JPH0472915B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for automatically controlling the speed of the central portion of a continuous processing line, such as a continuous pickling line for strip (thin steel sheets), when the input and output sides are stopped. .

(Prior art) Generally, in a continuous strip processing line,
Coil connection work by welding etc. on the line inlet side and coil division work on the line outlet side make it possible to
The strip stops on the exit side. For this reason, a strip storage device is installed at the input and output sides of the central processing section, and this strip storage device temporarily stores the strip and stops the strip from running in the central part of the continuous processing line even when the input and output sides are stopped. Operate continuously without any trouble.

The amount of strip that can be stored in the strip storage device is usually determined depending on the downtime during the input and output operations, and this downtime varies depending on the condition of the material and the skill level of the workers. Therefore, the central speed is usually controlled depending on the progress of the work and the amount of storage in the storage device.

As a method of controlling the speed of the central part of the strip in such a continuous processing line,
There is a method proposed in No. 5991. This control method is used when the preset work classification is completed.
At each point in time when a completion signal is detected, the ``remaining expected stop time'' of the input/output side and the ``remaining effective time'' calculated according to the storage amount of the strip storage device at that time are calculated, and the two are compared. However, the center speed is corrected so that the difference between the expected remaining time and the remaining effective time becomes zero.

However, with this control method, if an unforeseen situation such as devaluation of a defective part of a strip occurs in a preset work category and the work is delayed, the work in that work category will continue even after the expected stoppage time has elapsed. No signal indicating completion is detected. Therefore, at this point, the center speed is not corrected and is maintained at the high level of the previous stage.

Therefore, by the time a signal indicating the completion of the work in that work category is detected, the remaining effective strip storage amount has significantly decreased, and the center speed must be rapidly decelerated and corrected. In extreme cases, it may be necessary to stop running the strip in the center.

In order to eliminate this inconvenience, it is necessary to assume these unexpected situations and set a large margin for the travel distance for the storage amount of strips, and to lengthen the storage amount of the strip storage device. There are problems such as increasing costs and making maintenance difficult.

Therefore, the inventors of the present invention have repeatedly studied to develop a system with good responsiveness that avoids sudden speed corrections, and have developed a system that can delay the completion of each work category and provide a signal indicating work completion even after the target completion time has elapsed. It has been found that if this does not occur, the speed control can be performed smoothly by correcting the center speed at predetermined short intervals after the target completion time has elapsed and updating the control speed each time. The applicant has already filed this patent application.
It is proposed as No. 62-176577.

The gist of the patent application is as follows: In a continuous strip processing line such as a pickling line equipped with a strip storage device, (a) inlet and outlet stop operations in the continuous processing line are performed in multiple ways; Divide into required work categories (1) to (n), and calculate the target work time T ₁ for each of the required work categories.
(b) Generating a signal S _i indicating work completion at the time when the stop work in each work category (i) (where _i = 1, ..., n) is actually completed; (c) If a signal S _i indicating the completion of work in work class (i) is generated at or before the target work completion time of work class (i), that is, at the elapsed time of the expected work time T _i , work class ( (d) When the work completion signal S _i is not generated even after the target work time T _i has elapsed. After the elapse of the time period until the work completion signal S _i is generated, the central portion speed is controlled to decelerate every time the predetermined time pitch Δt elapses;
After the work completion signal S _i is generated, the speed of the center section immediately before the generation is maintained. A method for automatically controlling the speed of the center section of a continuous processing line, characterized by the steps (a) to (d) above.

In this way, in the patent application, the target stopping work time T ₁ , ..., T _o is set for each work classification (1) to (n) of the entry/exit side stopping work, and each work classification (i) A signal S _i indicating work completion is generated each time the target work time T _i has elapsed, and if the signal S _i is not generated even after the target work time T i has elapsed, the center speed is decelerated and corrected at every time interval Δt. .

By the way, in the method proposed in this patent application, (d)
When calculating the center speed deceleration correction amount ΔV _i for every Δt seconds in the process of , no matter how _many times the correction is repeated, the strip storage device is Effective storage amount
L _A is used as the basis.

However, the effective storage amount changes over time. Therefore, the deceleration correction amount ΔV _i for each Δt calculated based on the effective storage amount at the time when the target working time T _i has elapsed may no longer reflect subsequent changes in the situation while the correction is repeated.

For example, when stopping operations are performed simultaneously on the entry and exit sides, the actual center speed is controlled in accordance with the calculated speed on the lower speed side. Therefore, the effective storage amount on the high speed side is larger than necessary. Enter after this
When the magnitude of the central calculation speed on the exit side is reversed (that is, the low speed side and the high speed side are reversed), the central part speed becomes the calculation speed of the side that was on the high speed side until the very beginning, which has become the new low speed side. Therefore, the effective storage amount during this period is not reflected in the control of the central speed. In other words, the center speed is controlled at a lower speed than necessary.

(Problems to be Solved by the Invention) Therefore, an object of the present invention is to further improve the method proposed in the above-mentioned patent application, and to continuously control the center speed to an optimum value in response to changes in the situation. An object of the present invention is to provide a method for automatically controlling the speed of a central section of a processing line.

(Means for Solving the Problems) In order to achieve this objective, the present inventors have conducted extensive research, and have used this method as a basis for calculation of input/output side correction of the center speed every Δt seconds after the target working time T _i has elapsed. We have come up with the idea that by using the input and output effective storage amounts at the time when the correction calculation is performed, the center speed can be controlled to the optimal amount depending on the situation at that time.

Thus, 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) inlet/outlet stop operations in the continuous processing line are divided into a plurality of necessary work categories (1) ) to (n), and for each work category, the target work time T ₁
(b) Generating a signal S _i indicating work completion at the time when the stop work in each work category (i) (where _i = 1, ..., n) is actually completed; (c) Work classification (i) (however, i = 1, ..., n-1)
If the signal S _i indicating the completion of the work of the work category (i) is generated at or before the target work completion time of the target work time T _i , the work category
Starting work in the next work section (i+1) at the same speed as the central speed V _i calculated in (i), (d) Work section (i) (where i=1, ..., n- 1)
If the work completion signal S _i is not generated even after the target work time T _i has elapsed, the operation is performed every time the predetermined time pitch Δt elapses until the work completion signal S _i is generated after the time elapses. The remaining effective storage amount L _A of the strip storage device is actually measured, and at each time pitch Δt, the measured remaining effective storage amount L _A , remaining target working time T _B , and final work division (n) are calculated. This automatic central speed control method for a continuous processing line is characterized by the steps (a) to (d) above, including calculating the central speed from the margin time _TA for unexpected situations and performing deceleration control.

(Function) In this way, in the present invention, the target work time T ₁ to _{T o} is set for each of the entry/exit side stop work classifications (1) to (n), and the A signal _{S i} indicating work _completion is generated at to correct.

Next, the actual elapsed time T′ _i is divided into cases where the actual elapsed time T′ i is within the target working time T _i (T′ _i ≦T _i ) and cases where the actual elapsed time T′ i exceeds the target working time T _i (T′ _i > T _i ). The operation in this case will be explained.

If the signal S _i occurs within the target working time: T′ _i ≦
T _i If the actual elapsed time T′ _i is within the target working time (T′ _i ≦T _i ), that is, if the completion signal S _i is detected at or before the expected working time T _i elapsed time, then the previous The speed is maintained at the center speed V _i calculated in work section (i) (where i=1, . . . , n-1). That is, the center speed V _i+1 =V _i at the start of work in work section (i+1) is controlled by V _i+1 =V _i .
Here, the center speed V _i (m/min) is calculated by the following equation (1): V ^o _i = (60L ^o _A −V _nio ×T _A )/T _B(i) ... …(1) Here, L _A : Start of work division (i), that is, work division (i)
−1) is the remaining effective storage amount of the stripping device when it detects the signal S _i-1 indicating the completion of step 1), and L ^o _A =
It is calculated by NA (where N=number of strip turns in the storage device, A=remaining effective travel distance of the strip storage device (m)).

T _B : Remaining target stoppage time for entry and exit sides,
It is calculated as the sum of the target work time T _i of the remaining work categories. The period from the start of work to the end of work time for work category (i) is determined as T _B = T _B (i) = T _i + T _i+1 +...+T _o .

T _A : Surplus time for unforeseen circumstances in the final work category (n), and is set to an appropriate value depending on, for example, the difficulty level of welding.

V _nio : Minimum central velocity (constant) determined from equipment constraints and steel plate quality.

If signal S _i is not generated when the target work time has elapsed:
T′ _i > T _i If the actual elapsed time T′ _i exceeds the target work time T _i (T′ _i > T _i ), that is, even if the target work time T _i (seconds) has elapsed, the work category (i ), if the completion signal S _i of ) is not detected, the effective storage amount L _A of the strip storage device is fetched every predetermined time interval Δt seconds, and m.
The center velocity V ^m _i (m/
min) using the following formula (where i=1,...
..., n-1): V ^m _i = (60L ^m _A −V _nio ×T _A )/T _B(i+1) ...(2) where, L ^m _A : Target for work category (i) Remaining effective storage amount of the strip storage device after m·Δt seconds have elapsed from the working time T _i seconds (here, Δt is the correction time interval, set to an appropriate value such as 10 seconds, 20 seconds, etc.) . L ^m _A = NA (where N = number of strip turns in the storage device, A = remaining effective distance of the strip storage device (m)).

T _B(i+1) : Remaining target work time for entry and exit sides,
It is calculated as the sum of the target work time for the remaining work categories. For example, if the target work time T _i of work category (i) is exceeded, it is determined as T _{B (i+1)} = T _{i +1} +...+T _o .

T _A , V _nio : As mentioned above.

The deceleration correction according to equation (2) above is repeated until the work in work category (i) is completed, that is, until the signal S _i is detected.

If the signal S _i is detected after deceleration correction is repeated every Δt seconds, the speed correction is performed using equation (2) at the time the signal S _i is detected, that is, at the end of the actual working time T′ _i . . That is, at this point V ⁿ _i =
The speed of the central part is controlled by V ^o _i+1 .

It is preferable that this central part speed control is carried out separately according to the entry and exit work divisions, and that the central part speed is automatically controlled in accordance with the calculation speed on the low speed side.

In addition, in the final work category (n), the slack time T _A
is set, it is not necessarily necessary to perform deceleration correction every Δt seconds as described above. Even after the target working time T _o has elapsed, the center speed can be maintained at the previous speed, and the speed can be returned to the standard center speed when the signal S _o is detected. However, in the final section (n), it is also possible to perform deceleration correction every Δt seconds as in the case of the above-mentioned work sections (1) to (n-1).

(Example) Next, the present invention will be explained using a strip pickling treatment line as an example.

Configuration of Processing Line FIG. 1 is a schematic side view showing the pickling line 10. Between the line inlet side 12 and line outlet side 14, there is a line central processing device 1 such as a pickling tank.
6 is provided, with strip storage devices 18, 20 arranged on its inlet and outlet sides.

The line entry side 12 is equipped with a device for shearing and welding the ends of the strip from the payoff reel. Also, the running of the strip at the upstream entry side 12 is stopped.

On the other hand, the strip at the line outlet side 14 passes through a trimmer and cutting shear and is wound up by a coiler. While these operations are being performed on the line outlet side, the strip running in the outlet section 14 downstream of the outlet storage device 20 is stopped.

In this way, the input side and output side 1 of the continuous processing line
Even while the running of the strip is stopped at 2 and 14, the central processing unit 10, such as the pickling device, continues to operate. When the input/output strips are stopped, the central processing unit 1 is stored in accordance with the remaining effective storage amount of the strip storage devices 18, 20 according to the stop period.
It controls the strip running speed at zero, that is, the center speed.

Control of Center Speed FIG. 2 is a graph illustrating an example of the calculated value of the center speed using the center speed control method according to the present invention. Regarding the specific example of speed (solid line),
It is shown in comparison with a conventional example (broken line). The illustrated conventional example is based on the method proposed in the above-mentioned Japanese Patent Publication No. 59-5991 (i.e., stopping work is divided into work categories (1) to (n)).
The speed is corrected at the completion of each work division (i), but the correction is performed only once after the completion of each work division (i).

Although FIG. 2 only shows the center speed V ⁱⁿ calculated based on the entry side stopping operation, the center area speed V ^out calculated based on the exit side stopping operation is also determined in exactly the same way. In FIG. 2, symbols indicating the center speed, such as _Vi , indicate the center speed calculation value determined based on the entry side stopping work in the entry side work section (i). That is, V _i
= V ⁱⁿ _i . The actual center speed control value V is V ⁱⁿ
It is given by the smaller value of and V ^out : V=min {V ⁱⁿ , V ^out } Here, only the calculation of the center speed based on the inlet side will be described. The same applies to calculations based on the output side.

The entire entry side stop work is divided into n work sections (1) to (n), and a target work time T _i is set for each work section (i) (i=1, . . . , n). The actual working time T′ _i of each work category (i) is within the target working time T _i (T′ _i ≦
T _i ) may exceed this (T' _i > T _i ), but in this case, each work in work categories (1) to (i-1) has its own target work time T ₁ to _{T i -1} , and there is a delay in the target work time T _i only after reaching work category (i) (where i = 1, . . . , n-1).

After the target work time T _i of work category (i) has elapsed,
The center speed is repeatedly calculated every Δt seconds (for example, 10 seconds) using the above equation (2) until the time a _o when work division (i) is completed. Therefore, Δt from the time when the target working time T _i has elapsed
The central velocity calculation values V ¹ _i , V ² _i , . . . , V ^m _i after the elapse of seconds, 2Δt seconds, . It is the optimal value at each time point that accurately reflects the amount L _A.

Assume that the completion signal _{S i is} detected at a time a _o which is mΔt+Δt′ seconds after the target work time T i has elapsed (Δt′≦Δt). At this point _ao , the center speed is calculated using equation (2) above. The center V speed V ^o _i+1 calculated at the time a _o when this signal S _i is detected accurately reflects the effective remaining storage amount L _A at the time a _o ,
This is used as the center speed calculation value in the next work section (i+1).

In the illustrated example, for convenience, the case where control is performed only in work division (i) is explained, but speed calculation and control are performed continuously from work division (1) to work division (n).

(Effects of the Invention) The effects of the invention will first be explained with reference to the specific example shown in FIG.

In the conventional method shown in FIG. 2, speed correction is not performed until the work classification is completed even if the target work time has elapsed. Therefore, a sudden correction as shown by the dashed line is required at time _ao .

On the other hand, in the present invention, after the target working time has elapsed, the center speed is corrected stepwise every Δt seconds to the optimum value according to the effective storage amount _LA remaining in the strip at each point in time.

The present invention is based on the above patent application (Japanese Patent Application No. 62-176577).
Compared to the method proposed in the previous issue, the speed correction every Δt seconds reduces the remaining effective storage amount at the time of correction.
It is excellent in accurately reflecting _LA .

Therefore, the present invention has the following effects: It is only necessary to consider the time extension due to unforeseen circumstances in the final work division (n) when the work is stopped, and there is no allowance for time extension due to unforeseen circumstances in the intermediate work divisions. time
It is no longer necessary to set T _A , and the movable distance of the strip storage device can be utilized to the maximum, improving production efficiency by 30 to 50% compared to the conventional method.

Rapid speed correction between work sections is eliminated, ensuring smooth running of the line.

[Brief explanation of the drawing]

FIG. 1 is a schematic explanatory diagram of a continuous pickling treatment line as an example of a continuous treatment line; and FIG. 2 is a graph showing a specific example of the center speed according to the control method according to the present invention in comparison with a conventional example. be. 10: Pickling line, 12: Line entry side, 1
4: line outlet side, 16: line central processing device, 18, 20: strip storage device.

Claims (1)

[Scope of Claims] 1. In a continuous strip processing line such as a pickling line equipped with a strip storage device, (a) Input/output stop operations in the continuous processing line are performed in a plurality of required work categories (1) to ( n), and for each of the work divisions, the target work time T ₁
(b) Generating a signal S _i indicating work completion at the time when the stop work in each work category (i) (where _i = 1, ..., n) is actually completed; (c) Work classification (i) (however, i = 1, ..., n-1)
If the signal S _i indicating the completion of the work of the work category (i) is generated at or before the target work completion time of the target work time T _i , the work category
Starting work in the next work section (i + 1) at the same speed as the central speed V _i calculated in (i), (d) Work section (i) (where i = 1, ..., n- 1)
If the work completion signal _{S i is} not generated even after the target work time T i has elapsed, every time the predetermined time pitch Δt elapses, after the time elapses until the work completion signal S _i is generated. The remaining effective storage amount L _A of the strip storage device is actually measured, and for each time pitch Δt, the measured remaining effective storage amount L _A , remaining target working time T _B , and final work division (n) are calculated. A method for automatically controlling the speed of a central portion of a continuous processing line, characterized in that the speed of the central portion is calculated from a margin time T _A for unexpected situations and deceleration control is performed. 2. If the work classification and target work time for stopping work on the entry and exit sides are set separately, and stopping work is performed on the entry and exit sides at the same time, the central part calculation speed on the low-speed side is adjusted. 2. The automatic central speed control method for a continuous processing line according to claim 1, wherein the speed is controlled.