JPS61176412A - Setup method in control of different peripheral speed rolling - Google Patents

Abstract

PURPOSE:To set up rolling conditions at high speed in the control of different peripheral-speeds rolling, by operating a roll opening and each roll peripheral speed at the time of different peripheral speeds from the sheet thickness of a stock to be rolled, the sheet thickness after rolling and the aimed rolling load in the different peripheral speeds rolling, and setting respective values to the operated values. CONSTITUTION:The setup of different peripheral-speeds rolling for rolling a stock to be rolled by passing the stock between a pair of rolling rolls and driving the rolls at different peripheral speeds is performed in the following manner. That is, a rolling load P is represented by a correction term DELTAP including a rolling torque G* and a different speed ratio, at the time of equal speeds rolling as parameters. Further, rolling torques TL, TN are represented by correction terms DELTAGL, DELTAGN including the rolling torque G* and the different speed ratio, at the time of equal speeds rolling, as parameters. And a different speed ratio capable of obtaining a maximum volumetric speed is operated under the conditions that the rolling load and torque are in allowable ranges. Next, a roll opening is further operated from a rooling force obtained by said operation to set the roll peripheral speed and the roll opening obtained by said operation.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a set-up of so-called different circumferential speed rolling control, in which rolling is performed by varying the circumferential speeds of a pair of rolling rolls.

[Background of the invention]

Conventionally, rolling mills have conventionally been operated with the upper and lower rolling rolls having the same circumferential speed.

(Hereinafter, this rolling will be referred to as uniform speed rolling to distinguish it from different circumferential speed rolling.) However, the limit of conventional uniform speed rolling was that it could be rolled to a thickness of several hundred micrometers. In recent years, there has been a demand for rolling to a thickness of 100 micrometers or less, and it is theoretically and experimentally clear that it is possible to achieve ultra-thin rolling that satisfies the above requirements by increasing the circumferential speed of the upper, lower, and rolling rolls. It has been.

However, a control method for this kind of rolling has not been established, and in order to establish a calculation control system equivalent to that of conventional constant speed rolling, it is necessary to control rolling mill settings, plate thickness during rolling,
Control methods such as tension control or adaptive correction control must be developed and put into practical use.

Particularly in the case of different circumferential speed rolling, the speed setting and rolling position setting of the pair of rolling rolls have mutual interference with other parameters, so the operator repeats the settings minute by minute through trial and error until the final target position is reached. This is the current situation.

When performing computer control, it is a major problem that setting operations are difficult to determine, and it has been desired to establish a setting control method suitable for computer control.

Based on the load distribution between the rolls at the speed ratio of the upper roll and lower roll given as a setup method, calculate the neutral point position (angle) of each of the low and high speeds, and make sure that the neutral point (corner) on the high speed side is zero. The rolling force is calculated under the condition that the neutral point (angle) on the low speed side is larger than the contact angle on the low speed side, and the roll circumference of each of the rolling rolls is calculated from the given exit rolling material speed and the neutral point position. There is a method of calculating the speed and setting the calculated roll circumferential speed and roll opening degree.

In the above method, the load distribution between the rolling rolls changes depending on the roll flattening amount, and the roll flattening amount depends on the rolling load obtained by integrating the load distribution, so convergence calculation is required. This convergence calculation has the problem of requiring a lot of processing time.

In addition, in Japanese Patent Publication No. 54-42761, ``In metal rolling, the speed ratio of the two work rolls is adjusted on the entry side so that the rolling torque is within the maximum permissible torque range that can be transmitted by the two rolls. ``A rolling method characterized in that rolling is performed by selecting as large a material as possible within a range less than the sheet thickness at the outlet side'' has been reported.

Figure 2 shows the rolling torque when the peripheral speed ratio of the two rolling rolls is changed while keeping the input side plate thickness, exit side plate thickness, input side tension, exit side tension, etc. constant. As is clear, as the true speed ratio increases, the rolling torque of the high-speed rolling rolls increases rapidly, and on the other hand, the absolute value of the rolling torque of the low-speed rolling rolls also increases rapidly. Therefore, as the true speed ratio increases, it is necessary to lower the rolling speed to within the range of the motor rating.

[Purpose of the invention]

The purpose of the present invention has been made in view of this point,
An object of the present invention is to provide a high-speed setup method for controlling rolling at different circumferential speeds.

[Summary of the invention]

The feature of the present invention is a rolling process that includes at least a pair of rolling rolls and rolls and rolls a material to be rolled by passing the material between the pair of rolls, and each of the pair of rolling rolls is driven at a different circumferential speed. In the setup method for true speed rolling,
The rolling load P is expressed by the rolling load P' during uniform rolling and the correction term ΔP with the true speed ratio as a parameter, and the rolling torque T,
, T, is expressed by the rolling torque G1'' during uniform rolling and the correction term 10L, AGIl, which uses the true speed ratio as parameters, and the maximum volume speed can be obtained while the rolling load and rolling torque are within the allowable range. Calculate the true speed ratio, calculate the rolling force from the calculated true speed ratio, calculate the roll opening from the calculated rolling force, and set the calculated roll circumferential speed and roll opening. There are certain characteristics.

[Embodiments of the invention]

First, we will discuss the basics of rolling at different circumferential speeds.

The rolling situation directly below the rolling roll during rolling at different circumferential speeds is shown in the third table.
As shown in the figure. 1 is the upper roll of a pair of work rolls, 2
indicates the bottom roll. ■ is an advanced area, ■ is called a new castle, and ■ is a backward area, and it has these three areas. The boundary between each area is called the neutral point, and at the boundary between the advanced area and the new area, the roll circumferential speed on the high-speed rotation side of the upper and lower rolling rolls and the rolling material speed at that point match, and at the boundary point between the backward area and the new area, the rolling material speed at that point is the same. The peripheral speed of the roll on the low speed side and the rolling material speed at that point match.

The position of this neutral point is expressed by the roll angle from the rolling completion point (rolled material exit), and is defined as φ, φ1, respectively.

The vertical stress p is expressed by the following formula.

p=A (B+C) ・・・・・・(
1) However, A and B are roll angles θ (or θ yo),
Outlet thickness, roll radius RL, R,, friction coefficient μ.

μ8 and shear yield stress are functions of τ, orientation coefficients α and β, and C is an integration constant. The integral constant C is determined by the boundary conditions of each region.

Distribution load curve (1) equation in each rolling region and.

The neutral point position φ,, φ, is the entrance thickness H1 and the entrance unit tension t.
b, exit side thickness h, exit side unit tension 1. and the reprint of the above specification (no change in content) Uniquely determined by giving the lower roll speed ratio.

Furthermore, the high-speed side advancement rate fR1 and the low-speed side advancement rate ft can be given by the following equation further than φ■ and φL.

Furthermore, once the distributed load curve is determined, the total rolling force P is
It is given by integrating the normal stress p over each region.

i.e. However, the total contact angle φ1 is determined by equation (5).

Reprint of specification (no change in content) The relationship among the rolling position S, the total rolling force F, and the exit thickness h is based on the well-known Hooke's law.

h=s+P/M So -.'' (6) where 1M: Mill stiffness coefficient So: Zero adjustment value of reduction Total rolling force P is expressed by equation (7).

P=P umbrella (He h, tb, tt
)−ΔP(le h, tb, tf, Gll)
...Group (7) However, *P'': Total rolling force during uniform rolling (calculated using a conventionally known formula) ΔP: Total rolling force correction term for different true speeds Also, on the high speed side ( or low speed side) rolling torque GM (or GL
) is expressed by equations (8) and (9).

Gs, =G filial (ru ht tb + tf) - ΔGt,
(H, h, tb, tt, G-) --(
8) Gi = (G umbrella (H, h, tb,
tt )+40m (le he t,, t,, Qv
) ......(9) However, The":
Rolling torques ΔGL, ΔGH during uniform speed rolling: low speed roll side during true speed rolling, high spec. .

Total rolling force P'f! :,, Calculated off-line while changing the entry thickness H9, exit thickness, front and rear unit tension 't*'bt, and calculate the total rolling force P during true speed rolling and the total rolling force P during constant speed rolling. It was found that the difference in can be approximated by a quintic equation regarding the true speed ratio G. This is shown in Fig. 4. Also, a known formula was used for the total rolling force P during constant speed rolling. [Okay, I hope this will allow you to quickly calculate the total rolling force P.

The same holds true for the formulas for determining the rolling torque and advance ratio, and the difference between the values during true speed rolling and the constant speed rolling could be approximated by a quintic equation regarding the true speed ratio G7.

Father, by calculating the advance rate ft for the low-speed side roll expressed by equation (3) off-line,! 1
Expressed in trials.

ft,=ft,” ()L h・1−.1.)+dfL
Umbrella (H, h, tb, tt, G-)...
...α, f, *: Advancement rate 1st during uniform rolling
The figure is an example of the true speed rolling-setting value calculation order in setting control when there is only one rolling stand.

In step 41, rolling schedule (inlet thickness H9 outlet thickness, plate width b) inlet and outlet unit tensions 1. ．． Input the 1° rolling roll radius at, , Rmfc.

In step 42, the minimum true speed ratio 'tEGvwa1m at which the rolling load is within the allowable range is determined using equation (7).

In step 43, the maximum true speed ratio G v east at which the rolling torque of the high-speed side roll and the low-speed side roll falls within an allowable range is determined.
is determined using equations (8) and (9).

In step 44, the rolling torque GL at the true speed ratio G,
Gl and the advance rate fX on the low speed roll side are (8), (
9), is determined by the formula 01, and the rolling exit plate speed Vo at this true speed ratio, which is limited by the motor power, is determined by the formula α1.

...Value υ However, FF%axM g FPmaxL i Allowable amount a
x Motor power specification - engraving (no change in content) - When the output side is low speed or high speed, the amount of rolling per unit time by one rolling mill is maximum.

The true speed ratio is within the range of Gvnl a to G, □8, and the true speed ratio G is determined such that the stand exit speed Vo determined by the αυ formula is the maximum.

In step 45, the rolling load P for the true speed ratio determined in step 44 is calculated using equation (8).

In step 46, the rolling force S determined in step 45 is used to calculate the rolling position S from equation (6).

In step 47, the low speed side advance rate fL with respect to the true speed ratio determined in step 44 is calculated using the il1 formula, and na.

(Calculate the roll circumferential speed using formula 131.

Vn*=Vmt, -G, =Q3 However, Vat: Low speed side roll circumferential speed v■: High speed side roll circumferential speed In step 48, step 46.47. e Set and output the calculated rolling down position S and roll circumferential velocities vIH and vIL.

Revision of specification (no change in content) Even when rolling at different circumferential speeds is performed, when the material to be rolled is first rolled, uniform speed rolling is performed in consideration of threadability.

Setup calculation for this constant speed rolling state can be performed by a known method, and the rolling position and speed at this time are also set and output. (Details are omitted.) An example of the transition process from 5-uniform speed rolling to different peripheral speed rolling is shown in FIG. In the case of this figure, it is shown that the plate could not be rolled to the target thickness by constant speed rolling, but could be rolled to the target plate thickness by true speed rolling.

This embodiment describes a rolling mill with only one stand, but also applies to a rolling mill row with multiple stands.

A similar setup method for rolling at different circumferential speeds can be applied.

〔Effect of the invention〕

According to the present invention, the circumferential speed of the roll during rolling at different speeds.

Setup calculation of the rolling position can be processed faster than in the conventional method.

[Brief explanation of the drawing]

Fig. 1 shows an example of the control calculation procedure of the present invention, and Fig. 2 shows an example of the control calculation procedure of the present invention.
Figure 3 shows the relationship between rolling torque and true speed ratio, Figure 3 shows the distribution of rolling phenomena in the present invention, and Figure 4 shows the total pressure P using equation (4).
An example of calculation using equation (7) is shown in FIG. 5, and FIG. 5 shows an example of the transition process from constant speed rolling to true speed rolling. 1.2...Top roll, bottom roll.

Claims (1)

[Claims] 1. Different circumferential speed rolling, which has at least one pair of rolls and performs rolling by passing the material to be rolled between the pair of rolls, in which each of the pair of rolls is driven at different circumferential speeds. In the rolling setup method, the rolling load during different peripheral speed rolling is the sum of the rolling load during uniform speed rolling and a rolling load correction term whose parameter is the ratio of the peripheral speed of the low-speed rolling roll and the peripheral speed of the high-speed rolling roll. , the thickness of the given rolled material,
A setup method for different circumferential speed rolling control, characterized in that the roll opening degree and each roll circumferential speed at different circumferential speeds are calculated from the sheet thickness after rolling, the target rolling load, and the circumferential speed of each roll, and set to the calculated values.