JPS5961517A - Method for automatically controlling sheet thickness in rolling mill - Google Patents

Abstract

PURPOSE:To keep the sheet thickness at the outlet side of a mill constant in accordance with the thickness deviation of a sheet to be rolled by feeding separately a coolant to upper and lower rolls, and controlling the flow rate or the concentration of the coolant to produce the difference between the peripheral speeds of respective rolls. CONSTITUTION:Coolant sprayers 9 are separately arranged at the inlet side of rolls 8 having equal peripheral speeds each, and the signal of a thickness gauge 10 is inputted to a time-delay computing element 4- a coolant flow rate, concentration arithmetic unit 5. Next, the calculated results DELTAX11, DELTAX12 or DELTAX21, DELTAX22 obtained by using the following equations, DELTAV'1+DELTAV'2=2DELTAH1V1/H2 (H1, H2; the sheet thicknesses at the inlet side and the outlet one of a rolling material, V1, V'1, V'2; speed of rolling material at the inlet side, speeds of rolling material at the outlet side of the upper and lower rolls) V'1=f5(X11, X21), V'2=f6(X12, X22) (X11, X12; the flow rate of each coolant, X21, X22; the concentration of the same), are outputted to produce the difference between above mentioned V'1, V'2, by regulating the flow rate or the concentration of the coolant sprayed by the sprayers 9. Thus, the sheet thickness at the outlet side of a mill is kept constant in accordance with the change of the sheet thickness at the inlet side.

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention relates to an automatic plate thickness side Ul method for a rolling mill that separately controls the amount or concentration of roll coolant sprayed onto an upper work roll and a lower work roll. It is.

[Technical background of the invention]

In conventional rolling mills, the circumferential speed of a pair of upper and lower work rolls (hereinafter referred to as upper and lower rolls) is the same, and the same amount of roll coolant is sprayed on the upper and lower rolls, so that the
Rolling has been carried out with the friction conditions between 770 and 770 being the same, and the N:friction coefficient being the same.

However, in recent years, so-called Pv rolling has been devised in which the circumferential speed of the upper roll and lower roll is different.It has advantages such as the ability to perform strong rolling by reducing the rolling force by 1, reducing edge drops, and lowering the rolling limit. It has been adopted by many rolling mills.

[Problems with background technology]

In normal PV rolling, it is assumed that the rolls are driven individually for the upper and lower rolls, and this is not possible in a rolling mill with a common drive for the upper and lower rolls. In addition, even in the case of an individually driven rolling mill, the drive system requires major modification or modification, which is disadvantageous economically.

[Purpose of the invention]

The present invention was made in consideration of the above-mentioned circumstances, and regardless of whether the upper and lower rolls are driven individually or H1 rolling with a common drive system, it is possible to achieve the same effect as the PV rolling method, and it is possible to achieve the same effect as the PV rolling method. Automatic plate thickness control for rolling mill that is economical and does not require modification of the drive unit, and keeps the output f and lI plate thickness constant even if the input plate thickness changes 1
The purpose is to provide a method.

[Summary of the invention]

In order to achieve the above object, the present invention separately supplies the upper and lower rolls with the amount of roll coolant or the concentration of the roll coolant (tfill If)11 to obtain the same effect as the Pv pressure processing force θ2. This is a method that allows you to

[Embodiments of the invention]

Hereinafter, the automatic plate thickness control method according to the present invention will be explained with reference to the drawings. FIG. 1 shows the state of contact between the upper and lower rolls 1 and the strip 2 during rolling. Here, Vl is the rolling mill side speed, I1 is the angle from the material exit point of the neutral point position on the roll contact arc between the upper roll and the rolled material, and I2 is the neutral position on the roll contact arc between the lower roll and the rolled material. The angle of the point position from the rolling material outlet point, V.

represents the circumferential speed of the upper and lower rolls, V, / represents the exit speed of the rolled material on the upper roll side, and 2' represents the exit speed of the rolled material on the lower roll side. Here, arrow 3 indicates the direction of the frictional force on the roll contact arc. Now, if the friction coefficient between the upper roll and the strip is μ and the friction coefficient between the lower roll and the strip is I2, then the following formula holds true.

μm ”” f 1 (XB r X21 )
-(1) I2 ""f2 (XI21 X22)
...(2) However, Xll is the upper roll coolant flow rate X21, the lower roll coolant concentration XH2 is the lower roll coolant flow rate X2, and φ,'=f, (μI) ...(3) I
2-f4 (/j2)...(4) Generally, when the roll coolant flow rate X11+XI2 increases, the friction coefficient μm, I2 decreases, and the neutral point ht
Angle φ, from the feed point of the position.

I2 increases 2. The neutral point moves to Rollbite Naijinsen 1. As a result, rolling 4: advancement rate F of the upper and lower surfaces of the spines
,,F2 increases and the old extrusion speed v1.

V2 increases. Therefore, the following formula stands at 5ν.

V+ = f5 (Xll l X21)...
(5) V2 = fa (XI2 1 X22)
-(6) Coolant flow fi-xlI as shown in equations (5) and (6).

X1□ also [2〈is I1 if the coolant concentration X21+X22 is controlled individually for the upper roll and lower roll.

I2 changes, and rolling similar to PV rolling becomes possible.

Figure 2 1 (Bamboo-Lant rumors, controlling coolant concentration 01
11 shows a conceptual diagram of the system. 4 i-J: time delay calculator, 5 is coolant flow rate concentration operation/Jl- device, 6 is upper roll coolant flow rate concentration side device, 7 is lower roll coolant flow rate concentration side (incorporated) device, 8 is upper and lower 9 is a roll coolant spray device, and 10 is a thickness gauge on the rolling mill side.

Now, the speed and plate thickness at the entrance and exit sides of the roll bite are HIVi = H2 (V1' + Vz') / 2 - + (there is a force relationship, so even if the input side thickness of the rolled material changes, the exit side plate thickness In order to keep v,', v2' constant, ΔV,'-
1-ΔV2' = 2ΔH+ V+ / H2-(8)
All you have to do is change it so that it satisfies the following. One size (5).

From formula (6), when performing M1 on the roll coolant flow rate side, ΔX77. ΔX12% When suppressing roll coolant concentration, set ΔX12. All you have to do is operate ΔX22. Thickness total 1
The output signal ΔH from 0 is calculated by the time delay calculator 4 from the detection point of the thickness gauge 10 to the stand). After compensating for the time delay, the above (
8) Using equations (5) and (6), coolant flow rate concentration calculation device 5. J: SuΔX11. ΔXI2 or ΔX2+)
Apply ΔX22 to IB and roll coolant spray device 9.
By controlling the sprayed coolant flow side or the coolant concentration, the strip thickness at the exit side of the rolling mill can be kept constant.

PV even with normal upper roll, lower roll 1, and reverse drive rolling mill
By using the present invention in conjunction with a Pv rolling mill that performs rolling at different circumferential speeds in a rolling mill in which the upper roll and lower roll are individually driven, the rolling This helps reduce the force and prevents errors due to a decrease in edge drop, which lowers the rolling limit.

Therefore.

By making it possible to roll the plate approximately in thickness, and by making strong reduction possible, the number of passes can be reduced, and if intermediate annealing is required, the number of times can be reduced, and by reducing the rolling force, energy savings can be achieved. It also has a ghee effect and can extend the life of the roll.

〔Effect of the invention〕

As mentioned above, the present invention can perform automatic plate thickness auxiliary gearing by rolling equivalent to PV rolling, regardless of whether the ten rolls and lower rolls are driven individually or in common. Automatic plate thickness determination for rolling mills that is cost-effective and economical
I can provide a method.

[Brief explanation of the drawing]

Figure 1 is a diagram for explaining the automatic plate thickness sterilization method of the present invention, and is a diagram showing the swing angle of the strip and roll in the first state;
The figure is a diagram for explaining the concept of the coolant system d1 used in the present invention. l...work roll, 2...strip, 3...
Direction of frictional force, 4... Time delay calculator, 5... Coolant flow fi (concentration calculator 6... Roll coolant flow rate concentration secondary tooth 1 device, 7... Lower roll coolant flow rate concentration secondary Equipment, 8... Rolling roll, 9... Roll coolant spray device, 10... Machining, milling.

Claims (2)

[Claims] (1) In a rolling mill where the circumferential speed of the upper and lower work rolls is illusory, the upper work roll and lower work roll (prefix) and IJ
The flow force or the concentration of the roll coolant that is sprayed individually between the tubes is controlled according to the deviation between the target rolled plate thickness and the actual rolled thickness. Fill L, the circumferential speed of the upper work roll and the lower work roll A method of automatic plate thickness control in a rolling mill that allows for a difference in thickness. (2) In a rolling mill where the circumferential speeds of the upper and lower work rolls are different,
The flow of the roll coolant sprayed individually between the one work roll and the lower work roll and the strip or its concentration is controlled according to the deviation between the target rolled plate thickness and the actual rolled thickness. L. Automatic plate thickness of a rolling mill that further increases the difference in circumferential speed between the upper work roll and the lower work roll: 1ill (Incorporated) method.