JPH07116800A - Method for detecting breaking of hammer for removing roll over - Google Patents

Abstract

PURPOSE:To enable automatic detection of the breaking of a hammer for removing roll over of a rotary device for removing the roll over, which is stuck to the lower edge of the cut section of a slab. CONSTITUTION:The breaking of a hammer 7 for removing roll over is detected based on such decreasing change in the electric current of a driving motor 3 for rotating a rotor shaft 6 that is generated when the torch roll over 11 stuck to the lower edge of the cut section of a slab 1 is knocked down by the hammer 7 that is provided around the rotor shaft 6 in order to remove the roll over. Thus, the timing to replace the hammer 7 is decided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sag removing hammer breakage detecting method for removing a sag attached to a lower edge of a cutting surface of a slab cut to a predetermined length by a torch with a sapping removing hammer. is there.

[0002]

2. Description of the Related Art A slab manufactured by continuous casting is reheated in a heating furnace before being rolled in the next step, and therefore it is necessary to cut it into a length according to the width of the heating furnace. As this cutting method, a torch cutting method using gas is generally adopted because the slab has a high temperature and the thickness of the cut portion is large.

When the slab is cut by the torch cutting method, a torch sag containing slag as a main component adheres to the lower edge of the cut surface of the slab. This torch sag is less likely to be peeled off until the end of slab rolling in the subsequent process, and it affects the size and shape of the product and remains as a flaw in the high quality part, so it is necessary to remove the torch sag. Various methods have been proposed as a torch sag removing device for continuously cast slabs, but a rotor type torch sag removing device is disclosed in Japanese Patent Laid-Open No. 4-231154 as a device having relatively high reliability.

As shown in FIG. 4, this apparatus has a rotor shaft 6 which can be vertically moved up and down along a transportation line of a slab 1, a plurality of hammers 7 mounted around the rotor shaft 6, and a hammer 7. It is composed of a support shaft 8 for rotatably supporting and a bearing 9. When the rotor shaft 6 is rotated, the hammer 7 supported by the support shaft 8 is rotated while being erected by the centrifugal force. Next, the outer periphery of the hammer 7 where the rotor shaft 6 is erected rises to a position ΔH slightly above the horizontal pass line H on the lower surface of the slab 1, and the torch sag 11 is knocked off at the tip of the hammer 7 to remove it. is there.

[0005]

The work of knocking off the torch sag 11 attached to the lower edge of the cut surface of the slab 1 moving on the conveying path by the tip of the hammer 7 erected by the rotation of the rotor shaft 6 as described above. If the tip portion of the hammer 7 is broken during the operation, the torch sag removal rate becomes poor.

Conventionally, whether or not the hammer 7 is broken has been a situation in which the hammers 7 themselves are visually inspected one by one to check the presence or absence of breakage only after the state in which the torch drip has not been removed frequently occurs. For this reason, since the torch sag 11 is attached to the lower edge of the cut surface of the slab 1 cast while the hammer 7 is broken, the worker must remove the remaining sag by manual work. There was a problem that it had to be.

Further, when the hot slab is directly sent from the continuous casting plant to the hot rolling plant, the hammer is actually broken even though the information indicates that the slab has been removed. Because of this, it may happen that the slab still has a drip. If the information and the actual information do not match with each other in this way, the slab will be sagged and will enter the heating furnace of the hot rolling mill again, causing a product defect.

The present invention solves the above problems of the prior art,
It is possible to reliably detect breakage of the sagging hammer, thereby preventing removal of torch sagging left on the lower edge of the cut surface of the slab, and for example, to accurately determine whether or not to make a command for a hot direct feed slab. It is an object of the present invention to provide a method for detecting breakage of a sagging hammer.

[0009]

SUMMARY OF THE INVENTION To achieve the above object, the present invention is directed to a sagging hammer that is swingably supported by a plurality of support shafts provided around a rotor shaft that is vertically movable. And a drive motor for rotating the rotor shaft, which is generated when removing sag adhering to the lower edge of the cut surface of the slab moving on the transport path by the tip of the hammer erected by the rotation of the rotor shaft. Is a method for detecting a breakage of a sagging hammer, which is characterized by detecting a breakage of the sagging hammer based on a reduction change of the current value.

[0010]

In the present invention, the hammer is caused by the change in the current value of the drive motor for rotating the rotor shaft which is generated when the torch drop adhering to the lower edge of the cut surface of the slab is knocked down by the tip of the hammer erected by the rotation of the rotor shaft. Detects breakage. Therefore, it is possible to accurately catch the breakage timing of the hammer in a quantified state by observing the reduction change in the current value that occurs when the hammer hits the torch.

Further, since it is possible to judge in advance whether a command for a hot direct slab should be formed, if a breakage of a hammer is detected even if a command is formed, the slab that has not been sagged is removed by changing the command. It is possible to reliably prevent problems such as rolling the steel after putting it in a heating furnace.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, a rotor shaft 6 that can be vertically moved up and down by using an elevating cylinder 2 on a slab 1 transfer line.
A plurality of hammers 7 are mounted around the rotor shaft 6, a support shaft 8 for rotatably supporting the hammers 7, and a bearing 9. When the rotor shaft 6 is rotated, the hammer 7 supported by the support shaft 8 is rotated while being erected by the centrifugal force. Next, the outer peripheral portion of the hammer 7 that erects the rotor shaft 6 is lifted to a position slightly above the horizontal pass line H on the lower surface of the slab 1, and the torch sag 11 is knocked off at the tip of the hammer 7 to remove it. This is the same as the conventional example shown in FIG.

In the present invention, the current value of the drive motor 3 for rotating the rotor shaft 6 is measured by using the automatic hammer breakage detection device 4, and the breakage of the hammer 7 is detected based on the reduction change of the measured current value. Is. For example, FIG. 2 shows the change over time in the current value when the torch sag 11 attached to the lower edge of the cut surface of the slab 1 is hit by a normal hammer 7 without breakage. While the current value of the drive motor 3 when the rotor shaft 6 is rotating is 50 A (ampere),
The current value when the hammer 7 hits the torch 11 is 1
It has risen to 50A.

On the other hand, as shown in FIG. 3, the torch sagging attached to the lower edge of the cut surface of the slab 1 by the hammer 7 which has broken.
When hitting 11, the breaking force of the hammer 7 weakens the force to hit the torch drop 11, so the current value of the drive motor 3 reaches only 100A, which is much lower than 150A in Fig. 2. I know that The breakage of the hammer 7 is detected by utilizing the reduction change of the current value of the drive motor 2 shown in FIGS. 2 and 3 thus obtained, that is, the difference (ΔA = 150-100 = 50A), Difference in current value Δ
If A is equal to or larger than the set value, it is possible to quantitatively detect the breakage of the hammer by determining that the breakage of the hammer 7 has occurred. Thus, when the breakage of the hammer 7 is detected, it is possible to automatically warn the breakage of the hammer by using the speaker 12 installed in the central operation room 5 according to a command from the automatic hammer breakage detection device 4.

[0015]

As described above, according to the present invention, the state of the hammer can be quantitatively shown by the current value generated when the hammer hits the sag. Therefore, the timing at which the hammer is broken can be immediately detected, and the timing for replacing the hammer can be determined. As a result, it is possible to prevent inconsistency due to the droop removal execution information and the actual slab droop remaining as in the conventional case.

Further, when the instruction of the hot direct feed slab has been set because the timing of breakage can be accurately known, the slab remains heated and the slab remains sagging by recombining the instructions in advance by detecting the breakage of the hammer. It is possible to obtain an effect that it is possible to prevent the sheet from being rolled into a rolling state.

[Brief description of drawings]

1 is a schematic side view showing an apparatus according to the present invention.

FIG. 2 is a diagram showing a change over time in a current value of a drive motor when a hammer is normal.

FIG. 3 is a diagram showing a change over time in a current value of a drive motor when a hammer is broken.

FIG. 4 is a schematic side view showing an apparatus according to a conventional example.

[Explanation of symbols]

 1 Slab 2 Lifting Cylinder 3 Drive Motor 4 Automatic Hammer Breakage Detection Device 5 Central Control Room 6 Rotor Axis 7 Hammer 8 Support Axis 9 Bearing 10 Dag Removal Device 11 Torch Dull 12 Speaker

Claims (1)

[Claims] 1. A method for detecting breakage of a sagging hammer that is swingably supported by a plurality of support shafts provided around a rotor shaft that is vertically movable, the method being upright by rotation of the rotor shaft. Due to the change in the current value of the drive motor rotating the rotor shaft, which occurs when removing the sag adhering to the lower edge of the cutting surface of the slab moving on the transport path by the hammer tip, the sagging hammer is damaged. A method for detecting breakage of a sagging hammer, which is characterized by detecting.