JPS5935820A - Control method of rolling mill - Google Patents

Abstract

PURPOSE:To eliminate the delay of feed back, and to improve productivity, by providing a device for detecting an unit weight (weight per unit length) of each product instead of providing a shape detector, and controlling the roll gap of a finish mill of a rod mill. CONSTITUTION:A rolling mill 1, a roll driving motor 4, a pulse generator 5, a pulse counter 7, detectors 2, 3 for detecting a base material to be rolled, an input device 8 for inputting the informations of the material, and an arithmetic control device 6 are provided respectively. Then, the total length (l) of the material and the unit weight WU of it are obtained, and a target unit weight WA to be controlled is obtained basing on the unit weight of JIS and the allowable minimum unit weight of JIS. Successively, a roll gap correcting quantity DELTAh= (WU-WA)/rho.B is calculated by the device 6 basing on the unit weight AA, the unit weight WU of the base material, the density rho of the material, and the width B of the cross section of the material. Thus the roll gap is controlled, and the productivity is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION fa) Description of the Technical Field The present invention mainly relates to a control device for controlling the roll gap (reduction amount) of a cut rolling mill for a steel bar mill or a steel shape mill.

(b) Description of the prior art In steel mills, shape steel mills, etc., the rolled product is more three-dimensional than in hot strip mills, cold strip mills, etc. Thickness control is difficult, and there is usually only preset control that sets the roll gap and speed before rolling.

Further, the preset value was also usually set so that the rolling dimension was around the median value of the JIS standard range. However, if this can be made close to the lower limit of the JIS standard range, production can be increased because the same material can be rolled longer. However, the current situation is that there are no dimension measuring instruments with high measurement accuracy that can be used for automatic control.

However, although there are many measuring machines that can measure the dimensions of stationary materials with high precision, the dimensions of materials that are moving at a constant speed (10-odd meters to several tens of meters) cannot be measured accurately, except for flat plates. There is nothing good. For this reason, the current method of rolling operation is to manually measure the dimensions of the product using calipers, etc., and then communicate this data to the rolling operator to correct the roll gap preset value. Feedback to the gap was slow, and the set value had to be set on the safe side (the median value of the standard allowable range).

(cl) Purpose of the present invention The present invention eliminates the delay in feedback to control as described above, automatically corrects the pressure preset value, and improves the long length of paper after rolling from the same material within the size specified by the standard. The purpose is to provide a highly productive rolling mill control method that can obtain products.

(di) Structure of the Invention The gist of the present invention is to provide a device for determining the unit weight of a product instead of a shape detector, and to combine this with a device that determines the unit weight of a product based on the dimensions specified in the JI8 standard (unit weight corresponding to JIS standard dimensions). JIS
One embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram for implementing the present invention.

1 is a finishing rolling mill, 2.3 is a rolled material detector installed on the downstream line from rolling mill 1, 4 is an electric motor for driving the rolls of rolling mill 10, 5 is a pulse generator attached to electric motor 4, and 6 is an arithmetic control unit. A device, 7 is a pulse counter provided inside the arithmetic and control device 6, 8 is an input device (setting board, information processing, computer, etc.) for inputting material information, product information, etc. from the outside, 1
0 is the pass line of the rolled material, 11 is the rolling mill 1 and the electric motor 4
12 is a connection shaft that mechanically connects the rolling mill 4 and pulse generator 5, 13 is a pulse number 18 generated from the pulse generator, and 14 is a material stuck in the rolling mill 111. 15 and 16 are material detection signals from the rolled material detectors 2 and 3, respectively, and ]7 is input information from the input device #8 to the arithmetic and control unit 6.

FIG. 2 is a diagram showing the shape of the hole in the pass line of the hole roll and the material. The figure (1) is an example of a steel bar, and the figure (2) is an example of a shaped steel.Here, B means the dimension corresponding to the width of the hole die.

Ie) Effect of the invention Two pulse counters A inside the arithmetic and control unit.

have B. A counter A counts pulse signals generated by the pulse generator 5 from when the material is bitten into the rolling mill 1 to when the material is removed from the bottom. The counter B counts the pulse signals generated by the pulse generator 5 from when the material passes through the first rolled material detector 2 until when the material passes through the second rolled material detector 3. Count value of counter B' (rno, distance between sensors 2 and 3) *12. Then,
If the amount of material movement after rolling per one pulse is 'tlp, it is obtained as follows: 1P-lt3/nB (1). Next, if the count value of counter A is nA and the total length of the material after rolling is l, then l ke A = apXnΔ
...It is obtained by (2). Next, from the material type F4 W of the rolled material information, the weight per unit length (referred to as unit weight) of the material after rolling is determined by WuFi = W/11 (31).

On the other hand, the cross-sectional shape size of the product information (in the case of a round bar, it is the product diameter, and in the case of an H-beam steel, the web height type, 7-lunge width, web thickness, and 7-lunge thickness are given) or the JIS standard number. , it is possible to calculate the unit weight according to the JIS standard. The unit weight of this JIS standard is WJ. Next, the unit weight kWX is calculated from the minimum cross-sectional size that passes the JIS standard based on the dimensional tolerance defined in the JIS standard.

The core of the present invention is to calculate the total actual unit weight from easily measurable length and weight in order to avoid the difficulty of directly defining the cross-sectional shape.
By comparing this with the target unit weight, which is the target product size converted to unit weight, the roll gap can be fully controlled. First, the control target unit weight WA is determined using the following formula.

WA-WJ'arrow k + W, Shigeru (1-k) ・;4
) Here, k is a coefficient that determines how close the target is to the JIS standard allowable minimum size, and is a value in the range of =o to 1.

When k-=1, the goal is to set the minimum size, and k
=O means that the size is set according to the JIS standard.

Next, find the roll gap correction amount Δh using the following formula.

Here, ρ: Specific gravity of the material B: Width of the roll hole shape shown in Fig. 2 (in the cross section of the material) By controlling the roll gap to be smaller by the roll gap Δh determined by equation (5), the unit weight of the material after rolling can be reduced. Wυ
It is controlled more by WA.

Since the roll gap setting control is a known technology,
Explanation will be omitted.

In addition, when the next material is rolled with the roll gap obtained by fully correcting the roll gap by △h determined by equation (5), and the unit weight does not become the control target unit weight WA but becomes wu', the amount of roll gear correction is Δh' is determined by the following formula.

This formula assumes that the B value in formula (5) is different from the actual rolling, and uses the actual rolling results (where the gap is changed by △h, W,
Using equation (5), calculate B inversely (B = = v! - convex) from (Wu' became Wu'), and use equation (5) ρ, Δb to bring Wu' to WA. ' is calculated. In this case, when the control target cannot be achieved by one roll gap correction, it can be brought within the allowable value by repeating the above action several times.

+fl Other Embodiments In a configuration example for implementing the present invention, counter A,
, B is an internal counter of the arithmetic and control device, but it is also possible to use an external counter and read the counter value into the arithmetic and control device when the material runs out.

fg) Effects of the Invention As described above, according to the present invention, the roll gap can be controlled without adding any new devices, detectors, etc. to the conventional control device, and higher productivity can be achieved. become.

[Brief explanation of the drawing]

FIG. 1 is a block diagram for carrying out the present invention, and FIG. 2 is a diagram showing the hole shape in the pass line of the hole roll and the material. 1. Rolling mill 2.3. Rolled material detector 4
Roll drive electric motor 5 Pulse generator 6-arithmetic control device 7 Pulse counter 8 Human power device Fig. 1 Fig. 2 (1) (2)

Claims (1)

[Claims]! A rolling mill that rolls rolled materials such as lj m steel or type steel, a core motor that drives the rolling rolls of this rolling mill, a pulse generator installed in this electric motor that measures the motor rotation speed, and There is a distance of 4 seconds between a pulse counter that counts pulses from the pulse generator and a pulse counter that is installed downstream of the rolling mill and that detects the passage of the rolled material.
Just the name set apart. 1st. a second rolled material detector; an input device for inputting information regarding the rolled material; and the first. The apparatus includes an arithmetic control device that performs predetermined calculations based on the output of the second rolled material detector, the counted value of the pulse counter, and information from the input station, when the rolled material is detected by the first.
The pulse nB of the pulse generator generated while passing through the second rolled material detector and the first . The movement drlp of the rolled material per pulse is calculated from the distance between the second rolled material detectors ^30), and the total length of the rolled material after rolling 1 is determined from this movement tlP and the number of pulses n4 from the start of rolling to the end of rolling of the rolled material. 'x is calculated, and from the obtained total length l of the rolled material and the weight W of the rolled material inputted from the input device, the unit weight Wuk, which is the unit length weight of the rolled material after rolling, is calculated, and the JIS standard unit weight WJ and JIS standard allowable minimum unit weight WJ'
The control target unit weight WA f is determined from this unit weight W, the unit weight WU of the rolled material after rolling, the rolled material density ρ, and the rolled material cross-sectional width B, and the roll gap correction amount Δh is sent to the arithmetic and control device. A rolling mill control method characterized by performing calculations based on the following. +2i Rolling rolling materials such as FM steel or type steel:
E rolling mill, an electric motor that drives the rolling rolls of this rolling mill, a pulse generator provided in this electric motor for measuring the rotation speed of the electric motor, a pulse counter that counts pulses from this pulse generator, and the rolling machine. A distance l is provided between the two to detect the entire passage of the rolled material.
. The first one, which is installed at a distance of a second rolled material detector; an input device for inputting information regarding the rolled material; and the first. The apparatus further includes an arithmetic control device that performs predetermined calculations based on the output of the second rolled material detector, the count value of the pulse counter, and information from the input device, wherein the rolled material is detected by the first rolled material. The pulse nB of the pulse generator generated during passing through the second rolled material detector and the first . The amount of movement IP of the rolled material per pulse is calculated from the second rolled material detector distance To3, and this amount of movement IJp
and the number of pulses n from the start of rolling to the end of rolling of the rolled material
The total length l of the rolled material after rolling is determined from A, and the unit weight WU, which is the unit length weight of the rolled material after rolling, is determined from the determined total length l of the rolled material and the weight W of the rolled material input from the input device.
In addition, the control target unit weight WA k is determined from the JIS standard unit weight W□ and the JIS standard allowable minimum unit weight WJ', and this unit weight W^, the unit weight Wσ of the rolled material after rolling, the rolled material density ρ, and the rolled material Calculate the correct amount △hl from the cross-sectional width B of the roll gap with corrected flexibility, and when the roll gap is actually changed by the calculated roll gap correction amount △h, the control target unit weight of the rolled material after rolling will not be WA. When WO2 is reached, this control target unit weight WU', the control target unit weight WA and unit weight W[1 during the previous rolling and the previous roll gap correction amount Δh
A rolling mill control method characterized in that the further roll gap correction amount Δh' is calculated by the arithmetic and control device.