JP3224088B2 - Send line adjustment method for Sendzimir 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 pass line adjusting method for a Sendzimir mill, and more particularly, to a lower or upper pressing device and a side pressing device so that a pass line is always constant regardless of the diameter of a work roll or an intermediate roll. The present invention relates to a pass line adjusting method for a Sendzimir mill that can determine a combination of eccentric angles of a device.

[0002]

2. Description of the Related Art When rolling a material having high deformation resistance, such as a stainless steel plate, a multistage type, for example, a 20-stage Sendzimir mill is used. This Sendzimir mill is shown in FIG.
The upper and lower work rolls 12 for rolling the strip 10, pressing the work rolls 12, for example, two first upper and lower intermediate rolls 14, and pressing the first intermediate roll 14, for example, A configuration including three second intermediate rolls 16 and four upper and lower backing bearings 18 that press the second intermediate roll 16 in a state where they can be eccentric about each axis A to H, for example. Have been.

As shown in FIG. 2, the backing bearing 18 includes, for example, a plurality of eccentric saddles 20 divided in a strip width direction. The roll is rolled down and released. At this time, the B axis of the backing bearing 18 and the C
Axis, F-axis and G-axis forming the lower screw-down device 26, D-axis and E-axis forming the front (right side in the figure) side screw-down device 30,
A that constitutes the rear (left side in the figure) side pressure reduction device 32
The axis and the H axis are operated in conjunction with each other by a rack and pinion mechanism (not shown) or the like.

As described above, the 20-stage Sendzimir mill includes three lowering devices, which are roughly divided into a lower pressing device 26, side pressing devices 30, 32, and an upper pressing device 22. Of these, the lower pressure device 26 and the side pressure devices 30, 32
Is mainly used to determine the pass line, and the rolling pressure is given by controlling the upper pressing device 22.

However, since these reduction devices are mechanisms that rotate the eccentric saddle 20 by operating the reduction cylinders 24 and 28 or the reduction screw, the relationship between the reduction cylinder or the reduction screw and the roll reduction amount is linear. Not. FIG. 3 shows an example of the relationship between the rotational angles of the eccentric saddles of the side drafting devices 30 and 32 (hereinafter, referred to as side drafting eccentric angles) and the radial eccentric amounts (corresponding to the drafting amounts) of the rolls. FIG. 4 shows an example of the relationship between the rotational angle of the saddle (hereinafter, referred to as the lower rolling eccentric angle) and the radial eccentricity of the roll (corresponding to the rolling reduction).
Shown in

The only device capable of controlling the position during rolling is the upper pressing device 22.

Therefore, in general, automatic thickness control (AGC)
In consideration of the controllability of the thickness of the upper and lower cylinders, the lower and lower pressing devices 26 and 3 are set so that the upper and lower pressing cylinder positions can be set within a range where the relationship between the upper and lower pressing cylinders 24 and the roll position maintains linearity.
Rolling is performed by setting 0 and 32 appropriately. However, when the side drafting devices 30, 32 and the drafting device 26 also use the end of the operable range, the geometric relationship of the roll arrangement,
Rolling may not be possible due to the problem of interference with the guide in the mill, so that when the conditions of these rolling devices are changed, visual confirmation is required.

In particular, when the pass line is determined, two devices, ie, a side roll down eccentricity and a lower roll down eccentricity, are provided as means for controlling the work roll position. Since a means that cannot express the relationship linearly is used, it is common to determine the eccentric angle appropriately while visually confirming the position of each roll so that the pass line does not rise or fall extremely.

On the other hand, if the calculation time is not spared, numerical calculation is performed from each roll diameter, side reduction eccentric angle, and lower reduction eccentric angle using a geometric relationship as shown in FIG. It is also possible to determine the relationship between the reduction eccentric angle and the lower reduction eccentric angle. In FIG. 5, 16D is a second intermediate drive roll, and 16A is a second intermediate idle roll.

[0010]

However, the method of appropriately determining the pass line based on visual confirmation and experience as described above requires not only a long setup time at the time of setup, but also a problem that the top and bottom of the pass line are However, there is a problem that the shape is not stabilized because the vertical symmetry of the rolling is broken, and this is a main cause of shape defects such as warpage.

On the other hand, as in the latter case, the method of performing a strict numerical calculation based on the geometric relationship of each roll has a problem that it is not practical to use it online even with the current calculation function. Had.

The present invention has been made in order to solve the above-mentioned conventional problems. In a Sendzimir mill, the eccentricity angle of the side pressure reduction and the eccentricity angle of the side roll so that the pass line is always constant regardless of the diameter of the work roll and the intermediate roll. An object of the present invention is to make it possible to determine a lower rolling eccentric angle within a realistic time.

[0013]

SUMMARY OF THE INVENTION The present invention comprises a work roll, at least one intermediate roll for pressing the work roll, and a backing bearing for pressing the intermediate roll in an eccentric state. Mainly, an eccentric angle of a lower or upper pressing device for vertically lowering the lower or upper backing bearing of the work roll, and an eccentric angle of a side pressing device for substantially lowering the front and rear backing bearings of the work roll in the horizontal direction. In the pass line adjustment method of the Sendzimir mill where the pass line is determined by the core angle, from the geometric relationship of each roll, the lower or upper pressing device and the side pressing device are set to the pass line, with the limit of movement of the intermediate roll as a boundary condition. The regularity of the effect is calculated and modeled, and the model formula is used to calculate the bias between the lower or upper drafting device and the side drafting device. So as to determine the combination of the corner,
This has solved the above-mentioned problem.

In addition, as the above model equation, the following equation, which expresses the relationship between the eccentric angle x of the lower or upper pressing device and the eccentric angle y of the side pressing device by a hyperbola, is given by the following formula: ｛(x−x0) cos α + (y− y0) sin α｝ 2 / a2-｛(y-y0) cos α + (x-x0) sin α｝ 2 / b2 = 1 (1) (where a, b, and α are intermediate rolls and work rolls) (X0, y0 are also constants) determined by the diameter S and the distance S between the pass line and the center of the mill housing .

[0015]

Embodiments of the present invention will be described below in detail with reference to the drawings.

In practicing the present invention, first, FIG.
The pass line was calculated exactly using a 1/4 model of Sendzimir mill as shown in FIG. The eccentric operation of the side screw down device and the lower screw down device was simulated by changing the values of the diameter Da of the H axis and the diameter Db of the G axis. Until the pass line reaches the target value, iterative calculations were performed using geometric relationships and boundary conditions of contact and non-contact.As a result, the calculation accuracy was as good as ± 0.1 mm in actual measurement. However, the calculation time per condition is about 1 unit using a personal computer.
It took about 5 minutes, which proved to be impractical for the preset calculation.

From the rigorous calculation results, it can be seen that the relationship between the downward draft eccentric angle x and the side draft eccentric angle y for making the pass line constant can be approximated by a hyperbola. A formula was devised.

FIG. 6 shows an example of the relationship between the downward draft eccentric angle x and the side draft eccentric angle y for the pass line to be constant when the pass line target = 0 mm. The plot points in FIG. 6 are the solutions by the exact calculation, and the solid lines are the solutions by the simple calculation using equation (1). As the boundary condition in the simple calculation, the check by the first intermediate roll closest approach condition and the second intermediate roll and spray header (not shown) closest approach condition were sufficient. As is clear from FIG. 6, the result of simple calculation by the model formula (1) accurately represents the result of a strict solution by numerical calculation from a geometric relationship. The calculation accuracy by simple calculation is as good as ± 0.3 mm in actual machine measurement,
The calculation time per condition was about 15 seconds when using a personal computer, and it was confirmed that the method was sufficiently applicable to online preset calculation.

Therefore, if a model formula such as the formula (1) is used, a side pressure reduction device and a lower pressure reduction device for keeping the pass line constant in consideration of the upper work roll diameter and the thickness of the material to be rolled. The combination of the eccentric angles can be uniquely determined in a short time.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The diameter of the second intermediate drive roll 16D is set to 17
1.93 mm, the diameter of the second intermediate idle roll 16A is 1
76.16 mm, the diameter of the first intermediate roll 14 is 102.4
With 1 mm, comparison was made between two levels of the work roll 12 having a diameter of 50.3 mm and 49.0 mm.

In both cases, since the roll diameters other than the work rolls are the same, the work roll diameter φmax that can be loaded when fully released and the work roll diameter φ that can be loaded when fully reduced.
min is the same, φmax = 52.0 mm, φmin
= 45.0 mm. This is due to the geometric relationship
It can be calculated instantly without using numerical calculations.

Next, assuming that the diameter of the work roll is φ0, and the distance between the pass line and the center of the mill housing (the height of the deflor) is S, the following equation (2) is calculated: φ0 = 50.3 m
When m = 0 and S = 0, φ1 = 49.3 mm, φ0 = 49 m
When m = 0 and S = 0, φ1 = 48.0 mm.

Φ1 = {7 / (φmax−φmin)} (φ0−S) + [44− {7φmin / (φmax−φmin)}] (2)

Here, if the constants a, b and α in the equation (1) are determined as in the following equations (3) to (5), φ0 = 50.3 m
When m, a = 2.908, b = 4.888, α = 5
When 1.55, φ0 = 49.0 mm, a = 0.88,
b = 4.68 and α = 47.81.

A = 1.56φ1 −74.0 (3) b = 0.16φ1 −3.0 (4) α = 1.25 (φ1-47.5) ² +47.5 (5)

By substituting these constants into equation (1), x0 =
FIG. 7 (φ1 = 5) shows the relationship between the downward draft eccentric angle x and the side draft eccentric angle y with y0 = π / 2 (rad).
0.3 mm) and FIG. 8 (when φ1 = 49.0 mm).

When the diameter of the work roll is changed in this way, if the lower rolling eccentric angle x and the side rolling eccentric angle y satisfying the relationship shown in FIGS. Can be matched.

In the above embodiment, when the pass line and the center of the mill housing coincide with each other, φ1, a,
The equations for obtaining b and α have been described. However, if it is desired to offset the pass line and the center of the mill housing, a number other than 0 may be substituted for S.

In the above description, the pass line is determined based on the lower draft eccentric angle and the side draft eccentric angle. However, the present invention is not limited to this. When the pass line is determined by the angle and the side reduction eccentric angle, and the rolling pressure is given by the lower reduction eccentric angle,
It is clear that the same applies.

[0030]

According to the present invention, a constant pass line can always be set irrespective of the diameter of the work roll or the intermediate roll, so that the shape such as warpage can always be stabilized. or,
Since the visual confirmation at the time of determining the pass line is not required, the setting time can be reduced.

[Brief description of the drawings]

FIG. 1 is a side view showing a roll arrangement of a Sendzimir mill.

FIG. 2 is a front view showing the arrangement of rolls in the upper half.

FIG. 3 is a diagram showing an example of a relationship between a side reduction eccentric angle and an eccentric amount in a roll radial direction in a Sendzimir mill.

FIG. 4 is a diagram showing an example of the relationship between the eccentric angle of the lower pressure and the eccentric amount in the roll radial direction.

FIG. 5 is a diagram showing a Sendzimir mill 1/4 model used for exact calculation.

FIG. 6 is a diagram showing the principle of the present invention, showing an example of the relationship between the downward draft eccentric angle and the side draft eccentric angle for making the pass line constant.

FIG. 7 shows a work roll diameter 5 according to an embodiment of the present invention.
Diagram showing an example of the relationship between the downward draft eccentric angle and the side draft eccentric angle in the case of 0.3 mm

FIG. 8 is a diagram showing an example of the relationship between the downward draft eccentric angle and the side draft eccentric angle when the work roll diameter is 49.0 mm.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Strip 12 ... Work roll 14 ... 1st intermediate roll 16 ... 2nd intermediate roll 18 ... Backing bearing 20 ... Eccentric saddle 22 ... Upper reduction device 26 ... Lower reduction device 30, 32 ... Side reduction device

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-10-263638 (JP, A) JP-A-5-309402 (JP, A) JP-A-1-78612 (JP, A) JP-A-63-1988 123502 (JP, A) JP-A-63-11991 (JP, A) JP-A-63-80906 (JP, A) JP-A-62-148002 (JP, A) JP-A-48-79749 (JP, A) JP-A-57-175005 (JP, A) JP-A-7-256317 (JP, A) JP-A-4-26604 (JP, U) JP-A-1-15607 (JP, U) JP-A-59-20904 (JP, U) Japanese Utility Model Showa 57-165303 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B21B 37/00 B21B 13/14 B21B 31/20

Claims (2)

(57) [Claims] 1. A work roll comprising: a work roll; at least one intermediate roll for pressing the work roll; and a backing bearing for pressing the intermediate roll in an eccentric state. The pass line is determined by the eccentric angle of the lower or upper pressing device that vertically lowers the upper backing bearing and the eccentric angle of the side pressing device that approximately horizontally lowers the front and rear backing bearings of the work roll. In the Sendjimir mill pass line adjustment method, the regularity of the effect of the lower or upper rolling device and the side rolling device on the pass line is calculated from the geometric relationship of each roll, using the movable limit of the intermediate roll as a boundary condition. Using the model formula, a combination of the eccentric angles of the lower or upper drafting device and the side drafting device can be determined. Pass line adjusting method of Sendzimir mill characterized by. 2. The method according to claim 1, wherein the model formula is
The following equation expressing the relationship between the eccentric angle x of the lower or upper pressing device and the eccentric angle y of the side pressing device as a hyperbola: {(x−x0) cos α + (y−y0) sin α｝ 2 / a2 − ｛ (Y−y0) cos α + (x−x0) sin α｝ 2 / b2 = 1 (where a, b, and α are determined by the diameter of the intermediate roll or the work roll and the distance S between the pass line and the center of the mill housing. Characterized in that the determined constants, x0 and y0 are also constants).
Adjustment method.