KR101091507B1 - A method for controlling rolling pitch of wire rod - Google Patents

Abstract

An object of the present invention is to provide a wire rod pitch control method for automatically detecting the pitch time between the preceding material of the roughing mill and controlling the speed of the driving motor of the roughing mill according to the detected pitch time.

The wire rod pitch control method of the present invention comprises: a pitch automatic mode determination step of determining a pitch automatic mode selection during a general mode in which continuous rolling of the preceding material is performed using a preset pitch time TG; When the automatic pitch mode is selected, the automatic pitch mode is entered to detect the actual pitch time (TP) of the material before and after rough rolling, and the pitch correction is a deviation value between the set pitch time (TG) and the actual pitch time (TP). A pitch correction time calculating step of calculating a time TC; A rolling speed maintenance step of maintaining a current rolling speed when the pitch correction time TC is zero; A correction speed calculating step of calculating a correction speed of rolling using the pitch correction time when the correction time TC is not zero; A rolling speed correction step of controlling the rolling speed of the rough rolling stand using the correction speed; And returning to the normal mode from the normal mode return condition.

Wire Rod Continuous Rolling, Pitch Control, Speed Control, Pitch Time, Wire Rod, Heating Furnace, Extraction Roller, Control Method

Description

Wire Rod Pitch Control Method {A METHOD FOR CONTROLLING ROLLING PITCH OF WIRE ROD}

1 is a schematic diagram illustrating a typical wire rod production process.

Figure 2 is a flow chart showing a conventional wire rolling control method.

3 is a configuration diagram of a wire rod control device for carrying out the present invention.

Figure 4 is a flow chart showing a wire rod pitch control method according to the present invention.

5 is a flowchart showing a pitch correction time calculation process of the present invention.

FIG. 6 is a schematic diagram of a pitch correction time calculation process of FIG. 5.

7 is a flowchart showing a correction speed calculation and a rolling speed correction process of the present invention.

Explanation of symbols on the main parts of the drawings

1: Stand 2: Pinch Roll

3: hot material detector (HMD) 4: heating furnace extraction roller (Roller)

5: material (billet) 6: heating furnace

ST1-ST6: 1st-6th stand HMD1: 1st hot material detector

HMD2: 2nd Annual Material Detector 100: Control Panel                 

200:

The present invention relates to a rolling pitch control method applied to a wire rod rolling process, and in particular, by using a hot material detector installed at the rear end of a rough mill, the pitch time between the trailing materials is automatically detected, and according to the detected pitch time. By controlling the speed of the driving motor, it is possible to maintain a constant pitch time between the successive rolling materials, which can reduce the rolling time of the materials, and increase the output per unit time. It relates to a control method.

In general, the wire rod process is a process of extracting the material heated to a predetermined temperature with a constant extraction pitch, rolling, cooling, and packing to a predetermined size ordered by a customer, and such wire rod rolling is rough rolling mill, intermediate rough rolling mill, intermediate It consists of a finishing mill and a finishing mill.

1 is a schematic diagram illustrating a typical wire rod production process.

Looking at the general wire production process shown in Figure 1, the continuous rolling of the material (5) extracted with the extraction pitch set continuously in the furnace, briefly described for the control process of the extraction pitch in the rolling process, first, The material is detected by the hot material detector 3 (HMD) installed in front of the pinch roll 2 after being extracted from the furnace, and the controller PLC not shown is heated to the calculated control value based on the material detection signal. The extraction pitch 4 is controlled by controlling the extraction roller 4 of the furnace 6.

Figure 2 is a flow chart showing a conventional wire rod pitch control method.

Referring to FIGS. 1 and 2, a conventional method of controlling a rolling roll pitch, that is, a method of controlling a pitch time of the extraction material 5 of a heating furnace is described. After the pitch time TG is set (S11), heating is performed. The material end extracted by the two hot material detectors (3) installed in the rear end is extracted (S12). At the time when the detector 3 is turned off, the detection signal is transmitted to the controller PLC (S13).

At this time, the controller (PLC) after calculating the extraction pitch (S14), the hot pitch material by the set pitch time (TG), the rolling speed of the rolling stand (1), the material length, the driving speed of the pinch roll (2) After the sensor 3 is turned off, when sensing the upper material of the extraction roller 4 during the waiting time TD in the controller PLC (S15, S16), the extraction roller driving signal is transmitted to extract the inside of the furnace. The roller 4 is operated to perform continuous rolling. Accordingly, the material will come out of the heating furnace (S17, S18). This operation is repeated until the end (S19).

In addition, the end of the preceding material is detected by the hot material detector 3 in the control of the furnace extraction roller, and the control is started after the waiting time TD calculated as follows. Here, the waiting time (TD) is a waiting time until the start of trailing material extraction, it is calculated as in Equation 1 below.

Here, TD is the waiting time until the start of trailing material extraction, TG is the set pitch time, V1 is the roll driving speed of the rolling stand 1, and VIN is the driving speed of the furnace pinch roll 2 (Pinch Roll Low Speed). ) And LBT is the material (billet) length.

On the other hand, the pitch time calculation (ie walking beam start time) between the leading material can be calculated as follows. That is, the time T1 at which the preceding material is turned off from the hot stand detector 3 and exits the rolling stand 1 is calculated as shown in Equation 2 below, and the trailing material is placed on the rolling stand 1. The time until T2 is calculated as shown in Equation 3 below.

Here, A1D is the entry material cross section of the stand 1, and A1E is the exit material cross section of the stand 1.

According to this, if the equations 1 to 3 are used and the set pitch time TG is used, the waiting time TD until the start of trailing material extraction is calculated as in Equation 4 above.

In the conventional wire rod pitch control method as described above, in order to extract the material from the heating furnace, the starting timing of the heating furnace walking beam and the extraction roller 4 is set to keep the pitch time of the preceding material and the following material constant. To control.

However, in such a conventional control method, manual extraction should be performed at any time according to the situation of the post process, and the control reaction may be delayed due to the aging of the equipment, so that the pitch time between materials is not always constant and becomes long or short. There is a problem that occurs.

In addition, in the conventional control method, since there is no pitch time correction function, there is a problem of causing a production failure or a result of reducing the output per hour.

The present invention has been proposed to solve the above problems, and its object is to automatically detect the pitch time between the preceding and following materials by using a hot material detector installed at the rear end of the roughing mill to drive the roughing mill according to the detected pitch time. By controlling the speed of the motor, the wire rod pitch control can maintain the pitch time between the successive rolling materials which are continuously rolled, can shorten the rolling time of the materials, and increase the output per unit time. To provide a method.

In order to achieve the above object of the present invention, the wire rod pitch control method of the present invention,

A pitch automatic mode determination step of determining a pitch automatic mode selection during a general mode in which continuous rolling of the trailing material is performed using a preset pitch time set in advance;

When the pitch automatic mode is selected, a pitch correction time calculation step of entering the pitch automatic mode to detect the actual pitch time of the material before and after rough rolling and calculating the pitch correction time which is a deviation value between the set pitch time and the actual pitch time ;

A rolling speed maintenance step of maintaining a current rolling speed when the pitch correction time is zero;

A correction speed calculating step of calculating a correction speed of rolling by using the pitch correction time when the correction time is not zero;

A rolling speed correction step of controlling the rolling speed of the rough rolling stand using the correction speed; And

Normal mode return step to return to normal mode from normal mode return condition

Characterized in that it comprises a.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

3 is a configuration diagram of a wire rod control device for carrying out the present invention.

Referring to FIG. 3, a wire rod control apparatus for carrying out the present invention is installed between the fifth stand ST5 and the sixth stand ST6 of approximately 31 stands, and is near the cutter SH cutting the head of the wire rod. The first hot material detector HMD1 for detecting the start and end of the calculation of the pitch correction time in the automatic pitch mode and the first annual material detector HMD1 at a predetermined interval (for example, 3500 mm). A second annual material detector (HMD2) for detecting a return time from the automatic pitch mode to the normal mode, an operator's operation unit 100 for operation related to driving, and an operation response through the operation unit 100 And a controller 200 for controlling the speeds of the first to second stands ST1 to ST5 based on the detection signals of the first and second annual material detectors HMD1 and HMD2.

The control unit 200 performs the wire rod pitch control of the present invention, which will be described with reference to FIGS. 4 to 7.

Hereinafter, the operation and effects of the present invention will be described in detail with reference to the accompanying drawings.

Figure 4 is a flow chart showing a wire rod pitch control method according to the present invention.

3 and 4, first, in the pitch time automatic mode selection determination step (S41, S42) of the present invention, a general mode for performing continuous rolling of the trailing material using a preset pitch time (TG) previously set Determines the pitch time automatic mode selection.

In this case, the driver selects the automatic pitch mode through the operation unit 100 and inputs it to the controller 200. In this case, the controller 200 performs the control in the automatic pitch mode as follows.

Then, in the pitch correction time calculation step (S43), if the pitch automatic mode is selected, the automatic pitch is entered into the pitch automatic mode to detect the actual pitch time (TP) of the material before and after rough rolling, and the set pitch time (TG) and The pitch correction time TC, which is a deviation value from the actual pitch time TP, is calculated, which will be described below in detail with reference to FIG. 5.

Next, in the rolling speed maintaining steps S44 and S45, when the pitch correction time TC is zero, the set pitch time TG and the actual pitch time TP are the same, thereby maintaining the current rolling speed.

Next, in the correction speed calculation step S46, when the correction time TC is not zero, the correction speed of the rolling is calculated using the pitch correction time, which will be described in detail with reference to FIG. 7.

Next, the rolling speed correction step S47 controls the rolling speed of the rough rolling stand using the correction speed, and then, in the normal mode return step S48, the normal mode return condition returns to the normal mode. Here, the normal mode return condition corresponds to a point in time when the second annual material detector HMD2 installed at a predetermined interval (for example, 3500 mm) from the first annual material detector HMD1 is turned on.

5 is a flowchart showing a pitch correction time calculation process of the present invention.

Referring to FIG. 5, the pitch correction time calculating step S43 determines whether the counter set condition is determined, and if it is a counter set condition, the actual pitch time TP is determined through the pulse count operation of the driving motor of the preceding material by the counter. It calculates (S51, S52). Then, the set pitch time TG and the actual pitch time TP are compared, and the deviation value is accumulated and stored continuously to obtain the pitch time deviation value (S53). Then, it is determined whether the counter is a reset condition, and if the counter is a reset condition, the counter is reset and the pitch time deviation value is set as the correction time TC (S54, S55).

FIG. 6 is a schematic diagram of a pitch correction time calculation process of FIG. 5.

Referring to FIG. 6, the counter set condition shown in FIG. 5 is an auto-rolling mode, a manual cascade off state, a cutting machine SH standby state, during motor driving of the fifth stand ST5, At the same time, the first rolled material detector HMD1 corresponds to a state that satisfies all the turned off states.

When this counter set condition is satisfied, the counter counts the pulses of the drive motor to calculate the actual pitch time TP which is the time interval between the preceding material and the following material.

Here, when the actual pitch time (TP) calculation process is described, the first hot material detector HMD1 is turned off to measure the time interval between the preceding material and the following material while the counter set condition is satisfied. From the point of time, the actual pitch time TP is counted by the counter COUNTER, and then accumulated while continuously storing the pitch deviation value between the set pitch time TG and the actual pitch time TP. Thereafter, when the first hot material detector HMD1 is turned on, the calculated pitch deviation value is set as a pitch correction time TC, and the counter is stopped by a counter OK signal.

Here, the counter stop condition is a state that satisfies all the state of the rolling all-line auto mode, the manual cascade off state, the first rolled material detector (HMD1) during the motor driving of the fifth stand (ST5) Corresponds to

7 is a flowchart showing a correction speed calculation and a rolling speed correction process of the present invention.

Referring to FIG. 7, when the correction time is greater than zero, the correction speed calculation step S46 calculates a reduction target value of rolling using the pitch correction time, and when the correction time is less than zero, the pitch. The acceleration target value of the rolling is calculated using the correction time.

That is, when the material linear velocity pitch correction time TC is set, the material linear velocity pitch correction time is compared with "0" or not, and if the raw material linear velocity pitch correction time is 0, the current rolling speed is maintained and the pitch correction is performed. If the time is less than or greater than zero, the acceleration or deceleration target value is calculated. For example, if the pitch correction time is greater than zero, the deceleration target value is calculated. If the pitch correction time is less than zero, the acceleration target value is calculated.

Here, the acceleration / deceleration target value is calculated by the material linear velocity acceleration / deceleration application method for each stand as shown in Equation 5 below.

Here, Tref is the material running time (Sec) between the fifth stand and the sixth stand, Vref is the material reference speed (M / Sec), and VC is the pitch time error (Pitch Time Error) between the fifth stand and the sixth stand. Is the correction speed (M / Sec), TC is the pitch correction time (Sec), D is the distance between the first hot material detector (HMD1) and the second hot material detector (HMD2), and P is the speed acceleration / deceleration target ratio. (%) And P1 is a rough rolling stand motor acceleration / deceleration target value (%).

Then, in the rolling speed correction step (S47) of the present invention, when the correction time is greater than zero, the rolling speed of the rolling stand is controlled by the deceleration target value of the rolling, and when the correction time is less than zero, The rolling speed of the rolling stand is controlled by the acceleration target value.

That is, as described above, when an acceleration or deceleration command based on the acceleration / deceleration target calculation value is issued, the driving motor of the first stand is simultaneously input to the driving motor of the fifth stand to start acceleration and deceleration to reach the acceleration / deceleration target value to perform rolling. When the second hot material detector HMD2 is turned on during the rolling to the acceleration / deceleration target value, the normal mode is returned to the normal rolling speed.

The present invention as described above can overcome the limitations of the pitch time control method between materials caused by the conventional technology without the pitch time correction function, and controls the pitch time during rolling of the material extracted in the conventional method. By introducing a correction function, the first hot-burned material detector (HMD1) that detects the material after rough rolling detects the pitch time between the leading and trailing materials being rolled, and sends the signal to a controller (eg, PLC) to correct it through the controller. Calculate the time to perform, and convert it to rolling speed to accelerate and decelerate the driving speed of the rough rolling stand to the acceleration / deceleration target value, and control to reduce to the standard rolling speed when the second hot-rolled material detector (HMD2) is turned on. It is a control rolling method with a correction function to make the time constant.

According to the present invention as described above, in the rolling pitch control method applied to the wire rod rolling process, the pitch time between the preceding and following materials is automatically detected by using a hot material detector installed at the rear end of the rough mill, and according to the detected pitch time. By controlling the speed of the driving motor of the roughing mill, the pitch time between the successive rolling materials that are continuously rolled can be kept constant, the rolling time of the raw materials can be shortened, and the yield per unit time can be increased. It works.

That is, according to the above, in order to overcome the limitations generated in the pitch time control method between the conventional materials, the constant pitch time between the materials extracted by the conventional method is adjusted by the rolling speed between the materials before and after the rolling. By correcting the difference between the set pitch time and the actual pitch time, it is possible to simultaneously solve the production failure caused by the short pitch time and the decrease in the output caused by the long pitch time.

Claims (4)

A pitch automatic mode determination step (S41, S42) for determining a pitch automatic mode selection during a general mode in which continuous rolling of the trailing material is performed using a preset pitch time TG set in advance; When the automatic pitch mode is selected, the automatic pitch mode is entered to detect the actual pitch time (TP) of the material before and after rough rolling, and the pitch correction is a deviation value between the set pitch time (TG) and the actual pitch time (TP). A pitch correction time calculating step of calculating a time TC; A rolling speed maintenance step of maintaining a current rolling speed when the pitch correction time TC is zero; A correction speed calculating step of calculating a correction speed of rolling using the pitch correction time when the correction time TC is not zero; A rolling speed correction step of controlling the rolling speed of the rough rolling stand using the correction speed; And A normal mode returning step of returning from the normal mode return condition to the normal mode, The correction speed calculation step, If the correction time is greater than zero, the deceleration target value of the rolling is calculated using the pitch correction time, and if the correction time is less than zero, the wire rolling pitch for calculating the acceleration target value of the rolling using the pitch correction time. Control method. The method of claim 1, wherein the pitch correction time calculating step Calculating an actual pitch time (TP) through a pulse count operation of the driving motor of the preceding material by the counter when the counter set condition is determined by determining whether the counter set condition is met; Comparing the set pitch time (TG) with the actual pitch time (TP) and continuously accumulating and storing the deviation value to obtain a pitch time deviation value; And Determining whether the counter is a reset condition, and if the counter is a reset condition, resetting the counter to set a pitch time deviation value as a correction time TC. Wire rod pitch control method comprising a. delete The method of claim 1, wherein the rolling speed correction step When the correction time is greater than zero, the rolling speed of the rolling stand is controlled by the deceleration target value of the rolling, and when the correction time is less than zero, the wire rolling pitch which controls the rolling speed of the rolling stand by the acceleration target value of the rolling. Control method.

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