JPS62179803A - Controlling method for differential speed rolling - Google Patents

Abstract

PURPOSE:To stably operate a differential speed rolling device by using rolling specifications as an input signal, calculating neutral point positions of upper and lower work rolls by taking forward and backward tension into consideration and controlling the same within the contact angle region of the work rolls. CONSTITUTION:A calculator 24 calculates the neutral point positions phiH, phiL of the work rolls 1, 2 on a high speed side and low speed side by differential speed rolling model equations 1-3 from the measured values of the sheet thicknesses and tensions on the inlet side and outlet side and a peripheral speed ratio. The peripheral speed ratio is so commanded as to be corrected by a discrimination part 25 if the two neutral point positions phiH, phiL deviate from the conditions expressed by equations 4. 5. The peripheral speed ratio corrected by a setter 21 is inputted to the calculator 24 and again the two neutral point positions are calculated. Input is made to roll peripheral speed setters 15, 16 to convert the two neutral point positions phiH, phiL to the respective roll peripheral speeds if the two neutral point positions phiH, phiL satisfy the conditions for stable rolling.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a control method for a different speed rolling device, and relates to a method for controlling a different speed rolling device, which is suitable for performing stable rolling in %%.

[Conventional technology]

In the rolling of metal plates, a new rolling method that uses young fruit for rolling ultra-thin plates and difficult-to-process materials, and reducing rolling force for the purpose of energy saving, involves rolling by rotating the upper and lower work rolls at different circumferential speeds. A different speed rolling method has been proposed.

In addition to the above-mentioned patents, various proposals have been made for controlling the rotation speeds of upper and lower rolls to a predetermined circumferential speed ratio in the different speed rolling method (for example, Japanese Patent Laid-Open No. 59-229223). Furthermore, in rolling, it is important for stable operation that the points between the upper and lower rolls be within the rolling contact arc.

Conventional control is based on the premise of constant speed rolling, so the deviation of one neutral point to the entry side of the rolling contact arc cannot occur after one sheet is passed. Therefore, by monitoring the advance rate, it is possible to determine whether the neutral point of both wheels has deviated to the exit side of the rolling contact arc, and as a control that takes the neutral point position into account, it is possible to There are known methods in which the neutral point position is calculated by fixing the work roll signal fi11, and there is also a known example in which the neutral point position is brought closer to a specific position under the maximum torque constraint (t\! Publication No. 58-42761)
.

[Problem that the invention seeks to solve]

However, it is not recognized that the one circumferential speed ratio must be controlled using the relationship between the circumferential speed ratio and the neutral point position of the lower roll in consideration of rolling stability in different speed rolling.

Unlike uniform speed rolling, in different speed rolling, one neutral point position may protrude toward the entrance side even after one sheet is passed. At this time, if the other neutral point position is within the rolling contact arc, even if the advance rate of the upper and lower rolls is monitored, it can only be determined that the neutral point of one of the rolls has not protruded to the exit side of the rolling contact arc, resulting in stable It is erroneously determined that it is a rolling process. Therefore, there is a possibility that stable rolling cannot be performed only by monitoring the advance rate. In addition, the neutral point position is subject to fluctuations in parameters such as tension and plate thickness around 1.

Always on the move. In addition, the board speed and roll ducking speed only confirm that the neutral point position is within the limits, and it was also necessary to set a constraint on the maximum torque. The neutral point position is monitored by measuring the front and rear tension, the circumferential speed of the work roll for both plate thicknesses, and calculating the neutral point position.
It has not been known to monitor whether the neutral point position is within limits by calculating the neutral point position even if the neutral point position moves during control during rolling.

An object of the present invention is to monitor the neutral points of the upper and lower work rolls using the relationship between the rolling specifications and the neutral points of the upper and lower rolls in a different speed rolling equipment, and to achieve stable rolling equipment through good control of the neutral points of the upper and lower work rolls. Our goal is to provide the best rolling possible.

[Means for solving problems]

The above purpose is to model the relationship between rolling specifications and the neutral point positions of the upper and lower rolls in a different speed rolling device.

This is achieved by controlling the neutral point using the model. More specifically, the input signals are the input and exit side plates of the different speed rolling equipment, the front and rear tensions, and the work roll speed, and the input signals are used to control the high-speed side work roll and low-speed side work using the U-speed rolling model. Calculate the neutral point position of the roll,
The purpose is to monitor whether or not the calculated neutral point position is within the work roll contact angle area, and adjust the neutral point position to 1tll# so that the neutral point position does not exceed the contact angle area.

[Effect]

Using the rolling specifications as an input signal, the neutral point position is calculated using a model taking front and rear tensions into consideration, and neutral point control is performed so that the neutral point position does not protrude from the contact angle area.

〔Example〕

The present invention will be described in detail using the drawings. First, I will explain the basics.

Figure 2 shows that in a certain rolling schedule, within the rolling contact arc, that is, when the upper roll contact angle θL is between O (exit) and the total contact angle θm (inlet), the distribution of rolling load P changes to the circumferential speed ratio Gy. FIG. 3 is a characteristic diagram showing how it changes depending on The peripheral speed ratio Gv is.

It is expressed as the ratio of the high-speed side roll circumferential speed to the low-speed side roll circumferential speed.

In FIG. 2, the curve of one peripheral speed ratio Gv=αo=l shows the characteristics of constant speed rolling. In constant speed rolling, the upper and lower neutral point positions are symmetrical across the rolled material, so if θL is used, the upper and lower neutral point contact angles become equal.

The pressure distribution is distributed in a triangular shape with the maximum value at the position of the neutral point contact angle φ0 such as one constant velocity rolling.

In FIG. 2, the curve of circumferential speed ratio Gv=α鵞〉1 shows the characteristics of different speed rolling. In different speed rolling, the high speed side neutral point moves to the rolling exit side and the low speed side neutral point moves to the rolling entrance side from the neutral point position during constant speed rolling.

The low-speed side and high-speed side neutral point positions I11 are represented by φL and φH, respectively. The amount of movement at this time is expressed as low speed side and high speed side neutral point movement amounts ΔφL and Δφn using the angle from the neutral point contact angle φG during constant speed rolling.1. The pressure distribution becomes trapezoidal.

In each area, equations for horizontal and vertical balance,
From the yield condition equation, etc., the following distributed load equation for the different speed rolling model can be derived. At this time, C A C
I CCφ1 φL is an unknown quantity.

Pi = Ca e ”“mu” fA (θL) (0≦θL≦
φN >-(1)py+=cme"al16L-fII
(θLl (φ cap ≦ θL ≦ φL) ”・(2) Pc =
Cc e ””' f c (θL) (φL≦θL
≦θ, )−(3) Furthermore, under the continuity condition θL=φH at the neutral point position, PA(φ1)=Pafφ! ()θ, =φ
Considering the relationship between Pm (φLl=PC(φL)) at L, the volume velocity at the neutral point position, the entrance conditions and exit conditions of the rolling region, and from these, the unknowns Ca, Cm of equations (1) to (3),
Cc neutral point position φ■.

Calculate φL.

Using the above model, the neutral point positions of the high-speed side and low-speed side work rolls can be calculated. This monitors the neutral point position.

When both of the neutral point positions are within the range of the total contact angle of the work rolls on the respective corresponding sides, stable rolling can be performed. For this reason, while monitoring the neutral point position, if either side deviates from the corresponding total contact angle area, modify the rolling specifications such as the circumferential speed ratio, and change the direction to ensure stable rolling. It is conceivable to correct the neutral point position.

Using the above-mentioned model, it is possible to set a modification of the rolling specifications, thereby controlling the vaginal neutral point position.

Hereinafter, one embodiment of the present invention will be described with reference to FIG. 1st
The figure is a flow diagram for explaining a method of calculating the neutral point. Figure 1 shows the unknowns φL, φH, in equations (1) to (3),
CAI CIl CO is calculated using input side, output side conditions, continuity conditions, etc. The input is.

Inlet and outlet plate thickness H, h, tension “bH”! *Lishu staff
Tan*kW Knee m-pa great H=Qv -Ok radius R
1,.

R■ etc.

The relationship between the flat roll radius R/Le R'a and the rolling force P can be determined by substituting the obtained rolling force into Hitchcock's equation and calculating R1,
Find the value and compare it with the previous RL value.

A convergence calculation is being performed (if the convergence value from the previous calculation is set as the initial value of Rt,', RM', the calculation time until convergence will be shortened).

When converged, it means that the determined neutral points φL and φH satisfy the rolling conditions. If the limiting conditions are no longer satisfied on the way, the planned neutral points φL, φ■
This means that the rolling conditions are not met.

There are other ways to calculate both neutral point positions, such as the one described above (
Possible methods include analytically solving equations 1) to (3) and deriving approximate equations. For example, when the rolling specifications are constant and the peripheral speed ratio Gv is changed, the neutral point movement amount can be approximated as follows.

What is the relationship between circumferential speed ratio Gv and neutral point movement amount ΔφL, ΔφH?
Consider expressing it as a function of Gy. By function approximation, it can be expressed as, for example, the following formula.

Δφt, =b@Gv"+bIGv"-"t-・+bI
Gv"-'+=+b,.

・・・・・・・・・(4) ΔφH= CQ Gv "10 CI Gv"-' 10...
・+ CI Gv"-'+ ...+ c.

・・・・・・・・・(5) b, = f φ L (G1.
h, tt, tb, μshi, μ
H... )...(6)c,=fφn (H+ J
"tr tb, aLr μn=・F・(71n
: Order of approximation! Integer from 20 to n, c: A function of the rolling schedule, such as plate thickness, tension, friction coefficient, etc., which becomes a constant when the rolling schedule is given, and Gv in equations (4) and (5).

It becomes the coefficient of the term.

H Plate thickness on the two-person side h: Output side plate thickness tr: Output side unit tension tb: Inlet side unit tension μL: Low speed side roll friction coefficient Iyu: High speed side roll friction coefficient (4) to (7) when moving in Gv Used as a model formula.

Next, at a certain peripheral speed ratio Gv, the vertical neutral point position φL,
It is necessary to check whether φU is within the rolling contact arc.

These can be expressed as linear using neutral point shift @ amounts ΔφL and ΔφH.

θ1−φ0〉ΔφL＞O・・・・・・・・・(8)φ,
〉ΔφR＞Q ・・・・・・・・・(9)(
8) An application example of the present invention is shown in FIG. 3, in which the formula (9) is used to check the rolling conditions at the time of Gv normalization.

The calculator 24 calculates two neutral point positions from the measured values of the plate thickness and tension on the inlet and outlet sides, and the circumferential speed ratio. That is, (
The unknown quantity CA CI CCφLφH in equations 1) to (3) is determined from the continuity condition at the neutral point, etc.

In the Ptl constant section 25, if the two neutral point positions deviate from the conditions for stable rolling (conditions of equations (8) and (9)), a command is given to correct the one-periphery speed ratio. Setting device 21
The circumferential speed ratio corrected by is input to the calculator 24, and the two neutral point positions are calculated again.

If the two neutral point positions satisfy the conditions for stable rolling, the two neutral point positions are set by the roll circumferential speed setting device 15.1.
Enter 6.

The roll circumferential speed setter 15, 16 converts the two neutral point positions into respective roll circumferential speeds based on the command value of the outlet plate speed.

In the embodiment shown in FIG. 3, each value is determined as follows, but it goes without saying that other methods can also be used.

The plate thickness is determined by the load meter 6 attached to the backing roll 3 and the roll gap detector 7 attached to the backing roll 4.
The rolling load P and roll gap S are detected respectively. The calculator 20 calculates the exit side plate I of the rolled material 5 from these inputs using the well-known Hooke's law. In other words: Mill rigidity coefficient The plate thickness on the inlet side is a value obtained by delaying the plate thickness on the outlet side of the preceding rolling device by the time of movement of the pressurized abrasive material 5.

The tension is detected by a tension gauge 8 provided on the entry side of the material 5 to be rolled. Tension control device 9 converts tension into plate speed.

To set the roll circumferential speed, the roll circumferential speeds from the neutral point on the low speed side and the high speed side and the control board speed are set in the respective roll speed control devices 113.14 output by the roll circumferential speed setting device 15.16. .

Note that (4) and (5) can be used as a method for the calculator 24 to calculate the two neutral point positions from the measured values of the board thickness and tension on the entry side and the exit side, and the circumferential speed ratio.

At this time, the determination unit 25 uses equations (8) and (9). During different speed rolling at a certain constant circumferential speed ratio, deviations can be stably suppressed by controlling the circumferential speed ratio.

〔Effect of the invention〕

According to the present invention, the neutral point positions of the upper and lower work rolls can be monitored and the neutral point can be favorably controlled, and stable different speed rolling can be realized.

[Brief explanation of drawings]

Fig. 1 is a diagram showing an example of a method for calculating the neutral point position, Fig. 2 is a characteristic diagram showing the relationship between contact angle and distributed load, and Fig. 3 is a control method for a variable speed rolling device according to the present invention. It is a figure showing an example of application. l...Upper work roll, 2...Lower work roll, 3.4
... Back roll, 5... Rolled material, 6... Weight gauge,
7...O-le gap, feeding device, 8...Tension meter, 9...Tension control device, 13.14...Speed control device, 24...Rolling finish (from the child to both neutral point positions 25... Judgment unit for determining whether both neutral point positions satisfy concentration, 15.16... Roll circumferential speed setting device, 21... Peripheral speed ratio setting device.

Claims (1)

[Claims] 1. A system comprising a pair of work rolls, a pair of drive devices that pivot each work roll at a predetermined circumferential speed ratio, and a speed control device that controls each drive device to a set speed. In a method for controlling high-speed rolling equipment, input and exit plate thicknesses, front and rear tensions, and work roll speeds of the different-speed rolling equipment are used as input signals, and the input signals are used to control the high-speed side work roll and the work roll by a different-speed rolling model. Calculates the neutral point position of the low-speed work roll, monitors whether the calculated neutral point position is within the work roll contact angle area, and prevents the neutral point position from protruding from the contact angle area. A control method for different speed rolling characterized by controlling a neutral point position. 2. Different speed rolling characterized in that a model derived from the relationship between plastic deformation of the rolled material and roll speed of the rolling mill is used as a model for calculating the neutral point position as set forth in claim 1. control method. 3. As a model for calculating the neutral point position according to claim 1, the difference between the total rolling force when the upper and lower roll speeds are constant and the total rolling force when the upper and lower rolls are at different speeds, and each of the upper and lower rolls. 1. A control method for different speed rolling, characterized in that the relationship between the neutral point position and the amount of movement from the time of constant speed is used as a model. 4. In monitoring the neutral point position according to claim 1, the neutral point position calculated by the model is calculated based on the distance from the roll exit of the rolled material, and the neutral point distance is a positive value and A method for controlling different speed rolling, characterized in that it is determined to be normal when the length is shorter than the roll contact length. 5. A method for controlling different speed rolling, characterized in that in the control of the neutral point position according to claim 1, the command of the speed control device is changed in proportion to the amount of change in the neutral point position. . 6. A method for controlling different speed rolling, characterized in that in the control of the neutral point position as set forth in claim 1, command values for the front and rear tensions are changed in accordance with the amount of change in the neutral point position. . 7. A method for controlling different speed rolling, characterized in that in controlling the neutral point position as set forth in claim 1, the target value of the outlet plate thickness is changed in accordance with the amount of change in the neutral point position. .