JPH07292422A - Device for carrying metal strip - Google Patents

Abstract

PURPOSE:To prevent the development of buckling of a metal strip near carrying rolls, in a continuous annealing furnace, etc., for metal strip. CONSTITUTION:In an installation for carrying the metal strip 2 while hanging the metal strip a cross plural carrying rolls 1, an auxiliary roll 9 having the roll length shorter than the width of the metal strip is arranged at the inlet side or the outlet side of the metal strip 2 to the carrying roll 1 as parallel to the carrying roll 1, and the mechanism for pushing the auxiliary roll 9 to the metal strip 2 is arranged. By this constitution, the passable range of the metal strip in the continuous annealing furnace, etc., is enlarged, and it has the effect that contributes to improve the quality of the product and also, the productivity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conveying device for correcting a wrinkle shape generated in a steel strip in a facility for transporting a metal strip (steel strip or the like) while being stretched over a plurality of transport rolls.

[0002]

2. Description of the Related Art In equipment (eg, continuous heat treatment furnace, looper device, etc.) for transporting a steel strip while it is stretched over a plurality of transport rolls, the problem of meandering of the steel strip from the center of the transport path line and the strip There is a problem of buckling that causes wrinkles (out-of-plane deformation of the steel strip, which includes elastic deformation and plastic deformation).

In order to prevent the meandering of the steel strip, conventionally, a steering roll having a meandering correction mechanism is arranged for every 5 to 10 conveying rolls, but since the steering roll is expensive, it is installed. The number was limited and it was not possible to effectively prevent meandering.

FIG. 4 is a view showing a conventional transport roll for preventing such meandering. Fig. 4 (a) shows a conveyor roll with a taper (taper height: H).
Fig. 4 (b) shows a conveyor roll with a curved crown (crown height: h), which is inferior to the steering roll in terms of the meandering correction speed, but the same principle is used to prevent meandering in a belt car. It has a meandering prevention function. However, if the taper height H and the crown height h of the transport roll are too high, the meandering correction force acting on the steel strip becomes excessive, compressive stress is generated in the steel strip width direction, and the out-of-plane deformation of the steel strip occurs. Occurs. When the steel strip is wound around the transport roll with out-of-plane deformation, the steel strip buckles and wrinkles on the transport roll, detracting from its value as a product and when the buckling is severe. Due to this, the steel strip may be squeezed and broken, which may cause serious troubles such as operation stop of the equipment.

If the taper height H and the crown height h of the transport roll are reduced, buckling can be avoided, but since it becomes easy to meander, it is desired to establish a technique for simultaneously preventing both.

In order to solve such a problem, Japanese Unexamined Patent Publication No. 59-80734 discloses that a steel strip is conveyed in parallel with the conveying roll and its length immediately before and after winding the steel strip around the conveying roll. A method is disclosed in which an auxiliary roll having the same cylindrical shape as the roll is installed to straighten the deformation of the steel strip. FIG. 5 is a diagram showing an example of such a method.
In the figure, 1 is a transport roll, 2 is a steel strip, 3 is a conventional auxiliary roll, and 8 is out-of-plane deformation after passing through the auxiliary roll.
In FIG. 5, the arrow indicates the conveying direction of the steel strip 2.

Further, in Japanese Patent Laid-Open No. 5-186837, a cylindrical auxiliary roll having the same length as the conveying roll is installed immediately before winding the steel strip around the conveying roll. Of the steel strip width of 0.7 ~ 5
By doubling the number, a method is disclosed in which wrinkles occurring in the steel strip are corrected while being corrected into a flat shape and then conveyed. FIG. 6 is a diagram showing an example of such a method. In the following figures, the same parts as those in FIG. 5 are designated by the same reference numerals and the description thereof will be omitted. In FIG. 6, L is the distance between the transport roll and the auxiliary roll. Further, the arrow indicates the conveying direction of the steel strip 2.

[0008]

However, the above-mentioned prior art has the following problems. When the width of the steel strip is wide and the plate thickness is thin, and the tension acting on the steel strip to prevent the meandering of the steel strip becomes large, the out-of-plane deformation of the M-shape will occur largely before the auxiliary roll. Become. JP-A-59-
In the auxiliary roll having the same length as the transport roll as described in Japanese Patent No. 80734, the movement of the steel strip in the width direction is restricted, and the steel strip deformed in such a large M shape is the auxiliary roll. When entering, there is a problem that the auxiliary roll itself causes buckling of the steel strip.

The method described in JP-A-5-186837 is basically the same as the method described in JP-A-59-80734. Not only the deformation cannot be sufficiently corrected, but also the auxiliary roll itself causes a buckling of the steel strip.

In view of the above problems, the present invention optimizes the steel strip deformation correcting mechanism based on a steel strip deformation correcting experiment near the conveying roll to avoid buckling of the steel strip on the conveying roll. A carrier device is provided.

[0011]

The above-mentioned problems can be solved by the following means. In equipment that transports metal strips while spanning multiple transport rolls, an auxiliary roll that is parallel to the transport rolls and has a roll length shorter than the width of the metal strips is provided on the inlet side or the outlet side of the metal strips. A metal strip transporting device comprising a mechanism for pressing the auxiliary roll against the metal strip. In equipment for transporting metal strips while spanning a plurality of transport rolls, an auxiliary roll provided with a convex crown in parallel to the transport rolls on the inlet side or the outlet side of the metal strips is provided. A device for transporting a metal band, which is provided with a mechanism for pressing a roll against the metal band. In the above-described transport device, the auxiliary roll is provided with a mechanism capable of moving in the width direction of the metal strip.

[0012]

The present inventors have found that the shape of the transport roll, the width of the steel strip,
Through experiments with varying thickness, the relationship between the shape of the out-of-plane deformation occurring in the steel strip immediately before the winding of the transport roll and the buckling on the transport roll was clarified. FIG. 7 is a diagram showing the relationship between the shape of such out-of-plane deformation and the buckling on the transport roll. In FIG. 7, 9 is an auxiliary roll according to the present invention. In this case, the auxiliary roll is provided on the entrance side of the transport roll, but the same relationship can be obtained when it is provided on the exit side.

As shown in FIG. 7, when a taper taper roll is used as the conveying roll 1 and the taper height is constant, as shown in (A) while the tension applied to the steel strip 2 is small, C-shaped out-of-plane deformation occurs in the steel strip 2. Further, even if the carrier roll is wound around in such an out-of-plane deformation state, it will not buckle. When the tension applied to the steel strip 2 increases, the M-shaped out-of-plane deformation occurs in the steel strip 2 as shown in (B). Here, T indicates the top of the M type. The out-of-plane deformed shape of the steel strip 2 changes from the C type to the M type because the tensile stress applied to the steel strip 2 increases and the transverse compressive stress generated in the steel strip increases. This is because the swelling of the C-shaped deformation is restrained due to the action of. Then, the deformation amount S of the M-shaped out-of-plane deformation in the vicinity of the contact start point with the transport roll increases as the tension increases,
In this experiment, it was revealed from the experiment that when the deformation amount S exceeds about 2 mm, buckling occurs in the steel strip 2 as shown in (C). The cause of this buckling is considered to be that when the tensile tension in the longitudinal direction increases, the frictional force between the steel strip 2 and the transport roll 1 increases, and the movement of the steel sheet in the width direction on the roll is restricted. .

On the other hand, even when the tension is large and the deformation amount S exceeds about 2 mm, the deformation of the central portion of the steel strip is pressed by the auxiliary roll 9 provided with the convex curved crown as shown in (D). If the M-type out-of-plane deformation is corrected to the C-type out-of-plane deformation,
Experiments have revealed that buckling is less likely to occur. This is considered to be the result of the change in the compressive stress distribution inside the steel strip due to the shape correction by the auxiliary roll 9 according to the present invention. Further, in order to correct the M-shaped in-plane deformation to the C-shaped in-plane deformation, the length of the auxiliary roll is preferably 0.75 times or less and 0.5 times or more of the maximum strip width of the steel strip. There was found. That is, although the out-of-plane deformation of the steel strip remarkably occurs in the wide material, in the M-shaped deformation that requires the shape correction by the auxiliary roll, the interval W _T between the M-shaped top portions T in FIG. 7 is about the plate width. It is 0.5 times, and the length of the auxiliary roll for correcting the shape of this portion to be C-shaped needs to be 0.5 times or more the plate width. Further, if the auxiliary roll is too long, the escape in the width direction near both ends of the steel strip is restricted, so that it is easy to cause drawing where the steel strips overlap during plastic deformation during buckling. It became clear that it was not restricted if it was 0.75 times or less of the plate width. In the case of a narrow material, the length of the auxiliary roll is 0.75 times the plate width or more, but there is no problem with the narrow material because out-of-plane deformation is difficult to occur and it is difficult to squeeze.

FIG. 8 is a diagram showing a situation in which an aperture is generated when the length of the auxiliary roll with respect to the plate width is changed. When the length of the auxiliary roll is 0.5 to 0.75 times the sheet width, the aperture is generated. There is no, and the result is good.

In contrast to the present invention, the prior art (Japanese Patent Laid-Open No. 59-8)
Comparative method with the method described in Japanese Patent No. 0734), the conventional technique restrains the movement of the steel strip in the width direction by the auxiliary rolls, especially when the thickness of the steel strip is thin and wide. Therefore, it was found that buckling is more likely to occur as compared with the case where an auxiliary roll having a length shorter than the width of the steel strip is installed as in the present invention. That is, in the conventional technique, as shown in FIG.
As shown by the out-of-plane deformation 8 after passing through the auxiliary roll in
The out-of-plane deformation of the steel strip after shape correction is M-shaped, and not only the deformation has not been corrected sufficiently, but the auxiliary roll itself also causes the widthwise movement of the steel plate to be restrained. It has not been resolved.

On the other hand, according to the method of the present invention, the shape of only the widthwise central portion of the steel strip is corrected to the C-shaped out-of-plane deformation in which buckling is less likely to occur, and the roll length is steel. Since the width is shorter than the width of the strip, the deformation in the width direction of the steel strip is not restricted, the deformation in the width direction of the steel strip in the vicinity of the transport roll is free, and buckling is less likely to occur.

Further, when the crown shape of the auxiliary roll is a convex curved crown, the out-of-plane deformation of the steel strip is corrected to a smooth C-shaped out-of-plane deformation by pressing the auxiliary roll, and the auxiliary roll and the steel strip. Since the distribution of the contact pressure of No. 2 is large at the central portion of the auxiliary roll and small at the end portion, the deformation in the width direction of the steel strip is not restricted. Similar results can be obtained when the convex crown of the auxiliary roll is a tapered taper crown, but there is a problem that the steel strip is easily flawed at the taper start portion of the roll. Although this problem can be improved by providing a gentle curvature at the taper start portion, it is preferable to give a curled crown to the entire roll.

The distance from the contact start position of the transport roll and the steel strip to the auxiliary roll is preferably at least the length of the auxiliary roll. This is because if the distance from the contact start position of the transport roll and the steel strip to the auxiliary roll is too short, the stress distribution generated near the transport roll will affect the auxiliary roll position, and the shape of the auxiliary roll with a small winding angle will be affected. This is because the correction effect is attenuated.

Further, by making the auxiliary roll movable in the width direction of the steel strip, the shape correction effect of the auxiliary roll is maintained even when the out-of-plane deformation of the steel strip occurs asymmetrically in the width direction of the steel strip. be able to.

[0021]

Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a view showing an embodiment of the present invention, and is a side sectional view in the case where an auxiliary roll is experimentally applied to the entrance side of a conveying roll in a continuous annealing furnace for steel strips. In FIG. 1, 4 is a furnace shell, 5 is a viewing window for observation, and 9 is an auxiliary roll according to the present invention. Here, the transport direction of the steel strip 2 is from a to b. The transport roll 1 and the auxiliary roll 9 are made of steel, and the diameter of the transport roll is 1 m. The diameter of the central portion of the auxiliary roll 9 is 0.4 m, and the length is 1 m. The maximum pushing amount d of the auxiliary roll 9 is 5 from the pass line.
It can be installed by changing it within the range of 0 mm, and ± in the width direction of the steel strip.
The structure is such that it can move 100 mm. The distance L between the transport roll 1 and the auxiliary roll 9 is 1.5 m based on the experimental result.
I am trying.

FIG. 2 is a view seen from the direction of arrow A in FIG.
is there. In the following figures, the same parts as those in FIG.
The description is omitted. In FIG. 2, 6 is an auxiliary roll
9 is a moving device, and 7 is a sealing bellows. See also W_HIs complementary
The length of the auxiliary roll 9 is W _SIs the strip width. In the experiment
Is a TV camera as a detector for detecting out-of-plane deformation.
La is installed in the peep window, and while watching the screen, the auxiliary roll position
The device is operated manually. The auxiliary roll 9 has a convex
A curved crown is added, and the crown height h is 2 m
m.

FIG. 3 is a view showing the range of possible buckling-free threading according to the present invention in comparison with the prior art. In the following figures, the same parts as those in FIG. In FIG. 3, the horizontal axis represents the dimensionless plate width (W _S /
W ₀ ) and the vertical axis represents the dimensionless plate thickness (t / t ₀ ). Here, W ₀ is the standard value of the steel strip width, t is the plate thickness, and t ₀ is the standard value of the plate thickness. The area indicates the range of threading possible when only the transport rolls shown in FIG. 4 are used. Further, the area indicates the range of threading possible when the conventional auxiliary roll shown in FIG. 5 is used. The area indicates a further area where the plate can pass further when the auxiliary roll according to the present invention is used. As shown in FIG. 3, when only the conventional transport roll is used, the thick plate area is
Further, in the case of using the auxiliary roll of the prior art, it is possible to pass a narrow strip area, whereas according to the present invention,
It can be seen that the strip can be passed in a region where the strip width is wide and the strip thickness is thin.

[0025]

As described above, according to the present invention, the range in which strips can be passed in a continuous annealing furnace or the like is expanded, and there is an effect of not only improving the quality of products but also improving productivity.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention.

FIG. 2 is a view of the embodiment of FIG. 1 viewed from the direction of arrow A.

FIG. 3 is a diagram showing a range in which buckling-free threading according to the present invention is possible, in comparison with a conventional technique.

FIG. 4 is a diagram showing an example of a transport roll according to a conventional technique.

FIG. 5 is a diagram showing an example of an auxiliary roll according to the prior art.

FIG. 6 is a view showing an embodiment different from FIG. 5 of the auxiliary roll according to the prior art.

FIG. 7 is a diagram showing the relationship between the shape of the out-of-plane deformation and the buckling on the transport roll.

FIG. 8 is a diagram showing a situation in which a diaphragm is generated when the length of the auxiliary roll with respect to the plate width is changed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Conveying roll 2 Steel strip 6 Auxiliary roll moving device 9 Auxiliary roll according to the present invention

Claims (3)

[Claims] 1. A facility for transporting a metal strip while spanning a plurality of transport rolls, wherein the metal strip is parallel to the transport roll at the entrance side or the exit side of the transport strip, and the roll length is greater than the width of the metal strip. A metal strip conveying device comprising a short auxiliary roll and a mechanism for pressing the auxiliary roll against the metal strip. 2. A facility for transporting a metal strip while being stretched over a plurality of transport rolls, wherein an auxiliary roll provided with a convex crown parallel to the transport roll on the inlet side or the outlet side of the metal strip. And a mechanism for pressing the auxiliary roll against the metal strip. 3. The transporting device for the metal strip according to claim 1, wherein the auxiliary roll is provided with a mechanism capable of moving in the width direction of the metal strip.