JPH07284852A - Method for preventing scratch in payoff reel - Google Patents

Abstract

PURPOSE:To prevent generation of surface scratches in uncoiling a metallic strip by stopping force for expanding a payoff reel when the remaining length of a coil becomes a specific length. CONSTITUTION:A strip steel S wound in a coil is passed to the following process from a payoff reel 1 to a transportation roll 2 and to a tension adjusting roll 3. The payoff reel 1 is provided with a wedge type uncoiler 11. Data for remaining length of the coil of the payoff reel 1 is sent by a data source 12 to a computer 13 for setting timing. When the thickness of the remaining coil becomes a prescribed quantity, a command is issued by the computer 13 for the revolution control of a rotary motor 14 and the reduction of an expanding force of an external reel 15 in the uncoiler 11. The reel turns to a state where no deformation is generated on the inside diameter of the reel while a coiled state is maintained; and the state is such that no rubbing takes place against each other of the strip steel S.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is designed to pass a continuous metal plate wound in a coil shape, as in the case of unwinding the strip steel sheet at pickling, cold rolling and continuous annealing. A method for preventing the occurrence of surface flaws on a continuous metal plate that occurs during the process of operating a payoff reel for rewinding for a plate, in particular, pickling, cold rolling, continuous annealing line, pressure adjustment, installed on the payoff reel on the entry side. The present invention relates to a method for preventing the occurrence of surface flaws by controlling the expansion of pay-off reels on a precision coil line, a shear line, and a plating line.

[0002]

2. Description of the Related Art As is well known, when a coil of a continuous plate such as a strip steel plate is rewound, a driving core material for rotating the coil is inserted with a reduced diameter when the coil is inserted into the coil. For easy rewinding after insertion, in order to increase the frictional force between the reel surface and the coil inner surface in order to prevent the occurrence of slip between the reel and the coil, the outer surface divided into a plurality of sections The core member is inserted inside the portion, the inner surface of the divided outer surface portion and the outer surface of the core member are formed into a wedge shape, and a so-called wedge type uncoiler is provided in which the outer surface portion is expanded by the insertion of the core member. ing.

As a result, when the coil is unwound, a force in the expansion direction is always applied, and the operation is performed in the expansion direction in consideration of the frictional force on the reel surface.

However, when the coil is rewound and the remaining length of the coil is reduced, if the operation is performed with the force in the reel expanding direction being applied, the expanding force from the inside of the coil is applied in addition to the winding loosening force due to the elastic force of the coil. As a matter of fact, the occurrence of loosening promotes the displacement of the plates in the coil winding portion, and a surface defect (gouge) occurs on the displaced surface.

Particularly, in the double cone type reel having a structure in which the coil is inserted from both the driving side and the operator side and the full width of the coil and the outer circumference of the reel are not in contact with each other, the coil thickness is small. In this state, the expansion force on the outer surface of the reel split surface overcomes the resistance of the wall thickness of the coil and the cone insertion part expands, causing deformation in the width direction that the deformation of the end part becomes larger than the center part of the plate width. As a result, the degree of surface flaw is further increased. Further, in the case of a pickling front surface where no oil is attached to the coil, a pressure adjusting front surface, or a continuous cold rolling / injection side with a small amount of oil coating, this state is further aggravated.

[0006] This surface flaw has a problem in that, particularly in the case of thin materials, it causes a piercing defect in the post-process, and even in the case of thick materials, the surface appearance is significantly deteriorated and cracks occur during processing by the user. It also causes it to occur.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to provide means for preventing the occurrence of surface flaws when unwinding a coil-shaped metal strip plate using such an expansion reel.

[0008]

The present invention has been completed by obtaining the following findings as a result of investigating the relationship between the expansion of the expansion reel and the slip phenomenon between the winding strips.

(1) By reducing the tension of the wound strip plate, the moment of slip generation between the coil and the reel is reduced, and slipping is less likely to occur even when the reel is held in position.

(2) The wall thickness is reduced, and the arm for rotational moment is reduced. Even if the reel is held in position, it will not slip easily.

(3) Since the remaining coil length is reduced and the solenoid valve is held in position, the time until slipping out is short, and therefore the change in the inner diameter due to leakage at the solenoid valve is small. Even if the reel is held in position, it will not slip easily.

(4) The thickness of the coil is small so that the coil does not accelerate but decelerates, and damage such as a plate loosening accident due to operation with low tension can be small.

That is, the present invention is a method for controlling the reel expansion at the time of rewinding of the strip-shaped plate which is rewound while applying a force in the expansion direction to the inner surface of the strip-shaped plate wound on the pay-off reel whose diameter can be increased. Therefore, when the remaining coil length reaches a specific length, the application of force in the expansion direction of the payoff reel is stopped.

To stop the application of the force in the expanding direction of the pay-off reel, means such as adjusting the expanding hydraulic pressure in the decreasing direction can be adopted, but the hydraulic mechanism for expanding and contracting the reel is neutralized. The simplest and surest thing to do is

The specific length of the coil remaining length for stopping the operation of the pay-off reel in the expanding direction is determined by the relationship between the oil coating state of the coil, the tension setting during unwinding, the reel surface state and the coil thickness state. Is determined by the conditions under which slip is prevented between the inside of the coil and the reel and the expanding force is not excessively applied to the coil.

As a control means for this purpose, a solenoid valve control method using a combination of a coil residual length calculator and a three-way solenoid valve can be adopted.

[0017]

[Function] By the expansion control of the reel that does not give the expansion force when the coil wall thickness is reduced, the operating condition can be established under the condition of maintaining the coil state by the reel and ensuring the necessary grip force without deformation of the inner diameter of the reel. It is possible to prevent rubbing between the strips in the wound state.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 shows an outline of an apparatus for carrying out the present invention.

In the figure, the strip steel plate S wound up in a coil shape is passed through the conveying roll 2 and the tension adjusting roll 3 by the operation of the pay-off reel 1 and then passed to the next step. This pay-off reel 1 has a wedge-type uncoiler 11, and information from the data source 12 of the remaining length of the unwinding coil set by the actual results is sent by a signal from the timing setting computer 13 based on the remaining coil thickness.
The control of the reel rotation motor 14 and the expansion of the outer reel 15 of the uncoiler 11 are controlled.

This expansion control is performed by a three-way solenoid valve 17 that controls the supply of pressurized oil to the rotary expansion cylinder 16 that controls the expansion and contraction of the outer reel 15 of the uncoiler 11. In the figure, 18 is a tank of pressure oil for operating the three-way solenoid valve 17, and P is an operating pump.

According to the actual results, in the case of ordinary steel having a width of 600 to 1880 mm and a thickness of 2 to 6 mm, the coil thickness is 10
When it reached 0 mm, the unwinding tension of the reel was set to 50% or less of the steady operation, the solenoid valve 17 was switched to a position for holding the reel position, and the expansion of the outer reel 15 of the uncoiler 11 was stopped. As a result, no rubbing of the plates occurred during unwinding from the coil shape, and strip steel plates without surface flaws could be passed.

In the process of this operation, if the reel position holding state is continued for a long time, the solenoid valve 17 may leak, and the reel inner diameter position may not be held, and slip between the inside of the coil and the reel may cause a great trouble. Therefore, it is necessary to continuously perform the above-mentioned operation, because it is impossible to perform the operation while always maintaining the position.

That is, at the time when the line is stopped, the process is once returned to the enlargement and started, the transitional state immediately after the start is ended, and the process is shifted to the present system again.

The unwinding tension on the front side needs to be set lower than the winding up tension from the viewpoint of preventing flaws in the tightening, and is 1.0 kg / mm ² in the pickling and cold rolling steps.
Hereinafter, it was necessary to set 3.0 kg / mm ² or less for continuous annealing, electrolysis, and pressure adjustment. Further, the limit value of the coil wall thickness for hydraulic control needs to be determined by the difference in the oiling state in the previous process.

[0025]

The present invention has the following effects.

(1) When the strip plate is unwound from the coil, even if the pay-off reel is operated at a high speed, surface defects due to abrasion of the strip plates are eliminated.

(2) In the double cone type pay-off reel cold rolling mill, the abnormal deformation of the coil inner diameter portion disappeared when the coil outer diameter became small. It is possible to prevent the occurrence of plate breakage due to ear tears in one stand.

[Brief description of drawings]

FIG. 1 shows an outline of a control system for carrying out the present invention.

[Explanation of symbols]

S Strip steel plate 1 Payoff reel 2 Conveying roll 3 Tension adjusting roll 11 Wedge type uncoiler 12 Actual data 13 Timing setting computer 14 Reel rotary motor 15 External split reel 16 Expansion / reduction rotary cylinder 17 Solenoid valve 18 Three-way solenoid valve pressure oil tank P Three-way solenoid valve actuation pump

Claims (1)

[Claims] 1. A method for preventing flaws in a pay-off reel by controlling reel expansion when unwinding a strip-shaped plate that is unwound while exerting a force in the expansion direction on the inner surface of a coil inserted in a pay-off reel whose diameter can be expanded or contracted. Then, when the remaining coil length reaches a specific length, a flaw prevention method for a pay-off reel that stops applying force in the expanding direction of the pay-off reel.