KR20030034944A - Apparatus and method for trimming of strip by using ultrasonic vibration - Google Patents

Abstract

PURPOSE: An apparatus and a method for trimming strip at the outlet side of continuous annealing process or at the outlet side of continuous pickling and oiling processes before cold rolling by using ultrasonic vibration are provided. CONSTITUTION: In a trimming apparatus(400) for trimming strip(403) by arranging a pair of knives(401,402) to one side of which a coupling body is fixed, and to the other side of which an idle spindle is fixed in such a way that the knives have horizontal clearance and vertical clearance, the apparatus for trimming strip is characterized in that an ultrasonic vibration unit for transmitting external ultrasonic vibration to the knifes through a fitting plate(406) of the coupling body(407) is installed on at least one knife out of the pair of knives, wherein the ultrasonic vibration unit comprises a vibrator(409) for generating ultrasonic vibration, a booster(410) for adjusting the amplitude of vibration generated, a horn part(411) for transmitting the ultrasonic vibration to the knives, a power supply(412) for supplying electricity, and a rotor(414) for preventing twisting of a power supply cable(413) by rotation.

Description

Trimming apparatus of strip using ultrasonic vibration and its method {Apparatus and method for trimming of strip by using ultrasonic vibration}

The present invention relates to a trimming device for strips, and more particularly, to an apparatus for trimming strips using ultrasonic vibration at the exit of a continuous annealing process or at the exit of a continuous pickling and oiling process before cold rolling.

The side trimming process of trimming both edge portions of the strip is performed to eliminate the required width margin of the demand before cold rolling, edge cracks of the hot rolled sheet which cause sheet breakage during rolling, and other defects of the edge portion. In addition, the side trimming process is performed on a width strict material having a high degree of demand for width at the exit of the continuous annealing process, and is performed to meet the demand width of the demand at the exit of the continuous pickling and oiling process. In addition, the trimming process is also performed in the slitter process of demanding demand for continuously dividing a strip of wide material into a predetermined width.

There are many side trimming processes and similar processes in the steel process as mentioned above, but summarized the prior art and problems with a focus on the side trimming process in the continuous cold rolling process as follows.

The role of the side trimming process in the continuous cold rolling process is to match the sheet width of the cold rolled sheet required by the demand, and also to prevent the breakage that may occur during cold rolling by removing the edge portion of the hot rolled sheet where cracks and other defects exist. It is. The side trimming device 100 currently used for this purpose consists of upper and lower circular knives 101 and 102 with horizontal clearance a and clearance b as shown in FIG. . Here, the horizontal clearance (a) means a gap in which the upper and lower circular knives (101, 102) are separated from each other in the horizontal direction, and the vertical clearance (b) is the upper and lower circular knives (101, 102) It means a lap overlapping each other in the vertical direction.

As the hot rolled sheet 103 continuously passes through the upper and lower circular knives 101 and 102 having horizontal and vertical clearances a and b, the edge portion of the hot rolled sheet 103 is cut by a certain amount. At this time, the upper and lower circular knives (101, 102) do not have its own driving force, it is rotated by the feed force of the hot rolled plate (103).

As shown in FIG. 2, that is, the edge portion of the hot rolled plate 203 is cut by shearing and tearing through the upper and lower circular knives 201 and 202. First, the knife 201, 202 shears the hot rolled sheet 203 by the set amount of vertical clearance b. Then, cracks 204 and 205 are generated by the rotational force of the knives 201 and 202 at the end portions of the shear deformation, that is, the ends where the knives 201 and 202 dig into the hot rolled plate 203. The cracks 204 and 205 generated at the ends of the upper and lower circular knives 201 and 202 are thus advanced to meet at the center of the cut surface of the hot rolled sheet 203 and finally cut.

In the cutting process as described above, the crack 204 formed by the upper circular knife 201 and the crack 205 formed by the lower circular knife 202 are simultaneously generated due to various work factors in the field. It is often the case that the center of the cut surface of 203 is encountered and cannot be cut. That is, the cracks 204 and 205 formed by the knives 201 and 202 deviate from each other, and the crack 204 generated at the upper portion penetrates to the lower end of the cut surface of the hot rolled plate 203, and the crack generated at the lower portion ( 205 penetrates to an upper cut surface of the hot rolled plate 203. Therefore, a sharp burr is formed at the top or the bottom in the thickness direction of the hot rolled plate 203.

The bur formed in this way damages many rubber rolls on the exit side of the side trimming device. In addition, the pieces of rubber that are torn off by the burrs are attached to the hot rolled sheets as they are cold rolled to cause surface defects. In addition, a sharp burr present in the hot rolled sheet causes cracks and defects during cold rolling. In particular, cracks and defects are generated in the work roll used for the first stand, and surface defects are generated in the strip by the work roll.

And the burr acts as a main factor which makes width reversal rolling impossible to roll regardless of strip width. That is, when the wide member is rolled after the narrow member is rolled, the defect mark generated on the work roll during the narrow member roll creates surface defects on the strip during the roll member of the member. Therefore, the current rolling is made in the order of rolling the narrow width material finally starting from the wide width material, which causes a lot of problems in product quality and logistics flow.

In addition, the conventional trimming device does not generate shear smoothly without any resistance by a predetermined vertical clearance amount, and the secondary shear phenomenon in which a crack occurs in the middle portion instead of the end of the knife due to the initial non-uniform shear force occurs. There is a problem.

Therefore, a method for reducing or eliminating burrs generated during side trimming has been proposed. That is, a method for optimizing the vertical and horizontal clearance according to the thickness, width and steel grade of the hot rolled sheet, which is a trimming material, changing the material of the trimming device, and sharp angles around the circular knives 301 and 302 as shown in FIG. 3. A method of reducing burrs by reducing the shear surface by processing grooves (SEAISI, Vol 1, 1997, New Trimming Method for burr-less trimming) has been proposed. However, the method is not only difficult to machine, but also promotes wear on sharp portions in actual application, and thus does not sufficiently achieve the desired purpose.

Therefore, the present invention has been made to solve the problems of the prior art as described above, by adding ultrasonic vibration to the knife to reduce the shear force and to concentrate the stress on the end of the knife to reduce the burrs generated during trimming or It is an object of the present invention to provide a trimming device and a method of stripping using ultrasonic vibration, which can be completely removed to prevent roll damage, to prevent surface defects of a product, to allow reverse reverse rolling in cold rolling, and to improve product error rate.

1 is a schematic diagram schematically showing a trimming apparatus of a strip according to the prior art,

FIG. 2 is a schematic diagram showing a cutting mechanism of a strip through the trimming device shown in FIG. 1;

3 is a schematic view showing another form of the knife of the trimming apparatus shown in FIG.

4 is a schematic diagram schematically showing an apparatus for trimming a strip using ultrasonic vibrations according to an embodiment of the present invention,

Figure 5 is a photograph comparing the structure of the cutting surface of the hot rolled sheet cut through each of the trimming apparatus of the prior art and the trimming apparatus of the present invention,

Figure 6 is a photograph comparing the fracture shape of the cut surface of the hot rolled sheet cut through each of the trimming device of the prior art and the trimming device of the present invention.

♠ Explanation of symbols on the main parts of the drawing ♠

400: trimming device 401, 402: knife

403: strip 407: assembly

409: vibrator 410: booster

411: horn 414: rotor

415: stud 416: amplifier

The trimming device of the present invention for achieving the above object is arranged to have a horizontal clearance and a vertical clearance, a pair of knives are fixed to the combination on one side and the idle spindle on the other side, of the pair of knives At least one knife is characterized in that the ultrasonic vibration device for transmitting the external ultrasonic vibration to the knife through the fitting plate of the combination.

In addition, the trimming method of the present invention is to trim the strip through the trimming device configured as described above, by operating the ultrasonic vibration device installed on the knife at the time of rotation of the pair of knives ultrasonic wave through the fitting plate of the assembly It is characterized by transmitting the vibration to the knife.

In the following, with reference to the accompanying drawings, a preferred embodiment of a strip trimming device and a method using ultrasonic vibration according to the present invention will be described in detail.

4 is a schematic diagram schematically showing an apparatus for trimming a strip using ultrasonic vibrations according to an embodiment of the present invention. As shown in FIG. 4, the side trimming apparatus 400 of the present invention is conventionally shown in FIG. 1 except that it is configured to apply ultrasonic vibration to the upper and lower circular knives 401 and 402 that are rotating continuously. The same as the side trimming device 100 of the.

As shown in FIG. 4, the side trimming device 400 of the present invention includes upper and lower circular knives 401, 402. These knives 401 and 402 are respectively coupled to idle spindles 404 which are idling according to the advancing force of the strip 403. At this time, only the knives 401 and 402 are not coupled to the spindle 404 alone, but the knives 401 and 402 are fitted to the spindle 404, respectively, followed by a pad ring 405 and a fitting plate. A fitting plate 406 is coupled to the bolt 408 by the combined assembly 407. The fitting plate 406 is made of aluminum.

According to the present invention, in order to apply ultrasonic vibration to the continuously rotating knives 401 and 402, the ultrasonic vibration of the ultrasonic vibrator described later by the fitting plate 406 of the assembly 407 is used. 402) is to be a medium to deliver.

The ultrasonic vibration device of the present invention includes a vibrator 409 for generating ultrasonic vibrations, a booster 410 for adjusting the amplitude of the generated vibrations, and a call for finally transmitting the ultrasonic vibrations to the knives 401 and 402. It consists of the on part 411, the power supply 412 which supplies electricity, and the rotor 414 etc. which prevent the electric supply cable 413 from twisting by rotation.

In order to couple the ultrasonic vibration apparatus of the present invention to the assembly 407, the fitting plate 406 is threaded to install a stud, and the stud 415 is coupled to the thread. In addition, the horn 411, which is an end portion of the ultrasonic vibrator and transmits vibration to the medium, also processes a thread and couples it to the stud 415. The ultrasonic vibration device coupled to the fitting plate 406 should rotate in the same manner as the knife 401 and 402 and the combination 407 for pushing the knife 401 and 402. Thus, the end of the ultrasonic vibration device is configured by the rotor 414 so that the cable 413 for supplying the power 412 is not twisted.

As such, the ultrasonic vibration device having the frequency and amplitude set by the amplifier 416 is continuously applied to the knives 401 and 402 while the ultrasonic vibration device is coupled to the assembly 407 and rotated. The frequency and amplitude of the amplifier 416 are transmitted to the vibrator 409 via the signal transmission cable 417, which is not twisted because it is connected to the vibrator 409 via the rotor 414. do. In addition, the frequency band of the ultrasonic wave applied from the amplifier 416 generally uses 15 to 20 kHz.

By continuously applying ultrasonic vibrations having a predetermined frequency to the knives 401 and 402 by such a method, the shear force decreases at the contact portion where the cut surfaces of the knives 401 and 402 and the strip 403 come into contact with each other. Stress concentration occurs at the ends of 401 and 402. Therefore, cracks are easily generated at the ends of the knives 401 and 402, respectively, and the cracks are easily advanced to form the cut surface of the strip 403. As a result, burrs are reduced or removed at the cut surface of the strip 403.

Then, the frequency band applied to the upper and lower knives 401 and 402 asymmetrically acts in a state where the vertical clearance amount is constantly set, so that cracks generated at the ends (edges) of the upper and lower knives 401 and 402 are provided. By controlling the behavior of the burr can be more effectively controlled.

That is, the present invention reduces the coefficient of friction between the knife 401, 402 and the cutting surface of the strip 403, which is a cutting object, by applying ultrasonic vibration of a predetermined frequency band to the knife 401, 402 continuously during trimming. Thereby, the shear force decreases, stress is concentrated at the ends of the knives 401 and 402 where the shear strain hook rack is generated, and the burrs generated at the upper and lower cutting planes of the strip are reduced by the secondary shear prevention or Removed.

5 illustrates that the structure of the cutting surface is different when ultrasonic vibration is continuously applied only to the upper circular knife in the side trimming process installed at the pickling tank outlet side of the actual continuous cold rolling process. That is, as shown in (a) of FIG. 5, when ultrasonic vibration is not applied, the structure of the cut surface is a roll over layer (501; roll over-the portion where the knife presses the strip purely at first) and the shear deformation layer 502 ) And the breaking layer 503 or the like (prior art). However, as shown in FIG. 5B, it can be seen that when the ultrasonic vibration is applied, only the shear deformation layer 504 and the breaking layer 505 appear without the roll over layer (invention). This proves the change in shear force at an early stage.

In addition, Fig. 6 is a comparison of the actual cutting surface when the ultrasonic vibration is applied and the non-applied, when the lower portion where the bur appears when the ultrasonic vibration is applied (Fig. 6 (b)-the present invention) is not applied [ Figure 6a (a)-prior art] can be seen that appear much dull. In FIG. 6, reference numeral 601 denotes a fracture form when no ultrasonic vibration is applied, and 602 denotes a fracture form when ultrasonic vibration is applied.

According to the present invention, ultrasonic vibration may be applied to only one of the upper and lower circular knives 401 and 402, or ultrasonic vibration may be applied to both of the upper and lower circular knives 401 and 402. Alternatively, asymmetric ultrasonic vibration can be applied.

As described in detail above, the apparatus for trimming a strip using the ultrasonic vibration and the method of the present invention add ultrasonic waves to the knife to reduce shear force and concentrate stress at the end of the knife to reduce or completely reduce burrs generated during trimming. By removing it, it is possible to prevent roll damage, to prevent surface defects of the product, to reverse roll rolling in cold rolling, and to improve the product error rate.

In the above description of the strip trimming device using the ultrasonic vibration of the present invention and the technical details of the method with the accompanying drawings, but this is illustrative of the best embodiment of the present invention is not intended to limit the present invention.

In addition, it is obvious that any person skilled in the art can make various modifications and imitations without departing from the scope of the technical idea of the present invention.

Claims (4)

In the trimming device for trimming the strip by arranging a pair of knives fixed to the combination on one side and the idle spindle on the other side to have a horizontal clearance and a vertical clearance, Trimming device, characterized in that the ultrasonic vibration device for transmitting an external ultrasonic vibration to the knife through at least one of the pair of knives through the fitting plate of the combination. The apparatus of claim 1, wherein the ultrasonic vibration device comprises: a vibrator for generating ultrasonic vibration, a booster for adjusting the amplitude of the generated vibration, a horn unit for finally transmitting ultrasonic vibration to the knife, and electricity. Trimming device comprising a power supply for supplying, and a rotor to prevent the electrical supply cable is twisted by the rotation. A pair of knives are fixed to one side and the idle spindle is fixed to the other side is arranged to have a horizontal clearance and a vertical clearance, the fitting plate of the combination to at least one knife of the pair of knives In the method for trimming the strip through a trimming device (trimming device) is installed is an ultrasonic vibration device for transmitting an external ultrasonic vibration to the knife through, And operating the ultrasonic vibration device installed in the knife when the pair of knives is rotated, thereby transmitting ultrasonic vibration to the knife through a fitting plate of the assembly. The trimming method according to claim 3, wherein when the ultrasonic vibrator is installed in the pair of knives, the ultrasonic vibration is symmetrically or asymmetrically added to the pair of knives.