JPH07284819A - Rolling control method - Google Patents

Abstract

PURPOSE:To control the coefficient of friction so as to become the target value by keeping lubricity at the time of rolling in the proper state based on actual rolling data. CONSTITUTION:The actual rolling data are inputted, an actual coefficient of friction for each stand is calculated 112 based on the data, the deviation between the actual coefficient of friction and preset optimum target coefficient of friction is calculated 114 and the optimum supply of rolling oil for each stand is calculated 116 based on this deviation to control a device 120 for changing the feed rate of rolling oil for each stand so as to be the optimum supply of rolling oil for each stand.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rolling control method, and in particular, it controls the supply amount of rolling oil based on actual rolling data,
The present invention relates to a rolling control method capable of performing rolling control so as to achieve a target friction coefficient.

[0002]

2. Description of the Related Art In the case of rolling a material to be rolled such as a steel plate, generally, by reducing the coefficient of friction between a rolling roll constituting a rolling mill and the material to be rolled, the working is facilitated and the material to be rolled is rolled. Rolling oil is used to finish the surface of the material beautifully.

However, when the rolling oil is used for rolling in this way, if the rolling oil is not properly supplied, insufficient lubrication occurs between the material to be rolled and the rolling rolls, and a seizure phenomenon called heat streak occurs. May occur, or conversely, over-lubrication may occur and a slip phenomenon called chattering may occur.

Therefore, in a normal rolling operation, the amount of rolling oil supplied is adjusted so that the lubricity between the rolling roll and the material to be rolled is maintained between the heat streak occurrence limit and the chattering occurrence limit. Is being done.

If the amount of the rolling oil supplied is not properly adjusted in this way, the quality of the rolled material deteriorates,
As a result, productivity is significantly impaired.

[0006] Conventionally, as a method for adjusting the amount of rolling oil supply applied to the rolling operation, for example, Japanese Patent Publication No. 63-124, according to conditions such as roll roughness change that can be predicted before rolling and the material of the rolled material, etc. A method of adjusting the supply amount of rolling oil by presetting is disclosed.

[0007]

[Problems to be Solved by the Invention] However, originally,
The friction coefficient that determines the state of lubricity during rolling changes depending on many factors such as the amount and viscosity of rolling oil supplied, the rolling speed, the rolling reduction, the biting angle, the deformation resistance of the material to be rolled, and the roll roughness. Therefore, the method of adjusting the rolling oil supply amount by indirectly predicting the state of lubricity during rolling from the roll roughness and the material of the material to be rolled disclosed in the above publication is inferior in prediction accuracy. In addition, there is a problem that it is not possible to cope with rolling conditions that change from moment to moment.

The present invention has been made to solve the above-mentioned conventional problems. Based on the actual rolling data, the lubricity during rolling is maintained in an appropriate state, and the friction coefficient is controlled to a target value. By doing so, it is an object to provide a rolling control method capable of rolling with high accuracy.

[0009]

According to the present invention, in a rolling control method for rolling a material to be rolled while supplying rolling oil, the actual friction coefficient is calculated using the actual rolling data, and the calculated actual friction is calculated. The above problem is solved by controlling the supply amount of rolling oil so that the coefficient becomes the target friction coefficient.

In the rolling control method according to the present invention, the rolling oil is supplied by using a highly responsive spray header capable of internally mixing the rolling oil and water to form an emulsion. It is a thing.

According to the present invention, in the above rolling control method, an oil supplied to a central portion as a spray header,
An inner pipe having a mixing portion that mixes water supplied from both end portions through the ejector portion to form an emulsion at the downstream side of the central portion, and the inner pipe is accommodated inside and is sent out from the mixing portion. An outer tube having a nozzle for injecting an emulsion is provided, and a part of the emulsion delivered to the outer tube flows into the inner tube through a through hole formed in the ejector portion so as to circulate. It uses a self-circulating spray header.

[0012]

In the present invention, the actual friction coefficient is calculated from the actual rolling data, and the supply amount of the rolling oil is controlled so as to obtain the optimum friction coefficient targeted for the actual friction coefficient. It becomes possible to maintain a lubricated state, and it is possible to improve productivity and quality without generating heat streaks or chattering.

Further, in the present invention, for example, when a self-circulating spray header as shown in FIG. 3 described later is installed between stands and a rolling oil supply system including this spray header as shown in FIG. 4 is used. For each stand, mix rolling oil and water (warm water) in the spray header,
Since it is possible to supply the rolling oil as an emulsion to the material to be rolled such as strip in an extremely short time, the responsiveness of changing the amount of the rolling oil supplied can be significantly improved, and the change can be made within 0.5 seconds, for example. Can be achieved. Therefore, when the system including the spray header shown in FIG. 3 is used, rolling control with extremely high precision can be performed.

[0014]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is a flow chart showing a processing procedure of a rolling control method according to an embodiment of the present invention.

This embodiment is, as shown in FIG. 2, a cold tandem rolling mill including a plurality of rolling stands connected in series for continuously rolling the strip 1 supplied from the pay-out reel through the looper. , Control for calculating the friction coefficient from the actual rolling data for each stand and adjusting the supply amount of rolling oil according to the method detailed later based on the deviation between the actual friction coefficient and the optimum (target) friction coefficient Here is an example.

In the tandem rolling mill described above, a self-circulating spray header as shown in a sectional view in FIG. 3 is provided in front of the No. 1 stand and between the stands, close to both front and back surfaces of the passing strip 1. The rolling oil is supplied as an emulsion from the rolling oil supply system shown in FIG. 4 to the spray header independently for each stand.

First, a spray header applied to this embodiment and a system for supplying rolling oil to the spray header will be described. This spray header and system are disclosed in Japanese Patent Application Laid-Open No. 3-27316 by the present applicant.
3 are proposed.

In the rolling oil supply system, as shown in FIG. 4, a pair of spray headers 2 and 2'are arranged close to the upper and lower sides of the strip 1, respectively. The rolling oil is supplied from the oil supply pipe 5 by the oil supply control pumps 7 and 7 ′, and the water is supplied from the water supply pipe 6 by the water supply control pump 12. Further, the oil supply control pumps 7 and 7'are flow controlled by oil supply control motors 8 and 8 ', respectively, and the water absorption control pump 12 is similarly flow controlled by the water supply control motor 13.

The spray headers 2 and 2'are shown in FIG.
As shown in FIG. 2, each has a double structure consisting of an outer pipe 9 and an inner pipe 10 housed inside thereof, and the rolling oil is directly supplied from the oil supply pipe 5 to the central portion of the inner pipe 10, Is directly supplied from the water supply pipe 6 to both ends 14, 14 'of the inner pipe.

The water supplied to the spray headers 2 and 2'is the end portions 14 and 14 'of the inner pipe 10 and the ejector portion 1
5, 15 ′ → trunk portion 19, 19 ′ → throttle portion 17, 17 ′ to reach the central enlarged portion (mixing portion) 18. Also, the inner pipe 10
The rolling oil supplied to the central portion of the oil reaches the central enlarged portion 18 via the squeezing portions 17 and 17 ', where it is mixed with water to form an emulsion.

The emulsion is delivered to the outer tube 9 through the communication hole 11 formed in the central enlarged portion 18, and the front surface and the back surface of the strip 1 are discharged from the nozzle 3 arranged outside the outer tube 9. Is ejected into the holes 16, 1 due to the ejector function of the ejector portions 15, 15 '.
It is guided to the barrel portions 19 and 19 'of the inner pipe 10 through 6'.
The emulsion introduced into the body portions 19 and 19 'is mixed with water (diluting water), and again introduced into the central expansion portion 18 via the squeezing portions 17 and 17', where it is mixed with rolling oil and newly added. Similarly, the emulsion is sprayed from the nozzle 3 and the rolling oil in the emulsion is applied to both front and back surfaces of the strip 1.

As described above, the spray headers 2, 2 '
Then, the oil supplied to the throttle portions 17 and 17 'is mixed with water in the downstream central enlargement portion 18 to become an emulsion,
The emulsion flows out to the outer tube 9 through the communication hole 11,
At the same time as being ejected from the nozzle 3 to the strip 1, a part of the ejector portion 1 is provided near both ends of the inner pipe 10.
The ejector portions 15 and 1 also flow in the directions of 5 and 15 '.
Since it is designed to flow into the inner pipe 10 through the holes 16 and 16 'formed in 5', a circulation flow of emulsion is formed in the spray header.
It is possible to prevent variations in the concentration of rolling oil in the emulsion in the longitudinal direction of the spray header.

Further, in the spray headers 2 and 2 ', the rolling oil is directly supplied to the throttle portions 17 and 17' and mixed with water. Therefore, the amount of oil supplied by the oil supply control pumps 7 and 7 ' When the change is made, the changed state can be transmitted with high response to the spray headers 2, 2 ', and furthermore, the emulsion of uniform concentration can be jetted from all the nozzles. In fact, it is possible to obtain a high responsiveness that the change in the amount of oil supplied by the oil supply control pumps 7 and 7'is transmitted to the nozzles in 0.5 seconds or less, and the rolling oil concentration and the flow rate of all the nozzles are almost the same. The result was uniform.

The main structure of the rolling control device applied to this embodiment is as shown in FIG. 5 when one stand is shown. That is, various sensors (entrance tension meter 31, exit tension meter 32, load meter 33) for detecting rolling data necessary for calculating the friction coefficient are installed, and each detection signal detected by these sensors is installed. When (input side tension Tin, output side tension Tout, rolling load P) is input to the calculator 30, the actual friction coefficient is calculated by applying the measured value based on each detection signal to a predetermined arithmetic expression. .

Further, in the computer 30, when the actual friction coefficient is calculated, a deviation between the actual friction coefficient and the target friction coefficient is calculated, and the target value or the target value of the required rolling oil supply amount is calculated based on the deviation. Is calculated, and based on the result, a command signal is output to the rolling oil supply control device so that the actual amount of rolling oil supplied reaches the target value.

In the present embodiment, rolling control is performed as follows according to the flow chart shown in FIG.

First, at the time of rolling, the actual rolling data is input to the computer 30 from each of the sensors (step 110). As the rolling data, the inlet side tension Tin, the outlet side tension Tout and the rolling load P are input as shown in FIG.
Further, the computer 30 has a work roll diameter R, an inlet side plate thickness h _in , a reduction rate γ, a reduction amount Δh, a sheet width: W, an average deformation resistance: k bar, which are required for control calculation, from the upper computer 34. Target friction coefficient: μ ^* etc. is input.

When the actual rolling data and the like are input to the computer 30, the actual rolling data and the like are used here,
Actual friction coefficient μ for each stand according to the following equation (1)
Is calculated (step 112), and then the deviation from the preset target optimum friction coefficient μ ^* is calculated (step 114).

[0030]

[Equation 1] Here, R ′ = R [1 + 16 {(1-ν ² ) / Eπ} P
/ (WΔh)] ν: Poisson's ratio E: Young's modulus

The optimum (target) friction coefficient μ ^* is set by a table for each type of the material 1 to be rolled, the reduction rate, and the reduction amount, and is sent from the upper computer 34 to the computer 30 as shown in FIG. It is transmitted with the data needed for the calculation.

Next, the calculated friction coefficient deviation (μ-
μ ^* ) is used to calculate the optimum amount of rolling oil supplied to each stand where the actual friction coefficient μ matches the target value μ ^* (step 116), and the optimum pump amount can be adjusted by the upper pump rotation speed r _u The pump speed r _l can be calculated from the following (2),
It is calculated by the equation (3).

R _u = r _int × α (2) where α = 1 + (μ-μ ^* ) × [A × {(μ + μ ^* )
/ 2} ² + B × (μ + μ ^* ) / 2 + C] r _l = r _int × α × β (3) where A, B, and C are constants r _int : initial upper pump rotational speed β: vertical pump rotational speed ratio

Next, the rotation speeds of the upper and lower pumps calculated by the above equations (2) and (3) are output to each stand as a rolling oil supply amount change command signal (step 118), and the rolling oil supply amount of each stand is increased. The changing device (rolling oil supply system in FIG. 4) is operated (step 120), and the rotation speeds of the motors 8 and 8'for driving the oil supply control pumps 7 and 7'are controlled to the calculated values. .

By repeating the above processes (step 122), it becomes possible to continue rolling with the optimum friction coefficient.

In this embodiment, since the rolling oil supply amount is controlled by using the rolling oil supply system having the self-circulating spray header shown in FIG. 3, the response of the concentration change is extremely high. fast. Therefore, the control cycle can be shortened, and the accuracy of the friction coefficient control can be improved accordingly.

The results (methods of the present invention) obtained by actually applying the present embodiment to rolling are shown in the above Japanese Patent Publication No. 63-124.
6 and 7 together with the results (conventional method) when the method (1) was applied.

FIG. 6 shows the average value of the actual friction coefficient obtained for each stand and its distribution, and FIG. 7 shows the production efficiency and rolling oil basic unit.

According to the present embodiment described in detail above, since the friction coefficient can be obtained from the measured data and controlled so as to reach the target value, the actual rolling state is accurately maintained at the proper friction coefficient. It becomes possible to do. Therefore, it is possible to reduce the occurrence rates of heat streaks and chattering, improve the production efficiency, and reduce the rolling oil consumption rate.

Although the present invention has been specifically described above, the present invention is not limited to the above-mentioned embodiments, and various modifications can be made without departing from the scope of the invention.

For example, the spray header is not limited to that shown in FIG. 3, and the rolling oil supply system is not limited to that shown in FIG. Also, the number of rolling stands is not particularly limited as long as it is 1 or more.

[0042]

As described above, according to the present invention,
By maintaining the lubricity at the time of rolling in an appropriate state based on the actual rolling data and controlling the friction coefficient to be the target value, highly accurate rolling can be performed.

[Brief description of drawings]

FIG. 1 is a flowchart showing a processing procedure of an embodiment according to the present invention.

FIG. 2 is an explanatory diagram showing a schematic configuration of a continuous rolling mill applied to the embodiment.

FIG. 3 is an enlarged sectional view of a spray header applied to an embodiment.

FIG. 4 is a schematic explanatory view showing a rolling oil supply system applied to an embodiment.

FIG. 5 is an explanatory diagram showing a main part of a control system applied to the embodiment.

FIG. 6 is a diagram showing the effect of the embodiment.

FIG. 7 is another diagram showing the effect of the embodiment.

[Explanation of Codes] 1 ... Strip 2, 2 '... Spray header 3, 3' ... Nozzle 5, 5 '... Oil supply pipe 6, 6' ... Water supply pipe 7, 7 '... Oil supply control pump 9 ... Outer pipe of spray header 10 ... Inner pipe of spray header 12 ... Water supply control pump 13 ... Water supply control motor 15, 15 '... Ejector part 16, 16' ... Hole 18 ... Central enlarged part 30 ... Computer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Fumio Furukaku, 1 Kawasaki-cho, Chuo-ku, Chiba-shi, Chiba Prefecture Chiba Works, Kawasaki Steel Co., Ltd. (72) Shoji Matsumoto, 1 Kawasaki-cho, Chuo-ku, Chiba-shi, Chiba Prefecture Kawasaki Steel Co., Ltd. Chiba Steel Works (72) Inventor Koji Kawashima 1 Kawasaki-cho, Chuo-ku, Chiba City, Chiba Prefecture Kawasaki Steel Co., Ltd. Chiba Steel Works

Claims (3)

[Claims] 1. A rolling control method for rolling a material to be rolled while supplying rolling oil, wherein actual friction coefficient is calculated using actual rolling data, and the calculated actual friction coefficient becomes a target friction coefficient. A method for controlling rolling, characterized in that the supply amount of rolling oil is controlled as described above. 2. The rolling control method according to claim 1, wherein the rolling oil is supplied by using a highly responsive spray header capable of forming an emulsion by internally mixing the rolling oil and water. . 3. The spray header according to claim 2, wherein oil supplied to the central portion and water supplied from both end portions through the ejector portions are mixed on the downstream side of the central portion to form an emulsion. An inner pipe having a portion, and an inner pipe containing the inner pipe therein, and an outer pipe provided with a nozzle for injecting the emulsion discharged from the mixing portion, through a through hole formed in the ejector portion, A rolling control method characterized by using a self-circulating spray header adapted to circulate a part of the emulsion delivered to the outer tube into the inner tube.