JPH08150453A - Method for cutting off continuously cast slab - Google Patents

Abstract

PURPOSE: To surely detect the position of side end surfaces of a cast slab by using an ITV camera under bad condition, in which steam, splash, hume, etc., exist in a continuously cast slab. CONSTITUTION: The cast slab 3 continuously carried is photographed with the ITV camera 26 and a video signal of the cast slab 3 is inputted to a picture data operation processor 30. Picture signal is divided into picture elements 34 in this operation processor 30. Luminance in each division is calculated to decide the position of the side end surface of the cast slab with the degree of the luminance. This decided position is inputted into a torch positional control device and a gas melt-cut-off torch is shifted to the decided position to start the cut-off work. By this method, the cut-off trouble of the cast slab 3 caused by the defective detection of the side end surface of the cast slab can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention holds a slab that is continuously conveyed from a continuous casting device along a slab conveying path and moves the gas cutting machine synchronously to move the gas at a predetermined cutting point of the slab. The present invention relates to a method of moving a fusing torch along a transverse direction from a side end surface of a slab and cutting the continuously cast slab.

[0002]

2. Description of the Related Art Generally, as shown in FIG. 6, in a curved type continuous casting apparatus 40, the molten steel in a ladle 41 is supplied to a tundish 42, and a dipping nozzle 44 provided at an outlet of the tundish 42.
It is injected into the mold 45 via. On the outlet side of the mold 45, a large number of support rolls 46 for supporting the slab 3 are arranged and a spray cooling zone 47 for cooling with water spray is installed.

A pinch roll 48 and a straightening roll 49 are arranged in the direction of extracting the slab of the spray cooling zone 47, and a gas cutting machine 1 is installed on the downstream side of the slab, and the slab cut by the gas cutting machine 1 is installed. 3 is carried out by the table roller 2 to the rolling mill which is the next step. The withdrawal speed of the slab 3 is a low speed of 1 to 3 m / min, but it is in the red hot state of 600 to 800 ° C even in the state of being left to cool.

As shown in FIGS. 7 and 8, the gas cutting machine 1 of the continuous casting apparatus is equipment for cutting the slab 3 conveyed by the table roller 2 to a fixed length, and the electric motor 4A at the rear of the carriage 27, A cart moving device 4 including a transmission mechanism 4B and the like is provided. By driving the trolley moving device 4, the gas cutting machine 1 travels on the rail 6 via the wheels 8.

At the center of the carriage 27, there is provided a clamp device 5 capable of moving the gas cutting machine 1 in synchronism with the cast piece 3 by holding the cast piece 3 from both sides by the clamp claws 5A. Further, a torch moving base 7 is arranged on the left and right in the front part of the carriage 27, and a forward / reverse driving motor 11 is arranged on the torch moving base 7 to drive the driving motor 11. By doing so, the torch moving base 7 is movable left and right along the guide rod 9 supported by the carriage 27 via the bracket 12. On the front surface of each torch moving base 7, a gas fusing torch 10 is installed facing downward.

As shown in FIG. 9, a rack 13 is provided on the front surface of the guide rod 9, and a pinion 14 built in the torch moving base 7 meshes with the rack 13. The pinion 14 has a large gear 15 and the large gear 15 has a small gear.
16 mesh with each other, and the rotating shaft 11A of the small gear 16 is connected to the drive motor 11 to form a traverse / measuring mechanism 28.

A pinion pulley 17 coaxially fixed to the pinion 14 and a two-groove pulley coaxially fixed to the gear 15 are provided.
A transmission belt 19 is stretched over one groove of 18, and a measurement belt 21 is provided between the other groove of the two-groove pulley 18 and a measurement pulley 20 connected to a rotation speed / distance conversion device (not shown). Has been passed over. When the drive motor 11 is rotated in the normal direction or the reverse direction, the small gear 16 rotates via the rotating shaft 11A, which causes the pinion 14 to rotate via the large gear 15. As a result, the pinion 14 moves along the rack 13 on the fixed side, whereby the torch moving base 7 equipped with the gas fusing torch 10 can move freely along the guide rod 9 in either the left or right direction. At this time, the moving distance of the gas fusing torch 10 through the rack 13 due to the rotation of the pinion 14 is such that the measuring pulley 20 is rotated via the pinion pulley 17, the transmission belt 19 and the measuring belt 21 which are coaxially fixed to the pinion 14. It is measured by transmitting the rotation speed to a rotation speed / distance conversion device and converting the rotation speed into a distance.

As shown in FIG. 10, an end face detection rod 22 for detecting the side end face of the slab 3 is swingably suspended on the side surface of the torch moving base 7 via a pin seat 22B. Drive the drive motor 11 to move the torch moving base 7 from the standby position to the slab 3
And moves it along the guide rod 9 so as to approach.
When the tip of the end face detection rod 22 comes into contact with the side end face of the slab 3 and is pushed, the L-shaped other end 22 of the end face detection rod 22 is pushed through the pin seat 22B.
A kicks the limit switch 23, which operates the limit switch 23 to detect the position of the side end surface of the cast slab 3.

When cutting the cast slab 3 coming out of the continuous casting apparatus, the cast slab 3 is measured using a cast slab length measuring device (not shown). When the cutting start signal is output from the slab length measuring device to the gas fusing machine 1, the carriage 27 that constitutes the gas cutting machine 1
The clamp claw 5A of the clamp device 5 arranged in the
It is pressed to both side surfaces of the slab and moved in the downstream direction in synchronization with the slab 3. Subsequently, the drive motor 11 is driven to move the torch moving base 7 in the direction of approaching the slab 3 from the standby position. When it is detected by the limit switch 23 that the tip of the end face detection rod 22 comes into contact with the side end face of the slab 3, the fuel gas and the oxygen gas are supplied to the gas fusing torch 10 at that time to ignite and cut the slab 3 for gas cutting. To start.

[0010]

The means for detecting the side end face of the cast slab 3 by the end face detection rod 22 swingably arranged on the side surface of the torch moving base 7 is such that the end face detection rod 22 is provided with a pin seat 22B. Since it is supported by the rotary shaft, mechanical backlash due to wear of the rotary shaft, thermal deformation, and mechanical changes such as corrosion easily occur, and it becomes gradually difficult to accurately detect the side end surface of the cast slab 3. In addition, after the end face detection rod 22 comes into contact with the side end face of the slab 3 and escapes with the pin seat 22B as a fulcrum, the limit switch
There is a drawback in using 23 because it has a complicated structure and is fragile and has a short life.

As a side end face detecting means of the cast slab 3, as shown in FIG. 11, the guide rod 9 is driven by the drive motor 11.
Laser-type end face detector on the torch moving table 7 that moves along the
It is known that 24 are arranged. Laser type facet detector
The reference numeral 24 irradiates a laser beam 35 while moving the torch moving table 7 in a direction approaching the slab 3 from the standby position, and the projected laser beam 35 hits the side end surface of the slab 3 and then is reflected. The side end surface of the cast piece 3 is detected by receiving the laser beam 35.

Unlike the above-mentioned end face detection rod 22, the laser type end face detector 24 does not have a mechanism for directly contacting the slab 3, so that mechanical deterioration does not occur. However, since water vapor, splash, fume, or the like exists near where the gas cutting machine is installed, it impedes the transmission of the laser beam 35 emitted from the laser type end face detector 24. Therefore, there is a fatal defect that it is difficult to reliably detect the side end surface of the slab 3.

Therefore, in the actual operation, when the end face detection rod or the laser type end face detector fails to detect the end face on the slab side, the operator can directly visually observe the cast slab reflected on the industrial television. The position of the end face on one side was decided, and the slab cutting had to be started manually. Therefore, an operator is required for monitoring when the detection fails. In particular, it is often difficult to identify the side end surface of the slab only by the image displayed on the industrial television, and in the end, it was the fact that we had to rely on direct visual inspection.

The present invention solves such a problem, and reliably detects the side end surface of a cast piece without causing mechanical failure even under bad conditions such as water vapor, splash, fume, etc., and gas fusing An object of the present invention is to provide a method for cutting a continuously cast slab capable of automatically starting cutting with a torch.

[0015]

SUMMARY OF THE INVENTION To achieve the above object, the present invention holds a slab continuously conveyed from a continuous casting device along a slab conveying path, and synchronously moves a gas cutting machine. While cutting the continuous casting slab by moving the gas fusing torch along the transverse direction from the side end surface of the slab at a predetermined cutting point of the slab, the continuously conveyed slab is transferred by an industrial television camera. Shooting, input the video signal of the slab into the image data arithmetic device, to determine the position of the side end surface of the slab by performing a calculation by luminance analysis based on the image signal of the slab in this arithmetic device, The continuous side casting characterized by inputting the determined side end surface position signal of the slab to a torch position control device and moving the gas fusing torch to the determined side end surface position of the slab according to a position command from the control device. Cutting slab It is the law.

[0016]

According to the present invention, the continuously conveyed slab is photographed by an industrial television camera, and the video signal of the slab is applied to an image data arithmetic unit to perform calculation by luminance analysis based on the image signal of the slab. Thus, the position of the side end surface of the slab can be accurately detected. As a result, it is possible to reliably determine the cutting start point of the slab side end by the gas fusing torch.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. In the embodiment of the present invention, the same parts as those of the conventional example described with reference to FIGS. 6 to 11 are designated by the same reference numerals, and duplicate description will be omitted. As shown in FIG. 4, a truck 27 that constitutes the gas cutting machine 1 that travels on the rails 6 via the wheels 8.
A carriage moving device 4 is provided at the rear part, a clamp device 5 is provided at the center part, and a gas fusing torch 10 is provided at the front part.
The gas fusing torch 10 is supported downward on the front surface of the torch moving base 7 which is movable along the guide rod 9.

As shown in FIG. 5, the torch moving base 7 is a slab 3
Are arranged on both sides of the
By driving 11, the rack 13 and the gears such as the pinion 14 and the measuring pulley 20, the measuring belt 19 and the like are traversed via the traversing / measuring mechanism 28 and the traverse distance of the gas fusing torch 10 is described. Is measured as before.

In the present invention, an industrial television camera (hereinafter referred to as an ITV camera) 26 is attached to the tip of a support beam 25 protruding forward from the upper portion of a dolly 27, and a casting that moves near the gas fusing torch 10 is attached. The side end surface of the piece 3 can be photographed. When cutting the slab 3 coming out of the continuous casting device, the slab 3 is measured using a slab length measuring device (not shown). When a cutting start signal is output from the slab length measuring device to the gas fusing machine 1, the clamp claws 5A of the clamp device 5 arranged on the carriage 27 constituting the gas slicing machine 1 are crimped to both side surfaces of the slab 3. Then, it is moved in the downstream direction in synchronization with the slab 3.

In the present invention, the ITV camera 26 in which the cast slab 3 which is moving in a red-hot state at a temperature of 600 to 800 ° C. on the table roller 2 is attached to the carriage 27 through the support beam 25
Then, the image signal is input from above to the image data arithmetic processing unit 30 of the image processing system 29 as shown in FIG. In the image data arithmetic processing unit 30, for example, an image displayed on an industrial television monitor (ITV monitor) 33 is divided into 200 × 100 pixels 34, and the image luminance for each division is analyzed to obtain the obtained luminance. The size is converted into a numerical value as shown in FIG. 2 and displayed on the ITV monitor 33.

That is, in FIG. 2, the numerical values 9 to 13 are
It's small, so it's in the low temperature range.
Therefore, the high temperature area (red hot part where the slab is present) is shown.
Therefore, the boundary between the two regions indicates the side end of the slab 3,
As a result, in the image processing system 29, the position of the end surface on the slab side is
To determine. In this way, the position of the side end surface of the slab 3 is determined
Then, this position signal is set in the disconnection control sequencer 31.
It is input to the torch position control device 32 which is embedded. This
In the torch position control device 32 of, as shown in FIG.
Gas fusing torches on both sides that are always waiting at a fixed position 10,
Distance L between 10₁Is known, the distance L₁Number of pixels N
₁And the position of both ends of the slab 3 and the gas fusing torches 10 on both sides.
Distance L₂, L₃Number of pixels N₂, N₃Each with
Distance L₂= L₁N₂/ N₁And distance L₃= L ₁N₃/
N₁Is calculated. Gas fusing torch 10 obtained by this calculation
Movement distance L₂, L₃Drive the driving motor 11 based on
By doing so, the torch moving base 7 is switched to the gas by the cutting start signal.
The slab 3 is moved toward the cutting machine 1 in synchronism with the cutting machine 1.
At this time, the torch moving base 7 moves along the guide rod 9.
The distance to be measured is the number of rotations / distance through the measurement pulley 20 shown in FIG.
It is measured by a separation conversion device.

The moving distance of the torch moving base 7 measured is L
_2, soon becomes L ₃ stops driving motor 11, whereby the gas blown torch 10 as shown in FIG. 3 (B)
Is aligned with the position of the side end surface of the slab 3, and the gas fusing torch 10 is immediately supplied with fuel gas and oxygen gas and ignited to start fusing from both sides of the slab 3. When the cutting by the gas fusing torch 10 approaches the center part from both sides of the slab 3, one of the gas fusing torches 10 is returned to the standby position, and the other gas fusing torch 10 melts the remaining central part to finish the cutting work. To do.

In the conventional method, the defective rate of detection of the end face on the slab side by the end face detection rod was 0.05%.
It was able to be drastically reduced to%.

[0024]

As described above, according to the present invention, I
The side end face position of the slab is determined based on the calculation by the brightness analysis in the image data arithmetic processing device and the image signal taken by the TV camera, so that it is possible to overcome the existing bad conditions such as steam, splash, fume, etc. without fail. The slab-side end face position can be determined.

Since the slab is photographed by the ITV camera as a starting point, mechanical failure is unlikely to occur, stable measurement is possible, and stable cutting of the continuously cast slab is achieved.

[Brief description of drawings]

FIG. 1 is a flow chart showing a procedure of the present invention.

FIG. 2 is a luminance analysis of image data of a cast piece according to the present invention,
It is explanatory drawing which shows the example shown by a numerical value.

FIG. 3 is an explanatory diagram showing a positional relationship between an end surface of a cast slab according to the present invention after determining a side end surface thereof and a gas fusing torch.

FIG. 4 is a side view showing an apparatus according to the present invention.

FIG. 5 is a perspective view showing an apparatus according to the present invention.

FIG. 6 is a side view showing an outline of a conventional continuous casting device.

FIG. 7 is a side view showing a conventional gas cutting machine.

FIG. 8 is a plan view showing a conventional gas cutting machine.

FIG. 9 is a plan view showing a traversing / measuring mechanism for traversing a torch moving table including a conventional gas fusing torch and measuring a moving distance.

FIG. 10 is a perspective view showing a torch moving base provided with a conventional end face detection rod.

FIG. 11 is a perspective view showing a torch moving base provided with a conventional laser type end face detector.

[Explanation of symbols]

 1 Gas cutting machine 2 Table roller 3 Cast slab 4 Cart moving device 5 Clamping device 6 Rail 7 Torch moving table 8 Wheels 9 Guide rod 10 Gas fusing torch 11 Drive motor 12 Bracket 13 Rack 14 Pinion 15 Large gear 16 Small gear 17 Pinion Pulley 18 Two-groove pulley 19 Transmission belt 20 Measuring pulley 21 Measuring belt 22 Edge detection rod 23 Limit switch 24 Laser edge detector 25 Support beam 26 Industrial TV camera 27 Cart 28 Traverse / measuring mechanism 29 Image processing system 30 Image data calculation Processor 31 Cutting sequencer 32 Torch position controller 33 Industrial TV monitor 34 Pixels 35 Laser beam

Claims (1)

[Claims] 1. A gas fusing torch of a slab is cut at a predetermined cutting point of a slab while holding a slab continuously conveyed from a continuous casting device along a slab conveying path and moving the gas cutter synchronously. In a method of cutting a continuously cast slab by moving along a transverse direction from a side end surface, the continuously conveyed slab is photographed by an industrial television camera, and a video signal of the slab is sent to an image data arithmetic device. The position of the side end face of the slab is determined by inputting and calculating by brightness analysis based on the image signal of the slab with this arithmetic device, and the determined side end face position signal of the slab is torch position control device. And moving the gas fusing torch to the determined side end face position of the slab according to a position command from the control device.