JPS6024727B2 - Hydraulic reduction control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hydraulic reduction control system for controlling the reduction direction using hydraulic pressure in hot strip mills, plate mills, tandem cold mills, and the like.

An example of this type of device was the one shown in Figure 1.

In this figure, reference numeral 1 denotes a hydraulic rolling device that determines the roll gap of the rolling mill, that is, the lower layer to be rolled, and is equipped with a rolling cylinder inside. 2 is a servo valve that drives the hydraulic pressure reduction device 1;
3 is a position detector for detecting the lower layer, 4 is a hydraulic lower layer control gain device, 5 is a lower layer integrator, 6 is a manual lowering operation device for the operator, and 7 is an external lowering counterfeit setting device (for example, a computer, digital 8 is an automatic pressure lower layer controller.

In general, a hydraulic reduction control system provides a faster response than a screw reduction control system using an electric motor, so it is used for highly accurate material thickness control.

In this case, if an integrator is not used for the reference value, it will act as a step response due to the high speed and overshoot will occur.
As a result, the settling time of the lower layer increases, and the accuracy of the lower calendar magnetic field deteriorates, which also has an adverse effect on the mechanical system.
In order to solve this problem and obtain an optimal response, a pressure reduction path integrator 5 is provided at the reference value, and the hydraulic pressure reduction control system is configured so that the feedback system follows. Next, the operation will be explained. The hydraulic rolling device 1 moves a rolling cylinder therein up and down to determine the roll gap of the rolling mill, that is, the rolling position, and rolls the material to be rolled to a predetermined thickness.
This reduction cylinder is driven and controlled by a servo valve 2. Further, the lower rolling layer is detected by the position detector 3, and the hydraulic lowering control system outputs a control signal to the servo valve 2 so that the detected lower rolling path becomes a predetermined lower rolling layer as a rolling position feedback value SPBK. do. The reduction value integrator 5 is necessary for manual reduction setting by an operator or automatic reduction position setting by external setting, and outputs a reduction layer reference value SREF*. In general, a characteristic of the hydraulic pressure reduction control system is that it must be controlled to always maintain the lower layer in its normal position. This is usually called localization control. Localization control is △S=SREF*-SFBK
...[1] However, △S: Lower layer deviation SREF
*: Pressure lower layer reference value SPBK: Pressure lower layer feedback value, control is performed so that ΔS=0.

This loop must always work regardless of whether the operation mode is manual or automatic.

Now, the following two methods are usually considered as methods for setting the lower layer.

One method is to set the pressure lower layer manually by an operator.

In this case, it is called manual mode, and while the pressure lower direct rise command or lower pressure command is issued by the operator, the pressure lower direct reference value SREF* is integrated by the pressure lower layer integrator 5, and the servo valve 2 is driven. The stereotactic control loop sets the pressure to an arbitrary lower layer. The other method is to set the pressure calendar using an external pressure setting device 7. In this case, it is called an automatic mode, and is set to an arbitrary lower layer using setting data from a host computer or a digital switch, for example. Here, the operation of the automatic pressure lower layer controller 8 will be explained. now,
Assume that the external pressure lower layer setter 7 gives the pressure lower layer setting value SREF and starts automatic pressure lower calendar setting (this state is
(denoted as CON), and the following equation is calculated. ERR=SRE
F-SFBK ......'2' However, ERR: Pressure lower counterfeit setting deviation SREF: Pressure lower pupil setting value SFBx: Pressure lower feedback value Pressure lower layer setting deviation ERR has both positive and negative polarities. have, ER
When R>0, it indicates a command to raise the pressure position, and when ERR<0, it indicates a command to lower the pressure position.

According to the polarity of the rolling lower layer setting deviation ERR determined by the formula '2', the automatic rolling lower layer controller 8 outputs a rolling lower direct rise command or lowering command, and the rolling lower layer integrator is output as in the manual mode. In step 5, the lower pupil reference value SREF* is integrated, the servo valve 2 is driven, and a predetermined lower pupil path is set by the localization control loop. The above operations are not executed until ERR = 0, but there is usually a zero error range and IER
RISZE ......'3' However, 5: Zero error - range Control is executed until ZE>0.

The timing at which the third equation holds true is called the APC zero error. The above operation is shown in FIG. That is, when APCON' is exceeded, the rolling lower layer reference value SREF* changes in an oblique manner toward the rolling lower direct setting value SREF. Along with this, the pressure reduction calendar feedback value SFBx follows, but due to the delay in the hydraulic pressure reduction control system, it changes obliquely with a slight delay. Then, the pressure lower layer reference value SRBF*' changes until the pressure lower layer setting deviation ERR enters the zero error range, and stops at the time of the APC zero error. Note that the input to the rolling lower layer integrator 5 is the angle of the slope, that is, the rolling speed, and not only the polarity of the position setting deviation ERR,
The reduction calendar integrator 5 is constructed so that the reduction speed can be varied according to its absolute value. Since the conventional hydraulic pressure reduction control device is configured as described above, it has the following drawbacks because it ignores the delay in the hydraulic pressure system.

In other words, if the zero error range is made smaller in order to improve the clarity of the automatic pressure lower layer setting, when the zero error is reached due to the delay in the system, as shown in Figure 3, the pressure lower layer reference value SR will be reduced.
EF* may already exceed the pressure lower layer set value SR8F. Then, the automatic lowering position setting is assumed to have been completed when the lower rolling layer feedback value SFBK has entered the zero error range, and since the localization control loop is always active, the lower rolling layer feedback value SF8x is the lower rolling layer reference value S.
The operation continues until it follows REF*, and when the zero error range of the pressure lower layer set value SREF is finally exceeded, the setting accuracy deteriorates as a result of the balance. This invention was made in order to eliminate the drawbacks of the conventional ones as mentioned above.
It is an object of the present invention to provide a hydraulic pressure reduction control device that can quickly set the automatic pressure lower layer and improve the setting accuracy.

An embodiment of the present invention will be described below with reference to FIG. In FIG. 4, reference numeral 9 denotes a pressure lower layer integrator according to the present invention;
0 is also an automatic pressure lower layer controller.

Note that numerals 1 to 4, 6, and 7 are the same as those in the conventional example shown in FIG. Next, this operation will be explained. The lower pressure layer integrator 9 and the automatic lower pressure layer integrator 10 operate in the same manner as those of the conventional ones, but they perform different operations when the zero error timing occurs.

That is, as shown in Fig. 5, when APC○N is performed, the lower pressure layer reference value SREP* changes in an annoying manner toward the lower pressure layer set value SREF, and after getting used to this, the lower pressure layer feedback value SFBK changes. It follows in an inclined manner, but when the pressure lower pupil setting deviation ERP enters the zero error range, it becomes 1, SRE
F*=SREF...{The output of the lower layer integrator 9 is adjusted to the lower layer set value SRE so that it becomes 41.
Preset to F itself.

Therefore, even if the localization control loop operates after the zero error is completed, the lower pressure layer feedback value SFBK will be equal to the lower pressure layer set value SR.
It works to match the EF and provides the correct pressure sublayer setting. In addition, although the above embodiment shows the case of automatic pressure lower calendar setting in a hydraulic pressure lowering control system, the present invention is not limited to this, but generally applies to devices that require automatic position setting for a system with a stereotaxic control loop. A similar effect is achieved for .

As explained above, according to the present invention, the automatic reduction layer is configured to be the setting pressure lower layer itself in consideration of the delay in the hydraulic reduction system, so that the reduction lower layer can be set quickly and with high setting accuracy. It has the effect of obtaining something.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a conventional hydraulic pressure reduction control device, FIGS. 2 and 3 are diagrams showing the operation of a conventional automatic pressure lower layer setting, and FIG. 4 is a block diagram showing an embodiment of the present invention. FIG. 5 is a diagram for explaining the operation of FIG. 4. In the figure, 1 is the hydraulic pressure lower side calendar. 2 is a servo valve, 3 is a position detector, 4 is a hydraulic pressure reduction gain device, 6 is a manual pressure reduction operation device, 7 is an external pressure lower layer setting device, 9 is a pressure lower layer integrator, 10 is an automatic pressure reduction layer controller It is. Note that the same reference numerals in the figures indicate the same or corresponding parts. Fig. 1 Fig. 2 Fig. 3 Fig. Mu Fig. Chicken Fig. 5

Claims (1)

[Claims] 1. A hydraulic pressure-down device that determines a pressure-down position using hydraulic pressure, a servo valve that drives this hydraulic pressure-down device, a position detector that detects the pressure-down position, a pressure-down position integrator that outputs a pressure-down position reference value, a pressure-down position reference value, and a pressure-down position integrator that outputs a pressure-down position reference value. A positioning control system that controls the position so that there is no difference between the position value and the position value detected by the position detector, a manual position control system that allows the position integrator to manually set the position position, and an external position position set value and the position detection. In the hydraulic pressure-down control device, the automatic pressure-down position controller is equipped with an automatic pressure-down position controller that outputs a difference between the pressure-down position value detected by the machine and causes the pressure-down position integrator to automatically set the pressure-down position. A hydraulic pressure reduction control device comprising a control mechanism that sets the pressure reduction position reference value of the pressure reduction position integrator as the external pressure reduction position set value at the time when the pressure reduction position setting of the pressure reduction position integrator is completed. .