JPH0124566B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a variable lateral stiffness control device for a rolling mill.

The lateral rigidity of a rolling mill is a concept that expresses the amount of deflection in the roll width direction due to rolling force, and is defined by the formula: Q=rolling force/plate crown Ton/mm.

As shown in Fig. 1, the lateral stiffness Q of this rolling mill changes depending on the strip width, and the bending effect coefficient K _B also changes depending on _the strip width. It is difficult to appropriately determine the relationship between bending force P and _B.

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. 2a, the rolling force increases (P _R1
→P _R2 ), if the lateral stiffness is kept high from Q ₁ →Q ₂ , it is possible to roll with a constant crown ratio. In addition, as shown in Figure 2b, the heat crown
For C _H , if the lateral stiffness is lowered from Q ₁ → Q ₃ ,
Rolling can be done with a constant crown ratio. Furthermore, when rolling the entrance plate crown zero, if the lateral stiffness is made infinite from Q → Q _∞ as shown in Figure 2c,
Decrease bending d is required to cope with the heat crown C _H , which may not be practical, but even in this case, if the rolling mill is given an appropriate lateral stiffness (for example, Q ₃ ), the range of increase bending can be reduced. It is possible to control the plate crown with respect to the heat crown within the rolling stock, making it easy to roll a plate with a flat crown shape.

Conventionally, as one means for variably controlling the lateral rigidity of a rolling mill, it has been considered to vary the contact width between a work roll and a plate, and the contact width between a backing roll and a work roll. As one of the measures, it has already been announced that the horizontal position of the upper and lower intermediate rolls of a 6-high rolling mill should be kept at a certain ratio to the strip width (Japanese Patent Application Laid-Open No. 49-1999-
41255, Japanese Patent Publication No. 1983-30777, Special Publication No. 1987-19510). However, in this case, if the contact width between the backing roll and the work roll changes, the vertical rigidity, which is originally important in a rolling mill, changes significantly, so there is a drawback that the plate thickness accuracy is adversely affected.

The present invention provides a lateral stiffness control method that allows the lateral stiffness of a rolling mill to be kept uniform without being affected by the strip width, and that allows only the lateral stiffness to be controlled without affecting the vertical stiffness. This was done in order to provide the equipment.

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.

Cr＝P _R ／Q−{C ^* ＋P _B ／K _B } ...(1) C ^* ＝C _H −C _W ＋C _I Q; Lateral rigidity (Ton/mm) P _R ; Rolling force (Ton) Cr; Output side plate crown (mm) C _W ; Roll wear (mm) C _I ; Initial crown (mm) P _B ; Roll bending force (Ton) K _B ; Bending effect coefficient (Ton/mm) From the above formula, the output It can be seen that the side plate crown Cr is determined by the lateral rigidity of the rolling mill, rolling force, roll shape, roll bending force, etc.

In the above, the roll bending force P _B is expressed by the following formula.

P _B =CK _B /QP _R (2) Substitute this roll bending force P _B into equation (1).

Cr=(1-C)/QP _R -C ^* ...(3) =P _R /Q/(1-C)-C ^* =P _R /Qe-C ^* ...(4) Qe=Q/1 -C...(5) By controlling in this way, a controlled equivalent lateral stiffness Qe can be obtained.

In the above formula, C represents the lateral stiffness control coefficient. When C=1, Qe=∞ When C=0, Qe=Q When C=-∞, Qe=0 As a result, arbitrary lateral stiffness can be given.

Further, in the above equation (2), K _B /Q indicates the ratio of bending force that corrects the deflection of the roll due to the rolling force, and an example of this is shown in FIG. In this case, since the strip width is known before rolling, the value of K _B /Q is selected according to this width, and the lateral stiffness control coefficient C is set to an appropriate value according to the rolling conditions. Roll it. By doing the above, the lateral stiffness can be controlled to the most appropriate value depending on the board width. Further, the lateral rigidity can be controlled to be constant regardless of the plate width.

When a lateral stiffness control device is constructed based on the above principle, it becomes as shown in FIG.

FIG. 4 shows a first embodiment of the present invention, 1, 2
is a work roll, 3 and 4 are backing rolls, and 5 is a plate. An increase bender 6 is provided between the axle boxes of work rolls 3 and 4, and between the axle boxes of work rolls 1 and 2 and the backing roll 3, A decrease bender 7 is provided between the axle box 4 and the work rolls 1 and 2 to be bent into a concave or convex curve by applying hydraulic pressure to each of the work rolls 1 and 2. This bending pressure is detected by pressure transducers 8 and 9, and the difference is calculated and fed back by an amplifier 10, and the servo amplifier 11
, and a gain of 12 is given so that it can be controlled by a servo valve 13.

On the other hand, the rolling force P _R is detected by the load cell 14,
It becomes the roll bending force P _B through the lateral stiffness coefficient setter 15 and the function unit 16, and is output to the summing amplifier 1.
7 is input. The function device 16 has a board width setting device 18.
A function K _B /Q (third
(see figure) is given, and the lateral stiffness coefficient setter 15
A constant lateral stiffness coefficient C is set for the servo amplifier 11, and these are operated in relation to each other so that the optimum gain 12 is outputted from the servo amplifier 11. Setting of the roll bending force from the outside is performed by an initial setting device 19.

In the figure, 20 indicates a housing, and 21 indicates a hydraulic pump.

FIG. 5 shows a second embodiment of the present invention in which a variable surface profile roll ( _VC roll) is used as the backing roll.

The backup rolls 3a and 4a have a hydraulic chamber 2 in the center of the roll.
2, and the surface profile can be changed by applying hydraulic pressure to the hydraulic chamber 22, and this surface profile changes (expands or contracts) in proportion to the hydraulic pressure.

When rolling with these backing rolls 3a and 4a incorporated, the initial crown in C ^* in equation (4) is determined based on the relationship given by the backing rolls 3a and 4a, depending on the expected value of rolling force and the strip width. Bending control will be performed.

In this case, plate crown change ΔCr in equation (4)
can be calculated as follows.

ΔCr=ΔP/Qe−ΔC ^* ……(6) ΔC ^* =0 ΔCr=ΔP/Qe ……(7) In other words, give the initial roll crown value to the backup roll, lock on with the appropriate plate crown value, and lock on to that point. Control the lateral stiffness based on The lateral stiffness Qe controlled by this becomes constant regardless of the plate width, and can take any value as shown in FIG. 6 depending on the lateral stiffness coefficient.

Specifically, the signal of the rolling force when the initial crown value is applied to the work rolls 1 and 2 by the backing rolls 3a and 4a is locked on 23 and stored in the storage device 24, and the signal from the load cell 14 and the signal from the above-mentioned The signal from the storage device 24 is compared with the signal from the storage device 24 by a computing unit 25 to determine the difference, and the rolling force is known from the difference signal. Also, backup roll 3
In order to give a predetermined crown to a, 4a, an oil passage 26 is communicated with the hydraulic chamber 22, and a pressure intensifier 2 is connected to the oil passage 26.
7 and a servo valve 28, a servo amplifier 29 for issuing a required signal to the servo valve 28, and a pressure transducer 30 for detecting the oil pressure in the hydraulic chamber 22, the pressure transducer 30
The signal output from the servo amplifier 29 is fed back to the servo amplifier 29 via an amplifier 31, and an initial crown value 32 can be set in the servo amplifier 29 to give an initial crown to the backup rolls 3a, 4a.

In the case where the V _C roll is used as the backing roll as described above, if the increase in the profile diameter of the backing roll with respect to the strip plate width is C _B , then the strip crown Cr
The influence coefficient αv on is αv=Cr/C _B ……(8) _CB = βP _V ……(9). As mentioned above, the hydraulic pressure P _V and the crown roll diameter crown C _B have a proportional relationship, and the coefficient β
is approximated by a function of the square of the plate width. As shown in FIG. 7, the relationship between the plate width and the influence coefficient αv shows a constant value when the hydraulic pressure P _V is constant.

FIG. 8 is a third embodiment of the present invention, and shows an embodiment in which the internal pressure of the holding roll and the bender are controlled in conjunction with each other. The basic idea in this embodiment will be explained below.

When a V _C roll is used as a backing roll, a plate crown of Cr=P _R /Q−{αvβ+P _B /K _B } (10) is given to variations in rolling force.

In this case, the hydraulic pressure P _V of the backing roll is determined by P _V = CP _R /αvβQ, so the plate crown is determined by Cr = (1-C/αvβ)P _R /Q-P _B /K _B. Given.

Here, by varying the P _V value, lateral stiffness control is performed with P _B =0 and Qe = Q/(1-C/αvβ).

However, if the absolute value of the bending amount due to the rolling force is large and exceeds the diameter crown value of the backing roll due to the hydraulic pressure P _V , control is applied to add the bender force while maintaining P _V max, and the lateral Satisfy stiffness control. In other words, this method uses hydraulic pressure
The remainder after subtracting the rolling force converted to the P _V value is given as the bender adjustment amount, which can be expressed by the following formula.

ΔP _R =P _R −P _R c=P _R −(1/CαvβPv) Either correct the ΔP _R obtained in this way with a bender, or calculate P _B0 = K _B αvβPv from the P _B value calculated from the rolling force. It is also possible to subtract the value and use it as the vendor setting value.

Next, a control device using such a system will be explained with reference to FIG. 8. As in the case of FIG. 5, the backing rolls 3a, 4a have a hydraulic chamber 22 in the center of the roll,
The surface profile can be changed by applying hydraulic pressure to the hydraulic chamber 22, and the surface profile changes in proportion to the hydraulic pressure.
This hydraulic pressure (internal pressure) is applied to the servo valve 28 and pressure intensifier 27.
is fed back to the servo amplifier 29 via the pressure transducer 30 and amplifier 31.

On the other hand, the rolling force P _R signal detected by the load cell 14 is transmitted to the first lateral stiffness coefficient setter 15a, K _B /Q
The signal is input to the summing amplifier 17 via a first function unit 16a having a function. Further, the inner pressure setting force P _V of the retaining roll inputted to the servo amplifier 29 is determined by the signal of the rolling force _PR detected by the load cell 14 being input to the second lateral stiffness coefficient setting device 15b,
It is calculated by passing through a second function unit 16b having a function of 1/αvβ. 1st
The function K _B /Q in the function unit 16a and the function 1/αvβ in the second function unit 16b are determined by the plate width, and the plate width value signal from the plate width setting device 18 is The signal is sent to function units 16a and 16b. It also includes a saturation value detector 33 that detects when the internal pressure set value of the backing roll has reached the saturation value, and when the saturation value detector 33 detects the saturation value, the switch 34 is activated and the first function The signal that has passed through the second function unit 16a enters the summing amplifier 17, and the control shown in FIG. amplifier 29
It's starting to come in. This converter 35 is used to subtract the initial crown of the backing rolls 3a, 4a, and has a function K _B αvβ set therein, which also changes depending on the sheet width.

Incidentally, when it is detected that the internal pressure of the backing rolls 3a, 4a has reached the saturation value, the rolling force may be memorized and locked on, and the lateral stiffness control loop may be activated as shown in FIG. Furthermore, control of the internal pressure and control of the bender pressure P _B can be used simultaneously.

In this case, instead of detecting the saturation of the internal pressure, changes in rolling force are controlled by allocating the ratio between the internal pressure and the bender pressure.

In other words, the plate crown is Cr=P _R /Q-C ₁ P _R /αvβQ-C ₂ /QP _RThe lateral stiffness is ∴Qe=Q/(1-C ₁ /αvβ-C ₂ ) ∵P _B =C ₂ K _B /QP _R P _V = C ₁ /αvβQP _R , and the equivalent lateral stiffness can be controlled by giving the ratio of the lateral stiffness coefficients C ₁ and C ₂ .

This block diagram is shown in FIG. 9 as a fourth embodiment of the present invention. In the figure, reference numeral 36 indicates a first lateral stiffness coefficient setting ratio device, and numeral 37 indicates a second lateral stiffness coefficient setting ratio device. Also, Figures 8 and 9
In the figures, the same parts are indicated by the same reference numerals.

Since the present invention has the above-described configuration, it can produce the following excellent effects.

(i) Even if the plate width changes, the lateral stiffness does not change and can be controlled uniformly.

(ii) This controlled lateral stiffness can be set to any value.

(iii) It can be carried out in a 4-high rolling mill, and the contact width between the holding roll and the work roll does not change. Therefore, even if the lateral stiffness is changed, the vertical stiffness does not change, so there is no adverse effect on the plate thickness accuracy.

(iv) Since the control device performs variable lateral stiffness control, the machine can be simplified and manufacturing costs can be reduced.

(v) Compared to the 6-high rolling mill intermediate roll movement method as this type of lateral stiffness variable control method, it has advantages such as fewer rolls, less wear and tear on the rolls, and lower operating costs. good 4
Since it is constructed using a high-pressure rolling mill, there is no need to worry about sheet meandering.

[Brief explanation of the drawings] Figure 1 is a diagram showing the relationship between lateral stiffness and plate width, and the bending effect coefficient and plate width; Figure 2 a, b, c
3 is a diagram showing the effect of lateral stiffness, FIG. 3 is a diagram showing the ratio between lateral stiffness and bending effect coefficient, and FIG. 4 is a block diagram showing a lateral stiffness variable control device according to the first embodiment of the present invention. , FIG. 5 is a block diagram showing a lateral stiffness variable control device according to a second embodiment of the present invention, FIG. 6 is a diagram showing changes in lateral stiffness according to the second embodiment of the present invention, and FIG. FIG. 7 is a diagram showing the influence coefficient on the plate crown according to the second embodiment of the present invention, FIG. 8 is a block diagram showing the lateral stiffness variable control device according to the third embodiment of the present invention, and FIG. 9 is a diagram showing the influence coefficient on the plate crown according to the second embodiment of the present invention. FIG. 7 is a block diagram showing a lateral stiffness variable control device according to a fourth embodiment of the invention. 1, 2... Work roll, 3, 3a, 4, 4a... Back roll, 5... Board, 6... Increase bender, 7
... Decrease bender, 11 ... Servo amplifier, 1
3, 28...Servo valve, 14...Load cell, 15,
15a, 15b... Lateral stiffness coefficient setter, 16, 16
a, 16b...Function unit, 17, 29...Summing amplifier,
18...Plate width setting device, 22...Hydraulic chamber, 24...Storage device, 25...Arithmetic unit, 33...Saturation value detector, 34...
Switch, 35... Converter, Q... Lateral rigidity, K _B ... Bending effect coefficient, C... Lateral rigidity coefficient, P _B ... Roll bending force.

[Claims]

1 On the roller conveyor 12 provided on the cooling bed 10 at intervals in the longitudinal direction of the cooling bed 10,
The wire rod 11 immediately after being hot-rolled is made into a planar spiral ring shape by shifting the pitch along the conveyor conveyance direction C, and the ring-shaped wire rod 11 is formed into a wire-dense part A in which the wires overlap closely on both sides and in the center. The wire rod 11 is placed and conveyed as a rough wire portion B with a rough portion.
A nozzle 14 is provided on the cooling bed 10 to be located below the conveying surface and between the roller conveyors 12.
In a device that performs controlled cooling using cooling fluid ejected through the conveyor, the upward angle θ of the nozzle 14 is set to 40° to 140° with respect to the horizontal plane of the cooling bed 10 in a vertical section along the conveyor conveyance direction C. In addition, the nozzle surface 14A of the nozzle 14 is a horizontal surface, and the cooling area corresponding to the coarse line part B with respect to the opening area of the nozzle 14 on both sides in the width direction of the cooling bed 10 corresponding to the dense line part A is The ratio of the opening area of the nozzle 14 at the center of the width direction of the floor 10 is 0.8 to
A cooling device for hot rolled wire rod, characterized in that the temperature is set to 1.2.

Claims (1)

A lateral stiffness variable control device, characterized in that the lateral stiffness variable control device is configured to calculate a roll bending force by multiplying the lateral stiffness coefficient by the function. 4 A valve device that controls the bender working fluid, a servo amplifier that receives a roll bending force setting signal and sends a control signal to the valve device based on the signal, and a servo amplifier that detects the working fluid pressure in the bender and controls the servo amplifier. 4. The variable lateral stiffness control device according to claim 3, wherein the bender control device is constituted by a feedback circuit for returning to the lateral stiffness. 5. The variable lateral stiffness control device according to claim 3 or 4, wherein a hydraulic chamber is provided inside the holding roll, and the surface profile can be changed by controlling the hydraulic pressure in the hydraulic chamber. 6. A rolling force detector, a device that locks on and stores the rolling force signal, and compares and calculates the rolling force signal stored by the device with the rolling force signal detected by the rolling force detector, and calculates the difference signal as the rolling force. The lateral stiffness variable control device according to claim 3, wherein a rolling force detection device is constituted by a computing unit that outputs as a signal. 7. A variable lateral stiffness control device for a plate rolling mill, which is equipped with a control device that controls the internal pressure of a hold-down roll that can change the surface profile by controlling the hydraulic pressure in an internal hydraulic chamber, and a A bender, a bender control device that receives a roll bending force setting signal and controls both bender based on the signal, and a device that sets the roll bending force and the internal pressure of the back roll, and the roll bending force The device for setting the inner pressure of the backing roll includes a rolling force detection device, first and second lateral stiffness coefficient setters for setting the lateral stiffness coefficient of the rolling mill, and a first lateral stiffness coefficient setting device having a function determined by the sheet width.
a second function unit, and a plate width setting device that sends a signal of a plate width value to the first and second function units, and the rolling force detected by the rolling force detection device and the first lateral stiffness The roll bending force is calculated by the lateral stiffness coefficient in the coefficient setter and the function in the first function unit, and the rolling force detected by the rolling force detector and the function in the second lateral stiffness coefficient setter are calculated. A set value for the internal pressure of the backing roll is calculated using the lateral stiffness coefficient and the function in the second function unit, and the internal pressure of the backing roll is input, and at the same time, a setting signal for the roll bending force is input to the bender control device. A lateral stiffness variable control device characterized in that the lateral stiffness variable control device is configured to be able to 8. A variable lateral stiffness control device for a plate rolling mill, which is equipped with a control device that controls the internal pressure of a backing roll that can change the surface profile by controlling the hydraulic pressure in an internal hydraulic chamber, and has a A bender, a bender control device that receives a roll bending force setting signal and controls both bender based on the signal, and a device that sets the roll bending force and the internal pressure of the back roll, and the roll bending force The device for setting the inner pressure of the backing roll includes a rolling force detection device, first and second lateral stiffness coefficient setters for setting the lateral stiffness coefficient of the rolling mill, and a first lateral stiffness coefficient setting device having a function determined by the sheet width.
a second function device, a sheet width setting device that sends a signal of a sheet width value to the first and second function devices, and a saturation value detector that detects a backing roll internal pressure saturation value; A roll bending force is calculated from the rolling force detected by the device, the lateral stiffness coefficient in the first lateral stiffness coefficient setting device, and the function in the first function device, and the roll bending force is detected by the rolling force detector. Calculate the set value of the backing roll internal pressure using the rolling force, the lateral stiffness coefficient in the second lateral stiffness coefficient setting device, and the function in the second function device, and when the backing roll internal pressure reaches the saturation value. A lateral stiffness variable control device, characterized in that it is configured such that a roll bending force setting signal can be input to a bender control device. 9. A rolling force detector, a device that locks on and stores a rolling force signal when the internal pressure of the backing roll reaches a saturation value, and a rolling force signal stored by the device and a rolling force detected by the rolling force detector. 9. The variable lateral stiffness control device according to claim 8, wherein the rolling force detection device includes a computing unit that compares and computes the signals and outputs the difference signal as a rolling force signal.