JPS6281202A - Method and apparatus for cold rolling for thin sheet - Google Patents

Abstract

PURPOSE:To suppress the generation of edge drop and to improve the thickness accuracy and yield of a product by applying a specific cross rolling reduction to a material to be rolled from the transverse direction thereof to form dogbones at the edges of the material to be rolled, then subjecting the material to be rolled to horizontal rolling. CONSTITUTION:The material 1 which is to be rolled and is let off from a payoff reel 6 is cross rolled down by two sets of vertical rolls 9, 9, by which the cross rolling reduction twice large than the sheet thickness is applied thereto. The dogbones 1a are thereby formed to the edges of the material 1. The material 1 is thereafter rolled by a horizontal rolling mill 5 and therefore, the edge drop of the product is decreased. As a result, the sheet thickness accuracy of the product is improved and the yield in the rolling stage is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a cold rolling method and apparatus for forming a thin metal sheet with a small edge drop.

(Prior Art) Normally, when a plate material is formed by rolling, the shape of the plate material is defective due to roll-induced deformation. To explain this with reference to FIGS. 4 and 5, the rolled material L that has been rolled with elastic deformation of the L roll has a thickness (
A difference inevitably occurs between the thickness (he) of the edge portion and the plate thickness (he) of the edge portion. This difference (he −he) is the plate crown (C
s). In the figure, arrow St indicates rolled material l
is the rolling direction.

When the L foot plate crown (Cs) is large, the proportion of the plate crown (Cs) in the rolled material l becomes large compared to a rectangular plate cross section (shown by the dotted chain line in Figure 5). . For this reason, not only is the yield undesirable, but also shape defects such as elongation are likely to occur during subsequent rolling.

Therefore, in order to reduce the plate crown (Cs),
A call-hending method, a roll shift method, a crown variable roll control method, etc. are all known.

By the way, due to the complicated three-dimensional deformation of the material to be rolled 1, the contact pressure between the rolling roll and the material to be rolled u1 changes rapidly at the edge and the edge portions of the material to be rolled 1 during wet rolling. An error (E) (shown in Figure 614) occurs.

This is said to be caused by the fact that the rolled material 1 flows in its width direction during horizontal rolling, resulting in so-called width expansion, which causes the edge portion to become relatively 71λ11. However, this work.

Since conventional methods have almost no effect on G. rosso (E), this method is currently used. / The part (E) is trimmed to form the product.

In order to effectively control encitrotubules (E),
After horizontal rolling of the material 1 to be rolled, width reduction is performed using vertical rolls to preliminarily increase the thickness of the edge portion of the material 1 to be rolled, forming a so-called dog bone.
) is being considered.

To explain this point, Fig. 7 shows the center of the rolled aluminum material 1 with a plate thickness of 3 mm after one pass of width reduction with vertical rolls and then one pass of wet roll rolling. It shows the relationship between the difference between the part plate thickness (he) and the edge part plate thickness (he) and the width reduction amount (edging amount: ΔE). According to this, it can be seen that as the edging amount (ΔE) is increased, the edge portion relative plate thickness (he − ha) after one pass can be increased in the positive direction (edge-up direction).

”-, the relative thickness of the edge portion (he −hc
) was horizontally rolled in the same way as normal cold rolling, and the edge portion relative thickness (he-he) was determined as 4111 for each bath during finishing to the final product. It is shown in Figure 8. According to this, the large edge-part opposing plate Iv (he-hc) formed at the beginning rapidly decreases as the horizontal rolling passes progress, and the difference between the final product and the conventional method is extremely small. Recognize. Therefore, in order to obtain a cold-rolled metal sheet with a smaller edge drop (E) than the conventional method, it is necessary to form the sheet at the initial stage. The relative plate thickness of the hex portion (he - hc) is required to be very large.

By the way, in ordinary en-rolling for forming dog bones, the maximum width that can be obtained in one pass is approximately equivalent to the thickness of the plate.Moreover, in the case of this cold-rolled thin metal sheet, Although the plate is thin, the yield stress is high and buckling or floating occurs easily, so the plate thickness is 3111.
In the case of ffl, maximum width reduction is possible using the above conventional method.
The distance is 1 o + m.

It cannot even reach the intestine of plate pressure.

Therefore, in order to solve the problem described in "-", it is necessary to add more Ij to the material to be rolled to suppress the occurrence of buckling. Maximum width can be reduced by restraining material 1”
Methods have already been proposed to bring about this.

The method of applying the tension shown in 1 is as shown in Figure 9.
The maximum width that can be reduced can be reduced to about 2 times. Similarly, the method of restraining with pinch rolls is also used in the 10th
As shown in the figure, this method is about as effective as applying tension.

However, even if these methods are used.

It is not possible to obtain a width reduction as large as shown in FIG.

(Objective of the Invention) This invention was made in view of the above-mentioned circumstances, and it forms larger tongue pawns at the edges of the rolled material, thereby effectively suppressing the occurrence of edge drops and improving the product plate. The purpose is to improve thickness accuracy and yield during rolling.

(Structure of the Invention) - The feature of this invention to achieve the desired result is that during the rolling process of the material to be rolled, the material to be rolled is The method is to apply a width downstream amount to form a dog bone at the edge of the material to be rolled, and then perform horizontal rolling on the material to be rolled. In addition to installing a tensioning device that applies tension to the material being rolled between machines,
A plurality of restraint mechanisms are provided along the rolling direction to sandwich the material to be rolled in this portion from above and below, and vertical rolls are provided for rolling down both side surfaces of the material to be rolled, respectively, in the vicinity of these restraint mechanisms.

(Example) Hereinafter, an example of the present invention will be described with reference to FIGS. 1 to 3.

In the figure, reference numeral 5 denotes a horizontal rolling mill, and a payoff reel 6 is provided on the inlet side of the floating rolling mill 5 to continuously supply the material to be rolled. Further, a tension roller roll 7 is interposed between the horizontal rolling mill 5 and the payoff reel 6 as a tension applying device for applying backward tension to the material 1 to be rolled. Further, a width reduction device 8 for the material to be rolled 1 is provided between the horizontal rolling mill 5 and the payoff reel 6 on the entry side of the horizontal rolling mill 5.

The width reduction device 8 applies 2Mi width reduction to the rolled material l.
It is composed of a vertical roll 9.9 and a restraining mechanism 11 provided in the same longitudinal section including the axis of the vertical roll 9 and sandwiching the rolled material l from the northward direction.

Although not shown in the drawings, a roll opening adjustment device for the vertical rolls 9 is provided, and the restraint mechanism 11 includes a pair of edge pinch rolls 12 that sandwich the edge portion of the material to be rolled 1 from below; It is composed of a pair of center portion pinch rolls 13 that pinch the center portion from below. 14 is a guide roll that guides the material to be rolled 1 to the horizontal rolling mill 5 and the width reduction device 8.

Each vertical roll 9 has a maximum width reduction capacity of 4.5 ml11 for the material to be rolled with a thickness of 3 mm supplied from the payoff reel 6. Therefore, the vertical roll 9.9 of A total width reduction of 9 mm, which is more than twice the plate thickness, is ensured.The dog bone 1a thus formed results in two castings in the final product, as shown in Figure 3. The edge drop (E) of the rolled material 1 is kept small.

As mentioned above, the thinner the plate is, the more likely it is to buckle rapidly, making it impossible to substantially reduce the width. The width of the material to be rolled 1 is reduced by the width reduction device 8, and in the case of tandem cold rolling, the material to be rolled 1 is reduced in width by the width reduction device 8 by the initial second pass. This makes it possible to reduce the workpiece, citro, and pu(E) of the rolled material 1.

Further, in the above embodiment, tension is applied to the rolled material 1 by the tension ply roll 7 on the entry side of the horizontal rolling mill 5, but when a width reduction device 8 is provided between the rolling mill stands, the rolling mill speed may be changed. Tension may be applied to the rolled material l by controlling.

Furthermore, only one set of vertical rolls 9 may be selectively used depending on the size of the edge drop (E) to be used as the -1 mark, and the present invention is not limited to the above embodiment.

(Effects of the Invention) According to the present invention, tension is applied to the material to be rolled to suppress the occurrence of buckling, and the material to be rolled is restrained by the restraint mechanism.
Since the width reduction of the material to be rolled is performed multiple times using a large number of vertical rolls, large tongue pawns can be formed at the edges of the material to be rolled during the rolling process. A product that effectively suppresses the occurrence of edge drops can be obtained. Moreover, since the total width reduction amount was more than twice the thickness of the material to be rolled, the third
As shown in the figure, the edge drop can be effectively reduced. Therefore, the thickness accuracy of the product can be improved, and the yield during rolling can be improved.

[Brief explanation of drawings]

1 to 3 show embodiments of the invention. Fig. 1 is a schematic explanatory diagram of a cold rolling machine for thin plates, Fig. 2 is a sectional view taken along the line II-II in Fig. 1, and Fig. 3 is a graph showing the relationship between width reduction j sand and edge drop. Figure 4 or 1
0 is a conventional example, FIG. 4 is a perspective view of the rolled material, FIG. 5 is a sectional view of the rolled material, FIG. 6 is a partially enlarged sectional view of FIG. 4,
FIGS. 7 to 10 are graphs showing experimental results in the conventional example, respectively. lag material to be rolled, 5--water rolling mill, 7--tension pry roll (tension adding device), 8--width rolling device, 9--vertical roll, 11--restraint mechanism. Engineering 1. IP Ne 100 vs. 1-/Le-<c (, t-) 工-rat main γγa sentence Ya branch @f=e4-6 piece-Q■ Ya6a, X back, 4\・,8■ width Hōsenki (γ.)

Claims (1)

[Claims] 1. During the rolling process of the material to be rolled, the material to be rolled is subjected to a total width reduction amount of at least twice the thickness of the material from the width direction, and a dog is applied to the edge portion of the material to be rolled. A method for cold rolling a thin plate, comprising forming bones and then horizontally rolling the material to be rolled. 2. In a cold rolling machine for thin plates, which is equipped with a plurality of horizontal rolling mills and allows the material to be rolled to pass through them one after another,
A tension applying device is provided to apply tension to the material to be rolled between the horizontal rolling mills, and a plurality of restraint mechanisms are provided along the rolling direction to sandwich the material to be rolled in this area from above and below. A cold rolling machine for thin plates, characterized in that vertical rolls are provided for rolling down both sides of a rolled material.