JP3402545B2 - Method and apparatus for controlling cutting of continuous cast slab - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a slab cutting technique in a continuous casting technique, and more specifically, when cutting a continuous casting slab with a gas cutting torch, the cutting state is accurately and quickly automatically. The present invention relates to a method and a device for making a judgment and performing cutting control based on the judged cutting state.

[0002]

2. Description of the Related Art Cutting operation of a slab in continuous casting is shown in FIG.
The gas cutting torch 3 of the automatic slab cutting device, which is arranged above the slab 1 on the transport roll 2 so as to face the outline, as shown in FIG.
First, the preheating gas is jetted to preheat the side end portion of the slab 1, and then the cutting gas is jetted from the gas cutting torch 3 to cut the slab 1, and the gas cutting torch 3 is moved in the slab width direction. To rampage. Gas cutting torch 3 until cutting is completed
Moves transversely in synchronism with the movement of the slab 1, and when cutting is completed, immediately returns to the original position in preparation for the next cutting. It is customary that the above cutting operation is automatically performed by a preset prologue according to the size of the cast piece, the cutting length of the cast piece, and the like.

By the way, in the cutting of such continuously cast slabs, the slabs often fail to cut (incomplete cutting,
Leftovers, etc.) occur. As a countermeasure for this, there is a method of lengthening the preheating time of the side end of the slab, but since the preheating time is limited by the speeding up of cutting accompanying the speeding up of casting, depending on the cooling condition of the slab, etc. May fail. If the cutting is not successful, the subsequent cutting is also incomplete. Further, even if the cutting is performed smoothly, uncut portions may occur in some places, and the uncut portions may cause uncutability.

If the detection of cutting failure such as failure or uncut cutting of the slab in this slab cutting operation is delayed, it becomes impossible to redo cutting within a limited time until the next cutting, so that continuous casting operation is performed. Not only does it hinder the operation, but the slabs that are not cut into a predetermined length are stagnated in the transfer line. Therefore, it is required to constantly monitor the cutting state during cutting of the continuously cast slab and promptly detect cutting failure such as cutting failure or uncutting and take countermeasures.

[0005]

However, as means for detecting abnormalities during cutting of continuously cast slabs, mainly when a dedicated worker visually observes the cutting state of the slabs and a cutting failure occurs. Since the automatic slab cutting device is switched from automatic to manual and necessary measures are taken, accurate and quick response is difficult and it is not preferable because it leads to an increase in the number of workers.

Therefore, means for automatically determining the quality of the cut state have been proposed, for example, in Japanese Patent Laid-Open Nos. 58-163560 and 58-202960, but none of them is practical. That is, the former means
It mechanically traces the cut part with a roller,
In order to avoid thermal influence on the roller, the roller and the blow tube (gas cutting torch) must be sufficiently separated from each other, and quick determination is impossible. The latter means is a method of detecting blowback of gas generated when a cutting failure occurs, and detecting the cutting failure by detecting abnormal vibration of the blowing tube, but vibration may not occur depending on the mounting state of the blowing tube, Further, it is difficult to distinguish it from vibration due to other factors, and thus reliability is low.

Further, a cutting abnormality detecting means for automatically judging whether the cutting is good or bad by using a sensor or the like is disclosed in Japanese Utility Model Laid-Open No. 61-4872.
However, there are some drawbacks. That is, the image sensor and lighting cut the opening (slit)
It is a method to detect the cutting situation by creating a shadow on the torch and processing the image, but this method installs the detection device on the torch carriage, so it is necessary to protect the sensor etc. due to heat, and There is a drawback that it is difficult to detect abnormalities.

The present invention has been made in order to solve the above problems of the prior art, and proposes an automatic cutting control means capable of surely and promptly responding to a defective cutting. Is.

[0009]

A method for controlling cutting of a continuously cast slab according to the present invention is a method of cutting a slab when a gas cutter is traversed across the continuously cast slab to cut the slab. An image sensor is used to capture the splash splash state of the image, the image is divided into multiple areas, and a score is set in advance for each area according to the abnormal frequency, and the total score of each area of the splash splash site during cutting. Is determined to be abnormal cutting, and the cutting torch is returned to at least the defective cutting position, and cutting is performed again from the returning position. Further, as a method for determining the disconnection abnormality in this method,
The image picked up by the image sensor is binarized to determine the area of the splashed portion of the splash within a predetermined area, and if the area value exceeds a preset threshold value, it is determined that the cutting is abnormal. The method of doing can also be used.

As a device for carrying out the above cutting control method, a predetermined slab conveying line downstream of a slab automatic cutting device for cutting a slab by traversing a continuous casting slab with a gas cutting torch is provided. An image sensor that is installed at intervals and that captures the splashing state of the slab during cutting, and the image captured by the image sensor is divided into multiple areas, and cutting is performed according to the number of points determined for each area. An image processing device that calculates the total score of the splash scattered parts, and if the total score is equal to or greater than a predetermined threshold value, it is determined that the cutting is abnormal, and an abnormal signal is output to the slab automatic cutting device. An abnormality determining device, and a control means for returning the cutting torch to at least the defective cutting position when a cutting abnormality occurs, and controlling the automatic slab cutting device so as to perform cutting again from the returning position. And it is characterized in that it is al configured.

When cutting a cast piece from above with a gas cutting torch, red hot molten metal droplets called splash, which are directed downward from the cut portion, scatter during normal cutting. On the contrary, when the cutting is abnormal, the defective cutting portion serves as a barrier and the splash does not scatter to an appropriate place (mainly below). According to the present invention, since the image of such a splashing splash state is captured by the image sensor, the splashing splash state at the time of normal cutting and at the time of abnormal cutting can be reliably detected. Further, in the present invention, the image of the cutting portion picked up by the image sensor is divided into a plurality of areas, and the points are given weights in advance by the abnormal frequency in each area.
It is possible to judge the abnormality depending on the place.

That is, it is known that the splash is scattered in a specific direction when the cast piece is normally cut. However, when the cutting is abnormal, the splash direction spreads in all directions except the lower part. By checking the location, it is possible to detect abnormal cutting. Therefore, in the present invention, a plurality of areas are provided, a score is set in advance for each area, and the score is calculated in total for each area in which a splash occurs and is affected, so that it is set in advance. It is possible to determine the disconnection abnormality by comparing with the threshold value.

Further, in place of the above-mentioned score system, the image of the image sensor is binarized, and it is determined that the cutting is abnormal even when the area of the splashed portion within the predetermined area exceeds a predetermined value. can do.

As described above, since the cutting abnormality judging method of the present invention judges the quality of the cutting based on the splash direction of the splash at the time of cutting, it is possible to automatically and accurately judge the cutting abnormality.

When a cutting abnormality is detected, the gas cutting torch is immediately returned to the defective cutting portion. However, since the cutting abnormality is quickly detected, the torch idle distance after the cutting abnormality is generated. It is shortened and can be re-disconnected with a little loss time. If the loss time before re-cutting is small, the temperature drop of the defective cutting part will be small, re-cutting will be easy, the cutting speed decrease at the start of re-cutting will be avoided, and high-efficiency cutting as a whole will be possible. .

Further, according to the present invention, since the image sensor can be installed remotely on the downstream side of the gas cutting torch, it is possible to avoid the thermal influence due to the cutting. Therefore, practically sufficient durability is guaranteed.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a block diagram showing a configuration example of a cutting control device for continuously cast slabs according to the present invention, and FIG. 2 exemplifies image processing contents for determining cutting abnormality in the same device. Here, (A) is a configuration diagram in the case where an image is divided into a plurality of area parts, (B) is a diagram showing an example of point distribution in which each area part is given a weight, and 4 is a slab automatic cutting Device 5, image sensor, 6 image processing device, 7
Is a judging device, 8 is a cutting control system, 9 is an area window,
10 is a score.

The image sensor 5 is installed downstream of the slab conveying line of the slab automatic cutting device 4 at an appropriate distance from the gas cutting torch 3 so that the slab cutting portion can be imaged.

That is, when the image sensor 5 picks up an image of the slab cutting portion, the image is displayed by the image processing device 6.
The areas of the splashed parts in the plurality of area windows 9 which have been subjected to the value conversion processing and are predetermined as shown in FIG. 2 (A) are obtained, and the area values are input to the determination device 7,
If the area value is equal to or greater than a preset threshold value, it is determined that the cutting is abnormal. Or, as shown in FIG. 2 (B),
Each area of the area window 9 of the image divided into a plurality of points has a score of 10, a high score is set in a place with a high abnormality frequency, and a low score is set in a normal region. In the case of this score system, when an abnormal splash occurs, the total score of the area of the splashed portion is calculated by the image processing device 6, the total score is input to the determination device 7, and the total score is preset. If the threshold value is exceeded, it is determined that the cutting is abnormal. The number of points in each area of the area window 9 can be changed depending on the size of the slab. However, the designated location of the area window 9 is always tracked before the start of cutting so that it is always at the torch flame position of the gas cutting torch.

When the judgment device 7 judges that the cutting is abnormal,
The disconnection abnormality signal is output to the disconnection control system 8. Immediately after the abnormal cutting signal is input, the cutting control system 8 switches the movement of the automatic slab cutting device 4 in the opposite direction, returns the gas cutting torch 3 to the defective position, and performs the cutting again.

Regarding the cutting of the slab, a dedicated area for shaving is determined in advance, and the presence or absence of the slab in the area is determined at the completion timing of cutting to determine whether the slab is completely cut or incompletely cut. Can be determined.

EXAMPLE The present invention is applied to an actual machine and a casting size of 187 to 335φ
When an abnormal splash occurs when cutting the billet of
As a result of setting the preset abnormal value (threshold value) to 40% within the area window, most cutting abnormalities could be detected. In addition, as a result of increasing the number of abnormal samples online to improve the accuracy of the area window of the splash scattering place at the time of cutting error, the cutting error detection accuracy becomes higher, and stable cutting operation can be performed online. became.

FIG. 3 compares the number of troubles due to abnormal cutting in the above embodiment with that of the conventional case, and it can be seen that by applying the present invention, operational troubles due to abnormal cutting and transport troubles of cast slabs can be almost avoided.

[0024]

As described above, according to the present invention, the splash generated in correspondence with the cutting state is arithmetically processed by the image sensor and the image processing, so that the cutting abnormality can be surely performed without any time delay. Since the automatic determination can be performed, it is possible to reliably cut the slab within a limited time, and it is possible to sufficiently cope with the speeding up of continuous casting. Further, since the image sensor for picking up the image of the cutting portion is installed at the remote side on the downstream side of the cutting torch, heat effect due to cutting is avoided, practically sufficient durability is guaranteed, and stable operation can be expected for a long period of time. Furthermore, a dedicated worker for monitoring is not required, and the number of personnel can be reduced.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration example of a cutting control device for continuously cast slabs according to the present invention.

2A and 2B are views exemplifying image processing contents for determining a cutting abnormality in the same apparatus, FIG. 2A is a configuration diagram when an image is divided into a plurality of area parts, and FIG. It is a figure which shows the example of score distribution which gave the weight to.

FIG. 3 is a diagram showing the number of troubles due to abnormal cutting in a second embodiment of the present invention in comparison with a conventional case.

FIG. 4 is a schematic view showing an example of a cutting operation of a continuously cast slab.

[Explanation of symbols]

1 slab 2 Conveyor roll 3 gas cutting torch 4 Automatic slab cutting device 5 image sensor 6 Image processing device 7 Judgment device 8 Cutting control system 9 area window 10 points

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ identification code FI G06T 7/00 G06F 15/62 400 (56) References JP-A-2-274355 (JP, A) JP-A-60-184467 ( JP, A) JP 58-209454 (JP, A) JP 61-4872 (JP, A) JP 58-202960 (JP, A) JP 58-163560 (JP, A) (58 ) Fields surveyed (Int.Cl. ⁷ , DB name) B22D 11/16 B22D 11/126 B23K 7/00 G06T 7/00

Claims (3)

(57) [Claims] 1. When a gas cutting machine is traversed with respect to a continuously cast slab and the slab is cut, an image sensor captures a splash scattering state during cutting of the slab and the images are displayed in a plurality of areas. The score is determined in advance according to the abnormal frequency for each area, and if the total score of each area of the splashing part during cutting is equal to or more than a predetermined threshold value, it is judged as abnormal cutting. A method for controlling cutting of a continuously cast slab, comprising: returning the cutting torch to at least a defective cutting position and performing cutting again from the returning position. 2. As a method of determining the cutting abnormality, an image taken by an image sensor is binarized to obtain an area of a splashed portion within a predetermined area, and the area value is preset. 2. The method for controlling cutting of a continuously cast slab according to claim 1, wherein a method of determining abnormal cutting when the threshold value is equal to or more than the threshold value is used. 3. A slab cutting machine, which is installed at a predetermined interval downstream of a slab conveying line of a slab automatic cutting device for cutting a slab by traversing a gas slicing torch with respect to a continuously cast slab while cutting the slab. An image sensor that captures the splash scattering state of the image and an image that divides the image captured by the image sensor into a plurality of areas, and calculates the total score of the splash scattered parts during cutting by the score determined for each area A processing device, an abnormality determination device that determines a cutting abnormality when the total score is equal to or more than a predetermined threshold value, and outputs an abnormality signal to the slab automatic cutting device, and the cutting torch when a cutting abnormality occurs. At least to a defective cutting position, and a control means for controlling the automatic slab cutting device so as to perform cutting again from the returning position. Cutting control device.