JPS6116525B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a lever rolling method with good width accuracy, and in particular, a method for rough rolling a steel slab using a row of rolling mills with horizontal rolls sandwiched between them and vertical rolls arranged on both sides. It is related to.

In recent years, as rolling mill rows for rough rolling slabs into plate shapes, the roll arrangement (vertical roll V ₁ -horizontal roll H- The use of rolling mill rows with roll V ₂ ) is increasing.

The rolling order for such a roll arrangement is shown in Figure 1a.
Following V ₁ -H-V ₂ in , V ₂ -H-V ₁ is performed as shown in b, and this is repeated to perform reverse rolling, but at this time, the vertical roll on the downstream side is In reality, there is generally an empty pass due to the danger of bumps caused by bending the board, and only the equipment on the entry side always functions as a vertical roll.

The problem with width reduction in such reverse rolling is, as shown in Figure 2a, the slab width B0 before vertical roll rolling, and the slab width B after vertical roll rolling.
1. If the width after horizontal roll rolling is B1', then B1
A large width change called width return occurs between B1' and B1', and the entrance side width cannot be accurately grasped when the next vertical roll is rolled down.

In other words, B1 can be calculated using the generally known gauge meter formula, but in that case, the cross section of the slab is
As shown in FIG. 2b, the width B1' after horizontal roll reduction is significantly different from B1 due to local deformation called dog bone.

This width return is affected by many factors such as material size, temperature distribution, roll conditions, etc., and cannot be accurately determined with current knowledge.The value is not determined even in the longitudinal direction of the material, and the width is not linear as shown in the figure. .

In order to control the strip width under such conditions, it goes without saying that it is desirable to accurately detect the strip width after rolling and give a rolling reduction amount instruction based on this detected value for each successive rolling pass. , no suitable method for actually measuring the width under such conditions during rolling has been developed so far.

The conventional method for measuring board width is to use a dedicated width measuring device such as an optical type, but this method generally requires expensive measuring devices, requires a large installation space, is difficult to maintain, and requires equipment. Due to constraints, in the case of a hot rolling mill with poor surroundings, it is necessary to install it in a location far from the rolling mill, and in particular, in a reverse rolling mill, it is necessary to install it in a location far away from the rolling mill. It is difficult to obtain width information over the entire length of the material.

The present invention enables reverse rolling with high width accuracy by adopting a width measurement method that is completely different from the conventional method described above. We focused on the fact that the vertical rolls on the downstream side are always idle when performing reverse rolling using the arranged rolling mill rows.
After rolling by the vertical rolls and horizontal rolls on the upstream side in the rolling direction, the downstream vertical rolls are made to follow the width of the material to be rolled under a predetermined light rolling condition, and the width of the material to be rolled is determined based on the amount of movement of the vertical rolls. Measure the width profile of
This reverse rolling method is characterized in that the width profile value is used to control the roll opening degree of upstream vertical roll rolling in subsequent reverse rolling.

A major feature of the present invention is that the vertical roll on the downstream side in the rolling direction is used to measure the width profile of the material to be rolled. The light rolling state at this time is a rolling state that does not cause plastic deformation in the rolled material and is sufficient to follow changes in the width of the rolled material, and its strength depends on the material and temperature of the rolled material. etc., and set it.

In other words, the rolling device (vertical roll on the downstream side in the rolling direction) is moved to follow the width profile of the material to be rolled, i.e., the rolling load is a constant small value (the above-mentioned light rolling). By making the vertical roll follow the width of the material to be rolled, the width profile is measured as the amount of movement of the vertical roll at that time.

According to this width profile measurement method, the amount of downward movement can be easily measured using various position detectors. In addition, since measurements are performed under light pressure,
This does not change the width of the object to be measured (rolled material).

FIG. 4 conceptually shows the position control mode of width profile measurement in the present invention, and FIG. 5 conceptually shows the constant pressure control mode.

Vertical rolls V ₁ and V ₂ are arranged on both sides of a horizontal roll stand H, and the slab S is first rolled by the vertical roll V ₁ and then by the horizontal roll H as shown in FIG. 1A. At this time, the downstream vertical roll V ₂ is used only for width profile measurement. During the subsequent reverse rolling shown in FIG. 1b, rolling is performed in the order of V ₂ →H, and V ₁ is used only for measurement.

Normally, after performing n passes of Figure 1 a and b,
The reverse rolling is completed by carrying out the process shown in FIG. 1c.

In the position control mode in FIG.
1, Rolling load detector 12, Roll gap detector 1
3. Consists of vertical rolls V ₁ and V ₂ .

In the constant pressure control mode in FIG.
It is composed of three vertical rolls V ₁ and V ₂ and a width profile measurement signal P is obtained.

FIG. 3 shows a block diagram of a configuration for carrying out the reverse rolling method of the present invention.

1 and 2 in the figure are width reduction control devices that incorporate roll gap detectors and rolling load detectors for the vertical rolls V ₁ and V ₂ , and the one located on the downstream side in the rolling direction is used for width measurement. The constant pressure control mode is switched to the constant pressure control mode as shown in FIG. At this time, the built-in roll gap detector continuously detects the roll movement amount of V ₂ (or V ₁ ) located on the downstream side as a width profile, and the detected value is immediately sent to the computer 3 for the next width control. Used for model calculations. Further, it is optional to immediately use this detected value as a feedback signal to control the width of the vertical roll during rolling, thereby increasing the responsiveness of the width control.

On the other hand, in the next reverse rolling, the width reduction control device 2 (or 1) located on the upstream side in the rolling direction
In order to provide width control, the vertical roll V ₂ (or Controls the roll opening degree of _V1 ) and performs adaptive correction of width control and reduction setting. By repeating this, reverse rolling with high width accuracy is performed for a predetermined number of passes.

According to the present invention, the width profile of the material to be rolled is detected by applying light pressure to the vertical roll on the downstream side in the rolling direction and detecting the amount of movement thereof, and using this detected value. High precision width control lever rolling is possible.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of width profile measurement in the present invention, Fig. 2a is an explanatory diagram of width return phenomenon in V-H lever rolling, Fig. 2b is a cross-sectional view,
The figure is a block diagram of the reverse rolling method of the present invention, FIG. 4 is a position control mode applied to the present invention, and FIG. 5 is a constant pressure control mode. V ₁ , V ₂ ; Vertical rolling mill, H; Reversing type horizontal rolling mill, S; Material to be rolled, 3; Width control calculator, 1,
2; width reduction control device (including a detection end for rolling load and roll gap); 10; control device; 11; reduction drive device.

Claims (1)

[Claims] 1. When performing reverse rolling using a row of rolling mills with horizontal rolls sandwiched between them and vertical rolls placed on both sides,
After rolling by the upstream vertical rolls and horizontal rolls, the downstream vertical rolls are made to follow the width of the material to be rolled under a predetermined light rolling condition, and the width of the material to be rolled is determined based on the amount of movement of the vertical rolls. A reverse rolling method characterized in that a width profile is measured and the width profile value is used to control the roll opening degree of the upstream vertical roll rolling of subsequent reverse rolling.