JPH06102211B2 - Plate thickness controller for continuous rolling mill - Google Patents

Description

Detailed Description of the Invention [Industrial applications]

The present invention relates to a plate thickness control device for a continuous rolling mill that constantly controls the plate thickness of the tail end of a rolled material passing between a plurality of stands.

[Prior art]

FIG. 3 is a block diagram showing a plate thickness control device for a conventional continuous rolling mill. In FIG. 3, reference numeral 1 denotes an automatic plate thickness control signal (hereinafter, referred to as a plate thickness control signal for controlling a plate thickness of a rolled material biting in front and rear stands). AGC ・ R
EF) generator, 2 is a tail end compensation value setting device for setting a tail end compensation value for correcting the plate thickness of the tail end portion when the tail end comes out of the front stand, and 3 is a computing unit Reference numeral 4 denotes a roll opening memory, and 5-a, 5-b, 5-c are relays (switching means) that are closed at respective timings described later. A pulse transmitter 6 detects the roll opening, and its output is input to the position detection counter 7. 8 is a subtracter that detects the difference between the value of REF and the output value of the position detection counter 7, and 9 is the deviation, that is, the operation of generating a signal to the control system that sets the roll opening by the output of the subtracter 8. , 10 is a digital-analog converter, 11 is a thyristor device for driving an electric motor, 12 is an electric motor for driving a roll reduction device, and 13 is a roll of a stand. FIG. 4 shows an outline of the continuous rolling mill. A plurality of stands F1 to F6 are arranged in parallel at intervals of l so that the rolled material 18 is conveyed in the direction of the arrow through the rolls of each stand. It is configured. Next, the operation will be described. In the continuous rolling mill as shown in FIG. 4, when the rolled material 18 is biting in the front and rear stands, the roll opening is controlled by the output signal from the AGC / REF generator 1 which controls the plate thickness to be constant. I do. At that time, relay 5-
c is closed. When the tail end of the rolled material 18 passes through the front stand, the tension between the next stands becomes zero, and the plate thickness on the delivery side of the next stand increases, but it cannot be controlled sufficiently depending on the output signal of the AGC / REF generator 1. , Compensation by forced reduction by prediction. FIG. 5 shows an increase in the plate thickness at the tail end of the rolled material product, which is considered to be the sum of the increases of the stands F1 to F6 as shown in FIG. In Fig. 6, # 1 is the tail end increase between the stands F1 and F2 # 2 is 〃 F2 to F3 〃 # 3 is 〃 F3 to F4 〃 # 4 is 〃 F4 to F5 〃 # 5 is 〃 F5 to F6 〃 Represents In FIG. 3, the relay 5-a is closed when the tail end of the front stand is pulled out, and the roll opening degree from the position detection counter 7 at that time is stored in the roll opening degree memory 4. On the other hand, the calculator 3 calculates the equation (1) based on the value from the tail end compensation value setting device 2 and various constants to convert the plate thickness compensation amount into a roll opening. Here, ΔS _n : n stand roll opening correction value Δh _Tn : n stand tail end compensation amount Q _n : n stand plasticity coefficient M _n : n stand mill constant The value converted to roll opening is the roll It is subtracted from the memory value from the opening memory 4 and becomes a control signal of the roll opening. The relay 5-b is closed until the tail end comes out of the front stand and then out of its own stand. Relays 5-b, 5-
When the control signal of the roll opening selected by c is input to the subtractor 8 together with the count value of the position detection counter 7 that counts the pulses emitted from the pulse oscillator 6, the deviation is output from the subtractor 8. The reference signal to the electric motor 12 is created by the calculator 9 which inputs this deviation.
This reference signal is converted into an analog signal by the digital-analog converter 10 and input to the thyristor device 11,
The electric motor 12 is driven to change the opening of the rolling roll 13 in steps according to the compensation value to control the plate thickness.

[Problems to be Solved by the Invention]

Since the conventional plate thickness control device for continuous rolling mills is configured as described above, the compensation value changes stepwise when the tail end of the rolled material passes through each stand, so the length of the tail end is uniform over the entire length. However, there was a problem that the yield of the product was bad because the plate thickness accuracy was not obtained. The present invention has been made to solve the above problems, and a plate thickness control device for a continuous rolling mill capable of obtaining a product with good yield and good yield accuracy at the tail end of a rolled material. The purpose is to get.

[Means for solving problems]

The strip thickness control device of the continuous rolling mill according to the present invention, when the tail end plate thickness of the rolled material is corrected by controlling the opening degree of the rolling roll according to the tail end compensation value, the tail end of the rolled material is The opening of the rolling roll is continuously changed by changing the tail end compensation value in an inclined shape until it comes out of the front stand and then out of its own stand so that the tail end has a predetermined plate thickness. .

[Action]

The tail end compensation value in the present invention is changed in an inclined manner so as to be successively increased, whereby the opening degree of the rolling roll is continuously changed, and the plate thickness of the tail end portion of the rolled material is made uniform.

【Example】

An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, 1 to 13 are the same components as those of the conventional plate thickness control device for a continuous rolling mill shown in FIG. 14 is a pulse transmitter attached to the roll rotating shaft to detect the speed of the rolled material, 15 is a digital speed measuring circuit,
The speed is calculated by counting the pulses from the pulse transmitter 14 (speed measuring means). Reference numeral 16 is an instrument (calculating means) for determining the change inclination of the tail end compensation value based on the speed of the rolled material from the digital speed measuring circuit 15, and 17 is an inclination for generating a signal of the change inclination determined by the operation unit 16. It is a signal generator (gradient signal generating means). Next, the operation will be described. In a continuous rolling mill, the tail end compensation value from when the tail end of the rolled material 18 passes through the front stand to when it passes through its own stand is used as an inclination signal as shown in Fig. 2 to prevent a sudden change between stand stands. To do. That is, the measured value V _{n of} the digital speed measuring device 15 which measures the speed of the rolled material based on the pulse from the pulse transmitter 14.
And the stand-to-stand distance l _n Ask for. Then, the moving time T _n between the stands and the tail end compensation value setting unit (tail end compensation value setting means) 2 calculates a tail end compensation value every time by the operation unit 16, and the operation result is calculated by the inclination signal generator 17. And enter, as shown in FIG.
When the tail end of the rolled material increases with a constant inclination from when it exits the front stand, and when it exits its own stand, a tilt signal is generated so as to obtain a predetermined plate thickness. Until the tail end of the rolled material passes through the front stand, the output signal of the AGC / REF generator (automatic plate thickness control signal generation means) 1 is supplied to the subtractor 8 and the tail end of the rolled material passes through the front stand. The relays 5-b, 5-- are provided so that the tilt signal from the tilt signal generating means is supplied to the subtractor 8 until it goes out of its own stand.
c is switched. As a result, the opening of the rolling roll of the self-stand is continuously changed by the tilt signal until the tail end of the rolled material leaves the former stand until it exits the self-stand, and the plate thickness of the tail end is made uniform. You can Incidentally, in the above embodiment, by the control output of the roll opening,
Although the one in which the electric motor is driven to set the roll opening is shown, a roll opening setting device by hydraulic pressure reduction may be used, and the same effect as that of the above-described embodiment is obtained.

【The invention's effect】

As described above, according to the present invention, when correcting the plate thickness at the tail end portion of the rolled material, the opening degree of the rolling roll of the rolled material until the tail end of the rolled material passes through the preceding stand until it leaves the own stand. Since it is configured to change continuously,
This has the effect of improving the plate thickness accuracy at the tail end of the rolled material and improving the yield.

[Brief description of drawings]

FIG. 1 is a block diagram showing a plate thickness control device for a continuous rolling mill according to an embodiment of the present invention, FIG. 2 is an explanatory view showing a tail end compensation amount in this device, and FIG. 3 is a conventional continuous rolling mill. FIG. 4 is a block diagram showing a plate thickness control device, FIG. 4 is a schematic diagram of a continuous rolling mill, FIG. 5 is a curve diagram showing an increase in plate thickness at the tail end of the rolled material, and FIG. 6 is a tail end of each stand. It is explanatory drawing which showed the plate thickness increase of. 2 is a tail end compensation setting device, 15 is a speed measuring circuit, 16 is a computing unit,
17 is a tilt signal generator and 18 is a rolled material. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A plate thickness control device for a continuous rolling mill for controlling a plate thickness of a tail end of a rolled material passing between a plurality of stands to be constant, and a control signal of a plate thickness of the rolled material while the preceding stand is engaged. And a tail end compensation value setting means for setting a tail end compensation value for correcting the thickness of the tail end of the rolled material when the tail end of the rolled material passes through the front stand. From the speed measuring means for measuring the speed of the rolled material, the inter-stand movement time corresponding to the measured speed and the set tail end compensation value, the tail end compensation value for the inter-stand movement time is almost Calculating means for determining a characteristic that increases with a constant inclination and reaches a set value of the tail end compensation value, inclination signal generating means for generating an inclination signal that changes according to the determined inclination, and the rolled material Until the tail end of the The opening signal of the rolling roll is controlled by the control signal from the automatic plate thickness control signal generating means, and the tilt signal from the tilt signal generating means is applied until the tail end of the rolled material passes through the front stand and passes through its own stand. And a switching means for continuously controlling the opening degree of the rolling roll according to the present invention.