KR20020048203A - Apparatus for detecting and controlling flatness in levelling machine - Google Patents

Abstract

PURPOSE: An apparatus for detecting and controlling flatness in a leveling machine is provided to remove maloperation the leveling machine due to maloperation of the detectors by installing position detectors at the inner and outer parts of a cylinder installed at the leveling machine, thereby detecting accurate position values. CONSTITUTION: In an apparatus for detecting and controlling flatness in a leveling machine adjusting a roll gap through two or more hydraulic cylinders(3), the apparatus for detecting and controlling flatness in the leveling machine comprises two or more of first position detection parts(21) which are mounted on inner parts of each hydraulic cylinders(3) inside the leveling machine so as to measure moving distances of the cylinders corresponding to positions of rolls; two or more of second position detection parts(22) which are mounted on outer parts of the hydraulic cylinders by being connected to rods of the hydraulic cylinders(3) so as to measure moving distances of the hydraulic cylinders; a comparison switching control part(25) selectively outputting a value having a small deviation by comparing measured values of each of the first position detection parts(21) and the second position detection parts(22) mounted on the same hydraulic cylinder with a standard value; and a control part(26) outputting the adjusted control output values by up/down adjusting control output values so that an error between measured values impressed from the comparison switching control part(25) and the standard value is not deviated from the set range.

Description

Flatness detection and control device in calibrator {APPARATUS FOR DETECTING AND CONTROLLING FLATNESS IN LEVELLING MACHINE}

The present invention relates to a hot calibration apparatus for correcting the flatness of the thick plate is installed in the rear end of the rolling mill, and more particularly, by installing a position detector on the inside and outside of the cylinder installed in the calibrator to detect a more accurate position value therefrom detector malfunction The present invention relates to a flatness detection and control device in a calibrator that eliminates malfunction of the calibrator.

The hot-calibrator corrects the unevenness of the top, bottom, middle and side surfaces of the raw materials (300 ~ 1100 ℃) generated during the rolling after rolling in the rolling mill. Device.

In general, a material such as a slab, such as a slab, is uniformly heated in a heating furnace and cracked at 1180 to 1250 ° C., followed by rough rolling and finishing rolling. It is calibrated in a hot calibrator.

The hot-calibration device also employs a quadruple with a strong back-up roll to cope with high speed and high quality, and relatively small roll diameter and roll pitch so that a straightening effect can be obtained as a straightening device for thin materials and thick materials.

FIG. 1 shows a control device of a conventional calibrator. In the related art, a signal detected by the position detectors PE1 to PE4 installed inside four cylinders 3 up and down the backup roll unit 2 of the calibrator 1 is a signal. Input to the conversion unit 11, the signal conversion unit 11 converts the signals output from the position detectors PE1 to PE4 to the measured value through a detector to apply to the calculation unit 12, the calculation unit ( 12) compares each measured value with each reference value and if the control set value SP1 to SP4 is larger than the measured value PV1 to PV4, the current control output values MV1 to MV4 are converted to the unit output values ΔMV1 to ΔMV4. On the contrary, if the set values SP1 to SP4 are smaller than the measured values PV1 to PV4, the current control output values MV1 to MV4 are increased by the unit output values ΔMV1 to ΔMV4, and the signal converter 11 ) The signal converting unit 11 amplifies the output value input from the calculating unit 12 through an amplifier to a predetermined level range (DC 1 to 5V) so as to increase the hydraulic pressure of the four cylinders 3 which up-down the backup roll unit 2. It is applied to the hydraulic control unit 10 to control.

The hydraulic control unit 10 operates the torque motors (TM1 ~ TM4) according to the output value to adjust the amount of oil supplied by the pump (8), the cylinder (3) is raised / lowered to correct The roll gap of the roll 1 is adjusted. When the raw material 13 is charged between the straightening rolls 1, the straightening rolls 1 absorb the straightening reaction force, and each cylinder 3 continuously operates to form a hydraulic circuit.

However, the conventional calibrator as described above moves the pilot cover (pilot covet) in which the control signals applied to the torque motors TM1 to TM4 are built into the motor, and operates the servo piston accordingly. Foreign substances are generated and adhered to the tank inner wall, pipe inner wall, cooler tube, etc., and by closing the filter, the cross-sectional area of the pipe is reduced, and the hydraulic pressure distributed to each cylinder pipe is different. The area is divided into entry drive side, entry work side, delhi drive side, and delhi walk side to detect and control the position. However, the position detector mounted inside the cylinder is between the screw 4 and the spherical plate. When grease is injected, grease and foreign substances enter into the inner hole and malfunction, so accurate measurement value is not output. There is a time.

In this case, cylinder abnormal high pressure or abnormal deviation occurs due to abnormal operation of the cylinder. In the past, only periodic inspections have been carried out, but since it is not possible to know the exact state from this, it is impossible to diagnose in advance. Malfunction of the detector caused the production line to stop.

Therefore, the present invention has been proposed to solve the above-mentioned conventional problems, and an object thereof is to simultaneously install a position detecting sensor inside and outside of a cylinder installed for each region in the calibrator, so that one of the outputs of the two sensors is measured. It is to provide a flatness detection and control device in the calibrator to solve the problems caused by the position detection failure and to maximize the flatness control efficiency of the material to eliminate the thickness difference of the material to achieve uniform control.

1 is a block diagram showing a conventional flatness detection and control device.

2 is a block diagram showing a flatness detection and control apparatus according to the present invention.

Figure 3 is a cross-sectional view showing a position detector installed on the outside of the cylinder in accordance with the present invention.

4 is a blur configuration diagram showing the configuration of the comparison switching control unit included in the apparatus according to the present invention.

5 is a waveform state diagram of a controller by the apparatus of the present invention.

* Description of the symbols for the main parts of the drawings *

21, 22: first position detection unit

23,24: first and second signal conversion unit

25; Comparative Switching Control Unit

26: control unit

27: automatic / manual switching part

28: amplification unit

As a construction means for achieving the above object of the present invention, the present invention is a flatness detection and control device in the calibrator for adjusting the roll gap through two or more hydraulic cylinders,

Two or more first position detection units mounted inside each of the hydraulic cylinders in the straightener to measure a moving distance of the cylinder corresponding to the roll position;

Two or more second position detection parts fixedly connected to a rod of the hydraulic cylinder and mounted outside the hydraulic cylinder to measure a moving distance of the hydraulic cylinder;

A comparison switching control unit for comparing the measured values of each of the first position detection unit and the second position detection unit mounted on the same hydraulic cylinder with a reference value and selecting and outputting the smaller one of the deviations; And

And a control unit for outputting the control output value by adjusting the up / down so that the error between the measured value and the reference value applied from the comparison switching controller does not deviate from the set range.

In addition, in the apparatus, the second position detection unit

After the fixing lever is installed on the rod of the hydraulic cylinder so as to be perpendicular to the rod, the fixing lever is fixed with a bolt, and a guide that provides a straight up / down path outside the main body of the hydraulic cylinder is fixedly installed and moved up and down on the guide. A guide shaft is provided to connect the upper part of the guide shaft to the fixing lever, a sensor housing is attached to the guide, a magnetic scale is installed inside the sensor housing, and the upper part of the magnet scale is mounted on the guide shaft. It is fixed to the connected fixed lever, characterized in that made by installing a bellows between the fixed lever and the sensor housing in order to prevent foreign matter penetration from the outside.

Hereinafter, a flatness detection and control device in a calibrator according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 2 is a block diagram showing a flatness detection and control device according to the present invention, each of which is mounted inside four hydraulic cylinders 3 in the calibrator and measures each moving distance of a cylinder corresponding to a roll position. A second position detecting unit 22 connected to the position detecting unit 21, a rod of four hydraulic cylinders 3 in the calibrator, and detecting a moving distance of the hydraulic cylinder 3, and the first position detecting unit 21; And first and second signal converters 23 and 24 for converting the output signals of each of the second and second position detectors 22 into measured values PV, and output values of the first and second signal converters 23 and 24. Is compared with the control output value MV applied to the calibrator and outputs the smaller deviation, and the control output value according to the difference between the measured value and the reference value applied from the comparison switching control unit 25. Control unit 26 for outputting up and down adjustments, and an operator is applied with an automatic setting value of the control unit 26. Auto / manual switching unit 27 for selecting lock or manual setting value, and control output value (MV) output through the auto / manual switching unit 27 to the operation control range (1-5V) of the motor. It consists of an amplifier unit 28 for adjusting and outputting.

FIG. 3 is a structural diagram showing the actual configuration of the second position detecting unit 22 described with reference to FIG. 2. The fixing lever 33 is installed on the rod 32 of the hydraulic cylinder 3 so as to be perpendicular to the rod 32. After that, it is fixed with a bolt, and fixed to the guide 34 for providing a straight up / down path outside the main body 31 of the hydraulic cylinder (3), the guide to move up and down on the guide 34 The shaft 35 is provided, and the upper portion of the guide shaft 35 is connected to the fixing lever 33, and the sensor housing 36 is attached to the guide 34, and inside the sensor housing 36. The magnetic scale 36 is installed, and the upper portion of the magnet scale 360 is fixed to the fixing lever 33 to which the guide shaft 35 is connected, and the fixing lever 33 and the sensor to prevent foreign substances from penetrating from the outside. A bellows 38 is installed between the housings 36.

FIG. 4 is a block diagram showing the configuration of the comparison switching control unit 25 described with reference to FIG. 2, and compares the measured value output from the first position detecting unit 21 with the control output value and outputs the difference. A first comparator 41, a second comparator 42 for comparing the measured value output from the second position detector 22 with the control output value and outputting the difference, and the first and second comparator 41 And a selection unit 43 for comparing two deviation values outputted from (42) and selecting the smaller one, and an output unit 44 for outputting the deviation selected by the selection unit 43.

In FIG. 2, the first and third position detectors 21 and 22 are magnetic scales mounted inside and outside the four hydraulic cylinders 3 installed in the calibrator. Generate a pulse value.

Among them, the operation of the second position detection unit 22 is as follows.

The control output value output from the control unit 26 is level-adjusted by the amplifying unit 28 via the automatic / manual switching unit 27 selected by the automatic stage, and is then continuously transmitted to the torque motor of the hydraulic control unit 10. In addition, by moving the pilot cover embedded in the motor and operating the servo piston accordingly, the hydraulic pressure is transmitted to the hydraulic cylinder (3) to move the cylinder rod. At this time, the fixed lever 33 attached to the cylinder rod 32 is operated up and down, together with the guide shaft 35 assembled with the cylinder body 31, the magnetic scale 37 of the second position detection unit 22 is upward. Move downward to detect travel distance.

In the above, the role of the guide shaft 34 is to prevent the detection error caused by the deformation of the lever 33 to which the magnetic scale 37 is fixed, to prevent bending of the fixing lever 33 by assembling by precise tolerances. do.

In addition, after installing the fixed lever 33 for the magnetic scale attached to the rod of the hydraulic cylinder (3) and the guide shaft 35 assembled with the cylinder body 31, and installed accordingly, the upper and lower, left and right level fixing sensor The magnetic scale 37 is installed inside the housing 36 and the sensor housing 36, and a bellows 38 is installed to prevent foreign matter from penetrating from the outside to constitute the second position detecting unit 22.

Each detection signal output from the first and second position detectors 21 and 22 is input to the first and second signal converters 23 and 24 and amplified to a predetermined level, respectively, and converted into an up / down pulse. do. The signals output from the first and second signal converters 23 and 24 are input to the comparison conversion controller 25.

The comparison conversion control unit 25 compares the two input signals with the control output applied from the amplification unit 28 to the hydraulic conversion control unit 10, and outputs the smaller deviation to the control unit 26. . The control unit 26 outputs the control output value up / down so that an error between the input measurement value and the control output value is within an allowable range (eg, ± 1 mm), and the control output value output from the control unit 26 is The amplification part 28 is input to the amplification part 28 via the automatic / manual switching part 27 which is automatically set, and the amplification part 28 gain-controls into the hydraulic cylinder control range (DC 1-5V), and the hydraulic pressure control part 10 is carried out. Will output

Thus, as described above, the signal is continuously transmitted to the torque motor in the hydraulic control unit 10, the pilot cover (hard plate) connected to the motor shaft opens and closes the rotary vane hole (rotary vane hole) of each area A flow path is formed in the hydraulic cylinder (3).

FIG. 5 is a circuit diagram showing waveforms in the first and second position detection units 21 and 22 according to the present invention, in which magnetic heads are read on magnetic scales S and N like the tape record. It is used for.

The playhead of the tape record can be considered to be a coiled U-shaped iron core (playhead) coil. The magnetic flux on the scale enters the iron core. At this time, when the scale moves, the intensity of the magnetic flux flowing in the iron core changes, which causes an induced voltage in the coil. Since the intensity of the induced voltage corresponds to the intensity of the magnetic flux flowing in the iron core, it becomes a sine wave as shown in FIG. 5A. Thus, the playhead can pick up the sine wave electrical signal. On the contrary, when the scale is stopped, the intensity of the magnetic flux flowing in the iron core does not change, and no induced voltage occurs in the coil.

FIG. 5B shows the DC balance waveform before adjustment, and FIG. 5C shows the DC balance waveform after adjustment.

As described above, the fault diagnosis can be performed only through resistance measurement, oscilloscope measurement, or analysis check, and the detection position value is possible only after connecting the control system. In the calibrator provided with the position control device for flatness control, it is provided with the position detector which performs the same operation | movement outside the cylinder, and selects the one with less deviation from the control output among the output values of two position detectors, and uses it for control, It is possible to improve the degree of control, to stabilize the control system, and to minimize the influence on the facility management, production, and quality of the entire calibration facility, and to prevent the occurrence of production pause due to malfunction of the position detector in advance. There is.

Claims (3)

A flatness detection and control device in a calibrator that adjusts a roll gap through two or more hydraulic cylinders, Two or more first position detection units mounted inside each of the hydraulic cylinders in the straightener to measure a moving distance of the cylinder corresponding to the roll position; Two or more second position detection parts fixedly connected to a rod of the hydraulic cylinder and mounted outside the hydraulic cylinder to measure a moving distance of the hydraulic cylinder; A comparison switching control unit for comparing the measured values of each of the first position detection unit and the second position detection unit mounted on the same hydraulic cylinder with a reference value and selecting and outputting the smaller one of the deviations; And And a control unit which adjusts and outputs a control output value so that an error between the measured value and the reference value applied from the comparison switching control unit does not deviate from a set range. The method of claim 1, wherein the second position detection unit After the fixing lever 33 is installed on the rod 32 of the hydraulic cylinder 3 so as to be perpendicular to the rod 32, the fixing lever 33 is fixed with a bolt and the straight line rises outside the main body 31 of the hydraulic cylinder 3. And a guide 34 providing a downhill path, and having a guide shaft 35 to move up and down on the guide 34, and having an upper portion of the guide shaft 35 at the fixing lever 33. The sensor housing 36 is attached to the guide 34, the magnetic scale 36 is installed inside the sensor housing 36, and the upper portion of the magnet scale 360 is connected to the guide shaft 35. Flatness in the calibrator, characterized in that the bellows 38 is installed between the fixing lever 33 and the sensor housing 36 to be fixed to the connected fixing lever 33, to prevent foreign substances from penetrating from the outside. Detection and control devices. The method of claim 1, wherein the control device Flatness in the calibrator further comprises an automatic / manual switching part selectable to apply the control value output from the control unit to the hydraulic cylinder hydraulic regulator or to apply a manual setting value set by the operator to the hydraulic regulator of the hydraulic cylinder. Detection and control devices.