JPH05169116A - Rolling method - Google Patents

Abstract

PURPOSE:To roll a stock to be rolled without meandering the stock with plural rolling mills having a pair of upper and lower working rolls supported freely reciprocatively in the direction of a rotary axis. CONSTITUTION:From the 4th rolling mill (m) of a 4th number by counting from the left side of the inlet side of strip (p) of the rolling mill line composed of 7 rolling mills (m) having respectively a pair of upper and lower working rolls 1, 2 and backup rolls 3, 4 up to the 7th rolling mill (m) of outlet side is defined as the rolling mills (m) having the working rolls 1, 2 reciprocating in the direction of a rotary axis, since the roll gaps between both work rolls 1, 2 can be made symmetrical by respectively measuring profiles of working rolls 1, 2 of the 4 rolling mills (m) and grinding the working roll having small profile deformed amount so as to be the same profile with the working roll having large profile deformed amount, the draft is made symmetrical to the center even if these are moved in the direction of the rotary axis and the rolled stock is not meandered at the time of the rolling.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rolling method and, more particularly, to a rolling method for preventing the meandering of a material to be rolled during rolling so that a work roll can be used for a long time.

[0002]

2. Description of the Related Art In recent years, in the field of strip rolling, in order to control the strip thickness distribution in the width direction of a strip to be rolled, a pair of upper and lower parts are supported so as to be reciprocally movable in the rotational axis direction. A rolling mill having a work roll has been widely used. However, such a rolling mill has a drawback that the rolled sheet material is likely to meander during rolling, as compared with a conventional rolling mill having a work roll that cannot move in the direction of the rotation axis.

That is, in the case of a conventional rolling mill having immovable work rolls, the upper work roll 1 and the lower work roll 1 are worn by abrasion as shown in FIG. Even if the profiles of the two work rolls in the direction of the rotation axis are different, the profile of the gap between the work rolls 1 and 2 is axially symmetrical with respect to the center of the work rolls 1 and 2 in the direction of the rotation axis. Therefore, the left-side plate thickness distribution t _l of the rolled plate material p and the right-side plate thickness distribution _tr are symmetrical, that is, the left and right reduction ratios of the rolled plate material p are symmetrical, and the rolled plate material p meanders. Never.

On the other hand, in a rolling mill having a pair of upper and lower work rolls that can move in the direction of the rotation axis, as shown in FIG. 4 which is a schematic configuration explanatory view showing the main part, the upper work is caused by the abrasion of the roll. Roll 1 and lower work roll 2
If the upper work roll 1 and the lower work roll 2 are moved in opposite directions when the profile along the direction of the rotation axis of the is vertically asymmetrical, the profile of the gap between the upper work roll 1 and the lower work roll 1 Is asymmetrical, the plate thickness distribution of the rolled plate p is asymmetrical,
Since there is a difference in the rolling reduction, the rolled plate material p will meander.

When a rolling trouble called "narrowing" occurs due to the meandering of the rolled plate material p, the work rolls are damaged, so that the work rolls need to be replaced and the rolling work efficiency decreases. It was happening.

By the way, FIG. 5 shows "narrowing" to a rolled sheet material.
The upper and lower work rolls of the rolling mill that generated the above are removed from the line, and their profiles are measured using a contact roll profile meter attached to the roll grinder.

According to the figure, the profiles of the upper and lower work rolls are substantially symmetrical and have similar shapes, but there is a difference of about 30 μm in radius at the center position of the work rolls in the direction of the rotation axis. There is.

That is, the strip rolling conditions in which "narrowing" has occurred are: strip width; 1200 mm work roll movement amount; 300 mm inlet side sheet thickness; 2.1 mm outlet side sheet thickness; 1.5 mm. The roll gap difference between the left and right ends in the width direction is about 25 in radius.
It is μm, and it can be seen that it was in a state in which it was extremely easy to meander in view of the plate thickness and the rolling reduction. What prevents the meandering of the rolled plate material due to such movement of the work roll is disclosed in, for example, Japanese Patent Laid-Open No. 63-76710.

This is because, when rolling a rolled sheet material, the profile calculation values of the upper and lower work rolls are corrected based on the sheet thickness of the rolled sheet material measured between rolling passes, and then the corrected work roll profile is used. Any one or more of the leveling, the movement amount of the work roll, and the bender force are controlled so that the plate thickness difference in the width direction of the rolled plate material does not occur in the next pass.

[0010]

Although the above method is useful as such, it still has problems to be solved as described below in view of its versatility and economy. That is, since the profile calculation values of the upper and lower work rolls are corrected based on the plate thickness of the rolled plate material that is actually measured between rolling passes, in order to apply it to tandem rolling, the plate on the exit side of each rolling mill must be individually adjusted. Profile total is needed.

Further, in addition to the need for a highly accurate model for correcting the profile calculation value of the work roll by using the measured plate thickness, the profile of the asymmetrical gap between the upper and lower work rolls is calculated. There is also a problem that the control software becomes complicated because a high-accuracy control model is required to compensate for control such as leveling.

Therefore, it is an object of the present invention to provide a rolling method in which the meandering prevention that occurs during rolling in a rolling operation can be applied to continuous rolling by a plurality of rolling mills and the work roll replacement interval can be extended. And

[0013]

The present invention has been made in view of the above circumstances, and the gist of the rolling method according to the present invention is to provide a pair of upper and lower members supported so as to be reciprocally movable in the rotational axis direction. In a rolling method for rolling a material to be rolled by a rolling mill having a work roll, a profile along each rotation axis direction of a pair of upper and lower work rolls is measured, and then a work roll with a small amount of profile deformation based on the measurement result. Is ground into the same shape as the profile of a work roll having a large amount of profile deformation.

[0014]

According to the rolling method of the present invention, the profiles of the pair of upper and lower work rolls along the direction of the rotation axis are measured, and then the work roll having the smaller profile deformation amount is measured based on the measurement result. Since it is ground to the same shape as the profile of many work rolls, the gap between both work rolls becomes symmetrical, so even if the work roll is moved in the direction of the rotation axis, the rolling reduction in the width direction of the rolled material is achieved. The distribution is symmetric with respect to the plate width center.

[0015]

EXAMPLES Examples of the present invention will be described below with reference to FIG. 1 which is a schematic configuration explanatory view of a rolling line which constitutes a row of hot rolling mills and FIG. 2 which is a schematic explanatory view of a profile measuring apparatus and a grinding apparatus. While explaining. As shown in FIG. 1, the rolling mill train is composed of seven rolling mills m each including a pair of upper and lower work rolls 1 and backup rolls 3 and 4. 4 counting from the left
From the 4th rolling mill to the 7th rolling mill on the final exit side
Each of the lower work rolls 1 and 2 (shown by hatching in the figure) is movable in the direction of the rotation axis.

In the hot rolling mill train having such a structure, work roll profile measurement and grinding can be performed in a state where the work rolls of the fourth to seventh rolling mills are incorporated in the rolling mill. .. Further, in the profile measuring device and the grinding device, as shown in FIG. 2, the profile detector 5 and the grinder 6 are arranged at equal intervals with the adjacent detector and grinder, respectively, and move in the direction of the rotation axis of the work roll. The structure is possible. The measurement result by each profile detector 5 is the profile calculator 7
Processed to obtain a profile of the entire upper and lower work roll lengths.

Further, the grinder control device 8 controls the operation of each grinder by calculating the grinding amount at each position in the rotational axis direction of the work roll having the smaller profile deformation amount based on the above calculation result. ..

The present invention was carried out by using such an apparatus for rolling for 3 cycles (1 cycle means from the work roll rearrangement of the entire rolling mill to the next rearrangement). That is, in the cycle in which the present invention is carried out, one cycle is composed of 50 strips, and every time one strip is rolled, the profile of the work rolls of the fourth to seventh rolling mills in the rotational axis direction is measured. , The difference between the profiles of the upper and lower rolls is 20 μm at the center of the rotation axis.
Grinding was performed when the above was reached. The target cycle was composed mainly of a thin material that is prone to meandering, but in any cycle, the material to be rolled could be rolled without troubles such as "narrowing" due to meandering.

Therefore, according to this embodiment, a high-accuracy model for correcting the profile calculation value of the work roll by using the actually measured plate thickness as in the prior art and the left-right asymmetry between the upper and lower work rolls 1 and 2 are used. It is not necessary to use a high-precision control model for compensating the gap profile of the above with control such as leveling, and by simply matching the upper work roll 1 with a small amount of profile deformation to the profile of the lower work roll 2 with a large amount of profile deformation, Work rolls 1 and 2
Can be used for a long time.

[0020]

As described in detail above, according to the rolling method of the present invention, since the roll gaps between the work rolls are symmetrical, even if the work rolls are moved in the rotational axis direction, Since the reduction ratio distribution in the width direction of the rolled material is symmetrical with respect to the center of the strip width, it is possible to prevent the material to be rolled from meandering, and it is possible to significantly improve the rolling work efficiency.

[Brief description of drawings]

FIG. 1 is a schematic configuration explanatory view of a rolling line that constitutes a hot rolling mill train according to an embodiment of the present invention.

FIG. 2 is a schematic explanatory view of a profile measuring device and a grinding device used in implementing the present invention.

FIG. 3 is a schematic configuration explanatory view showing a main part of a conventional rolling mill having a work roll that cannot move.

FIG. 4 is a schematic configuration explanatory view showing a main part of a conventional rolling mill having a pair of upper and lower work rolls that can move in a conventional rotation axis direction.

FIG. 5 is an explanatory view of a work roll profile of a rolling mill in which “narrowing” is generated in a rolled plate material.

[Explanation of symbols]

 m ... rolling mill p ... strip 1 ... upper work roll 2 ... lower work roll 3 ... upper backup roll 4 ... lower backup roll 5 ... profile detector 6 ... grinder 7 ... profile calculator 8 ... grinder controller

Claims (1)

[Claims] 1. A rolling method for rolling a material to be rolled by a rolling mill having a pair of upper and lower work rolls supported so as to be reciprocally movable in the direction of the rotation axis. A method for rolling, characterized in that a profile along a line is measured, and then a work roll having a small amount of profile deformation is ground into the same shape as a profile of a work roll having a large amount of profile deformation based on the measurement result.