JPH01154807A - Rolling mill - Google Patents

Abstract

PURPOSE:To roll a high quality thin sheet free from shape defects by installing a 2nd intermediate roll of a specific diameter having a roll bending function and a roll shift function in the axial direction between a work roll and an intermediate roll of a UC mill. CONSTITUTION:As for a six-high mill having work rolls 1, intermediate rolls 3, and backup rolls 4, the work rolls 1 are provided with a roll bending function and a diameter DW of the rolls 1 is made to be <1.5W; the intermediate rolls 3 are provided with a roll bending function and roll shift function in the axial direction and a diameter D1 of the rolls 3 is made to be >0.25W. Further, 2nd intermediate rolls 2 having a diameter of D12, a relationship such as DW<D12<D1, a roll bending function, and a roll shift function in the axial direction are installed between the rolls 1 and rolls 3. Hence, shape defects caused by thermal crowns are improved by combining respective functions of the rolls 1, 2, 3 to show higher order bending functions than a six-high mill.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention is effective in manufacturing thin hard materials and high quality products, and particularly relates to a cold rolling mill suitable for rolling wide materials.

[Conventional technology]

Regarding rolling of hard and thin materials, attempts have been made to use work rolls with as small a diameter as possible, since rolling is impossible with large diameter work rolls due to roll flattening. Sensimer mills have conventionally been used for this purpose, and in particular, only Sensimer mills have been used for rolling wide thin materials. This Sensimer mill has the following functions to control the shape of the strip: (1) AS to adjust the rolling position of the backing bearing;
-U mechanism.

(2) Direction - Although there is an adjustment in the axial direction of the intermediate roll, it is not possible to obtain a good product shape with these functions, so it is necessary to make a slight taper on the intermediate roll depending on the width and material of the rolled material. This is done using auxiliary means and experience, but the operation is complicated.

The ZH mill was devised to improve this function. This mill is equipped with support rolls on the exit side to prevent horizontal deflection of the small-diameter work rolls caused by driving the intermediate rolls, and an intermediate roll is installed between the work rolls and reinforcing rolls to control the shape. It has axial movement and bending functions. However, like the Sensimer mill, this ZH mill is not equipped with a work roll bender, so the work roll is bent greatly at the edge of the sheet, resulting in a large edge drop, as shown in FIG. Furthermore, as is obvious from a geometrical perspective, in order to secure a space for installing a support roll for preventing horizontal deflection of the work roll, the diameter of the intermediate roll is limited, making it impossible to use a large-diameter intermediate roll. For this reason, in a wide width mill, it is not possible to secure an intermediate roll diameter that has the roll bending effect necessary for shape control, and sufficient shape control cannot be achieved.

Meanwhile, U
The C-mill has the ability to correct complex elongation shapes that are a mixture of end elongation and mid-elongation.This makes it possible to correct shape defects caused by thermal crowns, which were previously said to be difficult to correct. became possible. however,
In the case of extremely small diameter work rolls, an intermediate roll is driven, and a support roll is attached as shown in Fig. 5 to prevent horizontal deflection of the work roll.

As a result, a thin product with a good shape, which could not be obtained with the Sensimer mill or the ZH mill, can be obtained.

[Problem that the invention seeks to solve]

The above-mentioned conventional technology has the following problems and needs to be improved.

A work roll with a small diameter and a long surface length is used as a rolling mill for hard wide materials, but because the work roll is small in diameter, it is impossible to drive the work roll, so it is necessary to use an intermediate roll or , it becomes a backup roll drive. As a result, the torque on the work roll is applied by the tangential force from the intermediate roll, and this tangential force causes horizontal deflection on the small diameter work roll and disturbs the plate shape. A support roller for the work roll is required.

As shown in Figure 5, UC mills with support rollers have a geometrical limit on the diameter of the intermediate roll in order to secure the space H between the upper and lower support rollers necessary for threading and operation. If it becomes impossible to ensure the roll diameter D+>0.25W and the intermediate roll diameter becomes 30 OrIn or less with a small diameter work roll as shown in Figure 6, the order of deflection of the work roll by the intermediate roll bender becomes 3rd order or higher, causing crown fluctuation of the base material. For disturbances approximated at the quadratic level,
As shown in Fig. 7, the correction is insufficient, resulting in large center and edge extensions. To compensate for this lack of correction ability, there is a method to give an initial crown to the work roll or to set the intermediate roll shift position to the minus side by a wide width from the sheet edge, but the intermediate roll shift is often performed during rolling. If the operation becomes complicated due to changes in position, the shape stability of the strip is reduced, and the intermediate roll shift position is set to the minus side from the strip edge, light may be caused by the intermediate roll shoulder on the surface of the work roll in the high surface pressure area. Since selective differences occur and are transferred to the strip surface, the frequency of roll replacement increases in the case of products with severe surface quality, reducing production efficiency.

In a wide mill with a small diameter work roll, the deflection order of the work roll itself is high order, and the change in the roll profile due to the thermal crown is also high order.

In an internal mill, as shown in Figure 8, the intermediate roll and backup roll are in contact even outside the board width, so the intermediate roll receives reaction force from the backup roll outside the board width, so the intermediate roll Since the effect of the roll bender is reduced and the work roll deflection order due to the intermediate roll bender with D+>0.25W is low, it does not have the ability to modify the shape to the B zone in FIG. 8. In addition, since the small diameter work roll bender has a high work roll deflection order, A in Fig. 5
It has the ability to modify the shape only for the zone, and has no effect on the B zone.

As a result, the ability to correct the shape of zone B in FIG. 8 is insufficient, and elongation remains in a portion of 1/6 to 1/8 of the board width, resulting in a defective shape. This tendency becomes more pronounced as the diameter of the work roll becomes smaller, as the width of the sheet becomes wider, and as the rolling speed increases and thermal crowns occur more frequently. In order to produce a shape correction effect on the B zone, the intermediate roll shift is applied to the board width,
When set to the negative side, even if the B zone is improved, the shape of the A zone deteriorates. Further, although it is possible to improve the B zone by performing zone control and spot cooling of the roll coolant, the response until the effect becomes effective is slow and it is not possible to respond immediately to changes in the shape of the slip.

The present invention deals with a reduction in shape control ability due to the inability to secure intermediate rolls with DI > 0.25W and DW < 0.15W in a wide-width, small-diameter work roll rolling mill with support rollers. The object of the present invention is to provide a rolling mill that improves shape defects caused by high-order thermal crowns that are difficult to correct in a 6H mill that is a combination of work rolls and intermediate rolls with a DI>0.25W.

[Means for solving problems]

The above purpose is to use a wide mill with small diameter work rolls for work rolls with a DW < 0.15W having a deflection order of the sixth order or higher and intermediate rolls with a DI>0.25W having a deflection order of the second order or less. A second intermediate roll with an intermediate deflection order and a roll diameter of 0.15W<DI2<0.25W is added at the top and bottom, and this second intermediate roll also has a roll bending function and a roll axis direction. This is achieved by adding a shift function.

[Effect]

The arrangement of the rolls of the six-high mill according to the present invention and the action of force on the rolls are shown in FIG.

The second intermediate roll in contact with the small diameter work roll has a diameter of DI2.
is 0.15W<DIz<0.25Wf7) t4, which is the diameter considering the work roll support roller mounting space.

The intermediate roll in contact with the backup roll typically has a diameter of DI>0.25W, similar to that of an internal UC mill.

The intermediate roll and the second intermediate roll have a bending function and shift in the axial direction and in opposite directions to match the width of the sheet.

The deflection orders of the work rolls resulting from this combination of rolls are 6th to 5th orders for the work rolls, about 2nd orders for the intermediate rolls, and 3rd to 5th orders for the second intermediate rolls.

Second-order disturbances such as base material crown variation, center elongation, and edge elongation are dealt with by an intermediate roll beder, and work roll intermediate rolls, With the combination of the first intermediate roll bender and the second intermediate roll bender, it is possible to make corrections as shown in FIG.

Unlike the long UC mill, the second intermediate roll does not contact the back roll because the contacting intermediate roll has shifted to the opposite side as shown in FIG.

For this reason, there is no reaction force from the back roll, and the bending effect of a higher order than the intermediate roll of the killing mill can be fully utilized, making it possible to modify the shape to the B zone in Figure 8. / Small diameter wide crotch UC with elongation remaining in the 6th to 1/8th section
He can compensate for Mill's runner-up position.

The shape correction of the plate end and the improvement of edge drop can be carried out using a work roll bender that provides a high order of deflection as shown in FIG.

As a result of this action, the small-diameter, wide-width corrugated mill with support rollers of the present invention can achieve low-level rolling with the shape correction ability of the bender alone, without having to shift the intermediate roll to the inside of the sheet width or adjusting the shift position during rolling. base metal crown variation, and
It can handle a wide range of disturbances, from rolling load fluctuations to disturbances caused by high-order thermal crowns.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1, 2, and 3.

The basics of this rolling mill are a work roll 1, a second intermediate roll 2,
Intermediate roll 3. and a reinforcing roll 4.

The work roll 1 is supported by the intermediate support rollers 13 and 14 via the support roller support lever 15 attached to the second intermediate roll metal check 7, and the work roll is supported by the tangential force received from the second intermediate roll 2. It has a structure that prevents horizontal deflection.

The support rollers 13 and 14 are supported by a support roller support block 16, a slider 17, and a positioning stopper 18 via a support roller support lever 15, and changes in the work roll diameter and support roller diameter are controlled by electrical control, etc. Adjust the moving wedge 19 with .

The work roll is equipped with a metal chock and is held in a second intermediate roll metal chock 7, and an increase/decrease bending cylinder 5 is built into the work roll chock for shape control.

The second intermediate roll 2 is not only movable in the axial direction by a shift device attached to a metal chock, but also bent by a bending cylinder 9.

The intermediate roll is built into a metal chock and has an axial displacement device and a bending device 10°11.12.

The work roll is replaced by the second intermediate roll 2. There is a method in which the intermediate support roller 13, the support roller 14, and the intermediate roll metal chock 7 are pulled out together and done offline, and a method in which only the work roll and metal chock are pulled out.

The intermediate roll 3 is replaced at the same time as the second intermediate roll 2, or independently.

Replacement of the reinforcing roll is the same as the conventional one.

Further, this mill can also have a structure like the tenth one, and the only difference is in the support roller 5 and the method of supporting the support roller, and the structure of the support roller can also be different.

〔Effect of the invention〕

According to the present invention, shape defects caused by high-order thermal crowns can be improved.

[Brief explanation of the drawing]

FIG. 1 is a roll arrangement diagram of an eight-tier mill according to an embodiment of the present invention.
Fig. 2 is a front view of an eight-high mill according to the present invention, Fig. 3 is a cross-sectional view of an eight-high mill according to the present invention, Fig. 4 is a comparison diagram of edge drops of a ZH mill and a UC mill, and Fig. 5 is a support roller. Figure 6 is a diagram showing the relationship between intermediate roll diameter and bender order, Figure 7 is a comparison diagram of corrections made against disturbances, Figure 8 is a side view of defective shape of a small diameter wide inner thigh mill, Figure 9
The figure shows a modification of the shape of a small-diameter wide six-stage mill, and Figure 10 shows an example of an eight-stage mill. 1... Work roll, 2... Second intermediate roll, 3...
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Claims (1)

[Claims] 1. D_W<0.15W with roll bending function
In a UC mill consisting of a work roll, an intermediate roll with D_I>0.25W and a backup roll having roll bending and axial shifting functions, there is a roll diameter of D_W<D_I_2<D_I between the work roll and the intermediate roll. have a relationship of
A rolling mill comprising a second intermediate roll having the roll bending function and the axial shifting function. 2. In claim 1, the axial shift of the intermediate roll is such that the roll and metal chock move simultaneously, or the metal chock is fixed and only the intermediate roll moves, or A rolling mill characterized by having a combination of these functions.