KR100985253B1 - System and method for controlling rotating speed of rolling machine work roll - Google Patents

Abstract

One aspect of the present invention relates to a roughing mill work roll rotational speed control system and control method, in particular, to prevent the table roll from being damaged by the impact of the strip on the table roll during the rough rolling process of the hot rolling mill. A system and method for controlling the rotational speed of a roll.

The rough rolling work roll rotation speed control system of the present invention includes: at least one sensor for sensing vibration by an impact applied to a table roll by a front end of the strip; An operation information database for storing rolling information of the first and second rough rolling mills; A control unit which receives a signal of the vibration due to the shock from a sensor and generates a trigger signal when the trigger signal is above a predetermined level; And receiving a trigger signal and a work roll rotation speed signal of the first and second rough rolling mills from the control unit, receiving a signal sensed by vibration from the sensor, extracting data about rolling information from the operation information database, And a server configured to evaluate the amount of vibration caused by the impact so that the controller controls the rotational speeds of the first and second rough rolling mills at a specific speed.

Rolling Mills, Rotational Speed, Work Roll, Strip, Impact

Description

System and method for controlling rotating speed of rolling machine work roll}

One aspect of the present invention relates to a roughing mill work roll rotational speed control system and control method, in particular, to prevent the table roll from being damaged by the impact of the strip on the table roll during the rough rolling process of the hot rolling mill. A system and method for controlling the rotational speed of a roll.

Hereinafter, the rolling process of the rough rolling line will be described.

1 is a perspective view of a conventional rough rolling line. As shown in FIG. 1, the rough rolling line is composed of two rough rolling mills 3 and 4, and the strip 2 from the furnace 1 is rolled in five passes in the first rough rolling mill 3. Then, it moves to the 2nd roughing mill 4 through the table roll 5, and is rolled in 3 passes.

2 is a state diagram of a case in which the conventional strip is downward (a) and a case in which the strip is normally upward (b). As shown in FIG. 2, in (b), the rotation speed of the upper work roll 3a is faster than the rotation speed of the lower work roll 3b, thereby performing normal operation.

However, in (a), the tip of the strip 2 bent downward due to the poor rotational speed of the upper and lower work rolls 3a and 3b of the roughing mill moves to the second roughing mill and impacts the table roll 5. . Since the strip 2 rolled by the first rough rolling mill 3a has a large thickness, the strip roll 2 is greatly impacted, and thus the table roll 5 is very likely to be broken.

Most of the impact forces acting on the table roll 5 are proportional to the feed rate of the strip 2, the weight of the strip 2, and the height difference due to the downward bending of the tip of the strip 2, and the table roll 5 breaks. It is a direct cause of becoming.

3 is a rolled state diagram in a conventional rough mill. As shown in FIG. 3, in general, the operating conditions in the rough rolling line should be such that the rotational speed of the upper work roll 3a of the roughing mill is faster than the rotational speed of the lower work roll 3b. The reason for this is that if the tip of the strip 2 is bent upward when the strip 2 enters the roughing mill 3 on the table roll 5, the strip 2 enters the roughing mill 3 properly. This is because the upper work roll 3a of the roughing mill 3 is not damaged and causes a great damage to the upper work roll 3a of the roughing mill 3 itself. In order to prevent this, in the initial rough rolling operation condition, the rotation speed of the upper work roll 3a should be faster than the rotation speed of the lower work roll 3b.

Of course, it is possible to adjust the rotational speed of the lower work roll (3a) of the roughing mill (3) to some extent through manual operation, if the downward bending of the front end of the strip (1) can be corrected.

However, this requires strict attention because it must wait for the moment when the strip 2 is bitten by the roughing mill 3 and perform manual operation. The adjustment of the shape of the front end of the strip 2 by manual operation is not only practically effective, but also when the rotational speed of the lower work roll 3b of the roughing mill 3 is not properly adjusted, that is, of the roughing mill 3 When the rotational speed is faster than the rotational speed of the upper work roll 3a, the tip of the strip 2 may be bent upward, which may act as an obstacle to large facilities.

One aspect of the present invention is to control the rotational speed of the lower rough work rolling mill by measuring the amount of impact applied to the table roll while moving the strip bent downward from the rough rolling mill to the roughing mill of the next position, It is an object of the present invention to provide a system and method for eliminating the risk of malfunctions that may occur when manual rotation speed is controlled.

Another aspect of the present invention is to reduce the maintenance cost of the table roll replacement by eliminating damage to the bearing or the table roll of the impacted table roll from the downwardly bent strip to maintain the optimum work roll rotation speed, It is an object of the present invention to provide a system and a method which enable the productivity improvement according to the operation.

One aspect of the present invention is a system for controlling the rotational speed of the work roll of the first and second rough mill in the process of transferring the strip rolled in the first rough mill to the second rough mill through at least one table roll. At least one sensor for sensing a vibration by an impact applied to the table roll by a front end of the strip; An operation information database storing rolling information of the first and second rough rolling mills; A control unit which receives a signal of vibration by the shock from the sensor and generates a trigger signal when the trigger signal is above a predetermined level; And receiving a trigger signal and a work roll rotation speed of the first and second rough rolling mills from the control unit, receiving a signal sensed by the impact vibration from the sensor, and receiving data regarding the rolling information from the operation information database. And a server configured to evaluate the amount of vibration caused by the impact so that the controller controls the rotational speeds of the first and second rough rolling mills at a specific speed. Provides a rotation speed control system.

In one embodiment of the present invention, the rolling information is the coil number of the strip, the number of the steel grade of the strip, the exit width for each pass of the roughing mill, the thickness of the roughing mill, the weight per unit length of the roughing mill, the work roll of the roughing mill It provides a rough rolling mill work roll rotational speed control system, characterized in that any one of the information on the rotational speed.

In another embodiment of the present invention, the server receives a signal sensed vibration by the impact, and extracts the maximum shock signal or the secondary shock signal after the shock to evaluate the amount of vibration due to the shock, characterized in that Provides a rough rolling work roll speed control system.

In another embodiment of the present invention, the server compares the signals due to the two shock vibrations measured in the table roll, designates the range of time series data, calculates the time interval, and peaks the signals due to the shock vibration. It provides a rough rolling mill work roll rotational speed control system, characterized in that any one of the value, the equivalent average impact amount, the crest factor, the maximum frequency.

According to another aspect of the present invention, there is provided a method for controlling the work roll rotational speeds of the first and second rough rolling mills in the process of transferring the strip rolled from the first rough rolling mill to the second rough rolling mill through at least one table roll. The method of claim 1, further comprising: sensing, by a sensor, vibration caused by an impact applied to the table roll by a tip of the strip; Receiving a signal of vibration by the shock from the sensor and generating a trigger signal if the trigger signal is greater than or equal to a preset level; Receiving, by a server, a signal sensed by the impact vibration from the sensor; Receiving, by the server, a trigger signal and a work roll rotation speed of the first and second rough mills from the controller; Extracting, by a server, data relating to the rolling information from an operation information database storing rolling information of the first and second rough rolling mills; And evaluating, by the server, the amount of vibration due to the impact, so that the controller controls the rotation speeds of the work rolls of the first and second rough rolling mills at a specific speed. Provides a rotation speed control method.

In another embodiment of the present invention, the server receives a signal sensing the vibration caused by the shock, and extracts the maximum shock signal or the secondary shock signal after the shock to evaluate the amount of vibration caused by the shock Provided is a method for controlling a rolling speed of a rolling mill work roll.

In another embodiment of the present invention, the server compares the signals due to the two shock vibrations measured in the table roll, designates the range of time series data, calculates the time interval, and peaks the signals due to the shock vibration. It provides a rough rolling mill work roll rotational speed control method characterized in that any one of the value, the equivalent average impact amount, the crest factor, the maximum frequency.

According to an aspect of the present invention, it is possible to eliminate the risk of malfunction that may occur when manually operating the rotational speed of the roughing mill lower work roll.

According to another aspect of the present invention, it is possible not only to reduce the maintenance cost due to the replacement of the table roll, but also to improve productivity due to stable operation.

According to another aspect of the present invention, it is possible to utilize the control of the rolling operation by providing information to the driver quickly by displaying this in real time at the same time measuring the impact amount during operation.

According to another aspect of the present invention, the impact amount measurement data during the operation can be analyzed as well as the parameters according to the operation can be utilized as the technical data for the optimal operation pattern establishment and life extension of the facility.

According to another aspect of the present invention, by minimizing the downward work of the strip end portion passing through the roughing mill can prevent the breakage of the table roll due to the impact load, it is possible to extend the life of the rolling equipment.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. However, the embodiments of the present invention may be modified into various other forms, and the scope of the present invention is not limited to the embodiments described below. Shapes and sizes of the elements in the drawings may be exaggerated for clarity, elements denoted by the same reference numerals in the drawings are the same elements.

4 is a block diagram of a rough rolling work roll rotation speed control system according to an embodiment of the present invention. As shown in FIG. 4, the rough rolling work roll rotational speed control system includes a plurality of table rolls 310 arranged in a row with the strips rolled in the first rough rolling mill 210 after being heated in the heating furnace 100. In the process of transferring to the second rough mill 220 through 320, 330, 340, 350, 360, and 370, the rotation speeds of the work rolls of the first rough mill 210 and the second rough mill 220 are controlled.

The rough rolling work roll rotation speed control system may include a first sensor 410, a second sensor 420, a controller 500, a server 700, and an operation information database 800.

The first sensor 410 and the second sensor 420 sense vibrations caused by an impact applied to the table roll by the tip of the strip. The sensing method is triggered by the amount of vibration caused by the shock sensed through the first sensor 410 provided in one table roll 330, one table roll 330 and the other table roll 350 The amount of vibration due to the shock sensed through the second sensor 350 provided in the sensing. The time for sensing the vibration due to the shock applied by the first sensor 410 and the second sensor 420 to the table rolls 330 and 350 is set to 9 to 11 seconds. Preferably, the sensing time is 10 seconds.

The operation information database 800 stores the rolling information of the first rough mill 210 and the second rough mill 220. The rolling information may be any one of the coil number of the strip, the number of the steel grade of the strip, the exit width for each pass of the rough rolling mill, the thickness of the rough rolling mill, the weight per unit length of the rough rolling mill, and the work roll rotation speed of the rough rolling mill. Can be.

The controller 500 receives a signal of vibration due to an impact from the first sensor 410 and the second sensor 420, and generates a trigger signal when the trigger signal is above a predetermined level.

The server 700 receives a trigger signal and a work roll speed signal of the first rough mill 210 and the second rough mill 220 from the control unit 500, and the first sensor 410 and the second sensor 420. Receives a signal that senses the vibration due to the impact applied to the table roll by the end of the strip, and extracts data about the rolling information from the operation information database 800 to evaluate the amount (or the amount of impact) of the vibration due to the impact The control unit 500 to control the rotational speed of the work roll of the first rough mill 210 and the second rough mill 220 at a specific speed. When the server 700 receives signals from the first sensor 410, the second sensor 420, and the control unit 500, the digital signal converted from an analog signal through an analog / digital converter (A / D) 600 is used. Receive the signal.

The driver may vibrate and roll information (coil number of the strip, number of steel grades of the strip, exit width for each pass of the roughing mill 330) due to the impact of the strip applied to the table rolls 330 and 350 through the server 700, The thickness of the roughing mill 330, the weight per unit length of the roughing mill 330, the information about the work roll rotational speed of the roughing mill 330). This rolling information is used to calculate the down rate of the strip.

When the trigger signal is received from the control unit 500, the server 700 displays the screen in any one of a status monitoring mode, a trend analysis mode, a diagnostic mode, and a data storage mode according to the evaluation of the amount of vibration caused by the shock. Display.

In addition, the server 700 receives a signal sensing the vibration caused by the shock, and extracts the maximum shock signal or the second shock signal after the impact to evaluate the amount of vibration caused by the impact.

Since the present invention has a method of acquiring a signal using only the amplitude of the amplitude, not a method of immediately acquiring a vibration signal due to an impact due to the characteristics of the field, the table rolls 330 and 350 at an actual measurement position. ), The impact signal from the table rolls 330 and 350 before impacting the same.

Therefore, the pre-trigger method cannot be used directly, and thus the pre-trigger method is used indirectly. The maximum impact since the rotational speed of the table rolls 330, 350 is constant because of the vibration signals caused by the impacts on the table rolls 330, 350 before colliding with the table rolls 330, 350 at the actual measurement position. It is possible to extract the vibration signal due to the effective impact on the vibration value, which will be described in detail with reference to FIG. 5.

In addition, the server 700 compares the signals due to the two shock vibrations measured by the table rolls 330 and 350, designates the range of time series data, calculates the time interval, and calculates the peak value of the signal due to the shock vibration, Calculate any one of the equivalent average impact, crest factor, and maximum frequency.

The rough rolling work roll rotation speed control system is characterized in that the user can continue to operate without interruption until the user stops the control operation through the server.

5 is a graph for explaining the measurement of the vibration signal by the effective shock with respect to the maximum impact vibration value of the present invention. Looking at Figure 5 with Figure 4 as follows. 5 is a graph showing the impact amount (g) according to time (t), the sensing method according to the present invention is the vibration of the vibration caused by the shock sensed through the first sensor 410 provided in one table roll 330 Using the amount as a trigger, the amount of vibration due to the shock sensed by the second sensor 350 provided in one table roll 330 and the other table roll 350 is sensed. The time for sensing the vibration due to the shock applied by the first sensor 410 and the second sensor 420 to the table rolls 330 and 350 is set to 9 to 11 seconds. Preferably, the sensing time is 10 seconds.

The measurement of the time of acquiring the amount of vibration through sensing is an experimental determination of the range of time series signals in which the vibration due to the shock is sufficiently attenuated and lost as a result of repeated experiments of the amount of vibration due to the shock.

In the method of measuring the vibration signal, the vibration caused by the shock in the table roll 330 and the table roll 350 is measured using the vibration caused by the shock in the table roll 330. The trigger level is determined experimentally, but is currently set to 3g as the initial value, but can be adjusted arbitrarily. The sampling frequency is 2 kHz, allowing analysis up to 1 kHz in the frequency domain.

Since the mass of the rolled steel sheet is very large and empirically the natural frequency range is 300 kHz, it is judged that the maximum frequency is sufficient to 1 kHz.

Based on the data showing the impact amount g according to the time t to date, the interval of the vibration signal due to the impact between the table rolls is about 0.21 seconds, about 0.034 seconds to the left based on the maximum peak value, The vibration signal caused by the impact including the signal of 0.184 seconds to the right is referred to as the vibration signal caused by the effective shock.

As such, the two time intervals can be changed variably in the present invention, and the inventors have invented a table roll impact data analyzer used in a server as a tool for analyzing and determining them. This program can be executed independently of the main program, and can read the vibration signal data due to the impact and analyze the enlargement, reduction analysis and the amount of the vibration signal due to the impact repeatedly.

6 is a graph of the impact data analysis applied to the table roll of the present invention. As shown in FIG. 6, the two graphs on the left side are graphs showing the impact amount Acc with time, and the two graphs on the right side are graphs showing the impact amount Acc with the frequency Freq.

The function of the table roll shock data analyzer compares signals from two shock vibrations measured on two table rolls, calculates the time interval by specifying the range of time series data, and calculates the peak value, equivalent average impact amount, crest factor, and maximum frequency. Calculate

When the leading edge of the strip impacts the table roll, the natural frequency band of the table roll is analyzed as a band around 300 Hz, and the impact vibration is the excitation form transmitted in the group unit of the table roll when the strip strikes the measured table roll. Is caused by. Since the occurrence of such an impact is intermittent, the value obtained by reading the amplitude is integrated as the amount of impact vibration, and the average value of the squared value of the measurement time is the average amount of impact.

의 속력으로 충돌한 후

의 속도로 튀어나갈 때, 임의의 물체가 받는 힘은 도 7에 도시된 바와 같이 시간에 따른 충격력의 그래프로 나타낼 수 있다. 이때, 물체 A가 물체 B와 충돌하는 시간을

라고 하면, 수학식 1 내지 수학식 5와 같은 관계식이 얻어진다.7 is a graph for explaining the impact amount calculation method of the present invention. Any object A with mass m is

After crashing at

When bouncing at a speed of, the force received by any object can be represented as a graph of impact force over time as shown in FIG. 7. At this time, the time that object A collides with object B

In this case, relational expressions such as Equations 1 to 5 can be obtained.

,

,

,

,

I, a,

,

는 각각 힘, 가속도, 충돌 후의 운동량, 충돌 전의 운동량, 운동량의 변화량, 충격량, 가속도, 평균 충격량, 등가 평균 충격량이다. 도 7에서 빛금친 부분의 넓이는 충격량을 나타내며, 이는 직사각형의 넓이와도 같다.here,

,

,

,

,

I, a,

,

Are the force, acceleration, momentum after impact, momentum before impact, amount of momentum change, impact amount, acceleration, average impact amount, and equivalent average impact amount, respectively. In FIG. 7, the area of the glazed portion represents the impact amount, which is equal to the area of the rectangle.

When the equation 1, which is a force expression, is modified, it can be expressed as Equation 2, which represents the impact amount g as the product of the force and the time t acted on. That is, the impact amount is equal to the amount of change in the momentum, and when Equation 2 is expressed as an integral expression in the time interval [t1, t2] with respect to the acceleration a, it is as Equation 3. In order to evaluate the magnitude of the acceleration, the acceleration is squared to obtain an average impact amount, as shown in Equation 4.

In the present invention, since it is an object to evaluate the impact amount relatively, the average impact amount is evaluated by defining an equivalent average impact amount obtained by dividing the mass m as shown in Equation (5).

8 is a graph showing the relationship between the impact amount and the impact force of the present invention.

에서의 충격량(F

)를 나타낸다.When the object X is freely dropped on the ground having the material A and the material B, the change in the force acting on the object X according to the time (t) is shown in (a). The area of the rectangular rectangle shined in (a) is the time interval.

Impact at (F

).

As in (b), if the time it takes for the object X to fall to the ground with materials A and B respectively and completely stops is t ₁ and t ₂ , then the more force until it falls to the ground with material A and stops This takes more time to fall to the ground with material B and stop. Therefore, the areas S ₁ and S ₂ representing the respective shock amounts are equal.

9 is a screen of the state monitoring mode according to the evaluation of the amount of vibration by the impact of the present invention. It is a screen of the status monitoring mode (monitor mode) that displays the rolling material information, the vibration signal and the impact amount evaluation value due to the obtained impact on the screen in real time.

10 is a screen of a trend analysis mode according to the evaluation of the amount of vibration due to the impact of the present invention. As the screen of the trend mode, the peak value and the shock vibration value show the change of data for the time from 7 o'clock of the day to 7 o'clock of the next day, and the crest factor and the maximum frequency value update the data of the last month. Draw a trend analysis graph and update the data each time new data is acquired.

11 is a screen of the diagnostic mode according to the evaluation of the amount of vibration by the impact of the present invention. Diagnosis Mode As a screen, the diagnostic mode displays the rolled material information and the impact amount in a tabular form on the upper side. Below it, the spectrum data for the selected measurement information and the data for the last month are shown in a distribution chart in alignment with the tensile strength of the material information.

12 is a screen of the data storage mode according to the evaluation of the amount of vibration due to the impact of the present invention. The screen of the data saving mode is a secondary function, which reads stored data and analyzes the spectrum of waveforms and frequencies over time.

The present invention is not limited by the above-described embodiment and the accompanying drawings. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims, .

1 is a perspective view of a conventional rough rolling line.

2 is a state diagram of a case in which the conventional strip is downward (a) and a case in which the strip is normally upward (b).

3 is a rolled state diagram in a conventional rough mill.

4 is a block diagram of a rough rolling work roll rotation speed control system according to an embodiment of the present invention.

5 is a graph for explaining the measurement of the vibration signal by the effective shock with respect to the maximum impact vibration value of the present invention.

6 is a graph of the impact data analysis applied to the table roll of the present invention.

7 is a graph for explaining the impact amount calculation method of the present invention.

8 is a graph showing the relationship between the impact amount and the impact force of the present invention.

9 is a screen of the state monitoring mode according to the evaluation of the amount of vibration by the impact of the present invention.

10 is a screen of a trend analysis mode according to the evaluation of the amount of vibration due to the impact of the present invention.

11 is a screen of the diagnostic mode according to the evaluation of the amount of vibration caused by the impact of the present invention.

12 is a screen of the data storage mode according to the evaluation of the amount of vibration due to the impact of the present invention.

                 <Explanation of symbols for the main parts of the drawings>

100: heating furnace 210: the first rough mill

220: second rough mill

Table Roll: 310, 320, 330, 340, 350, 360, 370

410: first sensor 420: second sensor

500 control unit 600 A / D converter

700: server 800: operation information database

Claims (9)

In the system for controlling the work roll rotational speed of the first and the second rough mill in the process of transferring the strip rolled in the first rough mill to the second rough mill through at least one table roll, At least one sensor for sensing vibration by an impact applied to a tip end of the strip by the table roll; An operation information database storing rolling information of the first and second rough rolling mills; A control unit which receives a signal of vibration by the shock from the sensor and generates a trigger signal when the trigger signal is above a predetermined level; And Receives a trigger signal and a work roll speed signal of the first and second rough mill from the control unit, receives a signal sensed by the vibration from the sensor from the sensor, the data about the rolling information from the operation information database Extracting, evaluating the amount of vibration caused by the impact so that the controller controls the rotational speeds of the first and second rough rolling mills to a specific speed; Rough rolling mill work roll rotational speed control system comprising a. The method of claim 1, The rolling information is any one of the coil number of the strip, the number of the steel grade of the strip, the exit width for each pass of the roughing mill, the thickness of the roughing mill, the weight per unit length of the roughing mill, the information about the work roll rotation speed of the roughing mill Rough rolling mill work roll rotational speed control system, characterized in that. The method of claim 1, Sensing the vibration due to the impact applied to the table roll by the tip of the strip triggers the amount of vibration caused by the shock sensed by any one of the two table rolls, respectively, to the two table rolls. Rough rolling mill work roll rotational speed control system, characterized in that for sensing the amount of vibration caused by the shock sensed through the provided sensor. The method of claim 3, The time for sensing the vibration due to the impact applied to the table roll by the sensor is a rolling mill work roll rotation speed control system, characterized in that 9 to 11 seconds. The method of claim 1, The server receives a signal sensed by the vibration of the impact, and extracts the maximum impact signal or the second impact signal after the shock to evaluate the amount of vibration caused by the shock rolling mill work roll rotation control system. The method of claim 1, The server compares the signals due to the two impact vibrations measured in the table roll, designates the range of time series data, calculates the time interval, and calculates the peak value, equivalent average impact amount, crest factor, maximum of the signal due to the impact vibration. A rough rolling work roll speed control system, characterized in that for calculating any one of the frequencies. In the method of controlling the work roll rotational speed of the first and the second rough mill in the process of transferring the strip rolled in the first rough mill to the second rough mill through at least one table roll, Sensing, by a sensor, vibration caused by the impact of the leading end of the strip to the table roll; Receiving a signal of vibration by the shock from the sensor and generating a trigger signal if the trigger signal is greater than or equal to a preset level; Receiving, by a server, a signal sensed by the impact vibration from the sensor; Receiving, by the server, a trigger signal and a work roll rotation speed of the first and second rough mills from the controller; Extracting, by a server, data relating to the rolling information from an operation information database storing rolling information of the first and second rough rolling mills; And Evaluating, by the server, the amount of vibration caused by the impact, so that the controller controls the rotational speeds of the first and second rough rolling mills at a specific speed; Rough rolling mill work roll rotational speed control method comprising a. The method of claim 7, wherein The server receives a signal sensed by the vibration of the impact, and extracts the maximum shock signal or the second impact signal after the impact to evaluate the amount of vibration caused by the impact rolling mill, characterized in that for evaluating the vibration. The method of claim 7, wherein The server compares the signals due to the two impact vibrations measured in the table roll, designates the range of time series data, calculates the time interval, and calculates the peak value, equivalent average impact amount, crest factor, maximum of the signal due to the impact vibration. Rough rolling mill work roll rotation speed control method, characterized in that for calculating any one of the frequencies.

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