greater than a predetermined threshold value. [5] A device for calculating the risk of tipping of a coil, when carrying out the coil to be carried out from a fixed skid on which the coil to be carried out and the coil to be judged are placed with their side surfaces facing each other, using a coil cart having a movable skid, the device comprising: a measuring unit for measuring the distance between the side surface of the coil to be carried out and the side surface of the coil to be judged; and a calculating unit for calculating the risk of tipping of the coil to be judged using the distance. [Effect of the Invention]

[0014] By using the method for calculating the tipping risk of a coil and the device for calculating the tipping risk of a coil according to the present invention, when carrying out the coil to be carried out, the tipping risk of the coil to be judged placed on the fixed skid adjacent to the coil to be carried out can be calculated. Further, by using the method for suppressing the tipping of a coil according to the present invention, when carrying out the coil to be carried out, the tipping of the coil to be judged placed on the fixed skid adjacent to the coil to be carried out can be suppressed.

Brief Description of Drawings

[0015]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Best Mode for Carrying Out the Invention

[0016] Hereinafter, the present invention will be specifically described through embodiments of the present invention. The following embodiments show a preferred example of the present invention, and the present invention is not limited by these embodiments in any way.

[0017] The coil for which the tipping risk degree is calculated by the coil tipping risk degree calculation method and the coil tipping risk degree calculation device according to the embodiment is, for example, a coil in which a strip-shaped metal strip or the like is wound in a roll shape. The metal strip is, for example, a metal such as steel, copper, or aluminum formed into a strip shape. However, the coil for which the tipping risk degree is calculated by the coil tipping risk degree calculation method and the coil tipping risk degree calculation device according to the present embodiment is not limited to a coil in which a strip-shaped metal strip is wound in a roll shape, and may be a coil in which a sheet-like material such as a non-woven fabric, paper, or film is wound in a roll shape. Hereinafter, an example in which the present embodiment is applied to a coil in which a strip-shaped metal strip is wound in a roll shape will be used for explanation.

[0018] FIG. 1 is a schematic diagram showing a determination target coil and a carry-out target coil for which the tipping risk degree is calculated by the coil tipping risk degree calculation method and the coil tipping risk degree calculation device according to the present embodiment. FIG. 1(a) is a schematic diagram showing two coils 20a and 20b wound by a tension reel 12. FIG. 1(b) is a schematic diagram showing two coils 20a and 20b placed on a fixed skid 16.

[0019] Coils 20a and 20b are formed by being cut (slit) into two along the conveying direction of the metal strip in the slitter line and then being wound around the tension reel 12 of the winder 10. As shown in Fig. 1(a), on the tension reel 12, the metal strip is wound with a plurality of coils 20a and 20b adjacent to each other with their side faces facing each other. The coils 20a and 20b formed on the tension reel 12 are placed on the fixed skid 16 by the transfer device 14. The transfer device 14 is, for example, a transport cart, and the coils 20a and 20b are placed on the fixed skid 16 while remaining adjacent to each other by the transport cart. Fig. 1(b) shows this state.

[0020] The method for calculating the risk of coil tipping and the device for calculating the risk of coil tipping according to the embodiment target the process of unloading coil 20b in a state where a plurality of coils 20a and 20b are placed on the fixed skid 16 with their side faces facing each other, and calculate the risk of tipping of coil 20a in this process. In the example shown in Fig. 1(b), coil 20b is the coil to be unloaded by the movable skid, and coil 20a adjacent to the coil to be unloaded is the coil to be judged for which the risk of tipping is calculated.

[0021] The state where coil 20a and coil 20b are placed adjacent to each other with their side faces facing each other on the fixed skid 16 includes not only the state where the side face of coil 20a and the side face of coil 20b are in contact and placed, but also the state where coil 20a and coil 20b are placed with a distance of 5 mm or less between their side faces. This is because when the distance between the side face of coil 20a and the side face of coil 20b is 5 mm or less, coil 20a, which is the coil to be judged, may be tipped over when being unloaded by the movable skid.

[0022] Fig. 2 is a schematic diagram showing the coil cart equipment 30. Fig. 2(a) is a perspective view of the coil cart equipment 30, and Fig. 2(b) is a front view of the coil cart 32 with coil 20b lifted. The coil cart equipment 30 will be described with reference to Fig. 2.

[0023] The coil bogie equipment 30 includes a coil bogie 32 and a bogie control device 44 that controls the operation of the coil bogie 32. The coil bogie 32 is a bogie for carrying out the coil on the fixed skid 16, and includes a bogie body 34, a lifting device 36, and a movable skid 38. The bogie body 34 is the main body part of the bogie for carrying out the coil 20b which is the object to be carried out. The bogie body 34 has wheels 40 that run on the track 42 laid in the factory and an electric motor (not shown) that drives the wheels 40.

[0024] The lifting device 36 is connected to the bogie body 34 and raises and lowers the movable skid 38 up and down. The lifting device 36 is, for example, a pressure cylinder or an electric motor. The movable skid 38 is, for example, a V-shaped skid with a V-shaped cross section. By using the V-shaped skid, the coil 20b to be carried out can be stably raised and lowered. The movable skid 38 pushes up the coil 20b from below during ascent and supports the coil 20b during descent. Further, the movable skid 38 supports the coil 20b against the inertial force of the coil 20b acting when the coil bogie 32 travels due to the frictional force between the movable skid 38 and the coil 20b.

[0025] A sensor (not shown) for detecting the position of the coil bogie 32 on the track 42 is provided on the bogie body 34. The bogie control device 44 is a device that controls the travel of the coil bogie 32. The bogie control device 44 is a dedicated computer for executing sequence control, such as a PLC (Programmable Logic Controller), for example. The bogie control device 44 acquires a signal output from a sensor provided on the coil bogie 32 to specify the position of the bogie body 34 on the track 42, and controls the travel of the coil bogie 32 and the raising and lowering operations of the lifting device 36 based on the position.

[0026] FIG. 3 is a schematic diagram for explaining the process of unloading one of the two coils 20a and 20b when the two coils 20a and 20b are placed adjacent to each other on the fixed skid 16. FIG. 3(a) is a schematic diagram for explaining the approaching step of bringing the coil carriage 32 close to the coil 20b which is the coil to be unloaded. In the approaching step, the carriage control device 44 identifies the coil 20b to be unloaded as the coil to be unloaded, and moves the coil carriage 32 to the position where the coil 20b is placed. The carriage control device 44 stops the coil carriage 32 when the position of the movable skid 38 reaches a position where the coil 20b can be lifted. Note that the operator may manually control the stop position of the coil carriage 32.

[0027] FIG. 3(b) is a schematic diagram for explaining the lifting step of lifting the coil 20b by the movable skid 38. In the lifting step, the carriage control device 44 raises the lifting device 36 to raise the movable skid 38. Thereby, the coil 20b is lifted by the movable skid 38 and isolated from the fixed skid 16. The lifting height of the movable skid 38 is set in advance in the carriage control device 44. For example, the coil 20b is lifted to a height about 100 to 200 mm away from the fixed skid 16.

[0028] FIG. 3(c) is a schematic diagram for explaining the retracting step of retracting the coil carriage 32 from the fixed skid 16. In the retracting step, the carriage control device 44 retracts the coil carriage 32 from the position where the fixed skid 16 is installed while keeping the movable skid 38 raised to isolate the coil 20b from the fixed skid 16.

[0029] FIG. 3(d) is a schematic diagram for explaining the lowering step of lowering the movable skid 38 to lower the coil 20b. In the lowering step, the carriage control device 44 lowers the movable skid 38 at a position where the coil 20b does not contact the fixed skid 16. Thereby, since the support position of the coil 20b becomes lower, the coil 20b can be stably supported and carried out. Further, the coil 20b may be fixed to the movable skid 38 by a fixture or the like in a state where the coil 20b is lowered. By fixing the coil 20b with a fixture, it is possible to prevent the coil 20b from tipping over or falling when the coil carriage 32 travels.

[0030] The coil 20b supported by the coil carriage 32 is carried to a predetermined unloading destination under the control of the carriage control device 44 and unloaded. In this way, the coil 20b is carried by the coil carriage 32. By carrying out the coil 20b, the coil 20a is placed alone on the fixed skid 16. If the coil 20a can be placed alone in this way, it becomes easier to lift the coil 20a on the fixed skid 16 by a crane, and the coil 20a can be carried to a predetermined position by the crane, and the unloading of the coil can be made more efficient.

[0031] Further, instead of performing the lowering step shown in FIG. 3(d) on the coil 20b, the coil 20b may be returned to the fixed skid 16 that has become empty after the coil 20a has been carried out by a crane. Thereby, since the coil 20b can also be carried to the unloading destination using a crane, the unloading of the coil to the predetermined unloading destination can be made more efficient.

[0032] In the process of carrying out such a coil 20b, in the ascending step of raising the movable skid 38, there is a risk that the coil 20a, which is the coil to be judged and is placed adjacent to the coil 20b that is the coil to be carried out, will fall. For example, in the ascending step, when the coil 20b sways, it may contact the coil 20a and the coil 20a may fall. Also, even if the boundary between the coil 20b and the coil 20a is separated, if the winding shapes of the coil 20b and the coil 20a are non-uniform, when the coil 20b sways in the ascending step, it may contact the coil 20a and the coil 20a may fall.

[0033] In the method for calculating the risk of coil toppling and the device for calculating the risk of coil toppling according to the present embodiment, during the process of raising the coil 20b, the risk of toppling of the coil 20a, which is the coil to be judged, is calculated. FIG. 4 is a schematic diagram showing a configuration example of a device 50 for calculating the risk of coil toppling in which the method for calculating the risk of coil toppling according to the present embodiment can be implemented.

[0034] The device 50 for calculating the risk of coil toppling has a distance meter 52 and an arithmetic unit 54. The distance meter 52 is arranged on the front surfaces of the coils 20a and 20b. The distance meter 52 is, for example, a laser distance meter. The distance meter 52 scans the coils 20a and 20b with laser light in a fan shape at a sampling rate of, for example, 20 Hz. The sampling rate of the distance meter 52 is preferably within the range of 10 to 60 Hz.

[0035] In the distance meter 52, the detection signal obtained by scanning with laser light is amplified by an amplifier, and the signal is converted into distance information between the side surface of the coil 20a and the side surface of the coil 20b and output to the arithmetic unit 54. In the following description, the distance between the side surface of the coil 20a and the side surface of the coil 20b will be referred to as the "gap between coils". The distance meter 52 is an example of a measuring unit that measures the gap between coils of the coils 20a and 20b.

[0036] FIG. 5 is a diagram for explaining the coil gap between coils 20a and 20b measured by the distance meter 52. On the fixed skid 16, the coils 20a and 20b are placed adjacent to each other in a direction such that the traveling direction of the coil carriage 32 and the axial direction of the coils are substantially parallel. When the axial direction of the coils 20a and 20b is the x direction, the direction in which the movable skid 38 rises in the ascending step is the y direction, and the depth direction is the z direction, the distance meter 52 scans the laser beam in the x direction to measure the coil gap between the coils 20a and 20b.

[0037] As shown in FIG. 5, the distance meter 52 scans the laser beam at a position above the axis C of the coil 20b before starting the ascending step and below the upper surface of the coil 20b. In this case, the position H in the height direction where the laser beam is scanned is preferably in the range of 0.5×D1≦H<D1 when the outer diameter of the coil 20b, which is the coil to be carried out, is D1. When the height H at which the laser beam is scanned is less than 0.5×D1, it may not be possible to measure the coil gap in the ascending step, which is not preferable. Also, when the height H at which the laser beam is scanned coincides with D1, disturbance may occur in the measured value of the distance meter 52, which is not preferable.

[0038] FIG. 6 is a diagram showing an example of a detection signal measured by the distance meter 52. The distance meter 52 scans the laser beam to acquire a detection signal indicating the distances between the distance meter 52 and the coils 20a and 20b. As shown in FIG. 6, since the distance of the coil gap portion is measured largely in the detection signal, the distance meter 52 can measure the distance between both ends as the coil gap δ by specifying the range of the coil gap.

[0039] Note that the measuring unit may be other devices instead of just a laser distance meter as long as it can measure the coil gap between the coils 20a and 20b. For example, a device that measures the coil gap between the coils 20a and 20b may be used, which captures images of the coils 20a and 20b to generate image data, extracts the side surfaces of the coils 20a and 20b in the generated image data, and determines the distance between the extracted side surfaces.

[0040] The distance meter 52 outputs distance information indicating the measured coil gap δ to the arithmetic unit 54. The arithmetic unit 54 calculates the tipping risk degree of the coil 20a, which is the coil to be determined, using the distance information indicating the coil gap δ measured by the distance meter 52. Further, when the tipping risk degree of the coil 20a is equal to or higher than a predetermined threshold value, the arithmetic unit 54 outputs a signal to the carriage control device 44 to stop the ascent of the movable skid 38 by the lifting device 36, thereby stopping the ascent of the movable skid 38. Furthermore, when the tipping risk degree of the coil 20a is equal to or higher than a predetermined threshold value, the arithmetic unit 54 lowers the lifting device 36 and outputs a signal to the carriage control device 44 to change the horizontal position of the carriage body 34, thereby changing the position of the movable skid 38 in the horizontal direction.

[0041] Next, the arithmetic unit 54 will be described. FIG. 7 is a schematic diagram showing a configuration example of the arithmetic unit 54 and the configuration related to the arithmetic unit. The arithmetic unit 54 is a general-purpose computer such as a workstation or a personal computer, for example. The arithmetic unit 54 includes a control unit 56, an input unit 58, an output unit 60, and a storage unit 62.

[0042] The control unit 56 is, for example, a CPU or the like, and by executing various programs stored in the storage unit 62, the control unit 56 functions as an acquisition unit 64 and a calculation unit 66. The input unit 58 is, for example, a keyboard, a touch panel provided integrally with a display, or the like. The output unit 60 is, for example, an LCD or a CRT display or the like. The storage unit 62 is, for example, a rewritable flash memory, a hard disk built-in or connected by a data communication terminal, an information recording medium such as a memory card, and a reading and writing device thereof. In the storage unit 62, programs and arithmetic expressions used to calculate the tipping risk of the coil 20a using the distance information between the side surface of the coil 20a and the side surface of the coil 20b acquired from the distance meter 52 are stored.

[0043] Next, the processes executed by the acquisition unit 64 and the calculation unit 66 will be described. When the acquisition unit 64 acquires distance information from the distance meter 52, the acquisition unit 64 outputs the distance information to the calculation unit 66. Note that the acquisition unit 64 may store the distance information acquired from the distance meter 52 in the storage unit 62 as time-series data associated with the acquired time.

[0044] When the calculation unit 66 acquires distance information, the calculation unit 66 calculates the tipping risk of the coil 20a using the distance information. When the acquisition unit 64 stores the distance information in the storage unit 62, the calculation unit 66 reads the distance information from the storage unit 62.

[0045] FIG. 8 is a schematic diagram showing a state in which the coil 20a tilts about the fulcrum P. The coil 20a, which is the coil to be determined, tilts with the end on the side opposite to the coil 20b as the fulcrum P and may tip over. On the other hand, even if the coil 20a tilts with the end on the side close to the coil 20b as the fulcrum, since the coil 20b exists, the coil 20a does not tip over to the coil 20b side. Therefore, the tipping risk of the coil 20a may be considered in terms of tilting about the fulcrum P, which is the end on the side opposite to the coil 20b.

[0046] Figure 8 shows a state in which the coil 20a, which is the coil to be determined, tilts about the fulcrum P and tilts to the tilt angle θ. At this time, if the position of the center of gravity G of the coil 20a in the horizontal direction (x direction) is located on the right side of the fulcrum P, a restoring force that restores to the original position acts on the coil 20a due to the gravity acting on it. On the other hand, if the position of the center of gravity G in the horizontal direction is located on the left side of the fulcrum P, the coil 20a will fall due to gravity. Therefore, in the coil overturning risk degree calculation device according to the present embodiment, based on the position where the position of the center of gravity G of the coil 20a in the horizontal direction (x direction) coincides with the fulcrum P, the overturning risk degree is calculated based on the position of the center of gravity G of the coil 20a with respect to the position of the fulcrum P in the horizontal direction. First, a method for calculating the coil gap δ in which the position of the center of gravity G of the coil 20a in the horizontal direction coincides with the fulcrum P will be described.

[0047] As shown in FIG. 8, the coil gap δ is calculated by the sum of the initial gap δ0 and the gaps δ1 and δ2 divided from the geometric relationship according to the tilting state of the coil 20a. Since the coil gap δ1 is the displacement in the x direction of the lower end due to the tilt of the coil 20a, it can be calculated by the following formula (1). In the following formulas (1) to (9), δ, δ0, δ1, and δ2 are the coil gaps (m) shown in FIG. 8, H is the measured height (m) by the distance meter 52, W is the width (m) of the coil 20a which is the coil to be determined, D2 is the outer diameter (m) of the coil 20a, and θ is the tilt angle (°) of the coil 20a.

[0048] δ1 = W - W×cosθ ···(1)

[0049] The coil gap δ2 can be calculated by the following formula (2) from the geometric relationship shown in FIG. 8.

[0050] δ2 = (H - W×sinθ)×tanθ ···(2)

[0051] The coil gap δ can be calculated by the following formula (3) using the initial gap δ0 and the coil gaps δ1 and δ2.

[0052] δ = δ0 + δ1 + δ2 =δ0 + W - W×cosθ + (H - W×sinθ)×tanθ ···(3)

[0053] On the other hand, the condition that the position of the center of gravity G of the coil 20a in the horizontal direction (x direction) coincides with the fulcrum P is expressed by the following equation (4).

[0054] θ = tan -1 (W / D2) ···(4)

[0055] Therefore, in this case, the following equations (5) to (7) hold.

[0056]

Equation

[0057]

Equation

[0058]

Equation

[0059] [[ID=

Equation

[0060]

Equation

[0061] In the apparatus for calculating the tipping risk of the coil according to the present embodiment, the tipping risk is calculated based on the position of the center of gravity of the coil 20a with respect to the fulcrum position of the coil 20a in the horizontal direction. That is, the coil gap δ when the coil 20a is not tilted at all is set as the tipping risk 0, and the above limit coil gap δ LimThe tipping risk is calculated as a value from 0 to 100 with the tipping risk of 100.

[0062] Again, referring to FIG. 7. When the calculation unit 66 obtains the inter-coil gap δ, it calculates the tipping risk using the inter-coil gap δ and the following formula (9). Note that δ Lim The following formula (9) including δ and δ0 is calculated in advance and stored in the storage unit 62 through the input unit 58. When the tipping risk calculated by the calculation unit 66 is a negative value, the tipping risk is set to 0. Also, when the tipping risk calculated by the calculation unit 66 is a value exceeding 100, the tipping risk is set to 100. Note that when the tipping risk calculated by the following formula (9) is a value exceeding 100, the calculation unit 66 may use the value exceeding 100 as the tipping risk as it is.

[0063] Tipping risk = (δ - δ0) × 100 / (δ Lim - δ0) ··· (9)

[0064] When the calculation unit 66 calculates the tipping risk, it may display the calculated tipping risk on the output unit 60. FIG. 9 is a diagram showing another display example of the tipping risk. As shown in FIG. 9, the calculation unit 66 may display the tipping risk as information quantized into three values of "Safe", "Caution", or "Danger". In this case, when the tipping risk calculated using the above formula (9) is 50 or more, the calculation unit 66 specifies that the tipping risk is "Danger" and causes the output unit 60 to display a display indicating "Danger". Also, when the tipping risk is 25 or more and less than 50, the calculation unit 66 causes the output unit 60 to display a display indicating "Caution", and when the tipping risk is less than 25, the calculation unit 66 causes the output unit 60 to display a display indicating "Safe". Thereby, the tipping risk can be clearly displayed, and even an operator who does not know the meaning of the numerical value of the tipping risk can visually recognize the tipping risk of the coil 20a. Note that the tipping risk may be displayed as information quantized into two values of "Danger" when the tipping risk is 50 or more and "Safe" when the tipping risk is less than 50.

[0065] Further, when the calculated risk of tipping is equal to or higher than a predetermined threshold value, the calculation unit 66 outputs a signal to the carriage control device 44 to stop the ascent of the movable skid 38, and stops the ascent of the movable skid 38 by the lifting device 36. Thereby, the tipping of the coil 20a can be suppressed. The threshold value of the risk of tipping is, for example, "50", and the threshold value is stored in the storage unit 62 in advance through the input unit 58. The threshold value of the risk of tipping is preferably determined, for example, within a range greater than 0 and equal to or less than 70, and more preferably within a range of 30 or more and 70 or less.

[0066] Furthermore, when the calculated risk of tipping is equal to or higher than the threshold value, the calculation unit 66 lowers the position of the movable skid 38 to the carriage control device 44, and outputs a signal to change the position of the horizontal direction of the coil carriage 32 by a predetermined distance in a direction away from the coil 20a. As a result, the coil carriage 32 moves, and the horizontal position of the movable skid 38 is changed in a direction away from the coil 20a. As a result, the movable skid 38 can lift the coil 20b without colliding with the coil 20a, and the coil 20b can be carried out.

[0067] In this way, by using the coil tipping risk calculation device 50 according to the present embodiment, when carrying out the coil 20b which is the coil to be carried out, the tipping risk of the coil 20a which is the coil to be determined can be calculated. By calculating the risk of tipping in this way, various measures can be taken to suppress the tipping of the coil 20a using the risk of tipping. Specifically, based on the calculated risk of tipping, the ascent of the movable skid 38 can be stopped, or the horizontal position of the movable skid 38 can be changed, thereby suppressing the tipping of the coil 20a which is the coil to be determined, and enabling the coil 20b which is the coil to be carried out to be carried out.

[0068] Next, a method for calculating the tipping risk of a coil and a method for suppressing the tipping of a coil according to this embodiment will be described. FIG. 10 is a flowchart showing the flow of the method for calculating the tipping risk of a coil and the method for suppressing the tipping of a coil according to this embodiment. The flow shown in FIG. 10 starts on the condition that, for example, an instruction to carry out the coil 20b, which is the coil to be carried out, is input to the carriage control device 44.

[0069] The distance meter 52 measures the gap δ between coils at a sampling rate of 20 Hz (step S101), and outputs the distance information obtained by the measurement to the arithmetic unit 54. The process of this step S101 is the measurement step in the method for calculating the tipping risk of a coil and the method for suppressing the tipping of a coil according to this embodiment.

[0070] The calculation unit 66 of the arithmetic unit 54 calculates the tipping risk using the acquired distance information and the above formula (9) (step S102). The process of this step S102 is the calculation step in the method for calculating the tipping risk of a coil and the method for suppressing the tipping of a coil according to this embodiment.

[0071] The calculation unit 66 determines whether or not the calculated tipping risk is equal to or greater than the threshold value (step S103). The calculation unit 66 compares the calculated tipping risk with the threshold value read from the storage unit 62, and determines whether or not the tipping risk is equal to or greater than the threshold value.

[0072] When the calculation unit 66 determines that the tipping risk is equal to or greater than the threshold value as a result of comparing the calculated tipping risk with the threshold value (step S103: Yes), the calculation unit 66 outputs a signal to the carriage control device 44 to stop the raising of the movable skid 38, and stops the raising of the movable skid 38 by the lifting device 36 (step S104). The process of this step S104 is the movable skid stop step in the method for suppressing the tipping of a coil.

[0073] The calculation unit 66 further outputs a signal for changing the position of the coil carriage 32 in the horizontal direction by a predetermined distance (10 to 100 mm) in a direction away from the coil 20a, and moves the coil carriage 32 to change the position of the coil carriage 32 in the horizontal direction (step S105). The process of step S105 is the movable skid position changing step in the coil overturning prevention method. After that, the calculation unit 66 returns the process to step S101 and repeatedly executes the processes of steps S101 to S103. The coil carriage 32 raises the lifting device 36 and raises the movable skid 38 again under the control of the carriage control device 44.

[0074] On the other hand, when the calculation unit 66 determines that the overturning risk level is less than the threshold value as a result of comparing the calculated overturning risk level with the threshold value (step S103: No), the calculation unit 66 continues to raise the movable skid 38 and advances the process to step S106. The calculation unit 66 determines whether or not the unloading of the coil 20b, which is the coil to be unloaded, is completed. To make this determination, the calculation unit 66 may acquire information indicating the lifting position of the movable skid 38 from the carriage control device 44, or may acquire information indicating the position of the coil carriage 32 in the horizontal direction from the carriage control device 44.

[0075] For example, when the calculation unit 66 acquires information indicating the horizontal position of the coil carriage 32 from the carriage control device 44, it may determine whether the unloading of the coil 20b is completed based on whether the horizontal position of the coil carriage 32 has reached a predetermined position away from the fixed skid 16. When the coil carriage 32 has reached the predetermined position, the calculation unit 66 determines that the unloading of the coil to be unloaded is completed (step S106: Yes) and ends the flow shown in FIG. 10. On the other hand, when the horizontal position of the coil carriage 32 has not reached the predetermined position, the calculation unit 66 determines that the unloading of the coil 20b, which is the coil to be unloaded, is not completed (step S106: No), returns the process to step S101, and repeats the process from step S101 again. As a result, from the start to the completion of the unloading of the coil 20b, which is the coil to be unloaded, the coil gap δ is measured, the tipping risk of the coil 20a, which is the coil to be determined, is calculated, and the tipping of the coil 20a can be suppressed. Further, by calculating the tipping risk in this way, it becomes possible to grasp the temporal change in the tipping risk of the coil 20a, which is the coil to be determined.

[0076] As described above, by using the method for calculating the tipping risk of the coil according to the present embodiment, when unloading the coil 20b, which is the coil to be unloaded, it is possible to calculate the tipping risk of the coil 20a, which is the coil to be determined and is placed on the fixed skid adjacent to the coil 20b. Further, by using the method for suppressing the tipping of the coil according to the present embodiment, it becomes possible to unload the coil 20b, which is the coil to be unloaded, while suppressing the tipping of the coil 20a, which is the coil to be determined.

[0077] In the above embodiment, the coil 20a as the coil to be determined and the coil 20b as the coil to be carried out are placed on the fixed skid 16, and an example of calculating the risk of tipping of the coil 20a when carrying out the coil 20b is shown, but the present invention is not limited thereto. FIG. 11 is a schematic diagram showing another example of the coil to be determined and the coil to be carried out. FIG. 11(a) is a schematic diagram showing an example in which there is one coil to be determined and one coil to be carried out. On the other hand, FIG. 11(b) is a schematic diagram showing an example in which there is one coil to be determined and two coils to be carried out. Further, FIG. 11(c) is a schematic diagram showing an example in which there are two coils to be determined and two coils to be carried out.

[0078] As shown in FIG. 11(b), in the tipping risk calculation device and the tipping risk calculation method according to the present embodiment, three coils are placed on the fixed skid 16, and the tipping risk of the coil 20a when carrying out two of the coils 20b and 20c can be calculated in the same manner. In this case, the distance meter 52 measures the inter-coil gap δ between the coil 20a and the coil 20b, and the calculation unit 66 calculates the tipping risk of the coil 20a using the inter-coil gap δ.

[0079] Furthermore, as shown in FIG. 11(c), in the tipping risk calculation device and the tipping risk calculation method according to the present embodiment, four coils are placed on the fixed skid 16, and the tipping risk of the coil 20a when carrying out two of the coils 20b and 20c can be calculated in the same manner. In this case, the distance meter 52 measures the inter-coil gap δ between the coil 20a and the coil 20b, and the calculation unit 66 calculates the tipping risk of the coil 20a using the inter-coil gap δ.

[0080] However, since the tilting of coil 20a is restricted by coil 20d placed adjacent to coil 20a, the coil-to-coil gap δ between coil 20a and coil 20b becomes smaller. Therefore, in the case shown in Fig. 11(c), the coil-to-coil gap δ between coil 20a and coil 20b becomes smaller, and the risk of coil 20a tipping over becomes smaller. Thus, the tipping risk calculation device and the tipping risk calculation method according to this embodiment are not limited to the case where two coils are placed on the fixed skid 16, but can also calculate the tipping risk of the coil when three or more coils are placed and one or more of them are carried out by the coil carriage 32.

[0081] In addition, in the coil tipping risk calculation device and the coil tipping risk calculation method according to this embodiment, an example is shown in which the coil-to-coil gap δ between coil 20a and coil 20b is measured and the tipping risk is calculated using the coil-to-coil gap δ, but it is not limited to this. For example, when the main cause of coil 20a tipping over is the accidental rise of coil 20a by the movable skid 38, the coil-to-coil gap δ between coil 20a and coil 20b when the movable skid 38 is raised is measured, and from that value, the coil-to-coil gap δ when the movable skid 38 reaches the upper limit of the raised position is estimated, and the tipping risk of the coil may be calculated using the coil gap δ.

[0082] In this case, the calculation unit 66 first identifies the horizontal position of the movable skid 38 using the amount of rise of the movable skid 38 before reaching the upper limit of the raised position and the measured coil-to-coil gap δ. Then, at the identified horizontal position, the coil-to-coil gap δ when the movable skid 38 reaches the upper limit of the raised position is estimated, and the tipping risk of the coil is calculated using the estimated coil-to-coil gap δ. As a result, the tipping risk of the coil to be determined can be judged earlier.

[0083] Also, in the above embodiment, an example is shown in which the tipping risk is calculated by the above formula (9), but it is not limited to this. For example, the tipping risk may be indicated by the coil-to-coil gap δ, and the limit coil-to-coil gap δ LimIt may also be indicated by the difference from the measured gap δ between the coils. On the other hand, when the risk of tipping is indicated by the gap δ between the coils, the possibility of the coil 20a tipping varies depending on the outer dimensions and plate width dimensions of the coil 20a, which is the coil to be determined. Therefore, when the risk of tipping is indicated by the gap δ between the coils, it is preferable to determine in advance the threshold value of the risk of tipping for each outer dimension and plate width dimension of the coil to be determined.

Explanation of Signs

[0084] 10 Take-up machine 12 Tension reel 14 Transfer device 16 Fixed skid 20a Coil 20b Coil 20c Coil 20d Coil 30 Coil carriage equipment 32 Coil carriage 34 Carriage body 36 Lifting device 38 Movable skid 40 Wheels 42 Tracks 44 Carriage control device 50 Coil tipping risk calculation device 52 Distance meter 54 Arithmetic unit 56 Control unit 58 Input unit 60 Output unit 62 Storage unit 64 Acquisition unit 66 Calculation unit

Claims

1. A method for calculating the risk of tipping over of a coil, when unloading the coil to be unloaded using a coil carriage having a movable skid from a fixed skid on which the coil to be unloaded and the coil to be judged are placed with their side surfaces facing each other, comprising: a measuring step of measuring the distance between the side surface of the coil to be unloaded and the side surface of the coil to be judged while the movable skid is lifting the coil to be unloaded; a calculating step of calculating the risk of tipping over of the coil to be judged using the distance; A method for calculating the risk of tipping over of a coil, including the above steps.

2. In the calculating step, the center of gravity position of the coil to be judged in the horizontal direction is calculated using the distance, The method for calculating the risk of tipping over of a coil according to claim 1, wherein the risk of tipping over is calculated based on the center of gravity position with respect to the fulcrum position of the coil to be judged in the horizontal direction.

3. Calculating the risk of tipping over using the method for calculating the risk of tipping over of a coil according to claim 1 or claim 2, A method for suppressing tipping over of a coil, including a step of stopping the ascent of the movable skid when the risk of tipping over is equal to or greater than a predetermined threshold value.

4. The method for suppressing tipping over of a coil according to claim 3, including a step of changing the horizontal position of the movable skid when the risk of tipping over is equal to or greater than a predetermined threshold value.

5. A device for calculating the risk of tipping over of a coil, when unloading the coil to be unloaded using a coil carriage having a movable skid from a fixed skid on which the coil to be unloaded and the coil to be judged are placed with their side surfaces facing each other, comprising: a measuring unit for measuring the distance between the side surface of the coil to be unloaded and the side surface of the coil to be judged; a calculating unit for calculating the risk of tipping over of the coil to be judged using the distance; A device for calculating the risk of tipping over of a coil, having the above components.

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