JPH08103810A - Hot continuous finishing mill having meandering prevention function - Google Patents

Abstract

PURPOSE: To prevent tail of rolled stock from meandering by controlling a drive device based on the meandering quantity measured by a meandering measurement means and adjusting pressing force of each small roll. CONSTITUTION: When the tip of a rolled stock 1 passes a rolling roll 2b, coiling of a rolled stock 1 is started by a down coiler 4, a looper 5 is elected. Further, after the rolled stock 1 passes the rolling roll 2b, an upper side press roll 6 and lower side press roll are moved in the rolled stock width center direction by a drive device 10. Further, the upper press roll 6 divided into small rolls 6a, 6b and lower side press roll 7 is moved in the rolled stock thickness direction to clamp/press the rolled stock 1 in up/down directions. In this way, offcenter for the press rolls 6, 7 is not generated, because a barrel length of roll is short, its rigidity is high and a gap between the press rolls 6, 7 is not changed in thickness direction, a rate of generating of meandering is significantly reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot continuous finish rolling machine having a meandering preventing function capable of preventing narrowing due to meandering of a trailing end of a rolled material in hot continuous finish rolling, and more particularly to a hot rolling finish rolling mill. The present invention relates to a hot continuous finish rolling mill having a meandering prevention function for preventing meandering.

[0002]

2. Description of the Related Art Conventionally, for finish rolling of hot rolled material,
A hot continuous finishing mill is widely used. Such a hot continuous finish rolling mill is usually a multi-stage stand rolling mill,
That is, it is composed of a plurality of stages of rolling stands, and sufficient finishing rolling can be performed by using a plurality of stages of rolling stands.

However, after the trailing end of the rolled material passes through the i-th rolling mill (i-th stand), the trailing end of the rolled material loses the binding force in the width direction until reaching the (i + 1) th stand. It becomes easier to meander. When this is remarkable, the trailing edge of the rolled material collides strongly with the side guides provided to prevent the rolling material from passing through the sheet, and is caught in the (i + 1) th stand while being folded into double or triple layers. Is generated.

This narrowing causes damage to the rolling rolls, deterioration of product surface properties, reduction of rolling line operating rate and product yield. In general, the frequency of occurrence of narrowing at the latter stage stand of a hot continuous finishing mill tends to be higher as the rolled material is thinner, wider, harder, and has a low crown.

As a technique for preventing the meandering of the rolled material that occurs during rolling, the meandering amount is indirectly detected based on the difference between the rolling loads on the driving side and the driven side of the rolling roll, and the gap in the width direction of the rolling roll is detected. Leveling such as differential load type meandering control that performs leveling operation that is opening control, and sensor type meandering control that controls the leveling of the rolling mill by directly detecting the meandering amount of the rolled material by installing a sensor on the rolling mill entrance side. Many methods of preventing meandering by operation have been proposed and are used in some rolling mills.

However, in the meandering control by these leveling operations, 1) In the hot continuous finish rolling mill, the rolling material having a thickness of 1.6 mm or less takes about 0.3 seconds to pass between the final stands. It is difficult to respond, 2) When the flat shape of the trailing edge of the rolled material is not symmetrical with respect to the width direction of the rolled material, it is not possible to detect the accurate meandering amount, 3) Positively change the leveling Therefore, there is a problem that it adversely affects the strip thickness distribution of the rolled material. Therefore, a meandering amount control technique that does not rely on the leveling operation has been proposed, and is disclosed in, for example, Japanese Patent Laid-Open No. 62-62.
No. -40928 is disclosed.

FIG. 7 is a block diagram of a conventional hot continuous finish rolling mill having a meandering prevention function described in JP-A-62-40928. In FIG. 7, the rolled material 21 travels in the direction of the arrow in the figure and is rolled by the rolling roll 22. Further, the tension of the rolled material 21 is adjusted by a looper 23 which is a tension control device provided between the rolling roll 22 and a front stand rolling roll (not shown) of the rolling roll 22.

Here, when the rear end of the rolled material 21 passes through the front stand rolling roll, the rear end of the rolled material loses the width-direction restraining force of the front stand rolling roll, but the roll 24 of the looper 23 and above the looper roll. Since the rolled material 21 is pressed by the pinch rolls 25, the trailing end of the rolled material 21 travels without making a large meander. Therefore, the narrowing-down which is caused by the collision with the side guide 26 is unlikely to occur.

On the other hand, Japanese Unexamined Patent Publication No. 54-19453 discloses a method and a device for preventing a narrowing of a rolled material during cold rolling. In this device, Japanese Patent Laid-Open No. 62-4
Looper roll 24 and pinch roll 2 in No. 0928
Instead of 5, a plate-shaped fixed plate retainer and a movable plate retainer are used. When the cold rolled material slips out, tension is positively applied to the rolled material by these rolling pressing members, the meandering of the trailing end of the rolled material is prevented, and the narrowing is prevented.

[0010]

By the way, Japanese Patent Laid-Open No. Sho 54-54
The device of -19453 prevents the meandering of the rear end of the rolled material,
Although the rolled material is prevented from being narrowed down, since the rolled material pressing member is plate-shaped, scratches and the like are likely to occur, and the portion after pressing the rolled material cannot be used as a product. Further, since the contact resistance is large, the tool is worn out a lot and, in some cases, seizure occurs. However, in the case of cold rolling, normally, the blocks of rolled material do not flow in a batch, but the rolled material flows continuously without interruption. It's just an unsteady task to do. Therefore, the loss of the trailing end of the rolled material tailing operation has a very small effect on the yield reduction, and rather causes problems such as damage to the rolling rolls and reduction of the rolling line operating rate.

On the other hand, in the case of hot rolling, the rolled material is supplied as a block of one block and sequentially rolled by a rolling mill. Therefore, in the apparatus of JP-A-54-19453, the rear end of each rolling block cannot be used as a product, and the yield loss due to the rear end loss is considerably large. Further, if the pressing member is in the form of a plate, it will keep in contact with the hot rolled material for a long time, causing seizure, but there is no suitable material capable of preventing this.

Therefore, in order to prevent the yield decrease and the seizure of the pressing member due to the rear end loss, it is disclosed in JP-A-62-4.
In No. 0928, the rolled material pressing member is changed from a plate-shaped member to a roll. As described above, by forming the rolled material pressing member as a roll and applying a vertical force from above, generation of scratches and the like is prevented, rear end loss is reduced, and yield is improved. Further, since the pressing member has a roll shape, seizure does not occur.

However, pressing the roll from above creates another problem. First, in hot rolling, the trailing end of the rolled material often has an asymmetric shape. For example, when the rolled material rear end portion is narrowed to the left and right as shown in FIG. 7B, the off-center amount of the rolled material rear end portion that is pressure-welded is large, and the rolling roll rigidity is small. As shown in FIG. 7C, the gap distance between the looper roll 24 and the pinch roll 25 changes in the plate width direction. Therefore, in such a case, the rolled material 21 is
7B, meanders in the direction shown in FIG. 7C, collides with the side guide 26, and narrows down.

The present invention has been made in view of such a situation, and in a hot continuous finishing mill, rolling is performed between the trailing end of the rolled material and the rolling stand after the trailing end of the rolled material leaves the rolling stand. The purpose of the present invention is to prevent the rear end of the rolled material, especially the rolled material, from meandering.

[0015]

In order to solve the above-mentioned problems, the invention corresponding to claim 1 is a hot continuous finishing mill comprising a plurality of rolling stands, and at least between the rolling stands. At one place, a pressing roll that is movable in at least the plate thickness direction that sandwiches the rolled material from above and below in the plate thickness direction is provided, and at least one of the pressing rolls is divided into a plurality of rolled material plate width directions. It is a hot continuous finish rolling mill consisting of small rolls and having a meandering prevention function.

The invention according to claim 2 is the invention according to claim 1, in which the meandering measuring means for measuring the meandering amount of the rolled material and the pressing force of the small rolls against the rolled material are provided for each small roll. A drive unit that can be adjusted independently, and a control unit that controls the drive unit based on the meandering amount measured by the meandering measuring means and adjusts the pressing force of each small roll to reduce the meandering of the rolled material It is a continuous hot rolling mill with a meandering prevention function.

[0017]

Therefore, first, in the hot continuous finishing mill having the meandering prevention function of the invention according to claim 1, the press roll is installed and the press roll is divided into a plurality of small rolls in the width direction of the rolled material. Has been done. Therefore, even if the rear end of the rolled material has an asymmetrical shape, the rolled material does not become off-center with respect to the roll, and the rigidity is higher than in the case of an integral pressing roll, and the gap between the pressing rolls is small. Since it is held constant, the occurrence rate of meandering can be reduced.

Further, in the hot continuous finish rolling mill having the meandering prevention function of the invention corresponding to claim 2,
In addition to the same effect as the invention corresponding to, the control means controls the driving device based on the meandering amount measured by the meandering measuring means to adjust the pressing force of the small rolls against the rolled material so as to cancel the meandering. Therefore, the generated meander can be corrected. The above-mentioned pressing force adjustment for canceling the meandering means, for example, if the pressing force on the right side in the width direction of the rolled material is increased, the rolled material tends to bend to the right with respect to the traveling direction. It means adjusting the holding force so that it disappears.

[0019]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a side view of a hot continuous finish rolling mill having a meandering prevention function according to the present embodiment, and FIG. 2 is a view of a hot continuous finish rolling mill having a meandering prevention function according to the present embodiment as seen from above. 3 is a sectional view of the presser roll portion.

FIG. 1 shows an example in which a meandering preventive function is provided on the entry side of the seventh rolling stand (the first to sixth rolling stands are not shown) of the hot continuous finish rolling mill comprising seven rolling stands. In this hot continuous finish rolling mill, a looper 5 for controlling the tension of the rolled material 1 along the traveling path of the rolled material 1,
A meandering prevention mechanism portion for preventing meandering of the rolled material 1, and the rolled material 1
Rolling stand for horizontally rolling steel and rolled material 1 after rolling
And a down coiler 4 for winding up.

The seventh rolling stand is provided with rolling rolls 2a and 2b for rolling the rolled material 1 and a pair of side guides 3 provided to prevent abnormal rolling of the rolled material 1. Further, as shown in the drawing, It consists of a rolling roll drive unit, control unit, and other necessary equipment.

In the meandering prevention mechanism section, the rolled material 1
After passing through a sixth rolling stand (not shown), an upper pressing roll 6 and a lower pressing roll 7 are provided so as to prevent the trailing end of the rolled material 1 from meandering and to press the rolled material 1 to such an extent that the rolled material 1 is not rolled. Has been done.

Further, the upper pressing roll 6 and the lower pressing roll 7 are a drive device 8 for pressing the upper pressing roll 6 in the rolling material plate thickness direction and a driving device for pressing the lower pressing roll 7 in the rolling material plate thickness direction. 9 and a drive device 10 for moving the pressing rolls 6 and 7 in the width direction of the rolled material, which are connected to a support member (not shown).

The upper pressing roll 6 and the lower pressing roll 7 are respectively two small rolls 6a, 6b, 7a, 7b.
And the rolling devices 1 can be pressed independently by the drive devices 8 and 9, respectively. The surface roughness of the small rolls is as rough as possible without damaging the rolled material.

Further, a load cell 11 for measuring the pressing force is connected to the upper pressing roll 6 and the lower pressing roll 7, while a meandering sensor 12 as a meandering measuring means for directly measuring the amount of meandering is provided. It is installed in front of the rolling rolls 2a and 2b.

Based on the signals from the load cell 11 and the meandering sensor 12, a control device 13 for adjusting the pressing force of the driving devices 8 and 9 is connected to the driving devices 8, 9, 10 and the load cell 11 and the meandering sensor 12. The controller 13 controls the entire meandering mechanism section.

Next, the operation of the hot continuous rolling mill having the meandering prevention function of the present embodiment configured as described above will be described. First, when the tip of the rolled material 1 passes the rolling rolls 2a and 2b of the seventh rolling stand, the down coiler 4 starts winding the rolled material 1 and the looper 5 rises. On the other hand, the rolling rolls 2a, 2 at the tip of the rolled material 1
After passing b, the upper pressing roll 6 and the lower pressing roll 7 are driven by the drive device 10 in the center direction of the rolled material, that is, in FIG.
Move to the position shown in. Further, the upper pressing roll 6 and the lower pressing roll 7, which are divided into small rolls by the drive devices 8 and 9, are moved in the thickness direction of the rolled material to clamp and press the rolled material 1 from above and below.

Therefore, even if the rear end portion of the rolled material has an asymmetrical shape on the left and right, as shown in FIG.
The rolled material 1 can be pressed near the centers of the small rolls 6a and 7a. Therefore, the off center of the press roll does not occur, and the rigidity of the roll is short because the roll length is short.Therefore, the gap interval of the press roll does not change in the plate width direction, and the meandering occurrence rate is Significantly reduced.

Next, even if the meandering occurs, it is possible to correct the meandering by adjusting the advancing direction of the rolled material 1 by changing the pressing force of the rolled material 1 in the plate width direction. For example, if the holding force by the small rolls 6b and 7b (right side in the width direction of the rolled material) is increased and the holding force by the small rolls 6a and 7a (left side in the width direction of the rolled material) is reduced, the small roll 6
The rolling speed of the rolled material in parts b and 7b becomes slow, and the small roll 6
Since the rolling material traveling speed of the portions a and 7a becomes faster, the rolling material 1 tries to bend in the direction indicated by the arrow in FIG. 3B (rightward direction in the drawing).

Therefore, if the meandering sensor 12 constantly measures the amount of meandering and the pressing force of the presser roll is monitored by the load cell 7, when the meandering occurs, the controller will drive based on these outputs. 8 and 9 are controlled, and the pressing force is adjusted so as to cancel the meandering of the rolled material. Therefore, FIG.
The meandering can be corrected as shown in (b). Further, this meandering correction can be performed not only at the rear end portion of the rolled material 1 but also at any portion.

As described above, the hot continuous finish rolling mill according to this embodiment is a movable presser divided into a plurality of small rolls 6a, 6b, 7a, 7b for sandwiching the rolled material 1 between the rolling stands from above and below. Since the rolls are provided and the gap distance between the press rolls does not change in the strip width direction, it is possible to prevent meandering and even to prevent narrowing even when the rear end of the rolled material 1 has an asymmetrical shape. It can contribute to improvement of product yield, product quality and rolling line operating rate.

Further, as described above, the hot continuous finish rolling mill according to the present embodiment is divided into a plurality of small rolls 6a, 6b, 7a, 7b for holding the rolled material 1 between the rolling stands from above and below. A presser roll, a meandering sensor 12, a load cell 11, drive devices 8 and 9 and a control device 13 are provided.
Since the gap distance of the press roll does not change in the strip width direction and the rolling direction of the rolled material can be corrected by adjusting the amount of reduction applied to each small roll, the rear end of the rolled material 1 is not left or right. Even in the case of the target shape, it is possible to prevent meandering, to correct when meandering occurs, and to prevent narrowing, which can contribute to improving product yield, product quality and rolling line operating rate. it can.

For example, FIG. 4 shows the number of times of narrowing and the cause of occurrence of narrowing before and after rolling for one month by the hot continuous finish rolling mill of this embodiment. From FIG.
It can be seen that the number of times of narrowing due to the shape of the rear end portion of the rolled material was remarkably reduced by carrying out the present invention.

Next, another embodiment of the present invention will be described. FIG. 5 is a view of a press roll portion of another embodiment of the hot continuous finish rolling mill having a meandering prevention function according to the present invention as seen from above, and FIG. 6 is a sectional view of the press roll portion of FIG.
The same parts as those of FIG. 2 are described with the same reference numerals, and only different parts will be described here.

This hot continuous finish rolling mill is provided with an upper holding roll 16 and a lower holding roll 17 each consisting of five small rolls, and a drive unit 10 for moving each holding roll in the center direction of the width of the rolled material. Not provided. The rest of the configuration is the same as that of the above-mentioned embodiment, so its explanation is omitted.

Next, the operation of the hot continuous finish rolling mill of this embodiment constructed as described above will be explained. Rolled material 1
Before the leading end of the sheet enters the rolling rolls 2a and 2b of the seventh rolling stand, the upper pressing roll 16 and the lower pressing roll 17 are
Are kept open at the top and the bottom at a position apart from the rolled material 1. And, the rolled material tip is the rolling roll 2
At the stage of passing through a and 2b, or at the stage of the rolling weight cutting signal of the stand preceding the 7th stand,
The upper pressing roll 16 and the lower pressing roll 17 are actuated in the direction of the rolled material 1 by respective driving devices, and the rolled material is held at a plurality of positions in the rolled material width direction. The subsequent operation is the same as that of the previous embodiment, so the explanation is omitted.

As described above, the hot continuous finish rolling mill according to this embodiment has the movable upper and lower presser rolls 16 which are divided into five small rolls each for sandwiching the rolled material 1 between the rolling stands from above and below. , 17, the meandering sensor 12, the load cell 11, the drive devices 8 and 9 and the control device 13 are provided so that the gap distance between the press rolls does not change in the plate width direction, and the rolling amount applied to each small roll is adjusted. Since the advancing direction of the material can be corrected, in addition to the effect similar to the above-described embodiment, the number of divided small rolls is large, so that the meandering occurrence rate can be further reduced. Further, since a drive device for moving the press roll in the width direction of the rolled material is unnecessary, the device can be made inexpensive.

Further, although the upper and lower presser rolls are provided in the above two embodiments, for example, a looper roll may be used as the lower presser roll. Further, in the embodiment of the present invention, the seven-stand hot continuous finishing mill was used, but the number of stands is not limited to seven, and any number of stages may be used. Further, in an embodiment of the present invention,
The meandering prevention function such as the press roll is provided in front of the seventh rolling stand, but the meandering prevention function is provided wherever the rolling rolls after the second rolling stand are provided.

Further, the hot continuous rolling mill having the meandering correction function of the present invention is provided with a leveling drive unit, a detection means such as a load sensor in the strip width direction, a leveling control unit, etc., and a meandering correction function by a leveling operation. By combining the above-mentioned meandering correction function of adjusting the pressing force for a small roll and the meandering correction by the leveling operation, it is possible to configure a hot continuous finishing rolling mill capable of achieving more reliable meandering correction. . In such a hot continuous finish rolling mill, the meandering correction function according to the present invention has previously corrected the meandering, so the meandering correction by the leveling operation is slight, and the leveling operation amount that is the gap opening control of the rolling rolls. Therefore, it is possible to reduce the variation in plate thickness of the rolled material. further,
Since the load sensor for the rolling roll for the leveling operation can be used also as the meandering measuring means of the present invention, the meandering sensor 12 in the embodiment can be omitted, and a device having a high meandering prevention effect can be produced for the investment effect. It is possible.

[0040]

As described above in detail, according to the present invention, in the hot continuous finishing mill, after the trailing end of the rolled material leaves the rolling stand, the rolling material reaches the next rolling stand.
It is possible to prevent the rolled material, particularly the trailing end of the rolled material, from meandering.

[Brief description of drawings]

FIG. 1 is a side view of a hot continuous finish rolling mill having a meandering prevention function according to the present embodiment.

FIG. 2 is a view of the hot continuous finish rolling mill having a meandering prevention function according to the present embodiment as viewed from above.

FIG. 3 is a sectional view of a press roll portion of an embodiment of a hot continuous finish rolling mill having a meandering prevention function according to the present invention.

FIG. 4 is a graph showing the number of times of narrowing and the cause of the occurrence of narrowing before and after rolling for one month by the hot continuous finishing mill of the present invention.

FIG. 5 is a view of a press roll portion of another embodiment of the hot continuous finish rolling mill having a meandering prevention function according to the present invention as seen from above.

FIG. 6 is a sectional view of a press roll portion of another embodiment of the hot continuous finish rolling mill having a meandering prevention function according to the present invention.

FIG. 7 is a configuration diagram of a conventional hot continuous finish rolling mill having a meandering preventing function described in JP-A-62-40928.

[Explanation of symbols]

2a, 2b ... Rolling roll, 3 ... Side guide, 6 ... Upper holding roll, 6a, 6b ... Small roll, 7 ... Lower holding roll, 7a, 7b ... Small roll, 8 ... Driving device, 9 ... Driving device, 11 ... load cell, 12 ... meandering sensor, 13 ... control device.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Sadakazu Masuda 1-2 1-2 Marunouchi, Chiyoda-ku, Tokyo Nihon Kokan Co., Ltd.

Claims (2)

[Claims] 1. A hot continuous finish rolling mill comprising a plurality of rolling stands, wherein at least one position between the rolling stands sandwiches the rolled material from above and below in the plate thickness direction. A pressing roll movable in the plate thickness direction is provided, and at least one of the pressing rolls is composed of a plurality of small rolls divided in the plate width direction of the rolled material. Rolling mill. 2. A hot continuous finishing mill having a meandering prevention function according to claim 1, wherein the meandering measuring means for measuring the meandering amount of the rolled material and the pressing force of the small rolls against the rolled material are provided for each small roll. A drive device that can be adjusted independently, and a control device that controls the drive device based on the meandering amount measured by the meandering measuring means and adjusts the holding force of each small roll so as to reduce the meandering of the rolled material. A hot continuous finishing rolling mill having a meandering prevention function, which is characterized by the addition of