Induction heating device and method

Abstract

The present invention relates to an induction heating device for induction-heating an object having a flat plate shape extending in a first direction while the object is moving in a second direction. According to the present invention, the induction heating device comprises: a plurality of loop-shaped coils spaced apart from a heating surface of an object and having a long axis in a first direction; and a plurality of cores arranged side by side in the first direction in the inner space of respective coils. The plurality of coils are arranged in the second direction and disposed to correspond to the width direction of the object. According to the present invention, uniform induction heating can be realized with regard to the entire area of the moving object by arranging the plurality of coils and the cores.

Description

Induction heating device and method

[0001] The present invention relates to an induction heating device and method, and more specifically, to an induction heating device and method capable of selectively activating a core.

[0002] Induction heating technology is a technology that forms an induced current inside a conductor by a magnetic field generated by applying an alternating current to a conductor, and heats an object using the resistive heating of that current.

[0003] Since this technology utilizes a non-contact method where the heating coil does not come into direct contact with the object, it offers the advantages of reduced contamination and wear, as well as the ability to heat the object to a desired temperature in a short period of time. For these reasons, it is widely used in various industrial fields, including metalworking, heat treatment, surface hardening, welding, and semiconductor processes.

[0004] In particular, induction heating technology is increasingly being applied in heating processes for flat-plate shapes. In manufacturing processes for thin metal substrates such as electrode current collectors, a step of drying the solvent of the slurry applied to the surface of the substrate is essential.

[0005] In this case, using induction heating allows the metal substrate itself to become a heat source, enabling rapid removal of internal moisture from the slurry and thus increasing drying efficiency. Additionally, applying induction heating in the heat treatment process of thin film materials can achieve uniform temperature conditions within a short period of time, making it a noteworthy means of enhancing process stability.

[0006] Conventional induction heating devices generally have a configuration in which a coil wound at a position spaced apart from the object is placed, and the object is heated by an alternating magnetic field generated by applying an alternating current to the coil. The coil may be placed only on the upper part of the object, or placed oppositely on the upper and lower parts, and, if necessary, multiple coils are connected in parallel or series to apply current.

[0007] While such general devices had the advantage of a simple structure and applicability to various metal materials, they had limitations in forming a uniform magnetic field across the entire width direction of the flat plate.

[0008] Due to these limitations, when heating a flat plate, a phenomenon occurred in which the magnetic field concentrated in specific areas, particularly at the edges of the electrode current collector, depending on the shape or placement of the coil. As a result, a problem arose where excessive localized heating occurred at the edges of the object, while the central region did not heat up sufficiently.

[0009] The present invention aims to provide an induction heating device capable of achieving uniform heating across the entire area by preventing local overheating that occurs during the process of induction heating a moving flat plate-shaped heating element.

[0010] In addition, the present invention aims to provide an induction heating device capable of stably performing uniform heating by varying the arrangement of the core to accommodate changes in the width of the heating element.

[0011] The problems to be solved by the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art to which the present invention belongs from the description below.

[0012] An induction heating device for heating an object moving in a second direction perpendicular to the first direction, having a flat plate shape extended in a first direction, comprises a loop-shaped coil spaced apart from the heating surface of the object and having a long axis in the first direction, and a plurality of cores arranged in the internal space of the coil and arranged in the first direction, wherein the coil may be provided in a plurality and arranged in the second direction.

[0013] Current can be applied in the same direction to the windings of adjacent coils among the plurality of coils above.

[0014] The above plurality of cores can be formed of ferrite material.

[0015] The plurality of cores are formed with the same size and can be arranged at equal intervals along the first direction.

[0016] The device may further include a core driving module that moves the plurality of cores linearly in a third direction perpendicular to the first direction and the second direction to separate them from the coil.

[0017] Each of the above plurality of cores may be in the form of a column extending in the above third direction.

[0018] The core driving module may include a variable part that moves some of the multiple cores and a fixed part that fixes the remaining cores excluding some of the multiple cores.

[0019] The core driving module above can be selectively driven so that a core located outside the length region of the first direction of the object among the plurality of cores is spaced apart from the coil.

[0020] The inner diameter of the above coil may be 40 mm or less.

[0021] The spacing between adjacent coils among the above plurality of coils may be 20 mm or less.

[0022] An induction heating method for heating an object moving in a second direction perpendicular to the first direction in a flat plate shape extended in a first direction may include the steps of: providing a plurality of coils arranged in the second direction having a loop shape having a long axis in the first direction and spaced apart from the heating surface of the object; arranging a plurality of cores in the first direction within the internal space of each of the plurality of coils; and applying power to the plurality of coils to heat the object.

[0023] The method may further include the step of applying a current in the same direction to the winding of an adjacent coil among the plurality of coils.

[0024] The method may further include the step of moving the plurality of cores in a straight line in a third direction perpendicular to the first direction and the second direction to separate them from the induction heating coil.

[0025] The above separation step may include a step of selectively separating a core located outside the length region of the first direction of the object from the coil.

[0026] According to one embodiment of the present invention, uniform heating can be achieved over the entire area of ​​the heating body.

[0027] In addition, by moving the core in the vertical direction to control activation or deactivation, stable and uniform heating can be performed even with changes in the width of the heating element.

[0028] In addition, by limiting the inner diameter of the coil and the spacing between coils, the diffusion of the magnetic field can be suppressed and heating efficiency can be improved.

[0029] Further scopes of the applicability of the present invention will become apparent from the following detailed description. However, since various changes and modifications within the spirit and scope of the present invention are clearly understood by those skilled in the art, specific embodiments, such as the detailed description and preferred embodiments of the present invention, should be understood as being given merely as examples.

[0030] FIG. 1 is an induction heating device according to one embodiment of the present invention.

[0031] FIG. 2 is a plan view illustrating a plurality of coils and a core according to one embodiment of the present invention.

[0032] FIG. 3 is a side view illustrating a core driving module according to one embodiment of the present invention.

[0033] FIG. 4 is a diagram illustrating the control of a core driving module according to an embodiment of the present invention.

[0034] Hereinafter, embodiments disclosed in this specification will be described in detail with reference to the attached drawings. Identical or similar components regardless of drawing symbols are given the same reference number, and redundant descriptions thereof will be omitted.

[0035] The suffixes "module" and "part" for components used in the following description are assigned or used interchangeably solely for the ease of drafting the specification, and do not inherently possess distinct meanings or roles. Furthermore, in describing the embodiments disclosed in this specification, detailed descriptions of related prior art are omitted if it is determined that such detailed descriptions could obscure the essence of the embodiments disclosed in this specification.

[0036] In addition, the attached drawings are intended only to facilitate understanding of the embodiments disclosed in this specification, and the technical concept disclosed in this specification is not limited by the attached drawings; it should be understood that all modifications, equivalents, and substitutions included within the concept and technical scope of the present invention are included.

[0037] Terms including ordinal numbers, such as first, second, etc., may be used to describe various components, but said components are not limited by said terms. These terms are used solely for the purpose of distinguishing one component from another.

[0038] When it is stated that one component is "connected" or "connected" to another component, it should be understood that while it may be directly connected or connected to that other component, there may also be other components in between. On the other hand, when it is stated that one component is "directly connected" or "directly connected" to another component, it should be understood that there are no other components in between.

[0039] A singular expression includes a plural expression unless the context clearly indicates otherwise.

[0040] In this application, terms such as “comprising” or “having” are intended to specify the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0041] FIG. 1 is a schematic perspective view illustrating an induction heating device according to one embodiment of the present invention.

[0042] The induction heating device (1) is configured to heat a flat plate-shaped object (S) extended in a first direction (x) while moving it in a second direction (y). The object (S) may be a metal flat plate substrate, such as an electrode current collector, for example, and may be continuously transported in a second direction (y) to dry the solvent of the slurry applied to the surface.

[0043] Hereinafter, for convenience of explanation, the object (S) may be described interchangeably with a flat plate. The flat plate may be in the shape of a rectangular metal plate having a longer side in the first direction.

[0044] In order to apply the induction heating device according to one embodiment of the present invention, another device may be used to enable the metal plate substrate to move in a second direction. In this case, the second direction may be a direction perpendicular to the first direction and parallel to the shorter side of the metal plate. That is, the rectangular plate substrate may move in the width direction.

[0045] An induction heating device according to one embodiment of the present invention may include a plurality of coils and a plurality of cores.

[0046] Multiple coils (100) may be arranged side by side along the second direction (y) at the top or bottom of the object (S), or simultaneously. The drawing illustrates an embodiment in which coils are arranged at the bottom.

[0047] In particular, unlike conventional general induction heating devices, the present invention does not necessarily require coils to be installed on both sides; instead, a uniform heating effect can be achieved on an object (S) even if a coil is placed on only one side. As a result, the freedom of installation method is increased, the structure is simplified, and the manufacturing and operation of the device can be made easier.

[0048] Each coil (100) has a loop shape with the first direction (x) as its major axis and can be positioned at a predetermined distance from the heating surface of the object (S). That is, it is located above or below the object and is arranged in parallel in the direction in which the object moves, and each may have a shape that extends in the same length direction as the object.

[0049] Multiple cores (200) can be arranged side by side along the first direction (x) inside each coil (100).

[0050] The core (200) is formed in the shape of a pillar made of ferrite material and can be accommodated inside the coil. The core concentrates the magnetic field of the coil to ensure that an induced current is smoothly generated in the object (S). Multiple cores (200) can be arranged at equal intervals and can be selectively activated or deactivated depending on changes in length or position of the object (S).

[0051] Also, referring to FIG. 1, the object (S) can be transported in a second direction (y) by a conveyor system. During transport, uniform heating is achieved over the entire area of ​​the object (S) by the upper and lower coils (100) and the core (200). The arrangement of the coils and the core can be designed so that local overheating does not occur at the edges of the object (S), and can be configured to enable stable heating even in the central area.

[0052] FIG. 2 illustrates the coil arrangement and core arrangement of an induction heating device according to one embodiment of the present invention in plan view.

[0053] As described above, the object (S) has a flat plate shape extending in the first direction (x) and can move in the second direction (y). The coils (100a, 100b) can be spaced apart from the heating surface of the object (S) at a predetermined distance. That is, the coils can be positioned spaced apart from the upper or lower part of the object.

[0054] The coil (100a, 100b) may be a loop shape having a major axis in the first direction (x). For example, it may be configured as a loop coil in a shape such as an ellipse or a rounded rectangle extending in the first direction.

[0055] To explain in more detail, the shape must be extended in the same direction as the object, and it is preferable that the width be narrower than the object. In this case, it is desirable that the major axis of the coil, that is, the size of the coil, be greater than or equal to the maximum length of the object so that the entire length of the object is contained within the range of the coil.

[0056] Multiple coils may be arranged and may be arranged side by side along the second direction (y). Here, as an example, an example in which four coils are arranged side by side is illustrated, and 100a and 100b may be symbols representing two adjacent coils.

[0057] To achieve the effect of heating the object uniformly so that the heating is not concentrated at the edges, it is effective to arrange at least two loop-shaped coils with a radius narrower than the width of the object side by side.

[0058] In the internal space of each coil (100), a plurality of cores (200) may be arranged at equal intervals along the first direction (x). At this time, for more effective uniform heating, the size and width of each core may be the same, and it is preferable that the spacing between each coil be equal.

[0059] The core (200) may be a columnar shape having an axis extending in the third direction (z). The core (200) serves as a member that concentrates the magnetic path inside the coil and may be arranged in equal numbers and at equal pitch for each coil. The cross-sectional shape of the core (200) may be formed as a circle, an ellipse, or a polygon, and may be changed depending on the device manufacturing and cooling structure.

[0060] The core (200) is a magnetic core made of ferrite material and can be applied to high-frequency induction heating. Since ferrite has the characteristics of effectively suppressing magnetic flux leakage and minimizing electromagnetic loss, it can be utilized to concentrate the magnetic field generated inside the coil (100). In addition, the ferrite core has high insulation and heat resistance, so it can be used stably even in a repetitive heating environment.

[0061] Meanwhile, during moving heating, especially in the case of discontinuous objects, the edge heating in the lateral direction moving from the object tends to be the highest. To mitigate this phenomenon, it is desirable to configure it as follows.

[0062] For example, the spacing (a) between adjacent coils can be defined based on the second direction (y). The spacing (a) can preferably be set to be between 1 mm and 20 mm. In particular, reducing the spacing between sub-coils can further concentrate the magnetic field, thereby further improving the heating characteristics of the center of the heating body. To maximize this magnetic field concentration effect, it is preferable to arrange two or more sub-coils. The spacing between each coil can be determined by considering magnetic field concentration and the uniformity of the object (S) in the width direction.

[0063] Additionally, the inner diameter (b) of each coil can be defined as the inner width of the loop based on the second direction (y). It may be preferable for the inner diameter (b) to be formed to be between 10 mm and 40 mm. As the inner diameter is reduced in this way, edge heating concentration can be reduced. The inner diameter (b) can be set by considering not only the size of the object but also the outer shape of the core (200), cooling margin, and winding thickness.

[0064] Meanwhile, the direction of the current flowing through the wires of adjacent coils among the plurality of coils (100a, 100b) can be formed to be the same. That is, the flow of current applied to each coil is configured to be in opposite directions between adjacent coils. For example, if current flows counterclockwise in one coil (100a), the power supply connection can be made so that current flows clockwise in the adjacent coil (100b).

[0065] In one embodiment, when four coils (100a to 100d) are arranged side by side along the y-axis, current is arranged to flow alternately in opposite directions (clockwise / counterclockwise) through the connection of the power supply. For example, current flows counterclockwise in 100a, clockwise in 100b, counterclockwise in 100c, and clockwise in 100d (see arrow in FIG. 2). This structure can maximize the magnetic field concentration effect between adjacent coils, thereby improving the heating performance and temperature uniformity of the center of a flat object.

[0066] FIG. 3 is a side view illustrating a core driving module according to one embodiment of the present invention.

[0067] In a core driving module according to one embodiment of the present invention, a plurality of cores (200a to 200g) are arranged side by side along a first direction (x), and these cores may be formed in a column shape extending in a third direction (z).

[0068] At this time, the entire core is not completely located inside the coil (100), and only a portion of the core overlaps with the coil. That is, the core (200) is magnetically coupled only in the portion where the coil is located out of its total length, and the remaining portion may exist exposed outside the coil (100).

[0069] Some cores may be spaced apart from the coil (100) by a certain distance (c), where the distance (c) corresponds to the thickness of the coil. In this structure, if the core is separated from the outer edge of the coil by a certain distance, the core may be deactivated without affecting the object. This distance (c) may be set, for example, to at least 5 mm or about 10 mm. The distance (c) can be used as a design parameter to control the degree of magnetic coupling between the coil and the core.

[0070] To this end, the core may be installed in a core drive module. The core (200) may have a fastening portion on its upper or lower surface and be guided linearly in a third direction (z). The guide structure may consist of a sliding bush and a guide rod, and may be fixed in position by a pressure spring or a fastening pin. The arrangement pitch of the core may be set considering the inner diameter (b) of the coil loop, the winding window width, and the magnetic flux path length. The arrangement pitch may be selected in correspondence with the first direction (x) temperature distribution target resolution of the object (S).

[0071] The core (200a, 200g) may be supported from below by a core support (201). The core support (201) may include a structure capable of stably fixing or selectively moving a plurality of cores. For example, the core support (201) may include a fixed portion (210) and a variable portion (220). The fixed portion (210) may fix some cores (200a) so that they are positioned inside the coil (100) to maintain them in a magnetic path at all times. To this end, the fixed portion (210) may include a fastening portion that is coupled to the bottom of an individual core, and the fastening portion may be connected to the core end via an insertion or fastening structure.

[0072] The variable part (220) can move the remaining core (200a) in a third direction (z) to separate it from the coil (100). The variable part (220) is a structure for controlling the selective activation or deactivation of the core, and can implement linear movement, for example, through a linear actuator (221), a cam structure, or a screw coupling structure. Through this, the core located outside the first direction (x) length of the object can be excluded from magnetic circuit formation and can be reactivated if necessary.

[0073] The fixed part (210) and the variable part (220) can be provided within an integrated frame, allowing for stable control of separated cores when switching drives. Accordingly, some cores always maintain magnetic coupling with the coil (100), while the remaining cores are separated and controlled as needed, thereby enabling uniform heating even with changes in the length or position of the object.

[0074] At this time, the control unit of the core driving module can select an effective core range corresponding to the first direction (x) length area of ​​the object (S). For example, a core (200) placed at a position beyond the end of the length of the object (S) can be moved in the third direction (z) to be separated from the coil. This selective separation can be performed in conjunction with the core driving module, and the selective separation can be applied according to changes in the length of the object (S) or edge conditions. A more detailed explanation regarding this is given with reference to the following drawings.

[0075] FIG. 4 is a diagram illustrating the control state of a core driving module according to an embodiment of the present invention. The coil (100) is formed in a loop shape and can be spaced apart from the heating surface of a flat object (S). In the internal space of the coil (100), a plurality of cores (200d, 200e, 200f, 200g) are arranged side by side along a first direction.

[0076] Each core (200d to 200g) has a columnar shape extending in the third direction (z) and is optionally movable. As illustrated in the drawing, some cores may be located within the first direction length range of the object (S), and some cores may be located outside the first direction length. Cores located outside may be separated from the coil (100) and excluded from the magnetic circuit under control.

[0077] In particular, to reduce heat concentration in the width direction (second direction), the core may be positioned at a certain distance (d) from the edge of the object (S). That is, the core may be activated to be effective only within the length range of the object.

[0078] At this time, the spacing (d) can be spaced apart from, for example, a minimum of 2 mm to a maximum of 30 mm. This is effective in preventing uneven heating of the core at the edge of the heating element and ensuring a uniform heat distribution throughout.

[0079] Additionally, in an area smaller than the minimum size of the heating body, the fixed part (210) fixes the core (200) to maintain a stable magnetic coupling at all times, and the variable part (220) varies the core (200) in the vertical direction (third direction, z) according to the change in the width direction of the heating body so that it can be switched to an active or inactive state as needed.

[0080] As such, the fixed part (210) maintains the core (200) in a fixed position, and the variable part (220) adjusts the position of the edge core (200) to enable flexible and consistent control over the entire heating area. For example, the fourth core (200d) may be the variable part, and the fifth to seventh cores (200e~g) may be the fixed part. More specifically, in another embodiment, when an object shorter than the length of the drawing needs to be heated, the fourth core (200d) may be moved and deactivated, and only the remaining cores may be activated.

[0081] Referring to FIG. 3, each core (200d to 200g) has a column shape extending in a third direction and has a structure that can be selectively moved. For example, some cores are coupled to a linear actuator and can move in a third direction (z) according to the driving signal of an electric motor. When a change in the length of the object (S) is detected, a sensor module sends a signal to automatically separate the unnecessary parts of the cores, and in the necessary sections, the cores are maintained in a position close to the coil (100) so that uniform magnetic coupling can be achieved.

[0082] Additionally, the movement of the core can also be manually controlled. The user can adjust the position of the core by rotating a hand knob or a cam structure attached to the variable part (220), and the position can be stably fixed through a fastening pin or a pressure spring. A coupling insert is provided at the end of the core, so that it can be easily connected to and disconnected from the core support (201).

[0083] Depending on the implementation, the core driving module can be implemented to move multiple cores at once or to selectively adjust only individual cores. For example, the fixed part (210) can fix the central core that always requires heating, and the variable part (220) can independently separate the edge cores according to the length or temperature distribution of the object (S).

[0084] Through such embodiments, it is possible to effectively respond to various sizes and shapes of objects and changes in temperature distribution, and simultaneously secure energy efficiency and heating uniformity.

[0085] It is obvious to those skilled in the art that the present invention may be embodied in other specific forms without departing from the spirit and essential features of the invention.

[0086] The foregoing detailed description should not be interpreted restrictively in all respects and should be considered exemplary. The scope of the invention shall be determined by a reasonable interpretation of the appended claims, and all modifications within the equivalent scope of the invention are included within the scope of the invention.

Claims

1. An induction heating device for heating an object that moves in a second direction perpendicular to the first direction, having a flat plate shape extended in a first direction, A loop-shaped coil spaced apart from the heating surface of the object and having a long axis in the first direction; and It includes a plurality of cores arranged in the first direction and disposed in the internal space of the above coil, An induction heating device characterized by having a plurality of coils arranged in the second direction.

2. In Paragraph 1, An induction heating device characterized by applying current in the same direction to the windings of adjacent coils among the plurality of coils.

3. In Paragraph 1, An induction heating device characterized in that the plurality of cores are formed of ferrite material.

4. In Paragraph 1, An induction heating device characterized in that the plurality of cores are formed of the same size and arranged at equal intervals along the first direction.

5. In Paragraph 1, An induction heating device characterized by further including a core driving module that moves the plurality of cores linearly in a third direction perpendicular to the first direction and the second direction to separate them from the coil.

6. In Paragraph 5, An induction heating device characterized in that each of the above plurality of cores is in the form of a column extending in the third direction.

7. In Paragraph 5, The above core driving module is A variable part that moves some of the above plurality of cores; and An induction heating device characterized by including a fixing part that fixes the remaining cores, excluding some of the aforementioned multiple cores.

8. In Paragraph 5, The above core driving module is An induction heating device characterized by selectively driving a core among the plurality of cores located outside the length region of the first direction of the object to be spaced apart from the coil.

9. In Paragraph 1, An induction heating device characterized by the inner diameter of the coil being 40 mm or less.

10. In Paragraph 1, An induction heating device characterized in that the spacing between adjacent coils among the plurality of coils is 20 mm or less.

11. An induction heating method for heating an object moving in a second direction perpendicular to the first direction in a flat plate shape extended in a first direction, A step of providing a plurality of coils arranged in the second direction, having a loop shape having a long axis in the first direction, spaced apart from the heating surface of the object; A step of arranging a plurality of cores in the first direction within the internal space of each of the plurality of coils; and An induction heating method comprising the step of heating an object by applying power to a plurality of coils.

12. In Paragraph 11, An induction heating method further comprising the step of applying a current in the same direction to the winding of an adjacent coil among the plurality of coils.

13. In Paragraph 11, An induction heating method further comprising the step of moving the plurality of cores in a straight line in a third direction perpendicular to the first direction and the second direction to separate them from the induction heating coil.

14. In Paragraph 13, The above separation step An induction heating method characterized by including the step of selectively separating a core located outside the length region of the first direction of the object from the coil.

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