JPH0596315A - Controller for continuous rolling mill - Google Patents

Abstract

PURPOSE:To provide a controller for a continuous rolling mill which can keep the top and rear ends of rolling stock under accurater control. CONSTITUTION:A deviation in passing timing when the rolling stock passes each rolling stand based on the switching timing of speed reference and the detecting output of biting of the stock is required by a 1st arithmetic means 14 and an amount of correction of speed reference and an amount of correction of rolling reduction are required by a 2nd arithmetic means 13. The rolling down reference is corrected by the amount of correction of rolling reduction, a corrected rolling reduction reference of each rolling stand is calculated by a 3rd arithmetic means and a rolling reduction of each rolling stand is controlled by a 1st controlling means 10 based on this corrected rolling reduction reference. The speed reference is corrected by the amount of correction of speed reference, the corrected speed reference of a rolling roll at each rolling stand is calculated by a 4th arithmetic means 7 and the rotating speed of the rolling roll at each rolling stand is controlled by a 2nd controlling means 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a controller for more accurately controlling the leading end and the trailing end of a material in a continuous rolling mill that continuously rolls by a plurality of rolling stands arranged in tandem. Is.

[0002]

2. Description of the Related Art A conventional controller for a continuous rolling mill will be described by taking a continuous rolling mill for rolling a pipe as an example.

In a continuous rolling mill, for example, a pipe rolling mill for continuously rolling a pipe, it is common for the leading end and the rear end of the pipe to bulge with respect to the center during the rolling process. Therefore, in the conventional control device,
In order to remove this bulge and obtain a product with a constant pipe diameter, tip control and rear end control are performed.

FIG. 4 shows a schematic configuration of a conventional control device used for rolling a pipe material. In addition, in the following description, a continuous rolling mill including three stands will be described as an example. In FIG. 4, each of the stands # 1, # 2, and # 3 carries out continuous rolling of the rolled material 2 by the rolling roll 1 to which a rolling force is applied from the rolling roll rolling drive device 5. The rolling roll 1 is driven by a drive motor 3 to roll and convey the rolling material 2. The transport speed in this case is controlled by the speed controller 6 via the drive motor 3. The speed reference for the speed control device 6 of each of the stands # 1, # 2, # 3 is the speed according to each speed reference set by the speed reference setting means 8 and the switching timing set by the speed reference switching timing setting means 9. It is calculated by the reference calculation means 7, and the calculated speed reference is given to the speed control device 6. On the other hand, the speed control device 6
In contrast, the rotational speed of the rolling roll drive motor 3 detected by a speed detector (not shown) is negatively fed back.
As a result, the speed control device 6 controls the speed of the drive motor 3 for driving the rolling roll 1 so as to match the speed reference given by the speed reference calculation means 7. Thereby, the rolled material 2 is rolled at a predetermined rolling speed. On the other hand, the reduction amount control device 10 controls the reduction amount of the rolling roll 1 of each stand via the rolling roll reduction drive device 5 for each of the stands # 1, # 2, and # 3. In this case, the value calculated by the rolling-down reference calculating means 11 based on the set value of the rolling-down reference setting means 12 is given as the rolling-down reference for each stand. As a result, the reduction control device 10 drives the rolling roll reduction drive device 5 in accordance with the reduction reference calculated by the reduction reference calculation means 11 to set the rolling gap of the rolling roll 1. In addition, the passage timing of the leading end and the trailing end of the rolled material 2 is detected on the upstream side of the uppermost stream stand # 1 by the rolled material detector 15, and the detection signal is sent to the speed reference switching timing setting means 9.

The operation of the control device configured as described above will be described with reference to the time chart of FIG. 5 and the rolling state explanatory diagrams of FIGS. 6 and 7. In addition, in FIG.
The horizontal axis represents time t, and the vertical axis represents the set rotation speed v of each rolling roll. In FIG. 6, stands # 1, # 2, #
In addition to 3, a fourth stand # 4 is also shown.

In FIG. 5, TREF1, TREF2,
TREF3 is a set rotational speed of the rolling roll 1 of the stands # 1, # 2, # 3 before the rolling start time t ₁ and is given from the speed reference calculation means 7 to each speed control device 6. The set rotation speed for each rolling roll 1 is TREF1 <T
There is a relation of REF2 <TREF3, and the downstream stands # 2 and # 3 are driven at a higher speed than the adjacent upstream stands # 1 and # 2.

Now, after the rolling start time t ₁ , as shown in FIG. 6A, the # 1 stand is accelerated to the rotational speed TREF2 with the tip of the rolled material 2 being caught in the # 2 stand. At this time, tension is applied to the tip of the rolled material 2 due to the difference in roll peripheral speed between the # 1 and # 2 stands. Similarly,
At time t ₂ , both the # 1 and # 2 stands are accelerated to the rotation speed TREF3 with the tip of the material being meshed with the # 3 stand as shown in FIG. 6B.
Tension is applied to the rolled material 2 due to the difference in roll peripheral speed between the # 2 and # 3 stands.

As described above, in the conventional rolling mill control apparatus, the upstream stand is sequentially accelerated every time the downstream stand bites the tip of the rolled material 2 to remove the bulge at the tip of the rolled material 2. I am trying. The timing at which the downstream stand is engaged with the rolled material 2 is determined by the rolled material detector 15.
It is set by the speed switching timing setting means 9 before the start of rolling on the basis of the passage timing of. # 1, # 2, #
The acceleration rate of each speed reference of the three stands is common to each stand, and the speed reference value during acceleration due to this is calculated by the speed reference calculation means 7. The acceleration rate based on this speed is #
1, # 2, # 3 are given to the speed control device 6 of each stand, and as a result, tip control is performed based on the speed pattern shown in the time chart of FIG.

When the predetermined leading edge control is completed, the central portion of the rolled material 2 is rolled at a steady rolling speed, and then the trailing edge control is performed. As shown in FIG. 7A, when the rolling material detector 15 detects the passage of the rear end of the rolling material 2 at time t ₆ (FIG. 5), the roll speed of the # 1 stand is set to BR.
Decelerate to EF1. As a result, tension is applied to the rear end of the rolled material 2 due to the difference in roll peripheral speed between the # 1 and # 2 stands. Next, as shown in FIG. 7B, after the time t _{7 when} the trailing end of the rolled material 2 leaves the # 1 stand, the # 2 stand is decelerated to the rotation speed BREF2, and the roll circumference between the # 2 and # 3 stands is reduced. Tension is applied to the rear end of the rolled material 2 due to the speed difference.

As described above, in the conventional control device, each time the trailing edge of the rolled material 2 passes through the adjacent upstream stand, the roll speed of the stand is reduced to reduce the rolled material 2.
The bulge at the rear end is removed. The timing at which the rolled material 2 passes through each stand is given by the speed reference switching timing setting means 9 based on the passage timing of the rolled material 2 which is the output signal of the rolled material detector 15, as in the case of the tip control. As a result, the trailing edge control is performed according to the speed pattern shown in the time chart of FIG.
In addition, when the rolled material 2 completely exits from its own stand, each of the # 1, # 2, and # 3 stands sets the reference of the respective rotation speeds to TRE for the next material rolling sequentially from time t _{9 to} t _11.
Change the setting to F1 to TREF3.

[0011]

In the above-mentioned conventional control apparatus, the speed reference switching timing is set by the speed reference switching timing setting means 9 based on the output of the rolling material detector 15, which is used for rolling. The operator sets the material 2 based on conditions such as the rolling speed of the material 2. However, it is necessary to set the material according to the rolling schedule without any mistakes. Further, the rolling roll 1 of each of the # 1, # 2, and # 3 stands. Between rolling material 2 and rolling roll 1
Due to a change in the roll diameter of No. 1 and the like, a deviation occurs between the machine specification setting value and the rolling result of actual rolling, and there is a limit to performing accurate leading edge control or trailing edge control.

The present invention has been made in consideration of the above problems, and an object of the present invention is to provide a control device for a continuous rolling mill capable of more accurately controlling the leading end and the trailing end of a rolled material. And

[0013]

A control device for a continuous rolling mill according to the present invention sets a detecting means for detecting the biting timing of a rolled material into each rolling stand and a speed reference of a rolling roll of each rolling stand. First setting means, second setting means for setting the speed reference switching timing of each rolling stand, third setting means for setting the rolling reference of the rolling roll of each rolling stand, and for each rolling stand, First calculating means for calculating a difference between the speed reference switching timing set by the speed reference switching timing setting means and the biting timing detected by the detecting means as a deviation of the passage timing at which the rolled material passes through the rolling stand. And second calculation means for calculating the speed reference correction amount and the reduction amount correction amount of each rolling stand based on the deviation of the passage timing, Third for calculating the modified pressure criteria for each rolling stand is corrected by reduction the correction amount under the reference
And first control means for controlling the amount of reduction of the rolling rolls of each rolling stand based on the corrected rolling reduction standard, and the correction of the rolling roll of each rolling stand by correcting the speed reference with the speed reference correction amount. It is characterized by comprising: a fourth calculating means for calculating the speed reference thus adjusted; and a second control means for controlling the rotation speed of the rolling roll of each rolling stand based on the corrected speed reference.

[0014]

According to the control device for a continuous rolling mill of the present invention configured as described above, the deviation of the passage timing when the rolled material passes each rolling stand based on the speed reference switching timing and the material jam detection output. Is calculated by the first calculation means. Based on the deviation of the passage timing, the speed reference correction amount and the reduction amount correction amount of each rolling stand are obtained by the second calculation means. Then, the rolling-down reference is corrected by the rolling-down amount correction amount, and the corrected rolling-down reference of each rolling stand is calculated by the third calculating means, and the rolling-down amount of each rolling stand is first adjusted based on the corrected rolling-down reference.
Is controlled by the control means. Further, the speed reference is corrected by the speed reference correction amount, and the corrected speed reference of the rolling roll of each rolling stand is calculated by the fourth calculating means. Further, the rotation speed of the rolling roll of each rolling stand is controlled by the second control means based on the corrected speed reference. Thus, according to the control device of the present invention, the speed reference and the reduction amount are corrected by using the deviation of the rolling material passage timing of each rolling stand obtained based on the speed reference switching timing and the material trapping detection output, and the accuracy is corrected. The front end control and the rear end control can be performed.

[0015]

FIG. 1 shows an embodiment of a control device for a continuous rolling mill according to the present invention. The control device of this embodiment corresponds to the conventional control device shown in FIG. 4 with the addition of a material trapping detection means 4, a correction amount calculation means 13, and a material passage timing deviation calculation means 14. The material catching detecting means 4 is provided for each stand and detects the timing when the rolled material 2 is caught in the corresponding stand. This bite detection is performed, for example, by monitoring the rotation speed of the electric motor 3 that drives the rolling rolls of each stand and detecting a sudden decrease in speed.

The material passage timing deviation calculating means 14 is
The elapsed time t _vi from when the tip of the rolled material 2 is bitten by the #i (i ≧ 1) stand to when the tip of the rolled material 2 is bited by the next # i + 1 stand is calculated by the rolling material bite detection means 4. Difference based on the set time (switching timing) t _si from the switching of the speed reference of the #i stand to the switching of the speed reference of the # i + 1 stand, which is calculated based on the detection output and is set by the speed reference switching timing setting means 9. Deviation Δt of the passage timing at # i + 1 corresponding to
_i is obtained as Δt _i = t _si −t _vi (1) (see FIG. 3B), and this is sent to the correction amount calculation means 13. The deviation Δt _o of the passage timing at the # 1 stand is set by the speed reference switching timing setting means 9, and the passage setting time of the rolling material 2 from the installation location of the rolling material detector 15 to the # 1 stand (pass timing). ) T _so and the elapsed time t _vo from when the leading edge of the rolled material is detected by the rolled material detector 15 to when the rolled material 2 is caught in the # 1 stand,
It is obtained by the material passage timing deviation calculation means 14 (see FIG. 3A).

The correction amount calculation means 13 includes a passage timing deviation Δt _i obtained as a calculation result of the material passage timing deviation calculation means 14, a material passage timing correction set value a _i , a speed correction set value b _i , and a reduction amount correction. Based on the value c _i , the speed reference correction amount ΔV _{i + 1 at} each stand
And the reduction correction amount ΔSD _{i + 1} are calculated by the equations (2) and (3), respectively.

ΔV _{i + 1} = Δt _i · a _i + Δt _i · b _i (2) Pass timing deviation Δt _i obtained by the equation (1)
The rolled material is given to the speed reference calculation means 7 as the speed reference correction amount of the next stand (i + 1 stand) corresponding to each of the stands, and is corrected sequentially. Further, the reduction correction amount ΔSD _{i + 1} of the stand is calculated with respect to the speed reference correction amount ΔV _{i + 1} obtained by the equation (2).

ΔSD _{i + 1} = (Δt _i · a _i + Δt _i · b _i ) + Δt _i · c _i (3) With respect to the reduction correction amount obtained in (3), if necessary, a dead band or the like for control. Is added to control the reduction control device 10 in consideration of control stability such as giving a correction amount to the reduction reference correction means 11 when a certain range is exceeded.

FIG. 2 shows an example of a specific configuration of the correction amount calculation means 13. The correction amount calculation means 13 shown in FIG. 2 includes a passage time correction setting device 31, a speed correction setting device 32, a reduction amount correction setting device 33, multipliers 34, 35 and 36, and adders 37 and 38.

The product a of the passage timing deviation Δt _i obtained by the material passage timing deviation calculating means 14 and the set value a _i set by the passage time correction setter 31.
_i · Δt _i is calculated by the multiplier 34. The product b _i · Δt _{i of} the set value b _i set by the speed correction setting device 32 and the passage timing deviation Δt _i is calculated by the multiplier 35. Similarly, the product c _i · Δt _{i of} the set value c _i set by the reduction amount setting device 33 and the passage timing deviation Δt _i is calculated by the multiplier 36. The rolling speed correction amount ΔV _{i + 1} is obtained as the sum of the products obtained by the multipliers 34 and 35. Also, for this sum,
Further, the reduction amount correction amount ΔSD _{i + 1} is obtained by adding the product c _i · Δt _i obtained by the multiplier 36.

Based on the reduction amount correction amount ΔSD _{i + 1} obtained by the correction amount calculating means 13 in this manner, the reduction reference set by the reduction reference setting means 12 is corrected, and the corrected reduction reference is reduced. It is calculated by the reference calculation means 11. Based on the corrected rolling reduction standard, the rolling reduction device 10 controls the roll gap of the rolling roll 1 of each stand through the rolling roll rolling drive device 5. When Δt _i (i ≧ 0)> 0, the roll gap of the # i + 1 stand is controlled to open, and when Δt _i <0, the roll gap of # i + 1 stand is controlled to close. ..

On the other hand, the speed reference set by the speed reference setting means 8, the speed reference switching timing t _{si + 1 of} the # i + 1 stand set by the speed reference switching timing setting means 9, and the correction amount calculation means 13 Based on the speed correction amount ΔV _{i + 1} obtained by the above, the corrected speed reference and speed reference switching timing of the # i + 1 stand are calculated by the speed reference calculation means 7, and the corrected speed reference is further calculated. The speed control device 6 controls the motor 3 via the electric motor 3 so that the rotation speed of the rolling roll 1 matches the corrected speed reference based on the switching timing and the speed reference.

As described above, each time the front end of the rolled material 2 reaches each rolling stand, the passage time deviation Δt _i of the rolled material 2 is obtained, and the speed reference and the rolling control are performed based on the passage time deviation Δt _i. By repeating the correction of the amount, rational tip control of the rolled material 2 can be performed. Although the leading end control of the rolled material is described in this embodiment, the trailing end control can be performed in the same manner as described above.

In the above embodiment, the rolling reduction standard of the stand is corrected. However, in addition to this correction, the velocity reference and the rolling reduction control amount of the downstream stand can be corrected at any time. Therefore, more accurate rolling can be performed.

Further, in the above-mentioned embodiment, the case of rolling the pipe material is exemplified, but the present invention can be applied to other continuous rolling equipments and the same effect can be obtained.

[0027]

According to the present invention, the speed reference and the reduction amount of each rolling stand are corrected based on the deviation between the actual stand passing timing of the leading or trailing end of the rolled material and the set timing, and the rolling material slips. It is possible to eliminate instability factors in rolling such as a deviation from the setting data due to and the influence of machine specifications, and to perform stable continuous rolling control.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of a control device for a continuous rolling mill according to the present invention.

FIG. 2 is a block diagram showing a specific example of a correction amount calculation means in FIG.

FIG. 3 is a rolling state explanatory view for explaining the operation of the present invention.

FIG. 4 is a block diagram showing a configuration of a conventional control device.

FIG. 5 is a time chart showing speed patterns of leading edge control and trailing edge control applied to a continuous rolling mill.

FIG. 6 is a rolling state explanatory view for explaining tip control by a conventional control device.

FIG. 7 is a rolling state explanatory view for explaining trailing end control by a conventional control device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rolling roll 2 Rolling material 3 Rolling roll drive motor 4 Material entrapment detection means 5 Rolling roll reduction drive device 6 Speed control device 7 Speed reference calculation means 8 Speed reference setting means 9 Speed reference switching timing setting means 10 Reduction control device 11 Reduction Reference calculation means 12 Reduction reference setting means 13 Correction amount calculation means 14 Material passage timing deviation calculation means 15 Rolling material detector

Claims (1)

[Claims] 1. A controller for a continuous rolling mill that performs continuous rolling by a plurality of rolling stands arranged in tandem, the detecting means detecting a biting timing of rolled material into each rolling stand, and each rolling stand. Setting means for setting the speed reference of each rolling stand, second setting means for setting the speed reference switching timing of each rolling stand, and third setting for setting the rolling reference of the rolling roll of each rolling stand. Means and the difference between the speed reference switching timing set by the speed reference switching timing setting means for each rolling stand and the biting timing detected by the detecting means, the rolled material passes through the rolling stand. First computing means for computing as timing deviation, and speed reference correction amount for each rolling stand based on the deviation of the passage timing Second for calculating the reduction correction amount and
And a third calculating means for calculating the corrected rolling-down standard of each rolling stand by correcting the rolling-down standard by the rolling-down amount correction amount, and the rolling roll of each rolling stand based on the corrected rolling-down standard. And a fourth control means for controlling the reduction amount of the rolling roll, and a fourth calculation means for correcting the speed reference by the speed reference correction amount to calculate the corrected speed reference of the rolling roll of each rolling stand. A control device for a continuous rolling mill, comprising: a second control unit that controls a rotation speed of a rolling roll of each rolling stand based on a speed reference.