JPS5939410A - Rolling method - Google Patents

Abstract

PURPOSE:To control accurately the flatness after roughly controlling it by the controlled value of sheet crown, by installing a sheet crown detector between the stands of a front stage, and a flatness detector at the exit side of a final stand. CONSTITUTION:A detecting signal (Cr)a of a sheet crown detector 2 is transmitted to a sheet crown controlling device 3 to compare it with a set value (Cr)o, thereby a sheet crown correcting signal DELTACr is obtained to control the rolling reduction mechanism of a stand 4. Further a detecting signal (P)a of a flatness detector 6 is transmitted to a flatness controlling device 7 to compare it with a set value (P)o, thereby a flatness correcting signal DELTAP is obtained to control the rolling reduction mechanism of a final stand 5. Moreover, the signal DELTACr is transmitted to the device 7 to fetch it as the predictive controlled value of the flatness, thereby firstly the flatness of the stand 5 at the rear stage is roughly controlled and successively the flatness is accurately controlled by the signal DELTAP.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rolling method for controlling plate crown and flatness in a continuous rolling mill for copper strip.

Here, plate crown refers to the change in plate thickness in the width direction of the copper strip. Usually, the plate crown amount (Or) is given by the difference between the center thickness (hc) of the copper strip and the thickness (he) at a predetermined distance from the edge. That is, Or2hc-he
It is expressed as

Flatness refers to the wavy shape of the copper strip in the width direction or the same direction. Steepness (P%φ) is used as a measure to quantitatively express flatness. This steepness is expressed as a percentage of wave height (H) per unit wavelength (λ) for the wavy shape of the copper strip. That is, P -H/λ×100%.

Normally, steel plates are required to have a constant thickness in the width direction, but press-formed products, plated steel plates, etc. need to have different thicknesses in the width direction. Particularly in the case of plating materials, the plating layer tends to be thick at the edges, and an edge drop shape is required to make the edges of the material thinner. In this way, when various plate crown products are manufactured using the same rolling mill and the same rolling rolls, the reduction amount differs in the width direction of the plate, which inevitably tends to result in poor flatness. In particular, when a normal hot-rolled pickled steel strip is cold-rolled, it has a large tendency to elongate in the middle, making it extremely difficult to correct the flatness.

On the other hand, from the producer's perspective, theoretical minimum weight (TMW) products,
For items sold by calculated weight, such as cut plates, the smaller the plate crown, the less the yield loss. Threading workability of rolling mill,
When emphasis is placed on flatness, etc., rolling with a constant crown control number before and after rolling is preferred.

Conventionally, variable crown control has been used as a means of plate crown control.
Roll, intermediate roll shift type 6-heavy rolling mill, movement in sleeve type backup roll IJ-1 type work skew rolling mill, work roll different circumferential speed rolling mill,
There are flat rolls, rolls, crowns, chiseled rolling rolls, roll benders, roll coolants, etc.

Conventionally, there was no means for measuring the crown of a plate during rolling in a rolling mill, so the only way to respond to various steel plate product requirements was through predictive control, resulting in poor accuracy. Therefore, in order to improve accuracy, the plate crown was actually measured off-line, and the roll profile of the roll crown etc. was determined based on this actual measurement. On the other hand, regarding flatness control, flatness is detected on the exit side of the continuous rolling mill,
Feedback control controls the roll profile of the copper strip at the final stand 9. However, in none of these methods can a plate crown and flatness be obtained with sufficient accuracy.

An object of the present invention is to obtain a rolling method for producing an optimum copper strip by precisely controlling the plate crown and flatness of the copper strip.

The basic concept of the rolling method of the present invention is as follows. P1 of the plate crown] Since the reduction rate is large, do it on the stand in the previous stage; otherwise it will not be effective.

Therefore, at least one of the front stands is subjected to plate crown control. On the other hand, since the flatness control (I) may be a minute pressure F ratio, at least one of the stands in the latter stage is used for flatness control.

Yet another feature of the rolling method of the present invention is that the expected value of the flatness control amount is calculated in advance in accordance with the number of sheet crown controls, and this is sent to the corresponding stand in the subsequent stage to first coarsely control defects, and then flatten. The digit control is performed by feeding back the degree detection signal.

As a specific control method, when correcting the plate crown, if the central part of the copper strip has a high rolling reduction, it will tend to elongate in the middle, so the roll profile of the copper strip in the latter stand should be adjusted in advance so that the edge part has a high rolling reduction. After setting, fine adjustment is performed based on the amount of feedback from the flatness detector.

In the rolling method of the present invention, the plate crown measuring device is a plate thickness measuring device based on JP-A-56-128603;
In other words, using a steel plate edge horizontal digging type thickness gauge, and
As the flatness detector, a capacitance type, magnetostriction type, or tension distribution type detector is used.

Next, the rolling method of the present invention will be explained with reference to FIG. In the rolling method of the present invention, in a continuous rolling mill 1 for copper strip consisting of a plurality of stands, a plate crown detector 2 is provided between the front stands, and based on a plate crown detection signal from the detector 2, at least one of the front stands 9 is Perform plate crown control on the platform. That is, plate crown detector 2
The scrap detection signal (Or) a is sent to the plate crown control device B, where it is compared with the set value (Or) o to obtain the plate crown correction signal ΔGr = (Or) a - (Gr) o. Stand 4 to which the correction signal ΔCr applies
(in this embodiment, the first stand s), and the lowering mechanism of the stand 4 is controlled so that ΔGr becomes zero.

As a rolling mechanism, for example, a variable crown roll 11 (hereinafter referred to as c roll) as shown in FIG. 2(A) is used.
, a shift type intermediate roll 12 as shown in FIG. 2 (13)
(hereinafter referred to as HC roll), or a moving sleeve type roll 1 (hereinafter referred to as S roll) as shown in FIG. 2(G) can be used. Since these roles are well known, their explanation will be omitted.

Regarding the control of flatness, as well as the control of plate crown,
First, a flatness detector 6 is provided on the exit side of the final stand "'5, and plate crown control is performed for at least one of the subsequent stands based on a flatness detection signal from the detector 6.

, that is, the detection signal (P)a from the flatness detector 6
is sent to the flatness control device 7, where it is compared with the set value (p)0 and a flatness correction signal ΔP2(P)a − (P)o
force: determined, and this correction signal ΔP applies to the stand (
In this embodiment, the lowering mechanism of the final stand 4 is controlled so that ΔP becomes 0 when sent to the final stand 5).

As the rolling down mechanism, various rolls as described above can be used.

In the rolling method of the present invention, in addition to the flatness control described above, the following flatness control is also performed. The plate crown correction signal ΔCr mentioned above is sent to the flatness control device 7 and taken in as an expected control amount for flatness control, and the flatness of the corresponding stand 5 in the subsequent stage is first roughly controlled, and then the flatness correction signal ΔP is
The flatness is controlled by orders of magnitude.

Next, an example of the rolling method of the present invention will be described.

<Example 1> A pickled hot rolled steel plate with a thickness of 28 mm and a body of 1223 mm is cold rolled to a thickness of 0.8 Nn and a width of 1219+ffm. 6th
As shown in the figure, the first of the five-stand continuous cold rolling mill 1a
, S-roll 16 in the backup role of the second stand
Also, V in the backup role of the final stand.
C rolls 11 were placed respectively.

6Sδ (distance difference between steel plate edge and sleeve end) = -50
8, the plate crown (
The plate center plate thickness (hc - plate edge 10 point plate thickness he) was 60μ, but in this example it was 15μ, making it possible to draw 15μ thinner as a TMW product, and the yield loss of the TMW product was reduced by 9%.

The defective shape of the front stage stand was corrected to a good shape using the variable crown roll of the final stand. TMW product thinning control can determine the plate crown of a rolled steel strip from the difference between the plate center thickness gauge and plate edge thickness gauge, and optimally controls Sδ so that the difference with the target plate crown becomes zero. However, AG'C control may be performed based on the deviation between the plate edge thickness gauge and the target plate thickness.

<Example 2> Under the same conditions as in Example 1, if the filter is controlled to Sδ-+50, it becomes equivalent to quadruple rolling, and the overcoat phenomenon of the hot-dip Zn plated material can be countered with a plate crown similar to that of a conventional rolling mill. Ta.

<Example 6> Under the same conditions as in Example 1, when controlling 6Sδ=-258, the lateral rigidity became infinite and extremely good flatness was obtained.

<Example 4> In a continuous hot finishing mill, the base material thickness Qm+n is rolled to a finishing dimension of thickness 3.8 w x width 1235 runs.

As shown in Fig. 4, 6 stands continuous hot finishing rolling i
All stands of 1b are equipped with a mill equipped with shiftable intermediate rolls 12, and on the exit side of the final stand, there is a plate center thickness gauge 21 that can measure the plate crown in the rolled state, and can follow the edge of the steel plate against horizontal digging and meandering. An edge thickness gauge 22 was placed. Measure the plate crown using these thickness gauges 21 and 22, and adjust the HCδ of the front stand so that the value is small.
The intermediate roll was shifted to the ←) side, the shape deterioration there was corrected by HCδ control of the rear stage stand, and control was maintained when the front stage and rear stage controls were in balance.

As a result, a copper strip with a good shape and a small plate crown could be manufactured. In this example, the plate crown in the conventional rolling mill is reduced from 80μ to 50μ, and the TMW
Product yield loss decreased to 0.8%.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the rolling method of the present invention. FIG. 2 is a schematic explanatory diagram of various rolls used in the rolling method of the present invention. FIG. 6 and FIG. 4 are schematic configuration diagrams showing embodiments of the present invention. 1: Continuous rolling mill 2: Plate crown detector 6: Flatness detector 11: Variable crown roll 12: Shift type intermediate roll 13: Moving sleeve type roll Patent applicant Sumitomo Metal Industries, Ltd.

Claims (2)

[Claims] (1) In a continuous rolling mill for copper strips consisting of a plurality of stands, a plate crown detector is provided between the stands 8 at the front stage, and based on the plate crown detection signal from the detector, at least one of the stands 8 at the front stage is crowned. A rolling method comprising: providing a flatness detector on the exit side of the final stand; and controlling the plate shape of at least one of the subsequent stands based on a flatness detection signal from the detector. (2) In a continuous rolling mill for steel strips consisting of multiple strips, a plate crown detector is provided between the stands 8 in the front stage, and based on the plate crown detection signal from the detector, at least one of the stands 9 in the front stage is detected. A flatness detector is provided on the exit side of the final stand, and plate shape control is performed for at least one of the rear stands based on a flatness detection signal from the detector. A rolling method comprising first roughly controlling the flatness by taking in the crown control amount as a predicted control signal for flatness control, and then performing cloth control of the flatness based on the flatness detection signal.