JP2001079605A - Method for cutting strip having different width - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the generation of projecting part in the inner turn or the outer turn of a coil in the case that operation for coiling into separate coils having different widths is executed by cutting a strip on the inlet side of coilers by cutting at a position on the narrow width side from a width changing point in the longitudinal direction of the strip. SOLUTION: A preceding strip S1 and succeeding strip S2 which are continuously rolled with a hot finishing mill 1 are cut in the vicinity of the width changing point b with a cutting machine 14, the preceding strip S1 is coiled into a coil 17 with the coiler 3 on the downstream side, the tip of the succeeding strip S2 after cutting is fed to a mandrel 9 from a pinch roll 7 for coiling and coiled with the coiler 2 on the upstream side. The width changing point b (joined point) between a preceding sheet bar and a succeeding sheet bar which are joined with a joining machine 20 is tracked on a line and, when the joined point reaches just under the cutting machine 14, cutting is executed. The error of this tracking is preliminarily determined and the sheet bar is cut at the point where is shifted by a length of not shorter than the error to the side of the narrow width from the width changing point.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for cutting different width strips in which the vicinity of different width points of continuously hot-rolled different width strips is cut by a cutting machine arranged on the entrance side of a winding machine. The leading strip and the trailing strip that have been cut are wound by a winder as separate coils having different widths.

[0002]

2. Description of the Related Art In recent years, in a hot rolling line, endless rolling in which a preceding sheet bar and a succeeding sheet bar are joined at the entry side of a finishing mill and a plurality of sheet bars are continuously finished and rolled has been commercialized. Have been. In a hot rolling line that performs endless rolling, as shown in FIG. 5, a plurality of winding machines 2 and 3 are provided downstream of the finishing mill 1.
Further, a cutting machine 14 is provided on the entry side of the upstream winding machine 2.

In this hot rolling line, a joining point between a preceding strip S1 and a succeeding strip S2 which have been continuously finish-rolled is cut by a cutting machine 14, and the plurality of winding machines 2, 3 are cut.
Then, an operation is performed in which the preceding strip S1 and the following strip S2 are wound alternately to form a plurality of coils. For example, in the endless rolling as described above, as disclosed in Japanese Patent Laid-Open No. 5-15903, it is also possible to join sheet bars having different widths on the entrance side of a finishing mill and perform continuous finish rolling. Have been done.

[0004] In this case, the width of the strip is different between the leading side and the succeeding side with respect to the joining point, and it is possible to continuously roll strips having different widths (hereinafter, referred to as "rolling").
A strip obtained by continuously rolling strips having different widths is referred to as a strip having a different width. ). And after the finish rolling, the different width point b
By cutting in the vicinity (that is, the joining point) and winding each of the preceding strip S1 and the following strip S2 around a coil, coils having different coil widths can be obtained. still,
In FIG. 5, reference numerals 9 and 10 denote mandrels of the winding machines 2 and 3, respectively, and reference numeral 13 denotes a pinch roll on the input side of the cutting machine 14,
Reference numeral 8 denotes a winding pinch roll of the winding machines 2 and 3, respectively.

[0005] A sizing press has been put to practical use in which a steel slab to be subjected to hot rolling is pressed in the width direction with a pair of left and right dies to adjust the width of the steel slab. If this sizing press is used, for example, as shown in FIG. 8, one steel piece 50 can be adjusted to a plurality of widths to obtain a steel piece having a different width point b. By hot rolling the slab having the different width point b, it is possible to produce strips having different widths by one finish rolling. Also in this case, the strip after the finish rolling is cut in the vicinity of the different width point to form a plurality of coils having different widths.

[0006]

By cutting the strip in the vicinity of the different width point as described above, when winding the continuously hot-rolled strip into a plurality of coils, the different width point is tracked on the rolling line. When the different width point reaches the cutting machine, the cutting machine is operated to cut the strip.

However, it is very difficult to accurately cut different width points based on tracking, and a certain degree of error cannot be avoided. For this reason, the cutting is usually performed at a position shifted to some extent in the longitudinal direction from the different width point. Here, when the cutting point is located on the wider side than the different width point in the longitudinal direction of the strip, when the strip on the narrow side is taken up as a coil, the outermost or innermost winding of the coil is wide. As a result, a protruding portion appears on the side surface.

For example, as shown in FIG. 5, a wide preceding strip S1 is taken up by an upstream take-up device 2, and then a narrow succeeding strip S2 continuously fed is taken up by a downstream one. When winding by the winding machine 3, different width points are cut by the cutting machine 14, but the cutting points always have errors as described above. Here, for example, it is assumed that the cutting point is shifted to the wide side in the strip longitudinal direction (that is, the preceding strip S1 side).

Then, the leading end of the trailing strip S2 after cutting has the same width as the (preceding) wide strip S1, so that the downstream winder 3 has a trailing end in which only the leading end has a wide width. The strip S2 is to be wound (in FIG. 5, the following strip S2 is wound by the winder 3 on the downstream side).
Is indicated by a broken line. ). Therefore, as shown in FIG. 6, a coil 17 is formed by winding the strip S2 into a coil.
Has a wide strip remaining on its innermost winding
In other words, the projection 15 is formed.

[0010] Here, the wound coil is pulled out of the mandrel after the winding is completed, and is caught by a transfer machine with a claw hooked on the inner diameter portion of the coil, and is conveyed to a coil storage place. Further, there is a case where it is transported by a conveyor in an up-end state. As shown in FIG.
When the coil 17 is lifted by the transfer machine 61 and the protrusion 15 is provided on the inner winding of the coil 17, the protrusion 15 of the inner winding may be deformed by the claw 60 of the transfer machine 61 when the coil 17 is lifted.
In the worst case, the nail 60 is disengaged and cannot be lifted.

Further, even when the coil is transported on the conveyor in the up-end state, there is a problem that the protrusion 15 is deformed by contact with the conveyor, causing ear damage.
The present invention solves the above-described problems, and continuously finish-rolls strips having different width points, cuts near the different width points on the entry side of the winding machine, and separately separates the wide coils and the narrow coils. An object of the present invention is to provide a method for cutting a strip having a different width which does not cause the above-mentioned protrusions when the winding operation is performed.

[0012]

SUMMARY OF THE INVENTION According to the present invention, a different width strip having different width points continuously rolled by a hot finish rolling mill is arranged downstream of the hot finishing mill near the different width point. A method for cutting a strip of different width, which is cut by a cutting machine according to the present invention, wherein the above-mentioned problem is solved by cutting a position on the narrower side than the different width point in the strip longitudinal direction.

In the method of cutting a different width strip, when tracking and cutting the different width point, an error of the tracking is obtained in advance, and a narrow width from the different width point by a length equal to or longer than the error is obtained. It has been found that it is preferable to cut a point shifted to the side.

[0014]

FIG. 1 is an overall schematic view showing an example of a hot rolling line suitable for carrying out the present invention. The hot rolling line shown in FIG. 1 is configured by arranging the following facilities in this order from the upstream side. A sizing press 40 capable of freely adjusting the width of a billet 50 such as a continuously cast billet to be rolled. Rough rolling mills 41, 42, 43 which roughly roll the steel slab whose width has been adjusted to a predetermined width by the sizing press device 40 to a sheet thickness capable of performing finish rolling to form a sheet bar 51. A joining device 20 for joining the tail end of the preceding sheet bar and the tip end of the following sheet bar. A hot finishing mill 1 in which seven rolling stands are connected in series. Pinch roll 13. Cutting machine 14. An upstream winder 2 and a downstream winder 3.

In addition, 7 is a pinch roll for winding the upstream winder 2, 8 is a pinch roll for winding the downstream winder, 9
Is a mandrel of the upstream winder 2, and 10 is a mandrel of the downstream winder 3. In the above-described line, it is possible to roll using a slab having a width adjusted to a predetermined width by the sizing press device 40, and to perform an operation of cutting at different width points.
An operation of joining the preceding sheet bar and the succeeding sheet bar with the joining device 20, performing continuous finish rolling, and cutting at different width points is also possible.

In FIG. 1, the leading strip S1 and the trailing strip S2, which have been continuously finish-rolled, are cut by the cutter 14 near the different width point b, and the leading strip S1 is separated from the downstream winder 3 by the cutting machine 14. The leading end of the subsequent strip S2 after cutting is fed into the mandrel 9 from the winding pinch roll 7 as shown by the broken line, and is wound by the upstream winding machine 2 as shown by the broken line. ing.

The different width point b (ie, the joining point) of the preceding sheet bar and the succeeding sheet bar joined by the joining device 20 is tracked on the line, and when the joining point arrives immediately below the cutting machine 14, Cutting is performed. Note that this different width point b
May be formed by the sizing press device 40 in some cases.
Hereinafter, details of this tracking will be described.

A different width point b, which is a joining point between the preceding sheet bar and the succeeding sheet bar joined by the joining device 20, is a detector arranged between the joining device 20 and the hot finishing mill 1. After passing through the position 30, the different width point is detected by the detector 30, a detection signal is sent to the host computer 31, and the detection time t is set in the host computer 31. The host computer 31 calculates the time at which the different width point passes the position of the cutting machine 14 from the detection time t of the different width point and the rolling conditions such as the rolling speed, and controls the cutting of the strip by the cutting machine 14. Sends a disconnection time command signal a to the control device 32. The flow for calculating the disconnection time command signal a will be described later.

At the cutting time, the control device 32
To cut the strip. In the example of FIG. 1, since the line is configured to perform cutting while the strip is pressed by the pinch roll 13 and the take-up pinch roll 7, the control device 32 controls the pinch roll 13 and the take-up pinch roll 7. An operation command for holding down the strip is output to 7 immediately before the cutting time.

Hereinafter, a case where the preceding sheet bar and the following sheet bar are joined by the joining device 20 and continuously rolled will be described as a first embodiment. The case where rolling is performed by providing different width points on a slab using a sizing press will be described as a second embodiment. In the first embodiment, a preceding sheet bar and a succeeding sheet bar having different widths are joined by a joining device 20, and hot finish rolling is continuously performed.

The width of the preceding sheet bar and the width of the succeeding sheet bar are W1 and W2, respectively. The preceding sheet bar is hot-finished and rolled into a preceding strip S1 having a width W1 '. Also,
The succeeding sheet bar is hot-finished and rolled continuously with the preceding sheet bar to form a succeeding strip S2 of width W2 '. The joining point between the preceding sheet bar and the succeeding sheet bar has a width of W1 to W
This is also a different width point b that changes to 2. The detector 30 has the different width point b
Is detected as a joining point, and a detection signal is sent to the host computer. The host computer 31 calculates a strip cutting time a in the cutting machine 14 from the detection signal and the like, and
Output to

Here, a method of calculating the cutting time a will be described.
This will be described according to the processing flow shown in FIG. First, a time t1 at which the different width point (that is, the joining point) passes through the cutting machine 14 is calculated based on the detection time t of the different width point and the information of the rolling conditions input in advance to the host computer (step 100). ).

Next, based on the rolling condition information previously input to the host computer, the width W1 of the preceding strip is obtained.
'And the width W2' of the following strip (step 1).
10) If the width W1 'of the preceding strip is larger than the width W2' of the succeeding strip, the process proceeds to step 120; otherwise, the process proceeds to step 130. In step 120, the cutting time a = t1 + α is calculated. Here, the value of α is a value based on the tracking error. That is, the value is set in advance in consideration of the difference between the position of the different width point recognized by the host computer and the position where the different width point actually exists.

On the other hand, at step 130, the cutting time a = t
1−α is calculated. The host computer tracks the position of the different width point at each time based on the detection time t obtained by using the detection signal of the different width point detected by the detector 30 as a trigger and a preset rolling condition. However, due to the error between the preset rolling conditions and the actual rolling conditions, etc., the recognized position of the different width point on the host computer does not exactly match the actual position of the different width point. Error occurs.

However, the error of the recognition position of the different width point is as follows.
From experience, you can know in advance. Therefore, the time α corresponding to the error may be set in the host computer in advance, and the cutting time may be corrected. Thus, the cutting time a corrected in step 120 or step 130 is set in the control device 32 of the cutting machine 14 (step 140
).

According to the calculation method of the cutting point described above, the cutting point can always be on the narrower side than the different width point position in the strip longitudinal direction. For example, as shown in FIG. 3, each width is W2 '>W1' = W3.
′, Three strips S 1, S 2, S 3 are joined and rolled continuously in this order.

In this case, according to the flow of FIG. 2, first, the vicinity of the different width point b1, which is the joining point between the preceding strip S1 and the following strip S2, is set as a cutting point, and the width of the preceding strip S1 is changed to the following strip. Since it is smaller than the width of S2, the calculation of the cutting time a is performed in step 130,
Cutting is performed earlier by a time than the time when the different width point b1 (that is, the joining point) passes through the cutting machine 14.

Since the time α is set to a value equal to or longer than the time corresponding to the tracking error in the host computer, when the tracking is shifted to the wide side (ie, the strip S2 side) from the position of the different width point b1. However, as shown in FIG. 3, the cutting point C1 can always be located on the narrower side (that is, on the strip S1 side) than the different width point b1.

Next, the cutting time of the different width point b2, which is the joining point of the strip S2 and the strip S3, is determined by setting the width of the preceding strip S2 to the following strip.
Since it is larger than the width of S3, it is determined by step 120, and the cutting is executed by α time later than the time when the different width point b2 passes through the cutting machine. Therefore, even if the tracking is shifted to the wider side (that is, the strip S2 side) than the different width point b2 position, as shown in FIG. 3, the cutting point C2 is narrower than the different width point b2 position (that is, , Strip S3 side).

The cutting is performed as described above,
When S1, the strip S2, and the strip S3 are respectively wound around the coil, as shown in FIG. 4, the different width point b1 becomes the inner winding of the coil of the strip S2, and the different width point b2 becomes the outer winding of the coil of the strip S2. Will be located. So strip
A coil outer winding of a strip S1 having a coil width smaller than S2,
The wide strip does not remain in any of the coil inner windings of the strip S3 having a smaller coil width than the strip S2, and no protrusion is generated.

Next, a second embodiment of the present invention will be described. In the second embodiment of the present invention, in the hot rolling line shown in FIG. 1, first, one slab is adjusted to a plurality of widths by the sizing press device 40. That is, using a sizing press device 40, for example, a billet having at least one or more different width points b as shown in FIG.
Perform 50 processes. In addition, the sizing press device is a device that adjusts the width of the slab by reciprocating a pair of dies arranged so as to face both width end sides of the slab and pressing the slab from the left and right. Is a known device.

The steel slab 50 having the different width point b processed by the sizing press 40 is roughly rolled by the rough rolling mills 41, 42, and 43 to form a sheet bar 51 having the different width point b. (See FIG. 1). In this case, this sheet bar is
At the entry side of the hot finishing mill 1, the different width point b is detected by the detector 30 and the host computer cuts off based on the detection time t. The setting of the cutting time a in the control device 32 of the machine 14 is the same as in the first embodiment described above.
The calculation flow of the disconnection time a is the same as that in the first embodiment.

A feature of the second embodiment is that a plurality of coils having different widths can be manufactured from one steel slab. In this case, by applying the present invention, a protrusion is formed on the end face of the coil. There is nothing. As described above, according to the first embodiment and the second embodiment described above, the strips having different widths are continuously finish-rolled, and the vicinity of the different width point is cut at the entry side of the winding machine to obtain the width. Even when the coils are wound around different coils, no projecting portion is formed on the inner or outer winding of the coil.

[0034] In the first embodiment,
The sizing press 40 is not necessarily required because the joining device 20 joins sheet bars of different widths to form different width points. In the second embodiment, since the sizing press device 40 processes one steel slab into steel slabs having a plurality of widths to form different width points, the joining device 20 is not necessarily required.

Further, in the above embodiments,
The different width point is detected by the detector 30 on the entrance side of the finishing mill, and tracking of the different width point is performed based on the detection time.However, the present invention is not limited to this. The different width point may be detected using a detector arranged on the downstream side. Further, for example, in the case of the first embodiment, the different width point may be tracked based on the joining completion time in the joining device 20, the transfer conditions after the joining, the rolling conditions, and the like.

Further, in the case of the second embodiment, the different width point is determined based on the time for changing the condition of the width press performed for forming the different width point in the sizing press device 40 and the subsequent transfer conditions, rolling conditions, and the like. You may specify and track. Further, in the above-described embodiment, two down coilers are arranged as winding machines so as to alternately wind the preceding strip and the succeeding strip, but one carousel reel may be arranged. Good.

[0037]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In a hot rolling line shown in FIG. 1, sheet bars having different width points are manufactured by using a sizing press or a joining device, and the bar is continuously subjected to finish rolling. An operation was performed in which the vicinity of the different width point was cut and wound around separate coils having different widths.

In the example of the present invention, either a sizing press device or a joining device is applied and finish rolling is performed.
When the width difference between the preceding strip and the succeeding strip at the different width point exceeds 100 mm, the cutting method of the different width strip of the present invention was applied. The coil after winding was transported to a coil storage using a transfer machine. On the other hand, in the conventional example, the correction of the tracking error is not performed, and the coil of the different width is cut while keeping the tracking information.

As a result of the above-mentioned operation, in the conventional example, the occurrence rate of ear damage was 50% with respect to the total rolling number of the different width materials (including the preceding material and the succeeding material). On the other hand, in the case of the example of the present invention, no ear damage occurred in the wound coil, and the ear damage occurrence rate was 0%. In the conventional example, transfer abnormalities that make it impossible to lift the coil occurred about 10% of the total number of transfers of the coil of different width rolled material (including the preceding material and the succeeding material). After the application of the invention, it could be 0%.

[0040]

According to the present invention, the different width strips are continuously finish-rolled, and the vicinity of the different width points of the rolled different width strips is cut at the entry side of the winder and wound into separate coils having different widths. In operation, it was possible to eliminate the occurrence of a projecting portion in the inner or outer winding of the coil.

Therefore, after the strip is wound on the coil, there is no occurrence of a transfer error in which the coil cannot be transferred when the coil is lifted and transferred by the transfer machine, and the coil is not damaged by ears. lost. Further, when the coils were transported while being placed on the conveyor in an up-end manner, there was no occurrence of ear pain trouble.

[Brief description of the drawings]

FIG. 1 is an overall schematic diagram of a hot rolling line to which the present invention is applied.

FIG. 2 is a flowchart illustrating a cutting method according to the present invention.

FIG. 3 is a schematic view of a strip having different widths joined at the front and rear ends to which the present invention is applied.

FIG. 4 is a perspective view of a coil when the cutting method of the present invention is applied.

FIG. 5 is a perspective view of a main part of a line for explaining cutting of a conventional different width strip.

FIG. 6 is a perspective view illustrating a coil winding shape when a conventional different-width strip is cut.

FIG. 7 is a schematic diagram illustrating a problem that occurs when a conventional coil is lifted by a transfer machine.

FIG. 8 is a perspective view of a billet having different width points.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hot finishing mill 2 Upstream winder 3 Downstream winder 7 Winding pinch roll (of upstream winder) 8 Winding pinch roll (of downstream winder) 9, 10 Mandrel 13 Pinch roll 14 Cutting machine 15 Projecting part 16 Coil end face 17 Coil 20 Joining device 30 (Different width point) detector 31 Computing unit 32 Control unit 40 Sizing press unit 41, 42, 43 Rough rolling mill 50 Steel slab 51 Sheet bar 60 Claw 61 Transfer machine S1 Leading strip S2 Trailing strip b, b1, b2 Different width point C1, C2 Cutting part W1, W2, W3 Billet (sheet bar) width W1 ', W2', W3 'Strip width

Claims (2)

[Claims] 1. A different width for cutting a different width strip having different width points continuously rolled by a hot finishing mill by a cutting machine arranged downstream of the hot finishing mill near the different width point. A method for cutting a strip, wherein a position on a narrower side than the different width point is cut in a longitudinal direction of the strip. 2. In tracking and cutting the different width point, an error of the tracking is obtained in advance,
2. The method for cutting a different width strip according to claim 1, wherein a point shifted from the different width point to a narrower side by a length longer than the error is cut.