JP2013134841A - Induction heating coil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture an induction heating coil with different coil characteristics using a coil base in common and to easily grasp at which part a coil conductor is arranged when changing coil characteristics.SOLUTION: The induction heating coil includes a coil conductor 14 which is wound in a radial direction a plurality of times and arranged between wall-shaped projection parts 13 provided with first intervals in the radial direction, and a coil base 12 which has the projection parts 13 formed on an upper surface, and holds the coil conductor 14. The projection parts 13 are formed on a plurality of concentric circles having their centers in the center of a heating coil 11 and differing in diameter, and have a cut at least at one place, and also include at least one group of projection parts 13 separated in the radial direction at second intervals 16 wider than the first intervals 15 and projection parts 13 at the first intervals 15 where the coil conductor 14 is not provided inside or outside the second intervals 16.

Description

  The present invention relates to an induction heating coil and an induction heating cooker including the induction heating coil.

  A conventional induction heating coil will be described with reference to FIGS. FIG. 6 is a cross-sectional view of a conventional induction heating cooker. A heated object 1 is induction heated by a high frequency magnetic field generated from a heating coil (induction heating coil) 2, and the heating coil 2 induction heats the heated object 1. The inverter circuit 3 supplies a high-frequency current to the heating coil 2 and is connected to the heating coil 2 although not particularly shown in the drawing. The plate 4 is the one on which the heated object 1 is placed, and the material thereof is ceramic. The coil base 6 mounts the heating coil 2, the magnetic body 7 is embedded in the coil base 6, and the material is ferrite. The magnetic body 7 is used for the purpose of efficiently supplying a high-frequency magnetic field generated from the heating coil 2 to the article 1 to be heated. The cooling device 8 cools the heating coil 2 by forced air cooling from the side surface of the heating coil 2 using an axial fan centrifugal fan or the like.

  FIG. 7 shows a view of the coil base 6 as viewed from above, and FIG. 8 shows a view of the coil base 6 as viewed from below. As shown in FIG. 8, the magnetic body 7 is composed of a plurality of rods, and is arranged radially on the lower surface of the coil base 6.

  Although the coil wire of the heating coil 2 is different depending on the induction heating cooker using the heating coil, it is configured by twisting about 30 to 100 strands having a diameter of about 0.2 mm to 0.5 mm. The material of the strand is copper, and its surface is covered with an insulator so that the strands are not electrically connected. Each strand is electrically connected at the start and end of the heating coil 2. The reason why such a thin wire is used as the coil wire of the heating coil 2 is that a high-frequency current having a frequency of about 20 to 30 kHz flowing through the heating coil 2 is concentrated on the surface of the coil wire due to the skin effect. This is because it is necessary to increase the surface area. The reason for twisting is that the distribution of current flowing in the coil wire is prevented from becoming non-uniform due to the proximity effect acting between the coil wires of the heating coil 2 due to the high-frequency magnetic field generated by the heating coil 2, and the heating coil This is because current is prevented from concentrating on the surface of the heating coil 2 (on the heated object 1 side) due to the proximity effect that acts between the heated object 2 and the heated object 1.

  When such a configuration in which strands are twisted together is not used, the loss of the heating coil 2 is increased, which is a problem in terms of temperature rise and heating efficiency. When the coil wire temperature exceeds approximately 180 ° C., it becomes difficult to insulate between the above-mentioned strands and between the coil wires, and in this case, it becomes impossible to function as a coil. Further, the number of turns of the coil shown in FIG. 7 is simply shown, and the actual number of turns is about 15 turns or more.

  However, the induction heating coil used in such a conventional induction heating apparatus has the following problems. That is, as described above, the heating configuration for performing induction heating such as a heating coil and a coil base or a magnetic material is complicated, and the manufacturing man-hours and parts costs are large, resulting in an increase in the cost of the product. In particular, the heating coil has a configuration in which a plurality of strands are twisted together, and its manufacturing man-hour is extremely large.

In order to reduce the manufacturing process and manufacturing cost of the heating coil from this background and to provide an inexpensive apparatus, a spiral protrusion is arranged on the coil base as in Patent Document 1, and a conductive wire is provided between the protrusions. Some have been proposed to form a spiral coil by fitting. As shown in FIG. 9, this is a heating coil construction method in which a conductive wire is pushed into a coil base between protrusions 103 by a roller that is relatively rotatable with respect to the coil base (for example, see Patent Document 1). .

  In the heating coil as shown in FIG. 7, since there is no means for fixing the coil wire in a spiral shape, a fusion layer formed of a resin or the like on the surface of the insulator covering the surface of the coil wire. Is provided and melted and fixed to fix the coil wire in a spirally wound state. Therefore, as in Patent Document 1, there are a step of forming a fusion layer on the surface of the coil wire by arranging a spiral projection on the coil base, and a step of fixing the coil wire in a spiral shape by melting the fusion layer. It becomes unnecessary, and the cost for the material of the fusion layer can be reduced.

JP-A-61-193394

  However, in the induction heating coil of the induction heating cooker having the conventional configuration as described above, when producing a heating coil with a limited outer diameter, the number of turns of the coil, that is, the number of turns, for obtaining sufficient performance is set. There was a problem that it could not be wound.

  If the thickness of the coil wire is too thin, the resistance of the coil wire increases and the loss increases, which causes a problem in terms of temperature rise and heating efficiency. For example, when 60 copper wires having a diameter of 0.3 mm with insulating coating are twisted together, the diameter becomes about 3.0 mm. The outer diameter of the coil is determined by the size of the induction heating cooker. Furthermore, when attaching a temperature detection sensor etc. to a heating coil, the area | region which can wind a coil copper wire will be restrict | limited.

  On the other hand, in the heating coil, a certain number of turns are required to heat the pan or to achieve high thermal efficiency, and as shown above, about 15 turns or more are required, and generally around 20 turns. If the number of turns is not sufficient, sufficient heating performance cannot be obtained, and sufficient input power to the pan that is the object to be heated cannot be secured. Therefore, in order to manufacture a high-performance heating coil that realizes multiple functions, it is important to secure a sufficient number of turns in a limited region. Under such circumstances, the heating coil configured as described above has a problem that if the coil wire is thick, a coil wire having a sufficient number of turns cannot be wound in a limited region. One method is to reduce the space between the spiral projections and wind a sufficient number of turns, but pushing the coil wire into a narrow space is difficult from the standpoint of construction. Become. Moreover, if the interval is narrowed, the thickness of the heating coil becomes thick, and it must be incorporated at a predetermined height of the induction heating cooker. Therefore, it is disadvantageous to increase the thickness of the heating coil. However, the flow path for flowing cooling air is more limited, which is a disadvantage. In addition, when the distance from the upper surface of the coil wire to the lower surface of the pan to be heated is the same, when the thickness of the coil wire of the heating coil increases, from the lower surface of the coil wire to the lower surface of the pan to be heated Since the magnetic field generated from the coil wire is difficult to reach the pan, the thicker coil wire of the heating coil leads to a decrease in the heating performance of the heating coil.

  In the conventional configuration as described above, the winding method for winding the coil wire of the coil base is one way of fitting between the spiral projections of the coil base, and changing the winding method changes the characteristics of the heating coil. I couldn't. Further, when changing the winding method to change the characteristics of the heating coil, it was also an issue to make it easy to understand which winding method to change.

  The present invention solves the above-described conventional problems, and can produce an induction heating coil having different coil characteristics by sharing a coil base. When changing the coil characteristics, the coil conductor is disposed in which part. An object of the present invention is to provide an induction heating coil that can be easily grasped.

  In order to solve the conventional problem, a coil conductor wire disposed between wall-shaped projecting portions that are wound a plurality of times in the radial direction and provided with a first interval in the radial direction, and a projecting portion are formed on the upper surface. An induction heating coil having a coil base for holding a coil lead wire, wherein the protrusions are formed on a plurality of concentric circles having different diameters around the center of the heating coil and having at least one notch. And a first interval having at least one set of protrusions radially spaced by a second interval wider than the first interval, and further having no coil conductor inside or outside the second interval. It was set as the structure which has the projection part separated by.

  As a result, since the coil conductor is not provided on the inner side or the outer side of the second interval, the protrusion is separated by the first interval, and thus the coil base is shared by disposing the coil conductor in that portion. Induction heating coils with different coil characteristics can be made.

  Since the induction heating coil of the present invention has projections separated by the first interval where the coil conductor is not provided on the inside or outside of the second interval, the coil conductor is disposed at that portion, so that the coil An induction heating coil having different coil characteristics can be manufactured by sharing the base.

  Furthermore, by having a set of protrusions radially separated by a second interval that is wider than the first interval, it is possible to easily grasp in which part the coil conductor is disposed when changing the coil characteristics. Can do.

  Further, since the protrusions are formed on the concentric circles, the coil conductors are arranged at the first interval between the protrusions, so that the coil conductors can be wound on the concentric circles, and one step in the vertical direction of the heating coil. It is also possible to wind one more stage on the roll. For this reason, it becomes possible to wind a sufficient number of turns to ensure heating performance in a limited space.

The perspective view of the induction heating coil in the 1st Embodiment of this invention The perspective view of the state which assembled the induction heating coil in the 1st Embodiment of this invention The perspective view of the state assembled by changing the winding method of the induction heating coil in the 1st Embodiment of this invention Sectional drawing of the induction heating coil in the 2nd Embodiment of this invention The perspective view of the induction heating coil in the 4th Embodiment of this invention Sectional view of a conventional induction heating cooker A top view of a conventional induction heating coil View of a conventional induction heating coil viewed from below The figure of the conventional induction heating coil described in patent document 1

A first invention is a coil conductor wire that is wound a plurality of times in the radial direction and disposed between wall-shaped projections having a first interval in the radial direction, and the projections are formed on the upper surface. An induction heating coil having a coil base for holding a conductive wire, wherein the protrusion is formed on a plurality of concentric circles having different diameters around the center of the heating coil, and has at least one notch, Having at least one set of protrusions radially spaced by a second spacing that is wider than one spacing, and further spaced by a first spacing in which no coil conductor is provided inside or outside the second spacing. It has a configuration having a protruding portion.

  As a result, since the coil conductor is not provided on the inner side or the outer side of the second interval, the protrusion is separated by the first interval, and thus the coil base is shared by disposing the coil conductor in that portion. Induction heating coils with different coil characteristics can be made.

  Furthermore, by having a set of protrusions radially separated by a second interval that is wider than the first interval, it is possible to easily grasp in which part the coil conductor is disposed when changing the coil characteristics. Can do.

  Further, since the protrusions are formed on the concentric circles, the coil conductors are arranged at the first interval between the protrusions, so that the coil conductors can be wound on the concentric circles, and one step in the vertical direction of the heating coil. It is also possible to wind one more stage on the roll. For this reason, it becomes possible to wind a sufficient number of turns to ensure heating performance in a limited space.

  In particular, according to a second invention, in the first invention, a plurality of stages of the coil conducting wires are wound around at least one of the first intervals.

  As a result, the coil conductor can be wound in a plurality of layers in the vertical direction of the heating coil, so that a sufficient number of turns can be wound in a limited space to ensure heating performance. The heating performance of the heating coil in the cooking device can be improved.

  In a third aspect of the invention, in particular, in the first or second aspect of the invention, the ferrite base is provided with a ferrite positioned below the coil conducting wire, the coil base has a ferrite holding portion for holding the ferrite, and a plurality of the protrusions are provided. The structure is provided on the upper surface of the ferrite holding portion.

  Thereby, by suppressing the area | region which provides a projection part, the area | region where the coil base is not provided under the coil conducting wire can be enlarged, cooling performance can be improved, and a heating coil can be cooled efficiently. Furthermore, since the amount of resin used for the coil base can be suppressed, the cost can be reduced.

  In a fourth aspect of the invention, in particular, in any one of the first to third aspects of the invention, a temperature detection element is provided between the second intervals.

  Thereby, when the temperature of the heating coil is high, the heating coil can be protected, and the quality of the heating coil can be improved. Moreover, by providing between 2nd space | intervals, a temperature detection element does not become a hindrance to a coil conducting wire, and it is easy to attach. Furthermore, since it is provided at the second interval, the presence or absence of the temperature detection element is easily understood.

  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 the induction heating coil according to the first embodiment of the present invention, FIG. 2 is a perspective view of the induction heating coil according to the first embodiment of the present invention assembled, and FIG. 3 is the present invention. The perspective view of the state assembled by changing the winding method of the induction heating coil in 1st Embodiment of this is shown.

  In FIG. 1, a heating coil (induction heating coil) 11 is formed on a plurality of concentric circles having different diameters around the center of the heating coil 11 on the upper surface of a resin-made coil base 12. The coil conductor 14 is fitted and wound between the wall-shaped protrusions 13 provided with the interval 15. In FIG. 1, the coil conductor 14 seems to be fixed in a wound state, but this is shown for easy understanding, and is wound by being fitted between the protrusions 13 as shown in FIG. 2. It is a configuration.

  Below the coil base 12, there is provided a ferrite 17 for efficiently transmitting magnetic lines of force generated from the coil conductor 14 to a pan (not shown) that is an object to be heated above the heating coil 11. There is no particular limitation on the direction in which the coil conductor 14 is wound, whether it is wound from the center of the heating coil 11 or wound from the outside. In FIGS. 1 and 2, as an example, the heating coil 11 is wound from the center toward the outside, and the winding direction is counterclockwise.

  The coil lead wire 14 fitted between the protrusions 13 is generally a copper wire, and differs depending on the induction heating cooker using the heating coil 11, but a wire having a diameter of about 0.2 mm to 0.5 mm is 30. It is composed of about 100 twisted pieces. The surface of the copper wire is covered with an insulator so that the respective wires are not electrically connected. Each strand is electrically connected at the start and end of the heating coil 11. The reason why such a thin wire is used as the coil wire of the heating coil 11 is that a high-frequency current having a frequency of about 20 to 30 kHz flowing through the heating coil 11 is concentrated on the surface of the coil wire due to the skin effect. This is because it is necessary to increase the surface area. The reason for twisting together is to prevent the current distribution flowing through the coil wire from becoming non-uniform due to the proximity effect that acts between the coil wires of the heating coil 11 due to the high-frequency magnetic field generated by the heating coil 11, and the heating coil. This is because current is prevented from concentrating on the surface of the heating coil 11 (on the heated object side) due to the proximity effect that acts between the heating element 11 and the heated object. The material of the coil conductor 14 is not limited to copper, and aluminum or the like may be used.

  As shown in FIGS. 1 and 2, the protrusion 13 is formed on a plurality of concentric circles having different diameters around the center of the heating coil 11, so the coil conductor 14 is fitted between the protrusions 13. The coil conducting wire 14 can be wound on a concentric circle, and it is also possible to wind one more stage on the heating coil 11 after further winding in the vertical direction.

  As shown in FIG. 2, in order to wind the coil conductor 14 concentrically, when the coil conductor 14 is wound in the horizontal direction of the heating coil 11 and then wound outward from the center, the coil conductor 14 is projected radially outward. Since the transition must be made to fit between the protrusions 13, the protrusion 13 has at least one notch for transition. If there is no notch and the protrusion 13 is connected in a circumferential shape, the coil conductor 14 cannot transition outward. By providing notches and forming a plurality of protrusions 13 on concentric circles, the coil conductor 14 can be wound in a plurality of layers in the vertical direction of the heating coil 11, so that heating performance is limited in a limited space. Since it is possible to wind a sufficient number of turns to ensure, the heating performance of the heating coil 11 in the induction heating cooker can be improved.

  FIG. 3 shows a state in which the coil conducting wire 14 is disposed on the same coil base 12 in the present embodiment in a manner different from that of FIG.

As shown in FIG. 2, in the present embodiment, there is at least one set of protrusions 13 that are radially separated by a second interval 16 that is wider than the first interval 15. The protrusions 13 are separated from each other by a first interval 15 where the coil conductor 14 is not provided on the inner side or the outer side. Thus, when the same coil base 12 is used and wound as shown in FIG. 2, the coil conductor 14 is disposed in the first interval 15 where the coil conductor 14 is not provided in FIG. Thus, the heating coil 11 having different coil characteristics can be produced using the same coil base 12. Furthermore, by making the second interval 16 wider than the first interval 15, it becomes easy to understand which portion is the portion where the coil conductor 14 is not provided. Further, by widening the second interval 16, the coil conductor 14 cannot be fitted even if it is mistakenly arranged, so that the arrangement cannot be made, leading to improvement in quality.

  With such a configuration, the coil conductor 14 is provided in the portion having the protrusion 13 separated by the first interval 15 where the coil conductor 14 is not provided inside or outside the second interval 16. Thus, the induction heating coil 11 having different coil characteristics can be produced by sharing the coil base 12.

  Further, by having a set of protrusions 13 that are radially separated by a second interval 16 wider than the first interval 15, it is easy to determine in which part the coil conductor 14 is disposed when changing the coil characteristics. Can grasp.

(Embodiment 2)
FIG. 4 shows a sectional view of the induction heating coil in the second embodiment of the present invention. Since the basic configuration of the present embodiment is the same as that of the first embodiment, different points will be mainly described. The same elements as those of the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

  In FIG. 4, the heating coil 11 of this embodiment has the protrusions 13 formed concentrically, so that the coil conductor 14 can be wound in a plurality of layers in the vertical direction of the heating coil 11. It is possible to wind only one layer or multiple layers at the first interval 15 between them. Thus, for example, it is possible to increase the number of turns of the coil by winding it all in two layers, and a region in which the necessary number of turns is determined by forming a part of a plurality of layers and another part of one layer. It becomes possible to wind it.

  With such a configuration, the coil conductor 14 can be wound in a plurality of layers in the vertical direction of the heating coil 11, so that a sufficient number of turns can be wound in a limited space to ensure heating performance. Therefore, the heating performance of the heating coil 11 in the induction heating cooker can be improved.

(Embodiment 3)
Since the basic configuration of the present embodiment is the same as that of the first embodiment, different points will be mainly described. The same elements as those of the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

  As shown in FIGS. 1 to 3, in this embodiment, the coil base 12 includes a ferrite holding portion 18 for inserting and holding the ferrite 17, and a plurality of protrusions 13 are provided on the upper surface of the ferrite holding portion 18. Is. The ferrite 17 may be held by an adhesive or a structure in which the coil base 12 is provided with claws. With the configuration as shown in the figure, since the area where the coil base 12 is not present becomes larger below the coil lead wire 14, the coil lead wire 14 can be efficiently cooled, so that the cooling performance of the heating coil 11 is improved. be able to. In addition, since the coil conductor 14 is fitted between the protrusions 13, the coil conductor 14 in the region where the coil base 12 does not exist below the notch is provided between the coil conductor 14 of the adjacent turn. Since there is a gap corresponding to the thickness of 13 and the coil conductor 14 has a gap between the lower surface and the adjacent turn, the surface area to which the cooling air is applied is large, and an efficient cooling configuration can be realized.

  With such a configuration, by suppressing the region where the protrusion 13 is provided, the region where the coil base 12 is not provided below the coil conductor 14 is enlarged, the cooling performance is improved, and the heating coil 11 is efficiently cooled. can do. Furthermore, since the amount of resin used for the coil base 12 can be suppressed, the cost can be reduced.

(Embodiment 4)
FIG. 5 shows a perspective view of an induction heating coil according to the fourth embodiment of the present invention. Since the basic configuration of the present embodiment is the same as that of the first embodiment, different points will be mainly described. The same elements as those of the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

  As shown in FIG. 5, in the present embodiment, the temperature detection element 19 is provided between the second intervals 16. As shown in the figure, the second interval 16 is provided near the center of the diameter of the heating coil 11. This is because when the pan is heated by the heating coil 11, the magnetic flux tends to concentrate near the center of the diameter of the heating coil 11 and the temperature tends to increase. The accuracy can be improved, and therefore the second interval 16 is provided in this portion. By providing the temperature detection element 19, it is possible to stop the heating when the temperature of the pan becomes abnormally high when the pan is abnormally heated, so that the safety of the user of the induction heating cooker can be secured. Moreover, since the temperature of the heating coil 11 becomes higher than the above and the heating coil 11 can be prevented from being damaged and the heating coil 11 can be protected, the quality of the induction heating cooker can be improved.

  Since the coil conductor 14 is not provided in the second interval 16, the provision of the temperature detection element 19 does not hinder the coil conductor 14. Further, the second interval 16 is wider than the first interval 15, and it is easy to confirm the presence or absence of the temperature detection element 19.

  Further, a first interval 15 that does not provide the coil conductor 14 is provided inside or outside the second interval 16, and by using these, the coil base 12 is shared, and the heating coil 11 having different coil characteristics is provided. When the two heating coils 11 are manufactured, the portions where the temperature rises are different, so that the accuracy can be further improved by providing a degree of freedom in the attachment position of the temperature detection element 19.

  With such a configuration, when the temperature of the heating coil 11 is high, the heating coil 11 can be protected, and the quality of the heating coil 11 can be improved. Moreover, by providing it between the 2nd space | interval 16, the temperature detection element 19 does not become the hindrance of the coil conducting wire 14, and is easy to attach. Furthermore, since the second interval 16 is provided, the presence or absence of the temperature detection element 19 is easily understood.

  As described above, the induction heating coil according to the present invention can wind a sufficient number of turns to ensure heating performance in a limited space. Applicable to usage.

11 Heating coil (Induction heating coil)
12 Coil Base 13 Projection 14 Coil Conductor 15 First Interval 16 Second Interval 17 Ferrite 18 Ferrite Holding Portion 19 Temperature Sensing Element

Claims (4)

A coil conductor wire that is wound a plurality of times in the radial direction and is disposed between wall-like projection portions that are first spaced in the radial direction, and the projection portion is formed on the upper surface to hold the coil conductor wire An induction heating coil including a coil base, wherein the protrusion is formed on a plurality of concentric circles having different diameters around the center of the heating coil, and has at least one notch, The first gap has at least one set of the protrusions radially separated by a second gap wider than the gap, and the coil conductor is not provided inside or outside the second gap. An induction heating coil having the protrusions separated by each other. The induction heating coil according to claim 1, wherein the coil conductor wire is wound in a plurality of stages at at least one or more of the first intervals. The ferrite according to claim 1 or 2, comprising a ferrite positioned below the coil conducting wire, wherein the coil base has a ferrite holding portion for holding the ferrite, and a plurality of the protrusions are provided on an upper surface of the ferrite holding portion. Induction heating coil. The induction heating coil according to any one of claims 1 to 3, wherein a temperature detection element is provided between the second intervals.