JPH04147716A - Method for switching winder on endless hot rolling - Google Patents

Abstract

PURPOSE:To rapidly execute switching without generating the flaw on the products or the variance of sheet thickness at the time of changing the winder by providing the shear inlet side pinch roll at the inlet side of the shearing machine, closing always the shear inlet side pinch roll and applying the backward tension to the strip under finish-rolling. CONSTITUTION:The gate switching and the tension maintenance of the strip 5 during winding are executed with the pinch rolls 4a, 4b composed of large and small rolls just before the winding machine as the main pinch roll. The small pinch rolls are set at the inlet side of the main pinch rolls 4a, 4b, and they are used as the auxiliary pinch rolls 3a, 3b, and the flying of the tail end part of the strip is prevented. And an other pinch rolls are set just before the shearing machine, the backward tension applying to the strip 5 is charged respectively to these, these are used properly for the purpose and so that small diameter can be used as the auxiliary pinch rolls. Therefore, the switching of the front and rear stages of the winder can be rapidly executed and the flaw on the products and the variance of the sheet thickness are not generated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for switching winders in endless hot rolling.

[Prior Art] In a hot rolling line, a rolled material is roughly rolled and finished rolled in units of slabs, and then rolled by a discontinuous rolling method in which the rolled material is wound into a coil using a winder. In this discontinuous rolling method, it is necessary to reduce the impact load when the rolled material is bitten into the rolling mill, and it is necessary to limit the rolling speed during biting. The rolling speed had to be varied in order to adjust the thickness and shape. Particularly when rolling a thin plate, in order to prevent the tip of the rolled material from lifting up during threading, the threading speed is limited until the winding machine starts winding it around the mandrel. in this way,
In the discontinuous rolling method, rolling speed fluctuates, rolling efficiency is low, and there is wasted time for setup etc. between rolling of the preceding rolled material and rolling of the succeeding rolled material, reducing equipment usage efficiency. Ta. In addition, there were problems such as poor shape easily occurring at the leading and trailing ends of the rolled material after finish rolling, resulting in poor production efficiency.

In order to solve these problems, so-called endless rolling has been proposed, in which a plurality of sheet bars are joined together in front of a finishing mill and rolled into a strip. In this endless rolling, the finish-rolled strip is cut into a predetermined length and wound into a coil using a winding machine, but since the strip flows continuously, multiple winding machines are required.
In addition, it is necessary to quickly switch from the winding machine winding the leading strip to the winding machine winding the trailing strip.

Japanese Patent Application Laid-Open No. 61-014 describes a switching technology for such a winding machine.
Publication No. 003 (continuous hot rolling down coiler switching method),
JP-A-61-119326 (rolling line switching gate device) is disclosed.

In the former, as shown in FIG. 4, a main pinch roll 4 and an auxiliary pinch roll 3 (in this example, the main and auxiliary pinch rolls are arranged interchangeably from the present invention) and The winding guide 13 is provided, for example, when switching the winding from a winding machine that is winding a strip to a winding machine at a subsequent stage.

Immediately before the winding machine finishes winding, the auxiliary pinch roll 3 and winding guide 13 of the winding machine are put through the sheet, and the trailing strip passes through the winding machine to the downstream winding machine. Moving. Note that the back tension of the trailing strip is provided by the main pinch rolls 4.

In the latter case, a main pinch roll and an auxiliary pinch roll are similarly used, and the winding machine is switched by moving the deflector IO up and down, as shown in FIG. Rollers 11,12 are provided to prevent scratches on the strip 5 when the deflector 10 is raised and lowered.

[Problems to be Solved by the Invention] However, the following problems remain to be solved in the prior art.

(1) In Japanese Patent Application Laid-open No. 61-014003, when switching the winding machine, it is necessary to cause the leading end of the trailing strip to be caught in the closed main pinch roll 4. If the strip is a thin plate, the cutting tip will fly free, causing damage to the main pinch roll 4 when biting or causing a biting error.

In order to prevent this, it is necessary to take a large angle of attack to receive the strip of the main pinch roll 4, and therefore,
In the above-mentioned prior art, a main pinch roll 4 having an unnecessarily large diameter was used. As a result, the equipment became larger and there were problems in terms of maintenance and management.

Particularly when modifying existing hot rolling equipment, a shearing machine or the like must be installed upstream of the winding machine, which can be said to pose a significant problem in terms of space.

■Also, when the leading edge of the trailing strip passes through the winder, the auxiliary pinch roll 3 and the winding guide 13 must be in a threaded state, but the lower roll of the auxiliary pinch roll 3 and the winding guide 13 A gap inevitably occurs between the leading edge of the strip and the leading edge of the strip.Especially in the case of endless hot rolling, the feeding speed of the strip is high and there is a frequent problem that the leading edge of the trailing strip gets stuck in the gap. The disadvantage is that it occurs.

In addition, in Japanese Patent Application Laid-Open No. 61-119326, since the deflector 10 is provided with rollers 11 and 12, it may seem that there is no concern about the above-mentioned trouble. but,
Since the rollers 11, 12 are installed in a narrow space, they must have a small diameter. Since the diameter of the roller 12 is small, there is a drawback that even if the position where the strip 5 contacts the roller 12 shifts even slightly, the guiding direction of the strip J-tube 5 becomes unstable and winding becomes impossible. Furthermore, there was a problem that the structure of the deflector IO was complicated.

■The rear tension of the trailing strip is determined by the above-mentioned Japanese Patent Application Laid-open No. 61-140.
In the prior art of Publication No. 03, the main pinch roll 4 is used to apply the material, but the continuously flowing strip is cut on the upstream side of the king pinch roll 4. Therefore, the tip of the trailing trip is cut by the shear and the tip of the trailing trip is connected to the main pinch roll 4.
There is a drawback that backward tension (maintaining tension on the strip after the rolling mill) cannot be applied until the strip is bitten.

While this backward tension is not applied, plate thickness fluctuations occur in the finishing mill, resulting in a decrease in yield.

An object of the present invention is to provide a switching method that can solve various problems that occur when switching winding machines in endless hot rolling.

[Means for Solving the Problems J] The present invention solves the above-mentioned problems.Sheet bars are joined in front of a finish rolling mill, finish rolling is performed continuously, and sheet bars are rolled to a predetermined length by a shearing machine. It was applied to a winder switching method in endless hot rolling in which the material is cut into pieces and wound on one of a plurality of winders, and the following method was adopted. That is, a shear entry side pinch roll is provided on the entry side of the shearing machine, and the shear entry side pinch roll is always closed to apply backward tension to the strip during finish rolling, while each winder is provided with a shear entry side pinch roll. Upstream of the main pinch roll, auxiliary pinch rolls that can be opened and closed vertically are provided, and in a winding machine with a winding machine at a later stage, a reciprocating roller is installed downstream of the main pinch roll of the winding machine to switch the strip conveyance direction. Prepare possible movement guides for each.

When switching from the relevant winder to the subsequent winder, open the auxiliary pinch roll of the latter winder, close the main pinch roll of the latter winder, and switch off the auxiliary pinch roll of the latter winder when the strip starts shearing. Close the pinch rolls and open the main pinch roll of the winder, then move the moving guide of the winder forward upstream until the tail end of the leading strip passes the auxiliary pinch roll of the winder, and Before the leading edge of the trailing strip arrives, the auxiliary pinch roll of the relevant winder is opened and the trailing strip is conveyed to the downstream winding machine, and the leading edge of the trailing strip is transferred to the main pinch roll of the trailing winder. When switching from the winder to the front winder, the auxiliary pinch roll of the front winder remains open, and the main pinch roll of the front winder is turned off. Close the moving guide of the front winder to the downstream side to prepare for winding, and when the strip starts shearing, close the auxiliary pinch roll of the winder to pass the tail end of the strip, and This is a winding machine switching method in endless hot rolling, characterized in that the winding machine is switched by biting the leading end of the trailing strip into the closed main pinch roll of the winding machine.

[Effect]

The characteristics of the present invention are as follows.

■The main pinch roll is made up of large and small rolls in front of the winder, and is used to switch the gate and maintain the tension of the strip during winding. An auxiliary pinch roll is used to prevent the tail end of the strip from flying, and a separate pinch roll is provided just before the shear, which is responsible for applying backward tension to the strip. Another advantage is that it is possible to use a small diameter auxiliary pinch roll.

Therefore, when switching the winder from the front stage to the rear stage, or vice versa, the leading strip is accelerated immediately after cutting to create a slight time difference between it and the trailing strip, and within that time difference, the leading strip is accelerated. The winder can be switched by switching the switching gate, and there are no defects on the product.
Further, there is no possibility of plate thickness variation.

In addition, in the present invention, by dividing the winding guide into a moving guide and a fixed guide and moving the moving guide, the gap between the lower roll of the main pinch roll and the winding guide can be reduced, and the tip of the strip can be moved. It is possible to improve sheet threadability.

Furthermore, in the present invention, as described above, the diameter of the auxiliary pinch roll, which has conventionally been used as a large diameter roller, can be reduced, so that equipment costs and maintenance costs can be reduced.

[Example J] The present invention involves joining sheet bars upstream of the finishing mill entrance, endlessly hot rolling the joined sheet bars in the finishing rolling mill, and cutting the rolled strip upstream of the winding machine entrance. This is a winding machine switching method in endless hot rolling, in which a plurality of winding machines arranged in series are alternately switched to continuously wind the strip.

A detailed explanation of the present invention will be given with reference to FIG. Figure 1 schematically shows the vicinity of the winding machine and the shearing machine upstream thereof, where ■ indicates the pinch roll on the shear entry side, 2 indicates the drum shear,
3 is an auxiliary pinch roll, 4 is a main pinch roll, and 5
is a strip, 6.7 is a fixed guide, 8 is a moving guide, and 9 is a table roller. Note that this figure shows the vicinity of the winder on the most upstream side, and there is also a winder on the downstream side.

When the leading edge of the continuously rolled strip reaches and is bitten by the shear entry side pinch roll l, backward tension is generated in the strip 5, and even if the strip 5 is subsequently sheared (to a predetermined length) by the shear 2, , this backward tension is maintained and therefore,
There will be no variation in plate thickness during rolling by the finishing mill. Further, in order to ensure the running performance of the strip 5, the auxiliary pinch roll usually raises the upper roll 3a to a position where it does not interfere even if the tip of the strip 5 flies.

Furthermore, in order to direct the strip 5 toward a downward mandrel (not shown), the upper main pinch roll 4a is offset from the lower main pinch roll 4b and is placed in a state where the strip 5 is bitten (.

The upstream end of the moving guide 8 is located downstream of the upstream end of the fixed guide 6.

When switching from the winding machine to the latter stage, the upper main vinyl roll 4a moves the strip 5 before the winding machine finishes winding.
In order to prevent the upper main pinch roll 4a from pointing downward, the lower surface of the upper main pinch roll 4a is above the upper surface of the strip 5, and the moving guide 8
is brought out to the upstream side to guide the strip 5 downstream,
The distance between the moving guide 8 and the lower main pinch roll 4b is kept narrow.

In addition, when changing the winding machine, it is not possible to slow down the strip feeding speed from the viewpoint of production efficiency, so it is necessary to increase the winding speed of the strip in order to secure preparation time for the above switching operation. There is. At this time, the fluttering of the tail end of the strip is very large due to high speed winding, and in order to suppress this, in the present invention, the auxiliary pinch roll 3a is rolled down. In other words, the present invention uses an auxiliary pinch roll to prevent fluttering of the tail end just before winding is completed, and therefore there is no need for the roll diameter to be as large as in the past, and a small diameter roll is sufficient. (For example, conventionally 80
The diameter can be reduced from 0mm to around 150mm).

When switching from the latter winder to the relevant winder, the upper main pinch roll 4a is replaced by the lower main pinch roll 4b in order to orient the strip 5 downward before the latter winder finishes winding.
The upper and lower main pinch rolls 4a
, 4b puts the strip 5 in a biting state, and the moving guide 8
The upstream end of the movable guide 8 is positioned downstream of the upstream end of the fixed guide 6.

Taking as an example three winding machines arranged in series, FIG. 2 is an explanatory diagram showing a case where the winding machines are switched from the front stage side to the rear stage side. Conversely, FIG. 3 is an explanatory diagram showing a case where the winding machine is switched from the rear stage side to the front stage side.

[Effects of the Invention] The present invention eliminates the need for large-sized or is not a complicated equipment.

It becomes possible to operate at high speed and stably using simple equipment, and there is no damage to finished products and attached equipment, which has an excellent effect on improving productivity in endless hot rolling operations.

Furthermore, since backward tension is always applied to the strip during finish rolling, it is possible to eliminate variations in plate thickness and improve yield6.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of a winding/switching related device that can suitably carry out the present invention, Figs. 2 and 3 are explanatory diagrams of a switching method of the present invention, and Fig. 2 is an explanatory diagram of a switching method of the present invention. , FIG. 3 is an explanatory diagram of switching from a rear stage to a front stage, and FIGS. 4 and 5 are explanatory diagrams of a conventional example. ■--Shear entry side pinch roll, 2--Drum shear 3.3a, 3b-auxiliary pinch roll 4.4a, 4b--Main pinch roll 5--Strip 6.7--Fixed guide 8-・-Movement guide 9-・Table roller lO-・-Deflector 11.12--・-Roller 13... Winding guide Applicant Kawasaki Steel Co., Ltd. No., 1 No., 2 No. 03 Fig. 4

Claims (1)

[Scope of Claims] 1. An endless sheet bar that is joined in front of a finishing rolling mill, subjected to finishing rolling continuously, cut to a predetermined length by a shearing machine, and wound on one of a plurality of winding machines. In a method for switching a winder in hot rolling, a shear entry side pinch roll is provided on the entry side of the shearing machine, and the shear entry side pinch roll is always closed to apply backward tension to the strip during finish rolling, while Each winder is provided with an auxiliary pinch roll that can be opened and closed vertically upstream of the main pinch roll of the winder. Reciprocating movable guides are provided downstream for switching the strip conveyance direction, and when switching from the winder to the latter winder, the auxiliary pinch roll of the latter winder is opened, and the second winder is opened. The main pinch roll of the winder is closed, and when the strip starts shearing, the auxiliary pinch roll of the winder is closed and the main pinch roll of the winder is opened, and then the moving guide of the winder is advanced upstream. , the tail end of the leading strip passes through the auxiliary pinch roll of the winding machine, and before the leading edge of the trailing strip arrives, the auxiliary pinch roll of the winding machine is opened and the trailing strip is unrolled in the succeeding stage. The leading edge of the trailing strip is caught in the main pinch roll of the rear winder, and the winder is switched. The auxiliary pinch roll of the front winder remains open, the main pinch roll of the front winder is closed, and the moving guide of the front winder is retreated downstream to prepare for winding. The winding machine is switched by closing the auxiliary pinch roll of the machine, passing the tail end of the strip, and causing the leading end of the trailing strip to bite into the closed main pinch roll of the preceding winding machine. Winding machine switching method in endless hot rolling.