JP2000248319A - Steel strip passing method at continuous heating facility, and passing position control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a steel strip passing method, and a passing position control device in a continuously heating facility capable of improving the service life of a conveyor roll for a heating furnace. SOLUTION: A center position control device 4 is arranged upstream of a continuous annealing furnace 1. The center position control device 4 periodically changes its target control position according to the signal from a function generator. The position of the outer circumferential surface of a hearth roll 2 with which an edge portion of a steel strip 3 to be conveyed is brought into contact is dispersed in the axial direction, and the wear per unit time of the hearth roll 2 is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of passing a steel strip in a continuous heating treatment facility for continuously heating a steel strip, such as a continuous annealing facility for producing a stainless steel sheet, and a threading position control device therefor. About.

[0002]

2. Description of the Related Art When a steel strip is continuously conveyed to a continuous heat treatment furnace such as a continuous annealing furnace, a center formed of a steering roll or the like is provided upstream of the heat treatment furnace in order to pass the steel strip along a pass line. A position control device is arranged to control the running position of the steel strip at the line center.

Here, the center position control of the steel strip is performed as follows.
Since the purpose is to control the central portion of the steel strip in the plate width direction to pass through the pass line, the control target position is always a fixed line center.

[0004]

In a continuous heating furnace for a steel strip such as a stainless steel strip, as described in Japanese Patent Publication No. 5-86450, a transfer roll of the heating furnace has an outer peripheral surface. It is made of heat-resistant sheet material such as asbestos.
For this reason, the transport roll has a lower surface hardness than the metal roll.

However, in the above-mentioned conventional threading method, since the steel sheet is always conveyed so that the center in the sheet width direction passes through a fixed line center, the edge position of the steel strip to be conveyed is always fixed. Pass through. As a result, the edge portion of the steel strip that is continuously conveyed always contacts only a certain place on the outer peripheral surface of the conveyer roll.
Wear is fast at that position. That is, only the specific roll portion that comes into contact with the edge portion is extremely worn, and there is a problem that the wear of the edge portion shortens the life of the transport roll.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and can improve the life of a conveying roll for a heating furnace, and can control a steel strip passing method and a sheet passing position in a continuous heating treatment facility. It is an object to provide a device.

[0007]

In order to solve the above problems, the present invention is to periodically change a control target position of a center position control performed upstream of a heating furnace in a sheet width direction. is there. That is, claim 1 of the present invention
The invention described in the above, when continuously transporting the steel strip to a continuous heat treatment furnace, in a continuous steel sheet passing method in a continuous heat treatment equipment that performs a center position control the traveling position of the steel strip to the line center A steel strip passing method in a continuous heat treatment facility, characterized in that a control target position in the center position control is periodically changed around a line center in a steel strip width direction.

Next, a second aspect of the present invention is a control device arranged upstream of the continuous heat treatment furnace, wherein the steel strip position detecting means detects the position of the steel strip, and the position of the steel strip is detected. A center position control device for controlling the traveling position of the steel strip to a line center based on a signal from the means, and a passing plate position control device in a continuous heating treatment facility, wherein the center position control device sets a control target position, A threading position control device in a continuous heating treatment facility, comprising target position changing means for periodically changing the width of a steel strip centering on a line center.

According to the present invention, the width of the steel strip in contact with the conveying roll of the heating furnace is changed by periodically changing the control target position of the center position control device for the steel strip located upstream of the continuous heating furnace. Since the steel strip is conveyed to the heating furnace while changing the position of the central part in the direction of the steel strip in the width direction of the steel strip, it is possible to disperse the positions where the steel strip edge portions of the conveyance roll for the heating furnace come into contact. As a result, the transfer roll replacement cycle becomes longer.

[0010] The period of the periodic change of the control target position is set to a long period that does not cause the meandering beyond the allowable range.

[0011]

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram for describing an embodiment based on the present invention. In this embodiment, an annealing furnace 1 is illustrated as a continuous heating furnace, and a pass line is provided in the annealing furnace 1. A plurality of hearth rolls 2 are arranged along.

A steering roll 5 constituting a center position control device 4 is disposed upstream of the annealing furnace 1. A deflector roll 6 is arranged before and after the steering roll 5 so that the steel strip 3 is wound around the steering roll 5 with a predetermined tension. Reference numeral 7 denotes a steel strip position detecting means which detects a width direction position of the steel strip 3 and supplies a detection signal to a controller 8 described later.

As shown in FIG. 2 which is a plan view, the distal end of the piston rod 9a of the hydraulic cylinder device 9 is connected to one end in the axial direction of the steering roll 5, and the cylinder device 9 is operated by operating the cylinder device 9. The shaft of the steering roll 5 is tilted in the front-rear direction, and the position of the conveyed steel strip 3 in the width direction is changed and adjusted. Reference numeral 10 denotes the cylinder device 9
The control position of the control valve is adjusted by a command from the controller 8.

The controller 8 of this embodiment includes a function generator 11 (target position changing means) and inputs a signal from the steel strip position detecting means 7. The above function generator 1
For 1, for example, a periodic function such as a sine wave having a cycle of about 2 hours and an amplitude of 50 mm is used, and an output value of the function is supplied to the controller main body 12.

The controller body 12 calculates the signal δ from the function generator 11 based on the deviation Δ from the actual line center in the steel strip width direction based on the signal of the steel strip position detecting means 7.
To obtain a virtual deviation signal Δ ', and the deviation signal Δ'
Is supplied to the control valve 10 in accordance with the change amount of the inclination of the steering roll 5 at which is zero. In the continuous annealing equipment provided with the center position control device 4 having the above-described configuration, the target control position in the control device 4 is controlled by the signal from the function generator 11 in the width direction of the steel strip 3 around the line center which is the original control position. It changes periodically.

For this reason, the steel strip 3 in the hearth roll 2
Are also dispersed by periodically changing in the roll axis direction, thereby avoiding concentrated contact with a part of a narrow area as in the related art. As a result, the amount of local wear on the hearth roll 2 per predetermined operation time is reduced, and the replacement cycle of the hearth roll 2 is extended. As a result, the cost required for the hearth roll 2 can be reduced, and the decrease in productivity of the annealing equipment due to the replacement of the hearth roll 2 can be suppressed to a small level.

In the above embodiment, the continuous annealing equipment is described as an example, but the present invention may be applied to other continuous heat treatment equipment. Further, the configuration of the center position control device 4 is not limited to the above configuration, and may be another existing center position control device. In this case, by adopting a configuration similar to the above, the present invention can be realized without changing the basic part of the conventional control. That is, except that the function generator 11 is provided and a correction process of subtracting the actual deviation based on the signal from the steel strip position detecting means 7 with the signal from the function generator 11 is separately added, the basic center position The control part can be adopted as it is conventionally.

[0018]

Next, the results obtained by adopting the above embodiment will be described. In this embodiment, the signal from the function generator 11 is periodically changed as shown in FIG. That is, the control target position of the center position control device 4 arranged on the entrance side of the annealing furnace 1 was changed at an amplitude of 50 mm in the width direction of the steel strip every eight hours.

The steel strip 3 was a stainless steel strip having a width of 1000 mm. The hearth roll 2 after the operation was performed for 10 days under the control of the above embodiment was as shown in FIG. 4 which is a side view. The symbol H is a portion worn by contact with the steel strip edge. For comparison, when the control target position of the center position control device 4 was fixed to the line center, the side view of the hearth roll 2 after the operation was performed for 10 days was as shown in FIG.

In the operation in the comparative example, as a result of the edge portion of the steel strip 3 being brought into concentrated contact with a narrow area of the roll 2, as shown in FIG. It was also found that the surface of the steel strip to be treated had surface flaws caused by the wear. On the other hand, in the case of the present invention, as shown in FIG. 4, the worn portions were dispersed in the axial direction, and the surface of the steel strip was not damaged at all due to the wear. .

As a result, the life of the hearth roll 2 can be extended from the conventional 10 days or less to 20 days, and the cost of the hearth roll 2 can be reduced. In addition,
In the above embodiment, the case where the cycle is 8 hours and the amplitude is 50 mm has been described. However, the present invention is not limited to this, and the cycle and the amplitude may be appropriately selected according to the equipment configuration.

[0022]

As described above, when the present invention is employed, the passing of the steel strip while dispersing the abrasion position caused by the steel strip edge portion in the transport roll of the continuous heat treatment furnace in the axial direction is performed. Can be. Therefore, there is an effect that the life of the transport roll can be extended and the cost of the transport roll can be reduced.

Further, since the frequency of replacing the transport rolls can be reduced and the total time required for the replacement can be reduced, there is an effect that the productivity in the heat treatment equipment is also improved. In addition, since extreme partial wear can be prevented, there is also an effect that a surface defect generated on the surface of the steel strip and caused by wear of the transport roll can be prevented.

[Brief description of the drawings]

FIG. 1 is a diagram showing a continuous heat treatment facility according to an embodiment based on the present invention.

FIG. 2 is a diagram illustrating a center position control device according to an embodiment based on the present invention.

FIG. 3 is a diagram illustrating an example of an output value (change of a control target position) of a function generator in the embodiment.

FIG. 4 is a view showing a wear state of a hearth roll when the present invention is adopted.

FIG. 5 is a view showing a state of wear of a hearth roll in a conventional case.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Continuous annealing furnace 2 Hearth roll 3 Steel strip 4 Center position control device 5 Steering roll 6 Deflector roll 7 Steel strip position detecting means 8 Controller 11 Function generator (target position changing means)

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4K034 AA16 BA04 CA05 DA02 DB02 DB04 EA09 EA12 EB01 4K037 EB13 EB14 FH01 4K043 AA01 DA05 EA07 FA04 FA11 GA07 GA10

Claims (2)

[Claims] 1. A method for continuously passing a steel strip to a continuous heat treatment furnace, wherein the running position of the steel strip is controlled to a line center by a center position control. A steel strip passing method in a continuous heating treatment facility, wherein a control target position in position control is periodically changed in a steel strip width direction around a line center. 2. A control device arranged upstream of a continuous heat treatment furnace, comprising: a steel strip position detecting means for detecting a position of a steel strip; and running of the steel strip based on a signal from the steel strip position detecting means. A center position control device for controlling a position to a line center; and a strip position control device in a continuous heating treatment facility having a center position control device for controlling a position to a line center. A threading position control device in a continuous heating treatment facility, comprising a target position changing means that changes periodically.