JPH04200913A - Device for controlling position of rolling mill - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention is designed to prevent the difference in sinking between the left and right rolling cylinders, which occurs when the rolled material is caught in the roll gap at the start of rolling. This invention relates to a position control device for a rolling mill.

[Prior Art] FIG. 6 is a diagram showing a conventional position control device for a rolling mill.
Inside the housing 1, upper and lower work rolls 3.4 for rolling down the rolled material 2 are provided so as to be movable up and down.
, 6.

Both ends of the lower back up roll 6 are placed between the housing 1 and the shaft box 7 that supports both left and right ends (work roll and drive side) of the lower back up roll 6.
A hydraulic pressure reduction device 12 is provided with a hydraulic pressure reduction cylinder 8 whose position is adjusted in two directions, and in which pressure oil from a tank 9 is supplied to and discharged from the hydraulic pressure reduction cylinder 8 via a pump 10 and a servo valve 11. ing.

Further, an electric lowering device 18 consisting of a motor 14, a worm 15, a worm wheel 16, and a lowering screw 17 is provided between the housing 1 and the axle box 13 that supports the upper backup roll 5.

Furthermore, a position detector 19 provided on the hydraulic pressure reduction cylinder 8
, a detection signal 22 from a position detector 21 provided on the lowering screw 17 , a load detection signal 24 from a load cell 23 provided on the axle box 13 of the upper backup roll 5 , and a roll gap A roll position control device 29 is provided which manually inputs a setting signal 26 from the setting device 25 and outputs command signals 27 and 28 to the servo valve 11 and the motor 14, respectively.

In the figure, 30 and 31 are axle boxes of the upper and lower work rolls 3 and 4, and 33 is a piston of the hydraulic pressure reduction cylinder 8.

In such a rolling mill, the roll position control device 29 operates based on the setting signal 26 from the roll gap setting device 25.
First, a command signal 28 is sent to the motor 14 of the electric lowering device 18.
After roughly setting the initial roll gap by sending a command signal to drive the reduction screw 17, a command signal 27 is sent to the servo valve 11 of the hydraulic reduction device 12 to drive the quick-response hydraulic reduction cylinder 8. Control the roll gap during rolling with high precision.

At this time, the position of the hydraulic pressure reduction cylinder 8 and the position of the pressure reduction screw 17 are determined by position detectors 19 provided respectively.
Feedback control is performed based on detection signals 20 and 22 from 21.

Further, the roll replacement is performed by widening the roll gap using an electric rolling down device 18 that can obtain a large stroke.

[Problems to be Solved by the Invention] As described above, the electric lowering device 18 and the hydraulic lowering device 1
The reason why 2 is provided twice is because when using a long stroke hydraulic pressure reduction cylinder 8, there was a problem as shown below.

That is, as shown in FIG. 7, if the cross-sectional area of the hydraulic pressure reduction cylinder 8 is S1, the oil column height is L1, and the bulk elastic modulus of the oil is K, then the flexural spring constant of the oil in the hydraulic pressure reduction cylinder 8 is KX
It is expressed as S÷, and the spring constant is the hydraulic pressure reduction cylinder 8.
As the stroke becomes longer, the oil column height increases, so the value becomes smaller and the spring becomes softer, making it easier for the piston 33 of the hydraulic pressure reduction cylinder 8 to sink. The shorter the oil column height L becomes, the larger the value becomes, the harder the spring becomes, and the piston 33 of the hydraulic pressure reduction cylinder 8 increases.
becomes difficult to sink into.

That is, when the rolled material 2 is caught in the rolling mill, the hydraulic reduction cylinder 8 sinks in accordance with the value of the above-mentioned spring constant, causing a variation in the roll gap. Especially in the case of hot rolling,
There is always a temperature difference between the left and right sides of the rolled material 2, so that the rolling load at the time of biting varies between the left and right sides by about several percent of the total load. When the stroke of the hydraulic reduction cylinder 8 is long, the spring constant becomes small, so the difference in the amount of depression between the left and right sides due to the difference in rolling load becomes large, and the rolled material 2
In this case, there is a possibility that a difference in thickness between the left and right ends occurs, causing the rolled material 2 to meander or to make it impossible to pass the rolled material 2 to the subsequent rolling mill.

Therefore, in conventional rolling mills, the roll gap is not controlled only by the hydraulic reduction cylinder 8 with a long stroke, but in order to prevent the hydraulic reduction cylinder 8 from sinking, the hydraulic reduction cylinder 8 with a short stroke and a large spring constant is used. At the same time, it was necessary to use an electric lowering device 18 in order to compensate for the lack of stroke.

FIG. 8 is a diagram showing the results of a computer simulation conducted to examine the degree of the difference in the amount of left and right sinking caused by the hydraulic pressure reduction cylinder 8. This is a simulation of the phenomenon for about 12 seconds after the rolled material 2 gets caught in the roll gap at time 0 seconds, and the oil column height L is 75 mm.
, it is assumed that there is a 3% difference in rolling load between the left and right sides.

According to Fig. 8, the rolling load is on the line a after the rolled material 2 is bitten.
However, since the rolling load is suddenly generated, the pistons 33 of the left and right hydraulic pressure reduction cylinders 8 sink due to the above-mentioned reason. If left as is, the thickness of the rolled material 2 will vary in the longitudinal direction, so in order to prevent this, the roll gap is narrowed down by a certain amount in advance to reduce the pressure of the hydraulic pressure reduction cylinder 8 that occurs when the rolled material 2 is caught. Roll gap subsidence compensation, as shown in the line, is normally performed to control the roll gap to return to the set value when the amount of subsidence reaches its maximum. To compensate for roll gap sinking, the opening degrees of the left and right servo valves 11 are line C,...
, d.

The positions of the left and right hydraulic pressure reduction cylinders 8 indicated by the detection signal 20 from the position detector 19 provided on the hydraulic pressure reduction cylinders 8 are as shown by lines e and f, and if the left and right difference is taken, the positions of the hydraulic pressure reduction cylinders 8 are The difference between the left and right positions is as shown by line g, and a maximum value occurs. This h is 9 in this calculation example.
It can be seen that it is 5 μm and lasts for more than 0.1 seconds.

In view of the above-mentioned circumstances, the present invention makes it possible to prevent the difference in sinking between the left and right rolling cylinders from occurring when the rolled material bites into the roll gap at the start of rolling. It is an object of the present invention to provide a position control device for a rolling mill that allows the roll gap to be controlled without any trouble using only a roller.

[Means for Solving the Problems] The invention of claim 1 provides hydraulic reduction cylinders 8 for adjusting the roll gap 32 of the upper and lower work rolls 3.4 independently on the work side A and the drive side B of the rolling mill 1. ．．
8°, and servo valves 11° and 11°, which supply and discharge pressure oil based on the opening commands 48 and 49 from the servo up 40 and 40°, are connected to the hydraulic pressure reduction cylinders 8 and 8, respectively. Position detectors 19 and 19' for directly or indirectly measuring the distance between the gaps 32 are provided individually on the work side A1 and the drive side B.
' output signal 20°20'' and roll gap setting device 2
Comparators 35 and 35' are provided which manually calculate deviation signals 36 and 36' from work side A1 and drive side B by manually inputting setting signals 26 and 26' from 5 and 25'. Coefficients 37 and 37° are provided to multiply 36° by the position control gain Kg, and the output signal 20' of the position detector 19° of the drive side B is subtracted from the output signal 20 of the position detector 19 of the work side A. , conversely, a comparator 46 is provided which subtracts the output signal 20 of the position detector 19 on the work side A from the output signal 20° of the position detector 19 on the drive side B.
A coefficient unit 47 is provided on the work side A to multiply the output signal 45 of the coefficient unit 45 by a left/right difference correction gain Kd, and the output signal 39 of the coefficient unit 47 is subtracted from or conversely added to the output signal 38 of the coefficient unit 37 to output the servo. Command signal 4 sent to up 40
A subtracter 42 or an adder 44 for calculating 1 or 43 is provided on the drive side B, and the output signal 39 of the coefficient unit 47 is added to or subtracted from the output signal 38'' of the coefficient unit 37° to increase the servo. Command signal 4 to send to 40°
The present invention relates to a position control device for a rolling mill characterized by being provided with an adder 44 or a subtracter 42 for calculating 3 or 41.

The invention of claim 2 provides an output signal 38 of the coefficient multiplier 37, 37'.
, 38' and the output signal 39 of the coefficient unit 47, and an adder 4 for adding and subtracting or conversely subtracting and adding the output signal 39 of the coefficient unit 47.
4. A position control device for a rolling mill in which limiters 50 and 50' are provided between the subtracter 42 and the coefficient unit 37, 37' to limit the output signal 38.38° of each coefficient unit 37, 37' for a certain period of time. This applies to

[For production] According to the invention of claim 1, it operates as follows.

Setting from the output signal 20.20° of the position detector 19.19' which directly or indirectly measures the distance between the roll gaps 32 provided individually on the work side A1 and the drive side B and the roll gap setting device 25.25'. signal 26
．． 26' are input to comparators 35 and 35', and deviation signals 36.
36' is obtained, and a coefficient multiplier 37 is applied to each individual difference signal 36.36'.
．． Multiply the position control gain Kg at 37'.

On the other hand, the comparator 46 converts the output signal 20 of the position detector 19 of work side A to the position detector 19' of tribe side B.
The output signal 20' of the output j signal 20' is subtracted, or conversely, the output signal 20 of the position detector 19 of the work side A is subtracted from the output signal 20' of the position detector 19' of the drive side B, and the output of the comparator 46 is The signal 45 is multiplied by the left-right difference correction gain by d in the coefficient multiplier 47, and on the work side A, the output signal 39 of the output J signal 47 from the coefficient multiplier 47 is multiplied by the subtracter 42 or the adder 44. A command signal 41 that is subtracted from or added to the output signal 38 and sent to the servo up 40
Alternatively, 43 is calculated, and on the drive side B, the adder 44 or the subtracter 42 outputs the output signal 39 of the coefficient unit 47.
is added to or subtracted from the output signal 38' of the coefficient unit 37' to calculate the command signal 43 or 41 sent to the servo up 40' based on the opening command 48.49 from the servo up 40.40'. The servo valves 11 and 11' supply and discharge pressurized oil to the hydraulic pressure reduction cylinders 8 and 8', and the work side A of the rolling mill 1 is controlled by the hydraulic pressure reduction cylinders 8 and 8'.
and upper and lower work rolls 3 and 4 on drive side B
The roll gaps 32 of the roll gaps 32 are adjusted independently.

According to the invention of claim 2, an adder 44 that adds and subtracts or conversely subtracts and adds the output signals 38 and 38' of the coefficient multipliers 37 and 37' and the output signal 39 of the coefficient multiplier 47, respectively; A limiter 50.50' provided between the subtracter 42 and the coefficient multiplier 37.37' limits the output signal 38.38' of each of the coefficient multipliers 37.37' for a certain period of time.

This prevents the effect of the correction by the output signal 39 of the coefficient multiplier 47 from being reduced by the output signal 38.38' of the coefficient multiplier 37.37'.

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

1 to 3 show an embodiment of the present invention.

In addition, the basic configuration of the rolling mill etc. and the details of each component in the figure include the same ones as those shown in Figures 6 to 8, so the same components are the same. The explanation will be omitted by assigning the reference numeral , and only the configuration specific to the present invention will be explained below.

In FIG. 1, an electric rolling down device is not provided, and the roll position is controlled only by a hydraulic rolling down device 12 provided with a hydraulic rolling down cylinder 8 having a long stroke.

In addition, 32 in FIG. 1 indicates the roll gap between the work rolls 3.4.

FIG. 2 is a block diagram of the roll position control device 34 shown in FIG. 1. For convenience of explanation "In Figure 2" The three sides are the work side A side of the rolling mill, the lower side is the drive side B side,
Identical products are distinguished by a dash on the drive side B side.

Setting signals 2 are sent from roll gap setting devices 25 and 25' on the work side A side and the drive side B side, respectively.
6, 26° and a detection signal 20.20'' from a position detector 19.19' provided on the hydraulic pressure reduction cylinder 8.8', and calculates a deviation signal 36.36'.
5.35' is provided, and the deviation signal 36.36' from the comparator 35.35' is multiplied by the position control gain Kg to produce an output signal 38°3 which becomes a position correction signal for the hydraulic pressure reduction cylinders 8, 8'.
A coefficient multiplier 37.37'' is provided on the work side A side to calculate the difference between the output signal 38 from the coefficient multiplier 37 and the output signal 39 from the coefficient multiplier 47, which becomes a left-right difference correction signal to be described later. A subtracter 42 is provided to obtain a command signal 41 to be sent to the up drive 40, and a coefficient unit 37° is provided on the drive side B side.
The output signal 39 of the coefficient multiplier 47 is added to the output signal 38' from the
An adder 44 is provided to obtain a command signal 43 to be sent to the servo-up 40" by adding the output signal 2 to the output signal 43 of the position detector 19 on the work side A side using the comparator 46 as described later.
In order to subtract the output signal 20' of the position detector 19' on the drive side B side from 0, a subtracter 42 is provided on the work side A side and an adder 44 is provided on the drive side B side. When the output signal 20 on the work side A side is subtracted from the output signal 20' on the B side, the work side Δ side becomes the adder 44 and the drive side B side becomes the subtracter 42).

Then, from the output j signal 20 from the position detector 19 on the work side A side, the output signal 20 is sent to the position detector 19' on the drive side B side.
A comparator 46 for subtracting the output signal 20' from the comparator 46 is provided, and the left-right difference correction control gain K is added to the output signal 45 from the comparator 46.
A coefficient multiplier 47 is provided for multiplying by d to obtain the output signal 39.

Note that 48.49 is an opening command sent from the servo up 40 to the servo valve 11.

Next, the effect will be explained.

Setting signals 26, 26 from roll gap setting device 25, 25' on work side A side and drive side B side
The comparator 35.35' compares and calculates the output signal 20.20' of the position detector 19.19° and the deviation signal 36°3.
6' is obtained, and the deviation signals 36, 36° are sent to the coefficient multiplier 37.
The output signal 38°3 is multiplied by the position control gain Kg at °37' and becomes a position correction signal for the hydraulic pressure reduction cylinders 8, 8'.
8'. The output signal 38 passes through a subtracter 42 on the work side A side, and an adder 44 on the drive side B side to become command signals 41 and 43, respectively.
It is input to servo up 40, 40'. From the servo up 40.40'', an opening command 48.49 based on the command signal 41.43 is output to the servo valves 11, 11°, the opening of the servo valves 11, 11' is adjusted, and the hydraulic pressure reduction cylinder 8 , 8' is controlled, and the hydraulic pressure reduction cylinder 8.8' is extended and retracted to control the position of the work roll 4.4' independently on the work side A side and the drive side B side. Ru.

Position detector 19 provided on the hydraulic pressure reduction cylinder 8.8'
．． 19' detects the position of the piston 33 of the hydraulic pressure reduction cylinder 8.8°, and the output signal 20.20' from the position detector 19, 19' is fed back to the comparator 35.35°, Position detector at 19.19'
output signal from 20.20° and roll gap setting device 2
The setting signal 26.26' from 5.25' is compared to obtain a deviation signal 36.36'. The deviation signal 36,
36°, the position of the work roll 4 is controlled in the same way as above, and when the deviation signal 36 and 36° become O, the opening command 48.49 becomes 0 and the servo valve 11.11'
is closed, and the position setting of the work roll 4 is completed.

As a result, the initial setting of the roll gap is performed.

Then, at the start of rolling, the same work roll 4 as above
At the same time, the output signal 20 from the position detector 19 provided on the hydraulic reduction cylinder 8 on the work side Δ side and the position sensor 19 provided on the hydraulic reduction cylinder 8 on the drive side B side are controlled. Output signal 20 from '
The output horn signal 45 from the comparator 46 is multiplied by the left-right difference correction control gain Kd in the coefficient multiplier 47, and on the work side A side, the subtracter 42 uses the coefficient multiplier 3
The command signal 41 is obtained by subtracting the output signal 39 of the coefficient multiplier 47 from the output signal 38 of the coefficient multiplier 7, and on the drive side B side, an adder 44 adds the output signal 38' of the coefficient multiplier 37 to the output signal 38' of the coefficient multiplier 4.
7 is added to obtain a command signal 43, and the position of the work roll 4 is controlled in the same manner as described above based on the command signals 41 and 43 thus obtained.

Then, on the work side A side, the output signal 3 of the coefficient multiplier 47
9 (left-right difference correction signal) is subtracted, and at the same time, on the drive side B side, the workpiece is reduced by the amount by which the output signal 39 (left-right difference correction signal) of the coefficient unit 47 is added. Since the amount of displacement of the roll 4 is increased, the difference between the left and right positions of the work roll 4 is reduced.

When the difference between the left and right positions of the work roll 4 becomes O, the coefficient multiplier 4
The output signal 39 of No. 7 also becomes O, and the left-right difference correction control ends.

FIG. 3 is a diagram showing the results of a simulation conducted to confirm the effects of the present invention.

The changes a in rolling load and compensation for roll gap depression are the same as in FIG. 8.

According to FIG. 3, when the rolled material 2 is bitten, the opening degrees of the left and right servo valves 11, 11° change as shown by the line 1% J, and the position detectors 19 provided in the hydraulic reduction cylinders 8, 8' ，
The position of the piston 33 of the left and right hydraulic pressure reduction cylinders 8, 8', indicated by the output signal 20, 20° from 19°, is approximately equal to the line 1, as shown at 1. The left-right difference in the position of the piston 33 of the hydraulic pressure reduction cylinder 8.8° is the line m
The maximum value n is less than half the maximum value in FIG. 8 (41 μm in this calculation example).

4 and 5 show a second embodiment of the present invention, in which the space between the coefficient multiplier 37 and the subtracter 42 on the work side A side, and between the coefficient multiplier 37' and the adder 44 on the drive side B side The output signal 3 of the coefficient multiplier 37 and 37' serves as a position correction signal for a certain period of time from the start of biting of the rolled material 2.
A limiter 50, 50° is provided to reduce the output signal 38 to, for example, about 80% and return the output signal 38 to 100% after a certain period of time has elapsed.

According to this embodiment, when the rolled material 2 is bitten, the comparator 35
．． Since a large deviation signal 36.36' is generated at 35', the opening degree of the servo valve 11.11' is 100% saturated with only the output signals 38 and 38' of the coefficient multiplier 37.37°, and the output of the coefficient multiplier 47 is It is possible to prevent the left-right difference correction control by the signal 39 from becoming ineffective by narrowing down the output signal 38 of the coefficient unit 37, 37' for a certain period of time when the rolled material 2 is biting, and it is possible to reliably perform the left-right difference correction control. can.

FIG. 5 is a diagram showing the results of a simulation conducted to confirm the effects of this example.

The changes a in rolling load and compensation for roll gap depression are the same as in FIGS. 3 and 8.

According to FIG. 5, when the rolled material 2 is bitten, the opening degrees of the servo valves 11 and 11 degrees on the work side A side and the drive side B side change as shown by lines o and p, and the hydraulic reduction cylinders 8 and 8 The positions of the pistons 33 of the left and right hydraulic pressure reduction cylinders 8, 8°, indicated by the detection signals 20, 20' from the position detectors 19° and 19° provided at 19° and 8°, respectively, are approximately equal as shown by lines q and r. The left-right difference in the position of the piston 33 of the hydraulic pressure reduction cylinder 8, 8° is shown by the line S, and the maximum value t
is approximately half of the maximum value n in Figure 3 (24 μm in this calculation example)
, decreased to approximately -4 of the maximum value shown in FIG. 8, and the difference between the left and right sides completely disappeared in 0.06 seconds after the rolled material 2 was bitten.

Other than the above, this embodiment has the same structure as the embodiment described above, and can obtain the same functions and effects.

It should be noted that the present invention is not limited to the above-described embodiments, and that the position control device can be implemented either by hardware using an electronic circuit or by software such as a computer or a sequencer, or by a combination of both. It goes without saying that the present invention may be applied to a rolling mill equipped with an electric rolling device and a hydraulic rolling device, and that various other changes may be made without departing from the gist of the present invention. be.

[Effects of the Invention] As explained above, according to the inventions of claims 1 and 2, the difference in sinking between the left and right rolling cylinders, which occurs when the rolled material is caught in the roll gap at the start of rolling, can be reduced. This provides an excellent effect in that the roll gap can be controlled without any trouble using only the hydraulic reduction cylinder with a long stroke.

Moreover, according to the invention of claim 2, since the limiter is provided,
An excellent effect can be achieved in that the difference in sinking between the left and right reduction cylinders can be reliably prevented.

[Brief Description of the Drawings] Fig. 1 is a side view of the first embodiment of the present invention, and Fig. 2 is a side view of the first embodiment of the present invention.
3 is a diagram showing the simulation results for FIG. 1, FIG. 4 is a block diagram of the position control device in the second embodiment of the present invention, and FIG. Figure 6 shows the simulation results for
7 is a diagram showing the elastic modulus of the hydraulic pressure reduction cylinder of FIG. 6, and FIG. 8 is a diagram showing the simulation results for FIG. 6. In the figure, 1 is the housing of the rolling mill, 3.4 is the work roll,
8.8' is a hydraulic pressure reduction cylinder, 11.11' is a servo valve, 19.19' is a position detector, 20.20' is an output signal, 25.25' is a roll gap setting device, 26.26'
is the setting signal, 32 is the roll gap, 35.35' is the comparator, 36.36' is the deviation signal, 37.37° is the coefficient unit, 38.38° is the output signal, 39 is the output signal, 40,4
0° is servo up, 41.43 is a command signal, 42 is a subtracter, 44 is an adder, 45 is an output signal, 46 is a comparator,
47 is a coefficient unit, 48.49 is an opening command, 50.50' is a limiter, A is a work side, B is a drive side, K
g indicates a position control gain, and Kd indicates a left-right difference correction control gain.

Claims (1)

[Claims] 1) Hydraulic reduction cylinders 8 and 8' for adjusting the roll gap 32 between the upper and lower work rolls 3 and 4 are provided independently on the work side A and the drive side B of the rolling mill 1, and Servo up 40, 40' to reduction cylinders 8, 8'
Servo valves 11 and 11' that supply and discharge pressure oil based on opening commands 48 and 49 from the workpiece are connected, respectively, and position detectors 19 and 19' that directly or indirectly measure the roll gap 32 interval are connected to the workpiece. The output signals 20 of the position detectors 19 and 19' are provided separately on side A and drive side B.
20' and setting signals 26, 26' from the roll gap setters 25, 25' are inputted to comparators 35, 35' for independently obtaining deviation signals 36, 36' on work side A and drive side B, respectively. and each deviation signal 36, 36'
Coefficient multipliers 37 and 37' for multiplying the position control gain Kg by the position control gain Kg are provided, and the output signal 20 of the position detector 19 on the work side A is used to output the output signal 20 from the position detector 19' on the drive side B.
A comparator 46 is provided to subtract the output signal 20' of the position detector 19 of the work side A from the output signal 20' of the position detector 19' of the drive side B. 46 is provided with a coefficient multiplier 47 which multiplies the output signal 45 of the coefficient multiplier 46 by a left-right difference correction gain Kd.
A subtracter 42 or an adder 44 is provided to calculate the command signal 41 or 43 to be sent to the servo up 40 by subtracting or adding it to the output signal 38 of the output signal 38. A rolling mill characterized in that an adder 44 or a subtracter 42 is provided for calculating a command signal 43 or 41 which is added to or subtracted from the output signal 38' of the coefficient unit 37' and sent to the servo up 40'. position control device. 2) An adder 44, a subtracter 42, and a coefficient unit 37 that add and subtract, or conversely subtract and add, the output signals 38, 38' of the coefficient units 37, 37' and the output signal 39 of the coefficient unit 47, respectively. , 37', a limiter 50 that limits the output signals 38, 38' of the coefficient multipliers 37, 37' for a certain period of time.
, 50'. A position control device for a rolling mill according to claim 1.