JPH0515922A - Method for controlling hydraulic rolling down of rolling mill and hydraulic rolling down device - Google Patents

Abstract

PURPOSE:To make efficient microadjustment of a quantity of oil and to improve rolling accuracy by setting a clearance between rolls of a rolling roll, comparing a set value with a measured value and calculating them and mounting two flow rate regulating valves controlled by the output in parallel to an oiling system. CONSTITUTION:When the clearance between the rolling rolls is set to a setter 1 and an oil pump 2 is started, the oil of an oil tank 3 is supplied by the oil pump 2 to a hydraulic rolling down cylinder 7 on the bearing 6 of the rolling roll. On one hand, the position of a bearing 6 of the rolling roll is measured by a magnetic position detector 9 fixed at the rolling stand 8 and the output is inputted to a comparison computing element 10. Then, the set value and the measured value of the magnetic position detector 9 are calculated by a comparison computing element 10, the output is received by a pulse controller 15, then, the output pulses are inputted respectively to stepping motors 13, 14 of the flow rate control valves 11, 12. Therefore, the stepping motors 13, 14 accurately control a quantity of passed oil of an oil control valves 11, 12 in proportion to pulses.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic pressure reduction control method for a rolling mill and a hydraulic pressure reduction method for the purpose of comparing and operating a set value and a measured value of a rolling roll gap and adjusting the rolling roll gap by the output thereof. Regarding the device.

[0002]

2. Description of the Related Art Conventionally, as a hydraulic pressure reducing device for a rolling mill,
There is known an invention (Japanese Patent Publication No. 58-23162) in which an elastic body is interposed when the movable part of the position detector of the hydraulic roll is pressed against the movable part of the hydraulic cylinder in order to control the rolling of the rolling roll. ing. Further, in controlling the roll gap, an oil flow velocity detector, and a flow velocity control circuit that takes the deviation between this detection signal and the flow velocity reference signal and outputs a reference signal of an operating current that controls the opening of the servo valve. Of a hydraulic pressure reduction control device in which a flow velocity control loop consisting of (1) is provided so that the gain of the flow velocity control system becomes constant (Japanese Patent Publication No. 61-138).
No. 85) is also known. Furthermore, a roll roll position setter, an integrator that integrates the output difference of the moving position detector, a pulse generator, a pulse counter, a pulse digital-analog converter, and the integrator and converter. An automatic leak compensation system for a hydraulic pressure rolling mill comprising a comparator for comparing output signals and a circuit means for generating an addition pulse or a subtraction pulse corresponding to the output signal of the comparator, and adding the output to a servo valve signal. Invention of control device (Japanese Patent Publication No. 59-5)
No. 0407) is known.

[0003]

The above-mentioned conventional inventions are all complicated devices used in large rolling mills, and it is presumed that each of them has achieved results. It is difficult to make the rolling mill a versatile control device. In particular, it has been difficult to control the rolling roll gap with high accuracy (for example, accuracy of 1/1000 mm or more) easily by moving a small amount of pressurized oil, and it was not possible to see the actual example so far. .

[0004]

SUMMARY OF THE INVENTION Therefore, according to the present invention, the rolling roll gap setting means and the measuring means are connected to the comparison calculation means, and two outputs of the flow rate adjusting means whose outputs are opposite to each other in the flow direction are provided. The above-mentioned conventional problems have been solved by interposing the same in the oil supply system and adding / subtracting the input oil amount.

That is, the present invention sets a roll gap of a rolling roll, calculates a deviation between the set value and a measured value of the roll gap, and controls the roll gap by the output thereof. A method for controlling hydraulic reduction of a rolling mill, characterized in that pressurized oil having a positive and negative flow rate difference controlled by the output of the calculation is applied to the reduction cylinder. The pressurized oil having a positive and negative flow rate difference is generated by applying pressurized oil in opposite flow directions to the hydraulic pressure reduction cylinder.

Another method is to set the roll gap of a rolling roll and calculate the deviation between this set value and the measured value of the roll gap and the deviation between the set value and the measured value of the thickness of the rolled material immediately after rolling. Then, in the method of controlling the roll gap by the output thereof, the rolling mill is characterized in that pressurizing oil having a positive and negative flow rate difference controlled by the output of the calculation is applied to the hydraulic pressure reduction cylinder of the rolling roll. Is a hydraulic pressure reduction control method.

Next, in the invention of the apparatus, the roll gap setting means of the rolling rolls and the measuring means are connected to the comparison calculation means of the both means, and the flow direction reciprocity controlled by the output of the comparison calculation means. The hydraulic pressure reduction control device for a rolling mill is characterized in that the two flow rate adjusting means are interposed in parallel with the oil supply system of the hydraulic pressure reduction cylinder of the rolling roll. The roll gap measuring means is a magnetic position detector. Further, the flow rate adjusting means is a flow rate adjusting valve.

The roll gap measuring means is a magnetic position detector (Magnescale), and the measuring rod of the magnetic position detector is located between the bearing of the upper rolling roller and the upper stand and between the stands lifted from the machine base. Between the upper and lower rolling rollers. Next, the flow rate control means
The discharge side of the constant discharge pump is connected to the suction side of the variable discharge pump and the supply / discharge pipe of the hydraulic pressure reduction cylinder, and the set value of the roll gap and the measured value are set in the discharge control circuit of the variable discharge pump. It is characterized in that the calculation output of the deviation between and is connected. Further, the flow rate adjusting means has a constant rotation motor and a constant discharge pump in parallel, and a variable rotation motor and a variable discharge pump in parallel, and connects the discharge side of the constant discharge pump to the suction side of the variable discharge pump and the hydraulic pressure reduction cylinder. The suction side of the constant discharge pump and the discharge side of the variable discharge pump are connected to an oil tank.

As described above, in the present invention, the two flow rate control valves are used with good volumetric efficiency to control the flow rate, and the difference in the flow rates is used as the feed oil amount. Can be controlled accurately, yet most efficiently and easily.

Next, instead of the flow rate control valve, a variable discharge pump may be used, or a variable speed motor may be used to change the discharge amount of the pump.

The adjustment of the present invention is 1/1000 mm to 5 mm
Since the accuracy of the position can be obtained, the elasticity of the rolling stand is naturally problematic. For example, in the case of a cast steel rolling stand, the elastic strain is different between the lower portion and the upper portion during casting, so that the correction must be made. Since this correction becomes complicated by incorporating the difference in elastic strain, it is easier and more practical to deal with the difference in elastic strain of the rolling stand by adjusting the height of the measuring point.

That is, the measurement of the rolling gap is carried out between the rolling stand and the bearing of the upper rolling roll, but the height of the measuring point of the rolling stand is taken into consideration in consideration of the difference in elastic strain of the rolling stand measured in advance. Since the elastic strains (influenced strains) of the left and right rolling stands are almost the same, it can be practically supplemented as the upper and lower sides of the bearing of the rolling roller (thus, the amount of the roller gap).

[0013]

The present invention sets the roll gap of the rolling rolls,
Since the set value and the measured value are compared and calculated, and two flow rate control valves controlled by the output are installed in parallel in the oil supply system,
Rolling accuracy can be improved because the amount of oil can be adjusted minutely and efficiently.

Since the differential oil amount by the two flow rate control valves is given to the hydraulic pressure reduction cylinder of the rolling roll, the flow rate control valve can be used with the best volume efficiency.

[0015]

[Embodiment 1] A hydraulic pressure reduction control method of the present invention will be described with reference to FIG.

When the rolling roll gap is set in the setting device 1 and the oil pump 2 is started, the oil in the oil tank 3 is moved by the oil pump 2 as shown by arrows 4 and 5 in the rolling roll bearing 6
It is supplied to the upper hydraulic pressure reduction cylinder 7. On the other hand, the position of the bearing 6 of the rolling roll is measured by the magnetic position detector 9 fixed to the rolling stand 8 (measurement of roll gap),
The output becomes the input of the comparison calculator 10. Therefore, after the set value and the measured value of the magnetic position detector 9 are calculated by the comparison calculator 10 and the output thereof is received by the pulse controller 15, the output pulse thereof is output by the oil amount control valves 11, 12. Input to the stepping motors 13 and 14, respectively. Therefore, the stepping motors 13 and 14 accurately control the oil passage amount of the oil amount control valves 11 and 12 in proportion to the pulse. The oil amount control valve 11 allows pressurized oil to flow as indicated by arrows 4 and 5,
The oil amount control valve 12 allows the pressurized oil to flow as indicated by arrows 16 and 17. Therefore, when receiving a signal to reduce the gap between the rolling rolls, the oil amount control valve 11 passes more oil than the oil amount control valve 12, so that the ram 7a of the hydraulic pressure reduction cylinder 7 descends.
On the other hand, in order to increase the rolling roll gap, the oil quantity control valve 1
If the oil quantity of the oil quantity control valve 12 is made larger than the oil quantity of No. 1 and the pressurized oil in the hydraulic pressure reduction cylinder 7 is returned to the oil tank 3 as indicated by arrows 16 and 17, the hydraulic pressure reduction cylinder 7 becomes Therefore, the amount of pressure oil is reduced and the ram 7a rises.

As described above, the amount of oil fed to the hydraulic pressure reduction cylinder 7 is controlled by the opening degree of the oil amount control valves 11 and 12, so that both the oil amount control valves 11 and 12 have the best volume efficiency. It can be controlled in points. Therefore, the accuracy of product thickness control can also be improved.

[0018]

[Embodiment 2] The embodiment of FIG. 2 is similar to the embodiment of FIG.
The thickness immediately after rolling of No. 3 is measured, the set value of the thickness setting device 24 and the measured value of the thickness measuring device 25 are compared by the comparator 26, and the output is input to the comparison calculator 10. It was done. The configuration and operation of the comparison arithmetic unit 10 and below are the same as those in the first embodiment, and the description thereof is omitted.

[0019]

[Embodiment 3] FIG. 3 shows an embodiment applied to a rolling mill.

That is, the rolling roll 2 is placed in the rolling stand 8.
0, 20a are installed, the hydraulic pressure reduction cylinder 7 is interposed between the bearing 6 of the rolling roll 20 and the rolling stand 8, and the magnetic position detector main body 9a is fixed to one side of the rolling stand 8.
The measuring rod 9b is brought into contact with the measuring projection 21 of the bearing 6. Reference numerals 22 and 22 in the figure denote counterpressure cylinders interposed between the bearing 6 and the bearing 19 of the rolling roll 20a, and have an action of maintaining a rolling gap under no load.

In the above, when the roll roll gap is set by the setting device 1 and the pump 2 is started, the oil amount control valves 11, 1 are set.
2, the amount of protrusion of the ram 7a is determined. Therefore, when the rolled material 23 is fed, the gap between the rolling rolls changes. Therefore, this is measured by the magnetic position detector 9, and if there is a difference between the measured value and the set value, the output of the comparison calculator is output as a pulse signal. Then, this is given to the stepping motors 13 and 14 to control the oil amount control valves 11 and 12, and the hydraulic pressure reduction cylinder 7 is controlled by adjusting the amount of oil supply. Therefore, the rolling rolls 20 and 20a
Since the gap is always kept constant, the rolling accuracy can be improved. When the rolling roll gap becomes small due to the thermal expansion of the rolling rolls 20 and 20a and the rolled product becomes thin, the thickness measuring device 2 immediately after the rolling of the rolled material 23 is performed.
The set value can be corrected by the output of 5.

As described above, it is possible to obtain a highly accurate rolled product by controlling both the thickness precision of the product due to the thickness of the raw material and the thickness precision of the product due to thermal expansion of the rolling roll and other factors.

[0023]

Fourth Embodiment An embodiment of hydraulic pressure adjustment will be described with reference to FIG.

Rolls 20, 20 are placed in the rolling stand 8.
A is installed, and the hydraulic pressure reduction cylinder 7 is interposed between the bearing 6 of the rolling roll 20 and the rolling stand 8. On the other hand, the pressurized oil has a constant discharge amount pump 28 and a variable discharge amount pump 29 connected to both shafts of a motor 27, and a discharge pipe 30 of the constant discharge amount pump 28 and a suction pipe 31 of the variable discharge amount pump 29.
The variable discharge pump 29 is provided with a controller 32 connected to the output of the measured value of the pressure roll gap. In the figure, 33 is a suction pipe of the constant discharge pump 28,
Reference numeral 34 is a discharge pipe of the variable discharge pump 29, and 42 is an oil tank.

In the above embodiment, when the motor 27 is started and both pumps 28 and 29 are driven, pressurized oil is discharged from the constant discharge pump 28 through the discharge pipe 30 as indicated by arrow 35. On the other hand, since the pressurized oil is sucked from the suction pipe 31 of the variable discharge pump 29 as shown by the arrow 36,
When the amount of the pressurized oil discharged to the discharge pipe 30 and the amount of the pressurized oil sucked to the suction pipe 31 are equal, the ram 7a of the hydraulic pressure reduction cylinder 7 maintains the current position. Next, when the gap between the rolling rollers 20 and 20a becomes wider than the set value, this is detected and the output thereof is set to the variable discharge pump 2.
The variable discharge pump 29
Is reduced and is sent to the hydraulic pressure reduction cylinder 7 by the difference in the flow rate of the pressurized oil, and the gap between the rolling rolls 20 and 20a is adjusted to be small.

Contrary to the above, when the gap between the rolling rolls 20 and 20a is increased, if the suction amount of the variable discharge pump 29 is made larger than the discharge amount of the constant discharge pump 28,
Since the pressure oil in the hydraulic pressure reduction cylinder 7 (by the controller) is reduced by the difference between the suction amount and the discharge amount, the reduction force is reduced and the roll gap is increased accordingly.

As described above, the variable discharge pump 29 can be controlled by calculating the difference between the measured value of the hydraulic pressure reduction roll gap and the set value, and the hydraulic pressure reduction roll gap can be finely adjusted.

[0028]

[Embodiment 5] An embodiment of hydraulic pressure adjustment will be described with reference to FIG.

Rolls 20, 20 are placed in the rolling stand 8.
A is installed, and the hydraulic pressure reduction cylinder 7 is interposed between the bearing 6 of the rolling roll 20 and the rolling stand 8.

On the other hand, the pressurized oil is fed after being adjusted by a constant discharge pump 28 driven by a constant speed motor 37 and a variable discharge pump 29 driven by a variable motor 38.

That is, the discharge pipe 30 of the constant discharge pump 28.
The suction pipe 31 of the variable discharge pump 29 is connected to the. This point is the same as the fourth embodiment.

In the above, when the roll gap between the rolling rolls 20 and 20a becomes smaller than the set value, the output of the gap measuring device is input to the controller 41, the rotation of the variable motor 38 is accelerated, and the variable discharge pump. Increase the inhaled dose of 29. In this case, since the pressurized oil in the hydraulic pressure reduction cylinder 7 is drawn out through the discharge pipe 30 as indicated by the arrow 39,
The force applied to the rolling roll 20 is reduced, the rolling roll 20 is moved up by that amount, and the rolling gap is adjusted. Contrary to the above, when the gap between the rolling rolls 20 and 20a is larger than the set value, the set value is input to the controller 41 and the variable motor 38
To turn around. In this case, since the suction amount of the variable discharge pump 29 is smaller than the discharge amount of the constant discharge pump 28, the difference amount is sent to the hydraulic pressure reduction cylinder 7 as indicated by the arrow 40, and the rolling roll 20 is lowered to perform rolling. The gap will be adjusted.

As described above, it is possible to control the variable discharge pump by the variable motor, control the supply of the pressurized oil to the hydraulic pressure reduction cylinder 7, and properly maintain the gap between the rolling rolls 20 and 20a.

[0034]

Sixth Embodiment An embodiment relating to strain measurement of the rolling stand 8 will be described with reference to FIG.

In the cast steel rolling stand 8, the stand frames 8a and 8b usually have different elastic strains. The reason is that, when casting is performed with the stand frame 8b of the rolling stand 8 facing down, the stand frame 8b naturally has a higher metal density and a smaller elastic strain. Therefore, for the stand frame 8b, the magnetic position detector 9 is installed between the bearing of the rolling roll 20 and the upper part of the stand frame 8b (that is, the total strain is measured). Next, stand frame 8
With respect to a, the magnetic position detector 9 is fixed to the bearing of the rolling roll 20, and measurement is performed with the measuring rod 43 which is raised to the middle of the rolling stand 8. By doing so, for the stand frame 8b, the elastic strain of the entire length enters the measured value, and for the stand frame 8a, the elastic strain from the measurement frame 43 to the upper part of the stand (hydraulic pressure reduction cylinder abutting portion). You will be in the measurement. However, since the elastic strain amount for a fixed length of the stand frame is constant, the stand frame 8
If the elastic properties of a and 8b are measured, the stand frame 8
It is possible to equalize the elastic strain amounts at the measurement sites in a and 8b. Reference numeral 44 in the figure denotes a micro adjustment screw.

The micro adjusting screw is used when the operator actually sees the flow of the rolled product plate during rolling and finely adjusts the thickness of the product plate in the width direction (direction perpendicular to the rolling direction) from the light reflection. . For example, the micro adjusting screw moves up and down by 1/100 mm in one rotation. The roll gap can be adjusted by 1 micron at a time by pressing a button on the keyboard as an input to the controller. Depending on the type of rolling, the adjustment by the micro adjustment screw (analog operation) may be more advantageous than the case by the button operation (digital operation). For example, it is used for a material having a large elastic deformation range (stainless steel plate, etc.), but it depends on the sensitivity of the operator.

[0037]

The present invention sets the rolling roll gap,
There is an effect that the difference between the set value and the measured value is compared and calculated, and the amount of oil given to the hydraulic pressure reduction cylinder can be controlled with high accuracy by the control of two oil amount control valves interposed in the oil supply system.
This has the effect of enabling continuous production of rolled products with good thickness accuracy. Further, since the elastic strain amount of the stand frame can be measured and controlled by including it in the calculated value, there is an effect that the thickness accuracy can be maintained at a higher accuracy (3/1000 mm or more).

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention.

FIG. 2 is a block diagram of another embodiment of the present invention.

FIG. 3 is a block diagram of an embodiment in which a schematic diagram of the apparatus is also added.

FIG. 4 is a block diagram of an embodiment in which a variable discharge pump is used with a schematic drawing of the device added.

FIG. 5 is a block diagram of an embodiment in which a variable motor is also used by adding a schematic drawing of the device.

FIG. 6 is a side view of a rolling mill in which a part of the rolling mill is similarly shown, showing an example of installation of a magnetic position detector.

[Explanation of symbols]

1 setting device 2 hydraulic pump 3 oil tank 6 bearings 7 Hydraulic pressure reduction cylinder 8 rolling stand 9 Magnetic position detector 10 Comparison calculator 11, 12 Oil quantity control valve 13, 14 Stepping motor 19 bearings 20, 20a Rolling roll 22 Reverse pressure cylinder 23 Rolled material 24 Thickness setting device 25 Thickness measuring instrument 26 Comparator 27 motor 28 Constant discharge pump 29 Variable discharge pump 37 constant speed motor 38 Variable motor

Claims (10)

[Claims] 1. A method of setting a roll gap of a rolling roll, calculating a deviation between the set value and a measured value of the roll gap, and controlling the roll gap by the output, to a hydraulic pressure reduction cylinder of the rolling roll. A hydraulic pressure reduction control method for a rolling mill, characterized in that pressurizing oil having a positive and negative flow rate difference controlled by the output of the calculation is applied. 2. The hydraulic pressure reduction control method for a rolling mill according to claim 1, wherein the pressurized oil having a positive and negative flow rate difference is generated by applying pressurized oil in opposite flow directions to a hydraulic pressure reduction cylinder. 3. A roll gap of a rolling roll is set, and the deviation between this set value and the measured value of the roll gap and the deviation between the set value of the thickness of the rolled material immediately after rolling and the measured value are calculated, and the difference is calculated. In a method of controlling a roll gap by an output, a hydraulic pressure reduction control of a rolling mill is characterized in that a pressurized oil having a positive and negative flow rate difference controlled by the output of the calculation is applied to a hydraulic pressure reduction cylinder of a rolling roll. Method. 4. Roll roll gap setting means for the rolls,
The comparison calculation means of both means is connected to the measurement means, and two flow rate control means having opposite flow directions controlled by the output of the comparison calculation means are connected in parallel to the oil supply system of the hydraulic pressure reduction cylinder of the rolling roll. A hydraulic pressure reduction control device for a rolling mill, which is characterized by being inserted through. 5. The hydraulic pressure control device for a rolling mill according to claim 4, wherein the roll gap measuring means is a magnetic position detector. 6. The roll gap measuring means is a magnetic position detector, and the measuring rod of the magnetic position detector has a measuring rod between a bearing of an upper rolling roller and an upper stand, and an intermediate part and an upper part of a stand lifted from a machine stand. The hydraulic pressure reducing device for a rolling mill according to claim 4, wherein the pressure is provided between the bearings of the rolling rollers. 7. The hydraulic pressure reducing device for a rolling mill according to claim 5, wherein the tip of the measuring rod of the magnetic position detector is opposed to the end of the micro adjusting screw. 8. The hydraulic pressure control device for a rolling mill according to claim 4, wherein the flow rate adjusting means is a flow rate adjusting valve. 9. The flow rate adjusting means connects a suction side of the variable discharge pump and a supply / discharge pipe of a hydraulic pressure reduction cylinder to a discharge side of the constant discharge pump, and a discharge amount control circuit of the variable discharge pump. 5. The hydraulic pressure reduction control device for a rolling mill according to claim 4, further comprising an output for calculating a deviation between the set value of the roll gap and the measured value. 10. The flow rate adjusting means includes a constant rotation motor and a constant discharge amount pump, and a variable rotation motor and a variable discharge amount pump in parallel, and a discharge side of the constant discharge amount pump and a suction side of the variable discharge amount pump. The hydraulic pressure reduction control device for a rolling mill according to claim 4, wherein the hydraulic pressure reduction control device is connected to a cylinder, and a suction side of the constant discharge pump and a discharge side of the variable discharge pump are connected to an oil tank.