JPH04182019A - Device for controlling sheet thickness on rolling mill - Google Patents

Abstract

PURPOSE:To manufacture the products with good accuracy in sheet thickness by providing the tension adjusting device capable of adjusting the tension of the rolled stock. CONSTITUTION:The variation of tension which is generated at a result of changing the roll gap of the rolling mill for controlling sheet thickness is adjusted with the press roll 38 by elongating or contracting the hydraulic cylinder 46 so as to make the tension constant by adjusting the position of the press roll of the moving side. The low-pass filter 49 removes the composition over the contact frequency from the variation detecting signal of roll, and obtains the signal of the deviation of roll position. And the high-pass filter 60 removes the composition under the contact frequency from the tension detecting signal of the rolled stock 1, obtains the variation signal, and the roll movement instruction is obtained from the tension control gain.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a rolling mill that employs a hydraulic rolling method.
This invention relates to a plate thickness control device for a rolling mill that achieves highly responsive plate thickness control.

[Prior Art] Fig. 6 shows an example of a jingle stand reversible cold rolling mill with reels arranged on the entry and exit sides as a conventional rolling mill employing a hydraulic rolling method. In this figure, a rolled material 1 is sent out from an unwinding reel 2, passes from a deflector roll 3 to between work rolls 4 and 5, is subjected to a predetermined rolling process, and then passes through a deflector roll 6 and is wound up. It is wound up on the reel 7 for use. The unwinding reel 2 and the take-up reel 7 are driven by motors 8 and 9, respectively, and a rolling motor tension control device 11. 12 are provided. The tension control device t11-12 generally controls the motor current to be proportional to the tension. Further, the rolling speed of the line is controlled to a predetermined value by controlling the speed of the work roll drive motor 13 of the rolling mill 10 by a speed control device 14.

In FIG. 6, 15 is a load cell for detecting rolling load, 16 is an upper back-up roll, and 17 is a lower back-up roll. 18 is a hydraulic cylinder that sets the roll gap between work rolls 4.5, 19 is a hydraulic cylinder 1
8 and the servo valve 20, and 21 is a displacement meter that detects the displacement of the reduction ram 22 installed in the hydraulic cylinder 18. 23 is a servo amplifier that sends an opening command (current signal) to the servo valve 20; 24 is a coefficient unit that gives a control gain of 6 to amplify the output signal of the adder/subtractor 25, and controls the reduction position S' of the reduction ram 22; .

The basic position control loop compares and calculates the command signal R and the output signal S of the displacement meter 21, and applies the coefficient multiplier to the deviation signal e.
4 by the gain Kc, and this signal controls the opening degree of the servo valve 20 via the servo amplifier 23, and the piping 19
The position S' of the reduction ram 22 is controlled by adjusting the amount of pressure oil supplied from the hydraulic cylinder 18 to the hydraulic cylinder 18. As a result, the lower back-up roll 17 and the lower work roll 5 move up and down, and the opening degree (roll gap) between the upper and lower work rolls 4.5 is adjusted to a predetermined value. This is carried out by the hydraulic pressure lowering device 26.
That's what it means.

Furthermore, simply controlling the position S' of the reduction ram 22 causes an error in the roll gap between the upper and lower work rolls 4.5 corresponding to the elongation of the rolling mill 10 under rolling load. Therefore, the standard rolling load P is usually set at a certain timing after the start of rolling.
ref is stored, and the difference ΔP between the signal P representing the rolling load during rolling detected by the load cell 15 is obtained by the adder/subtractor 27, and the difference ΔP is calculated by the coefficient unit 28 as the mill constant Km (rolling machine 1
(This corresponds to a spring constant of 0 and is determined in advance) to find the elongation of the mill, and then further multiplies it by the correction gain C that determines the percentage to be corrected to obtain the position Is of the reduction ram 22.
A correction signal CP for correcting ' is obtained, and this signal is applied to an adder 29 in order to be used as a command to the basic position control loop in the hydraulic lowering device 26, so that the position S' of the lowering ram 22 is corrected. Generally, this is called mill constant control device 3.
Say 0.

Furthermore, the absolute thickness of the rolled material l on the exit side of the rolling mill 10 is set to a target value h.
In order to match the target value href, an adder/subtractor 33 compares the signal detected by the thickness gauge 31 provided at the exit side of the rolling mill 10 (thickness gauge 32 is used when running in the reverse direction) and the target value href. to find the deviation Δh, pass it through the integral controller 34, and then use the coefficient unit 35 to correct the position S' of the reduction ram 22 by multiplying it by a correction gain 1 + (M/Ke) to correct it to the actual reduction position. A correction signal ch is obtained, which is also applied to the adder 29 in order to be used as a command to the basic position control loop in the hydraulic pressure reduction device 26, so that the position S' of the reduction ram 22 is corrected. This is called a monitor AGC device 36.

Here, M is a constant representing the hardness of the rolled material 1 and is determined in advance. Ke is a controlled Mill constant, and Ke=Km/ (1
-c) relationship.

[Problems to be Solved by the Invention] In order to control the thickness of the rolled material 1 in the rolling mill 10 shown in FIG. The tension on the input and output sides also changes. For example, if the roll gap between the work rolls 4 and 5 is narrowed in order to reduce the plate thickness, the rolled material l
expands, and the tension on the entry and exit sides decreases. Changes in tension can be absorbed by changing the circumferential speeds of the unwinding reel 2 and the take-up reel 7, which have large inertia on the input and unloading sides, but the response is generally an order of magnitude slower than that of the hydraulic pressure reduction device 26. Even if the roll gap is changed and the tension is changed, the tension cannot be returned to the set value as quickly as the hydraulic lowering device 26. Therefore, the tension on the entry and exit sides decreases, and as a result, the apparent top-rolled material l
The effect is as if the deformation resistance has increased, and the roll gap does not become narrower. In other words, the plate thickness does not become thinner. In other words, even if an attempt is made to reduce the thickness of the plate using the high-speed hydraulic reduction device 26, the thickness cannot be reduced faster than the response of the circumferential speed change of the reels 2 and 7 of the motors 8 and 9 on the input and output sides.

Therefore, even if the mill constant control device 30 attempts to remove this by performing mill constant control, the plate thickness control will not respond to a fast entrance plate thickness disturbance of 2 to 3 Hz or more for the reasons mentioned above. Could not be removed.

Using the hydraulic reduction device 26, the reduction ram 22 can be moved as quickly as possible.
It is often heard at the rolling site that even if the position S' is controlled, the accuracy of plate thickness control is not as good as expected, and this is because of the above-mentioned reasons.

FIG. 7 is an example of a simulation performed by the present inventor using a computer, which clarifies the above. The object of the simulation was the jingle stand reversible cold rolling mill shown in Figure 6, with the tension set at the entry side being 1.36.
)n, exit side set tension 2.35 )n, entrance side plate thickness 0.52
mm, plate width 1800mm material at rolling speed 1800m
This is an example in which the roll gap was reduced by 10 μm in steps under the condition that the target plate thickness was 0.3 mm at a speed of 0.3 mm. The response of the hydraulic lowering device 26 is assumed to have a 90 degree phase delay of 20 Hz in the frequency response, and a step response of (1
It is a high-speed device that reaches the target value in less than 0.4 seconds.

Looking at the simulation results, the roll gap was set to 10.
When changing μm, the exit side plate thickness change Δh reaches a steady value in approximately 1 second. Although the actual hydraulic pressure reduction reaches the target value in 0.04 seconds, the reason why the plate thickness changes only 25 times slower is because the circumference of reels 2 and 7 on the input and output side This is because the response to speed changes is slow. In other words, the tension on the reel 2.7 is generally controlled by keeping the motor current constant, or the inertia of the reels 2 and 7 including the motors 8 and 9 is quite large, and the circumferential speed of the reel 2.7 is controlled by keeping the tension fluctuations constant. This is because it takes about 1 second to reach the next steady-state value.

The present invention has been made in view of the above-mentioned points, and by quickly suppressing tension fluctuations on the entry and exit sides of the rolling mill that occur as a result of changing the roll gap of the rolling mill in order to control the board thickness, It is an object of the present invention to provide a plate thickness control device for a rolling mill that can improve the responsiveness of thickness control and obtain a highly accurate product plate thickness.

[Means for Solving the Problem] The invention according to claim 1 is a rolling mill equipped with a hydraulic rolling device that sets a roll gap between upper and lower work rolls. A tension adjustment device that can adjust the tension of the rolled material using a presser roll is provided, and a displacement meter that detects the amount of displacement of the presser roll, and a roll displacement signal detected by the displacement meter and a roll position setting device are provided. A roll steady state controller comprising an adder/subtractor for obtaining a roll position deviation signal by taking the deviation of a roll position setting signal, and a coefficient unit for multiplying the roll position deviation signal from the adder/subtractor by a position control gain to obtain a roll steady position control command. A tension control system that includes a position control device, a tension meter that detects the tension applied to the rolled material, and a coefficient unit that multiplies the tension detection signal detected by the tension meter by a tension control gain to obtain a roll movement command. an adder for adding the roll steady position control command and roll movement command from each of the coefficient units to obtain a roll position control command; This invention relates to a plate thickness control device for a rolling mill, characterized in that a hydraulic cylinder control device is provided with a servo amplifier that sends an opening adjustment command to a servo valve that supplies and discharges an operating body.

The invention of claim 2 includes a low-pass filter that removes components higher than the corner frequency from the roll displacement signal detected by the displacement meter to obtain a roll steady displacement signal to be sent to the adder/subtractor; and The present invention relates to a plate thickness control device for a rolling mill, which is equipped with a high-pass filter that removes components below the point frequency and obtains a tension fluctuation signal to be sent to the coefficient unit of the tension control device.

The invention according to claim 3 relates to a plate thickness control device for a rolling mill in which the corner frequency of at least the high-pass filter of the high-pass filter and the low-pass filter can be changed.

The invention of claim 4 provides a rolling mill equipped with a corner frequency calculator for determining a corner frequency change signal to be sent to at least one of a high-pass filter and a low-pass filter, based on the rolling speed from a rolling speed setting device. This is related to a plate thickness control device.

The invention according to claim 5 provides a rolling mill plate provided with a corner frequency calculator for calculating a corner frequency change signal to be sent to at least one of a high-pass filter and a low-pass filter, based on a rolling speed detected value from a speedometer. This is related to the thickness control device.

[For production] The invention of claim 1 operates as follows.

First, in the roll steady position control device, when a roll position setting signal is set in the roll position setter, the adder/subtractor sends the roll position setting signal as it is as a roll position deviation signal to the coefficient unit, and the coefficient unit calculates the roll position from the adder/subtractor. Multiply the deviation signal by the position control gain to obtain the roll steady position control command.

Then, the adder of the hydraulic cylinder control device sends the roll steady position control command from the coefficient unit of the roll steady position control device as it is to the servo amplifier as a roll position control command.
The servo amplifier sends an opening adjustment command to the servo valve of the hydraulic cylinder based on the roll position control command from the adder.

As a result, the servo valve supplies and discharges the operating body to the hydraulic cylinder of the tension adjustment device in accordance with the opening adjustment command, and the hydraulic cylinder expands and contracts to hold the presser roll so that its position matches the roll position setting signal. Move the roll.

Then, the displacement meter detects the displacement amount of the presser roll and sends a roll displacement signal to the adder/subtractor, and the adder/subtractor calculates the deviation between the roll displacement signal and the roll position setting signal set in the roll position setting device to calculate the roll position error. By using the signal, feedback control is performed so that the position of the presser roll is maintained according to the roll position setting signal.

Here, in order to control the thickness of the rolled material, when the roll gap between the upper and lower work rolls of the rolling mill is changed using a hydraulic reduction device, the tension applied to the rolled material changes.

Then, the tension meter of the tension control device detects the tension applied to the rolled material and sends a tension detection signal to the coefficient unit, and the coefficient unit multiplies the tension detection signal by the tension control gain to obtain a roll movement command.

The roll movement command is sent to the adder of the hydraulic cylinder control device and added to the roll steady position control command to correct the roll position control command, and the tension is adjusted in the same manner as above based on the corrected roll position control command. The hydraulic cylinder of the device is moved to extend and retract, and the presser roll is moved so that the tension on the rolled material remains constant.

According to the second aspect of the invention, the low-pass filter removes components higher than the corner frequency from the roll displacement signal detected by the displacement meter to obtain a steady roll displacement signal, and sets the roll position using an adder/subtractor to the steady roll displacement signal. The signal is added to obtain a roll position deviation signal, and the high-pass filter removes components below the corner frequency from the tension detection signal detected by the tension meter to obtain a tension fluctuation signal, and a coefficient multiplier is applied to the tension fluctuation signal. The tension control gain is multiplied by , and the roll movement command is obtained.

According to the third aspect of the present invention, the corner frequency of at least the high-pass filter of the high-pass filter and the low-pass filter is changed as necessary.

According to the invention of claim 4, the corner frequency calculator calculates the corner frequency change signal based on the rolling speed setting value from the rolling speed setter, and passes the corner frequency change signal to one of the high-pass filter and the low-pass filter. It is sent to at least a high-pass filter to change the corner frequency.

According to the invention of claim 5, the corner frequency change signal is obtained based on the rolling speed detection value from the corner frequency calculator or the speedometer, and the corner frequency change signal is passed through at least a high pass filter of a high pass filter and a low pass filter. Send it to a filter to change the corner frequency.

[Implementation example] Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the present invention.

Portions in the figure that are denoted by the same reference numerals as in FIG. 6 represent the same parts, and therefore their explanation will be omitted. Further, the hydraulic pressure lowering device 26, the mill constant control device 30, and the monitor AGC device 36 are similar to those shown in FIG. 6, but are omitted from FIG. 1 to simplify the drawing and explanation.

Five presser rolls 37, 38, 39, 40, 41 are arranged approximately horizontally so that the rolled material 1 can pass in a staggered manner on the entrance side of the rolling mill 10.゜4
Presser rolls 37 located at the center and both ends of 0.41.
39 and 41 are fixed, the remaining presser rolls 38 and 40 are supported by an elevating arm 42, and the elevating arm 42 is supported by a hydraulic cylinder 44 that expands and contracts in the vertical direction by supplying and discharging an operating body from a servo valve 43. This allows the presser rolls 38 and 40 to be moved up and down, and constitutes a tension adjustment device 45.

Incidentally, the tension adjusting device 45 may be provided on both the inlet side and the outlet side of the rolling mill 10.

A displacement meter 46 is attached to the lifting arm 42, and a low-pass filter 49 is provided to remove high frequency components of fluctuation from the roll displacement signal 47 detected by the displacement meter 46 to obtain a steady roll displacement signal 48, and the low-pass filter 49 outputs An adder/subtracter 53 is provided to obtain a roll position deviation signal 52 by taking the deviation between the roll steady displacement signal 48 and the roll position setting signal 51 set in the roll position setting device 50. A coefficient unit 55 for multiplying the signal 52 by a position control gain Kp to obtain a roll steady position control command 54 is provided, and a roll steady position control device 56 is provided.
Configure.

On the other hand, a tension meter 57 is attached to the presser roll 37 on the fixed side of the tension adjustment device 45, and a high-pass filter 60 removes low frequency components of fluctuation from the tension detection signal 58 detected by the tension meter 57 to obtain a tension fluctuation signal 59. and a coefficient unit 62 for multiplying the tension fluctuation signal 59 output by the high-pass filter 60 by a tension control gain Kt for converting the tension into a roll movement amount to obtain a roll movement command 61. Configure.

An adder 67 adds the roll steady position control command 54 output from the coefficient unit 55 and the roll movement command 61 output from the coefficient unit 62 to obtain a roll position control command 64.
is provided, and the roll position control command 64 outputted by the adder 67
A hydraulic cylinder control device 81 is provided with a servo amplifier 66 that obtains an opening adjustment command 65 to be output to the servo valve 43 based on the above.

In addition, G is a roll gap.

Next, the operation will be explained.

The process of rolling the rolled material 1 by the rolling mill 10, and the hydraulic reduction device 26 and mill constant control device 3 (not shown) during rolling.
The process of controlling the plate thickness of the rolled material 1 by the monitor AGC device 36 and the monitor AGC device 36 is the same as that shown in FIG. 6, so a description thereof will be omitted.

In the present invention, at the start of rolling, the presser roll 38 on the moving side is moved by the hydraulic cylinder 44 via the lifting arm 42.
40 is moved upward relative to the fixed presser rolls 37, 39, 41, the tension adjusting device 45 is kept open, and the rolled material 1 is passed therethrough.

The rolled material 1 is transferred to the five presser rolls 37 of the tension adjustment device 45.
3g, 39, 40.41, the roll position setting signal 51 is set in the roll position setting device 50, and the roll position setting signal 51 is passed through the adder/subtractor 53 as it is as the roll position deviation signal 52. 55, the coefficient unit 55 multiplies the roll position deviation signal 52 by the position control gain Kp to obtain the roll steady position control command 54, and the roll steady position control command 54 is passed through the adder 67 as it is as the roll position control command 64. Servo amplifier 6
6, and the servo amplifier 66 outputs the roll position control command 6.
4 into an opening adjustment command 65 and sends the opening adjustment command 65 to the servo valve 43. Then, the servo valve 43 adjusts the amount and direction of the actuating body to the hydraulic cylinder 44 in accordance with the opening adjustment command 65, causes the hydraulic cylinder 44 to contract, and sets the presser roll 38° 40 via the lifting arm 42. lower to position.

As a result, the rolled material 1 was rolled at 37.38°3 with five presser rolls.
9, 40, and 41 in a staggered manner, initial tension is applied to the rolled material 1.

At the same time, a displacement meter 46 attached to the lifting arm 42 detects the vertical position of the presser roll 38 , 40 and sends a roll displacement signal 47 to a low-pass filter 49 . The low-pass filter 49 has the characteristic of rapidly attenuating frequency components above the corner frequency ωc1, as shown in Figure 2, where the vertical axis represents the ratio of output to input and the horizontal axis represents frequency. , the roll displacement signal 4 detected by the displacement meter 46
7 is a roll steady displacement signal 48 from which high frequency components have been removed and which shows only the slow movement of the presser roll 38.40.
becomes. The roll steady displacement signal 48 is fed back to the adder/subtractor 53, and the deviation from the roll position setting signal 51 from the roll position setting device 50 is calculated to obtain a new roll position deviation signal 52. The roll position deviation signal 52 obtained in this way is sent to the coefficient multiplier 55 in the same manner as described above, and the roll position deviation signal 52 is multiplied by the position control gain Kp in the coefficient multiplier 55 to generate a roll steady position control command 55.
is determined, and the roll steady position control command 54 is sent to the adder 6.
7, the roll position control command 64 is sent as it is to the servo amplifier 66, and the servo amplifier 66 converts the roll position control command 64 into an opening degree adjustment command 65, which is then sent to the servo valve 43. As a result, the servo valve 43 adjusts the amount and direction of the actuating body to the hydraulic cylinder 44 according to the opening adjustment command 65, moves the hydraulic cylinder 44 to extend and contract, and moves the presser roll 38, 40 via the lifting arm 42. Adjust to the set position. In this way, the moving side presser roll 38.40
The relative displacement of the presser rolls 37, 39, 41 on the fixed side is suppressed, and the tension applied to the rolled material 1 is kept constant. Also, when the presser roll 38.40 is at the set position,
The value of the roll steady displacement signal 48 is the roll position setting signal 51
Since the value of the roll position deviation signal 52 becomes zero in agreement with the value of , the servo valve 43 closes and the presser roll 38, 40 comes to rest.

During rolling, if the position of the presser rolls 38, 40 changes due to leakage of the operating body from the servo valve 43 or temperature drift of the opening adjustment command 65 output from the servo amplifier 66, the presser rolls 38, 40 are changed as described above. is adjusted so that the position is the set position, and the tension applied to the rolled material 1 is prevented from changing.

Note that the position of the presser rolls 38 and 40 changes very slowly due to leakage of the operating body from the servo valve 43 and temperature drift of the opening adjustment command 65 output from the servo amplifier 66, so the low-pass filter 49 is Breaking point frequency ωe
By appropriately selecting 1, the presser roll 38.40
The above-described position control can be performed without being affected by tension fluctuations in the rolled material 1.

On the other hand, in order to control the thickness of the rolled material 1 during rolling, the sixth
Using the hydraulic lowering device 26 shown in the figure, the work roll 4.5 is
When the roll gap G between the rolls is changed, the tension gauge 57 provided on the presser roll 37 measures the fluctuation in the tension of the rolled material 1 due to the change in the roll gap G until the reel motor tension control device 11.12 responds. Detection and tension detection signal 58
is sent to the high-pass filter 60. high pass filter 60
has the characteristic of rapidly attenuating frequency components below the corner frequency ω, as shown in Figure 3, where the vertical axis represents the ratio of output to input and the horizontal axis represents frequency. The tension detection signal 58 detected by the total tension detection signal 57 has its low frequency components removed, and becomes a tension fluctuation signal 59 indicating only the quick movement of the presser roll 38, 40 due to tension fluctuation.

The tension fluctuation signal 59 is multiplied by a tension control gain Kt for converting the tension into a roll movement amount in a coefficient unit 62 to become a roll movement command 61, and the roll movement command 61 is multiplied by an adder 67 as the roll steady position control command. 54 and the roll position control command 64 is corrected, and the same control as described above is performed based on the corrected roll position control command 64.

As a result, the presser rolls 38 and 40 move around the set position so as to suppress fluctuations in tension, thereby maintaining the tension applied to the rolled material l constant.

It should be noted that the tension control device 63 of the present invention is intended for quick tension fluctuations from the time when the plate thickness is controlled using the high-speed hydraulic reduction device 26 until the reel motor tension control device 11, 12 responds. Therefore, by appropriately selecting the corner frequency ωc2 of the high-pass filter 60, it is possible to remove only rapid tension fluctuations without being affected by the position control.

FIG. 4 shows another example of the tension adjustment device 45, in which two presser rolls 68 and 69 are arranged one above the other, and a hydraulic cylinder 70 that extends and contracts in the horizontal direction is connected to the lower presser roll 69. There is. Even in this case, the tension of the rolled material 1 can be adjusted by moving the lower presser roll 69 in the horizontal direction.

FIG. 5 shows another embodiment of the present invention, in which the corner frequency ω. □
and a low-pass filter 71 that can change the corner frequency ωc.
A changeover switch 77 is provided to select either the rolling speed set value 74 from the rolling speed setting device 73 or the rolling speed detected value 76 from the speedometer 75 provided in the rolling line. When the signal is switched and inputted to the corner frequency calculator 78, the corner frequency calculator 78 selects the appropriate corner frequency ω. □ and ω. 2 and sends a corner frequency change signal 79.80 to the low-pass filter 71 and high-pass filter 72 to obtain the corner frequencies ωc1 and ω.
. The structure is similar to that of the embodiment shown in FIG. 1, except that 2 can be changed.

According to this embodiment, the optimal corner frequency ω6 and ω are always set according to the frequency of tension fluctuation that changes with the rolling speed.
The same functions and effects as the embodiment shown in FIG. 1 can be obtained except that c2 can be set. However, the influence of the rolling speed on the low-pass filter 71, which targets the steady displacement of the presser rolls 38 and 40, is affected by the high-pass filter 72.
Therefore, the low-pass filter 71 has a corner frequency ω
. □ may be fixed.

In the above embodiments, only the case where the present invention was applied to a reversible cold rolling mill with jingle stands was described, but it can also be applied to irreversible rolling mills that roll in one direction, tandem rolling mills with two or more stands, etc. The present invention can be applied to all rolling mills in which the problems described in the above-mentioned prior art occur, and each control device of the present invention can be configured with an electronic circuit including a low-pass filter and a high-pass filter. It goes without saying that it may be configured with a digital arithmetic unit, and that various other changes may be made without departing from the gist of the present invention.

[Effects of the Invention] As explained above, according to the present invention, the entrance side of the rolling mill,
Alternatively, tension adjustment devices are provided on both the input and output sides, and control is performed by a roll steady position control device, a tension control device, and a hydraulic cylinder control device, so that various excellent effects such as those described below can be achieved.

(2) According to the first aspect, the tension adjustment device can quickly suppress tension fluctuations on the entrance side or the entrance/exit side of the rolling mill that occur as a result of changing the roll gap of the rolling mill in order to control the plate thickness.

In addition, since the roll steady position control device can control the position of the presser roll on the moving side and the tension can be controlled using the tension controller, only the variation in tension can be controlled while the presser roll on the moving side is maintained at the initial setting position. Can be suppressed.

As a result of the above, the position of the presser roll on the moving side can be maintained stably during rolling without being affected by disturbances, and tension fluctuations that occur as a result of manipulating the roll gap can be quickly controlled, resulting in a response to thickness control. It is possible to speed up the process and obtain accurate product thickness.

According to claim 2, since a low-pass filter is provided, a steady-state roll displacement signal can be obtained by removing components higher than the break point frequency from the roll displacement signal detected by the displacement meter, and the high-pass filter is also provided. With this arrangement, the tension fluctuation signal can be obtained by removing the component below the corner frequency from the tension detection signal detected by the tension meter.

(2) According to claim 3, the corner frequency of at least the high-pass filter of the high-pass filter and the low-pass filter can be changed.

(2) According to claim 4, the corner frequency of at least the high-pass filter of the high-pass filter and the low-pass filter can be changed based on the rolling speed setting value from the rolling speed setting device.

(2) According to claim 5, the corner frequency of at least the high-pass filter of the high-pass filter and the low-pass filter can be changed based on the rolling speed detection value from the speedometer.

[Brief explanation of drawings]

Fig. 1 is a control system diagram of one embodiment of the present invention, and Fig. 2 is a control system diagram of an embodiment of the present invention.
A diagram showing the characteristics of the low-pass filter shown in Figure 3.
4 is a diagram showing another embodiment of the tension adjusting device, FIG. S is a control system diagram of another embodiment of the present invention, and FIG. A control system diagram of the plate thickness control device, FIG. 7 is a diagram showing the responsiveness of the plate thickness control device of FIG. 6. In the figure, 1 is a rolled material, 4.5 is a work roll, 10 is a rolling machine, 26 is a hydraulic rolling device, 37.3g, 39, 40, 41
, 68° 69 is a presser roll, 43 is a servo valve, 44.7
0 is a hydraulic cylinder, 45 is a tension adjustment device, 46 is a displacement meter, 47 is a roll displacement signal, 48 is a roll steady displacement signal,
49.71 is a low-pass filter, 50 is a roll position setter, 51 is a roll position setting signal, 52 is a roll position deviation signal, 53 is an adder/subtractor, 54 is a roll steady position control command, 55.62 is a coefficient unit, 56 is a Roll steady position control device, 57 is a tension meter, 58 is a tension detection signal, 59 is a tension fluctuation signal, 60.72 is a high pass filter, 61 is a roll movement command, 63 is a tension control device, 64 is a roll position control command, 65 is an opening adjustment command, 66 is a servo amplifier, 67 is an adder, a hydraulic cylinder control device, 73 is a rolling speed setter, 74 is a rolling speed setting value, 75 is a speedometer, 76 is a rolling speed detection value, and 78 is a folding point frequency calculator, 79.80 is the corner frequency change signal, Kp is the position control gain, Kt is the tension control gain, ω. □ is the corner frequency of the low-pass filter 49.71, ω. 2 indicates the corner frequency of the high-pass filter 60.72, and G indicates the roll gap.

Claims (1)

[Claims] 1) The tension of the rolled material is controlled by a presser roll connected to a hydraulic cylinder on the entry side or both the entry and exit sides of a rolling mill equipped with a hydraulic rolling device that sets the roll gap between the upper and lower work rolls. A tension adjustment device capable of adjusting the pressure is provided, and a displacement meter detects the amount of displacement of the presser roll, and the deviation between the roll displacement signal detected by the displacement meter and the roll position setting signal set in the roll position setting device is taken. a roll steady position control device comprising: an adder/subtracter for obtaining a roll position deviation signal using the adder/subtractor; and a coefficient unit for multiplying the roll position deviation signal from the adder/subtractor by a position control gain to obtain a roll steady position control command; A tension control device is provided that includes a tension meter that detects the tension applied to the rolled material, and a coefficient unit that multiplies the tension detection signal detected by the tension meter by a tension control gain to obtain a roll movement command, and further includes an adder that adds the roll steady position control command and the roll movement command from the coefficient unit to obtain a roll position control command; and a servo that supplies and discharges the actuating body to the hydraulic cylinder based on the roll position control command from the adder. A plate thickness control device for a rolling mill, comprising a hydraulic cylinder control device equipped with a servo amplifier that sends an opening adjustment command to a valve. 2) A low-pass filter that removes components above the break point frequency from the roll displacement signal detected by the displacement meter to obtain a steady roll displacement signal to be sent to the adder/subtractor, and a component below the break point frequency from the tension detection signal detected by the tension meter. 2. The plate thickness control device for a rolling mill according to claim 1, further comprising a high-pass filter for obtaining a tension fluctuation signal to be sent to a coefficient unit of the tension control device. 3) The plate thickness control device for a rolling mill according to claim 2, wherein at least the high-pass filter among the high-pass filter and the low-pass filter is capable of changing the corner frequency. 4) Based on the rolling speed setting value from the rolling speed setting device,
4. The plate thickness control device for a rolling mill according to claim 3, further comprising a corner frequency calculator for determining a corner frequency change signal to be sent to at least one of the high-pass filter and the low-pass filter. 5) The rolling mill according to claim 3, further comprising a corner frequency calculator for calculating a corner frequency change signal to be sent to at least one of a high pass filter and a low pass filter based on the rolling speed detected value from the speedometer. Plate thickness control device.