JP2820520B2 - Switching method of winder in endless hot rolling - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for switching a winder in endless hot rolling.

[Conventional technology]

In a hot rolling line, rolling is performed by a discontinuous rolling method in which a rolled material is roughly rolled and finish-rolled in slab units, and then wound around a coil by 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 threading speed at the time of biting. For the purpose of adjusting the thickness and the shape, the rolling speed had to be changed. In particular, when a thin plate is rolled, the passing speed is limited until the winding of the rolled material around the mandrel is started in order to prevent the leading end of the rolled material from floating during the passing. As described above, in the discontinuous rolling method, the rolling speed fluctuates, the rolling efficiency is low, and there is wasted time such as setup between the rolling of the preceding rolled material and the rolling of the succeeding rolled material. Had declined. In addition, there is a problem that the leading end and the trailing end of the rolled material are liable to have a defective shape after finish rolling, resulting in poor production efficiency.

In order to solve such a problem, a plurality of sheet bars are joined and rolled into a strip in front of a finishing mill,
So-called endless rolling has been proposed. In this endless rolling, the finish-rolled strip is cut to a predetermined length and wound by a coil by a winder. However, since the strip continuously flows, a plurality of winders are required, and It is necessary to quickly switch from a winding machine for winding a strip to a winding machine for winding a succeeding strip.

Japanese Patent Application Laid-Open No. 61-014003 discloses a technique for switching such a winding machine.
No. (Continuous hot rolling downcoiler switching method)
No. 61-119326 (rolling line switching gate device) is disclosed.

In the former, as shown in FIG. 4, the main pinch roll 4 and the auxiliary pinch roll 3 (in this example, the main and auxiliary pinch rolls are arranged interchangeably with the present application) on the upstream side of the winder, and A winding guide 13 is provided, for example, when winding switching is performed from a winding machine that winds a strip to a subsequent winding machine, immediately before the winding of the winding machine is completed, an assist of the winding machine is provided. With the pinch roll 3 and the winding guide 13 in the passing state, the succeeding strip passes through the winding machine and moves to the downstream winding machine. The back tension of the following strip is provided by the main pinch roll 4.

Also in the latter, similarly, the main pinch roll and the auxiliary pinch roll are used, and as shown in FIG.
The winding machine is switched by moving the deflector 10 up and down. Strip 5 when deflector 10 goes up and down
Rollers 11 and 12 are provided in order to prevent the occurrence of scratches on the sheet.

[Problems to be solved by the invention]

However, the prior art has the following problems to be solved.

In JP-A-61-014003, when switching the winding machine,
It is necessary to make the leading end of the following strip bite into the closed main pinch roll 4. When the strip is a thin plate, the cutting end flies free and damages the main pinch roll 4 during biting, or a biting error occurs.

In order to prevent this, the angle of attack for receiving the strip of the main pinch roll 4 must be made large, and therefore, in the above-described prior art, the main pinch roll 4 having an unnecessarily large diameter was used. For this reason, the equipment becomes large and there is a problem in maintenance management.

In particular, when retrofitting an existing hot rolling facility, a shearing machine or the like must be installed on the upstream side of the winder, which can be said to be a great problem in terms of space.

Also, when the leading end of the following strip passes through the winding machine, the auxiliary pinch roll 3 and the winding guide 13 must be passed through. A gap must be generated between the tip and the end, especially in the case of endless hot rolling, where the feed rate of the strip is high, and the trouble that the leading end of the succeeding strip hits the gap frequently occurs. There is a disadvantage of doing so.

In JP-A-61-119326, since the rollers 11 and 12 are provided in the deflector 10, it may seem that there is no concern about the trouble. However, rollers 11, 12
Must be of small diameter because it is installed in a small space. Since the diameter of the roller 12 is small, there is a disadvantage that the guiding direction of the strip 5 becomes unstable even if the position of the strip 5 contacting the roller 12 is slightly displaced, so that the strip 5 is liable to be unwound. Further, there is a problem that the structure of the deflector 10 is complicated.

The back tension of the following strip is applied by the main pinch roll 4 in the prior art of Japanese Patent Application Laid-Open No. 61-14003, but the cutting of the continuously flowing strip is performed on the upstream side of the main pinch roll 4. Done. Therefore, there is a disadvantage that the back tension (maintaining the tension on the strips other than the rolling mill) cannot be applied until the tip of the following trip is cut by the shear and the leading end of the subsequent trip bites into the main pinch roll 4.

Unless this backward tension is applied, in the finish rolling mill, a thickness variation occurs and the yield is reduced.

SUMMARY OF THE INVENTION An object of the present invention is to provide a switching method capable of solving various problems that occur when switching a winder in endless hot rolling.

[Means for solving the problem]

The present invention has been made to solve the above-mentioned problem, and continuously performs finish rolling by joining sheet bars in front of a finish rolling mill, and cuts the sheet bar to a predetermined length by a shearing machine. The method was applied to a method for switching a winding machine in endless hot rolling for winding to any one of the following, and the following method was adopted. That is, a shear entry side pinch roll is provided on the entry side of the shearing machine,
While the shear-in side pinch rolls are always closed to apply rearward tension to the strip being finish-rolled, each winder is provided with an auxiliary pinch roll that can be opened and closed vertically up and down the main pinch roll of the winder. At the same time, the winder having a winder at the subsequent stage is provided with a reciprocating movable guide for switching the strip conveyance direction downstream of the main pinch roll of the winder, and the winder is arranged at the subsequent stage. When switching to the take-up device, the auxiliary pinch roll of the subsequent take-up device is opened, the main pinch roll of the subsequent take-up device is closed, and at the start of the shearing of the strip, the auxiliary pinch roll of the relevant take-up device is closed and the relevant take-up device is closed. The main pinch roll of the winder is opened, and then the moving guide of the winder is advanced to the upstream side, so that the tail end of the preceding strip passes through the auxiliary pinch roll of the winder, and Before the leading end arrives, the auxiliary pinch roll of the winding machine is opened, the succeeding strip is transported to the succeeding winding machine, and the leading end of the succeeding strip is bitten into the main pinch roll of the succeeding winding machine. When switching from the winder to the preceding winder, the auxiliary pinch roll of the former winder is kept open, the main pinch roll of the former winder is closed, and the former winder is wound. The moving guide of the machine is retracted downstream to prepare for winding, and the auxiliary pinch roll of the winding machine is closed at the start of shearing of the strip,
A winder in endless hot rolling, wherein the winder is switched by passing the tail end of the strip and biting the leading end of a succeeding strip into a main pinch roll in a closed state of a former winder. This is a switching method.

[Action]

The feature of the present invention is that a pinch roll composed of large and small rolls immediately before the winding machine is used as a main pinch roll to switch the gate and maintain the tension of the strip during winding, and a small-diameter pinch roll is provided on the entrance side of the main pinch roll. This is used as an auxiliary pinch roll to prevent flying of the tail end of the strip, and a separate pinch roll is provided immediately before the shear to allow the rear tension of the strip to be imparted, and these are used separately. Therefore, it is possible to use a small-diameter auxiliary pinch roll.

Therefore, when the winding machine is switched from the preceding stage to the succeeding stage, or vice versa, the preceding strip is accelerated immediately after cutting to make a slight time difference from the succeeding strip, and within the time difference, It is possible to switch the winding machine by switching the switching dirt, and there is no generation of flaws in the product and no movement of the thickness.

In the present invention, the winding guide is divided into a moving guide and a fixed guide, and by moving the moving guide,
The gap between the lower roll of the main pinch roll and the winding guide can be reduced, and the threadability of the leading end of the strip can be improved.

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

〔Example〕

The present invention joins the sheet bar upstream from the finishing mill entrance, performs endless hot rolling of the joined sheet bar in the finishing mill, cuts the rolled strip upstream of the winding machine entrance, and cuts the strip. This is a method of switching winding machines in endless hot rolling in which winding is continuously performed by alternately switching to a plurality of winding machines arranged in series.

A detailed description of the present invention will be given with reference to FIG. FIG. 1 schematically shows the vicinity of a winder and a shearing device upstream thereof, 1 is a pinch roll on the shear input side, 2 is a drum shear, 3 is an auxiliary pinch roll, 4 is a main pinch roll. Reference numeral 5 is a strip, reference numerals 6 and 7 are fixed guides, reference numeral 8 is a moving guide, and reference numeral 9 is a table roller. This drawing shows the vicinity of the most upstream winder, and there is a winder also on the downstream side.

When the leading end of the strip to be continuously rolled reaches the shear-in side pinch roll 1, a backward tension is generated in the strip 5 at the time of the bite, and the strip 5 is thereafter sheared (to a predetermined length) by the shear 2. This back tension is maintained, so that thickness fluctuation does not occur during rolling by the finishing mill. Auxiliary pinch rolls are usually strip 5
The upper roll 3a is raised to a position where the top end of the strip 5 does not interfere even if the tip of the strip 5 flies.

The upper main pinch roll 4a is offset from the lower main pinch roll 4b and bites the strip 5 in order to direct the strip 5 to a downward mandrel (not shown). The moving guide 8 is positioned such that 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 subsequent stage, before the winding of the winding machine is completed, the upper main pinch roll 4a
The lower surface of the upper main pinch roll 4a is located above the upper surface of the strip 5 so that the strip 5 is not directed downward, and the moving guide 8 is extended upstream to guide the strip 5 to the downstream side. The interval between the rolls 4b is narrowed.

When the winding machine is switched, the strip feeding speed cannot be reduced in terms of production efficiency. Therefore, in order to secure the preparation time for the switching operation, the strip winding speed needs to be increased. There is. At this time, the tail end of the strip has a very large flapping due to high-speed winding, and in order to suppress the flapping, the auxiliary pinch roll 3a is lowered in the present invention. In other words, the present invention uses an auxiliary pinch roll to prevent flapping at the tail end immediately before the completion of winding, so that the roll diameter does not need to be large as in the past, and a small diameter roll is sufficient. (For example, conventional 800m
m can be reduced to about 150 mm).

When switching from the rear-side winder to the relevant winder, the upper main pinch roll 4a is moved relative to the lower main pinch roll 4b in order to turn the strip 5 downward before the rear-side winder finishes winding. And the upper and lower main pinch rolls 4a, 4b
The moving guide 8 is positioned such that the upstream end of the moving guide 8 is located downstream of the upstream end of the fixed guide 6.

FIG. 2 shows an explanatory diagram in a case where three winding machines are arranged in series and the winding machines are switched from the former stage to the latter stage. On the other hand, FIG. 3 shows an explanatory diagram in the case where the winder is switched from the rear stage to the front stage.

〔The invention's effect〕

The present invention relates to switching the cut strip from the winder to a subsequent or preceding winder and winding the cut strip onto a coil.
Operation can be performed quickly and stably using simple equipment, not large or complicated equipment such as auxiliary pinch rolls and deflectors of the prior art, and damage to products and attached equipment. This has the effect of improving productivity in the endless hot rolling operation.

Further, since the rear tension is always applied to the strip that is being subjected to finish rolling, the thickness can be prevented from fluctuating and the yield can be improved.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a winding / switching-related device capable of suitably implementing the present invention, FIGS. 2 and 3 are explanatory views of a switching method of the present invention, and FIG. 2 is switching from a preceding stage to a subsequent stage. FIG. 3 is a diagram for explaining switching from a subsequent stage to a preceding stage, and FIGS. 4 and 5 are explanatory diagrams of a conventional example. DESCRIPTION OF SYMBOLS 1 ... Pinch roll on the shear side, 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 10 ... Deflector 11, 12 ... Roller 13 ... Winding guide

Continued on the front page (72) Inventor Hiroyuki Yoshimura 1 Kawasaki-cho, Chiba-shi, Chiba Kawasaki Steel Corporation Chiba Works (72) Inventor Fujio Aoki 1 Kawasaki-cho, Chiba-shi, Chiba Kawasaki Steel Corporation Chiba Works (58) Fields surveyed (Int.Cl. ⁶ , DB name) B21B 1/26 B21C 47/34 B65H 23 / 188,23 / 28

Claims (1)

(57) [Claims] 1. An endless hot-rolling method in which a sheet bar is joined in front of a finish rolling mill to continuously perform finish rolling, cut to a predetermined length by a shearing machine, and wound around one of a plurality of winders. In the method of switching the winder in rolling, a shear-in side pinch roll is provided on the input side of the shearing machine, and the shear-in side pinch roll is always closed to apply backward tension to the strip being subjected to finish rolling. The machine has auxiliary pinch rolls that can be opened and closed up and down, respectively, upstream of the main pinch roll of the winder, and a winder having a winder at the subsequent stage is provided downstream of the main pinch roll of the winder. A reciprocable moving guide for switching the strip conveying direction is provided, and when switching from the winding machine to the subsequent winding machine, the auxiliary pinch roll of the latter winding machine is opened, and the main winding of the latter winding machine is opened. Pinch roll At the start of strip shearing, close the auxiliary pinch roll of the winder, open the main pinch roll of the winder, advance the moving guide of the winder to the upstream side, and move the tail end of the preceding strip. Is passed through the auxiliary pinch roll of the winding machine, and before the leading end of the following strip arrives, the auxiliary pinch roll of the winding machine is opened, and the following strip is transported to the subsequent winding machine, The leading pinch roll of the succeeding winder is engaged with the leading end of the following strip to switch the winder, and when switching from the winder to the preceding winder, the auxiliary pinch roll of the preceding winder is opened. The main pinch roll of the former winder is closed, the moving guide of the former winder is retracted to the downstream side to prepare for winding, and the auxiliary pinch roll of the relevant winder is started at the time of starting the shearing of the strip. Close and Switching the winder in endless hot rolling, wherein the winder is switched by passing the tail end of the lip and biting the leading end of the following strip into the main pinch roll in the closed state of the preceding winder. Method.