JPH062956B2 - Central speed automatic control method for continuous processing line such as pickling line - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for automatically controlling the central speed of a continuous processing line such as a continuous pickling line for strip (thin steel sheet).

(Prior Art) Generally, in a continuous strip processing line, the strip is stopped on the inlet side and the outlet side by a coil connecting operation such as welding on the line inlet side and a coil dividing operation on the line outlet side. For this reason, a strip storage device is provided on the inlet and outlet sides of the central processing unit, and the strip storage device temporarily stores the strips, and even when the inlet and outlet sides are stopped, running of the strip in the central portion of the continuous processing line is performed. Operate continuously without stopping.

The storage amount of the strip storage device is usually determined according to the stop time in the input / output work, but this stop time differs depending on the condition of the material and the skill of the worker. Therefore, the processing line is usually operated while changing the central speed according to the progress of work and the amount of storage in the storage device.

As a method for controlling the central speed of the strip in such a continuous processing line, there is a method proposed in Japanese Patent Publication No. 58-5991. This control method calculates according to the input and output side "remaining expected stop time" at each time when the preset work division is completed and the completion signal is detected, and the storage amount of the strip storage device at that time. The "remaining effective time" is calculated, the two are compared, and the central speed is corrected so that the difference between the remaining expected time and the remaining effective time becomes zero.

(Problems to be solved by the invention) However, in this control method, when an unexpected situation such as a cut-down of a defective portion of the strip occurs in a preset work classification and the work is delayed, the expected stop work time is The signal indicating the completion of the work of the work section is not detected even after the passage of. Therefore, at this point, the central speed is not corrected and is maintained at the high level of the central speed in the previous stage.

Therefore, when the signal indicating the completion of the work of the work section is detected, the remaining effective strip storage amount is significantly small, and the central speed must be rapidly decelerated and corrected. In extreme cases, it is necessary to stop the strip running in the central part. In order to eliminate this inconvenience,
Assuming these unforeseen situations, it is necessary to set a large margin travel distance for the strip storage amount and lengthen the strip storage device storage amount, which causes problems such as increased equipment costs and difficult maintenance. Occurs.

It is an object of the present invention to provide a method that overcomes the problems of the prior art.

(Means for Solving Problems) Therefore, the inventors of the present invention have made repeated studies to develop a system with good responsiveness that avoids rapid speed correction, delaying the completion of work in each work segment, and predicting the completion time. If the signal indicating work completion is not generated even after the
The present invention has been completed, knowing that the speed control can be smoothly performed by correcting the central speed at a predetermined short time pitch and updating the control speed each time.

Therefore, the gist of the present invention is that in a continuous strip processing line such as a pickling line equipped with a strip storage device, a plurality of required work sections (1) to ( n), and set the expected work time T _{1 to} T _n for each of the work categories, and actually stop the work in each work category (i) (where i = 1, ..., N). Generating a signal S _i indicating work completion at the time of completion, the expected work completion time of work category (i), that is, the estimated work time T _i
When the signal S _i indicating the completion of the work of the work section (i) is generated at or before the elapsed time of, the next work section (i + 1) is calculated at the central speed controlled by the work section (i). ) The work is started, and if the work completion signal S _i does not occur even after the expected work time T _i elapses, a predetermined time interval is applied until the time elapsed work completion signal S _i is generated. The central part speed is controlled to be decelerated each time Δt elapses, and after the work completion signal S _i is generated, the central part speed immediately before that is maintained is maintained. Is the way.

(Operation) As described above, in the present invention, the expected stop work time T ₁ , ..., T _n is set for each work category (1) to (n) of the input / output side stop work, and each work category (1) to (n) is set. Each time i) is completed, a signal S _i indicating work completion is generated, and the actual elapsed time T ′ _i for each work category
And the expected work time T _i .

When T ′ _i ≦ T _i ; when the actual elapsed time T ′ _i is within the expected work time T _i (T ′ _i
≦ T _i ), that is, when the completion signal S _i is detected at or before the expected work time T _i elapsed time, the speed is maintained at the central speed V _i calculated in the previous work section (i). That is, the central speed of the work section (i + 1) until the start of work is controlled by V _{i + 1} = V _i . Here, the central velocity V _i (m / min) is calculated by the equation (1).

V _i = 60 L _A / (T _B + T _A ) ・ ・ ・ (1) where L _A : When the signal S _i indicating the start of work division (i), that is, the completion of work division (i-1) is detected Is the remaining effective storage amount of the strip device and is calculated by L _A = NA (where N = the number of strip turns in the storage device, A = the remaining effective travel distance of the strip storage device (m)).

T _B : Incoming and outgoing side remaining expected stop work time, which is calculated as the sum of the expected work time (T _i ) of the remaining work sections. For example, at the start of work in work category (i), T _B = T _{B (i)} = T _i + ... + T _n .

T _A : margin time for an unexpected situation in the final work category (n), which is set to an appropriate value according to the degree of difficulty of weldability, for example.

'In the case of _i> T _i: actual elapsed time T' T if _{the i} has exceeded the expected stop time T _i (T _'i
> T _i ), that is, when the completion signal S _i of the work section (i) is not detected even after the expected stop time T _i (seconds), the central speed V _i (at every predetermined time pitch Δt (second)) (m / min) is reduced by ΔV _i (m / min) calculated by the following equation to perform deceleration correction: However, V _i = 60 L _A / (T _B + T _A ) ... (1 ′), and in these formulas (1 ′) and (2), L _A : expected work time T _i of work category (i) Is the remaining effective storage amount of the strip storage device at the time when has elapsed, and is calculated simultaneously with the above case.

T _B : As described above. That is, T _B = T _{B (i + 1)} = T _{i + 1} + ... + T _n T _A : As described above.

Δt: correction time interval, which is set to an appropriate value such as 10 seconds or 20 seconds.

The deceleration correction according to the above formula (2) is completed in the work category (i),
That is, the process is repeated until the signal S _i is detected and superimposed on the previous correction.

This central speed control is carried out one after another in accordance with the input / output side work classification, and the central speed is automatically controlled in accordance with the low speed side. When the completion signal S _i is generated after the actual elapsed time T ′ _i exceeds the expected stop time T _i , the central speed V _i −ΣΔV _i in the deceleration state immediately before the generation is maintained.

(Example) Next, the present invention will be described by taking a pickling line for strips as an example.

FIG. 1 is a schematic explanatory view showing a pickling line 10, in which a line central part processing device 16 such as a pickling tank and a strip storage are provided in a line composed of a line inlet side part 12 and a line outlet side part 14. A device 18 is arranged. The storage device 18 is provided not only on the entrance side but also on the exit side.

The line entry side 12 is provided with a device for shearing the end of the strip from the pay-off reel and welding the strip.While these operations are performed, the strip on the entry side is stripped. Is stopped. On the other hand, at the line outlet portion 14, it is taken up by a coiler through a trimmer and a cutting shear. While these operations are being performed on the outlet side, the strip travel on the outlet side is stopped as described above.

In this way, the continuous processing line 10 such as the pickling device continues to operate even while the running of the strip on the inlet side and the outlet side 12 and 14 of the continuous line is stopped. Accordingly, the strip traveling speed in the continuous processing line 10, that is, the central speed is controlled while considering the capacity of the strip storage device 18.

Next, FIG. 2 is a graph illustrating a control system according to the present invention, and regarding a specific control example, the conventional method is shown by a broken line and the present invention is shown by a solid line. Input / output side work classification is n
It is classified into categories and the expected downtime of each work is T _i , ... + T _n . Work up to work classification (1) ~ (i-1 ) has completed work exactly as expected stop time, resulting in a delay to the actual elapsed time T _'i is expected to stop time T _i in the work category (i) In the conventional method, as shown by the broken line in the figure, the time point a _n
Until then, the center speed remains the same as in the previous step, and the center speed is corrected only when work section (i) is completed. Therefore, it is necessary to sudden deceleration correction as shown by the broken line in the work completion signal input point a _n.

On the other hand, in the present invention, the expected work time T _i of work category (i)
At the time point when Δt seconds have passed, the central velocity is corrected for the first time by a _{1 according} to the equation (2). Therefore, the center velocity V ¹ _i after the first correction is expressed by the following equation, where the velocity before correction is V ⁰ _i and the first correction amount is ΔV ⁰ _i : Since the speed correction is repeated by weighting every Δt seconds,
Central velocity V ^m _i in m-th correction time a _m is a V ^m-1 _i m
-1st corrected velocity, ΔV ^m-1 _i is calculated as the mth corrected amount by the following formula: In this way, since the central speed is corrected in steps every Δt seconds, the consumption length L of the remaining effective stop accumulated amount at the time of completion of work section (i) is smaller than that of the conventional method,
Central velocity V ⁰ i at the start of work in the next work segment (i + 1)
_{i + 1} is controlled at a higher speed than the conventional method. This reduces the change in center speed.

In the illustrated example, it is explained that the control is performed only in the work division (i) for convenience, but such control is performed in the work division (1).
To work division (n).

(Effects of the Invention) In the present invention, it is sufficient to consider only the time extension due to an unforeseen situation in the final work category (n) of stop, and the margin time T _A is set in consideration of the time extension due to an unexpected situation in the intermediate work category There is no need to set, and the maximum travel distance of the strip storage device can be utilized.

For this reason, in the conventional method, about 1/4 to 1/5 of the movable distance of the strip storage device was necessary as a margin distance for a shortage, but in the present invention, it should be about 1/10. The strip storage device can be made compact.

Furthermore, there is no rapid speed correction between work sections, and smooth running of the line is guaranteed.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view of a continuous pickling treatment line as an example of the continuous treatment line, and FIG. 2 is a diagram explaining a control system in the present invention based on a concrete example. 10: Pickling line 12: Line entrance side 14: Line exit side 16: Line center processing device 18: Strip storage device

Claims (1)

[Claims] 1. In a continuous strip processing line such as a pickling line equipped with a strip storage device, the input / output stop work in the continuous processing line is divided into a plurality of required work sections (1) to (n), Set the expected work time T _{1 to} T _n for each work category, and complete the work when the stopped work in each work category (i) (where i = 1, ..., n) is actually completed. Generating a signal S _i indicating that the expected work completion time of work category (i), that is, the expected work time T _i
When the signal S _i indicating the completion of the work of the work section (i) is generated before or after the elapsed time of, the next work section (i + 1) is operated at the central speed controlled by the work section (i). When the work is started and the work completion signal S _i is not generated even after the expected work time T _i has elapsed, a predetermined time pitch Δt is generated until the work completion signal S _i is generated after the time has elapsed. The central speed is controlled to be decelerated each time, and after the work completion signal S _i is generated,
An automatic central speed control method for continuous processing lines, characterized by maintaining the central speed immediately before the occurrence.