JPH01317620A - Control method for roll leveier - Google Patents

Abstract

PURPOSE:To improve the straightening accuracy for a steel plate by controlling a difference to power of the remaining driving motor so as to go to a prescribed value, with respect to power in the course of straightening of the motor concerned, based on one piece of driving motors as a reference, controlling the tension between plural rolls of the roll reveler to a prescribed value. CONSTITUTION:The rolling reduction T required at the time of straightening a roll leveler 21 is calculated in advance in accordance with a material condition of a steel plate S to be straightened by a host computer 27, and its value is sent into a subordinate computer 26. In the computer concerned 26, a roll gap of the leveler 21 is set to a prescribed position, respectively through a leveler rolling reduction controller 25. Simultaneously, a peripheral velocity of the roller is controlled through a motor side controller 23 and set to a prescribed steel plate speed. Subsequently, the steel plate S is brought to strip passing, and as soon as straightening is started in the leveler 21, a power signal of a driving motor M2 of the second roll group B is inputted in the computer 26, calculated and power of the driving motor M1 of the first roll group A is controlled, and while setting the tension between both the roll groups A, B to a prescribed value, straightening is executed.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a method for controlling a roller leveler, and in particular, a method for correcting a steel plate with poor flatness after rolling using a roller leveler, and finishing it into a flat steel plate without distortion. This invention relates to a control method suitable for.

<Prior art> Normally rolled steel plates suffer from loss of flatness or warp in the longitudinal or width direction due to various conditions during rolling or during the cooling process. As equipment for this purpose, there is a roller leveler that uses repeated bending and has multiple rollers arranged in a staggered manner.

However, when straightening a steel plate using such a roller leveler, it is known that it is difficult to correct distortion when straightening a steel plate whose thickness is thin compared to the roll pitch. The tensilon correction method is used to add tension to the This tension correction is commonly used for thin plates, but in recent years it has also been adopted in thick plate equipment.

Basically, as shown in Fig. 4, the method of applying tension in tension correction is to use a plurality of rolls 1 to 1.
For example, the drive system of No. 2 is divided into two, and the first drive motor gate 7.
The second drive motor h is used to provide a speed difference between the first roll group A and the second roll group B, thereby applying tension to the steel plate S and controlling it.

Various means can be considered as a control method at this time, but for example, as disclosed in Japanese Patent Application Laid-Open No. 58-84614, the material is Methods of generating axial force, and
As disclosed in Japanese Patent Application Laid-Open No. 60-223615, the axial force generated between each roll group is detected, and the leveler reduction amount, roll circumferential speed, or Methods for adjusting the two have been proposed.

<Problems to be Solved by the Invention> However, in the former method of JP-A-58-84614, even though tension is applied to the material to be straightened, it is difficult to control the predetermined tension itself, so it is difficult to completely control the tension itself. It's not a perfect solution.

Furthermore, the latter method disclosed in Japanese Patent Application Laid-Open No. 60-223615 requires the installation of a tension detector, resulting in problems such as relatively high equipment costs.

An object of the present invention is to provide a roller leveler control iTJ method that solves the above-mentioned problems.

<i! l! Means for Solving the Problem> The present invention provides a roller leveler control method in which a plurality of rolls arranged in a staggered manner are divided into two or more groups, and the speed of each group is controlled by an individual drive motor.
Control of a roller leveler characterized in that, with one of the drive motors as a reference, the difference between the power of this drive motor during straightening and the power of the remaining drive motors is controlled to a predetermined value. It's a method.

For Kusaku The principle of the present invention will be explained below.

Figures 2 and 3 show the load F (kg) applied to the steel plate S of each roll in the roller leveler with the 12 roll arrangement shown in Figure 4 above and the plate feeding force μ・F ( k
g) (where μ is the coefficient of friction between the roll and the steel plate), and the effect of the tension T (kgf/mj) between the first roll group A and the second roll group B caused by speed difference control. This is a schematic representation of each sub-plate.

Now, in the first and second roll groups A and B, the amount of work done by the rolls applied to the steel plate S per unit time E□+
ElmsAlso, the amount of work done per unit time by the tension T on the steel plate S! t, the bending work per unit time acting on the steel plate S is f E M a.

From the energy balance point of view, E□ is as follows (1), (2
) holds true.

E, 1a-E*h+By...
Song・-Song (1) UNI San E□-E7
- Curve 4 - (2) Here, if the steel plate speed (-roll circumferential speed) is V (+s/m), the amount of work done by the first roll per unit time I! s1 is expressed by the following formula (3).

E31 Massage ■ μiFi (kgfs/m)
・−・−・・−・−・ (3) Therefore, the amount of work I per unit time performed by the rolls applied to the steel plate S in the first and second roll groups A and H! marEll is represented by the following formulas (4) and (5), respectively.

Also, the amount of work done by the tension T on the steel plate S per unit time [! 7 is expressed by the following formula (6).

[! v-V・T (kgfs/master)
・−・−−・・−・ (6) On the other hand, the bending work ff1L+i per unit time of the first roll acting on the steel plate S is expressed by the following equation (7).

σ,! EMI--・b-h-V-ksr (kgfm/m
)1・・・・−・−・(7) Here, σy: Yield stress of steel plate (kgf/c+1)
Young's modulus of E8 steel plate b: Width of steel plate (m+*) h: Thickness of steel plate (m) ksr j Coefficient determined by the degree of bending of the steel plate.

−(1−αi)”/αi (αi is the ratio to the yield strain of the steel plate surface) Therefore, the bending work per unit time acting on the steel plate S in the first and second roller groups A and B is HMA+
[MI is represented by the following formulas (8) and (9), respectively.

4 σ, 1 ・−・−・−・・ (8) ・−・・・・−・−・ (9) Next, the power per unit time of the drive motor H8 of the first roll group A is expressed as PHI Ckgt 1/m), and the power per unit time of the drive motor h of the second roll group B is P.
Ht Ckgfta7m), then P 111 =
E sa ・---=-0
[1) PMl=E! l・−
...-00, the above equations (1) and (2) are respectively expressed by the following 021°03 equations.

[1na=Px+ + T−V −−
−−・−Q21E, =P+<z T−V
---------OmHere, if we add Oz and the zero-match formula and rearrange it, we get 04).

EX^+ENI EPIA + EMI Substituting these 04) and 05) formulas into the side formulas,
By subtracting and rearranging, the following 0ω formula is obtained.

・・・・・・−OQ Therefore, while controlling the roll circumferential speed of the second roll group B using the second drive motor and adjusting the steel plate speed V, the power P□ is calculated using the above OQ formula. By controlling the power P, ll of the first drive motor M1 that controls the circumferential speed of the rolls of the first roll group A, it is possible to control the tension T applied to the steel plate S to be constant.

In addition, in the above formula 00, the bending work per unit time acting on the steel plate S is ft[! The material properties σ, , E, b, and h of the steel plate S included in gA and EMI are canceled out during the calculation process, leaving only □ as a coefficient determined by the degree of bending of the steel plate, so the above equation 00 is extremely susceptible to external disturbances. This makes it possible to control with high precision.

Furthermore, in the above description, the group of 12 rolls was divided into two and the drive motors were divided into two systems, but the present invention is not limited to this, and the drive motors may be divided into three or more systems, or the rollers may be driven by three or more systems. The control concept is the same even if the number is not 12.

<Example> Below, an example of the present invention will be described in detail with reference to FIG.

FIG. 1 is a block diagram showing a control device suitable for carrying out the method of the present invention.

In the figure, 21 is a roller leveler consisting of 13 rolls, divided into two groups: a first roll group A of 4 rolls and a second roll group B of 9 rolls, each of which is rotationally driven by a drive motor MI+ Mt. be done.

Reference numeral 22 denotes a rotation detector such as a pulse generator, which is attached to the rotation shaft of the drive motors M+ and Hz, respectively, and detects the rotation speed of the drive motors M, . . . MZ.

23 is a motor control device that controls the drive motor;
The rotational speed of each drive motor M+5Mz is controlled. Note that a rotation speed detection signal from the rotation detector 22 is input.

Reference numeral 24 denotes a leveler lowering device of the roller leveler 21, which controls each roll to a predetermined position based on a control signal from a leveler lowering control device 25.

2G is a lower-level computer that performs seed calculations based on information necessary for correction from the higher-level computer 27, and
3. It has a direct digital control (DDC) function that outputs commands to the reduction control device 25, respectively.

The operation of the control device configured in this way will be explained below.

First, the host computer 27 calculates in advance the reduction amount and optimum tension l (T) necessary for straightening the roller leveler 21 according to the material conditions of the steel plate S to be straightened, and
6) Expression [! HA/[8□(E, A + E□)/I
! The values of sm and T are sent to the lower-order computer 16 as command signals.

In the lower calculation a26, the roll gap of the roller leveler 21 is set to a predetermined position via the leveler reduction control device 25, and the peripheral speed of the roll is controlled via the motor control device 23 to a predetermined steel plate speed (V). Set.

At the same time as the steel plate S is threaded and straightening is started in the roller leveler 21, the lower computer 26 takes in the power signal (P□) of the drive motor h of the second roll group B and calculates the power signal of the drive motor h of the second roll group B. The power of drive motor A of A (PH1
) to control the first roll group A and the second roll group B4.
Correct the tension by setting the tension between the two to a predetermined value.

<Effects of the Invention> As explained above, according to the present invention, by introducing the energy balance concept, it is possible to control the tension between the plurality of roll groups of the roller leveler to a predetermined value, so that the steel plate Improves correction accuracy and contributes to quality improvement.

Furthermore, since there is no need to install a tension detector or the like, equipment costs can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing a control device suitable for implementing the method of the present invention, FIG. 2 is an explanatory diagram schematically showing the effects of load and torque applied to a steel plate, and FIG. FIG. 4 is an explanatory diagram schematically showing the action of the tensilon between the first roll group and the second roll group, and is a schematic configuration diagram of a conventional roller leveler. 21... Laura Leveler. 22... Rotation detector. 23...Morph control n device. 24... Leveler lowering device. 25... Leveler pressure reduction control device. 26...Lower computer. 27...High-level computer. Ml L...Drive motor. S...Steel plate. T...Tension. PHi, P□...Drive motor power. ■・・・Steel plate speed. Patent applicant: Kawasaki Steel Corporation Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] In a roller leveler control method in which a plurality of rolls arranged in a staggered manner are divided into two or more groups and the speed of each group is controlled by an individual drive motor, the drive A method for controlling a roller leveler, comprising controlling the difference between the power of the motor during straightening and the power of the remaining drive motors to a predetermined value.