JPS59185514A - Control device for transverse stiffness - Google Patents

Abstract

PURPOSE:To roll a rolled plate having a flat crown shape by making the pressing force of horizontal pressing rolls changeable according to the signal of a load cell thereby adjusting freely the deflection of the rolls in the transverse direction. CONSTITUTION:When a rolled plate 23 is rolled under required rolling force PR, the rolling load is detected by a load cell 15, and is inputted in the form of roll bending force PB to an adding amplifier. A function KB/Q corresponding to the plate width is applied to the 1st calculator 16 by the signal from a setter 19 for transverse stiffness and plate width. The force PR is introduced into the 2nd calculator 17 which calculates the ratio KL/Q between the coefft. KL of a lateral bending effect and the transverse stiffness Q of the work roll and inputs the same to a setter 22 for the pattern of the pressing force on a horizontal cylinder. The offset distance between work rolls 5, 6, the balance value of lateral bending rolls determined by the 3rd calculator 18 and the tension difference calculated in accordance with the tension on the outlet and inlet sides of the rolled plate detected with tension detectors 24, 25 are inputted thereto and the pressure on the lateral cylinders is controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a lateral stiffness control device in an offset rolling mill.

The lateral rigidity of a rolling mill is a concept that represents the amount of deflection in the roll width direction due to rolling force, and is defined by the following formula.

As shown in Fig. 1, the lateral rigidity Q of this rolling mill changes depending on the strip width, and the groove bending effect coefficient KB also changes depending on the strip width, so the rolling force PR and the roll pending cup pB change. It is difficult to properly seek relationships.

If the lateral stiffness of the rolling mill can be maintained at an optimal value regardless of the strip width, the strip crown can be minimized against rolling force disturbances, heat crown, and roll wear.

This concept will be explained with reference to FIG. 2 (in the figure, the vertical axis shows the rolling force, and the horizontal axis shows the amount of crown variation).

That is, as shown in Fig. 2 (α), the rolling force increases (PR, →
Corresponding to PR2), if the lateral rigidity is kept high from Q1 to Q2, it is possible to roll with a constant crown ratio. Further, as shown in FIG. 2(b), for the heat crown (CH), rolling with a constant crown ratio can be achieved by lowering the lateral rigidity from Q to Q3. Furthermore, when rolling the entrance plate crown zero, the lateral stiffness f is changed as shown in Fig. 2(c).
If you increase Q to infinity from Qco, Heat Crown (
Decrease bending (2) is required to cope with CH), which may be impractical, but even in this case, if the rolling mill is given an appropriate lateral rigidity (for example, Q3), increase bending (I) can be achieved. It is possible to control the plate crown relative to the heat crown within this range, making it easy to roll flat or round-shaped plates.

However, in a conventional 5-high or 6-high offset rolling mill that is equipped with a work roll or an intermediate roll offset with respect to the axes of the upper and lower backing rolls and a horizontal intermediate roll and split rolls that support the offset rolls, the above-mentioned The concept of lateral stiffness control had not yet been introduced, and the horizontal pressing force by the lateral stiffness was only adjusted based on the relationship between the rolling force, the radius of the offset roll, the offset distance, etc.

Therefore, the plate crown fluctuates due to rolling force disturbance, heat crown, roll wear, etc., making it impossible to roll a flat or round-shaped plate.

The present invention was made for the purpose of eliminating the above-mentioned drawbacks of the conventional offset rolling mill, and it is possible to maintain the lateral rigidity of the offset rolling mill uniformly without being affected by the strip width.
Furthermore, the present invention relates to a lateral stiffness control device that can control only lateral stiffness without affecting vertical stiffness.

The basic idea of the present invention will be explained below.

The relationship between the lateral rigidity of a rolling mill and crown disturbance is considered as follows.

Q: Lateral rigidity (Ton/mm) PR: Rolling force (Ton) Cr: Exit plate crown (m'm) C1: Initial crown (mm) PB: Roll pending force (Ton) KB: Bending effect coefficient (Ton/mm) ) ST; Horizontal presser force (To
n) KL: Horizontal bending effect coefficient (Ton/mm) From the above formula, it can be seen that the outlet plate crown Cr is determined by the lateral rigidity of the rolling mill, rolling force, roll shape, roll pending force, horizontal pressing force, etc. - In the above, the roll pending force pB and the horizontal pressing force ST are respectively expressed by the following formulas.

Substituting these into equation (1) yields the following. Here, CI=0, α1′, 0.5, α2嬌0
．． 5, if Q' is controlled to be infinite, C
r becomes 0.

Therefore, by controlling the lateral rigidity of the work roll, it is possible to control the plate crown to a constant value.

If the lateral stiffness control device is configured based on the above principle, the sixth
It will look like the figure.

In Figure 3, (1) and (2) are upper and lower rolls, (3)
(4) are upper and lower intermediate rolls; 7)
(8) are the upper and lower horizontal intermediate rolls that contact the core upper and lower work rolls (5) (6) from the horizontal direction, (9) Q* are the upper and lower divided rolls for applying horizontal pressing force, and αυ ( stomach)
are the upper and lower lateral cylinders that move the upper and lower divided rolls (9)◇Q, and α3a→ are the upper and lower intermediate roll shaft boxes.

A funnel hand aυ is provided on the axle box of the upper holding roll @),
The rolling force detected by the load cell 00 is
the sixth arithmetic unit α0αηα8), and the first arithmetic unit 0
At 0, KB/Qi is calculated from the value set by the lateral rigid plate width setting device 0 and the rolling force, and the calculated value is sent to the soil and lower work roll bending crack 11) so that the pending force can be adjusted. , and KL/Q from the value set by the lateral stiffness plate width setting device 0 in the second computing unit q force.
' is calculated and the calculated value is sent to the horizontal cylinder presser cover turn setting device (A) for the upper and lower lateral cylinders (1, 1) (
The presser foot force of 12 can be adjusted, and the 6th computing unit 0
In 8), the offset distance of the work rolls, the sum of equivalent roll radii (i.e. the sum of radii of upper and lower work rolls) i
The calculated lateral venting roll balance value 'c is sent to the horizontal cylinder presser cover turn setting device (A) for the upper and lower lateral cylinders α1) (6
) so that the presser foot force can be adjusted.

Furthermore, the upper and lower work rolls of the rolling board (5) (6)
Tension detectors (C) (C) are installed on the inlet and outlet sides,
The tension difference (Tf - Tb)/2 from the exit tension Tf and the entry tension Tb of the rolled plate detected by the tension detector (c) (c)
is calculated by the comparison calculator (A), and the calculated value is sent to the horizontal cylinder presser cover turn setting device (A) so that the presser force of the upper and lower lateral cylinders (1] and (2) can be corrected. be.

The work roll bending pressure set value set by the heat crown prediction formula etc. is input into the upper and lower intermediate roll shaft boxes α3q4), and the work roll bending pressure is adjusted by the work roll bending pressure balance setting device Q. The initial setting is the balance pressure.

When rolling with an offset rolling mill equipped with the lateral stiffness control device of the present invention, the work roll bending pressure is set in advance using a heat crown prediction formula or the like. At this time, the initial setting of the work roll bending balance is set to the lance pressure. Here, upper and lower work rolls (5
) (6') is a hydraulically driven increase bender and decrease bender that uses the difference in force to create a concave or convex car.
This bending pressure is detected by a pressure transducer, the difference is calculated by an amplifier and fed back, the servo amplifier adds it, and a gain is given to control it by a servo valve. I have to.

When the rolled plate (A) is rolled with the required rolling force pR, it is detected as a rolling load by the load cell aO, which is input to the summing amplifier as a roll pending coefficient pB via a lateral stiffness coefficient setter and a function unit.

The first computing unit 00 is given a function KB/Q according to the board width by a signal from the lateral stiffness board width setter 09), and a fixed lateral stiffness coefficient C is set in the lateral stiffness coefficient setter 09). These are connected and operated so that the optimum gain is output from the servo amplifier.

Also, the rolling force PRk is introduced into the second calculating unit α, and the lateral bending effect coefficient Kt and the ratio KL/Q'f of the work roll lateral stiffness Q are calculated and input to the horizontal cylinder presser cover turn setting device (A). At the same time, attach the work roll (5) (6) to the horizontal cylinder presser cut turn setting device (A).
) from the offset distance C and roll radius of the sixth arithmetic unit (
Calculated by a comparator (a) based on the lateral venting roll balance value obtained in step 18), and the outlet tension T/ and inlet tension Tb of the rolled plate detected by the tension detectors (c) and (c). Tension difference (Tf-Tb)/2'! Enter z to control the lateral run cylinder pressure. This results in
By keeping the gear knobs of the upper and lower work rolls (5) and (6) constant, a flat rolled plate with a constant plate thickness and plate crown can be obtained.

Note that the lateral stiffness control device of the present invention is not limited to the above-described embodiments, and is not limited to an offset 6-high rolling mill that offsets the upper and lower work rolls, as well as an offset machine that offsets the small diameter work rolls. It goes without saying that various changes may be made without departing from the gist of the present invention, such as application to a 5-high rolling mill.

As described above, according to the lateral stiffness control device of the present invention, in a rolling mill having a horizontal valve roll that supports a jaw offset with respect to the center of the holding roll, the widthwise flexure in the horizontal and vertical directions is reduced. A device that calculates the amount to correct the amount of sag from the signal of the load cell (which detects the rolling force) U.
Since the holding force of the horizontal valve roll can be changed according to the signal, the deflection of the roll in the width direction can be freely adjusted and the lateral rigidity can be automatically adjusted, and disturbances in the strip width, rolling force, etc.
It exhibits various excellent effects, such as being able to roll a flat or round-shaped rolled plate by reducing fluctuations in the plate crown due to heat crown or roll abrasion.

[Brief explanation of drawings]

Figure 1 is a diagram showing the relationship between lateral stiffness and board width, and bending effect coefficient and board width. Figure 2 (α), (b), and (c) are diagrams showing the effect of lateral stiffness. FIG. 2 is an explanatory diagram of a lateral stiffness control device of the present invention. In the figure, (5) and (6) are upper and lower work rolls, (7) (
8) are the upper and lower horizontal intermediate rolls, (9) αO is the upper and lower divided rolls, αO is the load cell, and Q! is the first computing unit, 0η is the second computing unit, α frame is the sixth computing unit, (A) is the horizontal cylinder presser cover turn setting device, (C) (C) is the tension detector, Q
is the lateral stiffness, PRp rolling force, PBU roll pending force, and KB is the bending effect coefficient. Patent applicant Ishikawajima Harima Heavy Industries Co., Ltd. Plate width (mm)

Claims (1)

[Claims] 1) In a rolling mill having a horizontal presser roll that supports a roll offset with respect to the center of the backing roll, the amount to correct the amount of deflection in the width direction in the horizontal and vertical directions is
It is equipped with a device that calculates the rolling force from the signal of the load cell that detects the rolling force, and also changes the pressing force of the horizontal presser roll according to the signal, freely adjusting the deflection of the roll in the width direction, and automatically adjusting the lateral rigidity. Features an adjustable configuration.
Characteristic lateral stiffness control device.