JPH08332520A - Tension control system in steel process line - Google Patents

Abstract

PURPOSE: To obtain a reference control current for controlling the tension of a steel varying in accordance with the state of the steel and a liquid in a liquid bath so as to be a target value. CONSTITUTION: A vertical load Pv of a pillar 14 is detected by a vertical load detecting means 15. An input side tension Pi and an output side tension Po of the steel 3 are presumed by the first presuming means 16 based on the vertical load Pv and a current (i) flowing through the third motor 12. An exit side load To is presumed by the second presuming means 17 based on the input side tension Pi, the output side tension Po and an entrance side tension Ti detected by a tension detecting means 8. The reference control current (ia) for a current control means 13 is decided by a control current operation means 18 based on the exit side tension To, the output side tension Po, an objective exit side tension To' and an objective output side tension Po'.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tension control system for controlling the tension of steel products running in a steel process line.

[0002]

2. Description of the Related Art FIG. 13 is a schematic configuration diagram of a conventional tension control system. In FIG. 13, reference numeral 1 denotes a bridle roll for tension generation for generating tension in a steel material 3 traveling in a steel process line, 2 denotes a bridle roll for reference speed for causing the steel material 3 to travel at a reference speed, and 4 for tension generation. Liquid 4a for cooling running steel material 3 between bridle roll 1 and bridle roll 2 for reference speed
Is stored in the liquid tank, 5 is a direction changing roll for changing the traveling direction of the steel material 3 in the liquid tank 4, 6 is a first electric motor for driving the tension generating bridle roll 1,
Is a current control means for controlling the current flowing through the first electric motor 6, 8 is a tension detecting means for detecting the tension of the steel material 3 on the inlet side of the liquid tank 4, and 9 is based on the tension detected by the tension detecting means 8. Tension control current output means for giving a reference control current to the current control means 7, 10 is a second electric motor for driving the bridle roll 2 for reference speed, and 11 is a second electric motor 10.
, 12 is a third electric motor for driving the direction changing roll 5, and 13 is a current control means for controlling a current flowing through the third electric motor 12.

FIG. 14 is a view for explaining the tension and the like in the vicinity of the direction changing roll 5 in FIG. In FIG. 14, Pi is the input side tension, Po is the output side tension, Pv is the vertical load, r is the radius of the direction changing roll 5, and θτ is the angle formed by the steel material 3 with respect to the perpendicular. Details of these will be described later.

Next, the operation will be described. The tension of the steel material 3 on the inlet side of the liquid tank 4 (tension on the inlet side) is Ti, and the liquid tank 4 is
The tension of the steel material 3 on the exit side (exit tension) is To. Further, the tension (input side tension) of the steel material 3 that pulls the direction change roll 5 in the inlet side direction of the liquid tank 4 is Pi, and the tension of the steel material 3 that pulls the direction change roll 5 in the outlet side direction of the liquid tank 4 (output The side tension) is Po. Further, the frictional force generated between the steel material 3 and the liquid 4a in the inlet side direction of the liquid tank 4 of the direction changing roll 5 is FLi, and the steel material 3 in the outlet side direction of the liquid tank 4 of the direction changing roll 5 is The frictional drag force generated with the liquid 4a is FLo. In the control of the entrance side tension Ti performed between the bridle rolls 1 and 2, when the steel material 3 passes through the liquid tank 4, the frictional drag force (that is, in-liquid resistance) FLi, FLo between the steel material 3 and the liquid 4a. Therefore, the output side tension To is greater than the input side tension Ti by the frictional drag force FL.
It becomes larger by i and FLo.

However, when the frictional drag forces FLi and FLo are large, the exit side tension To becomes excessive and the steel material 3 may be broken. Therefore, in order to prevent this, the third electric motor 12 is provided to drive the direction changing roll 5 to lower the output side tension Po and thus prevent the output side tension To from becoming excessive. On the other hand, if the output-side tension Po is made too low, the running of the steel material 3 in the liquid tank 4 becomes unstable. However, the frictional drag force between the steel material 3 and the liquid 4a and the frictional drag force between the direction changing roll 5 and the liquid 4a include uncertain factors, and based on the inlet tension Ti, the outlet tension To and the output tension The side tension Po is calculated to calculate the current control means 1
It was not possible to calculate the appropriate reference control current of No. 3 (current for appropriately controlling the third electric motor 12). Therefore, conventionally, the reference control current of the current control means 13 has been determined by trial and error.

[0006]

Since the conventional tension control system is constructed as described above, the reference control current of the current control means 13 must be determined by trial and error.
A lot of time is required for the setting. Further, the reference control current is the steel material 3, the direction changing roll 5, and the liquid tank 3.
The problem that the steel material 3 becomes unstable in running because it cannot automatically respond to the state change of the liquid 3a in the inside, and the steel material 3 breaks especially when the steel material 3 on the outlet side of the liquid tank 4 exceeds the allowable tension. was there.

The present invention has been made in order to solve the above-mentioned problems, and relates to the outlet tension of the steel material on the outlet side of the liquid tank and the steel material for pulling the direction change roll in the outlet direction of the liquid tank. The output side tension is dynamically estimated, and the reference control current is changed to the electric motor of the direction change roll to control the output side tension and the output side tension that change according to the state of the steel and the liquid in the liquid tank to the target values. It is an object to obtain a tension control system in a steel process line which can be applied to a controlling current control means.

[0008]

A first invention is a vertical load detecting means 15 for detecting a vertical load Pv of a column 14 supporting a direction changing roll 5, a vertical load Pv thus detected and a third electric motor. An input side tension Pi of the steel material 3 for pulling the direction change roll 5 in the inlet side direction of the liquid tank 4 and a steel material 3 for pulling in the outlet side direction of the liquid tank 4 based on the current i flowing in 12
Of the output side tension Po, the estimated input side tension Pi, the output side tension Po, and the tension of the steel material 3 on the inlet side of the liquid tank 4 detected by the tension detecting means 8. Steel material 3 on the outlet side of the liquid tank 4 based on a certain inlet side tension Ti
Second estimating means 1 for estimating the outlet tension To, which is the tension of the
7, the estimated output side tension To, the output side tension Po, the preset target output side tension To ′ and the target output side tension P
reference control current i to the current control means 13 based on
The control current calculating means 18 for determining a is provided.

The second invention is a strain detecting means 2 for detecting the strains ε1 and ε2 of the column 14 which supports the direction changing roll 5.
0, 21, load calculation means 22 for calculating the vertical load Pv and horizontal load Ph of the column 14 based on the detected strains ε1, ε2, and based on the calculated vertical load Pv and horizontal load Ph. And the liquid tank 4 and the input side tension Pi of the steel material 3 for pulling the direction changing roll 5 toward the entrance side of the liquid tank 4.
First estimating means 23 for estimating the output side tension Po of the steel material 3 pulled in the output side direction and the estimated input side tension P described above.
i, the output side tension Po, and the inlet side tension Ti, which is the tension of the steel material 3 on the inlet side of the liquid tank 4 detected by the tension detector 8, are the tension of the steel material 3 on the outlet side of the liquid tank 4. Side tension To
Current estimating means 17 based on the estimated output side tension To, the output side tension Po, and the preset target output side tension To ′ and target output side tension Po ′. Control current calculation means 19 for determining the reference control current ia to the control current ia.

In a third aspect of the present invention, the direction changing roll 51 has a hollow structure, and the high pressure fluid such as air is filled in the hollow, and the pressure of the high pressure fluid is detected to support the direction changing roll 51. The load conversion means 24 for calculating the vertical load Pv of 14 and the direction change roll 51 is pulled toward the inlet side of the liquid tank 4 based on the calculated vertical load Pv and the current i flowing in the third electric motor 12. A first estimating means 16 for estimating the input-side tension Pi of the steel material 3 and the output-side tension Po of the steel material 3 pulled in the output-side direction of the liquid tank 4, and the estimated input-side tension Pi, output-side tension Po and tension Secondly estimating the outlet tension To, which is the tension of the steel material 3 on the outlet side of the liquid tank 4, based on the inlet tension Ti, which is the tension of the steel material 3 on the inlet side of the liquid tank 4 detected by the detection means 8. Estimating means 17 of
Control current for determining the reference control current ia to the current control means 13 based on the estimated output side tension To, output side tension Po, and preset target output side tension To 'and target output side tension Po'. The calculation means 13 is provided.

A fourth invention is, in the constitution of the first invention, the second invention or the third invention, the input side tension of the steel material 3 for pulling the direction changing roll 5 or 51 in the inlet side direction of the liquid tank 4. When the difference between Pi and the output side tension Po of the steel material 3 that pulls the direction changing roll 5 or 51 in the exit side direction of the liquid tank 4 becomes a predetermined value or more, the reference control current ia to be output is limited within a predetermined range. It is characterized in that a limiter is provided in the control current calculation means 19.

[0012]

In the first aspect of the invention, the vertical load detecting means 15 detects the vertical load Pv of the column 14, and the first estimating means 16 determines the steel material based on the vertical load Pv and the current i flowing through the third electric motor 12. The input side tension Pi and the output side tension Po of No. 3 are estimated. The second estimating means 17 estimates the outlet tension To based on the input tension Pi, the output tension Po, and the inlet tension Ti detected by the tension detecting means 8. The control current calculation means 18 calculates the output side tension To, the output side tension Po, and the target output side tension T.
The reference control current ia to the current control means 13 is determined based on o'and the target output side tension Po '. Therefore, the reference control current ia is given to the current control means 13 in order to control the output side tension To and the output side tension Po that change according to the states of the steel material 3 and the liquid 4a in the liquid tank 4 to the target values,
This causes the third electric motor 12 to rotate the direction changing roll 5 at the target speed.

In the second invention, the distortion detecting means 20,
21 detects the strains ε1 and ε2 of the column 14, and the load calculating means 22 calculates the vertical load Pv of the column 14 based on the strains ε1 and ε2.
And the horizontal load Ph. The first estimating means 23 estimates the input side tension Pi and the output side tension Po of the steel material 3 based on the vertical load Pv and the horizontal load Ph. The second estimating means 17 is based on the input side tension Pi, the output side tension Po, and the input side tension Ti detected by the tension detecting means 8, and the output side tension T.
Estimate o. The control current calculation means 19 determines the reference control current ia to the current control means 13 based on the output side tension To, the output side tension Po, the target output side tension To ′ and the target output side tension Po ′. Therefore, the reference control current ia is applied to the current control means 13 in order to control the output side tension To and the output side tension Po, which change according to the states of the steel material 3 and the liquid 4a, to the target values, whereby the third electric motor is provided. 12 rotates the direction changing roll 5 at a target speed.

In the third invention, the direction changing roll 5
1 has a hollow structure, and the high pressure fluid such as air is filled in the hollow. The load conversion means 24 detects the pressure of the high-pressure fluid and calculates the vertical load Pv of the column 14. The first estimating means 16 estimates the input side tension Pi and the output side tension Po of the steel material 3 based on the vertical load Pv and the current i flowing through the third electric motor 12. The second estimating means 17 determines the input side tension Pi.
The output side tension To is estimated based on the output side tension Po and the input side tension Ti detected by the tension detecting means 8. The control current calculation means 18 determines the reference control current ia to the current control means 13 based on the output side tension To, the output side tension Po, the target output side tension To ′ and the target output side tension Po ′. Therefore, the reference control current ia is applied to the current control means 13 in order to control the output side tension To and the output side tension Po, which change according to the states of the steel material 3 and the liquid 4a, to the target values, whereby the third electric motor is provided. 12 rotates the direction changing roll 5 at a target speed.

In the fourth invention, the control current calculation means 1
When the difference between the input-side tension Pi and the output-side tension Po exceeds a predetermined value, the limiter 9 limits the reference control current ia within a predetermined range by a limiter. As a result, the current control means 13 reduces the torque of the third electric motor 12. Therefore, the torque of the direction changing roll 5 is reduced.

[0016]

【Example】

Example 1. 1 is a schematic configuration diagram of a tension control system according to a first embodiment of the present invention. In FIG. 1, components corresponding to those shown in FIG. 13 are designated by the same reference numerals, and their description will be omitted. In FIG. 1, 15 is a vertical load detecting means for detecting the vertical load Pv of the column 14 supporting the direction changing roll 5, and 16 is a vertical load Pv detected by the vertical load detecting means 15 and a current flowing through the third electric motor 12. Based on i and i, the input side tension Pi of the steel material 3 pulling the direction changing roll 5 in the inlet side direction of the liquid tank 4 and the output side tension Po of the steel material 3 pulling in the outlet side direction of the liquid tank 4 are estimated. Estimating means 17, 17 is an input side tension Pi which is estimated by the first estimating means 16, an output side tension Po, and an inlet side tension Ti which is the tension of the steel material 3 on the inlet side of the liquid tank 4 detected by the tension detecting means 8. Second estimating means for estimating the outlet tension To, which is the tension of the steel material 3 on the outlet side of the liquid tank 4, based on the above, and 18 is the outlet tension To estimated by the second estimating means 17 and the first tension. Output side tension Po estimated by the estimation means 16 and preset A control current calculation means for determining a reference control current ia to the current control means 13 a 'and the target output side tension Po' target exit side tension To based on the.

FIG. 2 is a view for explaining the tension of the steel material in the vicinity of the direction changing roll 5 in FIG. In FIG. 2, Pi is the tension on the input side, Po is the tension on the output side, Pv is the vertical load, θ is the angle made by the steel material on the input side with respect to the vertical line, τ is the angle made by the steel material on the output side with respect to the vertical line, and r is for direction change. Roll 5
Indicates the radius of.

The third is a calculation block diagram of the control current calculation means 18 in FIG. This control current calculation means 18 is a subtraction circuit 181 that calculates the deviation between the target output side tension To ′ and the output side tension To described above, and a subtraction that calculates the deviation between the target output side tension Po ′ and the output side tension Po. A circuit 182, a weighting circuit 183 for weighting the above deviations by coefficients K1 and K2, an adder circuit 184 for taking the sum of the weighted deviations, and a direction of the sum to convert the sum of the deviations into torque. A multiplication circuit 185 that multiplies the radius r of the conversion roll 5, a division circuit 186 that divides the torque by a torque constant Kt to convert the torque into a current, and a PI that performs PID compensation on the converted current and outputs a reference control current ia.
And a D compensation circuit 187.

The PID compensation circuit 187 is a P (proportiona
l) operation, I (integral) operation, and D (derivative) operation. The P motion means a proportional motion in which the smaller the deviation, the smaller the manipulated variable, and the larger the deviation, the larger the manipulated variable accordingly. If only proportional control is performed on a controlled object having self-balancing property, a certain deviation will eventually remain with respect to the target value or step change of the disturbance. This is called steady deviation. The I operation means an integration operation for removing a steady deviation by including a term proportional to the integral of the deviation in the control law. The D operation is a differential operation in which a term proportional to the differential of the deviation is also included in the control law in order to improve the control characteristics by reflecting the trend of the increase or decrease of the deviation in the determination of the manipulated variable. The control law means a method of determining the manipulated variable from the target value, the observed amount, and the measurable disturbance.

As the PID control, the differential preceding PID control in which the differentiation of the target value is stopped and the differential action works only on the observed amount, and the proportional action and the differential action act only on the observed amount・ Differential preceding PID control,
PID control with a gap provided with a certain kind of dead zone, PID control with two deviations in which the dead zone part is replaced by a certain calculation, to compensate for fluctuations in the characteristics of the controlled object without fixing the proportional gain, integration time or derivative time. In addition, variable parameter PID control that changes according to the situation, feed-forward combined PID control that adds a manipulated variable regardless of deviation, Smith-compensation PID control, decoupling PID control, and the like are known.

Next, the operation of the first embodiment will be described with reference to FIGS. Assuming that the torque constant of the third electric motor 12 is Kt and the radius of the direction changing roll 5 is r, the current i flowing through the third electric motor 12 can be calculated by the following equation due to the couple balance around the axis of the direction changing roll 5. It is expressed as 1.

[0022]

[Equation 1]

Further, the vertical load Pv is expressed by the following equation 2 according to the balance of the vertical force of the direction changing roll 5.

[0024]

[Equation 2]

The following equation 3 is obtained from the above equations 1 and 2, and the input side tension P is calculated by the equation 3 in the first estimating means 16.
Estimate i and the output side tension Po.

[0026]

(Equation 3)

On the other hand, the inlet side tension Ti and the outlet side tension T of the liquid tank 4
between o and the in-liquid resistance FLi (in-liquid resistance of the steel material 3 at the in-liquid traveling distance Li in FIG. 1) and the in-liquid resistance FLo (in-liquid resistance of the steel material 3 at the in-liquid traveling distance Lo): There is a relation of Expression 4 of

[0028]

[Equation 4]

Here, the liquid resistances FLi and FLo are approximately calculated.
When it is considered that is proportional to the running distances Li and Lo in the liquid, it is represented by the following Expression 5.

[0030]

(Equation 5)

By rearranging the above equations 4 and 5, the following equation 6 is obtained.

[0032]

(Equation 6)

The second estimating means 17 estimates the output side tension To according to the above equation (6).

In the control current calculating means 18, the target outlet tension To 'and the outlet tension To' estimated by the second estimating means 17 are calculated.
The subtraction circuit 181 obtains the output side tension deviation which is the deviation between the target output side tension Po ′ and the first estimating means 16
The output side tension deviation, which is the deviation from the output side tension Po estimated by the above, is obtained by the subtraction circuit 182, the above respective deviations are weighted by the coefficients K1 and K2 by the weighting circuit 183, and the weighted deviations are added by the addition circuit 184. Then, the added deviation is multiplied by the radius r of the direction changing roll 5 by the multiplication circuit 185 to obtain the torque, and the division circuit 186 divides the torque by the torque constant Kt to obtain the current. After that, the reference control current ia is output through the PID compensation circuit 187.

According to the first embodiment described above, the reference control current is used in order to control the output side tension To and the output side tension Po, which change according to the state of the steel material 3 and the liquid 4a in the liquid tank 4, to the target values. ia can be given to the current control means 13,
As a result, the third electric motor 12 rotates the direction changing roll 5 at the target speed, so that stable traveling of the steel material 3 can be realized, and breakage of the steel material 3 on the outlet side of the liquid tank 4 can be prevented.

Example 2. FIG. 4 is a schematic configuration diagram of a tension control system according to the second embodiment of the present invention. 4, the components corresponding to those shown in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted. In FIG. 4, reference numeral 19 denotes the outlet tension To estimated by the second estimating means 17, the output tension Po estimated by the first estimating means 16, the preset target outlet tension To ′ and the target output side. When the reference control current ia to the current control means 13 is determined based on the tension Po ′ and the difference between the input side tension Pi and the output side tension Po estimated by the first estimating means 16 becomes a predetermined value or more. , A control current calculation means for limiting the output reference control current ia within a predetermined range.

FIG. 5 is a diagram for explaining the tension of the steel material in the vicinity of the direction changing roll 5 in FIG. In FIG. 5, Pi is the tension on the input side, Po is the tension on the output side, Pv is the vertical load, θ is the angle made by the steel material on the input side with respect to the vertical line, τ is the angle made by the steel material on the output side with respect to the vertical line, and r is for direction change. Roll 5
Indicates the radius of.

FIG. 6 is a calculation block diagram of the control current calculation means 19 in FIG. The control current calculation means 19 is a subtraction circuit 181 that calculates the deviation between the target output side tension To ′ and the output side tension To described above, and a subtraction that calculates the deviation between the target output side tension Po ′ and the output side tension Po. A circuit 182, a weighting circuit 183 for weighting the respective deviations by coefficients K1 and K2, an adding circuit 184 for summing the weighted deviations, and a direction change to the sum in order to convert the sum of the deviations into torque. A multiplication circuit 185 for multiplying the radius r of the work roll 5, a division circuit 186 for dividing the torque into a current by a torque constant Kt, and a PID for compensating the converted current and outputting a reference control current ia.
ID compensation circuit 187, input side tension Pi and output side tension P
a subtraction circuit 188 for taking the deviation from o, a magnitude judgment circuit 189 for judging the magnitude of the deviation, and a limiter 190 for limiting the reference control current ia within a predetermined range when the judged deviation becomes a predetermined value or more. I have it.

Next, the operation of the second embodiment will be described with reference to FIGS. The description of the same parts as those of the first embodiment will be omitted. Control current calculation means 18
Then, the subtraction circuit 181 obtains the output-side tension deviation, which is the deviation between the target output-side tension To ′ and the output-side tension To estimated by the second estimating means 17, and also calculates the target output-side tension Po ′ and the first output-side tension Po ′. The subtraction circuit 182 obtains the output side tension deviation which is the deviation from the output side tension Po estimated by the estimation means 16, the weighting circuit 183 weights each of the above deviations by the coefficients K1 and K2, and the weighted deviations are calculated. The addition circuit 184 performs addition, and then the added deviation is multiplied by the radius r of the direction changing roll 5 by the multiplication circuit 185 to obtain torque, and the division circuit 186 divides the torque by the torque constant Kt to obtain the current. After that, it is output as the reference control current ia through the PID compensation circuit 187. Where steel material 3
When a large torque is generated in the third electric motor 12 while the vehicle is traveling, and the deviation between the input side tension Pi and the output side tension Po near the liquid tank 4 becomes a predetermined value or more, the control current calculation means 19 causes the limiter. The reference control current ia is limited by 190 within a predetermined range. As a result, the current control means 13 limits the current to the third electric motor 12, and the third electric motor 12
Reduce the torque. Therefore, the torque of the direction changing roll 5 is reduced, and the slip between the steel material 3 and the direction changing roll 5 is prevented.

According to the second embodiment described above, in order to control the output side tension To and the output side tension Po, which change according to the states of the steel material 3 and the liquid 4a in the liquid tank 4, to the target values, the reference control current. ia can be given to the current control means 13,
As a result, the third electric motor 12 rotates the direction changing roll 5 at the target speed, so that stable traveling of the steel material 3 can be realized, and breakage of the steel material 3 on the outlet side of the liquid tank 4 can be prevented.

When a large torque is generated in the third electric motor 12 and the deviation between the input side tension Pi and the output side tension Po exceeds a predetermined value, a slip occurs between the steel material 3 and the direction changing roll 5. There is a risk that
When the deviation between the tension Pi on the input side and the tension Po on the output side becomes equal to or more than a predetermined value, the control current calculation means 19 of the reference control current i
Since the limiter 190 for limiting a to a predetermined range is provided, slippage between the steel material 3 and the direction changing roll 5 can be prevented, and the slippage does not damage the surface of the steel material 3.

Example 3. FIG. 7 is a schematic configuration diagram of a tension control system according to a third embodiment of the present invention. In FIG. 7, components corresponding to those shown in FIG. 4 are designated by the same reference numerals, and their description will be omitted. In FIG. 7, 20, 2
Reference numeral 1 denotes strains ε1 and ε of the pillar 14 that supports the direction changing roll 5.
2 is a strain detecting means, 22 is a strain detecting means 20,
Load calculation means for calculating a vertical load Pv and a horizontal load Ph of the column 14 based on the strains ε1 and ε2 detected in 21;
Reference numeral 23 denotes the direction changing roll 5 based on the vertical load Pv and the horizontal load Ph calculated by the load calculating means 22 and the liquid tank 4
Is a first estimating means for estimating the input-side tension Pi of the steel material 3 pulled in the input side direction and the output-side tension Po of the steel material 3 pulled in the output side direction of the liquid tank 4.

FIG. 8 is a view for explaining the tension of the steel material in the vicinity of the direction changing roll 5 in FIG. In FIG. 8, Pi is the tension on the input side, Po is the tension on the output side, Pv is the vertical load, Ph is the horizontal load, θ is the angle made by the steel material on the incoming side with respect to the perpendicular, and τ is the angle made by the steel material on the outgoing side with respect to the perpendicular. r represents the radius of the direction changing roll 5.

Next, the operation of the third embodiment will be described with reference to FIGS. 7 and 8. The description of the same parts as those of the first and second embodiments will be omitted. Column 1 which is an elastic body
Bending moment M applied to 4 and this bending morton M
There is a relation of the following formula 7 with the strain ε caused by.

[0045]

(Equation 7)

Here, E is the longitudinal elastic modulus of the column 14, I is the second moment of area of the column 14, and C is the distance from the neutral surface of the column 14 to the mounting position of the strain detecting means 20, 21. Two strains ε1 and ε2 that sandwich the center line of the pillar 14.
Considering the above, the strain due to the vertical load component of the column 14 is commonly included in both strains ε1 and ε2 with the same polarity, but the strain ε due to the bending moment M is included with the opposite polarity so as to cancel each other out by the strains ε1 and ε2. . Therefore, the strain ε (in this case, the strain ε1,
By detecting ε2) by the strain detecting means 20 and 21, the vertical load component of the column 14 and the bending moment M can be separately known. On the other hand, it is the input side tension Pi and the output side tension P that generate the bending moment M in the column 14.
The horizontal load Ph is a horizontal component of the resultant force with o, and the magnitude of the horizontal load Ph depends on the distance between the fixed end of the column 14 and the direction changing roll 5. Therefore, the strain ε
The vertical load Pv and the horizontal load Ph can be calculated by the load calculating means 22 from 1 and ε2. Also, the vertical load P
The following relationship is established between v, the horizontal load Ph, the input-side tension Pi, and the output-side tension Po.

[0047]

(Equation 8)

By transforming the above equation (8), the following equation (9) can be obtained, whereby the first estimating means 23 causes the input side tension P
i and the output side tension Po can be calculated.

[0049]

[Equation 9]

According to the third embodiment described above, the third electric motor 1 is used to estimate the input side tension Pi and the output side tension Po.
Since the vertical load Pv and the horizontal load Ph are calculated by using the strains ε1 and ε2 of the column 14 without using the current i flowing in 2, the input side tension Pi and the output side tension Po are estimated based on these. , Even if it is difficult to detect the current i of the third electric motor 12 with high accuracy, the output side tension To and the output side tension Po that change according to the state of the steel material 3 and the liquid 4a in the liquid tank 4 are targeted. In order to control the value, the reference control current ia can be applied to the current control means 13, whereby the third electric motor 12 rotates the direction changing roll 5 at the target speed, thus realizing stable running of the steel material 3. It is possible to prevent the steel material 3 from breaking on the exit side of the liquid tank 4.

When a large torque is generated in the third electric motor 12 and the deviation between the input side tension Pi and the output side tension Po exceeds a predetermined value, a slip occurs between the steel material 3 and the direction changing roll 5. However, there is a possibility that
When the deviation between the tension Pi on the input side and the tension Po on the output side becomes equal to or more than a predetermined value, the control current calculation means 19 of the reference control current i
Limiter 190 for limiting a within a predetermined range (see FIG. 6)
Since it is provided, the slip between the steel material 3 and the direction changing roll 5 can be prevented, and the surface of the steel material 3 is not scratched by the slip.

Example 4. FIG. 9 is a schematic configuration diagram of a tension control system according to Embodiment 4 of the present invention. 9, components corresponding to those shown in FIG. 4 are designated by the same reference numerals, and their description will be omitted. In FIG. 9, reference numeral 51 denotes a hollow-direction turning roll, the hollow of which is filled with a high-pressure fluid such as air. Reference numeral 24 is a load conversion unit that detects the pressure of the high-pressure fluid and calculates the vertical load Pv of the column 14 that supports the direction changing roll 51.

FIG. 10 is a diagram for explaining the tension of the steel material in the vicinity of the direction changing roll 51 in FIG. In FIG. 10, Pi is the tension on the input side, Po is the tension on the output side, Pv is the vertical load, θ is the angle made by the steel material on the input side with respect to the vertical line, τ is the angle made by the steel material on the output side with respect to the vertical line, and r is for direction change. The radius of the roll 51 is shown.

FIG. 11 is a schematic diagram of the direction changing roll 51 in FIG. In FIG. 11, 52 is a hollow part of the direction changing roll 51, 53 and 54 are hollow shafts of the hollow part 52 (corresponding to the central axis of the direction changing roll 51), and 55 is for feeding high-pressure air into the hollow part 52. Of the hollow shaft 53, 57 is a pressure sensor unit for detecting the air pressure of the hollow portion 52, 58 is an adjusting system tube connected to an air pressure adjusting system 60, and 59 Is a supply pipe for supplying high-pressure air to the air accumulation part 55, and 50 is a hermetic seal. When the hollow portion 52 of the direction changing roll 51 is filled with air, high-pressure air from a compressor (not shown) is supplied from the supply pipe 59 to be accumulated in the air accumulation portion 55, and the open / close valve 56 is opened. As a result, the air accumulation unit 55
The air is filled into the hollow portion 52 through the hollow shaft 53 and the pressure sensor portion 57 through the hollow shaft 54. Therefore, when the hollow portion 52 is deformed due to the pressure difference in the direction changing roll 51 and the air pressure inside the hollow portion 52 changes, the air pressure inside the pressure sensor portion 57 also changes, so the air pressure inside the hollow portion 52 is changed by the pressure sensor portion 57. It becomes possible to detect the change of. The pressure detected by the pressure sensor unit 57 is given to the load conversion means 24 (see FIG. 9), and the vertical load Pv of the column 14 is calculated. Then, the vertical load Pv is given to the first estimating means 16, and thereafter, the same operation as that of the second embodiment is performed.

By the way, even if harmful tension fluctuations having a relatively short cycle that occur at the time of starting / stopping the exit looper generally provided in the steel process line change the exit tension To of the liquid tank 4, the harmful tension fluctuations are caused. By designing the fluid pressure system of the direction changing roll 51 so as to absorb the tension fluctuations in the frequency band of 1, it is possible to prevent harmful tension fluctuations from reaching the inlet side of the liquid tank 4. For example, as shown in FIG. 12, by providing a pressure accumulator 62 in the middle of the pipe 61 connected to the hollow portion of the direction changing roll and providing a hole diameter narrowing portion 63 for narrowing the hole diameter in the pipe 61, , Absorb tension fluctuations in the frequency band of harmful tension fluctuations. Therefore, the pressure system of the fluid of the direction changing roll 51 can be designed by observing the pressure accumulator 62 and the hole diameter narrowed portion 63 as if they were capacitors and resistors in an electric circuit.

According to the fourth embodiment described above, the reference control current is used in order to control the output side tension To and the output side tension Po, which change according to the state of the steel material 3 and the liquid 4a in the liquid tank 4, to the target values. ia can be given to the current control means 13, whereby the third electric motor 12 can rotate the direction changing roll 5 at the target speed, thus realizing the stable running of the steel material 3, and the output of the liquid tank 4. The steel material 3 on the side can be prevented from breaking.

When a large torque is generated in the third electric motor 12 and the deviation between the input side tension Pi and the output side tension Po exceeds a predetermined value, a slip occurs between the steel material 3 and the direction changing roll 5. However, there is a possibility that
When the deviation between the tension Pi on the input side and the tension Po on the output side becomes equal to or more than a predetermined value, the control current calculation means 19 of the reference control current i
Since the limiter for limiting a within the predetermined range is provided, slippage between the steel material 3 and the direction changing roll 5 can be prevented, and the surface of the steel material 3 is not scratched by the slippage.

Further, a direction changing roll 51 having a hollow structure is used, and the hollow portion 52 is filled with a high pressure fluid such as air.
Since the pressure of this high-pressure fluid is detected and the vertical load Pv of the column 14 is calculated by the load conversion means 24, when the load detection device cannot be attached to the column 14 or the elastic body is long due to mechanical reasons. The above effect can be achieved even if the pillar cannot be used.

[0059]

As described above, according to the first aspect of the present invention, the vertical load detecting means for detecting the vertical load of the column supporting the direction changing roll, the detected vertical load and the current flowing through the third electric motor. And a first estimating means for estimating the input-side tension of the steel material pulling the direction-changing roll toward the inlet side of the liquid tank and the output-side tension of the steel material pulling toward the outlet side of the liquid tank based on Estimate the outlet tension, which is the tension of the steel material on the outlet side of the liquid tank, based on the input side tension, the output side tension, and the inlet side tension that is the tension of the steel material on the inlet side of the liquid tank detected by the tension detecting means. Control current calculation for determining a reference control current to the current control means based on the second estimating means, the estimated output side tension, output side tension, and preset target output side tension and target output side tension. Since it is configured by providing means, steel material and liquid tank In order to control the output side tension and the output side tension, which change according to the liquid state, to a target value, a reference control current is supplied to the current control means, whereby the third electric motor causes the direction changing roll to move at the target speed. It can be rotated, therefore stable running of steel material can be realized, and
The effect that the steel material can be prevented from breaking on the exit side of the liquid tank is obtained.

According to the second invention, the strain detecting means for detecting the strain of the column supporting the direction changing roll, and the load calculation for calculating the vertical load and the horizontal load of the column based on the detected strain. And the input side tension of the steel material pulling the direction change roll toward the inlet side of the liquid tank and the output side tension of the steel material pulling toward the outlet side of the liquid tank based on the vertical load and the horizontal load calculated above. First estimating means for
Based on the estimated input-side tension, output-side tension, and the inlet-side tension that is the tension of the steel material on the inlet side of the liquid tank detected by the tension detecting means, the outlet side that is the tension of the steel material on the outlet side of the liquid tank Second estimating means for estimating the tension, and the reference control current to the current control means is determined based on the estimated output side tension, output side tension, and preset target output side tension and target output side tension. Since the control current calculation means for controlling the output side tension and the output side tension that change according to the state of the steel and the liquid in the liquid tank are controlled to the target values, the reference control current is supplied to the current control means. Given this, the third electric motor can rotate the direction changing roll at the target speed, and therefore, the stable running of the steel material can be realized, and the steel material on the exit side of the liquid tank can be prevented from breaking. Is obtained. Further, since the current of the third electric motor is not used for estimating the input side tension and the output side tension, the above effect can be achieved even when it is difficult to detect the current with high accuracy.

According to the third invention, the direction-changing roll has a hollow structure, and the hollow is filled with a high-pressure fluid such as air. The column for supporting the direction-changing roll by detecting the pressure of the high-pressure fluid is used. Load conversion means for calculating the vertical load of
The input side tension of the steel material pulling the direction-changing roll toward the inlet side of the liquid tank and the output side tension of the steel material pulling toward the outlet side of the liquid tank based on the calculated vertical load and the current flowing through the third electric motor. Of the liquid tank on the basis of the first estimating means for estimating the above, and the estimated input side tension, output side tension, and the inlet side tension which is the tension of the steel material on the inlet side of the liquid vessel detected by the tension detecting means. Based on a second estimating means for estimating a delivery side tension which is a tension of the delivery side steel material, and the estimated delivery side tension, output side tension, preset target delivery side tension and target output side tension which are set in advance. Since the control current calculation means for determining the reference control current to the current control means is provided and configured, the output side tension and the output side tension that change according to the state of the steel material and the liquid in the liquid tank are controlled to the target values. Therefore, the reference control current is given to the current control means, As a result, the third electric motor can rotate the direction-changing roll at the target speed, so that stable running of the steel material can be realized, and the steel material can be prevented from breaking on the outlet side of the liquid tank. .
Further, since the pressure of the high-pressure fluid filled in the hollow of the direction-changing roll is detected to obtain the vertical load of the column supporting the direction-changing roll, if the load detecting device cannot be attached to the column, The above effect can be achieved even when a column having a long elastic body cannot be used for mechanical reasons.

According to the fourth aspect, when the deviation between the tension on the input side and the tension on the output side of the steel material exceeds a predetermined value, the control current calculating means is provided with a limiter for limiting the reference control current to be output within a predetermined range. Therefore, if the deviation between the tension on the input side and the tension on the output side exceeds a predetermined value, the torque of the direction-changing roll decreases, and therefore slippage between the steel material and the direction-changing roll can be prevented, and the slippage on the surface of the steel material can be prevented. The effect that it does not get scratched is obtained.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a tension control system according to a first embodiment of the present invention.

FIG. 2 is a diagram for explaining the tension and the like of the steel material near the direction changing roll in FIG.

FIG. 3 is a calculation block diagram of control current calculation means in FIG.

FIG. 4 is a schematic configuration diagram of a tension control system according to a second embodiment of the present invention.

5 is a diagram for explaining the tension of the steel material near the direction changing roll in FIG. 4 and the like.

6 is a calculation block diagram of control current calculation means in FIG. 4. FIG.

FIG. 7 is a schematic configuration diagram of a tension control system according to a third embodiment of the present invention.

FIG. 8 is a diagram for explaining the tension and the like of the steel material near the direction changing roll in FIG.

FIG. 9 is a schematic configuration diagram of a tension control system according to a fourth embodiment of the present invention.

FIG. 10 is a diagram for explaining the tension and the like of the steel material near the direction changing roll in FIG.

11 is a schematic configuration diagram of a direction changing roll in FIG.

FIG. 12 shows the direction changing roll 5 in the fourth embodiment.
It is a figure for demonstrating that the pressure system of 1 fluid is designed.

FIG. 13 is a schematic configuration diagram of a conventional tension control system.

FIG. 14 is a diagram for explaining the tension and the like of the steel material near the direction changing roll in FIG.

[Explanation of symbols]

1 tension generating bridle roll, 2 reference speed bridle roll, 3 steel material, 4 liquid tank, 4a liquid,
5,51 Direction changing roll, 6,10,12 electric motor, 7,13 current control means, 8 tension detection means, 9
Tension control current output means, 14 columns, 15 vertical load detection means, 16, 23 1st estimation means, 17 2nd
Estimation means, 18, 19 Control current calculation means, 20, 2
1 strain detection means, 22 load calculation means, 24 load conversion means, Pi input side tension, Po output side tension, Pv vertical load, Li, Lo liquid running distance, Ti input side tension,
To output side tension, Po 'Target output side tension, To'
Target outlet tension, ia reference control current, i current, r radius of roll for direction change, angle made by steel with respect to θ, τ perpendicular, ε1, ε2 column distortion, Ph horizontal load, 50 hermetic seal, 52 hollow part, 53, 54 hollow shaft, 55
Air accumulation part, 56 Open / close valve, 57 Pressure sensor part, 58
Adjustment system pipe, 59 supply pipe, 60 air pressure adjustment system, 6
1 tube, 62 pressure accumulator, 63 hole diameter reduction part, 18
1, 182, 188 subtraction circuit, 183 weighting circuit, 184 addition circuit, 185 multiplication circuit, 186
Division circuit, 187 PID compensation circuit, 189 magnitude determination circuit, 190 limiter.

Claims (4)

[Claims] 1. A tension generating bridle roll for generating tension in a steel material traveling in a steel process line, a reference speed bridle roll for causing the steel material to travel at a reference speed, and the tension generating bridle roll. A liquid tank for cooling the traveling steel material between the bridle roll for the reference speed, a direction changing roll for changing the traveling direction of the steel material in the liquid tank, and the tension generating bridle roll. A first electric motor for driving, a second electric motor for driving the bridle roll for reference speed, and a third electric motor for driving the direction changing roll.
And a current control means for controlling the current to the third electric motor according to the reference control current, and by controlling the first, second and third electric motors respectively, the tension of the traveling steel material is kept constant. In a tension control system in a steel process line configured to control the vertical load, a vertical load detecting unit that detects a vertical load of a column that supports the direction changing roll, the detected vertical load, and the third load. The first side for estimating the input side tension of the steel material pulling the direction changing roll in the inlet side direction of the liquid tank and the output side tension of the steel material pulling in the outlet side direction of the liquid tank based on the current flowing in the electric motor of The outlet side of the liquid tank based on the estimating means, the estimated input side tension, the output side tension, and the inlet side tension which is the tension of the steel material on the inlet side of the liquid vessel detected by the tension detecting means. Second estimating means for estimating the output side tension which is the tension of the steel material, and the current control based on the estimated output side tension, output side tension, and preset target output side tension and target output side tension. And a control current calculating means for determining a reference control current to the means. 2. A tension generating bridle roll for generating tension in a steel material traveling in a steel process line, a reference speed bridle roll for causing the steel material to travel at a reference speed, and the tension generating bridle roll. A liquid tank for cooling the traveling steel material between the bridle roll for the reference speed, a direction changing roll for changing the traveling direction of the steel material in the liquid tank, and the tension generating bridle roll. A first electric motor for driving, a second electric motor for driving the bridle roll for reference speed, and a third electric motor for driving the direction changing roll.
And a current control means for controlling the current to the third electric motor according to the reference control current, and by controlling the first, second and third electric motors respectively, the tension of the traveling steel material is kept constant. In a tension control system in a steel process line configured to control so as to keep the vertical direction of the column based on the strain detection means and strain detection means for detecting the strain of the column supporting the turning roll. A load calculating means for calculating a load and a horizontal load, and an input side tension of the steel material for pulling the direction changing roll in the inlet side direction of the liquid tank based on the calculated vertical load and horizontal load and the liquid tank First estimating means for estimating the output side tension of the steel material pulled in the outlet side of the liquid tank, and the inlet side of the liquid tank detected by the estimated input side tension, output side tension and tension detecting means Second estimating means for estimating the outlet tension which is the tension of the steel on the outlet side of the liquid tank based on the inlet tension which is the tension of the steel, and the estimated outlet tension and the output tension in advance A tension control system in a steel process line, comprising: a control current calculation means for determining a reference control current to the current control means based on the set target output side tension and target output side tension. 3. A tension-generating bridle roll for generating tension in a steel material traveling in a steel process line, a reference-speed bridle roll for causing the steel material to travel at a reference speed, and the tension-generating bridle roll. A liquid tank for cooling the traveling steel material between the bridle roll for the reference speed, a direction changing roll for changing the traveling direction of the steel material in the liquid tank, and the tension generating bridle roll. A first electric motor for driving, a second electric motor for driving the bridle roll for reference speed, and a third electric motor for driving the direction changing roll.
And a current control means for controlling the current to the third electric motor according to the reference control current, and by controlling the first, second and third electric motors respectively, the tension of the traveling steel material is kept constant. In a tension control system in a steel process line configured to control so as to keep the pressure-reducing roll in a hollow structure, the hollow is filled with a high-pressure fluid such as air, and the pressure of the high-pressure fluid is changed. The load conversion means for detecting and calculating the vertical load of the column supporting the direction changing roll, and the direction changing roll for the liquid tank based on the calculated vertical load and the current flowing through the third electric motor. Estimating means for estimating the input side tension of the steel material pulled in the inlet side direction of the liquid tank and the output side tension of the steel material pulled in the outlet side direction of the liquid tank, and the estimated input side tension Secondly estimating the output side tension, which is the tension of the steel material on the outlet side of the liquid tank, based on the output side tension and the inlet side tension, which is the tension of the steel material on the inlet side of the liquid tank detected by the tension detecting means. And a control current calculation means for determining a reference control current to the current control means based on the estimated output side tension, output side tension, and preset target output side tension and target output side tension. And a tension control system in a steel process line. 4. The control current calculating means is provided with a limiter for limiting the reference control current to be output within a predetermined range when the deviation between the input side tension and the output side tension exceeds a predetermined value. The tension control system in a steel process line according to claim 1, 2 or 3.