JP7740322B2 - Coil inner diameter sagging correction member and method of manufacturing metal strip - Google Patents

Description

The present invention relates to a coil inner diameter sagging correction device that is attached to a payoff reel to correct inner diameter sagging that occurs on the inner diameter side of a metal strip coil, and a method for manufacturing metal strips.

When loading a metal strip coil onto the mandrel of a payoff reel, which pays off coiled metal strip, inner diameter sagging, where the end of the metal strip coil sags, can occur on the inner diameter side of the metal strip coil. When this inner diameter sagging occurs, it becomes an obstacle, making it difficult to load the metal strip coil from the reel of the payoff reel onto the mandrel. There is also the risk that the inner diameter sagging may interfere with the mandrel and damage the metal strip coil, or that the metal strip coil may not fit on the mandrel and fall.

This inner diameter sagging is particularly likely to occur in thin metal strips with low rigidity. Conventionally, for metal strip coils with inner diameter sagging, after alignment, the metal strip coil is temporarily brought close to the payoff reel, and several turns of the inner diameter portion are manually pushed toward the payoff reel to bridge the gap. Then, the metal strip coil is loaded onto the mandrel of the payoff reel, and special work is required, such as cutting off the inner diameter sagging portion before loading the metal strip onto the mandrel of the payoff reel, resulting in lost time during coil replacement and lost yield.
Various methods have been proposed for preventing the sagging of the inner diameter of the metal strip coil.

For example, in the case of the tape for the beginning and end of a metal strip coil shown in Patent Document 1, the beginning and end of the coil are wound tightly and attached with tape to prevent sagging.
In addition, in the tail end securing device for a steel strip coil shown in Patent Document 2, a steel strip is inserted between plates near the innermost winding of the steel strip coil, the steel strip is sheared, and then the steel strip is bent toward the inner diameter of the steel strip coil and clipped.

Furthermore, in a device for preventing loosening of the coil winding start end shown in Patent Document 3, the winding start end of the inner diameter part of the cold-rolled coil is pressed against the inner diameter surface with a pressure roll to make it adhere tightly, and then a U-shaped clip is inserted into this part to clamp and hold it in place.
Furthermore, in the automatic welding device for the inner diameter of a metal strip coil shown in Patent Document 4, the inner hanging tip of the metal strip coil is pressed from the inside of the coil, and a metal ribbon is applied to the inner tip of the coil and temporarily fastened with a welding machine.

In addition, in the method of welding the start end of a steel sheet coil disclosed in Patent Document 5, the seams at both ends in the sheet width direction of the start end of the steel sheet are welded on the reel.
Furthermore, Patent Document 6 discloses a method for preventing loosening of the winding start end of a metal strip coil, in which the winding start end of the coil is detected, adhesive is applied to the back surface of the winding start end or to the inner diameter surface of the coil that overlaps the winding start end, and then the winding start end of the coil is pressed against the inner diameter side of the coil to fix it.

Furthermore, in the method of temporarily fastening a metal strip coil shown in Patent Document 7, when the metal strip is wound on a winding reel, adhesive is applied to one of the upper surface of the metal strip corresponding to the innermost diameter part of the coil to be wound and the lower surface of the metal strip that is wound in contact with the innermost diameter part of the coil, and then the metal strip is wound.
In addition, in the method of attaching a coil to a payoff reel shown in Patent Document 8, an inner diameter sagging detection sensor detects the inner diameter sagging amount of the carp, and calculates the reel diameter of the payoff reel that can be loaded into the coil based on the detected inner diameter sagging amount.The payoff reel is then expanded or contracted to achieve the calculated reel diameter and loaded into the coil.

In addition, in the coil insertion method shown in Patent Document 9, a coil inner diameter holding jig is attached inside the steel strip coil, and the steel strip coil is inserted into the payoff reel, so that the inner diameter sagging that occurs in the inner diameter part of the coil is corrected while insertion is being performed.
Furthermore, in the coil insertion method shown in Patent Document 10, a reel drum cap is attached to the tip of the reel drum via a rubber sleeve, and the steel strip coil is inserted into the payoff reel, so that the inner diameter sagging that occurs in the inner diameter part of the coil is corrected during insertion.

Japanese Unexamined Patent Publication No. 1-278913 Japanese Unexamined Patent Publication No. 1-170519 Japanese Patent Application Publication No. 1-266918 Special Publication No. 3-49670 Japanese Unexamined Patent Publication No. 1-309722 Japanese Patent Application Publication No. 5-38520 Japanese Unexamined Patent Publication No. 2-224816 Japanese Patent Application Laid-Open No. 2000-254726 Japanese Patent Application Laid-Open No. 2006-167723 Japanese Patent Application Laid-Open No. 2008-246544

However, the conventional tape at the beginning and end of the metal strip coil shown in Patent Document 1 had the problem that pieces of tape would adhere to the threading rolls, etc., leading to quality defects in the metal strip coil such as scratches and foreign matter adhesion.

Furthermore, with the steel strip coil tail end securing device shown in Patent Document 2 and the coil winding start end slack securing device shown in Patent Document 3, the clips would fall into the coil car pit and be difficult to retrieve, leading to problems with the coil car equipment that transports the coils. Furthermore, if a clip were to fall onto the metal strip transport path, it could lead to quality defects such as dents and scratches.

Furthermore, the automatic welding device for the inner diameter of a metal strip coil shown in Patent Document 4 and the method for welding the start end of a steel sheet coil shown in Patent Document 5 require a process for welding the inside of the coil and a process for cutting away the coil near the weld. For this reason, including these processes makes it difficult to insert the coil into and remove it from the pay-off reel in a short period of time, making them impractical. Furthermore, when the coil is rewound on the line, metal strip remains on the pay-off reel, causing a significant drop in yield, resulting in lost time and effort in dealing with the remaining metal strip, and requiring dedicated welding equipment, which incurs costs.

Furthermore, in the method of preventing loosening of the winding start end of a metal strip coil shown in Patent Document 6 and the method of temporarily fastening a metal strip coil shown in Patent Document 7, the adhesive adheres to the strip roll, etc., leading to quality defects such as dents and foreign matter adhesion, and if the adhesive is strong and does not peel off even when the payoff reel tail is removed, there are problems such as the same drawbacks as the above-mentioned welding fastening.
Furthermore, the method of attaching a coil to a pay-off reel shown in Patent Document 8 has a limit to how much the reel diameter can be reduced, and therefore cannot be applied when the amount of inner diameter sagging becomes large (which frequently occurs with thin metal strips). In other words, the method is insufficient for coils with a large amount of inner diameter sagging, and is therefore only applicable to coils with a small amount of inner diameter sagging. Furthermore, a dedicated device is required to automatically measure the amount of inner diameter sagging and expand/contract the reel diameter, which incurs the cost of introducing the device.

In addition, with the coil insertion method shown in Patent Document 9, the inner diameter sagging on one side is manually corrected before the coil inner diameter holding jig is fitted into the steel strip coil, which poses the problem that if the amount of inner diameter sagging of the coil is large, it is difficult to fit the coil inner diameter holding jig and the inner diameter sagging cannot be corrected. Furthermore, because the coil inner diameter holding jig is oval in shape, if the inner diameter sagging of the coil is not corrected sufficiently, the sagging part of the inner diameter may come into contact with the reel, causing defects. Furthermore, although it is said that the coil inner diameter holding jig is eventually ejected from the coil and can be recovered for repeated use, it ends up scattering if left as is, posing the problem of requiring recovery work each time.

On the other hand, the coil insertion method disclosed in Patent Document 10 can solve the problems described in Patent Documents 1 to 9.
However, in the coil insertion method disclosed in Patent Document 10, when attaching the reel drum cap to the reel drum, the reel drum cap is fixed to the reel drum using several screws, blocks, etc. As a result, a tool such as a screwdriver is required to remove the reel drum cap from the reel drum, and the removal and installation of the reel drum cap takes time. As a result, when inserting coils with different inner diameters into the pay-off reel for rewinding, the removal and installation of the reel drum cap takes time, which causes a problem of a significant decrease in production volume. As a result, the coil insertion method disclosed in Patent Document 10 is not practical for production lines where the inner diameter of the coil frequently changes and the reel drum cap needs to be removed frequently.

Furthermore, with the coil insertion method shown in Patent Document 10, the reel drum cap is fixed to the reel drum using several screws, blocks, etc., which can cause the reel drum and the reel drum cap to become misaligned. In this case, when the metal strip coil is inserted into the mandrel of the payoff reel, the inner diameter of the metal strip coil comes into contact with the reel drum cap, causing scratches or damage to the inside of the metal strip coil.

The present invention was therefore made to solve these problems, and its purpose is to provide a coil inner diameter sagging correction device and metal strip manufacturing method that can be attached and detached from the reel of a payoff reel in a short time, and that can correct inner diameter sagging that occurs on the inner diameter side of a metal strip coil without causing scratches or damage to the metal strip coil when the metal strip coil is loaded onto the mandrel of the payoff reel.

In order to solve the above-mentioned problems, one aspect of the present invention provides a coil inner diameter sagging prevention device that is attached to a payoff reel having a mandrel and reel on which a metal strip coil is supported, and that prevents inner diameter sagging that occurs on the inner diameter side of the metal strip coil. The device comprises a correction part that has an inclined surface that gradually expands in diameter from the tip to the base end, and that gradually pushes out and corrects the inner diameter sagging when the metal strip coil is loaded onto the mandrel from the tip, and a cylindrical part that is fixed to the end face on the base side of the correction part and that, when attached to the reel, The device comprises a cylindrical fitting portion that fits onto the reel, and one or more permanent magnets that are fixed to the end face of the base side of the straightening portion and attract the straightening portion to the reel when attached to the reel, the total attractive force of the one or more permanent magnets is 49.0 N or more and 147.1 N or less, the radial linear distance between the maximum radial position on the end face of the base side of the straightening portion and the radially outermost position of the one or more permanent magnets is 30 mm or more, and the fitting portion has an inner diameter that is 1 mm or more and 10 mm or less larger than the outer diameter of the reel.

In addition, another aspect of the present invention relates to a method for manufacturing a metal strip, which includes a coil rewinding process in which a metal strip coil is loaded onto a mandrel of a payoff reel using the aforementioned coil inner diameter sagging correction member, and then the metal strip coil loaded onto the mandrel is rewound.

The coil inner diameter sagging correction member and metal strip manufacturing method of the present invention can be attached to and removed from the payoff reel reel in a short time, and can correct inner diameter sagging that occurs on the inner diameter side of the metal strip coil when loading the metal strip coil onto the payoff reel mandrel without causing scratches or damage to the metal strip coil.

FIG. 1 is a schematic diagram showing a portion of a payoff reel equipped with a coil inner diameter sagging correction member according to one embodiment of the present invention, together with a portion of a metal strip coil, showing the state before the metal strip coil is loaded onto the mandrel of the payoff reel. FIG. 1 is a schematic diagram showing a portion of a payoff reel equipped with a coil inner diameter sagging correction member according to one embodiment of the present invention, together with a portion of a metal strip coil, showing the state after the metal strip coil has been loaded onto the mandrel of the payoff reel. FIG. 10 is a front view showing a state in which the coil inner diameter sagging correction member is attached to the reel of the payoff reel. FIG. 4 is a right side view of the coil inner diameter sagging correction member shown in FIG. 3 . FIG. 1 is a schematic diagram of a metal strip coil in which sagging occurs in the inner diameter.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The embodiments shown below are examples of devices and methods for embodying the technical concept of the present invention, and the technical concept of the present invention is not limited to the following embodiments in terms of the materials, shapes, structures, arrangements, etc. of the components.
In addition, the drawings are schematic, and therefore it should be noted that the relationship between thickness and planar dimensions, ratios, etc. may differ from the actual relationship, and the drawings may also contain parts where the relationship and ratio of dimensions differ from each other.

Fig. 1 shows a part of a payoff reel equipped with a coil inner diameter sagging correction member according to one embodiment of the present invention, together with a part of a metal strip coil. Fig. 1 shows the state before the metal strip coil is loaded onto the mandrel of the payoff reel. Fig. 2 shows the state after the metal strip coil has been loaded onto the mandrel of the payoff reel.
In Figs. 1 and 2, the metal strip of the metal strip coil 20 is, for example, a hot-dip galvanized steel sheet that has been subjected to annealing after cold rolling and then galvanizing.

The payoff reel 1 shown in Figures 1 and 2 is used to unwind a wound metal strip coil 20, and is equipped with a mandrel 2 and a reel 3. In this invention, "unwinding" a metal strip coil refers to stretching the coiled metal strip and paying it out onto the line.

The mandrel 2 is formed in a long, cylindrical shape, and its outer diameter can be expanded or contracted by an expansion/contraction mechanism (not shown). As shown in Figure 2, a metal strip coil 20 is loaded into the mandrel 2, which rotates to unwind the metal strip coil 20. When the metal strip coil 20 is loaded, the mandrel 2's outer diameter is reduced by the aforementioned expansion/contraction mechanism, and after the metal strip coil 20 is loaded, the outer diameter is expanded, adhering closely to the inner surface of the metal strip coil 20 and stably supporting the metal strip coil 20.

The reel 3 is fixed to one axial end of the mandrel 2 (the left end in Figures 1 and 2) and is supported by a reel support member 4, thereby supporting the mandrel 2. A drive mechanism (not shown) for rotating the mandrel 2 is provided at the other axial end of the mandrel 2. Before the metal strip coil 20 is loaded onto the mandrel 2 of the payoff reel 1, the reel support member 4 is positioned below the reel 3 as shown in Figure 1, allowing the metal strip coil 20 to be loaded onto the mandrel 2. After the metal strip coil 20 has been loaded onto the mandrel 2 of the payoff reel 1, the reel support member 4 rises as shown in Figure 2 and supports the reel 3 from below.

As shown in Figure 5, when the metal strip coil 20 is loaded onto the mandrel 2, inner diameter sagging 21, where the end of the metal strip coil 20 sags, may occur on the inner diameter portion 20a side of the metal strip coil 20. If this inner diameter sagging 21 occurs, it can become an obstacle, making it difficult to load the metal strip coil 20 onto the mandrel 2 via the reel 3 of the payoff reel 1. This inner diameter sagging 21 may interfere with the mandrel 2 or reel 3, damaging the metal strip coil 20, or the metal strip coil 20 may not fit onto the mandrel 2 and fall. This inner diameter sagging 21 is particularly likely to occur with thin metal strip materials with low rigidity.

Therefore, in this embodiment, a coil inner diameter sagging correction member 10 for correcting the inner diameter sagging 21 that occurs on the inner diameter portion 20a side of the metal strip coil 20 is attached to the reel 3 of the payoff reel 1 as shown in Figures 1 to 3.
This coil inner diameter sagging correction member 10 is attached to the reel 3 of the payoff reel 1, and corrects the inner diameter sagging 21 of the metal strip coil 20 by gradually expanding it when the metal strip coil 20 is loaded onto the mandrel 2. This prevents the inner diameter sagging 21 from interfering with the mandrel 2 or the reel 3 and damaging the metal strip coil 20.

As shown in FIGS. 1 to 4 , the coil inner diameter sagging correcting member 10 includes a correcting portion 11 , a fitting portion 12 , a plurality of permanent magnets 14 , and a handle 15 .
The straightening portion 11 is formed in a truncated cone shape and has an inclined surface 11a that gradually increases in diameter from the tip (left end in FIG. 1 ) 11b to the base end (right end in FIG. 1 ) 11c. The straightening portion 11 gradually widens and straightens the inner diameter sagging 21 of the metal strip coil 20 when the metal strip coil 20 is loaded onto the mandrel 2 from the tip 11b of the straightening portion 11 through the base end 11c and the reel 3. For this reason, the outer diameter D1 (see FIG. 3 ) of the tip 11b of the straightening portion 11 is smaller than the minor axis of the approximately elliptical inner diameter portion 20a of the metal strip coil 20 so that the metal strip coil 20 can pass through the tip of the straightening portion 11. From the viewpoint of reducing interference between the tip 11b of the straightening portion 11 and the inner diameter sagging 21 of the metal strip coil 20, it is preferable that the outer diameter D1 be 0.5 times or less the radius of the inner diameter portion 20a of the metal strip coil 20. Furthermore, from the viewpoint of further reducing interference between the tip 11b of the straightening portion 11 and the inner diameter sagging 21 of the metal strip coil 20, it is even more preferable that the outer diameter D1 be smaller than the minimum distance between the inner diameter sagging 21 and a center line connecting the radial midpoint of the metal strip coil 20. Moreover, the outer diameter D2 (see FIG. 3) of the base end 11c of the straightening portion 11 is larger than the minimum distance between the inner diameter sagging 21 and a center line connecting the radial midpoint of the metal strip coil 20 so that the inclined surface 11a can gradually push open the inner diameter sagging 21 of the metal strip coil 20 for correcting it. Moreover, it is preferable that the outer diameter D2 of the base end 11c of the straightening portion 11 is larger than the minor axis of the inner diameter portion 20a of the metal strip coil 20 so that the inclined surface 11a can gradually push open the inner diameter sagging 21 of the metal strip coil 20 for correcting it reliably.

The fitting portion 12 is a cylindrical member fixed to the end face (bottom surface) 11d of the base side of the correction portion 11, and fits onto the cylindrical reel 3 when the coil inner diameter sagging correction member 10 is attached to the reel 3 of the payoff reel 1. By fitting the fitting portion 12 onto the reel 3, the correction member 11 is fixed in the appropriate position relative to the reel 3 with high precision. The inner diameter ID (see Figure 3) of the fitting portion 12 is 1 mm to 10 mm larger than the outer diameter OD (see Figure 3) of the reel 3 to facilitate fitting onto the reel 3 and to prevent the coil inner diameter sagging correction member 10 from falling off due to rotation of the reel 3. If the inner diameter ID of the fitting portion 12 is less than 1 mm larger than the outer diameter OD of the reel 3, the fitting portion 12 cannot be easily fitted onto the reel 3. On the other hand, if the inner diameter ID of the fitting portion 12 is larger than the outer diameter OD of the reel 3 by more than 10 mm, it may not be possible to prevent the coil inner diameter sagging correction member 10 from falling off due to rotation of the reel 3. Furthermore, if the fitting portion 12 becomes too loose relative to the reel 3, the metal strip coil 20 may collide with the correction portion 11 when the metal strip coil 20 is loaded, causing damage to the metal strip.

The multiple permanent magnets 14 also attract the correction portion 11 to the reel 3 when the coil inner diameter sagging correction member 10 is attached to the reel 3. This eliminates the need to use screws or other fasteners when attaching the coil inner diameter sagging correction member 10 to the reel 3, allowing the coil inner diameter sagging correction member 10 to be attached to the reel 3 quickly and easily. The multiple permanent magnets 14 are fixed with bolts or other fasteners to a disk-shaped magnet base member 13 that is fixed to the end face 11d of the correction portion 11 on the base side, on the inner periphery of the fitting portion 12.

Here, the total attractive force of the multiple permanent magnets 14 is set to 49.0 N (5 kgf) or more and 147.1 N (15 kgf) or less, taking into consideration reducing rattle when the end of the metal band coil 20 contacts the correction unit 11 and reducing the load when removing the coil inner diameter sagging correction member 10 from the reel 3. If the total attractive force of the multiple permanent magnets 14 is less than 49.0 N (5 kgf), rattle will be significant when the end of the metal band coil 20 contacts the correction unit 11. Furthermore, this increased rattle may cause the metal band coil 20 to collide with the correction unit 11 during insertion, resulting in damage to the metal band. On the other hand, if the total attractive force of the multiple permanent magnets 14 is greater than 147.1 N (15 kgf), the load when removing the coil inner diameter sagging correction member 10 from the reel 3 is too great, making it difficult to remove the coil inner diameter sagging correction member 10 from the reel 3.

When fixing the multiple permanent magnets 14 to the magnet base member 13 (correction unit 11), as shown in FIG. 4, the multiple permanent magnets 14 are fixed to the magnet base member 13 (correction unit 11) so that the radial linear distance d between the maximum diameter position on the base end face 11d of the correction unit 11 and the radially outermost positions of the multiple permanent magnets 14 is 30 mm or more. Specifically, in this embodiment, as shown in FIG. 4, seven disk-shaped permanent magnets 14 are arranged in a ring shape around one permanent magnet 14, with six permanent magnets 14 arranged around it. The permanent magnets 14 are fixed so that the radial linear distance d between a point on the arc indicated by the dotted line connecting the radially outermost positions of the six circularly arranged permanent magnets 14 and a point on the locus of the arc of the maximum diameter position on the base end face 11d of the correction unit 11 is 30 mm or more. If the radial linear distance d is less than 30 mm, when the metal strip coil 20 is loaded onto the mandrel 2, the metal strip becomes magnetized and the end of the metal strip coil 20 on the inner diameter portion 10a side is attracted to the straightening portion 11. This causes damage such as scratches and bends to the metal strip when the metal strip coil 20 is loaded onto the mandrel 2. If the metal strip coil 20 is a steel strip coil, this type of damage is likely to occur. Therefore, by setting the radial linear distance d between the maximum diameter position on the base end face 11d of the straightening portion 11 and the radially outermost positions of the multiple permanent magnets 14 to 30 mm or more, it is possible to avoid the adverse effect of damage to the metal strip caused by magnetization of the metal strip.

In this embodiment, the metal strip coil 20 is preferably a steel strip coil with a thickness of 0.1 to 3.8 mm. Steel strip coils with a thickness of 0.1 to 3.8 mm frequently develop inner diameter sagging 21. However, by setting the radial linear distance d between the maximum diameter position at the base end face 11d of the straightening section 11 and the radially outermost positions of the multiple permanent magnets 14 to 30 mm or more, damage to the metal strip associated with magnetization of the metal strip can be suppressed and the inner diameter sagging 21 can be corrected by the straightening section 11.

A handle 15 is fixed to the end face on the tip 11b side of the correction portion 11. The handle 15 is gripped by the worker when carrying the coil inner diameter sagging correction member 10, attaching it to the reel 3 of the payoff reel 1, or removing it from the reel 3. Providing the handle 15 improves the ease and safety of carrying the coil inner diameter sagging correction member 10, attaching it to the reel 3, and removing it from the reel 3.

Next, the operation of loading the metal strip coil 20 onto the mandrel 2 using the coil inner diameter sagging correcting member 10 will be described.
First, as shown in Figure 1, with the reel support member 4 positioned below the reel 3 of the payoff reel 1, the coil inner diameter sagging correction member 10 is attached to the reel 3. At this time, the fitting portion 12 is fitted into the reel 3, and the correcting portion 11 is attracted to the reel 3 by the multiple permanent magnets 14.

Here, by fitting the fitting portion 12 to the reel 3, the correction portion 11 can be fixed in the appropriate position relative to the reel 3 with high precision. Furthermore, the inner diameter ID of the fitting portion 12 is 1 mm or more larger than the outer diameter OD of the reel 3, making it easy to fit into the reel 3. On the other hand, the inner diameter ID of the fitting portion 12 is 10 mm or less larger than the outer diameter OD of the reel 3, preventing the coil inner diameter sagging correction member 10 from falling off due to rotation of the reel 3. Furthermore, there is little play between the fitting portion 12 and the reel 3, which prevents the metal strip coil 20 from colliding with the correction portion 11 and damaging the metal strip when the metal strip coil 20 is loaded.

In addition, because the correction unit 11 is attached to the reel 3 by multiple permanent magnets 14, there is no need to use screws or the like when attaching the coil inner diameter sagging correction member 10 to the reel 3, and the coil inner diameter sagging correction member 10 can be attached to the reel 3 quickly and easily.

The total attractive force of the multiple permanent magnets 14 is 49.0 N (5 kgf) or more and 147.1 N (15 kgf) or less. Because the total attractive force of the multiple permanent magnets 14 is 49.0 N (5 kgf) or more, it is possible to reduce rattle when the end of the metal band coil 20 comes into contact with the straightening unit 11. Furthermore, by increasing this rattle, it is possible to prevent the metal band coil 20 from colliding with the straightening unit 11 when loading the metal band coil 20, thereby preventing the metal band from being damaged. Furthermore, because the total attractive force of the multiple permanent magnets 14 is 147.1 N (15 kgf) or less, the load when removing the coil inner diameter sagging correction member 10 from the reel 3 is small, allowing the inner diameter sagging correction member 10 to be removed from the reel 3 easily and in a short time.

After the coil inner diameter sagging correction member 10 is attached to the reel 3, the metal strip coil 20 is moved in the direction indicated by arrow A in FIG. 1, passing from the tip 11b of the correction portion 11 to the base end 11c and the reel 3 before being loaded onto the mandrel 2. During this process, the correction portion 11 of the coil inner diameter sagging correction member 10 gradually widens and corrects the inner diameter sagging 21 of the metal strip coil 20. This allows the inner diameter sagging 21 that occurs on the inner diameter portion 20a of the metal strip coil 20 to be corrected without causing scratches or damage to the metal strip coil 20. This reduces the difficulty of loading the metal strip coil 20 onto the mandrel 2 due to the inner diameter sagging 21 interfering with the mandrel 2 and damaging the metal strip coil 20, or the risk of the metal strip coil 20 not fitting on the mandrel 2 and falling.

Next, after the metal strip coil 20 is loaded onto the mandrel 2, the reel support member 4 is raised in the direction indicated by the arrow B in FIG. 1, and supports the reel 3 from below as shown in FIG.
Thereafter, the mandrel 2 can be rotated to unwind the metal strip coil 20 .
Then, after a coil unwinding process in which the metal strip coil 20 thus loaded onto the mandrel 2 is unwound, a metal strip product is manufactured through subsequent processes.

When the metal strip coil 20 is pulled out from the mandrel 2 of the pay-off reel 1, the metal strip coil 20 may be pulled out with the coil inner diameter sagging correction member 10 attached to the reel 3 of the pay-off reel 1.
Although the embodiment of the present invention has been described above, the present invention is not limited to this and various modifications and improvements can be made.

For example, the straightening portion 11 is not limited to a truncated cone shape, and may be a cone shape, a spherical indentation shape, a spherical truncation shape, or the like, as long as it has an inclined surface 11a that slopes so that the diameter gradually increases from the tip 11b toward the base end 11c. Even if the straightening portion 11 is a cone shape, a spherical indentation shape, or a spherical truncation shape, the inner diameter sagging 21 of the metal strip coil 20 can be gradually expanded and straightened when the metal strip coil 20 is loaded into the mandrel 2.

The number of permanent magnets 14 is not limited to seven, and may be any number other than seven, or even just one. However, the total attractive force of the one or more permanent magnets 14 must be 49.0 N or greater and 147.1 N or less, and the radial linear distance d between the maximum radial position on the base end face 11d of the correction portion 11 and the radially outermost position of the one or more permanent magnets 14 must be 30 mm or greater.

Furthermore, the metal strip of the metal strip coil 20 is not limited to hot-dip galvanized steel sheet, which is cold-rolled and then annealed, and then zinc-plated, but may also be other metal strips, such as hot-rolled steel sheet, as-cold-rolled steel sheet, cold-rolled steel sheet that has been annealed after cold rolling, electrogalvanized steel sheet that has been annealed and then electrogalvanized, tin-plated steel sheet, aluminum-plated steel sheet, etc.

To verify the effectiveness of the present invention, a metal strip coil 20 was loaded onto the mandrel 2 of the payoff reel 1 using coil inner diameter sagging correction members No. 1 to No. 16 with the specifications shown in Table 1, and the metal strip coil 20 was then unwound at a speed of 250 mpm.

The results are shown in Table 2.

The metal strip coil 20 used here had an inner diameter of 508 mm, and the metal strip was a hot-dip galvanized steel sheet with a thickness of 0.6 mm and a width of 1350 mm, with 30 mm of inner diameter sagging 21. As shown in Figure 5, the amount of inner diameter sagging of the metal strip coil 20 is the distance L between the point 20aa where a vertical line 22 drawn from the tip 21a of the sagging metal strip (inner diameter sagging 21) intersects with the inner diameter portion 10a of the metal strip coil 20 and the tip 21a of the sagging metal strip (inner diameter sagging 21).

[Evaluation of inner diameter sagging]
The coil inner diameter sagging correction members No. 1 to No. 16 used were checked for whether or not they were able to correct the inner diameter sagging. If the inner diameter sagging was corrected, it was marked as pass with a ○, and if the correction was insufficient, it was marked as fail with an ×. The correction was considered pass if the inner diameter sagging amount (distance L) of the metal strip coil described above was reduced to 1 mm or less at the time when the metal strip coil was loaded onto the mandrel 2 and the mandrel 2 was expanded in diameter. If the inner diameter sagging amount was greater than 1 mm and the metal strip coil could not be loaded onto the mandrel 2 due to contact between the inner diameter sagging 21 and the reel 3, etc., it was considered fail.

[Evaluation of Damage to Metal Strip Coil]
The coil inner diameter sagging correction members No. 1 to No. 16 used were checked for the presence or absence of damage to the end face or surface of the metal strip coil due to collision between the metal strip and the reel or the coil inner diameter sagging correction member. If there was no damage to the metal strip coil, a rating of ○ was given, and if there was damage, a rating of × was given.

[Evaluation of Damage to Metal Strip Coils Due to Magnetization of the Metal Strip]
The coil inner diameter sagging correction members No. 1 to No. 16 used were checked for the presence or absence of damage to the end face or surface of the metal strip coil due to the metal strip being attracted to the coil inner diameter sagging correction member. Whether or not the metal strip was attracted to the coil inner diameter sagging correction member was confirmed visually, and a rating of ○ was given if there was no damage to the metal strip coil, and × if there was damage.

[Evaluation of the detachability of the coil inner diameter sagging correction member]
The time required to mount the coil inner diameter sagging correction members No. 1 to No. 16 on the reels and the time required to remove the coil inner diameter sagging correction members from the reels were measured. If the members could be mounted or removed within one minute, they were given a rating of ○, and if they could not be mounted or removed within one minute, they were given a rating of ×.

[Evaluation of the stability of the coil inner diameter sagging correction member]
When the metal strip coil was loaded and unwound, the coil inner diameter sagging correcting members No. 1 to No. 16 were rated as ◯ if they could be used without coming off the reel, and x if they came off.

As is clear from Tables 1 and 2, when coil inner diameter sagging correction members No. 1 to No. 8 constituting examples of the present invention were used, inner diameter sagging could be corrected without causing damage to the metal strip coil (including damage to the metal strip coil due to magnetization of the metal strip). Furthermore, the time required to attach the coil inner diameter sagging correction members to the reel and the time required to remove the coil inner diameter sagging correction members from the reel were also short, and the coil inner diameter sagging correction members could be used without coming off the reel when loading and unwinding the metal strip coil.

In contrast, when using the coil inner diameter sagging correction member No. 9, which constitutes a comparative example and has a cylindrical correction portion 11 that does not meet the requirements of the present invention (the requirement that the correction portion have an inclined surface that gradually increases in diameter from the tip to the base), the inner diameter sagging could not be corrected (the evaluation of inner diameter sagging correction was unsuccessful).

Furthermore, when using coil inner diameter sagging correction member No. 10, which constitutes a comparative example and does not satisfy the requirement of the present invention (the requirement of having one or more permanent magnets that attract the correction portion to the reel when attached to the reel), in which the coil inner diameter sagging correction member is attached to the reel with screws, the following occurred: Due to the deterioration in the ease of attachment and detachment of the coil inner diameter sagging correction member, the time required to attach the coil inner diameter sagging correction member to the reel and the time required to remove the coil inner diameter sagging correction member from the reel became longer.

When using the coil inner diameter sagging correction member No. 11, which constitutes a comparative example and is attached to the reel 3 by fitting it onto the reel 3 using the fitting portion 12 but does not meet the requirement of the present invention of not using a permanent magnet (the requirement of having one or more permanent magnets that attract the correction portion to the reel when attached to the reel), the following occurred: The coil inner diameter sagging correction member came off the reel when loading and unwinding the metal strip coil. Furthermore, there was significant rattle when the end of the metal strip coil came into contact with the correction portion, causing the metal strip coil to collide with the correction portion 11 during loading, resulting in damage to the metal strip.

Furthermore, when using the No. 12 coil inner diameter sagging correction member, which constitutes a comparative example and uses permanent magnets but has a small total magnetic force of 1 kgf (9.8 N) and does not satisfy the requirements of the present invention (the requirement that the total magnetic force of the permanent magnets be 49.0 N or more), the following occurred: The coil inner diameter sagging correction member came off the reel when loading and unwinding the metal strip coil. Furthermore, there was significant rattle when the end of the metal strip coil came into contact with the correction unit, causing the metal strip coil to collide with the correction unit 11 during loading, resulting in damage to the metal strip.

Furthermore, when using coil inner diameter sagging correction member No. 13, which constitutes a comparative example that uses permanent magnets but has a large total magnetic force of 20 kgf (196 N) and does not satisfy the requirement of the present invention (the requirement that the total magnetic force of the permanent magnets be 147.1 N or less), the detachability of the coil inner diameter sagging correction member deteriorated, resulting in a long time required to remove the coil inner diameter sagging correction member from the reel.

Furthermore, when using the coil inner sagging correction member No. 14, which constitutes a comparative example in which the radial linear distance between the maximum diameter position on the base end face of the correction portion and the radially outermost position of the permanent magnet is short at 10 mm and does not satisfy the requirement of the present invention (the requirement that the radial linear distance be 30 mm or more), the following occurred: The magnetized metal band collided with the coil inner sagging correction member, causing damage to the metal band.

Furthermore, when using coil inner diameter sagging correction member No. 15, which constitutes a comparative example in which the inner diameter of the fitting portion is the same as the outer diameter of the reel and does not satisfy the requirement of the present invention (the requirement that the fitting portion have an inner diameter that is 1 mm or more larger than the outer diameter of the reel), the following occurred: Due to the deterioration in the attachability and detachability of the coil inner diameter sagging correction member, the time required to attach the coil inner diameter sagging correction member to the reel and the time required to remove the coil inner diameter sagging correction member from the reel became longer.

Furthermore, when using the coil inner diameter sagging correction member No. 16, which constitutes a comparative example and does not satisfy the requirement of the present invention (the requirement that the inner diameter of the fitting portion be 10 mm or less larger than the outer diameter of the reel) because the inner diameter of the fitting portion is 15 mm larger than the outer diameter of the reel, the core of the coil inner diameter sagging correction member and the reel became misaligned, causing damage to the metal strip.

REFERENCE SIGNS LIST 1 Payoff reel 2 Mandrel 3 Reel 4 Reel support member 10 Coil inner diameter sagging correction member 11 Correction portion 11a Inclined surface 11b Tip 11c Base end 11d End face on the base side 12 Fitting portion 13 Magnet base member 14 Permanent magnet 15 Handle 20 Metal strip coil 20a Inner diameter portion 21 Inner diameter sagging 21a Tip

Claims (3)

A coil inner diameter sagging correction member that is attached to a reel of a payoff reel having a mandrel and a reel on which a metal strip coil is supported, and that prevents inner diameter sagging that occurs on the inner diameter side of the metal strip coil,
a straightening unit having an inclined surface that is inclined so that the diameter gradually increases from the tip end toward the base end, and that gradually widens and straightens the inner diameter sagging when the metal strip coil is loaded onto the mandrel from the tip end;
a cylindrical fitting portion fixed to an end surface on the base side of the correction portion and fitting into the cylindrical reel when the reel is attached to the reel;
one or more permanent magnets fixed to an end surface of the base side of the straightening portion, and which attract the straightening portion to the reel when the straightening portion is attached to the reel,
a total attractive force of the one or more permanent magnets is 49.0 N or more and 147.1 N or less, and a radial linear distance between a maximum radial position on a root side end face of the correcting portion and a radially outermost position of the one or more permanent magnets is 30 mm or more,
the fitting portion has an inner diameter that is 1 mm or more and 10 mm or less larger than the outer diameter of the reel,
A coil inner diameter sagging correction member, characterized in that the outer diameter of the root end of the correction portion is larger than the minor axis of the inner diameter portion of the metal strip coil . The coil inner diameter sagging correction member described in claim 1, characterized in that the correction portion has one of the following shapes: a cone shape, a truncated cone shape, a spherical notch shape, and a spherical truncated shape. A method for manufacturing a metal strip, comprising a coil rewinding process in which a metal strip coil is loaded onto a mandrel of a payoff reel using the coil inner diameter sagging correction member described in claim 1 or 2, and then the metal strip coil loaded onto the mandrel is rewound.