JP2845121B2 - Plate shape control method and apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel rolling method and apparatus capable of performing rolling and shape correction of a sheet.

[0002]

2. Description of the Related Art In recent years, flatness requirements for rolled steel strips and plates have become increasingly strict, and users have demanded a steepness of 0.2% or less for thin plates and a wave height of 2 mm or less for thick plates. Is coming.

[0003] Against this background, in recent years, the development of a shape control mechanism for a rolling mill has been advanced, and the following methods have been proposed.
Both have been put to practical use. The work roll is bent by a bender to control the shape. The crown is made variable and its shape is controlled by applying an internal pressure by hydraulic pressure using a backup roll as a sleeve structure. The shape is controlled by a multi-stage roll represented by an HC mill. The roll is crossed in the rolling direction to change the roll gap shape.

However, at present, it is difficult to realize a flatness having a steepness of 0.2% or less even with a rolling mill having a conventional shape control mechanism. That is, in the conventional techniques, all methods control the force applied to the roll or apply an external force to the roll to control the elastic deformation of the roll. However, the following points are essentially difficult. The rolling strain distribution is 1 × 10 ^{-6 in} the width direction distribution of the roll gap.
It must be controlled with a high degree of accuracy (within a steepness of 0.2%). The accuracy of the output of the shape meter, which is the control input, is poor.

[0005] Therefore, in order to satisfy the demands of users, flatness cannot be achieved unless a thick plate is passed through a leveler or press, and a thin plate is passed through a tension leveler or a temper rolling line.

[0006] From the above point, in the prior art, 0.2%
It is difficult to achieve the following steepness, and as a measure against this, install a tension leveler or leveler near the mill,
The following rolling equipment is disclosed as a rolling equipment for correcting shape defects that cannot be removed by a rolling mill using these auxiliary devices.

[0007] The technique described in Japanese Patent Application Laid-Open No. 51-44551 is to provide a leveler including three straightening rolls whose roll diameters sequentially increase in the direction of the strip approach at the rear of the rolling mill, and simultaneously with plastic elongation. This is a method for correcting the residual curvature.

[0008] The technique described in Japanese Patent Application Laid-Open No. 59-94504 discloses a technique in which a roller of a group of bending rollers arranged on the entrance side of a plate mill is rotated at a speed lower than the peripheral speed of a rolling work roller. By applying a tension to the material, the bending of the plate material is prevented, and the rollers of the bending roller group arranged on the output side of the plate mill are rotated faster than the peripheral speed of the rolling work roll, so that the plate material is rotated. This is a method of improving the flat shape of the plate material by applying tension.

The technique described in Japanese Patent Application Laid-Open No. 60-56402 includes a leveling mill and, if necessary, a bridle between a final stand of a cold rolling facility or a temper rolling facility and a winding device. A cold rolling line arrangement in which a tension leveler is installed. The aim is to streamline the line arrangement and reduce equipment costs and running costs.

The technique described in Japanese Patent Application Laid-Open No. 61-212410 is a skin pass mill characterized by attaching a tension leveler to a part of a housing on an outlet side of a rolling mill. It is an object of the present invention to obtain a skin pass mill that can be effectively used to produce metal strips from thin to thick ones at low cost.

[0011]

However, in the above-mentioned prior art, there is a problem that the expected shape correcting ability is not always obtained. The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a most effective shape control method and apparatus using a combination of a rolling mill and a leveler.

[0012]

The above object is achieved by the following means. What is claimed is: 1. A method for controlling the shape of a plate, comprising controlling the shape of the plate to a medium elongation or a quarter wave shape with a rolling mill, and correcting the shape with a subsequent leveler or tension leveler. What is claimed is: 1. A shape control device for a plate, wherein a rolling mill for forming a medium elongation or quarter wave shape is directly connected to a leveler or a tension leveler for correcting the shape.

[0013]

The operation of the present invention will be described below. FIG.
It is a shape control result of a tension leveler in a device in which a rolling mill and a tension leveler are directly connected as a shape control of a thin plate. If the shape in the rolling mill is not medium elongation or quarter elongation, the steepness does not fall within 0.2% even if the elongation rate in the tension leveler is increased to 1%, and elongation of 0.5% or more in medium elongation and quarter elongation Is given by the tension leveler, it can be said that the steepness falls within 0.2%.

FIG. 3 shows the shape control result of a plate mill in which a rolling mill and a leveler are directly connected. The device here is used for a hot plate such as a thick plate (for example, in front of an accelerating cooling device), and the leveler is an image of a rough leveler of the type that bites a roller, and there is no need to have a difference in peripheral speed. It is good if it can be restrained. As compared with the plastic deformation rate given by the leveler on the output side from FIG. 3, the middle stretched shape is also easier to flatten the shape. Also, it is understood that the plastic deformation rate given to the plate needs to be 0.8 or more.

The reason why these tension levelers and levelers are more elongated than the ear waves and are effective in correcting the quota wave is that the tension levelers and the leveler have a weak winding at the width end portion which is the ear wave portion and have a plate shape. Can also escape to the side, so the binding force is weak. On the other hand, since the restraining force is strong at the center of the width where the middle elongation and the quarter wave occur, the correcting force is high.

The following findings are obtained from the above results. Basically, it is possible to correct a shape defect generated in a rolling mill with a connected tension leveler (or leveler). However, even if the same pushing amount is given by the tension leveler (or the leveler), the shape correcting effect differs depending on the shape coming out of the rolling mill. The shape after rolling, which has a high shape correcting effect with a tension leveler (or leveler), is in the order of quarter wave, middle elongation, and ear wave. It is very difficult to reduce the eaves shape after rolling to 0.2% or less in steepness even if the elongation at the tension leveler is 1% or more, or the indentation at the leveler is plastic deformation rate 0.8 or more. It is.

From the above findings, if the shape coming out of the rolling mill is a quarter wave and a medium elongation, it is possible to correct the steepness to 0.2% or less by a tension leveler (or leveler). Therefore, the shape control method according to the present invention is as simple as forming a medium elongation or a quarter wave by a rolling mill and then pushing in a directly connected tension leveler (or leveler) roll. Further, the configuration of the apparatus according to the present invention includes, as functions of the rolling mill, simply a rolling mill capable of reliably forming a medium elongation or a quarter wave shape, and a leveler capable of repeatedly bending or a tension leveler capable of applying tension. Just do it.

[0018]

An embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows an embodiment of the apparatus configuration of the present invention, in which a 4Hi temper mill and a tension leveler are directly connected.
In FIG. 1, 1 is a work roll, and 2 is a backup roll. Reference numeral 3 denotes a tension leveler, and the type shown in the figure is inexpensive as the type of the tension leveler. 4 is a warp straightening roll, 5 is a coil before rolling, 8 is a coil after rolling, and shows both upper winding and lower winding cases. Reference numeral 6 denotes an entrance bridle roll, and reference numeral 7 denotes an exit bridle roll. When a bridle roll is provided before and after the tension leveler, tension (elongation) adjustment and tension adjustment with a skin pass mill (temper mill) are facilitated. It will be expensive.

In the present embodiment, offline
The relationship between the elongation rate and the elongation rate of the skin pass and the indentation amount of the leveler should be grasped by the output side tension before use. Table 1 shows the specifications of the rolling mill in this embodiment.

[0020]

[Table 1]

Table 2 shows the specifications of the tension leveler in this embodiment.

[0022]

[Table 2]

Table 3 shows the specifications of the material to be rolled in this embodiment.

[0024]

[Table 3]

FIG. 4 shows the shape control capability of this embodiment (with 4Hi work roll double tick bender).
FIG. 4 is a view showing a range in which the shape of an original sheet can be corrected by a rolling mill. In FIG. 4, the shaded area indicates the shape range of the steepness of the original sheet after rolling by the rolling mill of the present invention. It can be seen that this mill can sufficiently control the shape on the exit side of the rolling mill to a middle stretch shape. Here, the control is mainly performed by using an increase bender for narrow width materials, and mainly by a Decrease bender so as not to narrow down the board with a large middle elongation for wide width materials. For example, for 600mm width material, the inner is 70 tons of outer
For ton and 1500mm width material, the inner decrees was controlled by 70ton and outer 0ton by bender force.

As shown in FIG. 2, a plate having these shapes is subjected to elongation control of 0.5% or more by a tension leveler on the exit side of the rolling mill to produce a plate having a steepness of 0.2% or less for a full width plate. It became possible. FIG. 5 is a diagram showing an apparatus configuration according to the present invention.
In this embodiment, a 4Hi plate mill and a leveler are directly connected. 5, the same parts as those in FIG. 1 are denoted by the same reference numerals, and the description will be omitted. Table 4 shows the specifications of the rolling mill in this embodiment.

[0027]

[Table 4]

Table 5 shows the specifications of the leveler in this embodiment.

[0029]

[Table 5]

Table 6 shows the specifications of the material to be rolled in this embodiment.

[0031]

[Table 6]

FIG. 6 is a diagram showing a range in which the shape control capability of the rolling mill according to the present embodiment can correct the shape of the original plate. It is a shape range of the steepness of the original sheet after rolling is performed by the rolling mill of the present invention. According to FIG. 6, even if the original plate is an ear wave, the plate width is 1800.
It can be seen that it is corrected over a wide range of ~ 5000 mm. FIG. 7 shows the shape on the exit side of the apparatus according to the present embodiment. As can be seen from FIG. 7, the steepness falls below 0.2% for all widths.

FIG. 8 shows a BUR chamfer employed in this embodiment so that the rolling mill can stably form a middle stretched shape. As for the mill shape control, the bender is operated at full capacity when the width is narrow, and the bender is not used for the wide material. That is, here, 18
Increments were 310 tons for 00 mm wide materials, and 0 tons of bender force for materials with 350 mm width or more. The leveler is controlled so that each width is constant with a pushing amount of 10 mm, and the pushing amount of the delivery roll is set to 0 mm so that warpage does not occur.

FIG. 9 shows an embodiment different from FIGS. 1 and 5 of the apparatus configuration of the present invention, in which a 2Hi large crown work roll temper mill and a tension leveler are directly connected. In FIG. 9, the same parts as those in FIG.
Description is omitted. Table 7 shows the specifications of the rolling mill in this embodiment.
Shown in

[0035]

[Table 7]

Table 8 shows the specifications of the tension leveler in this embodiment.

[0037]

[Table 8]

Table 9 shows the specifications of the material to be rolled in this embodiment.

[0039]

[Table 9]

FIG. 10 is a view showing the shape on the exit side when the shape of the entrance side plate is flattened according to the present embodiment. It can be seen from the present example that the shape at the exit side of the rolling mill can be made into a middle stretch shape. In addition, the elongation of the sheets having these shapes was controlled at 0.4% or more by the tension leveler on the exit side of the rolling mill, and it became possible to manufacture sheets having a steepness of 0.2% or less with respect to the entire width of the sheet. As shown in this example, it can be seen that in the present invention, a flat plate can be obtained even with a 2Hi mill having a simple large crown work roll.

As described above, it is understood that the present rolling shape control method does not require an advanced shape control mechanism on the rolling mill side, and that a flat plate can be easily obtained on the leveler side by simple control.

[0042]

As described above, according to the present invention, as a control method, a simple method such as controlling the plate shape to medium elongation by a rolling mill and elongating the leveler at a certain level or more is provided. In addition, as a shape control device, by simply attaching a mechanism that generates medium elongation to the rolling mill and directly connecting the leveler mechanism to configure the device, the shape is measured as in the past and fed back, and the rolling is performed. There is an effect that a flat plate can be easily obtained at low cost without requiring a complicated control method such as controlling various roll deformation control actuators of the machine.

[Brief description of the drawings]

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

FIG. 2 is a view showing a shape control result of the tension leveler of FIG. 1;

FIG. 3 is a diagram showing a shape control result by the leveler of FIG. 5;

FIG. 4 is a view showing a range in which the shape of an original sheet can be corrected by a rolling mill having a shape control ability in the embodiment shown in FIG. 1;

FIG. 5 is a view showing an embodiment of the apparatus configuration of the present invention which is different from FIG. 1;

FIG. 6 is a view showing the shape control capability of the rolling mill according to the embodiment of FIG. 5 having the apparatus configuration of the present invention.

FIG. 7 is a diagram showing a configuration of the apparatus configuration of the present invention according to the embodiment of FIG. 5;

FIG. 8 is a block diagram of a device B according to the embodiment of FIG.
The figure which showed the UR chamfer.

FIG. 9 is a view showing an embodiment of the apparatus configuration of the present invention which is different from FIGS. 1 and 5;

FIG. 10 is a diagram showing a shape of a rolling mill exit side according to the embodiment of FIG. 9 having the apparatus configuration of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rolling work roll 2 Rolling backup roll 3 Tension leveler (or leveler)

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-57-202904 (JP, A) JP-B-48-39356 (JP, B1) JP-B-53-48182 (JP, B2) (58) Field (Int.Cl. ⁶ , DB name) B21B 37/28

Claims (2)

(57) [Claims] 1. A method for controlling the shape of a sheet, wherein the shape of the sheet is controlled to a medium elongation or a quarter wave shape by a rolling mill, and the shape is corrected by a subsequent leveler or tension leveler. 2. A shape control device for a plate, wherein a rolling mill for forming a middle elongation or a quarter wave shape and a leveler or a tension leveler for correcting the shape are directly connected.