JPS59169614A - Forward slip controlling device - Google Patents

Abstract

PURPOSE:To keep rolling state stable and to improve rolling efficiency by detecting the delivery speed of a rolling material and the peripheral speed of a work roll to operate a forward slip basing on both speeds and controlling the peripheral speed of the work roll so that the operated value attains a prescribed value. CONSTITUTION:The delivery speed V2 of a rolling material 3 is detected by a speed detector 11 connected to a deflector roll 10 on the downstream of a rolling mill 9, and is inputted to a forward slip operator 12. Further, the peripheral speed VRH of a lower work roll 2 is detected by a speed detector 15 connected to a motor 7 of the roll 2, and is inputted to a forward slip operator 12. A forward slip fH is successively operated in the operator 12 basing on the speeds V2 and VRH by using an equation I , and is inputted to a forward slip controller 16. At that time, a set value fHO of forward slip and a set value VRL of the peripheral speed of roll 1 are previously inputted to the controller 16, and a peripheral speed correcting signal DELTAVRL of the roll 1 is operated. Then the operated value DELTAVRL is inputted to a main controller 13 to correct the peripheral speed of roll 1 so that the forward slip fH attains the fHO.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an advancement rate control device that controls the advancement rate of a rolled material during true speed rolling and performs stable and efficient rolling.

As the rolling speed increases, fluid lubrication between the work roll and the rolled material is promoted, and the neutral point gradually shifts to the exit side of the contact arc.
Eventually, the neutral point will move outside the contact arc, and the advance rate will become a negative value. In advanced heavy conditions where the neutral point is outside the arc, there is no point that determines the speed of the rolled material.
The speed of the rolled material becomes unstable. Such unstable rolling is
This is one of the causes of the vibration phenomenon called chatter marks. Even more! In A-speed rolling (rolling in which the circumferential speed of the lower work roll is changed), the rolling efficiency changes depending on the advance rate, as will be described later.

Therefore, controlling the advance rate to a required value is extremely important in maintaining stable rolling conditions and improving rolling efficiency.

The present invention was made in view of the above circumstances, and detects the outlet speed of the rolled material and the circumferential speed of the work roll, calculates the advance rate based on both speeds, and calculates the raw wave calculation result to a predetermined value. The present invention provides an advanced rate control device that controls the circumferential speed, that is, the rotational speed of a work roll so that the rotational speed of the work roll is adjusted to a certain value.

The present invention will be described in detail below with reference to the drawings.

First, let's talk about true speed rolling. As shown in Figure 1, [
The work roll on the second side (11 is set to the low speed side and its circumferential speed is
L % The lower work roll (2) is set to the high speed side, its circumferential speed is "R11" (of course, the lower side may be set to the low speed and the upper side is set to the high speed), and the speed of the input side of the rolled material (3) is set to the high speed side. Vo,
The speed on the exit side is v2, the rolled material (3) and the work roll tl)+
2) Let the frictional force between μP1 be α, the neutral point of the surface in contact with the rolling material t1 (3) and the upper work roll (11), and β be the neutral point of the surface in contact with the rolled material (3) and the lower work roll (2). For example, by detecting the difference in the circumferential speed "RL, VR" I of the upper and lower work rolls (Ll (2)), the neutral point α shifts to the input side, and the neutral point β shifts to the exit side, and the rolls and the rolled material There is a region where the direction of the frictional force μP between the upper and lower work rolls (1) f2+ is opposite, and as a result, the rolling load P decreases.

The high-speed side advancement rate fH in this true speed rolling is expressed as follows. If the relationship between this advancement rate fH, the true speed ratio VRH/VRI, and the rolling load P is shown in a diagram, it becomes as shown in FIG.

As is clear from Fig. 2, when the true speed ratio is increased, the advance rate fH decreases almost linearly, and the rolling force also decreases in the same way, but the rate of decrease becomes small when the advance rate fH approaches zero. .

When comparing this relationship with the advance rate, fH, and rolling force,
When the advance rate is decreased, the rolling force also decreases, and the decreasing tendency of the rolling force reaches a ceiling when the advance rate fII is near zero.

By controlling the advance rate to a constant value of zero or near zero, the rolling state can be stabilized and the rolling efficiency can be improved.

Next, the control device that controls the advance rate described above will be explained with reference to FIG. They are each pulled up by the backing roll (41 (5)) below -L, and are independently driven by the motor (6) (force) to be connected to the I/A.

Rolled material (3) rolled by upper and lower work rolls tl) (21)
is wound up by a tension reel (8) with a force applied to the required tension.

A deflector roll (10) is installed downstream of the rolling mill (9).
The rolled material speed detector (11) connected to the deflector roll (10) can detect the outlet speed v2 of the rolled material (3). Connect the rate calculator (12) so that the exit speed ν2 is input.

Motor (G) (7) has main controller <131 (+4
) is connected to the main controller (+31
5) Provide a motor (force speed lower than the working roll (2)
The circumferential velocity Va□ of is detected, and the detection result is further input to the advanced rate calculator (12). Further, the output signal JH from the advanced rate calculator 02 is input to the advanced rate controller t+e+, and the output signal ΔVRL from the advanced rate controller (16) is input to the master controller (131).

In the figure, VRTh is a circumferential speed setting signal of the upper work roll (1), fH is an advanced rate setting signal, and VR9<■RH.

Next, the operation will be explained.

The speed control of the motor (force) by the main controller (1a) is a constant speed control that keeps the circumferential speed VRI+ of the lower work roll (2) constant. It is determined by related equipment and serves as the standard for rolling.

The peripheral speed VR,I of the lower work roll (2) determined by the work roll speed detector (19) is determined by the advance rate calculation H (121
is input to the advanced rate calculator (in step 1, the above-mentioned (I) is combined with the input v2 from the rolling material speed detector (11)
The advanced rate fI (is calculated according to the formula.

A constant advanced rate setting value f8 of zero or close to zero is input in advance to the advanced rate control H (10, and the advanced rate controller 0
In step 6), the advance rates fg and fH are compared. Further, the peripheral speed setting signal vRI of the upper work roll (1) is inputted to the advance rate controller (16), and the peripheral speed correction signal ΔVRL of the upper work roll (1) is calculated based on these signals. The main controller (13) is inputted to the main controller (13).
31 is the circumferential speed of the upper work roll (1) when the advance rate fH is fg
Correct it so that it is equal to .

As a result, the advance rate is maintained close to or at zero, making it possible to stabilize the rolling state and improve rolling efficiency.

Note 1. (2) Although the first embodiment concerns the control of the advance rate in true speed rolling, it goes without saying that the advance rate can also be controlled in constant speed rolling using a similar method.

FIG. 4 is an explanatory diagram of an advanced rate control device in constant speed rolling, and the same parts as in FIG. 3 are given the same reference numerals.

In constant speed rolling, the upper and lower work rolls (1) (2+) are driven by the same motor (6), and the rolling rate is controlled to be constant by controlling the rotational speed of the motor (6). The rest is the same as shown in Figure 3.

As described above, in the present invention, since the advance rate can be controlled to a desired value, the rolling state can be kept constant and rolling can be performed with good rolling efficiency.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of true speed rolling, Fig. 2 is a diagram showing the relationship between true speed ratio, rolling force, and advance ratio in true speed rolling, Fig. 3 is a detailed explanatory diagram of the present invention, FIG. 4 is an explanatory diagram of another embodiment of the present invention. (3) is the rolled material, (6) (force is the motor, QD is the rolled material speed detector, (121 is the advanced rate calculator, (131 (14)
is the main controller, (1 is the work roll speed detector, (16 is
1 indicates an advanced rate controller. Patent applicant Ishikawajima Harima Heavy Industries Co., Ltd. Figure 1 Figure 2

Claims (1)

[Claims] I) A speed detector that detects the speed of the rolled material on the exit side of the rolling mill, a speed detector that detects the circumferential speed of the work roll, and an advanced rate calculator that calculates the advanced rate based on the signals from both detectors. and,
an advanced rate controller that outputs a work roll circumferential speed correction signal calculated based on the calculated advanced rate, the set input advanced rate, and the set input work roll circumferential speed; and the advanced rate controller output is inputted. An advanced rate control device comprising: a main controller that controls the circumferential speed of a work roll.