JPS61212418A - Method and installation for rolling - Google Patents

Abstract

PURPOSE:To improve the quality and yield of a product and to stabilize rolling operation by centering a rolling stock by a vertical mill and correcting its meandering by a horizontal mill before correcting further its camber by a vertical mill. CONSTITUTION:In a rolling installation, for rolling a rolling stock 9 by providing vertical mills 17, 18 to the inlet and outlet sides of a hydraulic rolling reduction type horizontal mill 10 respectively; the stock 9 is centered by the mill 17 and fed to the mill 10 as well as its meadering is detected by comparing the pressure difference between the hydraulic cylinders 15a, 15b of vertical rolls 13a, 13b with the aid of a comparison arithmetic unit 20. A correction signal is outputted from a meander-correcting device 21 in accordance with this detected quantity, and is compared with the displacement signals of displacement detectors 23a, 23b, to adjust a rolling reduction by actuating servovalves 22a, 22b in order to correct the meandering of stock 9. Further, the camber of stock 9 is detected by camber detector 25, and its correction signal is outputted from a camber correcting device 26 based on the detection signal, to adjust the pressures of hydraulic cylinders 16a, 16b of the mill 18 through comparison arithmetic units 29a, 29b.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a rolling method and an apparatus therefor capable of correcting meandering and camber of a rolled material.

[Conventional technology]

In rolling work, the rolled material cannot stay in the center of the roll due to the conditions during rolling and moves toward the end of the roll as the rolling progresses. There may be camber that bends to

Here, to briefly explain the meandering and camber of a rolled material, when rolling a rolled material using a rolling mill, there are various factors required for the rolled material itself, such as hardness differences in the width direction, thickness differences in the width direction, and temperature differences. unbalanced rolling loads applied to the work side and drive side of the rolling mill due to operational factors such as poor horizontal rolling leveling of the rolled material, and the center of the rolled material entering the roll with a deviation from the center of the roll (off-center). As a result, a difference occurs in the roll gap between the working side and the driving side of the rolling mill. Therefore, the drawing speed of the material on the entry side of the rolling mill is faster on the side where the gap is enlarged. As a result, the rolled material on the entry side tilts in a manner that swings its tail toward the wide gap side with respect to the advancing direction (direction of the arrow), as shown in Figure 5, and the inclined rolled material (α) is Since it advances perpendicularly to the axis of the roll (b), the rolled material (,) causes lateral displacement (meandering) in the direction in which the roll gap is widening, and the gap continues to widen. The state of the gap at this time is as shown in FIG. In this way, once the rolled material (,) has meandered, it will not be able to recover to a stable state.

By the way, although the peripheral speed of the work roll (b) is uniform on the left and right sides, in the case of Fig. 4, the roll gap on the left side is wide, so the volumetric flow rate of the rolled material (α) per unit time is on the left side. becomes larger. Moreover, if the thickness of the rolled material (α) at the entrance side of the rolling mill is symmetrical, the material will be drawn in faster on the side with a larger volumetric flow rate. As a result,
As shown in FIG. 5, the rolled material (,) moves to the left on the entry side (Δz), and camber (ΔV) occurs on the exit side. Further, even if the roll gaps on the work side and the drive side of the rolling mill, that is, the rolling reduction ratios on the left and right sides are the same, camber (Δy) occurs due to the difference in the advance ratio on the left and right sides caused by the rolled material (α) itself.

Since camber is generated in this way, the difference in the roll gap between the left and right sides also becomes larger, and the rolled material (α) meanders more rapidly toward the left end, and the camber also increases accordingly.

In order to prevent such meandering and the accompanying camber, it is effective to roll the rolled material (α) under conditions such that a convex crown is formed. However, in recent years, as it has become more difficult to improve the quality and yield of rolled materials, it has become necessary to reduce the convex crown as much as possible and to roll the material so that it has a uniform thickness distribution in both the longitudinal and width directions. Under such conditions, the rolled material tends to meander, making stable operation difficult.

In recent years, one of the methods to prevent meandering has been to detect the force applied to the left and right load cells (c) and (d) (see Figure 4) when the rolled material meanders, which changes the force applied to the left and right load cells (c) and (d) (see Figure 4). A method has been proposed in which the rolling down device is moved to narrow the roll gap on the side where the load is increased to try to prevent this.

[The invention solves [-the problem it attempts to solve]]

However, this method has problems such as the output change due to meandering being mixed with the output change due to the operation of the lowering device, the control system is unstable and tends to cause divergent vibration, and the accuracy is insufficient and completely The drawback is that it is not practical.

Regarding camber, even if the meandering of the rolled material described above can be sufficiently prevented, the material of the rolled material is asymmetrical, the material itself has camber, and there is a temperature difference between the left and right sides. It also occurs due to things such as Conventionally, no correction methods have been developed for this problem, and the countermeasure is to obtain a rectangular thick plate of the required dimensions by rolling the plate to a sufficiently large width and cutting off unnecessary parts. This resulted in a significant drop in yield.

The present invention was developed in view of these circumstances, and aims to prevent meandering through stable control and correct camber, thereby improving quality, yield, and stabilizing rolling operations. be.

[Failure to solve the problem]

In the present invention, in a rolling equipment equipped with vertical rolling mills before and after a horizontal rolling mill, the rolled material is fed into the horizontal rolling mill while being centered by the vertical rolling mill on the entry side of the horizontal rolling mill, The load difference generated by the rolled material acting on the left and right vertical rolls of the vertical rolling mill on the entry side is determined, and the work rolls of the horizontal rolling mill are leveled to correct the meandering so that the load difference is eliminated. The camber is corrected by applying horizontal bending to the rolled material using the vertical rolls of a vertical rolling mill.

[For production]

Therefore, in the present invention, the rolled material is centered by the vertical rolling mill on the entry side of the horizontal rolling mill, and the work rolls of the horizontal rolling mill are Leveling is performed to correct meandering, and camber is corrected by the vertically rolled material on the exit side of the horizontal rolling mill.

〔Example〕

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

FIGS. 1 and 2 show an embodiment of the present invention. The bottom of the chubby prowl chock (5
) (6) , a hydraulic vertical rolling machine α equipped with a hydraulic cylinder (71 (81) that acts a rolling blade on each roll chock (5) (6), and configured to roll the rolled material (9)
1, and vertical roll yoke (11, Z) (11b), (12LL) (
12b) supported by vertical rolls (13a) (13b
), (14cL) (14b) in the width direction of the rolled material (9) using hydraulic cylinders (15α) (15b), (16α) (16
A vertical rolling mill 0η0 barrel that can be rolled down according to b) is installed.

A pressure detector (19α) (19b) is connected to a cylinder (15α) (15b) of a vertical rolling mill 0η, and a pressure detector (1
9α) (196) is detected by the comparison calculator (1
) to perform a comparison operation and perform left and right vertical rolls (13α) (13b)
The load deviation can be determined, and the load deviation can be sent to the meandering correction device Cυ, and the left and right hydraulic pressure 7 cylinders (71 (81) are connected to servo valves (22 (Z) (22b)), and the hydraulic pressure is The amount of pressure oil flowing into and out of the cylinders (7) and (8) can be controlled, and the hydraulic cylinder +7)
(Displacement detector that detects the movement of the 81 pistons (2k
) (23b) is attached to the hydraulic cylinder (71 (81), and a comparison calculator (24α) (246) is used to compare the displacement signal from the displacement detector (23α) (23b) and the reduction correction signal from the meandering correction device Cυ. Servo valve (22α) (22b)
Connect to.

A camber detector (c) is arranged on the exit side of the vertical rolling mill Ql so that the detection signal of the camber detector (c) can be sent to the camber correction device (to), and the left and right hydraulic cylinders (
Servo valve (27α) (27b) on 16α) (11Sb)
Connect 17, said hydraulic cylinder (16cL) (16b)
Displacement detectors (28α) (28b) are installed on the hydraulic cylinder (16α) (16b) to control the amount of pressure oil flowing into and out of the hydraulic cylinder (16α) (16b) and to detect the movement of the piston of the hydraulic cylinder (16α) (16b). Install the displacement detector (28
α) Displacement signal from (28b) and camber correction device (2
Comparison calculator (29) that compares the camber correction signal from e.
α) (29b) is connected to the servo valve (27→(27b)).

In the figure, (7) is the meandering detector on the entry side, (31α) (3
1b) is the displacement detector of the hydraulic cylinder (15cc) (15b), (32c) (32b) is the hydraulic cylinder (16α)
At the start of rolling, the hydraulic cylinder (15α bar 15b) of the horizontal rolling mill α Combine = b vertical roll (13α) (1
3b) and adjust the gap between the vertical rolls (13α
) (13b) to center the rolled material (9), and roll with the gap between the vertical rolls (14α) (14b) of the α barrel of the vertical rolling mill wider than the width of the rolled material (9). Start.

During rolling, the pressure signal detected by the pressure detector (19α bar 19b) is sent to the comparator (a), and the comparator (a) compares the left and right pressure signals. If there is no meandering in the rolled material (9) on the entry side, the pressure detected by the pressure detectors (19α) (196) is equal on the left and right sides, so no signal is output from the comparator; Therefore, the hydraulic cylinders (7) and (8) do not operate, and rolling continues without changing the left and right gaps of the work roll fil (2).

However, if the rolled material (9) meanders at the entrance side of the horizontal rolling 15 ill, a difference will occur in the signals detected by the pressure detectors (19α) (196), and the load deviation signal from the comparator will meander. Sent to correction device Qυ, meandering correction device C
It is processed by υ and sent to a comparator (24α) as a reduction correction signal.
) (24b), and the comparator (24α) (24
In b), the piston displacement signal of the actual hydraulic cylinder (force (8) and the reduction correction signal are compared, and the difference signal causes the servo valves (22α) (22b) to act on the hydraulic cylinder (7) (
As a result, the left and right roll gaps of the work roll (11 (21) are changed to adjust the left and right leveling, and the rolled material (9) is returned to a predetermined position ( meandering correction).

The rolled material (9) rolled by the hydraulic rolling mill is sent to the subsequent process via a camber detector (c).
), the camber is detected by the camber detector (C), and the signal is sent to the camber correction device (1), processed by the camber correction device (C), and subjected to comparison calculation as a camber correction signal. (29α) or (29b). For example, if the rolled material (9) has a camber as shown by the two-dot chain line in Fig. 2, the camber correction signal is compared with the piston displacement signal of the hydraulic cylinder (16) in the comparator (29b). Based on the differential signal, the servo valve (27b) controls the amount of pressure oil flowing into the hydraulic cylinder (16), and as a result, the vertical roll (14) advances toward the rolled material (9) and the rolled material (9). ) to eliminate camber (camber correction) 0 In this way, the vertical rolling mill αDa barrels are installed on the entry and exit sides of the horizontal rolling mill α1, so that the rolled material (9) is always rolled at the center. A vertical rolling mill αηα is used to prevent the bag from being off-centered.
Because it is controlled by barrels, stable rolling is possible without meandering or camber. In particular, in a shift mill where the work roll is shifted in the e-axis direction and rolling is performed by aligning the work roll barrel end with the plate end, if the material shifts from the center, even if it shifts and becomes stable, the width edge of the rolled material However, by centering the rolled material and completely preventing meandering as in the present invention, rolling in a shift mill can also be performed well. I can do it.

Correcting the camber in a vertical rolling mill on the exit side of a horizontal rolling mill is thought to be difficult when the width of the plate is wider compared to the thickness, as the plate is more likely to buckle. It can be easily bent by applying a lateral bending moment using a vertical rolling mill a8. This is because there is a phenomenon in which the bending moment required for correction is significantly reduced by adding a reduction blade.

As a ripple effect of the vertical rolling mill, by driving the vertical rolling mill aη on the horizontal rolling mill 01 side and pushing the rolled material (9) between the work rolls +11 (2), the material is bitten. It is possible to overcome the limits (biting slip in a normal mill or torque transmission slip between the intermediate roll and work roll in an intermediate roll drive mill). In other words, there is a limit to the amount of biting per pass due to the frictional force between the rolled material (9) and the work roll +1) <2>, which inevitably requires a large number of reverse passes, so it is difficult to save labor in the rolling process. V4 becomes an obstacle. However, if rolling is started after the biting limit is overcome, in simple theory, α will be 21, and it will be possible to break through the biting limit. Here, α is the bite angle during rolling, and f is the friction angle between the rolled material and the roll.

In addition, in the embodiments of the present invention, the case where the rolled material is sent only in one direction has been described, but it can also be applied to cases where reverse rolling is performed, and it can be applied to plate mills and other rolling mills. It goes without saying that various changes may be made without departing from the spirit of the invention. Furthermore, it goes without saying that the meandering control means is not limited to work roll leveling, and other means such as roll bending can be used.

〔Effect of the invention〕

According to the rolling method and apparatus of the present invention, the center of the rolled material always matches the center of the rolling line and meandering and camber generation can be prevented, so stable rolling is possible, especially in work roll shift mills. Since the rolled material does not come off the end of the roll barrel, good rolling can be performed, and quality and yield can be improved.
It can produce excellent effects.

[Brief explanation of the drawing]

Figures 1 and 2 are detailed explanatory diagrams of the present invention, Figure 3 is a plan view showing the inclination of the rolled material when there is a difference between the roll gaps on the left and right sides of the horizontal rolling mill, and Figure 4 is a plan view showing the inclination of the rolled material when there is a difference between the roll gaps on the left and right sides of the horizontal rolling mill. FIG. 5 is an explanatory view of the case where the roll is moved toward one end side, and FIG. 5 is a plan view thereof. fl in the figure) (21 is a work roll, (7) (81 is a hydraulic cylinder, (9) is a rolled material, α1 is a hydraulic horizontal rolling machine, (15a) (136) (14cL) (14b)
are vertical rolls, (15a) (15b) (16cL) (16
b) is a hydraulic cylinder, αη decoy is a vertical rolling mill, (19α)
(196) is a pressure detector, (to) is a comparison calculator, Qll
is a meandering correction device, (22α) (22b) is a servo valve, (
23α) (236) is a displacement detector, (24α) (246
) is a comparator, (c) is a camber and ba detector, (to) is a camber correction device, (27a) and (27b) are servo valves,
(28(1)(28b) is a displacement detector, (2%)(29
b) shows a comparison calculator.

Claims (1)

[Scope of Claims] 1) In a rolling facility equipped with vertical rolling mills before and after a horizontal rolling mill, the rolled material is centered by the vertical rolling mill on the entry side of the horizontal rolling mill, and the rolled material is then rolled through the horizontal rolling mill. Send it to
The load difference generated by the rolled material between the left and right vertical rolls of the vertical rolling mill on the entry side is determined, and the work rolls of the horizontal rolling mill are leveled to correct the meandering so that the load difference is eliminated. A rolling method characterized by correcting camber by applying lateral bending to a rolled material using vertical rolls of a die rolling mill. 2) Vertical rolling mills installed before and after the horizontal rolling mill,
A comparison calculator that calculates the difference in the load acting on the left and right vertical rolls of the vertical rolling mill on the entrance side of the horizontal rolling mill, and a hydraulic cylinder for rolling of the horizontal rolling mill if there is a deviation in the results calculated by the comparison calculator. A meandering correction device that levels the work roll by operating to eliminate deviation, a camber detector installed near the vertical rolling mill on the outlet side of the horizontal rolling mill, and a camber detected by the camber detector that eliminates the camber. 1. A rolling apparatus comprising: a camber correction device for imparting lateral bending to a rolled material by vertical rolls of a vertical rolling mill on the exit side of the horizontal rolling mill.