KR20100071761A - In-line induction heating apparatus and method of in-line induction heating by using the same - Google Patents

Abstract

PURPOSE: An inline induction heater and an inline induction heating method using the same are provided to prevent strip breakage or rolling oil firing and enable high-speed warm rolling of magnesium alloy sheets. CONSTITUTION: An inline induction heater comprises an induction heating unit(20) which is movable to keep in uniform position with respect to the widthwise position of an object which is measured by a widthwise position measuring device(10). The induction heating unit comprises an induction heating coil(2) which is installed on the upper and lower sides of the object and able to rotate, and a shield plate(4) which is located between the induction heating coil and the edge of the object to block heat transfer from the induction heating coil to the edge.

Description

IN-LINE INDUCTION HEATING APPARATUS AND METHOD OF IN-LINE INDUCTION HEATING BY USING THE SAME}

The present invention relates to an induction heating apparatus and an induction heating method using the same. More specifically, the present invention relates to an inline induction heating apparatus used for high speed warm rolling of a magnesium alloy and an inline induction heating method using the same.

Magnesium alloy has excellent machinability, high vibration damping ability, excellent absorbency against vibration and shock, excellent electromagnetic shielding properties, light weight, high specific strength, and can be formed into a thin plate in terms of processing.

Therefore, in recent years, the demand is expanding widely in the technical field which requires not only the case parts of a computer, a camera, a mobile phone, but also a traditional metal plate, such as an automobile.

Most magnesium alloys, except for a few, such as magnesium-lithium (Mg-Li), have an atomic structure of HCP. Therefore, the cold rolling is possible to reduce the rate is very low, most of the plate is produced by the hot rolling of 150 to 400 degrees Celsius.

Because magnesium alloys have very high thermal conductivity and low specific heat, they are easily deprived of heat and, in the case of thin plates, they are cooled by tens of degrees in seconds, even if they are heated just before rolling, and in-line heating in the mill is essential. For mass production, it is advantageous to roll the plate in the form of a coil rather than a sheet.

The method of rolling a magnesium alloy sheet by in-line heating in the form of a coil has been possible only with low speed rolling of 15 mpm or less. Induction heating device is essential for supplying a large amount of heat required for high speed warm rolling. Induction heating device has various possibilities of non-uniform heating, and it supplies a large amount of heat to the plate immediately before rolling, and uniformly varies the width direction of the plate. There is a great difficulty in controlling. Furthermore, it was more difficult to accurately match the process control conditions of the rolling mill itself with temperature changes such as rapid heating and cooling, so that high speed rolling was not practical.

The induction heating technology can be classified into longitudinal flux induction heating (LFIH) and transverse flux induction heating (TFIH) .LFIH heating requires a very high frequency of very high frequency current and low heating efficiency for thin plates. TFIH type heating has become common due to problems that can damage the heating coil in emergency situations such as coil breakage.

However, TFIH heating has another problem: the degree of heating of the sheet is different depending on the shape and position of the coil, and the edges may be overheated.

Specifically, if the plate has a temperature deviation in the width direction, even when subjected to the same pressing load, the high temperature is pressed a lot and the low temperature is pressed a little so that the plate is abnormally rolled into a wave shape, and eventually cracks and breakage are caused. Will cause. In addition, in the rolling of magnesium alloy sheet, minute edge cracks are often generated.The current induced by the induction heater is concentrated in sharp parts of the cracks, so that the parts are broken due to instantaneous melting and plate breakage or ignition of rolling oil. It could cause a safety accident.

Due to these technical problems, high-speed warm rolling was virtually impossible for magnesium alloy sheet coils, which makes it difficult to increase production, and thus the price of magnesium alloy sheet is excessively high and has been a great technical barrier for practical use.

As described above, the matters described in the "Background art" are intended to help the understanding of the background of the present invention, and the technology described in this part is not necessarily the prior art, and is not known in the art, such as the technology falling within the protection scope of the present invention. Can be.

It is a first object of the present invention to provide an inline induction heating apparatus that enables high speed warm rolling, which can solve the above problems.

It is a second object of the present invention to provide an inline induction heating method using the above-described inline induction heating apparatus.

According to an embodiment of the present invention for achieving the first object, the in-line induction heating apparatus is a width direction position measuring device for measuring the width direction position of the heating target plate, and the width of the heating target plate measured through the above-described measuring device And an induction heating unit that is movable to maintain a constant position relative to the directional position.

The induction heating unit may include an induction heating coil rotatably provided at upper and lower portions of the plate to be heated. The induction heating unit may further include a shielding plate positioned between the upper and lower induction heating coils and the edges of the heating target plate to partially shield heat applied to the edges from the induction heating coils. The shielding plate may be water cooled. The shielding plate may be horizontally movable in the width direction perpendicular to the movement of the plate to be heated. The induction heating coil and the shielding plate may be provided to be movable in the vertical direction perpendicular to the surface of the plate to be heated. It may further comprise a frame defining the outside of the induction heating unit. The frame may be a reference for movement of the induction heating coil and the shield plate. The induction heating unit may further include an entrance thermometer measuring the temperature before the plate to be heated passes the induction heating coil and an exit thermometer measuring the temperature after the plate to be heated passes the induction heating coil. The width position measurer may be a center position control (CPC), edge position control (EPC) or laser sensor. The plate to be heated may include magnesium.

According to an embodiment of the present invention for achieving the second object, the in-line induction heating method to provide an induction heating coil in the upper and lower portions of the heating target plate moving along the movement path and to rotate the induction heating coil Heating the plate.

A shielding plate may be provided between the edge portion of the plate to be heated and the vertical induction heating coil, respectively, to block heat provided from the induction heating coil at the edge portion. The shielding plate may be horizontally movable in the plate width direction perpendicular to the direction in which the plate to be heated moves. The shield can be water cooled. The induction heating coil and the shielding plate may be movable up and down in a direction perpendicular to the surface of the plate to be heated. The temperature of the plate to be heated before and after the heating caused by the induction heating coil may be measured by the entry thermometer and the exit thermometer to adjust the current provided to the induction heating coil. The degree of movement when moving in the vertical plate width direction based on the movement path of the heating target plate can be measured by using the width direction measuring device to correspond the position of the induction heating unit to the movement in the width direction of the heating plate. have. The width position measurer may be a center position control (CPC), edge position control (EPC) or laser sensor. The heating target plate may include magnesium.

According to the present invention, it is possible to perform uniform heating to minimize the temperature variation in the width direction while providing a sufficient amount of heat and efficiency for high speed warm rolling, and to prevent overheating of the edges to prevent plate breakage or rolling oil ignition. Warm rolling can be enabled.

Hereinafter, embodiments of an inline induction heating apparatus and an inline induction heating method using the same will be described with reference to the accompanying drawings. I) The shapes, sizes, ratios, angles, numbers, operations, and the like shown in the accompanying drawings may be changed to be rough. ii) Since the drawings are shown with the eyes of the observer, the direction or position for describing the drawings may be variously changed according to the positions of the observers. iii) The same reference numerals may be used for the same parts even if the reference numbers are different. iv) When 'include', 'have', 'consist', etc. are used, other parts may be added unless 'only' is used. v) When described in the singular, the plural can also be interpreted. vi) Even if numerical values, shapes, sizes comparisons, positional relations, etc. are not described as 'about' or 'substantial', they are interpreted to include a normal error range. vii) The terms 'after', 'before', 'following', 'and', 'here', and 'following' are not used to limit the temporal position. viii) The terms 'first', 'second', etc. are merely used selectively, interchangeably or repeatedly, for convenience of distinction and are not to be interpreted in a limiting sense. ix) When the positional relationship between two parts is described as 'upper', 'upper', '~ lower', 'next to', etc., at least one part between two parts is used unless 'baro' is used. Other parts may be interposed. x) When parts are connected by 'or', they are interpreted to include not only parts but also combinations, but only when parts are connected by 'or'.

1 is a schematic plan view for explaining an inline induction heating apparatus and an inline induction heating method using the same according to an embodiment of the present invention. FIG. 2 is a schematic side view for explaining the inline induction heating apparatus shown in FIG. 1.

1 and 2, the inline induction heating apparatus includes a width position measuring device 10 and an induction heating unit 20. The width direction position measuring device 10 measures the width direction position of the plate to be heated A moving along a predetermined direction. The width position detector 10 may be, but is not limited to, a center position control (CPC), an edge position control (EPC), or a laser sensor. In this case, the heating target plate A may include magnesium.

Induction heating unit 20 serves to heat the heating target plate (A) passing in between the induction heating coil (2) located up and down. In this case, the induction heating unit 20 may be moved to maintain a constant widthwise horizontal position with respect to the plate to be heated A by the widthwise position measured by the widthwise position measuring device 10.

The induction heating unit 20 includes an induction heating coil 2 provided to be rotatable in the upper and lower portions of the plate to be heated A. FIG. Induction heating coil 2 may be a plurality of coils have a rectangular shape as a whole, but is not limited thereto.

Since the induction heating coil 2 is rotatable horizontally at an angle in a plane parallel to the plate to be heated A, non-uniform heating according to the shape of the induction heating coil 2 when it is rotated at an appropriate angle It is possible to minimize and to cope with various rolling conditions such as heating temperature increase and decrease and width change of the heating target plate (A).

The induction heating unit 20 has an upper and lower shielding plate 4 positioned between the upper and lower induction heating coils 2 and the edges of the heating target plate A to shield heat applied from the induction heating coils 2 to the edges. It may further include.

The shield plate 4 is present between the induction heating coil 2 and the edge of the plate to be heated A and is heated instead of the edge of the plate A to be heated, so that the shield partially shields excessive heat from the edge. Suppresses crack dissolution, overheating and ignition of rolling oil. Unlike the heating target plate A moving here, the shield plate 4 is continuously heated to prevent damage by lowering the temperature through a cooling method such as water cooling. And the shielding plate 4 is comprised so that it may move horizontally in the width direction of the board | plate material A. FIG.

In the inverse heating method of the transverse method, the edge portion of the plate is severely heated, so a shielding plate 4 is required to alleviate this. On the contrary, when the shielding is excessive, the temperature of the edge is lowered, causing severe edge cracks. Since rolling becomes impossible, the position of the shielding plate 4 needs to be adjusted very finely for the width direction uniform heating. Therefore, when the induction heating coil 2 rotates horizontally and the shield plate 4 can move horizontally in the width direction, it is possible to precisely cope with various rolling conditions such as increasing and decreasing the heating temperature and changing the width of the heating target plate A. .

The induction heating coil 2 and the shield plate 4 are provided to enable vertical movement. That is, the induction heating coil 2 and the shielding plate 4 can move up and down in the direction perpendicular to the surface of the plate | plate material A to be heated.

Therefore, when the plate to be heated (A) is plated or when plate breakage occurs, the damage of the equipment is minimized by increasing the gap between the plate to be heated (A), the induction heating coil (2) and the shield plate (4) as much as possible, and the plate to be heated. When heating (A), the induction heating coil 2 and the shielding plate 4 are brought close to the heating target plate A, so that maximum thermal efficiency can be obtained.

The induction heating unit 20 may further comprise a frame 6 defining an exterior. The frame 6 may be a reference for movement of the induction heating coil 2 and the shield plate 4 and may be formed in a lattice shape, but is not limited thereto.

The induction heating unit 20 measures the temperature before the heating target plate A passes through the induction heating coil 2 and the temperature after the heating target plate A crosses the induction heating coil 2. It may further include an exit thermometer (8b) for measuring the.

The amount of induction current required to raise from the temperature detected by the entry thermometer 8a to the target temperature is calculated and supplied from the volume and heating efficiency of the plate A to be heated per hour passing through the inline induction heating apparatus, and this is output to the exit thermometer 8b. By some feedback control to the temperature detected by the to determine the in-line induction heating current for the heating target plate (A) to correspond to the high speed warm rolling.

3 is a schematic diagram illustrating vertical movement of an induction heating coil and a shield plate included in an inline induction heating apparatus.

Referring to FIG. 3, the induction heating coil 2 and the shield plate 4 are provided to enable vertical movement. That is, the induction heating coil 2 and the shielding plate 4 can move up and down in the direction perpendicular to the surface of the plate | plate material A to be heated.

Therefore, when the plate to be heated (A) is plated or when plate breakage occurs, the damage of the equipment is minimized by increasing the gap between the plate to be heated (A), the induction heating coil (2) and the shield plate (4) as much as possible, and the plate to be heated. When heating (A), the induction heating coil 2 and the shielding plate 4 are brought close to the heating target plate A, so that maximum thermal efficiency can be obtained.

4 is a schematic diagram illustrating the rotation of an induction heating coil included in an inline induction heating apparatus.

Referring to FIG. 4, the induction heating coil 2 is provided to be able to rotate at an angle horizontally in a plane parallel to the plate to be heated A. FIG. Therefore, when the induction heating coil 2 is rotated at an appropriate angle, it is possible to minimize non-uniform heating according to the shape of the induction heating coil 2 and to cope with various rolling conditions, such as a change in the width of the plate A to be heated. .

FIG. 5 is a schematic diagram illustrating horizontal movement of a shield plate included in an inline induction heating apparatus. FIG.

Referring to FIG. 5, the shielding plate 4 is configured to be horizontally movable in the plate width direction perpendicular to the direction in which the heating target plate A travels. In the inverse heating method of the inverse heating method, the edge of the plate is heated so much that a shielding plate is needed to alleviate this. On the contrary, if the shielding is excessive, the temperature of the edge is lowered, causing severe edge cracks, which makes warm rolling impossible. For uniform heating the position of the shielding plate needs to be very finely adjusted. Therefore, the optimum widthwise uniform heating condition can be obtained by mixing with the rotation function of the induction heating coil 2 and can cope with various rolling conditions such as the width change of the heating target plate A. FIG.

6 and 7 are schematic views showing the movement of the induction heating unit when moved in the plate width direction perpendicular to the direction in which the plate to be heated proceeds.

Referring to FIG. 6, the heating target plate A may be moved a predetermined distance in the width direction for reasons related to winding of a sheet coil. Referring to FIG. 6, the movement of the heating target plate A is measured by the width direction position measuring device 10.

Referring to FIG. 7, the induction heating unit 20 moves the position so that the heating target plate A may be uniformly heated in the width direction based on the measurement result of the moved degree of the heating target plate A. Referring to FIG. . For example, the induction heating unit 20 can move so that the center of the frame 6 included in the induction heating unit 20 is in the center of the width direction of the plate to be heated A. FIG.

1 is a schematic plan view for explaining an inline induction heating apparatus and an inline induction heating method using the same according to an embodiment of the present invention.

FIG. 2 is a schematic side view for explaining the inline induction heating apparatus shown in FIG. 1.

3 is a schematic diagram illustrating vertical movement of an induction heating coil and a shield plate included in an inline induction heating apparatus.

4 is a schematic diagram illustrating the rotation of an induction heating coil included in an inline induction heating apparatus.

FIG. 5 is a schematic diagram illustrating horizontal movement of a shield plate included in an inline induction heating apparatus. FIG.

FIG. 6 is a schematic view illustrating movement in a plate width direction perpendicular to a direction in which a plate to be heated moves, and FIG. 7 illustrates a position of an induction heating unit after measuring the width movement of the plate in a width direction position measuring device. Is a schematic diagram showing movement along the plate.

Claims (20)

About the width direction position of the board | substrate to be heated measured with the width direction position measuring instrument An inline induction heating apparatus comprising an induction heating unit that is movable to maintain a constant position. The inline induction heating apparatus according to claim 1, wherein the induction heating unit includes an induction heating coil rotatably provided on upper and lower portions of the plate to be heated. The inline induction heating apparatus according to claim 2, wherein the induction heating unit further comprises a shielding plate positioned between the induction heating coil and the edge of the plate to be heated to shield heat applied from the induction heating coil to the edge. 4. The inline induction heating apparatus according to claim 3, wherein the shield plate is water cooled. The inline induction heating apparatus according to claim 3, wherein the shielding plate is movable horizontally in the width direction of the plate to be heated. The inline induction heating apparatus of claim 3, wherein the induction heating coil and the shielding plate are provided to move vertically. 4. The inline induction heating apparatus according to claim 3, further comprising a frame defining an exterior of said induction heating unit. The inline induction heating apparatus according to claim 7, wherein the frame is a reference for movement of the induction heating coil and the shield plate. The induction heating unit further comprises an entrance thermometer measuring a temperature before the heating target plate passes the induction heating coil and an exit thermometer measuring a temperature after the heating target plate passes the induction heating coil. Inline induction heating apparatus comprising a. The inline induction heating apparatus of claim 1, wherein the width position measuring device is a center position control (CPC), an edge position control (EPC), or a laser sensor. The inline induction heating apparatus according to claim 1, wherein the plate to be heated comprises magnesium. Providing an induction heating coil to upper and lower portions of the plate to be heated moving along the movement path; And And rotating the induction heating coil horizontally to heat the plate to be heated. The inline induction heating method of claim 12, wherein a shielding plate is provided between the edge portion of the plate to be heated and the induction heating coil to partially block heat provided from the induction heating coil to the edge portion of the plate to be heated. . The inline induction heating method according to claim 13, wherein the shield plate is water cooled. The inline induction heating method according to claim 13, wherein the shielding plate is horizontally movable in a plate width direction perpendicular to a direction in which the plate to be heated moves. The inline induction heating method of claim 13, wherein the induction heating coil and the shield plate are vertically movable in a direction perpendicular to a surface of the plate to be heated. The in-line induction heating method according to claim 12, wherein the current provided to the induction heating coil is adjusted by measuring the temperature of the heating target plate before and after heating by the induction heating coil. The method of claim 12, wherein when the heating target plate is moved in the width direction of the plate perpendicular to the movement path, the movement degree is measured using a width direction position measuring device to determine the position of the induction heating unit In-line induction heating method corresponding to the. 19. The method of claim 18, wherein the width position measurer is a center position control (CPC), edge position control (EPC) or laser sensor. The inline induction heating method according to claim 12, wherein the plate to be heated comprises magnesium.

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