JPS6319242B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rolling control method for changing the running plate thickness of a hot rolled strip.

In recent years, hot tandem rolling mills have been able to automatically adjust the thickness of the finished product with high precision without reducing the rolling speed at all.
There is a rapidly increasing need for strip thickness changing rolling, which automatically rolls two or more consecutive products from a book strip to improve yield, fuel consumption, and reduce lot surplus material. .

In order to satisfy the above-mentioned needs, the present invention provides smooth and accurate rolling before and after changing the running thickness of a strip in tandem rolling mills arranged in two or more tandem rolling mills. The purpose is to perform control.

In order to achieve the above object, in the present invention,
The rolling position and rolling force detected immediately after the tip of the hot-rolled strip is bitten under the roll bit of the upstream rolling mill during strip thickness change rolling are stored as the reference rolling position and rolling force. Using this rolling position and rolling force, calculate the standard value of the thickness of the strip at the exit side of the upstream rolling mill, and then calculate the standard value of the thickness of the strip at the exit side of the upstream rolling mill. The detected plate thickness at the exit side of the upstream rolling mill of the strip being rolled is calculated, and this plate thickness is compared with the above-mentioned standard value for the exit side thickness of the upstream rolling mill, and the deviation of the thickness at the exit side of the upstream rolling mill is calculated. In addition, the rolling position and rolling force detected immediately after the tip of the strip is bitten under the roll bit of the downstream rolling mill are stored as a standard rolling position and standard rolling force, and the stored rolling position and rolling force are The standard value of the exit side thickness of the strip on the downstream side rolling mill is calculated using this value, and from then on, the downstream side rolling mill of the strip being rolled is calculated based on the rolling position and rolling force detected for the strip being rolled on this downstream rolling mill. By calculating the detected outlet plate thickness and comparing this plate thickness with the outlet plate thickness standard value of the downstream rolling mill, the outlet plate thickness deviation of the downstream rolling mill is calculated, and the calculated upstream rolling Using the exit side thickness deviation of the machine and the exit side thickness deviation of the downstream rolling mill, the exit side thickness deviation signal of the upstream rolling mill is once stored for each unit length of the strip, and the corresponding portion of the strip is By taking out the stored exit plate thickness deviation signal at each timing of reaching the machine, it is used as an entry plate thickness deviation signal of the downstream rolling mill, and the input plate thickness deviation signal of the downstream rolling mill and the calculated downstream rolling mill are combined. The mass balance fluctuation of the strip being rolled between the upstream rolling mill and the downstream rolling mill is calculated by calculating the rolling reduction variation in the downstream rolling mill using the exit side plate thickness deviation signal and the mass balance. When changing the running thickness of the strip during rolling by driving and controlling the speed drive control device of the upstream rolling mill so as to return to the original stable state from fluctuations in After the running plate thickness is changed in the downstream rolling mill, before rolling starts, the rolling speed correction amount of the upstream rolling mill is calculated by the reduction rate fluctuation calculation in the downstream rolling mill, and then the rolling speed correction amount of the upstream rolling mill is calculated. At the start of rolling, the rolling speed correction amount of the upstream rolling mill is memorized, and at the same time, the standard values of the entry thickness deviation and exit thickness deviation in the upstream rolling mill are changed to the entry and exit thickness deviations at that time. By replacing it with the thickness and storing it, the inlet and outlet thickness deviations of the downstream rolling mill at that point are set to zero, and then after the running plate thickness change starts, the updated inlet and outlet thickness standards are used. The rolling reduction rate variation in the downstream rolling mill is calculated based on the thickness deviation from the plate thickness, and the rolling speed correction amount of the upstream rolling mill is calculated.The rolling speed correction amount is added to the previously memorized rolling speed correction amount, and this correction amount is used to perform upstream rolling. By driving and controlling the speed drive control device of the machine, the mass balance fluctuation between the rolling mills is corrected, and then rolling is started again when the downstream rolling mill receives a separately input rolling plate thickness change rolling end signal. The amount of speed correction is memorized, and the reference values for the entry and exit thicknesses are replaced and stored with the thicknesses at that time.For subsequent strips, the new entry and exit thickness standards are used for subsequent strips. The input and exit plate thickness deviations are calculated, and the speed drive control of the upstream rolling mill is performed using the sum of the rolling speed correction amount of the upstream rolling mill calculated based on these plate thickness deviations and the memorized rolling speed correction amount. Drive and control equipment.

Hereinafter, the present invention will be explained in detail with reference to the drawings. FIG. 1 shows the configuration of an apparatus for implementing the present invention.
In FIG. 1, numeral 1 denotes a strip that is rolled to change the thickness during running, and numeral 2a rolls the strip 1 in a rolling mill on the upstream side of the strip 1. 2b is a rolling mill downstream of the strip 1, which rolls the strip 1. Reference numeral 3a denotes a rolling position detector which detects the roll gap under the roll bite of the upstream rolling mill 2a by converting it into an electric signal when the strip 1 is being rolled. Reference numeral 3b denotes a rolling position detector which detects the roll gap under the roll bite of the downstream rolling mill 2b by converting it into an electric signal when the strip 1 is being rolled. A rolling force detector 4a detects the rolling force of the upstream rolling mill 2a by converting it into an electric signal when the strip 1 is being rolled.
4b is a rolling force detector which converts the rolling force of the downstream rolling mill 2b into an electric signal and detects it when the strip 1 is being rolled. Reference numeral 5a denotes an exit side plate thickness deviation calculation device, which calculates the strip 1 to be rolled based on the rolling force signal and the rolling position signal under the roll bite detected by the rolling position detector 3a and the rolling force detector 4a in the upstream rolling mill 2a. The outlet plate thickness deviation of the upstream rolling mill 2a is calculated. Reference numeral 5b denotes an exit side sheet thickness deviation calculating device, which calculates the strip 1 to be rolled based on the rolling force signal and rolling position signal under the roll bite detected by the rolling position detector 3b and rolling force detector 4b in the downstream rolling mill 2b. This is to calculate the exit side sheet thickness deviation at the downstream rolling mill 2b. Reference numeral 8 denotes an inlet thickness deviation calculation device of the downstream rolling mill 2b, which inputs an outlet thickness deviation signal of the upstream rolling mill 2a of the strip 1 to be rolled calculated by the outlet thickness deviation calculation device 5a. , has the function of causing the portion of the strip 1 under the roll bite of the upstream rolling mill 2a to reach under the roll bite of the downstream rolling mill 2b at a certain point in time. Reference numeral 6 denotes a reduction compensation device, which calculates the exit side plate thickness deviation calculated by the exit side plate thickness deviation calculation device 5a of the upstream side rolling mill 2a and the exit side plate thickness calculated by the exit side plate thickness deviation calculation device 5b of the downstream side rolling mill 2b. In response to the deviation, the output side plate thickness deviation signal from the output side plate thickness deviation calculation device 5a of the upstream rolling mill 2a is temporarily stored in the storage section for each unit length of the strip 1, and the corresponding portion of the strip 1 is transferred to the downstream side rolling mill. By taking out the stored exit side plate thickness deviation signal of the upstream rolling mill 2a at each timing when the roll bite of roll bit 2b is reached, it is used as an entry side plate thickness deviation signal of the downstream rolling mill 2b. The upstream rolling mill 2a and the downstream rolling mill 2b are calculated by calculating the rolling reduction variation in the downstream rolling mill 2b using the input plate thickness deviation signal of the downstream rolling mill 2b and the calculated exit plate thickness deviation signal. The rolling speed of the upstream rolling mill 2a is controlled by the speed drive control device 7 so as to calculate the fluctuation in the mass balance of the strip 1 being rolled between the rolling mills 1 and 2, and control the rolling speed of the upstream rolling mill 2a to return the mass balance fluctuation to the original stable state. Correct and control mass balance fluctuations. 7
is a speed drive control device which corrects and controls the rolling speed of the upstream rolling mill 2a based on a rolling speed correction amount signal output from the rolling reduction compensator 6. Reference numeral 9 denotes a running plate thickness changing rolling timing input device, which stores the rolling plate thickness changing rolling start signal and end signal for storing the rolling plate thickness changing output signal of the rolling plate thickness compensating device 6 and updating the standard plate thickness. It has the function of outputting to 6.

In the device configuration as described above, the rolling position and rolling force detected by the rolling position detector 3a and the rolling force detector 4a immediately after the tip of the strip 1 is bitten under the roll bit of the upstream rolling mill 2a are transmitted to the output side plate. It is input to the thickness deviation calculating device 5a and stored as a standard rolling position and a standard rolling force, and the standard value of the exit side plate thickness of the upstream rolling mill 2a of the strip 1 is calculated using the stored rolling position and rolling force. From then on, the strip 1 being rolled by the upstream rolling mill 2a is determined based on the rolling position and rolling force detected by the rolling position detector 3a and the rolling force detector 4a for the strip 1 being rolled by the upstream rolling mill 2a. By calculating the detected exit plate thickness of the upstream rolling mill 2a and comparing this plate thickness with the reference value of the exit plate thickness of the upstream rolling mill 2a, the exit plate thickness deviation at the upstream rolling mill 2a is calculated. Also, the tip of the strip 1 is connected to the downstream rolling mill 2b.
The rolling position and rolling force detected by the rolling position detector 3b and the rolling force detector 4b immediately after the roll bite is bitten under the roll bite are inputted to the output plate thickness deviation calculating device 5b and stored as the standard rolling position and standard rolling force. Using the memorized rolling position and rolling force, calculate the reference value of the exit side thickness of the strip 1 at the downstream rolling mill 2b, and then calculate the standard value for the strip 1 rolled at the upstream rolling mill 2a. Based on the rolling position and rolling force detected by the rolling position detector 3b and the rolling force detector 4b, the detected plate thickness at the outlet side of the downstream rolling mill 2b of the strip 1 being rolled is calculated, and this plate thickness and the downstream side plate thickness are calculated. By comparing the reference value of the outlet side plate thickness of the rolling mill 2b, the outlet side plate thickness deviation of the downstream rolling mill 2b is calculated. Using the output thickness deviation of the upstream rolling mill 2a calculated through these calculations, the output thickness deviation signal of the upstream rolling mill 2a is input to the input thickness deviation calculation device 8, and is calculated for each unit length of the strip 1. Once stored, the inlet thickness of the downstream rolling mill 2b is calculated by taking out the memorized outlet thickness deviation signal of the upstream rolling mill 2a every time the corresponding portion of the strip 1 reaches the downstream rolling mill 2b. Signal. Using this inlet plate thickness deviation signal of the downstream rolling mill 2b and the calculated outlet plate thickness deviation signal of the downstream rolling mill 2b, the reduction rate fluctuation in the downstream rolling mill 2b is calculated, and the rolling reduction rate fluctuation in the downstream rolling mill 2b is calculated. In the rolling reduction compensation device 6, which drives and controls the speed drive control device 7 of the upstream rolling mill 2a, so as to restore the mass balance fluctuation of the strip 1 being rolled between the downstream rolling mills 2b to the original stable state, When changing the running plate thickness of the strip 1 in the middle, after the tip of the strip 1 is bitten by the downstream rolling mill 2b, the running plate thickness changing rolling timing input device 9 in the downstream rolling mill 2b is input. Until the board thickness change rolling start signal is received, the rolling speed correction amount of the upstream rolling mill 2a is calculated by the reduction rate fluctuation calculation in the downstream rolling mill 2b. Next, as soon as the running plate thickness changing rolling start signal is received from the running plate thickness changing rolling timing input device 9 in the downstream rolling mill 2b, the output signal from the rolling reduction compensating device 6 is applied to the rolling process in the upstream rolling mill 2a. It is stored as the speed correction amount, and at the same time the upstream rolling mill 2
By replacing and storing the reference values of the entry side plate thickness deviation and exit side plate thickness deviation at that time with the entry side plate thickness and exit side plate thickness at that time, the updated new entry side plate of the downstream rolling mill 2b at that time is obtained. The thickness deviation and exit side plate thickness deviation are zero. Therefore, after the start of changing the thickness during running, the rolling reduction compensating device 6 calculates the rolling reduction rate fluctuation in the downstream rolling mill 2b based on the thickness deviation from the updated new entry side thickness standard and exit side thickness standard, and Calculate the rolling speed correction amount of the rolling mill 2a, add it to the previously stored rolling speed correction amount of the upstream rolling mill 2a, and use this rolling speed correction amount to control the speed drive control device 7 of the upstream rolling mill 2a.
drive and control. Similarly, when the downstream rolling mill 2b receives a running plate thickness change rolling completion signal from the running plate thickness changing rolling timing input device 9, it stores the rolling speed correction amount again, and changes the input side plate thickness and exit side plate thickness. The reference value is replaced with the plate thickness at that time and stored, and for subsequent strips 1, the entry and exit thickness deviations from the updated new entry and exit thickness standards are calculated, and these deviations are calculated. The speed drive control device 7 of the upstream rolling mill 2a uses the sum of the rolling speed correction amount of the upstream rolling mill 2a calculated based on the plate thickness deviation and the memorized rolling speed correction amount.
The compensation operation of the reduction compensating device 6 that drives and controls the compensator 6 is performed smoothly and accurately.

FIG. 2 specifically illustrates the operation of the reduction compensation output before and after performing rolling to change the plate thickness during running. In the figure, ΔV is the output signal of the pressure reduction compensator 6, and ΔV _p is the stored value signal of the output. Further, ΔV _c is the reduction compensation device 6 provided to the speed drive control device 7.
is the control signal. As soon as ΔV _p is stored at the timing of starting rolling for changing plate thickness during running (point A in the figure), ΔV becomes zero.

The same operation as described above occurs also at the end timing of the rolling plate thickness change rolling (point B in the figure), but the control signal ΔV _c to the speed drive control device 7 is continuously output.

If this reduction compensation device 6 stores or re-memorizes the reduction compensation output value before and after rolling to change plate thickness during running, and updates or re-updates the reference plate thickness, the reference value of the reduction compensation operation is set to the rolling value. This is the point at which the tip of the strip is bitten, and in the case of rolling with a change in plate thickness during running, the plate thickness and reduction rate will change significantly, and the amount of correction for mass flow fluctuations will be significantly large. Since the thickness deviation on the exit side is expressed by a first-order approximation equation, the accuracy of this approximation is significantly degraded due to the nonlinearity of the rolling conditions. Therefore, when rolling while changing the plate thickness, the accuracy of the reduction compensation operation is greatly reduced and smooth operation cannot be expected.

However, according to the present invention as described above, when performing strip thickness change rolling during running, the entrance side thickness deviation and exit side thickness deviation before and after the rolling can be kept constantly at small values, and highly accurate reduction compensation operation can be performed. This makes it possible to thread the rolled strip stably and accurately. Further, there is an effect that the plate thickness can be changed smoothly and accurately during rolling.

Note that the present invention can also be applied to a case where three or more tandem rolling mills are arranged side by side. For example, if there are a first, second, and third tandem rolling mill from the upstream side, first consider the mass balance between the first and second rolling mills, with the first rolling mill being the upstream rolling mill and the second rolling mill being the upstream rolling mill. The present invention is applied with the rolling mill as the downstream rolling mill, and regarding the mass balance between the second and third rolling mills, the second rolling mill is the upstream rolling mill and the third rolling mill is the downstream rolling mill. The present invention may be applied as a machine. Similarly, the present invention can also be applied to a case where four or more tandem rolling mills are lined up. That is, the above description of the present invention has been described for any two adjacent rolling mills, but the present invention can also be applied to three or more rolling mills as described above.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an apparatus for implementing the present invention, and FIG. 2 is a time chart showing the pressure compensation output before and after rolling to change the running plate thickness in implementing the present invention. 1...Strip whose plate thickness is changed during running, 2a...
...Upstream rolling mill, 2b...Downstream rolling mill, 3a,
3b... Rolling position detector, 4a, 4b... Rolling force detector, 5a, 5b... Output side plate thickness deviation calculation device,
6... Roll-down compensation device, 7... Speed drive control device,
8... Entrance plate thickness deviation calculating device, 9... Rolling timing input device for changing plate thickness during running.

Claims (1)

[Claims] 1. In a continuous hot rolling mill that changes the running thickness of the strip during hot rolling, the rolling position and rolling force detected immediately after the tip of the strip gets caught under the roll bit of the upstream rolling mill are used as the reference rolling. The position and standard rolling force are stored, and the memorized rolling position and rolling force are used to calculate the standard value of the thickness of the strip on the upstream rolling mill exit side, and the strip is subsequently rolled in this upstream rolling mill. Calculating the detected plate thickness on the upstream rolling mill exit side of the strip during rolling based on the detected rolling position and rolling force for the strip, and comparing this plate thickness with the above-mentioned upstream rolling machine exit side thickness reference value. The thickness deviation at the exit side of the upstream rolling mill is calculated, and the rolling position and rolling force detected immediately after the tip of the strip is bitten under the roll bit of the downstream rolling mill are used as the standard rolling position and standard rolling force. The memorized rolling position and rolling force are used to calculate the standard value of the strip thickness at the exit side of the downstream rolling mill. The downstream rolling mill exit side detection thickness of the strip being rolled is calculated based on the rolling position and rolling force, and by comparing this thickness with the downstream rolling mill exit side standard thickness reference value, the downstream rolling mill thickness is calculated. Calculate the exit plate thickness deviation, and use the calculated exit plate thickness deviation of the upstream rolling mill and downstream rolling mill to convert the output plate thickness deviation signal of the upstream rolling mill into the unit length of the strip. By storing the output side thickness deviation signal of the upstream rolling mill and retrieving the memorized exit side plate thickness deviation signal of the upstream rolling mill at each timing when the corresponding portion of the strip reaches the downstream rolling mill, the input side plate thickness deviation signal of the downstream rolling mill is obtained. Then, the rolling reduction rate of this rolling mill is calculated by calculating the rolling reduction rate fluctuation in the downstream rolling mill using the input plate thickness deviation signal of the downstream rolling mill and the calculated outlet plate thickness deviation signal of the downstream rolling mill. The fluctuation is detected, the fluctuation in the mass balance of the strip being rolled between the upstream rolling mill and the downstream rolling mill is calculated using this rolling reduction fluctuation, and this fluctuation in mass balance is returned to the original stable state. In reduction compensation, which corrects and controls mass balance fluctuations in the strip being rolled between the upstream and downstream rolling mills by driving and controlling the speed drive control device of the upstream rolling mill, When changing the strip thickness, after the tip of the strip is bitten by the downstream rolling mill, until the downstream rolling mill starts rolling to change the strip thickness, the upstream strip thickness is calculated based on the reduction rate fluctuation calculation in the downstream rolling mill. The rolling speed correction amount of the rolling mill is calculated, and then, at the start of rolling to change the running plate thickness in the downstream rolling mill, the rolling speed correction amount of the upstream rolling mill is stored, and at the same time, the entry side plate thickness in the upstream rolling mill is calculated. By replacing and storing the reference values of the deviation and exit side plate thickness deviation with the entry side plate thickness and exit side plate thickness at that time, the updated new entry side plate thickness deviation and exit side plate thickness deviation of the downstream rolling mill at that time can be obtained. is set to zero, and after the start of changing the running plate thickness, the reduction rate fluctuation in the downstream rolling mill is calculated based on the plate thickness deviation from the updated new entry-side reference plate thickness and exit-side reference plate thickness, and The rolling speed correction amount is calculated and added to the previously memorized rolling speed correction amount of the upstream rolling mill, and this rolling speed correction amount is used to drive and control the speed drive control device of the upstream rolling mill. When the rolling mill finishes changing the strip thickness during running, it stores the rolling speed correction amount again, replaces the reference values for the entrance and exit thicknesses with the sheet thicknesses at that point, stores them, and stores them for subsequent strips. is the rolling speed correction amount of the upstream rolling mill calculated by calculating the entrance and exit side plate thickness deviations from the updated new entry side plate thickness standard and exit side plate thickness standard, and the above-mentioned stored rolling speed. A strip thickness changing rolling control method, characterized in that rolling compensation is performed by driving and controlling a speed drive control device of an upstream rolling mill using the sum of the correction amount.