JPH07290131A - Strip tracking method on hot run table - Google Patents

Abstract

PURPOSE:To improve accuracy in strip tracking on a hot run table. CONSTITUTION:Each table roller 5 comprising a hot run table is individually driven by each driving motor. In addition, a driving current value of the driving motor can be supplied to a controller 6. The driving current value of each table roller 5 is constantly checked in the controller 6; and if a current change above a prescribed threshold value is detected, a prescribed load is generated in the corresponding table roller 5; namely, it is recognized by the controller as the tip end part of a strip 7 has passed. Then, the operational timing of a calculation control such as starting time for coiling a strip 7 is decided by the controller 6 through a well-known means based on tracking information.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of tracking a strip moving along a rolling line in a hot rolling process, and more particularly to a method of tracking a strip running on a hot run table.

[0002]

2. Description of the Related Art In a hot rolling operation, it has been conventionally practiced to track a strip moving along a rolling line in order to determine the operation timing of calculation control such as winding start time and rolling start time. . Conventionally, as a method of tracking a strip traveling on a hot run table, for example, as shown in FIG. 3, a plurality of HMs are arranged along a hot run table 30 on a rolling line.
D31 (heat piece detector) is arranged and the strip 33
The leading end portion of FIG. 2 performs tracking by detecting the passing time of each HMD 31 installation position, and estimates the position of the strip 33 on the hot run table 30 from the mill speed of the finishing mill final stand 32.

As shown in FIG. 4, each HMD 31 outputs an ON signal when the tip of the strip 33 passes the HMD 31 installation position, and outputs the ON signal until the HMD 31 installation position passes. Track by doing.

[0004]

HMD3 as described above
In the tracking method using 1, the tracking pitch is determined by the installation interval of the HMD 31, and normally only about two units are installed, so the tracking pitch is wide. Therefore, in order to improve the tracking accuracy, it is necessary to significantly increase the number of HMDs 31 installed.

When the number of HMDs 31 is increased, the equipment installed along the hot run table 30 is increased and the maintenance load is increased. On the other hand, when the speed of the finishing mill final stand 32 is used, the strip 3
It is good if the finishing mill has the strip 33 when 3 is wrapped around the coiler 34, but when the strip length is short like a thick material and the total length is completely on the hot line, the strip 33 is Tracking accuracy deteriorates because the running speed is unknown. In this case, even if the traveling speed of the strip 33 is estimated by the table roller speed, high accuracy cannot be obtained due to slip between the roller and the strip.

The present invention has been made in view of the above problems, and an object thereof is to improve the accuracy of strip tracking on a hot run table.

[0007]

In order to achieve the above object, a strip tracking method for a hot run table according to the present invention is a method for tracking a strip running on the hot run table. It is characterized in that the position of the strip is detected by detecting the change in the drive current of the table roller.

[0008]

When the tip of the strip advances on each table roller, a load is input from the strip to the table roller, and the drive current of the table roller increases. By reading this change in current, it is recognized that the strip front end has passed each table roller position.

Further, when the tail end of the strip comes out of each table roller, the load on the table roller from the strip disappears and the drive current of the table roller decreases. By reading this current change, it is recognized that the strip tail end has passed each table roller position. As a result, tracking points are set by the number of rollers, and tracking accuracy is improved.

Further, since the current value of the roller is only read in spite of a large increase in the number of tracking points, it is not necessary to install many tracking detectors such as HMD along the hot run table, and Maintenance is not a burden.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS This embodiment will be described with reference to the drawings. First, the structure will be described. As shown in FIG. 1, a hot run table 2 is arranged on the downstream side of the final stand 1 of the finishing mill along the rolling line, and a pinch roll 3 is provided downstream of the hot run table 2. A winding device 4 is provided.

Each table roller 5 constituting the hot run table 2 is driven by each drive motor (not shown). Then, the drive current value of the drive motor can be supplied to the controller 6. In the controller 6, the drive current value of each table roller 5 is constantly checked, and when a current change of a predetermined threshold value or more is detected, a predetermined load is generated on the corresponding table roller 5,
That is, it is recognized that the leading end of the strip 7 has passed.

Further, the moving speed of the strip 7 is estimated from the above detection times and the intervals between the table rollers 5. Then, the controller 6 determines the operation timing of calculation control such as the winding start time of the strip 7 by a known means based on the tracking information.

In the above-mentioned structure, the strip 7 that has passed through the final stand 1 of the finishing mill is conveyed to the hot run table 2, and when the tip of the strip 7 sequentially passes over each table roller 5, each table roller. 5, a load is applied in order, and as shown in FIG. 2, the current value of each table roller 5 changes so as to rise for a moment. Subsequently, until the tail end of the strip 7 passes over the roller 5, a predetermined load is applied from the strip 7 and the state where the current value is high is maintained. Then, when the tail end of the strip 7 comes off, the load disappears and the current value changes downward.

Here, in FIG. 2, T _n indicates the current change time when the strip leading end of the nth table roller passes, and the leading end of the strip 7 reaches the fifth table roller 5. The state is shown. The controller 6 constantly checks the current value of each table roller 5, and when the current value changes to a predetermined threshold value or more, the corresponding table roller 5 position is stripped 7 at the current change times T _{1 to} T _5. The tip of the is considered to have passed.

By performing this for the drive current value of each table roller 5, tracking is performed at roller pitch intervals. At the same time, the moving speed of the strip 7 is estimated by the following formula. Here, S represents the roller span between the (n-1) th table roller 5 and the nth table roller 5, and T _n is the strip 7 of the nth table roller 5.
It represents the time when the tip passed.

As described above, in this embodiment, as many tracking points as the number of rollers of the hot run table 2 can be set, so that the tracking points can be set significantly more than in the conventional case, and the tracking accuracy is improved. In particular,
For a strip 7 having a short strip length such as a thick material, when the rear end portion is discharged from the finishing mill final stand 1 or is located between installed HMDs, the mill speed and HMD can be detected. Even if the position of the strip 7 cannot be estimated from the value, the position and moving speed of the strip 7 can be accurately estimated.

Further, even if the tracking points are greatly increased as described above, it is not necessary to arrange detectors such as HMDs along the hot run table 2, and the burden on equipment and maintenance does not become so large. In addition, in the above-mentioned embodiment, it is described that the tracking is performed by all the table rollers 5, but it is not always necessary to perform the tracking by all the table rollers 5.
Tracking may be done every other time.

Further, in the above embodiment, it is described that the tracking is carried out only by the change of the drive current value from the table roller 5, but the conventional tracking method using the tracking detector such as HMD is used. You may use together. Further, in the above-described embodiment, the explanation has been made such that the drive current of the drive motor that drives the table roller 5 is checked, but the drive current value may be measured at the power source position that supplies power to the drive motor. .

Further, in the above-mentioned embodiment, it is explained that only the leading end of the strip is tracked.
Of course, tracking may also be performed on the tail end of the strip by changing the current.

[0021]

As described above, according to the strip tracking method for the hot run table of the present invention,
The tracking point can be set significantly more than before, and the tracking accuracy can be improved. In particular,
The present invention is effective for short strips such as thick ones, and even if the strip is located at a position that cannot be estimated from the HMD or the mill speed, the tracking point can be set in roller pitch units in the present invention.
It is possible to recognize the position of the strip.

Further, even if a large number of tracking points are set as described above, the HM is set along the hot run table.
Since it is not necessary to arrange a large number of detectors such as D, it is possible to prevent the burden on equipment and maintenance from increasing.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram for explaining a strip tracking method in a hot run table according to an embodiment of the present invention.

FIG. 2 is a diagram showing a change in drive current in a strip tracking method for a hot run table according to an embodiment of the present invention.

FIG. 3 is a schematic configuration diagram for explaining a strip tracking method in a conventional hot run table.

FIG. 4 is a diagram showing an on / off state at the time of detecting the strip front end by the HMD.

[Explanation of symbols]

 2 Hot run table 5 Table roller 6 Controller

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location B21B 37/00

Claims (1)

[Claims] 1. A method for tracking a strip running on a hot run table, wherein the position of the strip is detected by detecting a change in drive current of each table roller that constitutes the hot run table. Strip tracking method in.