JP3161368B2 - Recovery method of plate breakage in continuous annealing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for restoring a sheet rupture in which a steel sheet is pulled out of the furnace and restored when the steel sheet breaks, such as in a vertical annealing furnace of a continuous annealing facility for cold-rolled steel sheets (strips). It is about.

[0002]

2. Description of the Related Art Continuous annealing equipment is equipment for heating a metal structure work-hardened by cold rolling to a temperature higher than a recrystallization temperature to grow crystal grains appropriately and to improve mechanical properties.
The coil of the cold-rolled steel sheet is unwound and the steel sheet made continuous by welding is sent to a vertical annealing furnace. In this annealing furnace, the steel sheet is wound around a number of hearth rolls arranged vertically and heated, soaked, cooled, etc. After that, the steel sheet is wound to form a coil.

[0003] In such a continuous annealing equipment, when a steel sheet breaks in a vertical annealing furnace, conventionally, the furnace is opened by searching for the broken part of the steel sheet, and the broken part of the preceding steel sheet and the subsequent steel sheet are broken. Cut and remove the broken part of the steel sheet of, the leading steel sheet is pulled out using the drive roll on the furnace exit side until the rear end is located outside the furnace, and the steel sheet on the subsequent side connects one end of the rope to its tip, The rope wrapped around the downstream hearth roll is pulled by manpower and pulled out until the tip is located outside the furnace. After that, the operation was resumed by welding the rear end of the steel plate on the leading side and the front end of the steel plate on the succeeding side.

When pulling out the steel sheet on the subsequent side by human power, the rope is pulled while a person monitors under or above each hearth roll so that the steel sheet does not meander, and when the meandering occurs, the pulling operation is performed. Has been stopped, the meandering part of the steel plate has been corrected with metal fittings, etc., and the tension work has been resumed.

[0005]

However, when the subsequent steel plate is pulled out of the furnace, the following problems are involved in the manual pulling operation using a conventional rope as described above.

(1) In a vertical annealing furnace, a large number of hearth rolls are arranged above and below, and the meandering of the steel sheet frequently occurs by a manual method. That is, at the time of sheet breaking, since the tension of the steel sheet introduced during normal operation is lost, the meandering suppressing force due to the convex crown of the hearth roll is no longer effective, and manual tensioning work is intermittent tensioning, and the steel sheet has tension. This means that the absence state is repeated, and meandering particularly occurs when there is no tension.

(2) About four people are required to pull out the steel sheet, which requires labor. Further, the pulling operation cannot be performed continuously, and when the meandering occurs, the pulling operation is performed while correcting the meandering, so that it takes time.

[0008] As a technique for taking out a broken plate,
The following technologies have been filed, but the processing equipment for the respective plates differs, and cannot be applied to the vertical annealing furnace targeted by the present invention.

Japanese Patent Laid-Open Publication No. 49-18745 (Cold rolling mill having a broken plate removing device) As shown in FIG. 5, a wire rope surrounding a rolled material S between rolling mills in a continuous cold rolling line 51 or rolled material S
The hook 52 is hooked on the wire rope 53, and these are pulled by a winder 54 via a wire rope 53 to take out the fractured plate in the horizontal direction. However, in the vertical annealing furnace, the steel plate is placed in the furnace. It is not applicable because it is wound around a number of hearth rolls and because the steel sheet on the succeeding side after fracture is drawn out of the furnace and welded to the steel sheet on the preceding side to recover.

Japanese Patent Laid-Open Publication No. 50-75128 (Recovery work method when strip is broken in pickling line layer) As shown in FIG. 6, when strip S is broken in pickling tank 60, exit pinch roller is moved. Drive to pull out the preceding strip S ₁ until the rear end break is positioned outside the tank, reverse the inlet pinch roller, and pull back the succeeding strip S ₂ until the front break is positioned before the inlet pinch roller;
An acid- and heat-resistant rope 62 previously attached to the back of a tank lid 61
The rear end is bound to the tip breaks subsequent strip S _2, by winding the rope 62 by a crane or the like, horizontally pull the succeeding strip S ₂ to the tip fracture portion is located outside the furnace, in Sogai The broken part is recovered by welding. In the case of this pickling tank, there is almost no contact between the strip and the roll, and the strip can be easily pulled out without any problem, but when there are many rolls through which the steel sheet passes, the roll becomes a meandering starting point. Therefore, it cannot be applied to a vertical annealing furnace.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to solve the above problem in the case where a plate breaks in a continuous furnace having many rolls through which the plate passes. It is an object of the present invention to provide a method for recovering a plate breakage in a continuous annealing facility that can be quickly pulled out by a small number of people without meandering the plate.

[0012]

In order to achieve the above-mentioned object, according to the present invention, as shown in FIG. 1, a continuous furnace (such as a continuous annealing furnace) in which a plate is wound around a number of hearth rolls for processing.
When the board breaks inside, one end of a rope (wire rope, nylon rope, etc.) is connected to the tip of the broken part of the succeeding board so that an equal tensile force is applied in the width direction of the board, and the rope is hearth rolled. Wrap around the center of the roll axis, connect the other end of the rope to a tension machine installed outside the furnace, and adjust the tension of a load meter (tension meter) installed at both ends of the hearth roll to a predetermined value. The subsequent plate is pulled out by pulling the rope with a pulling machine, and the rear end of the broken portion of the preceding plate and the front end of the broken portion of the subsequent plate are welded and restored outside the furnace.

[0013] The problem of passing a plate in a vertical continuous furnace is meandering. This is the same when passing through the processing when the plate is broken. When the plate is broken, the temperature is lowered, so that the thermal crown is not provided, so that the problem becomes more apparent. In order to prevent the meandering, it is necessary to exert the effect of the crown by applying tension to the plate, but it is difficult with a few humans. Therefore, in the present invention, as shown in FIG.
The tension machine 5 is controlled based on the tension values at both ends in the sheet width direction measured by the tension meter 6 using the
, The passing of the fractured subsequent plate is performed more quickly and easily.

Further, in order to prevent meandering, it is important to attach the rope to the trailing plate. When tensile force due to rope stop at one side of the plate width direction of the plate, for thereby meandering, in the present invention, the tension in the plate width direction of the trailing side of the plate S ₂ is rests on the uniform. For example, as shown in FIG. 1 (b), two connecting ropes 3a, 3b
Mounting, isosceles triangle of the connection rope 3a, attached via fitting the tip of 3b connection hole 8 drilled in the plate S _2, connecting ropes 3a, so 3b are positioned symmetrically (3a = 3b Is formed). Also, W is set to have a sufficient length. The number of connection ropes may be four or six as long as the connection ropes are symmetrical. Further, the plate S
The connecting rope 3c is wrapped around the connecting rope 3c in an arc shape in the width direction of the connecting rope, and the rope 3 is connected to the center of the connecting rope 3c with a slidable fixing metal 9, and when the tension is uneven, the fixing metal 9 is slid. By fixing, adjustment may be made.

The output of the tension meter 6 is output to a control system 7, and the tension system 5 is automatically controlled by the control system 7 so that the tension value is maintained at an appropriate value. Alternatively, a person may monitor the tension value from the tension meter 6 and manually adjust the tension machine 5. In tensioning, if there is a device or a roll (such as a bridle roll) capable of applying tension to the opposite end (furnace entrance) of the tensioning machine 5, it is easy to apply the necessary tension. The rotation speed of the hearth roll 2 is set to be equal to or slightly lower than the speed of the tensioning machine so that tension can be applied.

In the above-described configuration, a continuous and stable tensile force can be obtained by the tensile machine, and a rope connected to apply a uniform tension in the width direction of the plate can be connected to the broken side plate without meandering. Can be withdrawn. By using a tensioning machine, it is possible to greatly reduce the number of workers, to perform continuous tensioning work, and to eliminate the need to perform the conventional tensioning work while correcting the meandering, Can be pulled out quickly.

The meandering is eliminated as follows. Relationship between hearth roll crown and meandering, tension and meandering: As shown in FIG. 2 (a), when the hearth roll crown is positive, forces Fa and Fb act to move the plate toward the center of the roll, and the negative crown acts. , The force F
Since a 'and Fb' are going to the roll end, Fa 'and Fb'
Are perfectly centered, but if even slightly, Fa '>Fb', the stability is lost and it goes up towards Fa '. Since the forces Fa and Fb are caused by the hearth roll crown, a surface pressure on the hearth roll surface is required.

Therefore, it is necessary to increase the tension in order to increase the surface pressure, and the vertical continuous furnace is operated with the tension increased as shown in FIG. 2 (b). Comparison between manual operation and the present invention: As shown in FIG. 3, in the case of manual operation, a state A where the tension is zero and a state B where the tension is abnormal occur inevitably occur. Does not work, and in B, the plate shifts to one side due to uneven tension in the width direction. On the other hand, in the present invention, a continuous and stable tension is obtained by the tension machine, the meandering suppressing force of the hearth roll crown works sufficiently, and even tension is applied by connecting the ropes, so that when pulling out, Meandering is prevented.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on an embodiment shown in the drawings. This is an example applied to a vertical annealing furnace of continuous annealing equipment. FIG. 1 is a schematic side view showing an apparatus for carrying out a method for restoring a plate breakage according to the present invention, and a front view showing a method for connecting a rope and a rope on a trailing side that has been broken.

The vertical annealing furnace 1 includes a heating zone, a soaking zone, a cooling zone, and the like.
As shown in the figure, the hearth rolls 2 are staggered up and down,
A steel sheet (strip) S is wound around each hearth roll 2 and passed therethrough, and required processing is performed. Some hearth rolls 2 have a positive (convex) crown formed, and tension is introduced into the steel sheet S by making the rotation speed of the roll different between the inlet side and the outlet side, thereby preventing the steel sheet S from meandering. Have been.

In such a vertical annealing furnace 1, a wire rope 3, a tensioning machine 5 equipped with a small winch 4, a tension meter 6, and a control system 7 are used to control a steel sheet on a succeeding side when a steel sheet breaks. carry out the drawer of S _2. The tension meter 6 is a load cell (load cell) installed on each end bearing of the hearth roll at an appropriate position on the upstream side, and detects the tension of the steel sheet by a load acting on the hearth roll. Tension value of the detected right and left is output to the control system 7, this on the basis of the tension value by controlling the torque and speed of the small winch 4, so that a predetermined tension to the steel sheet S ₂ subsequent side is introduced. The control system 7 also controls the rotation speed of each hearth roll 2.

In the above configuration, the vertical annealing furnace 1
If the steel plate breaks in the inside, the recovery process is performed in the following procedure.

(1) When a break occurs, the steel sheet S ₁ on the leading side
And Find broken portion of the subsequent side of the steel plate S _2. Incidentally, the steel sheet S ₁ of the leading side is because it is pulled under high tension, has stopped moving up strongly pulled and several m~ number 10m forward position toward the front at the same time as the rupture. Open the furnace bottom lid of broken portion near each steel sheet, cut and removed removed leading side rear defect and distal defective portion of the subsequent side of the steel plate S ₂ of the steel sheet S ₁ of the outside of the furnace.

(2) The steel sheet S ₁ on the leading side is pulled out using a drive roll (not shown) on the outlet side of the furnace until its rear end is located outside the furnace.

(3) A wire rope 3 is connected to the leading end of the succeeding steel sheet S _{2 from which} the defective portion has been cut and removed, as shown in FIG. 1 (b), and this wire rope 3 is connected to the downstream hearth. The wire rope 3 is sequentially wound around the roll 2 so that the wire rope 3 is located at the center in the roll axis direction, and the other end is connected to the small winch 4 of the tensioning machine 5.

(4) The torque and speed of the small winch 4 of the tensioning machine 5 are controlled on the left and right sides of the steel sheet by the tension meter 6 based on the tension value, so that the hearth roll 2 is rotated and, if necessary, the upstream side. while the tension in the bridle rolls such grant, withdraw the steel plate S ₂ subsequent side to its tip is located outside the furnace.

(5) Wire rope 3 from the succeeding steel sheet S ₂
The removed after integrated by welding the trailing edge of the preceding side of the steel plate S ₁ and the subsequent side of the steel plate S ₂ of the distal end, resume operation by rotationally driving the respective hearth rolls 2 or the like.

When the steel sheet was drawn out according to the present invention and the conventional method in a furnace as shown in FIG. 4A under the following conditions, the results shown in FIG. 4B were obtained.

Steel sheet: low carbon material with a thickness of 0.6 mm x width of 900 mm Hearth roll crown: 0.4 mm on one side / barrel length 1 m Tensioner: tension set value = 150 kg, speed 17 m / min In FIG. Conventionally, only manual power is used, and the present invention is a case of manual control only by a winch, and a case of automatic control with a winch. In the present invention, the plate edge on the trailing side in FIG. It can be seen that the working time for moving the object up to a distance can be greatly reduced. The required personnel and time are as follows.

[Conventional] [4 pullers + 3 supervisors + 1 overall work supervisor] x 3hr = 2
4 persons / hr ・ The present invention (winch manual control) [2 winch operations + 3 monitors + 1 person in charge of overall work] ×
1 hr = 6 people · hr (winch operation is work and instruction) ・ The present invention (winch automatic control) [1 winch monitor + 2 monitors + 1 overall work supervisor] x
0.5 hr = 2 persons / hr The continuous annealing equipment has been described above. However, the present invention is not limited to this, and the present invention can be applied to other continuous furnaces in which a number of hearth rolls on which a plate is hung are provided. Needless to say.

[0031]

As described above, according to the present invention, when a plate is broken in a continuous furnace in which the plate is wound around a large number of hearth rolls, one end of a rope is attached to the tip of the broken portion of the subsequent plate. While connecting so that a uniform tensile force is applied in the width direction, this rope is wound around a hearth roll at the center in the roll axis direction, and the other end of the rope is connected to a tensioning machine installed outside the furnace,
The trailing side plate is pulled out by pulling the rope with a tension machine so that the tension of the load cell installed at both ends of the hearth roll becomes a predetermined value, and the rear end of the fractured part of the leading side plate and the trailing side outside the furnace The following effect can be obtained because the tip of the broken portion of the plate is welded and restored.

(1) When a plate is broken in a continuous furnace having a large number of rolls through which the plate passes, a stable tensile force can be continuously obtained by a tension machine, and a rope connection capable of applying a uniform tension in the width direction of the plate. Thereby, it is possible to safely pull out the broken subsequent plate without meandering.

(2) By using a tensioning machine, it is possible to greatly reduce the number of workers and to carry out tensioning work continuously, and to carry out tensioning work while correcting the conventional meandering. Is eliminated, it is possible to quickly withdraw and quickly restore, and it is possible to significantly reduce costs.

[Brief description of the drawings]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an apparatus for carrying out a method for restoring a sheet according to the present invention, (a) is a schematic side view of a vertical annealing furnace and the present apparatus, (b)
FIG. 4 is a front view showing a method of connecting a rope on a rear side plate that has been broken.

2A is a cross-sectional view showing the relationship between a hearth roll crown and meandering, and the relationship between tension and meandering, and FIG. 2B is a graph showing the effect of line tension on roll crown correction.

FIG. 3 is a graph comparing the change in tension of a fractured succeeding plate between the present invention and a conventional method using human power.

FIG. 4 (a) is a schematic side view showing an example of a vertical annealing furnace to which the method of the present invention is applied, and FIG. 4 (b) is a graph showing the time required for pulling the trailing end of the plate out of the furnace. It is the graph compared by the method.

FIG. 5 is a side view of a rolling mill showing a broken plate removing device in a conventional cold rolling mill.

FIG. 6 is a side view showing a method for restoring a strip in a conventional pickling line when the strip is broken.

[Explanation of symbols]

 S ... Steel plate (strip) 1 ... Vertical annealing furnace 2 ... Heath roll 3 ... Wire rope 4 ... Small winch 5 ... Tensioning machine 6 ... Tension meter (load meter) 7 ... Control system

Claims (1)

(57) [Claims] When a plate is broken in a continuous furnace in which processing is performed by winding the plate around a number of hearth rolls, one end of a rope is applied to the leading end of a broken portion of a succeeding plate with a uniform tensile force in the plate width direction. With this connection, the rope is wound around the hearth roll at the center in the roll axis direction, and the other end of the rope is connected to a tension machine installed outside the furnace, and the tension of the load meter installed at both ends of the hearth roll is set. Pull the rope with a pulling machine so that the value becomes a predetermined value, pull out the succeeding plate, and weld outside the furnace to weld the rear end of the fractured portion of the preceding plate and the distal end of the fractured portion of the succeeding plate to recover. A method for recovering a sheet from breaking in a continuous annealing facility.