JPH0354025B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for controlling the casting speed at the end of casting in a continuous casting machine. For more details,
The present invention relates to a control method in which an optimal casting speed deceleration speed pattern is selected in advance and the speed at the end of casting is reduced in accordance with the pattern.

(Prior Art) In a continuous casting machine, molten steel in a tundish is continuously cast to produce slabs. However, in order to maintain the quality of the slab at the end of casting, it is necessary to reduce the casting speed appropriately and stop the casting while leaving a predetermined small amount of molten steel in the tundish.

Until now, such deceleration control at the end of casting has often relied on manual operation. However, manual control has the disadvantage that the quality of the bottom part of the slab becomes unstable due to fluctuations in the casting speed, and that the work load is large.

Therefore, a method for automatically controlling the end of casting has been proposed based on the principle shown in FIG. The upper graph in the figure shows the change in the amount W of molten steel in the tundish over time t. After the supply of molten steel from the ladle indicated by arrow X ends, the amount W of molten steel gradually decreases.

At the time ta when the molten steel amount W has decreased to Wa, deceleration control of the pouring speed V (lower graph in the figure) is started. In other words, when the weight scale attached to the tundish detects that the remaining steel amount has become equal to Wa, the casting speed V becomes the steady casting speed.
After being decelerated from Vc at a constant deceleration for a predetermined time,
maintained at a constant value (graph abc).

After that, when it is detected that the molten steel amount W further decreases and becomes equal to the predetermined value Wc at time tc,
The casting speed V is further reduced and maintained at a constant value again (graph cde). The pouring is stopped at a time te when the amount W of molten steel further decreases and a predetermined value We is detected.

In this way, in the conventional casting completion control method shown in FIG. 4, the amount W of molten steel in the tundish is
The points at which predetermined values Wa, Wc, and We are reached are controlled as the deceleration start point, deceleration restart point, and casting stop point, respectively.

(Problem to be Solved by the Invention) Therefore, in the above-mentioned control method, when the steady casting speed Vc is small, it takes a long time from the start of deceleration to the stop, resulting in poor efficiency (see Figure 5). ). The same applies when the size of the slab is small.

On the other hand, if the steady pouring speed Vc or slab size is large, the portion bc that is maintained at a constant speed after deceleration,
The de time becomes extremely short (see Figure 6).

As described above, in the conventional casting completion control method, the pattern of temporal changes in the casting speed V is not constant. For this reason, it is unavoidable that the termination control takes more time than necessary and that the quality of the bottom part of the slab becomes uneven.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to overcome the drawbacks of the above-mentioned conventional methods for automatically controlling the end of casting. In particular, it is an object of the present invention to provide a casting completion control method that maintains high slab quality while reducing the time required for completion control as much as possible.

(Means for Solving the Problems) As a result of repeated research to achieve the above object, the inventors have obtained the following knowledge.

In other words, prior to termination control, a target pouring speed pattern is selected in advance, and if the speed is decelerated according to this pattern, the expected pouring amount from the start of deceleration to the stop is calculated, and the tundish It was discovered that if the deceleration control was started when the amount of molten steel in the mold became equal to this calculated value, the casting speed could be controlled almost faithfully to the previously selected pattern.

Thus, the gist of the present invention is to provide a casting completion control method for controlling the casting speed at the end of casting of a continuous casting machine that continuously casts molten metal in a tundish to form slabs. , Determining in advance a pattern of temporal changes in the casting speed from the start of deceleration to the stop of casting, which is a target in deceleration control; and Predicted casting weight from the start of deceleration to the time of stopping casting in the pattern. and when the measured weight of molten metal in the tundish matches the calculated predicted casting weight,
A casting completion control method comprising: starting deceleration control of the casting speed according to the pattern, and performing pattern following control of the casting speed with respect to the pattern.

In addition, in the above-mentioned invention, in order to make the remaining molten metal amount at the time of stopping pouring match a predetermined value while following the pattern as faithfully as possible even if there is a change in the pouring speed, etc., The pattern following control includes, after determining the target pattern in the deceleration control, detecting the difference between the specified casting speed of the pattern and the actual casting speed at a predetermined period; Calculating the amount of change in predicted casting weight based on the difference in pouring speed; Correcting the pattern of pouring speed according to the amount of change in predicted pouring weight; and Adjusting the pouring speed by the corrected pattern. Preferably, this is done by controlling and.

Furthermore, in the present invention, if the dimensions of the slab change after determining the target pattern in the deceleration control, the pattern following control may be performed after determining the target pattern in the deceleration control. , periodically detecting changes in slab dimensions, calculating a predicted change in cast weight based on the detected change in slab size, and adjusting casting according to the change in predicted cast weight. It is preferable to perform the following steps: correcting the casting speed pattern; and controlling the casting speed using the corrected pattern.

According to another aspect of the present invention, there is provided a casting completion control method for controlling the casting speed at the end of casting of a continuous casting machine that continuously casts molten metal in a tundish into slabs. Determining in advance a pattern of temporal changes in pouring speed from the start of deceleration to the stop of pouring, which is targeted in deceleration control, and the pattern includes the start of deceleration, the stop of deceleration, and the start of deceleration again. Calculating the predicted casting weight from the start of deceleration to the casting stop in the pattern; At the time when the measured weight of the molten metal in the tundish matches the calculated predicted casting weight,
Starting control of deceleration of the casting speed according to the pattern; Calculating a predicted casting weight from the start of re-deceleration to the time of stopping casting in the pattern; The measured value of the molten metal in the tundish is It is also possible to control the casting speed according to the pattern by starting the re-deceleration at a time point from the start of deceleration to the stop of casting when the predicted casting weight coincides with the predicted casting weight.

(Operation) In the present invention, a target pattern of deceleration is determined in advance before entering deceleration control. Furthermore, when controlling according to this target pattern, the predicted casting weight from the start of deceleration to the stop is calculated, and deceleration control is started when the measured weight of molten metal in the tundish matches the calculated value. do. Therefore, the time point at which deceleration starts can be made to accurately match the time point at which deceleration should start in order to control deceleration according to the pattern. As a result, after that, deceleration control can be realized almost faithfully to the pattern by simply controlling the deceleration, constant value maintenance speed, constant value maintenance time, etc. to values determined in advance in the pattern.

Preferably, the values (parameters) determined by the pattern are corrected in accordance with deviations in casting speed from the pattern or changes in slab dimensions. Therefore, even when these changes occur, the amount of metal in the tundish at the time of stopping can be made to match the predetermined value while making the casting speed faithfully follow the pattern.

In addition, if the predicted casting weight from the start of re-deceleration to the stop of pouring is calculated, and the re-deceleration is started when the measured value of the weight of molten metal in the tundish matches the calculated value, the correction is especially necessary. Control faithful to the pattern is possible even without this.

(Example) Next, an example of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a block diagram of an example of a device for implementing the control method according to the present invention, and shows a case in which the present invention is applied to a continuous casting machine for molten steel having two molds.

A tundish 10 of a continuous casting machine 1 pours molten steel injected from a ladle 11 into first and second molds 1.
The slabs 14 and 15 are produced by continuously casting into the slabs 2 and 13. While the supply of molten steel from the ladle 11 continues, pouring is performed at an almost constant steady pouring speed, but when the supply of molten steel from the ladle 11 ends,
When the pouring approaches its completion, the pouring is controlled to be decelerated and stopped, leaving a predetermined weight of molten steel in the tundish 10.

This casting completion control will be explained below for each block.

Operation of the management section 2 The management section 2 consists of, for example, a host computer, and records information such as the planned charge number, slab dimensions, steel type,
Manage the number of slabs, etc. Furthermore, the management unit 2 determines an appropriate speed pattern for deceleration based on these values and the like. It is preferable that the management unit 2 stores a large number of speed patterns and selects an appropriate one from among these. The management section 2 outputs the slab dimensions and the determined speed pattern to the weight calculation section 3 and the control calculation section 4.

FIG. 2 shows the time t of the casting speed into the first and second molds 12 and 13 determined by the management section 2.
Each graph of the pattern of change for V ₁
=V ₁ (t) and V ₂ =V ₂ (t).

The casting speed pattern V ₁ =V ₁ (t) for the strand on the 12 side of the first mold is from the steady casting speed Vc ₁
It starts decelerating at point A ₁₁ , passes through A ₂₁ , A ₃₁ , and A ₄₁ and stops at A ₅₁ (the times corresponding to A ₁₁ to A ₅₁ in graph V ₁ are expressed as t ₁₁ to t ₅₁ , respectively). ).

From A ₁₁ to A ₂₁ , V ₁ is decelerated at a predetermined deceleration K ₁₁ , and from A ₂₁ to A ₃₁ , it is maintained at a predetermined speed V ₁₁ for a predetermined time.
T ₁₁ maintained. The deceleration starts again from A ₃₁ (predetermined deceleration K ₂₁ ), and when the predetermined speed V ₂₁ is reached, T ₂₁
time, maintained at a constant speed (A ₄₁ -A ₅₁ ).

The above pattern V ₁ is determined by deceleration K ₁₁ , K ₂₁ , maintenance speed V ₁₁ , V ₂₁ , maintenance time T ₁₁ , T ₂₁ , and steady casting speed Vc ₁ . Yotsute Management Department 2
is the steady pouring speed Vc ₁ and the dimensions (width) of the slab 14
Parameters K ₁₁ , K ₂₁ , V ₁₁ , V ₂₁ , depending on S ₁ etc.
T ₁₁ and T ₂₁ are determined and output together with Vc ₁ and S ₁ .

Here, the reason for using the pattern shown in FIG. 2 and the selection of the values of each parameter by the management section 2 will be briefly explained.

In order to finish casting in a short time and improve work efficiency, it is preferable that the total deceleration control time Tt ₁ is short. For this, shorten T ₁₁ , T ₂₁ and shorten K ₁₁ , K ₂₁
must be taken large. However, there are limits to the range of values that these parameters can take, as described below. Therefore, the management unit 2 selects these parameters so as to make Tt ₁ as short as possible within the limited range.

When K ₁₁ and K ₂₁ are set large (that is, when the casting speed is suddenly decreased), it becomes difficult to control the level of the mold 12. Therefore, there is a practical upper limit to the possible values of K ₁₁ and K ₂₁ (for example, 1.0 m/min ² ).
There is.

Moreover, if the deceleration period (t ₁₁ to t ₂₁ ) continues for too long, blow-up (rising hot water surface) occurs. To prevent this, _T11 must also be set to a predetermined value (for example, 0.5 to
1.0 min) or more. In addition to the same reason for T ₂₁ , in order _to stabilize the quality of the bottom part of the slab 14, it is
2 min or more) must be cast. The lower limit of T ₂₁ is a value determined by the characteristics of the continuous casting machine 1, the type of steel, etc.

The second mold 13 as shown in FIG.
The pattern V ₂ of the casting speed is also determined in the same manner as V ₁ . That is, _the management unit ₂ determines _{the parameters K 12 ,} K ₂₂ , V ₁₂ , Determine V ₂₂ , T ₁₂ , T ₂₂ ,
These are output together with Vc ₂ and S ₂ . Here,
K ₁₂ is the deceleration from A ₁₂ to A ₂₂ in the figure, K ₂₂
is the deceleration of A ₃₂ to A ₄₂ , V ₁₂ and V ₂₂ are respectively
A ₂₂ to A ₃₂ , A ₄₂ to A ₅₂ maintenance speed, T ₁₂ , T ₂₂
is the maintenance time corresponding to these maintenance speeds.
Further, t ₁₂ to _{t 51} are times corresponding to A ₁₂ to A ₅₂ , respectively.

In FIG. 2, the end times (t ₅₁ , t ₅₂ ) of the speed patterns V ₁ and V ₂ of the first mold 12 and the second mold 13 are made to match (hereinafter, t ₅₁ = t ₅₂ = t ₀
far). Since the total control times Tt ₁ and Tt ₂ are different, the start times (t ₁₁ =t ₁ and t ₁₂ =t ₂ ) do not match.
However, the start and end times may both be made to coincide, or both may be controlled to be shifted. In addition, especially when the dimensions S ₁ and S ₂ of the slabs 14 and 15 match, V ₁ and V ₂ can be made into exactly the same pattern [V ₁ (t)=V ₂ (t)].

In this way, the management unit 2 determines the speed patterns V ₁ and V ₂
The values to determine are Vc ₁ , V ₁₁ , V ₂₁ , K ₁₁ , K ₂₁ ,
T ₁₁ , T ₂₁ and Vc ₂ , V ₁₂ , V ₂₂ , K ₁₂ , K ₂₂ ,
T ₁₂ and T ₂₂ and S ₁ and S ₂ as slab dimensions are outputted to the weight calculation section 3 and the control calculation section 4.

Operation of Weight Calculation Unit 3 The weight calculation unit 3, which receives these values from the management unit 2, calculates from the deceleration start time _t1 of the strand on the first mold 12 side to the stop time of both molds 12 and 13.
The predicted casting weight W ₁ in both molds 12 and 13 up to t ₀ is calculated using the following formula (both molds 1
It is assumed that the control is performed so that the pouring into the pipes No. 2 and No. 13 is stopped at the same time).

W ₁ = W ₁₁ + W ₁₂ + W ₀ Here, W ₀ is the amount of molten steel that should remain in the tundish 10 when pouring is stopped (t = t ₀ ), and W ₁₁ ,
W ₁₂ is the predicted weight of casting into the first and second molds 12 and 13 during the period from t ₁ to t ₀ , respectively. Therefore, W ₁₁ and W ₁₂ are respectively given by the following formulas.

W ₁₁ =ρ・S・S ₁・∫ ^t0 _t1 V ₁ (t)dt W ₁₂ =ρ・S・S ₂・∫ ^t0 _t1 V ₂ (t)dt where ρ is the density of molten steel and S is the slab is the thickness (assumed to be constant).

Similarly, the predicted weight of casting into the first and second molds 12, 13 from the deceleration start time _t2 to _t0 of the strand on the second mold 13 side is calculated using the following formula.

W ₁ = W ₂₁ + W ₂₂ + W ₀ Here, W ₂₁ and W ₂₂ are the above period (t ₂
to t ₀ ), the first and second molds 12,
W ₂₁ = ρ・S・S ₁・∫ ^t0 _t2 V ₁ (t)dt W ₂₂ = ρ・S・S ₂・∫ ^t0 _t2 V ₂ (t)dt It will be done. (However, if the total deceleration control periods Tt ₁ and Tt ₂ of both strands are equal and t ₁ = t ₂ , W ₁
= W ₂ , and there is no need to calculate W ₂ separately. ) The weight calculation unit 3 outputs these predicted casting amounts W ₁ and W ₂ to the control calculation unit 4.

The basic deceleration control operation of the control calculation unit 4 is performed according to the following steps (see Fig. 2).

(A ₀ ) The control calculation unit 4 actually measures the weight W of molten steel in the tundish 10 based on the input from the weight scale 5 attached to the tundish 10.

( _A11 ) The measured weight W is compared with the predicted weight _W1 , and when the two become equal, the control speed pattern signal _V1 of the strand on the first mold 12 side is started to be decelerated at a predetermined deceleration _K11 .

(A ₁₂ ) Similarly, when W becomes equal to W ₂ , the second
Start decelerating the control speed pattern signal _V2 of the strand on the mold 13 side at a predetermined deceleration _K12 .

(A ₂₁ ) When V ₁ becomes equal to V ₁₁ , the deceleration of V ₁ is stopped and the constant value V ₁₁ is maintained for T ₁₁ time.

(A ₂₂ ) Similarly for V ₂ , T ₁₂ hours after deceleration and stop.
Maintained at V ₁₂ .

(A ₃₁ ) V ₁ resumes deceleration at the predetermined deceleration K ₂₁ .

(A ₃₂ ) V ₂ resumes deceleration at the predetermined speed K ₂₂ again.

(A ₄₁ ) Stop the deceleration of V ₁ at V ₂₁ and maintain a constant value for T ₂₁ time.

(A ₄₂ ) Stop the deceleration of V ₂ at V ₂₂ and maintain a constant value for T ₂₂ hours.

(A ₅₁ ) Set V ₁ to 0.

(A ₅₂ ) Set V ₂ to 0.

The values V ₁ and V ₂ determined above are output to the speed setting section 6. Further, the correction control operation of the control calculation unit 4 will be described later.

Operation of speed setting section 6 automatic control conditions, i.e. (a) The casting speed setting is under automatic control.

(b) The speed pattern has been set by the management unit 2.

(c) The weight of molten steel in the tundish 10 is greater than a predetermined value.

(d) It is being cast.

If all of the above are satisfied, V ₁ and V ₂ inputted from the control calculation unit 4 are output as they are to the speed control unit 7 as the control speed of each strand. .

On the other hand, if the automatic control conditions (a) to (d) are not satisfied, a warning signal is generated to the operator, the speed is switched to manual speed setting, and the manually set speed is output to the speed control section 7.

Operation of Speed Control Unit 7 The speed control unit 7 controls the casting speed of each strand using the pinch rollers 16 and 17 to the respective control speed input from the speed setting unit 6. That is, the speeds of the pinch rollers 16 and 17 are controlled to the respective target values input from the speed setting section 6 using the inputs from the speedometers 18 and 19 as feedback signals.

Correction Control Operation of Control Calculation Unit 4 The control calculation unit 4 is always inputted with slab dimensions S ₁ , S ₂ and actual measurement values of pouring speed from speedometers 18 and 19 . If the slab dimensions S ₁ and S ₂ change after the speed pattern is determined by the control unit 2, or if the actual casting speed of each strand takes a value different from the target value determined by the speed pattern, the above An error occurs in the predicted weights W ₁ and W ₂ . Control calculation unit 4
checks the difference between the measured value and target value of pouring speed and the existence of changes in S ₁ and S ₂ at predetermined intervals, and if these are detected, the parameters of the speed pattern are corrected under the following conditions. do.

(1) The amount of molten steel remaining in the tundish 10 when pouring is stopped is made equal to a predetermined value W ₀ .

(2) First, the deviation from the speed pattern determined by the management section 2 is made as small as possible.

More specifically, among the parameters of the speed pattern, for example, only T ₁₁ , T ₂₁ , T ₁₂ , and T ₂₂ are changed,
Other parameters (K ₁₁ , K ₂₁ , V ₁₁ , V _{21 ,} etc.) can be fixed to correct the pattern. Next, correction when the casting speed of the strand on the first mold 12 side deviates from the initially set speed pattern will be specifically explained with reference to FIG. 3.

The actual casting speed W ₁ ′ of the strand on the side of the first mold 12 is not decelerated from Vc ₁ to V ₁₁ and becomes a constant speed V ₁₁ ′ at point A ₂₁ ′, which is detected at the point indicated by arrow Y. do.

First, the control calculation unit 4 calculates the increment ΔW of the predicted casting weights W ₁ and W ₂ caused as a result of this. An approximate value of this increment ΔW can be calculated, for example, using the formula ΔW=ρ·S·S ₁ ·(V ₁₁ ′−V ₁₁ )·T ₁₁ .

Next, the amount of reduction ΔT of the parameters T ₁₁ and T ₁₂ is calculated so as to exactly cancel out the increase ΔW in the predicted pouring amount. (In other words, shorten T ₁₁ and T ₁₂ by ΔT and
T ₁₁ ′ and T ₁₂ ′ are set so as to cancel out the increment ΔW in the predicted pouring amount. ) This shortening amount ΔT is calculated using the following formula.

ΔW=ρ・S・S ₁・V ₁₁・ΔT +ρ・S・S ₂・V ₁₂・ΔT That is, ΔT=[S ₁・(V ₁₁ ′−V ₁₁ )・T ₁₁ ]/(S ₁・V ₁₁ +S ₂・V ₁₂ ) T ₁₁ ′=T ₁₁ −ΔT T ₁₂ ′=T ₁₂ −ΔT The control calculation unit 4 was calculated in this way.
Corrected speed patterns V ₁ ′ and V ₂ ′ (see Figure 3) with T ₁₁ ′ and T ₁₂ ′ as new parameters, respectively, are V ₁ and V ₂
is used instead of to control the speed of each strand. As a result, the above-mentioned conditions (1) and (2) can be satisfied.

Furthermore, if a deviation in the casting speed is detected after points A ₃₁ and A ₃₂ , the parameters T ₂₁ and T ₂₂ are corrected.

Other aspects of the operation of the weight calculation unit 3 and the control calculation unit 4 In the above, the weight calculation unit 3 calculated only the predicted casting weights W ₁ and W ₂ from t ₁ to t ₀ or from t ₂ to t ₀ . However, in the embodiment described here, the weight calculating section 3 further calculates the total expected casting weight W ₃ of both strands from t ₃₁ to t ₀ and the weight W ₄ from t ₃₂ to t ₀ (these calculation formulas are (This is omitted as it is the same as for W ₁ and W ₂ ).

The control calculation unit 4 compares W ₁ and W ₂ with the measured weight W for the start of deceleration at A ₁₁ and A ₁₂ in the same way as in the above case. However, the re-start of deceleration (A ₃₁ , A ₃₂ ) is also performed by comparing W ₃ and W ₄ calculated by the weight calculating section 3 with the measured weight W.
That is, when W becomes equal to W ₃ and W ₄ , respectively, deceleration of V ₁ and V ₂ is restarted at decelerations K ₂₁ and K ₂₂ .

Also, when W becomes equal to W ₀ , V ₁ and V ₂ are reduced to 0.
shall be.

According to this mode of operation, not only the deceleration start times t ₁ and t ₂ but also the deceleration restart times t ₃₁ , t ₃₂ and the stop time t ₀ are controlled based on the measured weight W. No corrective action is required.

Specific Examples of Control The following table compares specific examples of casting completion control according to the method of the present invention with those based on the conventional method. The method of the present invention uses the apparatus having the configuration shown in FIG. In the casting completion control method according to claim 3, the present invention example 3 is the casting completion control method according to claim 4, and furthermore, the present invention example 4 is the casting completion control method according to claim 1. Each was controlled using the termination control method.

In addition, with conventional methods, workers are unable to respond to changes in conditions such as slab size and casting speed.
Molten steel amount in Fig. 4: Wa, Wb and Wc, pouring speed in Fig. 2: V ₁ and V ₂ , deceleration:
K ₁ and K ₂ are determined in advance to appropriate values, and when the amount of molten steel reaches Wa, the casting speed starts to be reduced aiming for the casting speed V ₁ , and then deceleration and stop are performed. controlled. Note that the same control was applied to Wb and subsequent parts. The table shows a case where the slab thickness S was constant at 270 mm, and both strands were controlled to finish casting with the same speed pattern, and the strand on the second mold side was stopped in advance, and only the strand on the first mold side was controlled to finish casting. Indicate the case. In the table, Wa means W ₁ (=W ₂ ) in the present invention, Wb is the amount of molten steel in the tundish 10 at t ₃₁ (=t ₃₂ ), and Wc is Wo.

The results are summarized in the table below. As is clear from the table below, according to the conventional method, the maintenance times T ₁ and T ₂ during deceleration control and the total deceleration control time Tt are not constant, whereas according to the present invention, the maintenance time T ₁
= 0.5 (min), T ₂ = 2.0 (min), and Tt = 3.9 (min).

■■■ Turtle Shell [0022] ■■■ ■■■ Turtle Shell [2022] ■■■ (Effects of the Invention) In the present invention, target speed patterns V ₁ and V ₂ are determined in advance before the start of deceleration. , the predicted casting weight from deceleration start times t ₁ and t ₂ to stop t ₀ assuming that these patterns V ₁ and V ₂ are followed.
W ₁ and W ₂ are calculated. Therefore, Tandishyu 10
The actual weight W within is measured, and this measured weight W is W ₁ , W ₂
When it becomes equal to , deceleration begins.

Furthermore, if necessary, the speed pattern is corrected according to changes in slab dimensions S ₁ and S ₂ and actual casting speed. Alternatively, the start of deceleration again is also controlled based on the measured weight W.

As a result, the slab dimensions S ₁ and S ₂ and the casting method (simultaneous casting of both strands, casting the strands under both molds 12 and 13 at the same time, or casting only the strands on the side of the first mold 12 or second mold 13) Regardless of whether one strand is being cast or not, the casting speed is controlled faithfully to the target speed pattern. In the conventional method, the time required to maintain a constant speed varied greatly depending on the slab size and casting method. This will be clear from the table above.

[Brief explanation of drawings]

Fig. 1 is a block diagram of a system in which the control method according to the present invention is implemented in a two-strand continuous casting machine; Fig. 2 is a graph of an example of a target speed pattern in the system of Fig. 1; 3 is a graph of an example of the actual casting speed under the target speed pattern of FIG. 2 and the speed pattern after correction; FIG. 4 is a graph showing the principle of the conventional control method; and FIG. FIG. 6 is a graph of an example of change in actual casting speed under the control method of FIG. 4. 1: Continuous casting machine, 10: Tendishu, 11:
Ladle, 12, 13: Mold, 14, 15:
Slab, 16, 17: Pinch roller, 18, 19:
Speedometer, 2: Management section, 3: Weight calculation section, 4: Control calculation section, 5: Weight scale, 6: Speed setting section, 7: Speed control section.

Claims (1)

[Scope of Claims] 1. A casting completion control method for decelerating the casting speed at the end of casting of a continuous casting machine that continuously pours molten metal in a tundish into slabs, comprising: Determining in advance the targeted pattern of temporal changes in casting speed from the start of deceleration to the stop of casting, and calculating the predicted cast weight from the start of deceleration to the time of stopping casting in this pattern. And, at the time when the measured weight of molten metal in the tundish matches the calculated predicted casting weight,
A casting completion control method, comprising: starting deceleration control of the casting speed according to the pattern, and performing pattern following control of the casting speed with respect to the pattern. 2. The pattern following control includes, after determining the target pattern in the deceleration control, detecting at a predetermined period the difference between the casting speed specified in the pattern and the actual casting speed; Calculating the amount of change in predicted casting weight based on the difference in casting speed; Correcting a pattern of casting speed according to the amount of change in predicted casting weight; and Adjusting the casting speed according to the corrected pattern. A casting completion control method according to claim 1, which is carried out by controlling. 3. The pattern following control includes, after determining the target pattern in the deceleration control, periodically detecting changes in the dimensions of the slab, and determining predicted casting weight based on the detected changes in the dimensions of the slab. Claim No. 1, which is performed by calculating the amount of change, correcting the pattern of casting speed according to the amount of change in predicted casting weight, and controlling the casting speed based on the corrected pattern. The casting completion control method according to item 1. 4. A casting completion control method for decelerating and controlling the pouring speed at the end of pouring of a continuous casting machine that continuously pours molten metal in a tundish into slabs, which is aimed at in deceleration control. determining in advance a pattern of temporal changes in casting speed from the start of deceleration to the stop of casting; the pattern includes a start of deceleration, a stop of deceleration, and a start of deceleration again; and Calculate the predicted casting weight up to the point when the casting stops, and when the measured value of the weight of molten metal in the tundish matches the calculated predicted casting weight,
Starting control of deceleration of the casting speed according to the pattern; Calculating a predicted casting weight from the start of re-deceleration to the time of stopping casting in the pattern; The measured value of the molten metal in the tundish is A casting completion control method comprising: starting the deceleration again at a time point from the start of deceleration to the stop of casting when the predicted casting weight matches the predicted casting weight, and controlling the casting speed according to the pattern.