JP2012114058A - Coil of electromagnetic induction heating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a coil wire that is housed in recess of a coil base and formed by a plurality of electrically isolated conductors that are coated with insulation films, from dropping out from the recess.SOLUTION: A claw 12 is provided to a coil base, the upper surface of the claw 12 is formed into a shape inclined downward to a recess part 6, as an inclined part, and the lower surface 15 of the claw 12 is configured as a substantially horizontal surface so that a coil wire 5 housed in the recess part 6 is prevented from dropping out from the recess part 6, thereby fixing the coil wire 5 to the coil base stably without adding parts and members and without adding a processing step for fixing the coil wire 5.

Description

  The present invention relates to a coil that is heated by forming a substantially disk-shaped heating coil and applying electromagnetic induction heating.

  Conventionally, the coil of this type of electromagnetic induction heating apparatus has a configuration in which an electrically insulated conductor is housed in a disk-shaped coil base with a groove (see, for example, Patent Document 1). In addition, there is a configuration in which an electrically insulated conductor is solidified with a varnish or the like and bonded to a coil base (for example, see Patent Document 2).

  The coil of the conventional electromagnetic induction heating apparatus described in Patent Document 1 has a groove formed in a disk-shaped coil base, and a coil wire is processed into a flat shape so as to be accommodated in the groove, and the groove is mainly configured.

International Publication No. 2005/043960 JP 2002-043045 A

  However, in the conventional configuration, in Patent Document 1, the conductor may fall out of the groove due to vibration or inclination during assembly or transportation after the conductor is stored in the groove. Since the coil base is located under the top plate, it cannot be confirmed. Using the coil in a state where the coil has fallen out of the groove has a problem that it is difficult to ensure electrical insulation performance and maintain heating efficiency.

  The present invention solves the above-mentioned conventional problems, and an electromagnetic induction in which a coil wire formed of a plurality of electrically insulated conductors covered with an insulating film housed in a recess of a coil base does not fall out of the recess. It aims at providing the coil of a heating device.

  In order to solve the above-described conventional problems, the coil of the electromagnetic induction heating device according to the present invention includes a substantially disk-shaped coil base, a recess provided in a groove shape above or below the coil base, and an electric power embedded in the recess. A coil wire formed of a plurality of electrically insulated conductors, a claw provided near the entrance of the recess, and a ferrite forming a magnetic path, wherein the width of the coil wire is shorter than the width of the recess. The claw is smaller than the width of the recess, and the coil wire is stored in the recess through a narrowed portion that is a gap between the claw and the recess and is removed from the recess by the claw. This is a configuration that prevents withdrawal.

  Thus, when a coil wire formed of a plurality of electrically insulated conductors coated with an insulating film is stored in the recess, the plurality of conductors sequentially pass through the gap between the wall of the recess and the claw. If the coil wire is about to be detached from the recess by the claw, the apparent diameter of the wire cannot pass between the wall of the claw and the recess. Can be transported.

The coil of the electromagnetic induction heating device of the present invention includes a substantially disk-shaped coil base, a recess provided in a groove shape above or below the coil base, and a plurality of electrically insulated conductors embedded in the recess. A coil wire formed near the recess entrance, a ferrite that forms a magnetic path, a flat portion is provided between the ferrite and the coil wire, and the ferrite and the coil wire The width of the coil wire is shorter than the width of the recess and is more than half the width of the recess, the claw is smaller than the width of the recess, and the coil wire is formed between the claw and the recess. It is configured such that it passes through the narrowed portion that is a gap and is accommodated in the recess and is prevented from being detached from the recess by the claw, and the claw is positioned other than on the ferrite.

  As a result, it is possible to prevent the coil wire from leaving the recess while ensuring insulation between the ferrite and the coil wire, and at the same time maintain the insulation between the ferrite and the coil wire.

  The electric insulation performance can be maintained and the heating efficiency can be maintained without the coil wire of the coil of the electromagnetic induction heating device of the present invention being detached from the recess during assembly or transportation.

The fragmentary sectional view of the coil of the electromagnetic induction heating apparatus in Embodiment 1 of this invention The perspective view of the coil of the electromagnetic induction heating apparatus in Embodiment 1 of this invention The top view of the coil of the electromagnetic induction heating apparatus in Embodiment 1 of this invention The fragmentary perspective view of the coil of the electromagnetic induction heating apparatus in Embodiment 1 of this invention The perspective view of the electromagnetic induction heating apparatus in Embodiment 1 of this invention

  According to a first aspect of the present invention, there is provided a substantially disk-shaped coil base, a concave portion provided in a groove shape above or below the coil base, and a coil wire formed of a plurality of electrically insulated conductors embedded in the concave portion. A claw provided near the entrance of the recess, and a ferrite that forms a magnetic path, the width of the coil wire being shorter than the width of the recess and not less than half the width of the recess, The coil wire is smaller than the width, and the coil wire passes through the narrowed portion that is a gap between the claw and the concave portion and is stored in the concave portion, and is prevented from being detached from the concave portion by the claw. Even if an attempt is made to detach, the claw extending in the recess will prevent the detachment from the recess, and the detachment of the coil wire from the recess will be prevented without adding a member or further processing the recess. Can.

  In particular, the second invention is provided with an inclined surface that descends toward the concave portion at the top of the claw, and passes through the throttle portion between the inclined surface and the wall portion facing the claw while the cross section of the coil wire is deformed. The stepped surface of the coil wire is restored to be larger than the width of the restricting portion and is prevented from deforming into a shape passing through the restricting portion by contacting the lower surface of the claw after being accommodated in the recess. By doing so, the coil wire is guided to the concave portion along the inclined portion of the claw portion and can easily enter the concave portion, and the coil wire accommodated in the concave portion can be prevented from being detached from the concave portion.

In particular, the third invention relates to a coil formed of a substantially disk-shaped coil base, a recess provided in a groove shape above or below the coil base, and a plurality of electrically insulated conductors embedded in the recess. A wire, a claw provided in the vicinity of the recess entrance, and a ferrite that forms a magnetic path, and a plane portion is provided between the ferrite and the coil wire to electrically insulate the ferrite from the coil wire. The width of the coil wire is shorter than the width of the recess and is more than half the width of the recess, the claw is smaller than the width of the recess, and the coil wire is a gap between the claw and the recess. And the claw prevents the detachment from the recess by the claw, and the claw is located on a portion other than the ferrite, so that the ferrite and the coil wire are insulated at the flat portion. Since holding a coil wire in a plane and the recess together with the,
The insulation distance between the ferrite and the coil wire can be kept constant, and the electromagnetic characteristics can be kept constant.

  According to a fourth aspect of the present invention, in particular, the bottom of the recess of any one of the first to third aspects is opened downward at least in a position having a claw, and the coil wire can be viewed directly from below the coil base. In addition, the dimension that allows direct viewing of the coil wire is configured to dissipate the heat generated by the coil wire by configuring it to be at least twice the dimension in the direction along the recess of the claw. Since the temperature rise can be mitigated, the heat resistant temperature of the insulating film covering the coil wire can be set low.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a perspective view of a coil of an electromagnetic induction heating device according to a first embodiment of the present invention. FIG. 2 is a perspective view of the electromagnetic induction heating device according to the first embodiment. FIG. 3 shows a plan view of the coil of the electromagnetic induction heating device according to the first embodiment. FIG. 4 shows a partial perspective view of the coil of the electromagnetic induction heating device according to Embodiment 1 of the present invention. FIG. 5 shows a perspective view of the electromagnetic induction heating device according to Embodiment 1 of the present invention.

  In FIG. 5, the electromagnetic induction heating device main body 1 is a substantially rectangular parallelepiped and is stored in a standard hole (not shown) in which the size of the kitchen 2 is standardized, and the top plate 3 on which a heated object such as a pan is placed is placed in the kitchen. 2 Located at almost the same height as the upper surface, it is stored in the standard hole. The top plate 3 is a flat plate formed of heat-resistant glass using crystal glass or the like. As shown in FIG. 2, the coil base 4 is located below the top plate 3 in the electromagnetic induction heating device body 1. To do.

  The coil base 4 is made of a heat-resistant resin having a temperature of about 200 ° C. or higher, and has a substantially disk shape. The coil base 4 is positioned substantially parallel to the top plate 3 and substantially horizontally below the top plate 3. The coil base 4 is provided with a coil wire 5 through which a high frequency current of about several tens kHz to about 100 kHz is supplied. The coil wire 5 is formed of tens to thousands of copper wires, each of which is electrically insulated, and is electrically connected only at one end and the other end. That is, one end and the other end are electrically connected in parallel. The diameter of each copper wire is a thin wire of 0.05 mm to 0.5 mm, and an electric insulating film is formed by enamel and is electrically insulated from each other, but is electrically connected at one end and the other end. Therefore, one coil is electrically formed. The reason why the coil wire 5 is formed of a plurality of insulated copper wires is to secure a cross-sectional area through which a current flows against the skin effect caused by a high-frequency current.

  As shown in FIG. 1, the coil wire 5 is housed in a recess 6 that is a spiral groove formed in the coil base 4. The concave portion 6 is formed by left and right wall portions 7 having a groove shape. The bottom of the recess 6 is open in most parts. The dimensional relationship between the coil wire 5 and the recess 6 is that the apparent diameter of the coil wire 5 is more than half of the groove width of the recess 6, that is, the apparent diameter of the coil wire 5 is 50% of the groove width of the recess 6. That's it. Usually, it is set to a value close to the groove width of the recess 6 so as not to vibrate or move after being stored in the recess 6 as 90% or more.

As shown in FIG. 4, eight ferrites 8 are radially arranged from the center of the disk-shaped coil base 4 in a substantially horizontal direction on the lower surface of the coil base 4. The ferrite 8 is bonded to the lower surface of the coil base 4 with an adhesive. The shape of the ferrite 8 is a rectangular parallelepiped shape, and is arranged so that the longitudinal direction is the radial direction. The ferrite 8 has a function of converging the magnetic force lines generated from the coil wire 5 and efficiently transmitting the magnetic force lines to a heated object such as a metal pan placed on the top plate 3. The ferrite 8 is a metal oxide and has an electrical property close to that of a conductor. Therefore, it is arranged on the lower surface of the coil base 4 made of heat-resistant resin, and is arranged so as to face the coil wire 5 with the flat portion 9 provided above the ferrite 8 of the coil base 4 as an insulator.

  The coil wire 5 has a configuration in which a plurality of conductors are bundled, and is further twisted. Twist processing is performed in units of several to several tens, and the twist pitch is about several tens to 100 mm. In addition, the twisted wire (child twist) is further twisted (parent twist) to form a twisted wire, and the coil wire 5 is obtained. The effective resistance when a high-frequency current is applied to the coil wire 5 due to the skin effect by twisting can be reduced. Moreover, since the partial heat generation of the coil wire 5 can be dispersed by the proximity effect due to the high-frequency current, the local heat generation of the coil wire 5 can be suppressed and the entire coil wire 5 can be in a uniform temperature rise state. it can. By suppressing local heat generation, it is possible to suppress a local temperature rise exceeding the heat resistance limit of enamel which is an insulating film. In other words, by suppressing the local peak temperature rise exceeding the temperature limit of enamel, which is an electrical insulator, and making the temperature rise uniform, the allowable value of the temperature rise within the operating temperature of the coil wire 5 can be substantially increased. it can.

  As shown in FIGS. 1, 3, and 4, the coil wire 5 is accommodated in the recess 6, but most of the recess 6 is formed by the left and right wall portions 7 and has a cross-sectional shape that does not include the bottom portion 10. , A part of the bottom 10 is provided. The bottom portion 10 is provided with a flat portion 9 of the coil base 4 to which the ferrite 8 is bonded and a skeleton portion 11 provided in the coil base 4. That is, the plane portion 9 and the skeleton portion 11 form the bottom portion 10, and the heights of the upper surfaces of the plane portion 9 and the skeleton portion 11 are arranged at the same height to support the coil wire 5 from below. The skeleton part 11 is radially arranged on the substantially outer peripheral part of the coil base 4. This is because the flat portion 9 has the ferrite 8 arranged radially, and the flat portion 9 is also arranged radially, and the distance between the flat portion 9 and the adjacent flat portion 9 in the outer peripheral portion of the coil base 4. Therefore, the space for supporting the coil wire 5 from below is widened. Therefore, the skeleton portion 11 is provided to hold the coil wire 5.

  The coil wire 5 is positioned with respect to the ferrite 8 with the plane portion 9 interposed therebetween, and when it is positioned on the skeleton portion 11, the coil wire 5 is held by the skeleton portion 11. The coil wire 5 is sandwiched between the left and right wall portions 7 of the recess 6 in the cross section of the recess 6 other than the plane portion 9 and the skeleton portion 11.

  As shown in FIGS. 1 and 4, the claw 12 is extended from the wall portion 7. The claw 12 is provided in the vicinity of the entrance of the recess 6 and extends from one wall portion 7 of the entrance of the recess 6 toward the opposite wall portion 7. A plurality of claws 12 are provided substantially uniformly throughout the recess 6.

  The claw 12 extends from one wall portion 7 of the recess 6 in a range of about 20% to 70% of the width of the recess 6. That is, it extends from one wall portion 7 with a size smaller than the width of the recess 6. An upper surface of the claw 12 is provided with an inclined surface 13 inclined downward from the wall portion 7 of the recess 6 toward the center of the recess 6. When the coil wire 5 is housed in the recess 6, the inclined surface 13 guides the coil wire 5 to the recess 6, and the other end wall 7 facing the inclined surface 13 and the wall 7 provided with the inclined surface 13 in the recess 6. The coil wire 5 is gradually deformed so as to be inclined so as to pass through the narrowed portion 14 which is a narrow space between the claw 12 and the wall portion 7. Since the coil wire 5 has a configuration in which a plurality of copper wires are bundled together, the cross-sectional shape of the bundle is easily deformed. When the coil wire 5 is gradually deformed by the wall portion 7 facing the inclined portion and passes through the narrowed portion 14, the cross section of the twisted coil wire 5 is deformed to the width of the narrowed portion 14 and passes. To do.

The lower surface 15 provided at the lower part of the claw 12 opposite to the inclined surface 13 positioned at the upper part of the claw 12 is a substantially horizontal horizontal surface, and when the coil wire 5 accommodated in the concave part 6 tries to separate from the concave part 6, The lower surface 15 is substantially horizontal, but the coil wire 5 can be separated from the concave portion 6 when the width of the concave portion 6 suddenly becomes narrower than the lower surface 15. The configuration is not possible. That is, the claw 12 faces the inclined surface 13 and the inclined surface 13 in order to gradually deform the coil wire 5 when the coil wire 5 is housed in the recess 6 between the upper inclined surface 13 and the wall portion 7 facing the upper surface. The coil wire 5 is deformed by the wall portion 7 to be deformed to the same size as the width of the narrowed portion 14, and is passed through the narrowed portion 14 and accommodated in the concave portion 6.

  On the other hand, since the lower surface 15 has a horizontal shape, when the coil wire 5 accommodated in the recess 6 is to be detached from the throttle portion 14, the narrow space of the throttle portion 14 suddenly decreases from the width of the recess 6 due to the substantially horizontal lower surface 15. Since the coil wire 5 cannot be deformed and suddenly hits the lower surface 15 of the horizontal claw 12, the coil wire 5 is held by the claw 12 and received in the recess 6. Will remain. Thus, the coil wire 5 can be prevented from being detached from the recess 6 by the inclined surface 13 at the top of the claw 12, the wall 7 facing the claw 12, and the substantially horizontal lower surface 15.

  The dimension of the claw 12 in the direction of the coil wire 5 is about 4 to 10 mm. If the dimension is shorter than 4 mm, stress concentrates on the coil wire 5 when the coil wire 5 passes through the constricted portion 14, and if it exceeds 10 mm, the coil wire 5 is covered with the claws 12, which affects the cooling of the coil wire 5. Will be given. The bottom 10 is not provided below the nail 12. The bottom 10 is not provided below the nail in the range of the dimension along the coil wire 5 of the recess 6 and more than twice the dimension of the nail 12. Actually, the bottom 10 is provided at a distance of 10 mm or more from the nail 12.

  A fillet is provided at the edge of each part of the nail 12. This is because the coil wire 5 is deformed when passing through the narrowed portion 14 and at the same time there is a risk that the claws 12 may damage the enamel on the surface of the copper wire, so that fillets are formed on the claws 12 as much as possible.

  The dimensional relationship between the narrowed portion 14 and the coil wire 5 is that the apparent diameter of the coil wire 5 is larger than the size of the narrowed portion 14. Further, the groove width of the recess 6 is larger than the apparent diameter of the coil wire 5. The size of the narrowed portion 14 is set to 50 to 90% with respect to the apparent diameter of the coil wire 5. If the narrowed portion 14 is small, the enamel of the coil wire 5 may be peeled off or the copper wire may be disconnected when the coil wire 5 passes, so care must be taken in setting. In addition, the apparent diameter of the coil wire 5 with respect to the restricting portion 14 is accurately set to a ratio to the apparent diameter of the coil wire 5 that has once passed through the restricting portion 14 and is accommodated in the recess 6. However, since the apparent diameter of the coil wire 5 hardly changes even if it passes through the restricting portion 14, the apparent diameter of the coil wire 5 can be used.

  In the entire coil wire 5, the left and right sides are held by the wall portion 7, the upper side is pressed by the lower surfaces 15 of the plurality of claws 12, and the lower side is the flat portion 9 and the skeleton portion 11 of the coil base 4 positioned on the ferrite 8. The coil wire 5 is housed and held in the recess 6. Since the nail | claw 12 becomes a structure which covers the coil wire 5 slightly, the cooling effect with respect to the heat_generation | fever of the coil wire 5 becomes weak. In order to maintain cooling of the coil wire 5, the bottom portion 10 is not formed in the vicinity of the claw 12. Specifically, the coil wire 5 is held by the wall portion 7 and the lower surface 15 without cutting out the bottom portion 10 or forming the bottom portion 10 itself below the claw 12. As described above, in the coil wire 5 as a whole, the coil wire is appropriately held from below by the plane portion 9 and the skeleton portion 11 at a plurality of circumferential positions, so that the bottom portion 10 does not exist below the claws 12. This does not interfere with the housing and holding of the coil wire 5 in the recess 6.

As shown in FIGS. 2 and 3, the arrangement of one end and the terminal end of the coil wire 5 is such that one end of the coil wire 5 is coiled in a through-hole portion 16 extending vertically through the coil base 4 provided in the approximate center of the coil base 4. The base 4 is passed from above to below. The end of the coil wire 5 is hooked on a hook portion 17 provided on the outer periphery of the coil base 4, and the setting of the coil wire 5 is completed. The hook portion 17 is disposed outside the concave portion 6 on the outer periphery of the coil base 4, and the coil wire 5 drawn from the concave portion 6 is hooked on the hook portion 17 on a substantially U-shape or wound around the hook portion 17. The detachment of the coil wire 5 from the recess 6 is prevented. Although the claw 12 is disposed in the vicinity of the hook portion 17, the hook portion 17 is provided at the end of the coil wire 5 because there is a high possibility that excessive stress is applied during assembly processing and transportation.

  An apparatus for accommodating the coil wire 5 in the recess 6 is a design category, and a specific apparatus is omitted, but a portion for accommodating the coil wire 5 in the recess 6 will be described. As shown in FIG. 1, the wheel 18 is disposed at a certain height from the coil base 4. The lower portion of the wheel 18 is positioned at the height of the inclined surface 13 of the claw 12 of the recess 6.

  About the coil of the electromagnetic induction heating apparatus comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  First, one end of the coil wire 5 is passed through the through-hole portion 16 from above the coil base 4 downward. A part of the coil wire 5 is accommodated in the starting position of the recess 6 near the through hole 16. After a part of the coil wire 5 is accommodated in the recess 6 in the vicinity of the through-hole portion 16, the lower portion of the wheel 18 pushes the coil wire 5 from above, or the coil base 4 rises and the lower portion of the wheel 18 is connected to the claw 12. It approaches to the inclined surface 13 height. If the coil wire 5 is supplied to the recess 6 at a speed close to the rotation speed while the coil base 4 rotates or the wheel 18 rotates, the coil wire 5 is pushed into the recess 6 due to the positional relationship between the wheel 18 and the recess 6.

  The coil wire 5 is pressed against the inclined surface 13 of the claw 12 and formed of a plurality of copper wires, and the twisted coil wire 5 is deformed by the inclined surface 13 so that the inclined portion and the claw 12 face each other. It passes through the gap of the throttle portion 14 between the wall portion 7 and the recess portion 6. At this time, when the coil wire 5 comes to the position of the claw 12, it is pushed by the wheel 18 and is pushed against the inclined portion. Since the inclined portion descends toward the recess 6, the twisted coil wire 5 is pushed into the narrowed portion 14 along the inclined portion while deforming its cross section. In the restricting portion 14, the cross section of the coil wire 5 is deformed into a vertically flat shape so as to be sandwiched between the claw 12 and the wall portion 7, and the copper wire constituting the coil wire 5 is successively drawn by the wheel 18. While being pushed into the portion 14, it passes through the throttle portion 14 and is stored in the recess 6. The coil wire 5 is pushed in from above the recess 6 and is sandwiched between the left and right wall portions 7 of the recess 6 and accommodated in the recess 6.

  When the coil wire 5 is housed in the recess 6, the cross-sectional shape is restored by the elasticity of a plurality of copper wires in which the flat cross section is twisted at the moment of passing through the narrowed portion 14, and the twist is almost the original circular shape. A cross section of the line. The operation of storing the coil wire 5 in the recess 6 is continued, the wheel 18 is moved along the recess 6 from the inner periphery to the outer periphery of the coil base 4, and the storing of the coil wire 5 in the recess 6 is completed.

  In the part where the claw 12 is provided, the coil wire 5 accommodated in the recess 6 has a substantially circular cross-section restored from the flat deformation that has passed through the throttle 14, so it is about to come out of the recess 6. Since the lower surface 15 of the claw 12 is substantially horizontal, the lower surface 15 is obstructed, so that the copper wire of the coil wire 5 passes through the throttle portion 14 from the inclined surface 13 in order. Lines cannot pass sequentially. Even if trying to pass at once, the size of the drawn portion 14 is smaller than the apparent diameter of the coil wire 5, so that the twisted coil wire 5 is not deformed and the copper wire is twisted so The coil wire 5 cannot pass through the throttle portion 14 because it cannot pass through the portion 14.

  Since the plurality of claws 12 are provided on the coil base 4, the entire coil wire 5 does not come out of the recess 6. Even if the coil base 4 is subjected to vibration or impact during processing or transportation as a product, the coil wire 5 does not come off from the recess 6.

  As described above, in the present embodiment, the claw 12 is extended in the recess 6, the upper surface of the claw 12 is inclined toward the recess 6, and the lower surface 15 of the claw 12 is formed horizontally, whereby the coil wire 5 is recessed. It is possible to prevent separation from 6.

  Moreover, in this Embodiment, although the nail | claw 12 fulfill | performs the function by providing in the one wall part 7 of the recessed part 6, you may extend from both the wall parts 7. FIG.

  By forming the claw 12 in a cut-off configuration, the claw 12 can be formed with the same mold when the coil base 4 is formed of a heat-resistant resin, so there is no economical burden in processing and the coil can be prevented from being detached at a low cost. Can be achieved.

  Further, the claw 12 of the present embodiment has a configuration in which the width of the wall of the concave portion 6 is partially narrowed and the lower portion of the narrowed throttle portion 14 is made wider than the throttle portion 14. By causing the lower surface 15 of 12 to prevent the coil wire 5 from coming off, the coil wire 5 can be prevented from coming off from the recess 6.

  As described above, in the coil of the electromagnetic induction heating device according to the present invention, the coil wire 5 is recessed 6 against vibration and impact without changing the coil base 4 and without using different parts or different materials. Therefore, it is possible to easily secure the electric insulation performance and maintain the heating performance, so that the process for solidifying the coil wire 5 and the adhesive for bonding the coil wire 5 are not required. Since the copper wire forming the coil wire 5 does not need self-bonding performance and may have a structure of only an insulating film, a heating coil can be formed with an inexpensive material and a simple construction method. Applicable to applications such as coils.

4 Coil Base 5 Coil Wire 6 Recess 7 Wall 8 Ferrite 9 Plane 12 Claw 13 Inclined Surface 14 Diaphragm 15 Bottom

Claims (4)

A substantially disk-shaped coil base, a recess provided in a groove shape above or below the coil base, a coil wire formed of a plurality of electrically insulated conductors embedded in the recess, and near the entrance of the recess The coil wire has a width that is shorter than the width of the concave portion and more than half the width of the concave portion, and the claw is smaller than the width of the concave portion, The coil of the electromagnetic induction heating device is configured such that the wire passes through the constricted portion which is a gap between the claw and the recess and is housed in the recess and is prevented from being separated from the recess by the claw. An inclined surface that descends toward the concave portion is provided at the upper portion of the claw, and after passing through the constricted portion between the inclined surface and the wall portion facing the claw while being deformed in the cross section of the coil wire, is stored in the concave portion 2. The electromagnetic wave according to claim 1, wherein the stepped surface of the coil wire is restored to be larger than the width of the throttle portion and is prevented from being deformed into a shape passing through the throttle portion by contacting the lower surface of the claw. Coil for induction heating device. A substantially disk-shaped coil base, a recess provided in a groove shape above or below the coil base, a coil wire formed of a plurality of electrically insulated conductors embedded in the recess, and near the entrance of the recess Provided with a claw and a ferrite forming a magnetic path, a plane portion is provided between the ferrite and the coil wire to electrically insulate the ferrite and the coil wire, and the width of the coil wire is The width is shorter than the width of the concave portion and more than half the width of the concave portion, the claw is smaller than the width of the concave portion, and the coil wire is accommodated in the concave portion through a narrowed portion that is a gap between the claw and the concave portion. And the coil of the electromagnetic induction heating apparatus which made it the structure which prevented the detachment | leave from the said recessed part with the said nail | claw, and the said nail | claw was located in other than the said ferrite. The bottom of the recess is at least at the position where the claw is provided, the bottom is opened downward, the coil wire can be viewed directly from below the coil base, and the dimension that the coil wire can be directly viewed is the direction along the recess of the claw The coil of the electromagnetic induction heating device according to any one of claims 1 to 3, wherein the coil is configured to be at least twice as large as the size of the electromagnetic induction heating device.