JPS60210307A - Rolling mill - Google Patents

Abstract

PURPOSE:To obtain a flat rolled-sheet free from composite stretches and to improve its yield by providing rolls acting in the horizontal direction, to the central part and both ends of a work roll and correcting both of the shape and herringbones of a rolling material. CONSTITUTION:A rolling mill is formed by arranging the 1st rolls 16, 17, which hold simultaneously the central parts of work rolls 1, 2 in the horizontal direction from the front and back along the running direction of a rolling material, and the 2nd and 3rd rolls 18-21. Pushing forces acting on both side-ends of the work rolls 1, 2, toward the front and back sides in the horizontal direction, are supported by the above-mentioned 2nd rolls 18, 19 and the 3rd rolls 20, 21. The deflections in the horizontal planes of work rolls are controlled by the mill mentioned above, and fine herringbone creases in the oblique directions and central and end stretches are corrected.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a plate rolling mill in which the deflection of work rolls in a horizontal plane can be controlled.

[Background of the invention]

In recent years, requirements for plate thickness accuracy of rolled products have become increasingly strict. With the development of automatic thickness controllers (AGC), we have reached a stage where we are almost satisfied with the accuracy of plate thickness in the longitudinal direction, but the accuracy of plate thickness in the width direction, that is, the shape and crown of the plate, is Further improvements are desired. Of course, roll benders have been developed for conventional four-high rolling mills, and similar effects have been obtained. A further improved model is equipped with at least a pair of intermediate rolls 3 and 4 that are movable in the axial direction as shown in FIG. A rolling mill of the type in which the shape of the rolled material 7 is controlled by a combination of benders 8 and 9 has been developed, and considerable effects have been obtained. However, these roll benders attempt to control the deflection of the work roll in the vertical plane, thereby controlling the thickness distribution in the width direction, and there is no control whatsoever for deflection in the horizontal plane. . On the other hand, in recent years, there has been a noticeable trend to reduce the diameter of work rolls, reduce rolling loads, and reduce the number of passes through strong rolling pressure in order to save energy and resources. has also started to attract attention. That is, if we consider the horizontal plane parallel to the material as shown in Figure 2, the following forces are acting on the work roll. Generally, when the diameter of the work roll 1 is reduced, the drive coupling is attached to wood vinegar, so the reinforcing roll 5 is driven as shown in FIG. 2. Therefore, the work roll receives a tangential force Fa as shown in FIG. 2 from the reinforcing roll. In addition, the tensions σb, σ on the entrance and exit sides that are applied to the material
If there is a difference in f, this amount will also be added as a horizontal force. These forces cause the work roll to deflect in the horizontal plane.

As shown in FIG. 3, the work roll deflection in the horizontal direction is expressed as a change in the roll gap in the width direction ΔG, which changes the shape of the sheet and the plate crown.

Recently, such an effect has been utilized in a rolling mill of the type shown in Fig. 4, which controls the shape and plate crown by offsetting the work roll 10 and controlling the horizontal deflection of the work roll with the press roller 11. was developed.

On the other hand, recent research has revealed that horizontal deflection of work rolls causes so-called herringbone. Herribone is a fine diagonal wrinkle as shown in Fig. 5, and is a phenomenon different from shapes such as middle elongation and edge elongation. For this reason, as shown in Figure 5, it is common for additional herringbones to occur in the middle elongation and edge elongation. With the so-called shape control described so far, it is possible to correct mid-elongation and edge warp, but it is impossible to correct herribone. From the foregoing, to be able to modify both the shape and the helibone requires both a conventional roll bending device in the vertical plane and a bending device in the horizontal plane.

Therefore, it is conceivable to simply combine the rolling mill shown in FIG. 1 with the rolling mill shown in FIG. 4, but this has the following drawbacks. In other words, in the rolling mill shown in Fig. 4, the work rolls are offset, so a component of the vertical pending force is applied to the horizontal pressing roller, and when p1 is added to the vertical bending chip, the horizontal deflection also changes. This makes control complicated. For the same reason, a component of the rolling load is also applied to the horizontal presser roller, and even if the rolling load changes, the horizontal deflection changes.

Furthermore, since the amount of offset of the rolls changes as the rolling load changes, there is also the problem that the accuracy of the plate thickness in the longitudinal direction decreases.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the drawbacks of such conventional methods and to provide a rolling mill having an effective shape and herribone correction function.

[Summary of the invention]

The present invention provides a rolling mill having at least one pair of work rolls, in which a first roller is disposed to press the central part of the work roll in the horizontal direction simultaneously from the front and rear along the running direction of the rolling mill, and By arranging second and third rollers that apply horizontal pushing force forward and backward at both ends, the work roll is always fixed on the roll center line and the work roll can be bent in the horizontal direction. The reason is that we have made it possible to do this.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A rolling mill which is an embodiment of the present invention will be described in more detail below with reference to the drawings.

FIG. 6 shows a rolling mill that is an embodiment of the present invention.

The basic work role is as shown in Figure 1.
This rolling mill has intermediate rolls 3 and 4 that are movable in the axial direction arranged between the rolls 92 and reinforcing rolls 5 and 6. Horizontal pressure roller devices 12, 13, 14, and 15 are arranged on the entry and exit sides of the work rolls 1 and 2. The structure of this presser roller device is a feature of the present invention, and an example thereof is shown in FIG. Fig. 7 is a view of the work roll 1 viewed from above;
It is supported in the horizontal direction by rollers 16, 17, 18, 19, 20.21. The rollers 16 and 17 that support the center of the roll are used to prevent the work roll 1 from shifting from the center of the mill, and the shaft box 22 and 23 are equipped with cylinders 28 and 29 that generate pressure for this purpose. It is being On the other hand, rollers 18 provided at both ends of the roll.
IL and 20.21 are for controlling the horizontal deflection of roll 1, and the pushing force of this reservoir is 24°25
and by cylinders 30.31 and 32.33 attached to 26.27.

The pressure roller arrangement [12, 13] consisting of these is fixed in a rolling-like housing 34,35.

It goes without saying that the pressure roller device 14,15 arranged on the other work roll 2 has exactly the same structure.

Next, a method of controlling the present presser roller device will be explained using the control block diagram shown in FIG. 8. Roller position detectors 36 and 37 are fixed to the axle boxes 22 and 23 of the presser rollers 16 and 17 in the center of the roll, and the output is set at a preset distance X! , The setting values XI and XQ are generally determined as Dw/2, respectively, assuming that the center of the mill is 0. Here, Dw is the diameter of the work roll. As a result, the presser roller 16.1
7 and the work roll are always in contact with each other, and the work roll is controlled so as to be centered in the mill. Note that in order to prevent backlash, XI and XO may be set as follows.

xl:Dw/2-α1”・”’ ”・(t)xo=Dw
/2−αo・・・・・・(2) Here α summer, α. is an extremely small value compared to Dw, and if α summer = α0, the work roll will be centered in the mill. Even more α! By changing .alpha.of and .alpha.of, a slight offset can be given to the work roll if necessary.

On the other hand, push roller 1 for horizontal roll bending
8.19 and 20.21 are controlled as follows.

That is, the command device 1 instructs the hydraulic power sources 42, 43, 44° 45 so that the hydraulic pressure applied to the cylinders 30, 31° 32, 33 becomes PI + P2 + P3, P4, respectively.
Give from t46. Depending on how P1 to P4 are set, the 9th
Various horizontal deflection states as shown in the figure can be realized. ′
First, FIG. 9(a) shows the case where P2 and P4 are added, and horizontal bending is given so as to be convex on the exit side in the rolling direction shown in the figure. Generally, bending in this direction is often applied for herribone correction. Next, Fig. 9(b) shows the case where Pl and P3 are given, and when the rolling direction is changed from Fig. 9(a) by reverse rolling,
Commonly used as a herlibone modification.

Of course, even when the rolling direction is the same as in (a), it may also be used for shape correction. FIGS. 9(C) and 9(d) both show cases where left-right asymmetric rolling is performed, and such horizontal bending is also possible if necessary. Furthermore, in FIGS. 9(a) and 9(b), it is also possible to provide asymmetrical bending by changing the sizes of P2 and P4, or Pi and P3, respectively.

The apparatus described so far is an example in which the present invention is applied to a conventional four-high rolling mill, etc. Next, an embodiment in which the present invention is applied to a rolling mill as shown in FIG. 1 will be described. In the case of such a rolling mill, the horizontal force Pa shown in FIG. 2 is applied from the intermediate roll 3. Now, considering the upper half of Fig. 1, if the intermediate roll 3 moves in the axial direction by δ as shown in the figure, F a will be Doesn't work.

FIG. 10 shows a top view of the rolling mill shown in FIG. 1.

In FIG. 10, the intermediate roll 3 located above the work roll 1 is shown by a dotted line, and the horizontal tangential force Fa acts only on the portion where these are in contact. Therefore, the horizontal deflection in this case is undesirably asymmetrical.

Therefore, in order to ensure symmetry, it is necessary to apply a force corresponding to the force in the shaded area in FIG. 10 in the opposite direction to Fa. This is naturally applied by the pushing roller 18 as shown in FIG. 11, and this force Q is as follows.

First, the resultant force FQ in the shaded area in FIG. 10 is as follows, and the distance LQ from the center of the mill to the point of action of FQ is as follows. Therefore, if the distance between the push rollers 18 and 20 is L, Q becomes = F a · δ/L (6). Further, the tangential force Fd in the horizontal direction can be determined from the force applied in the vertical direction, that is, the rolling load F and the friction coefficient μ between the rolls, as follows: F4=F・μ・mountain (7). Since μ is generally a constant of about 0.05 and F can be measured with a load cell, Fd is (
7) It can be calculated using Eq. On the other hand, as for the lower work roll 2, since the moving direction of the intermediate roll 4 is opposite to that of 3, it goes without saying that the work roll 2 has the shape of FIG. 10 upside down. Therefore, the roller to which Q is applied is also the roller on the opposite side of the lower work roll as shown in Fig. 11. Thus, in the rolling mill as shown in FIG. 1, in order to ensure left-right symmetry, it is necessary to always apply a force Qe in the same direction as the rolling direction to the push roller on the side where the intermediate roll moves. This Q is calculated from equations (6) and (7), Q=F・μ
- δ/L . . . It is given by (8) and is a function of the intermediate roll movement amount δ.

Therefore, FIG. 12 shows a horizontal roll bending adjustment mechanism in the rolling mill of FIG. 1. The basic device is the device shown in FIG. 8, which is made up of blocks that give commands regarding the previous Q. First, the position detector 47 provided on the intermediate roll 3 (indicated by the dotted line in FIG. 12) detects the intermediate roll position δ, and the calculator 48 calculates Q using equation (8). . On the other hand, since the direction in which Q is applied varies depending on the rolling direction of the material, the rolling direction is detected by the tachometer 49 connected to the work roll 1, and the direction in which Q is applied is determined by the calculator 50. As explained in FIG. 11, this direction is the same as the rolling direction. This Q command signal is
In addition to Pl or P2 provided from the command device 46, the hydraulic pressure source 42. of the push roller 18.19 is activated.
43. The other parts are exactly the same as those explained with reference to FIG.

FIG. 13 shows another embodiment of the present invention. In the example shown in FIG. 8, the axle boxes 22, 23 of the central roller 16, 17 are
Position detectors 36 and 37 were installed only at
9 and 20°21. That is,
Position detectors 51, 52, 53, and 544 are installed in the axle boxes 24, 25, 26, and 27, and their respective positions are xl.

Controller 55,5 so that X2 + X8 + X4
6°57.58, hydraulic power sources 42.43, 44. ”4
5 pressure is adjusted. According to this method, even in a rolling mill where asymmetry is a problem, such as the rolling mill shown in FIG. 1, the correction mechanism shown in FIG.
When trying to obtain a bending mode as shown in Figure (a), if NX2 and x4 are given as concentric values, the left-right symmetry of horizontal bending can be ensured. Note that the position detectors described so far are those attached to the axle box of the roller, but the same applies to a type of displacement meter 59 that directly detects the surface displacement of the work roll 1 as shown in Fig. 14. Needless to say.

On the other hand, it is possible to implement the present invention without using the displacement meter as described above. In other words, it is only necessary to consider the balance of forces applied by each roller. Figure 15 shows the respective forces in the furnace, and the following formula holds between them.

PI +P1 +P3 =Po +Pz +Pa +F
d..."・-(9) Transforming this, PI PO= (Ps 10Ps) 10P2 +P4 +
Fa...QI, the right-hand side of the QI equation is all known as described above. Therefore, the difference in the force applied to the presser rollers 16 and 17 in the center should always be adjusted to the value of formula (101).At this time, if the rolling direction changes, the FdO direction changes, and formula (11 is Pr -Pa -(P +Ps) +P2 +P4
It goes without saying that Fa −”・αυ.

Furthermore, as shown in FIG. 16, when the diameter of the work roll 1 is extremely small, support rolls 60 and 61 are arranged on both sides of the work roll 1, and the press roller device 12 is placed in contact with these support rolls.
, 13, 14, and 15.

As explained above, according to the embodiments of the present invention, the roles of each are clearly defined, such as the shape of the mid-off shore and edge elongation being controlled by conventional vertical bending, and the shape of the helibone being controlled by horizontal bending. The control becomes easier and the control effect becomes better. Therefore, it is possible to roll a completely flat material that is a flat plate without compound elongation and has no helibones, and the yield is greatly improved. Furthermore, since it is possible to use work rolls with a smaller diameter than before, the rolling load can be reduced, and the rolling reduction per pass can be increased, reducing the number of passes, etc., which also greatly contributes to energy savings. be able to. Also, for the same reason, the effects of the embodiments of the present invention are extremely wide-ranging and significant, such as making it possible to roll ultra-thin materials and hard materials that could not previously be rolled into good shapes. be able to.

It goes without saying that various modifications other than the examples described in the main text are possible without departing from the spirit of the present invention.

〔Effect of the invention〕

According to the present invention, it is possible to realize a rolling mill having correction functions for both the shape correction and the herribone correction of the rolled material.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram showing a six-high rolling mill to which the present invention is applied, Fig. 2 is an explanatory diagram illustrating how the work rolls deflect in the horizontal plane, and Fig. 3 shows that the horizontal deflection is the difference between the roll gaps. FIG. 4 is a schematic diagram showing a rolling mill of the type that controls the shape by horizontal deflection, FIG. 5 is an explanatory diagram showing a heribone, and FIG. A schematic diagram showing a six-high rolling mill as an example, FIG.
8 is a structural diagram showing the horizontal bending device for the work roll in FIG. 8, a control system diagram showing the horizontal pending force adjusting device in FIG. 7, and FIGS. 9(a) to (d)
Figure 10 is an explanatory diagram showing the relationship between the direction of the horizontal pending force and the deflection shape of the roll; Figure 10 is an explanatory diagram explaining the left-right asymmetry due to the movement of the roll; Figure 11 is a method for correcting the asymmetry. FIG. 12 is a control system diagram of a pending force adjustment device which is an embodiment of the present invention applied to a rolling mill as shown in FIG. 1, and FIGS.
The figure is a control system diagram of a pending force adjusting device according to another embodiment of the present invention, and FIGS. 15 and 16 are partial views of a rolling mill illustrating still another embodiment of the present invention. 1.2...Work roll, 3.4...Intermediate roll, 5
゜6... Helmet roll, 7... Rolling material, 8,9...
・Vertical bender, 10... Work roll, 11...
・Horizontal direction bender, 12, 13, 14, 15... Holding roller device, 16.17... Holding roller, 1
8゜19.20.21... Push roller, 22゜23.24, 25, 26.27... Roller axle box, 2
8.29, 30, 31, 32.33...Hydraulic cylinder, 34.35...Housing, 36.37...Position detector, 38.39...Hydraulic control device, 40°41.
42, 43, 44. 45... Hydraulic source, 46... Command device, 47... Intermediate roll position detector, 48... Arithmetic unit, 49... Tachometer, 50... Command device , 51°52.53.54...position detector, 55,56°57
．． 58...Hydraulic control device, 59...Roll surface position 3 Figure 4 Figure 6z Punishment) (b) (C) (d) Figure 10! Figure 11 Figure 74 3δ Kaya 15 ff@

Claims (1)

[Scope of Claims] 1. In a rolling mill having at least one pair of work rolls, first rollers are arranged to horizontally press the central part of the work rolls at the front and rear sides along the running direction of the rolled material. A rolling mill further comprising second and third rollers that apply horizontal pushing force forward and backward, respectively, at both ends of the work roll. 2. In claim 1, each horizontal valve pushing roller disposed at the end of the work roll is provided with a pushing force adjusting device independently, and the pushing force and direction of these rollers are mutually adjusted. A rolling mill characterized by being able to be changed to 3. In claim 2, the rolling mill is equipped with a moving roll that can move in the axial direction, and further includes a device for detecting the axial position of the moving roll, and a device for detecting the moving roll. A rolling mill comprising: a control device that operates each pushing force adjusting device for pushing the second and 30th rollers in the horizontal direction according to a value.