SU435018A1 - METHOD OF REGULATING THE TRANSVERSE DIFFERENCE OF STRIPS PTB '' • -t ^ C: Y> & '^ ^ G8TYCH -' ^ '. U y: jaJ! ^ T I 00 - Google Patents

Description

I

There is a method of adjusting the transverse strip thickness variation by simultaneous anti-bending of the working and support rolls.

The disadvantage of this method is the use of maximum forces to bend both support and work rolls, as well as the use of a work roll deflection signal, which is not sufficiently accurate.

In order to increase efficiency and reduce control efforts, a method has been proposed in which simultaneous control is produced from a deflection signal by a rolling force, which is converted and divided into two in proportion to the bending force ratio, respectively, of the working and support rolls, equal to 0.3-0.4.

FIG. 1 shows schematically an embodiment of the proposed method; in fig. 2 illustrates the effectiveness of the method at different power ratios. A force Q is applied to the necks of the work rolls 1, and a force F is applied to the necks of the support rolls 2. On the side of the rolled strip 3, the rolling force P acts on the rolls. The total force RE on the working stand is perceived by the machine 4, measuring the force on the neck of the support roll. The total force signal is converted in device 5 and split in device 6. Thereafter, the signal

supplied simultaneously to the devices for adjusting the bending forces of the work rolls 7 and the support rolls 8.

The optimum ratio between the bending forces of the work rolls and the support rolls is determined from the following relationships.

Change in transverse thickness variation

b / g bands determined by roll deformations

from changing the rolling forces of 8Wp, the bending of eWq work rolls and the bending of the support rolls

8Wy rolls:

(one)

bh bWp-WQ -bWF

Roll deformations are proportional to load changes, then

SP8-2Qb-2P

(2)

Ih -

M%

M,

M,

Here, M, in are the coefficients of the stiffness of the rolls, respectively, from the rolling force P, the bending of the work rolls Q and the bending of the support rolls F, which are in general non-linear functions of the roll mill flattening and mill parameters. To achieve the zero thickness variation from (2) we have

M

M}

.. oQ оР

(3)

F 2bF M.

M

Thus, the proportionality coefficient K. between changes in the forces of bending of the working and support rolls depends on the change in the rolling force and the stiffness coefficients of the rolls. This shows that with the action of only one type of anti-bend, maximum adjustment forces are required. Under the action of simultaneous anti-bending of the support and work rolls, a change in the forces is required within narrow limits.

For example, for a typical sheet mill, the calculated efficiency of simultaneous bending of the working and support rolls at different force ratios is shown in FIG. 2. On the right are the curves of the ratio of the bending force of the support rolls F to the rolling force P depending on the ratio of the width of the strip B to the length of the barrel rolls L. On the left are the curves of the ratio of the bending effort of the working rolls Q to P depending on B / L. It is seen that when bending only the work rolls (), the maximum effort 2Q revenue t to 35% of the rolling force P.

With simultaneous bending of the support and work rolls in a ratio of 4 F, the force per work rolls is reduced more than twofold. When bending only support rolls

(Q 0) maximal effort 2F yields t to 70% of P, and with simultaneous bending, it is almost halved. The performed calculation using expression (3) for several typical mills showed that the greatest reduction in control is achieved at Q (0.3-0.4) f.

Subject invention

The method of adjusting the transverse difference; strip inaccuracies by simultaneously bending the work rolls and backing rolls, characterized in that, in order to increase efficiency and reduce adjustment efforts, adjustment is made from a rolling force deflection signal, which is converted and divided by two in proportion to the bending effort, respectively working and backup rolls, equal to 0.3-0.4, Q - 0.2f /, / 2 U.9 6 & 0.7 O.S 0.5 0 0.5 O.B. Fig 2 QD.2F dO.P QD.Bf 0.1 0.8 0.9