RU2147951C1 - Strip interstand tension automatic control system - Google Patents

Abstract

FIELD: rolling automation. SUBSTANCE: system has a looper with a drive from DC motor connected to the looper angle-of- rise transmitter, moment regulator unit connected to the DC motor of the looper drive, whose input is connected to the input of the limiting unit. Besides, the system has a looper extreme positions regulator unit connected to the output of the limiting unit, moment calculation unit connected to the limiting level control input of limiting unit output signal, looper angle-of-rise transmitter connected to the input of the looper extreme positions regulator unit, loop dimensions regulator unit connected to the output of the looper angle-of-rise transmitter. The system has also a stand speed governor unit connected to the output of the loop dimensions regulator unit, control unit connected to the control inputs of the moment calculation unit, loop dimensions regulator unit, control unit connected to the control inputs of the moment calculation unit and loop dimensions regulator unit. In addition, the system has a dependent lowering unit whose one information input is connected to the output of the looper position preset from the control unit, the second information output of the unit is connected to the output of the loop dimensions preset from the control unit the third information input is connected to the output of the stand speed governor (i-1), the first information output of the dependent lowering unit is connected to the preset input of the looper extreme positions unit, the other information output of the unit is connected to the preset input the loop dimensions unit, the first is connected to the output of the control unit enabling the operation of the regulators, the second control input of the unit is connected to the output of the transmitter of metal presence in the stand (i-1). EFFECT: enhanced yield of suitable rolled products due to minimization of ship expansion and reduced probability of emergency situations during rolling of the strip rear end. 4 dwg

Description

 The invention relates to automation of rolling production and can be used in systems for automatic regulation of interstand tension.

 A known system for controlling the inter-strut tension of a strip on a continuous broadband mill, comprising a loop holder with a drive from a DC motor, a loop angle sensor, a restriction unit, a torque calculation unit and a loop torque controller, loop position and loop holder position [1].

 The closest analogue to the present invention is a system for automatically controlling the tension of the strip, comprising a loop holder with a drive from a direct current motor connected to a sensor for lifting angle of the loop holder, a torque regulator block connected to a direct current motor of the loop holder drive, a loop holder of extreme positions of the loop holder connected to the input of the torque regulator , torque calculation unit connected to the input of the control of the output level of the output signal of the controller block extreme of their loop holder positions, loop holder lift angle sensor connected to the input of the loop holder extreme position controller block, loop size regulator block connected to the loop holder angle sensor output, rolling stand speed regulator block connected to the output of the loop size regulator block, the control unit connected to the control input of the calculation unit moment, the control unit is connected to the inputs of the regulator block of the extreme positions of the loop holder and the inputs of the loop size regulator block [2].

 The disadvantage of these systems is that during the rolling of the tail parts of the strips, the tension in the span and the position of the loop are not regulated. A consequence of the lack of these systems is that the geometrical dimensions of the rear end of the strip go beyond tolerance. Lack of control over the size of the loop during rolling of the rear end of the strip in the event of an excessive loop can lead to an emergency with a breakdown of the work rolls of the mill. These shortcomings are caused by the fact that at the moment the metal leaves the (i-1) stand, the jump control unit decreases the task of the extreme positions of the loop holder and the loop size regulator from the operating value to the initial position, while inhibiting the operation of the loop size regulator. Thus, during rolling of the rear end of the strip, there is no regulation of inter-strut tension, because The loop holder at this time takes its initial position, and the loop size adjuster is turned off.

 The technical result of the invention is to increase the yield of rolled products by minimizing the width of the strip and reducing the possibility of an emergency during rolling of the rear end of the strip.

 The technical result of the invention is achieved in that the system further comprises a dependent lowering unit, one information input of the dependent lowering unit is connected to the job output to the position of the loop holder from the control unit, the second information input of the dependent lowering unit is connected to the job output by the loop size from the control unit, the third the information input of the dependent lowering unit is connected to the output of the speed sensor (i-1) of the stand, the first information output of the dependent lowering unit is connected is connected to the input of the job of the regulator of extreme positions of the loop holder, the other information output of the dependent lowering unit is connected to the input of the job of the regulator of the loop size, the first control input of the dependent lowering unit is connected to the output of the control unit allowing the regulators to work, the second control input of the dependent lowering unit is connected to the output of the presence sensor metal in the (i-1) stand.

 In FIG. 1 shows a block diagram of a system for automatically controlling the inter-strut tension of a strip; in FIG. 2 is a block diagram of a moment calculation unit; in FIG. 3 is a block diagram of a control unit; in FIG. 4 is a block diagram of a dependent lowering unit.

 The system for automatically controlling the inter-strut tension of strip 1 (Fig. 1) in the inter-strut space between the i-th and (i + 1) -th stands contains a loop holder 2 driven by a DC motor 3, a torque regulator 4, a restriction block 5, an extreme 6 regulator position of the loop holder, the moment calculation unit 7, the inputs of which are connected to the adjusters (not shown) of the width B, the thickness H of the strip and the specific tension G '', the loop size adjuster 8, the rolling stand drive speed controller 9, the loop angle sensor 10, the control unit 11, at the entrance which receives signals of the presence of metal in the stand, a dependent lowering unit 12. The moment calculation unit 7 (Fig. 2) contains four multipliers 13 ... 16, an adder 17, two adjusters 18, 21 and a switch 19, as well as an element of trigonometric calculations 20. At the output 13 of the multiplier, a signal is generated proportional to the cross-section and the weight of the strip in the inter-span gap, the multiplier 14 calculates a given tension in the strip, and the multipliers 15 and 16 form a linearized characteristic independent of the lifting angle of the loop holder. The master 18 enter the value of the unbalanced moment of the loop holder. The adder 17 summarizes three components that determine the required moment on the loop holder motor, namely the moment from the weight of the strip in the gap, the unbalanced moment of the loop holder and the component going directly to create tension in the strip. The sum of these components determines the torque of the looper motor. The input from the trigonometric calculation element 20 receives a signal from the output of the loop angle sensor 10, the signal proportional to the sine of the loop angle at one output of the element 20, and the signal proportional to the cosine of the loop angle of the loop at the other output. In the initial position, the switch 19 connects the output of the unit to the setter 21, which determines the maximum moment of the loop holder. Thus, if there is no metal in the inter-span gap or the manual mode of the loop holder is selected, the loop holder moment is limited to the maximum value. The control unit 11 (Fig. 3) contains the angle adjusters 23 of the maximum and 24 initial angles for the controller of the extreme positions of the loop holder, the adjusters 25 of the working and 26 initial angles for the loop controller, two switches 27 and 28. The block operates as follows. When the strip enters the interstage gap, sensors for the presence of metal in the stands are activated, and if the automatic mode of operation of the loop holders is selected, a signal appears at the output of logic element 22, allowing the loop and torque regulators to work. In this case, the switches 27 and 28 are triggered, which issue a task to the inputs of the extreme position controllers and loops. The input to the loop controller receives a task for the working angle of rise set by the setter 25. The input of the extreme position controller receives a task for the maximum angle of rise of the loop holder set by the setter 23. The dependent lowering unit 12 (Fig. 4) contains a logic element 29, four selectors 30. ..33, two multiplication elements 34 and 35, two integral elements with output level limiting 36 and 37. The block works as follows. In the initial position, when there is no rolled strip in the gap, the selectors 30 and 32 connect a constant K2 of positive polarity of large magnitude to the input of the multiplication elements 34 and 35, a signal of positive polarity proportional to the speed of the strip, from the outputs of the multiplication elements 34 and 35 goes to the integral elements 36 and 37, the output signal of positive polarity of the integral element 36 is limited at a level equal to the maximum angle of elevation of the loop holder, the output signal of positive polarity of the integral element 37 is limited at a level equal to the working size of the loop, the selector 31 in the initial state provides the transmission of the reference signal to the position from the control unit 11 to the extreme position controller 6 of the loop holder, the selector 33 in the initial state provides the transmission of the loop size setting signal from the control unit 11 to the size regulator loop 8. At the moment the metal leaves the stand (i-1), if the regulators are enabled, the logic element 29 generates a command to switch selectors 30 ... 33, at this moment the inputs of the extreme position controller of the loop the holder 6 and the loop size regulator 8 are disconnected from the output of the control unit 11, and connected to the outputs of the integral elements 36 and 37, respectively, the selectors 30 and 32 connect the negative constants K1 and K3 to the inputs of the multiplication elements 34 and 35, respectively, at the outputs of the multiplication elements 34 and 35, negative polarity signals are generated proportional to the speed of the strip; at the outputs of the integral elements 36 and 37, a linearly falling signal from the upper limit setting to the lower limit setting with a rate proportional to scab lanes for the integral elements 36 and 37 of the lower limit of the output signal is equal to the initial setting elevation angle looper.

 The system of automatic regulation of the inter-strut tension of the strip works as follows. In the initial position, when the rolled strip is not in the gap, the loop controller 8 is turned off, at the output of the moment calculation block 7, the maximum signal that is input to the limit level control input of the restriction block 5, in the initial position, the restriction block 5 does not limit the output signal of the extreme position controller 6 , the input of the extreme position controller 6 from the dependent lowering unit 12 receives the reference signal for the initial lifting angle of the loop holder, and the second input receives a feedback signal for the position from the angle sensor looper 10. The controller unit 6 end positions looper operates in maintaining looper in a predetermined position. The loop holder is in the initial position, raised above the supports by 5-10 mm and is ready for use. When the strip enters the interstitial gap, the sensors of the presence of metal in the stands (i-1), i-th and (i + 1)-th are successively triggered. The control unit 11 logically processes the signals of the presence of metal and at the moment the strip enters the (i + 1) -th stand allows the loop controller, the moment calculation unit to work, and also increases the loop controller task to the working value, for the extreme position controller the task is set equal to the maximum . The regulator 6 of the extreme positions, working in the mode of maintaining a given angle, begins to raise the loop holder until it touches the strip, in the future it enters saturation, because setting the maximum angle is much larger than the working angle of the lifting of the loop holder with a loop. The loop controller 8 begins to generate a correction signal to the drive speed controller 9 of the (i + 1) th stand in order to obtain a predetermined loop size. At the output of block 7 of the torque regulator, a signal appears, which enters block 5, restricting the output of regulator 6 to the extreme positions of the loop holder at a level corresponding to the moment necessary to maintain the loop holder of the specified inter-stand tension of the strip. Next begins the normal process of regulation systems. The loop holder maintains a given specific tension in the strip, and the loop size regulator, acting on the stand speed regulator, maintains the loop size at a given level. When the metal leaves the (il) stand, the dependent lowering unit 12, using selectors 31 and 33, switches the reference signals to the extreme position controller of the loop holder 6 and the loop size regulator 8 from the outputs of the control unit 11 to the outputs of the integral elements 36 and 37, at the outputs of the integral elements 36 and 37, a linearly decreasing signal is formed at this moment with a rate proportional to the speed of the tail of the strip from the stand (i-1) to the i-th stand, the rate of decline of the output signal of element 36 also depends on the value of the constant K1, the rate of decline in the input signal of the element 37 also depends on the value of the constant K3, the values of the constants K1 and K3 are selected so that by the time the back end of the strip leaves the stand i, the position of the loop holder in the extreme position controller 6 of the loop holder corresponds to the initial one and the task in the loop size regulator 8 corresponds to the minimum size of the loop, changing the ratio of the constants K1 and K3, you can adjust the magnitude of the tension of the strip in the span of the gap during the process of lowering the loop holder from the working position to the original e while decreasing the metal loop size. At the moment of metal exit from the i-th stand, the control unit 11 prohibits the operation of the extreme position controller 6 and the loop size regulator 8, the dependent lowering unit 12 goes into the initial state, the reference signals at the inputs of the extreme position controller 6 and the loop size regulator 8 using selectors 31 and 33 in the block of dependent lowering 12 are switched from the outputs of the elements 36 and 37 to the outputs of the control unit 11, at the same time the selectors 30 and 32 connect the constant K2 to the inputs of the multiplication elements 34 and 35, this allows you to prepare the circuit for the next process Su lowering looper. Thus, the dependent lowering unit 12 allows you to control the interstand tension in the strip and control the size of the loop almost until the metal leaves the ith stand. Preserving the specified tension allows increasing the yield of metal by reducing the width of the strip, and controlling the size of the loop reduces the possibility of an emergency due to an excessive metal loop during rolling of the tail of the strip.

Sources of information
1. Stefanovich V. L. Automation of continuous and semi-continuous hot rolling mills. - M.: Metallurgy, 1975, p. 132.

 2. Auth. St. USSR N 1258541, Cl. B 21 B 37/06, 1986

Claims (1)

 A system for automatically controlling the inter-strut tension of the strip, comprising a loop holder with a drive from a direct current motor connected to a sensor for raising the angle of the loop holder, a torque regulator unit connected to a direct current motor of the loop holder drive, the input of which is connected to the output of the restriction block, a loop holder extreme position adjuster block, connected with the output of the lifting angle sensor of the loop holder, the output of which is connected to the input of the restriction unit, the moment calculation unit connected to the output loop holder angle sensor, the output of which is connected to the input of the restriction level output control signal of the restriction unit, a loop size control unit connected to the output of the loop holder angle sensor, rolling stand speed controller unit connected to the output of the loop size control unit, a control unit connected to the control inputs of the unit for calculating the moment and the unit for regulating the size of the loop, characterized in that it further comprises a dependent lowering unit, one information input to the second information input of the unit is connected to the output of the job by the loop size from the control unit, the third information input is connected to the output of the speed sensor (i - 1) of the stand, the first information output of the dependent lowering unit is connected to the input of the task of the controller of the extreme positions of the loop holder, another information output of the block is connected to the input of the task of the controller of the loop size, the first control input of the block of the dependent lowering is connected to the output b control box, allowing regulators to operate, the second control input of the unit is connected to the output of the metal presence sensor in the (i - 1) stand.

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