JPH09155423A - Hot lubrication rolling method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid the slip between a rolled stock and a roll by constantly measuring the stand outlet side plate speed and the roll speed for each stand to estimate the advance ratio of the stand in a hot rolling, and adjusting the quantity of application of the lubricating fluid according to the value. SOLUTION: In a hot lubricating rolling, an advancement ratio estimation arithmetic unit 200 constantly measures the plate speed and the roll speed during the rolling using a plate speed meter 105 and a roll speed control system 104, and constantly estimates the advance ratio of each stand from the measured value. The estimated value of the advancement ratio is given to a lubricating fluid application quantity control device 300. The appropriate value 301 of the advancement ratio and the reference value 302 of the lubricating fluid application quantity are set in the lubricating fluid application quantity control device 300, and the correction of the application quantity of the lubricating fluid is determined to appropriately keep the estimated value of the advancement ratio estimated by the advancement ratio estimation arithmetic unit 200. The corrected lubricating fluid application quantity is determined by opening/closing a lubricating fluid application opening/closing valve 404, and given to a flow rate control device 405 of the lubricating fluid as the target flow rate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot lubrication rolling method which enables stable lubrication rolling by avoiding slip between a rolling material and a roll during rolling in hot lubrication rolling using a tandem rolling mill. It is about.

[0002]

2. Description of the Related Art In recent years, in hot rolling using a tandem rolling mill, hot lubrication rolling has been carried out for the purpose of reducing rolling power, reducing work roll wear and improving strip profile.

As shown schematically in FIG. 2 in which the lubricating fluid is supplied, the method is constant after a load cell detects a rolling load in each rolling mill (hereinafter called a stand) of a tandem rolling mill. After time T1 or when the delivery side plate length reaches a certain length L1, a lubricating fluid in which a lubricant is mixed in water at an appropriate concentration is sprayed directly onto the surface of a work roll (hereinafter referred to as a roll) to be applied. Or, spray the spray on the surface of the backup roll to transfer the lubricating fluid to the roll and roll it, and predict the time when the rolled material will pass through each stand. The spraying of the lubricating fluid is stopped when the length reaches a certain length L2, and the lubricating fluid remaining on the roll surface after passing the rolled material is limited, so that the rolling material and the roll during the stand biting of the succeeding rolled material It is common to avoid the lip.

As a hot lubrication rolling method for obtaining the above-mentioned lubrication rolling effect, in JP-A-57-199501, the friction coefficient of a roll is measured, and the measured value is determined by the material of the rolled material and the rolling conditions. A hot lubrication rolling method is disclosed in which the amount of the lubricating fluid applied is adjusted so as to maintain an appropriate range. Further, JP-A-58-167018 discloses a hot lubrication rolling method in which a wear profile of a roll is measured, and an injection amount of a lubricating fluid is adjusted based on the measured value so that the roll is uniformly worn in the axial direction. Has been done.

[0005]

In order to prevent the slip between the rolled material and the roll from occurring during rolling and to maximize the above-mentioned lubricative rolling effect, the optimum amount depending on the material of the rolled material and the rolling conditions is used. However, it is difficult to find the optimum value because the determinants of this optimum value are various, such as rolling torque, roll speed, rolling reduction, temperature of rolled material and steel type.

The above-mentioned JP-A-57-199501 and JP-A-58-167018 were devised as a method for efficiently feeding the lubricating fluid into the roll bite. However, in order to measure the friction coefficient of the rolls and the wear profile of the rolls described in these publications, it is necessary to install a friction coefficient measuring device or a wear profile measuring device in the very vicinity of the roll in a very bad measuring environment, and to stabilize the stability. It was very difficult to measure them, and the reliability of measured values was low. For this reason, a low amount of the lubricating fluid is applied so that slipping does not occur during rolling, and the effect of lubrication rolling is not sufficiently obtained under the present circumstances.

Therefore, according to the present invention, the plate speed and the roll speed meter provided for each stand are used to constantly measure the plate speed and the roll speed during rolling to estimate the advanced rate. By adjusting the lubrication fluid application amount so as to maintain an appropriate value determined by the material of the rolled material and rolling conditions, it is necessary to avoid slip between the rolled material and the roll and to achieve stable lubrication rolling. To do.

[0008]

In order to solve the above problems, the present invention provides a hot lubrication rolling method using a tandem type rolling mill equipped with a lubricating fluid supply device for applying a lubricating fluid to a rolling roll. , The stand exit side plate speed meter and roll speed meter provided in advance for each stand constantly measure the stand exit side plate speed and roll speed, and estimate the advanced rate of the stand from the obtained measurement value, and estimate the advanced rate The amount of the lubricating fluid applied to the roll surface is adjusted according to the value, and the estimated value of the advanced ratio is set to an appropriate value determined in advance depending on the material of the rolled material and the rolling conditions from the start of the lubrication rolling to the end of the lubrication rolling. Hold in value.

In the present invention, the appropriate value of the advance rate of each stand is a value that does not cause the slip of the rolled material and the roll during rolling and can sufficiently exert the effect of the above-mentioned lubrication rolling.
It is determined empirically based on past rolling data or analytically based on a mathematical model of rolling characteristics.

As a result of various hot lubrication rolling tests using a small rolling mill under the same lubricating conditions such as lubricant and lubricant concentration, as shown in FIG. Are in inverse proportion to each other, and when the lubricating conditions such as lubricant and lubricant concentration are the same, the advanced rate decreases as the amount of lubricating fluid applied increases, and conversely the more advanced the amount of lubricating fluid applied decreases. It was confirmed that the rate will improve. That is, it was confirmed that the advanced rate can be controlled by manipulating the coating amount of the lubricating fluid when the lubricating conditions such as the lubricant and the lubricant concentration are the same.

Therefore, the strip speed and the roll speed at each time point (k) during rolling are measured, and the advanced rate is estimated as f (k) = Vo (k) / Vr (k) -1 (1), PI (proportional integral) control law DQ (k) = Kp {f (k-1) -f (k)} + Ki {F-f (which uses an appropriate value of the advanced rate determined by the material of the rolled material and rolling conditions k)} + DQ (k-1) (2) The correction amount of the lubrication fluid application amount is determined, and the optimum lubrication fluid application amount is determined according to the material of the rolled material and the rolling conditions. Can be held at an appropriate value,
Slip between the rolled material and the roll can be avoided, and stable lubrication rolling can be performed.

Here, Vo (k) is the stand exit side plate speed [m / sec] measured by a plate speed meter, Vr (k) is roll speed [m / sec] measured by a roll speed meter, and F is a rolled material. Appropriate value of the advanced rate [-], f determined by the material and rolling conditions of
(K) is an estimated value of the advanced rate [-], Kp is a proportional control gain [m ³ / Hr], Ki is an integral control gain [m ³ / Hr], D
Q (k) is a correction amount [m ³ / Hr] of the lubricating fluid application amount.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a configuration of the present invention. 100 is a rolling line including a tandem type rolling mill, 200 is an advanced ratio estimation arithmetic device according to the present invention, and 300 is a lubricating fluid application amount according to the present invention. A control device 400 is a lubricating fluid supply device.

In the rolling line 100, 101 is a rolled material, 102 is a work roll, 103 is a backup roll, 104 is a roll speed control system using a DC motor for driving the work roll 102 or an AC motor having a faster response, 105 Reference numeral 106 is a plate speed meter to which a laser Doppler is applied to measure the plate speed on the stand exit side. Reference numeral 106 is a lubricating fluid for spraying a lubricating fluid onto the surface of the backup roll 103 and transferring the lubricating fluid to the work roll 102. It is a coating nozzle.

The lubrication fluid is supplied from the lubrication fluid tank 401 in which the concentration of the lubricant or the lubricant is adjusted to a constant value to the flow control valve 4
02, the oval flow meter 403, and the lubrication fluid application on-off valve 404, and is jetted from the lubrication fluid application nozzle 106 to the backup roll 103. Reference numeral 405 denotes a lubrication fluid flow rate control device, which is a lubrication fluid application amount control device 3
The target flow rate of the lubricating fluid is realized by operating the flow rate control valve 402 based on the deviation between the target flow rate determined by 00 and the actual flow rate measured by the oval flow meter 403. Reference numeral 406 denotes a control device for the lubricating fluid application on-off valve 404. As shown schematically in FIG. 2, the lubricating fluid application on-off valve 404 is opened after a certain period of time after the rolled material 101 has been bitten into each stand. The application of the lubricating fluid is started, the time at which the tail end of the rolled material 101 leaves the stand is predicted, and the application opening / closing valve 404 is closed to stop the application of the lubricating fluid at a certain time before the application, and the application is opened / closed. An opening / closing signal of the valve 404 is given to the lubricating fluid application amount control device 300.

The advanced rate estimation arithmetic unit 200 constantly estimates the advanced rate by the above formula (1) from the strip speed and the roll speed constantly measured during rolling using the strip speed meter 105 and the roll speed control system 104, The estimated value of the advanced rate is given to the lubricating fluid application amount control device 300. Lubrication fluid application amount control device 3
In 00, 301 and 302 are empirically determined based on past rolling data or analytically determined based on a mathematical model of rolling characteristics and an appropriate value of the advanced rate and a reference value of the lubricating fluid application amount, and 303 is An arithmetic unit for calculating the correction amount of the lubricating fluid application amount shown in the equation (2) for holding the estimated value of the advanced rate at an appropriate value, 304 is the lubricating fluid application amount by the opening / closing operation of the lubricating fluid application on-off valve 404. It is a corrector for the amount of lubricating fluid applied, which corrects the reference value of.

The procedure for setting the lubricating fluid application amount (target flow rate of the lubricating fluid) in the lubricating fluid application amount control device 300 will be described below. Here, in the present apparatus, the appropriate value of the advanced rate and the reference value of the lubricating fluid application amount, which are experimentally determined based on past rolling data or analytically determined based on the mathematical model of the rolling characteristics, are set in advance. deep.

[Procedure 1] Advanced rate estimation arithmetic unit 200
The correction amount of the lubricating fluid application amount for keeping the estimated value of the advanced rate estimated by the above to be an appropriate value is determined by the above equation (2).

[Procedure 2] Lubrication fluid application on-off valve 404
The reference value of the lubricating fluid application amount is corrected by the opening / closing operation of the above to determine the lubricating fluid application amount, and the determined value is given to the lubricating fluid flow rate control device 405 as a target flow rate. When the lubricating fluid application opening / closing valve 404 is ON, that is, during the application of the lubricating fluid Q (k) = DQ (k) + Qb (3) When the lubricating fluid application opening / closing valve 404 is OFF, that is, the application of the lubricating fluid During stop Q (k) = Qb (4) where Qb is the reference value of the amount of lubricating fluid applied [m ³ / H
r] and Q (k) are target flow rates [m ³ / Hr] of the lubricating fluid.

[0020]

As described above, according to the method of the present invention, since the advanced ratio is maintained at an appropriate value determined by the material of the rolled material and the rolling conditions, slip between the rolled material and the roll during rolling can be avoided. As a result, stable hot lubrication rolling becomes possible.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of the present invention.

FIG. 2 is a schematic diagram of a procedure for supplying a lubricating fluid.

FIG. 3 is a characteristic diagram of an advanced rate with respect to a lubricating fluid application amount.

[Explanation of symbols]

100: Rolling line composed of tandem rolling mill 101: Rolled material 102: Work roll 103: Backup roll 104: Roll speed control system 105: Plate speed meter 106: Lubricating fluid application nozzle 200: Estimating arithmetic unit for advanced rate 300: Lubrication fluid application amount control device 301: Proper value of advanced rate 302: Lubrication fluid application amount reference value 303: Lubrication fluid application amount correction amount computing device 304: Lubrication fluid application amount corrector 400: Lubrication Fluid supply device 401: Lubrication fluid tank 402: Flow rate control valve 403: Oval flow meter 404: Lubrication fluid application on-off valve 405: Lubrication fluid flow rate control device 406: Lubrication fluid application on-off valve control device

Claims (1)

[Claims] 1. In a hot lubrication rolling method using a tandem rolling mill equipped with a lubricating fluid supply device for applying a lubricating fluid to a rolling roll, a stand exit side plate speed meter and roll provided in advance for each stand The stand outlet plate speed and roll speed are constantly measured by a speedometer, the advanced rate of the stand is estimated from the obtained measurement values, and the amount of lubricating fluid applied to the roll surface is adjusted according to the estimated advanced rate. Then, the estimated value of the advanced rate is maintained at an appropriate value that is predetermined according to the material of the rolled material and the rolling conditions from the start of the lubrication rolling to the end of the lubrication rolling.