JP2922403B2 - Method of detecting breakage of hammer - 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 detecting breakage of a dripping hammer when a dripping hammer removes dripping attached to a lower edge of a cut surface of a slab cut to a predetermined length by a torch. 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, so it is necessary to cut the slab into a length corresponding to the width of the heating furnace. As the cutting method, a torch cutting method using gas is generally employed because the slab is at a high temperature and the thickness of the cut portion is large.

When a slab is cut by a torch cut method, a torch drip mainly composed of slag adheres to a lower edge of a cut surface of the slab. This torch drip is less likely to be peeled off until the end of slab rolling in the subsequent process, and also affects the size and shape of the product and remains as a flaw in a high quality part, so it is necessary to remove the torch drip of the slab. Various methods have been proposed as a device for removing a torch sag of a continuously cast slab. Among them, a rotor type torch sag removing device is disclosed in Japanese Patent Application Laid-Open No. Hei 4-231154, which is relatively reliable.

As shown in FIG. 4, the apparatus comprises a rotor shaft 6 which can move up and down in a vertical direction of a slab 1 transfer line, a plurality of hammers 7 mounted around the rotor shaft 6, and a hammer 7. Is constituted by a support shaft 8 and a bearing 9 for rotatably supporting the shaft. When the rotor shaft 6 is rotated, the hammer 7 supported by the support shaft 8 is rotated in a state of being erected by centrifugal force. Next, the outer periphery of the hammer 7 with the rotor shaft 6 raised is raised so as to be at a position ΔH slightly above the horizontal pass line H on the lower surface of the slab 1, and the torch drip 11 is beaten off at the tip of the hammer 7 to be removed. is there.

[0005]

As described above, the operation of knocking down the torch drip 11 attached to the lower edge of the cut surface of the slab 1 moving on the transport path by the tip of the hammer 7 standing by the rotation of the rotor shaft 6 as described above. Is performed, if the tip of the hammer 7 breaks, the torch drip removal rate becomes worse.

Conventionally, whether or not the hammer 7 has been broken has been a situation where the hammer 7 itself is visually inspected one by one to check for breakage only after a large number of situations where the torch drip has not been removed. For this reason, since the torch drip 11 adheres to the lower edge of the cut surface of the slab 1 cast while the hammer 7 is broken, the operator must manually remove the remaining drip. There was a problem that it had to be done.

[0007] When a hot slab is directly sent from a continuous casting plant to a hot rolling plant, the hammer is actually broken despite the fact that sagging has already been performed on the information. As a result, it may happen that dripping remains on the slab. In this way, if the information does not match the actual information, dripping adheres to the slab and enters the heating furnace of the hot rolling factory, causing a problem of product defects.

[0008] The present invention solves the problems of the prior art,
It is possible to reliably detect breakage of the dripping hammer, thereby preventing the torch dripping adhered to the lower edge of the cut surface of the slab from being left unremoved, for example, it is possible to accurately determine whether or not to order a hot direct-feed slab. It is an object of the present invention to provide a method for detecting breakage of a dripping hammer.

[0009]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a dripping hammer swingably supported by a plurality of support shafts provided around a rotor shaft supported to be movable up and down. A drive motor for rotating a rotor shaft generated when removing dripping attached to a lower edge portion of a cut surface of a slab moving on a conveyance path by a tip of a hammer raised by rotation of the rotor shaft. And detecting a breakage of the sag removing hammer on the basis of the decrease in the current value.

[0010]

According to the present invention, when the tip of the hammer raised by the rotation of the rotor shaft knocks down the torch dripping from the lower edge of the cut surface of the slab, the current value of the drive motor rotating the rotor shaft is reduced by the change in the hammer. To detect breakage. Therefore, the break timing of the hammer can be accurately caught in a quantified state by observing the reduced change in the current value generated when the torch is hit.

Also, since it is possible to determine in advance whether or not a hot direct-feed slab command should be set, if a broken hammer is detected even if a command is set, the slab that has not been dripped is removed by changing the command. Can be reliably prevented from being rolled after being placed 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 using a lifting cylinder 2 on a transfer line of a slab 1.
And a plurality of hammers 7 attached 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 in a state of being erected by centrifugal force. Next, the outer periphery of the hammer 7 with the rotor shaft 6 standing up is raised so as to be slightly above the horizontal pass line H on the lower surface of the slab 1, and the tip of the hammer 7 knocks down the torch drip 11 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 rotating the rotor shaft 6 is measured using the automatic hammer breakage detecting device 4, and the breakage of the hammer 7 is detected based on the decrease in the measured current value. It is. For example, FIG. 2 shows a time-dependent change 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 sauce 11 is 1
It has risen to 50A.

On the other hand, FIG. 3 shows a torch sag attached to the lower edge of the cut surface of the slab 1 by the broken hammer 7.
In the case of hitting 11, the force of hitting the torch sag 11 is weakened due to the breakage of the hammer 7, so that the current value of the drive motor 3 has reached only 100A, which is significantly reduced as compared with 150A in FIG. You can see that there is. The breakage of the hammer 7 is detected by using the reduced 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 = 50 A). Current value difference Δ
If it is determined that the hammer 7 is broken when A exceeds the set value, the hammer breakage can be quantitatively detected. Thus, when the breakage of the hammer 7 is detected, the hammer breakage can be automatically warned using the speaker 12 installed in the central operation room 5 in accordance with a command from the automatic hammer breakage detecting device 4.

[0015]

As described above, according to the present invention, the state of the hammer can be quantitatively indicated by the current value generated when the hammer hits the sag. Therefore, the timing at which the hammer breaks can be immediately detected, and the replacement timing of the hammer can be determined. As a result, it is possible to prevent the mismatch between the information on the execution of the sag removal and the actual sag remaining of the slab as in the related art.

Further, when the order of the hot direct-feed slab has been set because the timing of the breakage can be accurately known, the slab is heated with the dripping attached by detecting the breakage of the hammer in advance. The effect is obtained that it is possible to prevent rolling and rolling as it is.

[Brief description of the drawings]

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

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

FIG. 3 is a diagram showing a temporal change of a current value of a drive motor when a hammer breaks.

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

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Slab 2 Lifting cylinder 3 Drive motor 4 Automatic hammer breakage detecting device 5 Central operating room 6 Rotor shaft 7 Hammer 8 Support shaft 9 Bearing 10 Sag removal device 11 Torch drip 12 Speaker

Continuation of front page (56) References JP-A-61-236412 (JP, A) JP-A-55-14136 (JP, A) JP-A-5-305406 (JP, A) JP-A-3-110050 (JP) , A) JP-A-5-177311 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B22D 11/126 B23K 7/10 B25D 15/00

Claims (1)

(57) [Claims] 1. A method for detecting breakage of a dripping hammer supported swingably on a plurality of support shafts provided around a rotor shaft supported up and down freely, the method comprising the steps of: The breakage of the dripping hammer based on the change in the current value of the drive motor that rotates the rotor shaft, which occurs when removing the dripping attached to the lower edge of the cut surface of the slab moving on the transport path by the tip of the hammer A method for detecting breakage of a dripping hammer, which is characterized by detecting.