JP2004283865A - Method and device for cutting continuously cast slab - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve a product yield by minimizing, with a simple means, a margin of mass relative to a necessary mass required by a rolled product. <P>SOLUTION: In cutting a continuously cast strand into slabs, the slab width is measured by a clamp device while the slab thickness by a length measuring device. A slab cutting instruction length is calculated on the basis of the obtained actual width and thickness of the strand and also on the basis of the instruction mass of the target slab. When the strand is transported and at the point in time at which the transported distance reaches the slab cutting instruction length of the target slab, the strand is clamped to perform cutting of the continuous casting slab. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method and an apparatus for cutting a strand obtained by a continuous casting process of a metal into a slab of a predetermined length, and particularly to a continuous casting slab capable of reducing a margin for a commanded mass (weight) of the cut slab. The present invention relates to a cutting method and an apparatus therefor.
[0002]
[Prior art]
The strands resulting from continuous casting equipment are very long and must be cut to length to be sent to the rolling process. This cutting is generally performed on a slab called a command length based on a required mass (referred to as a command mass) of a rolled product (eg, a slab or a hot coil) and a thickness and width of a strand given from a mold size of a continuous casting machine. This is done by determining the cutting length and operating the gas cutting device based on it.
[0003]
This command length is calculated based on the width and thickness of the strand given from the mold size of the continuous casting machine, and calculates the mass per unit length of the strand (generally called “single weight”). Was determined by dividing the required mass by the unit weight. At that time, it is necessary to ensure that the cut length is not short of the mass of the cut slab.Therefore, a certain margin is given to the command length, and the mass of the cut slab is measured to measure the command length. The correction was made.
[0004]
However, the continuous casting conditions are not always constant, and the time required for the strand to enter the cutting device from the continuous casting machine is different, so that the amount of heat shrinkage generated in the strand is different. For this reason, the unit weight fluctuates, and it is difficult to secure the required slab mass even if the above correction is performed.Therefore, the command length has a large margin for the required mass required for the rolled product, for example, a thick plate. In this case, it is determined that a margin of 500 to 600 kg is provided, which has been a bottleneck for improving the product yield.
[0005]
Patent Document 1 as means for solving such a problem discloses that in continuous casting, a slab weight is calculated by measuring a slab cross-sectional area and integrating in a casting direction to calculate a volume, multiplying the volume by the density, and multiplying the volume by the density. A slab cutting method for determining a cutting position corresponding to a predetermined slab single weight and cutting the slab is disclosed.
[0006]
[Patent Document 1]
JP-A-54-65113
[Problems to be solved by the invention]
However, the means described in Patent Literature 1 has a problem that considerable equipment cost is required for continuously measuring the cross-sectional area of the slab. An object of the present invention is to solve the above-mentioned problems of the prior art, and to reduce the extra mass attached to the required mass required by the rolled product by simple means as much as possible, thereby improving the product yield. An object of the present invention is to provide a method and an apparatus for cutting a cast slab.
[0008]
[Means for Solving the Problems]
The present invention provides a cutting device that cuts a continuously cast strand into slabs, a length measuring device that measures the transport distance of the strand, and a clamp device that can arbitrarily hold and release the strand on the transport path of the continuously cast strand. In cutting a slab of a predetermined length from a strand by using a continuous casting slab cutting equipment mounted on a moving carriage, the clamping device is provided with a slab width measuring means, and the length measuring device is provided with a slab thickness measuring device. Along with the means, when cutting the preceding slab, the strand is clamped by the slab width measuring means to measure the strand width, and when the strand is transported, the strand thickness is actually measured by the slab thickness measuring device to obtain The slab cutting command length is calculated based on the actual width and the actual thickness of the obtained strand and the command mass of the slab to be cut. While the transport distance by transporting the soil to clamp the strands at the time of reaching the slab cut instruction length of the cut slabs moving the continuous casting slab cutting equipment into strands both performs a slab cutting.
[0009]
In the above invention, the difference between the measured mass of the slab cut from the strand and the measured mass of the slab is compared with the measured cutting mass of the slab, and the difference between the measured mass of the slab and the commanded mass of the slab exceeds the allowable range. At times, it is preferable to perform slab cutting by correcting the slab cutting instruction length calculated based on the actual width and actual thickness of the strand and the instruction mass of the slab to be cut, and changing the corrected slab instruction length to the execution cutting instruction length.
[0010]
In addition, when the strand width is actually measured by the strand width measuring device, the slab cutting command length is determined based on a measurement value obtained by performing at least a plurality of times of holding and releasing the strand by the clamp device during the transport of the strand. Is preferably calculated.
[0011]
The above method comprises a cutting device for cutting a continuously cast strand into slabs, a length measuring device for measuring the transport distance of the strand, and a clamp device capable of holding and releasing the strand arbitrarily. In the continuous casting slab cutting equipment mounted on a moving carriage, the clamp device is provided with a strand width measuring means, and the strand transfer distance measuring device is provided with a slab thickness measuring means, and the continuous casting is performed. The slab cutting equipment includes a cutting command length calculating device that calculates a cutting command length based on the command mass of the slab to be cut and the actual strand width and the actual strand thickness obtained by the strand width measuring means and the strand thickness measuring means, and The strand is transported to the continuous casting slab cutting device based on the calculation result of the cutting command length calculation device. When the transport distance reaches the cutting command length of the slab to be cut, a slab cutting control device for issuing a cutting command to perform slab cutting while clamping the strand and moving the continuous casting slab cutting equipment together with the strand is provided. The continuous casting slab cutting device that has been used can be used.
[0012]
The slab cutting instruction length calculating device of the continuous casting slab cutting device includes an actual width and an actual thickness of the strand based on a comparison result between the actual slab mass of the preceding slab and the cutting instruction mass generated by cutting the continuous casting slab. It is desirable to have a calculating means for correcting the slab cutting command length calculated based on the command mass of the scheduled slab and changing it to the execution cutting command length.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a schematic explanatory view according to an example of a continuous casting slab cutting device according to the present invention. As shown here, the slab cutting equipment 4 of the present invention is configured to move on a roller table 2 for transporting a continuously cast strand 1 and a rail 5 laid over the roller table 2. . The slab cutting equipment 4 includes a cart 6, a clamp device 10 mounted thereon, a length measuring device 20 for conveying a strand, and a torch cutter 8 as a cutting device for cutting the strand 1 into the slab 3. The carriage 6 moves synchronously with the clamp 1 when the clamp device 10 clamps the strand 1. The clamp device 10 is provided with a strand width measuring means, and the strand transport distance measuring device 20 is provided with a strand thickness measuring means.
[0014]
FIG. 2 shows an example in which the clamp device 10 is provided with a strand width measuring means. In this example, an openable and closable clamp device 10 is mounted on a gantry 11 installed on a trolley 6, and a cylinder for opening and closing the arm 13 for clamping is a cylinder with a position detector called a “silnack cylinder”. It is set to 14. Thereby, when the arm 13 is fixed at the clamp position on the strand 1, the strand width can be directly measured.
[0015]
As shown in FIG. 1, the slab thickness measuring means is attached to the length measuring device 20 of the transport distance of the strand 1 by mounting the cylinder 22 with the position detector on the carriage 6 and setting the link mechanism 24 and the immovable fulcrum 26. The measurement is performed by connecting to the length measuring roller 27 through the intermediary. In this way, when measuring the length of the strand 1, if the length measuring roller 27 moves up and down due to the fluctuation of the strand thickness, the cylinder 22 with the position detector expands and contracts, whereby the strand thickness can be measured.
[0016]
The length measurement for determining the cutting length of the slab from the strand 1 can be performed by the number of rotations of the length measurement roller 27. Therefore, the length measurement roller 27 is connected to a tachometer 28, thereby The transport distance can be measured.
[0017]
This device includes an arithmetic unit 31 and a control unit 32 for operation and control. The arithmetic unit 31 receives the command mass of the slab to be cut from the setting unit 33. Also, the output of the slab width measured value and the slab thickness measured value by the strand width measuring means attached to the clamp device 10 and the strand thickness measuring device attached to the length measuring device 20 are input to the arithmetic unit 31. Has become. In response to these inputs, the arithmetic unit 31 calculates the unit weight of the strand, and can calculate the slab cutting instruction length of the slab to be cut based on the calculated weight.
[0018]
When the output from the arithmetic unit 31 becomes the slab cutting instruction length, the control unit 32 puts these devices into operation with respect to the strand width measuring means and the torch cutter 8 attached to the clamp device 10, and performs cutting. The clamp of the strand is continued until the work is completed.
[0019]
The procedure of the slab cutting step using this apparatus is specifically shown in FIG. First, when cutting the preceding slab, the strand is clamped by the clamp device, and the strand width is actually measured by the attached slab width measuring means. Next, the clamp is opened, and the strand thickness is actually measured while the strand is being conveyed while the strand thickness measuring means attached to the length measuring device 20 is being measured. The slab cutting instruction length is calculated based on the actual width, actual thickness, and instruction mass of the slab to be cut thus obtained. When the transport distance of the strand reaches the slab cutting command length calculated as described above, the strand is re-clamped, the torch cutter 8 is operated while moving the continuous casting slab cutting equipment in synchronization with the strand, and the slab cutting is performed. Disconnect.
[0020]
By doing as described above, the width and thickness of the strand to be cut can be grasped as actual measurement values, so that the unit weight of the strand can be determined regardless of the elapsed time after the strand is drawn from the continuous casting machine. Accurate recognition can be made, so that the mass of the cut slab can approach the commanded mass.
[0021]
However, the unit weight of the strand may fluctuate for various reasons, for example, depending on the amount of the alloy component. In order to cope with such a fluctuation, as shown by a broken line in FIG. 3, the mass of the slab cut from the strand is actually measured, and the measured mass of the slab is compared with the cutting command mass to calculate a correction coefficient. Then, the correction coefficient may be multiplied by the slab cutting instruction length calculated based on the actual width and actual thickness of the strand and the instruction mass of the slab to be cut, to obtain an execution cutting instruction length, thereby performing slab cutting. This correction need not always be performed, but may be performed when the difference between the measured mass of the slab and the cutting command mass exceeds the allowable range.
[0022]
Further, during operation of the continuous casting machine, for example, when the slab width is changed, so-called tapered slab occurs, and the width of the strand fluctuates greatly. , The actual weight of the slab, and thus the measured mass of the cut slab, will differ significantly from the commanded mass.
[0023]
In order to avoid such a situation, while the strand is being conveyed, the operation of holding and releasing the strand by the clamp device is repeatedly performed, and each time the strand width is measured by the strand width measuring means attached to the clamp device. It is preferable to calculate the slab cutting instruction length based on the obtained actual width. Specifically, for example, the actual average of the obtained actual width is regarded as the actual strand width, or the actual slab thickness is measured by the slab thickness measuring means attached to the length measuring device simultaneously with the measurement of the actual strand width. The cross-sectional area of the strand can be determined from the product of the above, and the cutting length at which the predetermined slab mass is obtained can be determined by integrating the cross-sectional area in the length direction.
[0024]
Although the present invention has been described based on the typical examples, the embodiments of the present invention are not limited to the above examples. For example, the cylinder 14 (22) with a position detector used for measurement of width and thickness may be replaced with a normal cylinder, and a mechanism capable of measuring displacement, for example, a differential transformer may be provided in parallel with the cylinder.
[0025]
【The invention's effect】
According to the present invention, it is possible to accurately give a slab single weight which is a basis for slab cutting. The effect is remarkable in an unsteady state such as when the slab is conveyed when the casting speed changes, when the slab width or thickness changes. Thereby, the surplus mass added to the slab at the time of cutting the slab can be reduced by about 30% as compared with the related art.
[Brief description of the drawings]
FIG. 1 is a schematic explanatory view of a continuous casting slab cutting device used in the present invention.
FIG. 2 is an explanatory diagram of a clamp device used in the present invention.
FIG. 3 is a flowchart of an operation process of the continuous casting slab cutting method according to the present invention.
[Explanation of symbols]
1: Strand 2: Roller table 3: Slab 4: Slab cutting equipment 5: Rail 6: Truck 7: Wheel 8: Torch cutter 10: Clamping device 11 with slab width measuring means 11: Mount 13: Arm 14: Cylinder with position detector 20: length measuring device 21 with slab thickness measuring means 21: rotating shaft 22: cylinder 24 with position detector: link mechanism 25: arm 26: fulcrum 27: measuring wheel 28: tachometer 31: arithmetic device 32: control device 33: Setting section

Claims (5)

A cutting device that cuts the continuously cast strand into slabs, a length measuring device that measures the transport distance of the strand, and a clamp device that can hold and release the strand arbitrarily. In cutting a slab of a predetermined length from a strand using a continuous casting slab cutting equipment mounted on
The clamp device is provided with a strand width measuring unit, and the length measuring device is provided with an attached strand thickness measuring unit,
When cutting the preceding slab, the strand width is actually measured by the strand width measuring means, and when the strand is transported, the strand thickness is actually measured by a strand thickness measuring device,
Calculate the slab cutting instruction length based on the actual width and actual thickness of the obtained strand and the instruction mass of the slab to be cut,
When the transport distance of the strand has reached the slab cutting instruction length of the slab to be cut, the strand is clamped and the slab cutting is performed while moving the continuous casting slab cutting equipment together with the strand. Cutting method for continuous cast slab. Measure the mass of the slab cut from the strand, compare the measured mass of the slab with the cutting command mass, and when the difference between the measured mass of the slab and the cutting command mass exceeds the allowable range, 2. The continuous cast slab according to claim 1, wherein the slab cutting is performed by correcting the slab cutting instruction length calculated based on the actual width, the actual thickness and the instruction mass of the slab to be cut, and changing the slab cutting instruction length to the execution cutting instruction length. Cutting method. In actually measuring the strand width by the strand width measuring device, calculating a slab slab cutting instruction length based on a measurement value obtained by performing at least a plurality of times of holding and releasing the strand by the clamp device during transport of the strand. The method for cutting a continuous cast slab according to claim 1 or 2, wherein: A cutting device that cuts the continuously cast strand into slabs, a length measuring device that measures the transport distance of the strand, and a clamp device that can hold and release the strand arbitrarily. In continuous casting slab cutting equipment mounted on
The clamp device is provided with a strand width measuring device, and the strand transport distance measuring device is provided with a slab thickness measuring device, and
The continuous casting slab cutting equipment includes a cutting command length calculating device that calculates a cutting command length based on the command mass of the slab to be cut and the actual strand width and the actual strand thickness obtained by the strand width measuring means and the strand thickness measuring means. And, based on the calculation result of the cutting command length calculation device, transport the strand to the continuous casting slab cutting device, and clamp the strand when the transport distance reaches the cutting command length of the slab to be cut, and perform the continuous A continuous casting slab cutting device, further comprising a slab cutting control device for issuing a cutting command to cut a slab while moving the casting slab cutting equipment together with the strand. The slab cutting command length calculation unit calculates the actual width of the strand, the actual thickness, and the command mass of the slab to be cut based on the comparison result between the actual slab mass of the preceding slab and the cutting command mass generated by cutting the continuous cast slab. 5. The cutting apparatus for continuous cast slabs according to claim 4, further comprising an arithmetic means for correcting the slab cutting instruction length and changing the slab cutting instruction length to an execution cutting instruction length.

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