JP2999075B2 - Roll leveling method for cross roll mill - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a roll leveling method for a cross roll mill in which upper and lower work rolls cross each other.

[0002]

2. Description of the Related Art In roll leveling of a cross roll rolling mill, a method similar to that of an ordinary four-high rolling mill in which a work roll is not crossed is used.

That is, as shown in FIGS. 4 and 5, immediately after the upper and lower work rolls 1 and 2 are rearranged, the lower work roll 2 supported by the lower backup roll and the upper work roll 1 are once brought into contact with each other. The upper backup roll 3 is rolled by the rolling device to a rolling force P _{W of} about 500 to
And reduction in P _D, rolling force difference Pdf = P _W -P _D between the working side WS and drive side DS at that time so that zero, both the reduction rate X _W, adjusting the X _D.

Thereafter, when the upper and lower work rolls 1 and 2 are crossed at a required cross angle θ, as shown in FIG.
The roll axis direction center C and cross point C ₀ matches, to form a working side roll gap h _W and a drive-side roll gap h _D, the h _W = h _D.

In this way, the work-side roll gap h
By equal _W and drive-side roll gap h _D, it can be rolled to uniform thickness with left-right.

[0006]

However, in a rolling mill equipped with a work roll chock, when the number of times of use of the upper and lower work rolls 1 and 2 increases, the dimension between the axis of the work roll 1 and the side of the work roll chock (not shown) increases. When the accuracy is reduced and the upper and lower work rolls 1 and 2 are crossed at a cross angle θ, as shown in FIG.
₁ and the lower work roll axis O _2, the horizontal displacement perpendicular to the roll axis direction (hereinafter, referred to as the offset [delta]) are generated.

In this case, as in the example of FIG.
₀ moves from the center C in the roll axis direction to the drive side DS, and the working-side cross amount (moving amount) l _w and the working-side roll gap h
_W is larger than the driving-side weight Cross (amount of movement) l _D and drive-side roll gap h _D.

When the work side roll gap h _W and the drive side roll gap h _D become unequal, the rolled material to be rolled also has a sheet thickness difference between the work side WS and the drive side DS (hereinafter, referred to as a sheet wedge). ) Occurs.

[0009] This sheet wedge not only results in poor quality of the rolled material, but also induces bending of the sheet, so that the sheetability during rolling is reduced, and the rolled material meanders and deviates from the center of the rolling mill. , Normal rolling operation becomes impossible.

[0010]

According to a roll leveling method of the present invention, after setting a work roll in a housing, an upper work roll and a lower work roll are set to a plurality of cross angles, and each of the cross angles is set. The difference between the working-side rolling reduction and the driving-side rolling reduction at which the difference between the working-side rolling reduction and the driving-side rolling reduction becomes zero is measured. The offset amount in the horizontal direction perpendicular to the roll axis direction with respect to the lower work roll is calculated, and the difference in the reduction amount at an arbitrary cross angle is calculated from the offset amount according to the equation (2). Leveling the work roll at a corner. δ = (Dω / 2L) · {(Hdf ₂ −Hdf ₁ ) / (θ ₂ −θ ₁ )} (1) Hdf = (2L / Dω) · δ · θ + Hdf ₀ ... (2) where, Hdf: difference between the working-side rolling reduction and the driving-side rolling reduction (leveling amount) L: distance between the working-side rolling reduction and the driving-side rolling reduction θ: rolling of upper and lower work rolls Intermediate cross angle δ: Offset amount in the horizontal direction orthogonal to the roll axis direction of the upper and lower work rolls Dω: Work roll diameter Subscript: Each value at each cross angle θ

[0011]

After setting the work rolls by changing the rolls, set the cross angle to, for example, 0 ° and / or 0.5 °, and measure the difference in the amount of reduction in the reduction of the reduction force between the working side and the drive side. Further, the required cross angle is set to, for example, 1 °, and the reduction amount is set so that the reduction force difference becomes zero, and the leveling amount is measured.

Based on these two measured leveling amounts, the offset amounts of the upper and lower work rolls are calculated by an equation. Since the offset amount in this work roll is always constant, when the cross angle is changed for changing the rolling conditions, the leveling amount corresponding to the cross angle is calculated back from the offset amount, and the roll leveling is performed by the leveling amount. to correct.

[0013]

An embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a front view showing the concept of a cross roll rolling mill and a roll leveling method, FIG. 2 is a diagram showing a roll leveling position and a roll leveling correction position, and FIG.
FIG. 3 is a diagram showing a reduction amount difference for leveling correction with respect to an arbitrary roll cross angle.

As shown in FIG. 1, after the upper and lower work rolls 1 and 2 are rearranged, the upper and lower work rolls 1 and 2 are supported by the lower backup roll 4 and brought into contact with each other, as in the prior art. load P _W, so that the difference of P _D becomes zero, adjust the working side pressure under volume X _W and the driving side pressure under volume X _D, then, for example, above in the cross angle theta = 1 °, the lower two workpieces Roll 1,2
Cross. At this time, the upper and lower work rolls 1, 2
If the offset is generated between the work-side roll gap h _W becomes larger than the drive-side roll gap h _D (see FIG. 7).

This roll gap difference hdf = (h _W -h
_D ) can be represented by the following equation. hdf = (2Lω · θ · δ) / Dω (1) where Lω: Work roll barrel length θ: Cross angle δ: Upper and lower Offset amount between work rolls Dω: Work roll diameter

At this time, the working side WS and the driving side DS
Leveling amount Hdf = (X _W-X_D) Is
Become. Hdf = (L / Lω) · hdf = (2 · L · θ · δ) / Dω (2) where L is the distance between the work-side pressure reduction point and the drive-side pressure reduction point.

That is, the offset amount δ is generated as a pair difference between the pair of work rolls 1 and 2 and is always constant when the rearrangement of the upper and lower work rolls 1 and 2 is completed. Since L and Dω are also constant, the above-described roll gap difference hdf and leveling amount Hdf will change proportionally depending on the cross angle θ.

Therefore, as shown in FIG. 2, at the cross θ = 0 ° and θ = 1 °, the respective leveling amounts Hdf at which the respective rolling force differences Pdf become zero, that is, the leveling amounts A and B are obtained.

FIG. 3 shows these results as a relationship between the cross angle θ and the leveling amount Hdf. This figure shows the leveling amount at an arbitrary cross angle.
It can be expressed by the following equation. Hdf = (2Lδ / Dω) · θ + Hdf ₀ (3)

The slope 2Lδ / Dω in this equation is obtained by the following equation as the slope of a straight line connecting the two points A and B. 2Lδ / Dω = ΔHdf / Δθ = (Hdf 2 -Hdf 1) / (θ 2 -θ 1) ··· (4)

The offset δ of the upper and lower work rolls can be expressed by the following equation. δ = (Dω / 2L) ｛{(Hdf ₂ −Hdf ₁ ) / (θ ₂ −θ ₁ )} (5)

As described above, since the offset amount δ is always constant for the pair of upper and lower work rolls, the leveling amount at an arbitrary cross angle can be calculated by the following equation. Hdf = {(Hdf ₂ −Hdf ₁ ) / (θ ₂ −θ ₁ )} · θ + Hdf ₀ (6) where Hdf ₀ : the leveling amount when θ = C

As described above, the upper work roll 1 and the lower work roll 2 are crossed at a required cross angle θ, linearly corrected by the leveling amount Hdf obtained above, and the work side roll gap h _W and the drive side roll gap as the difference between h _D becomes zero, roll leveling.

When the cross angle θ is changed to change the rolling specifications such as the thickness, width, and material of the rolled material or to control the sheet wedge during rolling, the cross angle θ is changed according to the changed cross angle θ. Is adjusted to the leveling amount Hdf, and roll leveling is performed.

[0025]

According to the present invention, at a plurality of cross angles,
By measuring the leveling amount at which each rolling force difference becomes zero, calculating the offset amount from this leveling amount, calculating the leveling amount at an arbitrary cross angle from this offset amount and performing roll leveling, when setting the work roll. In addition, the offset amount can be easily calculated, and even if any cross angle is adopted or the cross angle is changed, the roll leveling can be easily and appropriately performed.

Therefore, it is possible to roll a strip without a plate wedge, thereby improving the quality and yield, and improving the rollability, so that there is no misroll and the productivity is improved. Further, since the roll leveling operation can be automated, and the leveling intervention operation by the operator becomes unnecessary, the labor can be saved.

[Brief description of the drawings]

FIG. 1 is a front view showing a concept of a cross roll rolling mill and a roll leveling method according to an embodiment of the present invention.

FIG. 2 is a diagram showing a relationship between a rolling force difference and an amount of leveling at an arbitrary cross angle.

FIG. 3 is a diagram showing a leveling amount for leveling correction.

FIG. 4 is an explanatory diagram showing a conventional roll leveling method.

FIG. 5 is a diagram showing a leveling position in a conventional roll leveling method.

FIG. 6 is an explanatory diagram showing the relationship between the state of intersection between the upper and lower work rolls and the roll gap amount when there is no offset between the upper and lower work rolls.

FIG. 7 is an explanatory diagram showing a relationship between an intersecting state of upper and lower work rolls and a roll gap amount when an offset occurs.

[Explanation of symbols]

1 upper work roll 2 lower work roll A leveling position B leveling correction position DS drive side WS work side h _D drive side roll gap h _W work side roll gap P _D drive side reduction force P _W work side reduction force X _D drive side reduction The amount X _W working side pressure under amount θ cross angle δ offset Hdf leveling amount

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-5-38504 (JP, A) JP-A-5-269513 (JP, A) JP-A-5-277529 (JP, A) 42561 (JP, B2) (58) Field surveyed (Int. Cl. ⁷ , DB name) B21B 37/58 B21B 31/16 B21B 13/14

Claims (1)

(57) [Claims] After setting a work roll in a housing, an upper work roll and a lower work roll are set at a plurality of cross angles, and the difference between the working side reduction force and the drive side reduction force at each of the cross angles. The difference between the work-side reduction amount and the drive-side reduction amount at which is zero is measured, and the horizontal direction perpendicular to the roll axis direction of the upper work roll and the lower work roll is obtained from the respective reduction amounts according to the equation (1). Is calculated from the offset amount according to the equation (2), and the work roll at an arbitrary cross angle is leveled based on the difference between the reduction amounts. Roll leveling method for cross roll mill. δ = (Dω / 2L) · {(Hdf ₂ −Hdf ₁ ) / (θ ₂ −θ ₁ )} (1) Hdf = (2L / Dω) · δ · θ + Hdf ₀ ... (2) where, Hdf: difference between the working-side rolling reduction and the driving-side rolling reduction (leveling amount) L: distance between the working-side rolling reduction and the driving-side rolling reduction θ: rolling of upper and lower work rolls Medium cross angle δ: Offset amount in the horizontal direction perpendicular to the roll axis direction of the upper and lower work rolls Dω: Work roll diameter Subscript: Each value at each cross angle θ