JPH0313230A - Rolling pitch controller - Google Patents

Abstract

PURPOSE:To correct an inter-pitch control by which tension and push-in are not generated at the time when a rolling material is bitten into the next rolling mill by bringing the tip of the rolling material to tracking and executing a speed correction by a rolling pitch controller. CONSTITUTION:In a rolling pitch controller for controlling a rolling interval time of preceding and succeeding rolling materials 3, 4 rolled continuously, by providing a computing element 14 for bringing the tip of the rolling material to tracking and calculating an arrival predicting time to the next rolling mill, a correction quantity limit value computing element 20 for setting the speed correction quantity at the time when the rolling material arrives at the next rolling mill to zero, and a proportional integrator 19 for correcting a speed of the rolling mill, based on its output, a correct speed correction is executed, a correction value of a target point arrival time always becomes zero, and a correct inter-pitch control can be executed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a rolling pitch control device in continuous rolling equipment for steel bars, wire rods, thick plates, and the like.

(Prior Art) FIG. 3 shows an example of a conventional rolling pitch control device for controlling the rolling interval time, that is, the rolling pitch, between a preceding rolled material and a subsequent rolled material in a continuous rolling facility.

In Fig. 3, 1 is the N rolling mill, 2 is the (N+1) rolling mill, 3 is the leading rolled material, 4 is the trailing rolled material, 5 is the driving motor of the N rolling mill, 6 is the load detector, and 7 is the rolling mill. 8 is a rolling material speed detector; 9 is a tracking device for determining the remaining length Q from the tip of the trailing rolling material 4 to the (N+1) rolling mill; 10 is a correction amount calculator that calculates the correction amount cutting timing from the remaining length 2 and rolling speed V, 11 is a switch that turns on and off the correction amount ΔV, and 12 is the speed of N rolling mill 1 before adding the correction amount. Standard V,
17 is the target pitch setting value T8.18 is the correction amount Δ
22 is a ramp function generator;
23 is an adder, and 24 is a motor control device that controls the drive motor 5 of the N rolling mill.

When N rolling mill 1 and (N+1) rolling mill 2 are rolling the same rolled material at the same time, the speed settings of both rolling mills are set so that the rolled material between both rolling mills is tension-free. It will be done.

Therefore, the pitch time between the leading rolled material and the trailing rolled material in N rolling mill 1 is the same at the position of (N+1) rolling mill 2 if there is no change in the speed of N rolling mill 1 and (N+1) rolling mill 2. This is the pitch time.

Interpitch control is performed by applying the above principle, and before the trailing rolled material reaches the (N+1) rolling mill 2, the speed of the N rolling mill 1 is varied to control the interpitch time.

When the tail end of the preceding rolled material 3 passes through the N rolling mill 1, the load detector 6 detects this, the interval time measuring device 7 adds up the time, and the trailing rolled material 4 bites into the N rolling mill 1. The pitch time T is measured until then.

During this period, the correction amount calculator 18 inputs the pitch time T, the reference speed S, the acceleration/deceleration rate α, the distance L between rolling mills, and the pitch between settings T8, and calculates the correction amount ΔV at the start of the detection by the load detector 6.
is calculated using the following formula.

Here : Acceleration/deceleration rate :Reference speed L: Distance between rolling mills T8: Pitch between settings T: Pitch between actual results ΔT = TB-T It is.

On the other hand, a tracking device that uses the rolling mill speed detector 8 and load detector 6 as input! 9, the tip of the trailing rolled material 3 and (N
+1) The remaining length Q up to the rolling mill 2 is determined, and this human power Q, reference speed V, and correction amount ΔV are input into the correction amount calculator 10, and the pitch correction amount cut length Q is calculated using the following formula 0. When the relationship between the correction amount cut length 2cm and the remaining tracking length Ω satisfies the following equation 0, a correction amount clear signal is output to the switch 11.

Q<Qx...■ Here, Q = Tracking remaining length α: Acceleration/deceleration rate ΔV: Interval pitch correction amount 1j: Reference speed The above output operates the switch 11 that turns on/off the correction amount, performs on/off, generates a correction value 13 actually used by a ramp function generator 22 of acceleration/deceleration rate α,
This correction value 13 and the reference speed V are added by an adder 23 to become the speed reference for the electric motor 5 for the N rolling mill.

Figure 4 shows the change in the correction value 13 when the actual pitch is larger than the set pitch, and the control start point a is when the trailing rolled material is bitten by the N rolling mill, and the acceleration of α is The figure shows that control is performed so that the deceleration rate increases at a rate of Δ up to Δ, decreases at a deceleration rate of α from the correction amount cut-off timing point b, and becomes zero at the control end point C.

(Problem to be Solved by the Invention) However, in the conventional device described above, the correction amount ΔV is obtained at the start of load detection at the start of control, so if the reference speed of the rolling mill changes after the start of control, the The correction amount for the minute is ignored, and this becomes an error in the pitch time.

Also, even if the reference speed increases after decelerating at the deceleration α by cutting the correction amount ΔV, the control end point will be reached earlier than the predicted control end point time and before the correction amount becomes zero, so the correction There is a risk that the remaining amount (N+1) will get caught in the rolling mill, causing indentation between the rolling mills and having an adverse effect on the rolled material.

The present invention provides a rational rolling pitch control device that always performs accurate pitch correction according to the speed even if there is a change in the reference speed after the start of pitch control, and that the amount of correction is always zero at the end of the control. is intended to provide.

(Structure of the invention) (Means and effects for solving the problem) In order to achieve the above object, the present invention provides that the trailing rolled material is
A predicted arrival time calculator is provided that calculates the predicted arrival time t from when the tip of the rolled material reaches the (N+1) rolling mill after it is bitten by the rolling mill using the following formula, and the amount of correction is limited. The correction amount limit value is calculated as the maximum value of the correction amount at which the speed correction amount becomes zero at the acceleration/deceleration rate α by the time the tip of the rolled material is bitten by the (N+1) rolling mill using the following 0 formula. A calculation unit is provided, and a load elapsed time integrator and a proportional integrator that proportionally integrates the deviation that becomes the correction output are installed.This ensures that even if the reference speed changes after the start of pitch control, the correction amount will always be zero at the control end point. I'm trying to make it happen.

Q = remaining length tracking J: Reference speed ΔV: pitch correction amount α: Acceleration/deceleration rate (Example) An embodiment of the present invention is shown in FIG.

In FIG. 1, 1 is the N rolling mill, 2 is the (N+1) rolling mill, 3 is the leading rolled material, 4 is the trailing rolled material, 5 is the drive motor,
6 is a load detector, 7 is a pitch time measuring device, 8 is a rolled material speed detector, 9 is a tracking device, 12 is a reference speed,
13 is a speed correction value; 14 is a predicted arrival time calculator that calculates the time t for the trailing rolled material 4 to reach the (N+1) rolling mill 2;
15 is a predicted arrival time storage device that stores the value of the predicted arrival time t at the start of control; 16 is an elapsed time integrator that adds up the time since the trailing rolled material 4 is bitten in the N rolling mill 1;
17 is the pitch time setting value T which is the target pitch time.
8.19 is a proportional integrator that proportionally integrates the deviation of the inter-pitch time; 20 is a correction amount limit value calculator that calculates a control value of the correction amount; 21 is a correction amount limiter; 23, 26, and 27 are adders;
24 is a motor control device, and 25.28 is a subtracter.

With the above configuration, the actual pitch time T between the N rolling mill 1 after the rear end of the preceding rolled material 3 passes through and the leading end of the trailing rolled material 4 is bitten is measured by the pitch time measuring device 7, and ,
By inputting the remaining length Q, reference speed V, and acceleration/deceleration rate α from the tracking device 9, the trailing rolled material 4 is (N+1
) The time t until reaching the rolling mill 2 is calculated by the predicted arrival time calculator 14.

This calculation result t and the elapsed time since the trailing rolled material 4 was bitten into the N rolling mill 1 measured by the elapsed time measuring device are added by an adder 27 to obtain the predicted inter-pitch time.

On the other hand, the value t of the predicted arrival time storage unit 15 at the start of control and the difference pitch setting time T3 subtracted from the difference pitch time actual value T by the subtractor 25 are added together by the adder 26, and from the result, the above prediction is made. A subtracter 28 subtracts the inter-pitch time to obtain a deviation, this deviation is passed through a proportional integrator 19 as a correction amount target value, and this correction amount target value is further limited by the output of a correction amount limit value calculator 20, This is added to the reference speed V as an actual pitch correction amount, and the speed of the electric motor 5 is controlled using this as the speed reference of the motor control device 24.

FIG. 2 is a time chart showing changes in the speed correction amount in the present invention, and when the predicted pitch is longer than the target pitch by Δt when the trailing rolled material of the N rolling machine is bitten, the correction amount increases. When the inter-pitch decreases and approaches the target value, the correction amount becomes zero, and when the reference speed increases at point e, the target inter-pitch decreases, the correction amount decreases, and the correction amount continues until there is no change in the reference speed. is output.

〔Effect of the invention〕

As explained above, according to the present invention, the tip of the material is tracked to determine the remaining length to the target point, the time to reach the target point is determined from the current speed and the remaining length, and the speed is determined based on this. Since the correction is performed, even if the reference speed changes after the start of control, an appropriate speed correction for pitch control will be made, and the correction value will always be zero when the target point is reached, ensuring that the rolled material is Appropriate pitch control is possible without causing tension or pushing when the rolling mill is bitten by the next rolling mill.

[Brief explanation of drawings]

FIG. 1 is a system diagram showing an embodiment of the present invention, and FIG. 2 is a time chart showing an example of the operation of the present invention. FIG. 3 is a system diagram showing an example of a conventional rolling pitch control device, and FIG. 4 is a time chart showing an example of the operation of the conventional device. 1...N rolling mill 2...(N+1) rolling mill 3
... Leading rolled material 4... Following rolling material 5... Drive motor 6... Load detector 7... Interval pitch time measuring device 8... Rolled material speed detector 9... Tracking Device 12...Reference speed 13
... Speed correction value 14 ... Predicted arrival time calculator 1
5... Estimated arrival time saver 17... Interval pitch setting value 18... Correction amount calculator 1
9... Proportional integrator 20... Correction amount limit value calculator 21... Correction amount limiter 22... Ramp function generator 23, 26.27... Adder 24... Motor control device 25, 28...subtractor

Claims (1)

[Claims] In a rolling pitch control device that controls the rolling interval time between the preceding rolled material and the subsequent rolled material to a required value, the tip of the rolled material is tracked and the rolling pitch is controlled after the rolled material is bitten by the rolling mill. A predicted arrival time calculator that calculates the predicted arrival time until reaching the next rolling mill, and a predicted arrival time calculator that calculates the predicted arrival time until the rolled material reaches the next rolling mill, assuming that the necessary speed correction is given at a predetermined acceleration/deceleration rate within the above predicted time. A correction amount limit value calculator that calculates a correction amount limit value such that the correction amount becomes zero when the correction amount limit value is reached, and a proportional integrator that corrects the speed of the rolling motor based on the output of the correction amount limit value calculator. A rolling pitch control device characterized by: