JP2016157590A - Electromagnetic induction heating coil and electromagnetic induction heating cooker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electromagnetic induction heating coil and an electromagnetic induction heating cooker that can prevent disturbance of magnetic flux occurring in a coil and heat a heating target object uniformly and has high efficiency.SOLUTION: An electromagnetic induction heating coil includes a first layer coil in which a winding is spirally wound from the outer periphery to the inner periphery, a second layer coil in which a winding is spirally would subsequently from the innermost periphery of the first layer coil in the same direction to the outer periphery, and a pair of outgoing lines which are drawn out from the outermost peripheries of the first layer coil and the second layer coil and supply power to the first layer coil and the second layer coil.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an electromagnetic induction heating coil that generates a magnetic flux by an electric current passed through the coil and electromagnetically heats an object to be heated by the magnetic flux, and an electromagnetic induction heating cooker using the electromagnetic induction heating coil.

  2. Description of the Related Art Conventionally, coils that are wound in a spiral on the same plane have been widely used as electromagnetic induction heating coils (hereinafter sometimes simply referred to as “coils”). In such a coil, the space on the inner diameter side of the coil (where the coil is not wound) serves as a path for magnetic flux, so that an appropriate space, that is, the inner diameter of the coil is required. The ratio of the outermost circumference length and the innermost circumference length of the coil for securing this space is the outermost circumference length / the innermost circumference length = 3 or less, preferably 2.5 or less.

  However, the outer diameter of the coil is constrained by the outer diameter of the object to be heated, and the inner diameter of the coil cannot be increased due to the number of turns and the load matching relationship with the high-frequency power source. For this reason, the ratio of the outermost circumference length / the innermost circumference length often exceeds 3. In such a case, the magnetic flux density in the space on the inner diameter side of the coil is abnormally higher than the magnetic flux density in the vicinity of the object to be heated. And the magnetic flux which cannot pass has been forced to pass through the spiral coil close to the coil inner diameter space, leading to an increase in coil temperature and a decrease in heating efficiency.

  For this reason, for the purpose of suppressing the temperature rise of the coil and obtaining an inductance suitable for electromagnetic induction heating of the load, JP 2000-340352A is laminated with a plurality of coils, and these coils are connected in series. Thus, there is disclosed an electromagnetic induction heating device that can increase the number of turns of the entire coil, or can be connected in parallel to make a necessary number of turns with a thin wire diameter coil. And in order to supply electric power to these coils, a pair of leader line is provided in the both ends of the coil.

JP 2000-340352 A

  However, in the conventionally employed electromagnetic induction heating coil and the coil described in Patent Document 1, one lead wire 116a is provided on the outermost periphery of the coil 701 as shown in FIG. The other lead wire 116b is provided on the innermost circumference of the coil 701, and is drawn out so as to cross the winding around the coil. For this reason, the magnetic field generated from the lead wire causes the magnetic field generated from the coil to be confused, which reduces the heating efficiency and makes it difficult to uniformly heat the object to be heated.

  The present invention has been made in view of the above points, and by providing a pair of lead wires on the outermost periphery of the coil, the lead wire is configured not to cross the coil winding, thereby generating magnetic flux in the coil. It is an object of the present invention to provide an electromagnetic induction heating coil and an electromagnetic induction heating cooker that can prevent the disturbance of heat and can efficiently heat an object to be heated.

The electromagnetic induction heating coil of the present invention is
A first layer coil in which the winding is spirally wound from the outer periphery toward the inner periphery;
A second layer coil in which a winding is wound spirally in the same direction and toward the outer periphery continuously from the innermost periphery of the first layer coil;
A pair of lead wires that are drawn from the outermost circumference of the first layer coil and the second layer coil and supply power to the first layer coil and the second layer coil;
It is characterized by providing.

  According to the electromagnetic induction heating coil of the present invention, the first layer coil in which the winding is spirally wound from the outer periphery toward the inner periphery, and the same direction and toward the outer periphery continuously from the innermost periphery of the first layer coil. Since the first layer coil and the second layer coil are connected in series, and both ends of these coils are provided on the outermost periphery of the coil. Become. Thereby, the lead line which supplies electric power to a 1st layer coil and a 2nd layer coil is pulled out from the outermost periphery of these coils. For this reason, the lead wire does not cross the winding, and the magnetic flux generated in the coil is not disturbed by the lead wire. Further, since the coil has two layers, the ratio of the outermost circumference length to the innermost circumference length can be easily set to 3 or less. The winding of the second layer coil in the same direction as the winding of the first layer coil means that the direction of the current is the same in the winding of the second layer coil and the winding of the first layer coil. Is intended to be wound as

A preferred example of the electromagnetic induction heating coil of the present invention is:
The windings of the first layer coil and the individual windings of the second layer coil form a set of windings that are stacked in a direction perpendicular to the surfaces of the first layer coil and the second layer coil. It is characterized by being.

  According to a preferred example of the electromagnetic induction heating coil of the present invention, the windings of the first layer coil and the individual windings of the second layer coil are overlapped to form a set of windings. Are generated so that the magnetic flux extends in the direction in which the windings are overlapped. Thereby, the magnetic flux easily reaches the object to be heated, and the object to be heated can be heated more efficiently.

A preferred example of the electromagnetic induction heating coil of the present invention is:
A gap is provided between the pair of adjacent windings.

Moreover, the preferable example of the electromagnetic induction heating coil of this invention is:
The spaced distance between the pair of adjacent windings is more than 1 times the diameter of the windings and 1.5 times or less as the inter-axis distance of the windings.

  According to these preferable examples of the electromagnetic induction heating coil of the present invention, the coil is a coarse winding having a gap between one set of windings and another set of adjacent windings. A wide range can be heated. Moreover, since it becomes difficult to receive the influence of the magnetic flux of other adjacent windings, the magnetic flux is emitted so as to extend further in the direction in which the windings are overlapped. Moreover, the freedom degree of the ratio of outermost periphery length and innermost periphery length can be increased. As a result, the object to be heated can be heated more efficiently.

A preferred example of the electromagnetic induction heating coil of the present invention is:
The set of windings is inclined toward the inner peripheral side.

Moreover, the preferable example of the electromagnetic induction heating coil of this invention is:
The inclination angle is not less than 60 degrees and less than 90 degrees with respect to the surface direction of the first layer coil and the second layer coil.

  According to these preferred examples of the electromagnetic induction heating coil of the present invention, since the set of windings is inclined toward the inner peripheral side of the coil, the direction in which the magnetic flux is radiated is also on the inner peripheral side of the coil. Can be tilted. Thereby, a to-be-heated object can be heated also in the center part of the coil in which no winding exists. In addition, even if the surface of the object to be heated facing the electromagnetic induction heating coil is convex toward the electromagnetic induction heating coil and the distance between the coil and the object to be heated is increased on the outer peripheral side of the coil, the magnetic flux Can easily reach the object to be heated, and the object to be heated can be efficiently heated.

A preferred example of the electromagnetic induction heating coil of the present invention is:
The angle of inclination is configured such that the inner peripheral side is larger than the outer peripheral side of the set of windings,
The angle of inclination of the set of windings on the outermost periphery is 60 degrees or more with respect to the surface direction of the first layer coil and the second layer coil,
An inclination angle of the pair of windings on the innermost circumference is 90 degrees or less with respect to a surface direction of the first layer coil and the second layer coil.

  According to a preferred example of the electromagnetic induction heating coil of the present invention, the set of windings on the outer peripheral side is strongly inclined, and the set of windings on the inner peripheral side becomes upright or close to upright. For this reason, the direction in which the magnetic flux is emitted can be changed for each set of windings, and the degree of freedom in design increases. In addition, even in a heated object having a convex surface facing the coil, a set of windings are substantially perpendicular to the surface of the object to be heated over almost the entire surface of the object, so that the magnetic flux is efficiently Acts on the object to be heated.

A preferred example of the electromagnetic induction heating coil of the present invention is:
The third layer is wound in the same direction continuously from the outermost periphery of the first layer coil or the second layer coil, and the winding is wound on only the outermost periphery of the first layer coil or the second layer coil. A coil,
One of the lead wires is drawn from the outermost periphery of the first layer coil or the second layer coil, and the other lead wire is drawn from the third layer coil.

  According to the preferred example of the electromagnetic induction heating coil of the present invention, since the third layer coil is provided at the outermost periphery of the coil, the magnetic flux in the part becomes stronger and stronger in the superimposed direction. Magnetic flux can be radiated. As a result, the object to be heated can be heated more efficiently in the outer peripheral portion where the distance from the object to be heated is easily separated.

The electromagnetic induction heating cooker of the present invention is
Any of the electromagnetic induction heating coils described above;
A power supply for supplying power to the electromagnetic induction heating coil;
A top plate provided above the electromagnetic induction heating coil for placing an object to be heated;
It is characterized by providing.

  According to the electromagnetic induction heating cooker of this invention, there can exist an effect similar to the electromagnetic induction heating coil mentioned above.

  As described above, according to the electromagnetic induction heating coil and the electromagnetic induction heating cooker of the present invention, the pair of lead wires are provided on the outermost periphery of the coil so that the lead wires do not cross the coil winding. Thus, the disturbance of the magnetic flux generated in the coil can be prevented, and the object to be heated can be heated uniformly with high efficiency.

It is a figure which illustrates typically the electromagnetic induction heating coil which concerns on one Embodiment of this invention. It is a figure which illustrates typically the other example of the electromagnetic induction heating coil of this invention. It is the BB line end elevation of the electromagnetic induction heating coil shown in FIG. It is a figure explaining the further another example of the electromagnetic induction heating coil of this invention. It is a figure explaining the further another example of the electromagnetic induction heating coil of this invention. It is a figure explaining the further another example of the electromagnetic induction heating coil of this invention. It is a figure explaining the further another example of the electromagnetic induction heating coil of this invention. It is a figure explaining the state which is heating the to-be-heated object with the electromagnetic induction heating cooking appliance of this invention. It is a figure explaining an example of the appearance of the electromagnetic induction heating cooking appliance concerning one embodiment of the present invention. It is a figure which illustrates the conventional electromagnetic induction heating coil typically. It is a figure which shows the specification of the apparatus used for the heating experiment of the electromagnetic induction heating coil which concerns on one Embodiment of this invention. It is a figure which shows the data which concern on the coil characteristic and heating characteristic of an electromagnetic induction heating coil. It is a figure which shows the data which examines the characteristic of an electromagnetic induction heating coil from the data shown in FIG. It is another figure which shows the data which investigates the characteristic of an electromagnetic induction heating coil from the data shown in FIG. It is another figure which shows the data which investigates the characteristic of an electromagnetic induction heating coil from the data shown in FIG. It is a figure which compares the heating trace by the conventional electromagnetic induction heating coil, and the heating trace by the electromagnetic induction heating coil which concerns on one Embodiment of this invention.

  Hereinafter, an electromagnetic induction heating coil and an electromagnetic induction heating cooker according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. In addition, the electromagnetic induction heating coil of this invention is incorporated and used for the electromagnetic induction heating cooking appliance of this invention.

  First, with reference to FIG. 9, the electromagnetic induction heating cooking appliance which concerns on one Embodiment of this invention is demonstrated. FIG. 9 is a diagram illustrating an example of the appearance of an electromagnetic induction heating cooker according to an embodiment of the present invention.

  As shown in FIG. 9, the electromagnetic induction heating cooker 20 of this embodiment is a built-in type that is provided in another cooking facility, and includes a main body portion 21 and an operation portion 31. The main body 21 includes a top plate 22 for placing an object to be heated, a casing 23 provided with a ventilation hole for cooling, and an electromagnetic induction according to an embodiment of the present invention inside the casing 23. A heating coil, a power supply unit (not shown) that supplies a high-frequency current to the electromagnetic induction heating coil, a cooling fan, a ferrite disposed below the electromagnetic induction heating coil, a coil base that holds the electromagnetic induction heating coil, and the like are provided. .

  The operation unit 31 is for operating the electromagnetic induction heating cooker 20 and is connected to the main body unit 21 by a cable 32, and includes a power switch 33, an output adjustment knob 34, an indicator 35, and the like. The main body 21 is provided with a power line 25 for supplying power from a commercial power source.

  As the power supply unit, a known unit generally used for an electromagnetic induction heating cooker is adopted, a rectifier circuit that rectifies AC of a commercial power source into DC, a direction of current flowing through the electromagnetic induction coil while intermittently rectifying the DC. And a control unit (none of which is shown) for controlling the switching element. Note that the electromagnetic induction heating cooker is not limited to the built-in type, and may be various types such as a stationary type and a portable type.

  Next, an electromagnetic induction heating coil according to an embodiment of the present invention will be described with reference to FIGS. 1A to 1C are diagrams schematically showing a coil for explaining an electromagnetic induction heating coil according to an embodiment of the present invention, and FIG. 1A is a first layer coil, FIG. 1 (B) is a second layer coil, and FIG. 1 (C) is a diagram in which the first layer coil and the second layer coil are superimposed. FIGS. 2A to 2C are diagrams schematically showing the coil as in FIG. 1 for explaining another example of the electromagnetic induction heating coil of the present invention. 3 is an end view taken along line BB of the electromagnetic induction heating coil shown in FIG. 2C. FIG. 4 is a diagram for explaining another example of the electromagnetic induction heating coil of the present invention from the same cross section as FIG. FIG. 7 is a view for explaining still another example of the electromagnetic induction heating coil of the present invention.

  As shown in FIGS. 1A and 1B, the electromagnetic induction heating coil 101 of this embodiment includes a first layer coil 111 and a second layer coil 112. The first layer coil 111 is a spiral coil in which a winding is wound spirally from the outer periphery toward the inner periphery. The second layer coil 112 is a spiral coil in which the winding is wound in the same direction as the first layer coil 111 from the inner periphery toward the outer periphery. Then, as shown in FIG. 1C, the innermost end 15a of the first layer coil 111 and the innermost start 14b of the second layer coil 112 are connected, and both coils are overlapped. A two-layer coil 101 connected in series is configured. A pair of lead wires 16a and 16b for supplying power to these coils are connected to the start end 14a on the outermost periphery of the first layer coil 111 and the end 15b on the outermost periphery of the second layer coil 112. . With this configuration, the lead wires 16a and 16b do not cross the coil winding, and the magnetic force generated by the lead wires 16a and 16b does not disturb the magnetic flux generated by the coil. Moreover, the lead wires 16a and 16b can be made to be in a state in which the adverse effect on the coil can be substantially ignored by twisting each other.

  The current flows in the same direction in the first layer coil 111 and the second layer coil 112 as indicated by arrows in the figure. In addition, the first layer coil 111, the second layer coil 112, and the pair of lead wires 16a and 16b are formed by using a litz wire in which a plurality of thin enamel wires are twisted, and each of them is a single litz wire. Can be configured. 1A to 1C are diagrams schematically showing the first layer coil 111 and the second layer coil 112. In the drawing, the first layer coil 111 and the second layer coil 112 are shown. In order to make the configuration easy to understand, the adjacent windings are drawn roughly so as to have a gap, but in an actual product, the number of turns and the gap between the windings can take various forms.

  Further, in the electromagnetic induction heating coil 101 shown in FIG. 1C, the first layer coil 111 and the second layer coil 112 overlap as surfaces, but individual windings are orthogonal to the surface of the coil. It is only in the vicinity of the line A-A in the figure that is superimposed in the direction and forms a set of windings.

  Next, another example of the electromagnetic induction heating coil 201 will be described with reference to FIGS. The first layer coil 211 shown in FIG. 2A is a spiral coil in which the winding is spirally wound from the outer periphery toward the inner periphery, and the second layer coil 212 shown in FIG. Is a spiral coil in which the winding is spirally wound in the same direction as the first layer coil 211 from the outer periphery to the outer periphery. As shown in FIG. 2C, when the first layer coil 211 and the second layer coil 212 are two-layer electromagnetic induction heating coil 201 by overlapping the coils, the locus of the winding of each other coil is used. The part which does not fit is used as the crossing part P, and is bent into a straight line. In the crossing portion P, the first layer coil 211 is bent from the lower left to the upper right, and the second layer coil is bent from the lower right to the upper left. By providing such a crossover portion P, the first layer coil 211 and the second layer coil 212 overlap each other in a direction perpendicular to the surface of the coil to form a set of windings. In addition, at the transition portion P, the winding of the first layer coil 211 and the winding of the second layer coil 212 intersect in an X shape to prevent magnetic flux confusion at the transition portion P. it can.

  The electromagnetic induction heating coil 201 in which the individual windings are stacked in a direction orthogonal to the coil surface will be further described with reference to FIG. FIG. 3 is an end view taken along line BB in FIG. 2C and an enlarged view of a part thereof. As already described, in this electromagnetic induction heating coil 201, individual windings are stacked in a direction orthogonal to the plane of the coil, and each stacked winding forms a set of windings OS1. As shown in the enlarged view in the circle in the figure, this is the central axis of the winding on the heated object side (upper winding) and the winding on the opposite side of the heated object (lower winding) That is, they are on a conceptual line L1 in a direction perpendicular to the surface of the coil. By doing so, the magnetic fluxes of the individual windings are combined and radiated so that the magnetic flux extends long in the direction orthogonal to the coil surface, that is, the direction of the heated object, and efficiently heats the heated object. can do. In the electromagnetic induction heating coil 201, the distance between the central axes of a pair of adjacent windings OS1, that is, the winding pitch P1, is substantially the same as the diameter (2r) of the winding.

  Next, still another example of the electromagnetic induction heating coil will be described with reference to FIG. FIG. 4 is an end view of the electromagnetic induction heating coil 301 cut at the same position and angle as FIG. 3 and an enlarged view of a part thereof. As shown in FIG. 4, this electromagnetic induction heating coil 301 is composed of a set of windings OS <b> 2 composed of a first layer coil 311 and a second layer coil 312 that are spirally configured and stacked, and another set of adjacent windings OS <b> 2. The winding is a coarse winding having a gap S1 between the winding OS2. By using the coarse winding in this way, the magnetic flux φ generated in the pair of windings OS2 is less affected by the magnetic fluxes of other adjacent windings, and the magnetic flux φ is more overlapped with the windings. The object to be heated can be heated more efficiently. In addition, the surface of the coil itself can be enlarged while keeping the winding length the same, and a wide range can be heated, and the degree of freedom in adjusting the ratio of the outermost circumference length to the innermost circumference length of the coil is increased. Can be efficiently heated.

  The spacing distance between a pair of adjacent windings OS2 is preferably 1.5 times (3r) or less and more than 1 time (2r) of the diameter of the winding in the distance between the axes of the windings. The separation distance between a pair of adjacent windings OS2 of the electromagnetic induction heating coil 301 is configured to be 1.5 times (3r) the diameter of the winding. This is because if the distance between the pair of windings OS2 is too large, the magnetic flux density with respect to the object to be heated tends to decrease, and the heating efficiency of the coil tends to deteriorate.

  Next, still another example of the electromagnetic induction heating coil will be described with reference to FIG. FIG. 5 is an end view of the electromagnetic induction heating coil 401 cut at the same position and angle as FIG. 3 and an enlarged view of a part thereof. As shown in FIG. 5, this electromagnetic induction heating coil 401 is composed of a pair of windings OS3 each composed of a first layer coil 411 and a second layer coil 412 that are superposed on each other with a winding diameter of 1 at the distance between the axes. It is spaced apart by 5 times (3r), and is inclined toward the inner periphery to have a substantially C-shaped cross section. Thus, by separating the set of windings OS3 and inclining toward the inner periphery of the coil, as shown in the enlarged view, the magnetic flux φ generated in the set of windings OS3 is changed to the object to be heated. The object to be heated can be heated even in a place where there is no winding, such as the central part of the coil. Moreover, the surface (bottom surface) facing the electromagnetic induction heating coil 401 of the object to be heated is convex toward the electromagnetic induction heating coil 401, and the distance between the coil and the object to be heated is the outer periphery of the object to be heated. Even if they are separated, the magnetic flux is radiated toward the center of the bottom surface of the object to be heated, so that the magnetic flux easily reaches the object to be heated.

  The angle α1 for inclining the pair of windings OS3 is preferably 60 degrees or more and less than 90 degrees with respect to the surface direction of the first layer coil 411 and the second layer coil 412, and 70 degrees or more and 80 degrees. Less than degree is more preferable. This is because if the inclination is too strong (the angle is small), the upper winding of the set of windings OS3 contacts the lower winding of the other set of windings OS3 adjacent to the inside. This is because the magnetic flux is hardly emitted toward the upper side and the inner peripheral side due to the influence of the magnetic fluxes of other adjacent windings. In addition, although it is said inclination | tilt angle, when the clearance gap S2 between one set of winding OS3 is narrow, it is desirable to set it as the range which 60 to 90 degree and adjacent windings do not contact.

  In addition, as shown in FIG. 6, an electromagnetic induction heating coil 4011 in which the angles α2 and α3 for inclining the pair of windings OS4 can be changed between the outer peripheral side and the inner peripheral side of the coil. The electromagnetic induction heating coil 4011 is configured to gradually increase as the inclination angle of the pair of windings OS4 becomes the inner peripheral side, and the angle α2 of the innermost set of windings OS4 becomes the first layer coil 4111 and the first layer coil 4111. The angle is 90 degrees with respect to the surface direction of the two-layer coil 4121. In the coil, the inclination angle α3 of the pair of windings OS4 on the outermost periphery is preferably 60 degrees or more. In this way, by changing the angle at which the set of windings OS4 is inclined, the magnetic flux radiated from the set of windings OS4 provided on the outermost periphery of the coil is directed toward the inner periphery of the coil. Magnetic flux radiated from a set of windings OS4 provided on the inner periphery is radiated substantially perpendicularly to the surface of the coil. This makes it easier for the magnetic flux to reach the heated object even if the coil and the heated object are separated from each other on the outer periphery of the heated object, and the coil surface and the heated object surface are on the inner peripheral side of the coil. In a parallel place, the set of windings OS4 is at a right angle or near a right angle to the object to be heated, and the magnetic flux can be efficiently radiated to the object to be heated. Further, even in a coil in which the ratio of the outermost circumference length to the innermost circumference length is relatively large and there is not much space on the inner diameter side of the coil, the magnetic flux density in the space on the inner diameter side of the coil does not become higher than necessary. . The electromagnetic induction heating coil 4011 is configured to gradually increase as the inclination angle of the pair of windings OS4 becomes the inner peripheral side, but the set of windings corresponding to several turns from the outer peripheral side of the coil is inclined. In addition, the set of windings on the inner circumferential side can all be 90 degrees.

  Next, still another example of the electromagnetic induction heating coil will be described with reference to FIGS. 7A and 7B are end views of the electromagnetic induction heating coils 501 and 601 cut at the same position and angle as in FIG. As shown in FIGS. 7A and 7B, these electromagnetic induction heating coils 501 and 601 include third layer coils 513 and 613 on the outermost periphery. This is realized by winding in the same direction continuously from the outermost periphery of the second layer coils 512 and 612, and further winding the winding only on the outermost periphery of the second layer coils 512 and 612. In addition, in these electromagnetic induction heating coils 501, 601, one lead wire 16a for supplying power to the coil is connected to the outermost periphery of the first layer coils 511, 611, and the other lead wire 16b is the third layer coil 513. , 613. In this way, the magnetic flux is further radiated more strongly in the vertical direction at the outermost periphery of the coil, and the heated object is effectively heated even when the distance between the coil and the heated object is large at the outer periphery of the heated object. can do.

  Next, with reference to FIGS. 11 to 15, data of a comparative experiment between the conventional electromagnetic induction heating coil and the electromagnetic induction heating coil of the present embodiment will be described. FIG. 11 is a table describing the specifications of the measuring equipment and inverter power supply used in the experiment, FIG. 12A is a table describing the structure of the electromagnetic induction heating coil and the coil characteristics at no load, and FIG. It is the table | surface which described the coil characteristic and heating characteristic when supplying with electricity to the electromagnetic induction heating coil. 13 to 15 are tables in which the characteristics of the electromagnetic induction heating coil are examined from the values shown in FIG.

  In addition, although it is an electromagnetic induction heating coil shown in these tables, no. No. 1 was drawn so that one of the conventional lead wires crossed the coil winding from the innermost circumference of the coil. No. 2 is an electromagnetic induction heating coil according to this embodiment having a winding pitch of 2r shown in FIG. No. 3 is an electromagnetic induction heating coil according to the present embodiment, in which the winding pitch of the coil shown in FIG. Reference numeral 4 denotes an electromagnetic induction heating coil according to the present embodiment, in which the winding pitch of the coil shown in FIG. 5 is 4r, and the inclination angle of the pair of windings is 75 degrees.

  In this experiment, an electromagnetic induction heating coil was placed on a wooden table, a ceramic spacer was placed on the coil, and a flat bottom pan made of SUS430 was placed on top of that with 1 liter of water. The water was heated using the inverter power source shown in FIG. And while stirring water when heating, temperature was measured with the thermometer shown in FIG. 11, and the time which the water temperature of about 15 degreeC rises to 50 degreeC was measured with the stopwatch shown in FIG. As a result, the values shown in FIG. 12 (B) were obtained.

  Next, the characteristics of these electromagnetic induction heating coils are examined from the values shown in FIG. First, in the row of “coil characteristics” in the table of FIG. The ratio (value 1 ') of the respective measured impedance (value 1 (row)) and the ratio of the measured inductance (value 2) are obtained (value 2') with reference to the two coils. Then, the ratio of the measured impedance and the measured inductance in each coil is substantially the same, and it can be seen that the coil with the coil winding pitch of 2r and the coil of 4r have a substantially constant ratio.

  Next, in the row of “heating characteristics” in the table of FIG. 13, the calculated inverter power input power is calculated from the actually measured inverter power (INV) input voltage (value 3) and the actually measured inverter power input current (value 4). (Value 5). Further, the calculated inverter power supply output power (value 7) is obtained from the actually measured inverter power supply output current (value 6) and the measured impedance (value 1). In addition, when calculating | requiring these values, unless there is particular description, the formula described in each column of the table | surface in a figure is used.

Next, in the row of “coil characteristics” in the table of FIG. 3 and no. The coil characteristics when the winding pitch of the coil No. 4 is reduced from 4r actually tested to 3r which is a virtual dimension will be examined. The impedance ratio (value 1 ′) indicates that there is a correlation between the coil winding pitch dimension and the impedance. 3 and no. Calculated impedance (value 1 ″) when the winding pitch of coil 4 is 3r
Where Zc is the calculated impedance and Z is the measured impedance.
Further, based on the calculated impedance (value 1 ″) obtained by the above formula, NO. The ratio of the calculated impedance (value 1 ″) is obtained (value 1 ′ ″) using the measured impedance (value 1) of the coil 2 as a reference.

  Next, in the row of “heating characteristics” in the table of FIG. 3 and no. The calculation of the inverter power supply output power when the winding pitch of the coil No. 4 is 3r and the value obtained by converting the calculated inverter power supply output power so that the current flowing through the coil is the same are calculated. First, the measured inverter power supply output current (value 6) 1 and No. The coil No. 2 has an actually measured impedance (value 1). 3 and no. The coil No. 4 calculates the calculated inverter power supply output power (value 7 ') with the calculated impedance (value 1 ").

  Next, the calculated inverter power supply output power (value 7 ″) at the converted inverter power supply output current (value 6 ′) in which the measured inverter power supply output current (value 6) is all 16 amperes is set to No. 1 and No. The coil No. 2 has an actually measured impedance (value 1). 3 and no. The coil No. 4 is obtained with a calculated impedance (value 1 ″).

Next, in the table of FIG. 15, the temperature rise time when water is heated is obtained from the calculated inverter power supply output power (value 7 ″). First, since there is variation in the 1 liter temperature rise amount (value 8 in FIG. 12B), the water 1 liter temperature rise amount in all coils is unified to Δ35 ° C. (value 8 ′ in FIG. 15). Next, an adjustment value (value 9 ′ in FIG. 15) of the water 1 liter temperature increase time (FIG. 12 (B) value 9) by unifying the water 1 liter temperature increase amount to Δ35 ° C. is expressed by the following equation.
(Where t ′ is a value 9 ′, ΔT ′ is 35 ° C., ΔT is a value 8, and t is a value 9).

Next, 1 liter of water temperature rise time (value 9 ') when the temperature increase amount is unified to 35 ° C, calculated inverter power supply output power (value 7) with measured inverter power supply output current (value 6), current Calculated with the converted inverter power supply output current (value 6 '), which is all 16 amps, and the inverter power supply output power (value 7''), the current flowing through all the coils increased to 1 liter of water when the current was 16 amps Time (value 9 ''')

(Where t ′ ″ is a value 9 ′ ″).

  Then, from the value 6 'and the value 7 ", no. No. 1 compared to coil No. 1. No. 2 coil can jump through and high output can be obtained. 3 and no. It can be seen that the No. 4 coil can obtain a slightly higher output. In addition, the temperature increase time for 1 liter of water from the value 9 '' ' No. 2 coil jumps through quickly, no. 3 and no. No. 4 coil is no. It is equivalent to 1 coil. From these, it can be seen that among the electromagnetic induction heating coils according to the present embodiment, a coil having a winding pitch between 2r and 3r has high output and high efficiency.

In addition, No. 3 coil and No. 3 coil. Considering the efficiency when the winding pitch of the coil 4 is r4, when the current value is 16 amperes, the calculated inverter power supply output power is obtained by 16 × 16 × impedance, which is 0.96 kW and 0.93 kW respectively . From this value, the water 1 liter heating time (value 9 ″)

(Where t ″ is the value 9 ″ and p is the calculated inverter power output power of r4).
As a result, each water 1 liter heating time (value 9 ″) was 196 seconds and 194 seconds. Compared with the coil of 1, it becomes slow.

  Next, with reference to FIGS. 8A to 8C, an operation when heating an object to be heated in an electromagnetic induction heating cooker incorporating an example of the electromagnetic induction heating coil of the present embodiment will be described. FIGS. 8A to 8C are diagrams illustrating a state in which the object to be heated is heated by the electromagnetic induction heating cooker of the present invention, and are end views of the electromagnetic induction heating cooker and the object to be heated. In addition, the to-be-heated material described in this figure assumes a pan whose bottom surface bulges downward in a convex shape and whose bottom outer edge is curved. Moreover, the arrow in a figure has shown the direction where magnetic flux is radiated | emitted.

  FIG. 8A shows the electromagnetic induction heating cooker 20 incorporating the electromagnetic induction heating coil 401 shown in FIG. 5, which includes the electromagnetic induction heating coil 401, the ferrite 24, and the top plate 22, and further includes a power source (not shown). Parts. Here, when a high-frequency current is passed through the electromagnetic induction heating coil 401, a magnetic flux is generated in each winding. And since a leader line does not cross the coil | winding of a coil, there is no disorder in the magnetic flux which generate | occur | produces in a coil, and the to-be-heated material 40 can be heated uniformly and highly efficiently. Also, as described above, this magnetic flux is radiated toward the upper side and the inner circumference side of the coil, so that the center part of the coil without winding or the outer circumference side where the distance between the heated part 40 and the winding is separated The magnetic flux reaches the object to be heated 40 and the object to be heated 40 can be efficiently heated.

  FIG. 8B shows an electromagnetic induction heating cooker 20 incorporating the electromagnetic induction heating coil 501 shown in FIG. 7A, and the configuration of the electromagnetic induction heating cooker 20 is the same as described above. Here too, an advantageous effect is exhibited by the fact that the lead wire does not cross the coil winding. Moreover, since each winding is piled up and down, the magnetic flux of the piled winding is put together and magnetic flux is radiated | emitted toward the upper side. Thereby, the magnetic flux easily reaches the object to be heated 40, and the object to be heated 40 can be efficiently heated. In addition, since the windings are stacked in three layers on the outermost periphery, the magnetic flux is more strongly radiated upward at the place. Thereby, magnetic flux reaches the to-be-heated object 40 also on the outer peripheral side where the distance between the to-be-heated part and the winding is long, and the to-be-heated object 40 can be efficiently heated.

  FIG. 8C shows the electromagnetic induction heating cooker 20 incorporating the electromagnetic induction heating coil 601 shown in FIG. 7B, and the configuration of the electromagnetic induction heating cooker 20 is the same as described above. Here too, an advantageous effect is exhibited by the fact that the lead wire does not cross the coil winding. In addition, this electromagnetic induction heating cooker has the advantages of FIGS. 8A and 8B, and the magnetic flux is radiated toward the upper side and the inner side of the coil. Magnetic flux can be emitted more strongly. Thereby, the to-be-heated material 40 can be heated more efficiently also in both the center side and outer peripheral side of a coil.

  In addition, in FIG. 8, although the effect | action of the electromagnetic induction heating coil shown in FIGS. 1-3 is not demonstrated, since it is a coil excellent in heating efficiency as already stated, it has the outstanding performance in normal use. It is clear that it works.

  Moreover, although different from the pan used in the above-described experiment, as shown in FIG. 16 (A), when heating with a conventional electromagnetic induction heating coil, uneven heating occurs, and particularly when the output is high, abnormal heating traces appear in the pan. There was something that remained. This is because in the conventional electromagnetic induction heating coil as described above, the leader wire crosses the winding of the coil, so that the leader wire disturbs the magnetic flux generated by the coil and causes uneven heating. On the other hand, as shown in FIG. 16B, in the electromagnetic induction heating coil according to this embodiment, the lead wire does not disturb the magnetic flux generated from the coil and is heated substantially uniformly.

  As described above, according to the electromagnetic induction heating coil and the electromagnetic induction heating cooker of the present embodiment, since the lead wire is provided on the outermost periphery of the coil, the lead wire does not cross the coil winding, The object to be heated can be heated uniformly without disturbing the magnetic flux generated in the coil by the lead wire. Moreover, high output can be obtained while the same current as that of the conventional electromagnetic induction heating coil, and coil loss and circuit loss can be reduced. Moreover, by making the coil into two layers, the ratio of the outermost circumference length and the innermost circumference length of the coil can be made appropriate while obtaining the necessary number of turns, and the magnetic flux is coiled on the inner circumference side of the coil. The winding itself is not heated. Furthermore, by twisting the two lead wires, it is possible to make a state in which the adverse effect of the lead wires on the coil can be substantially ignored.

  In addition, by using a coarse winding that provides a gap between adjacent windings, the magnetic flux is strongly emitted in the vertical direction, and the object to be heated can be heated more efficiently, and the width of the gap is adjusted. This makes it easy to adjust the ratio between the outermost circumference and the innermost circumference of the coil.

  In addition, a configuration in which a pair of windings composed of the stacked first layer coil and second layer coil is inclined toward the inner periphery of the coil, so that the magnetic flux can be radiated toward the inner periphery of the coil. it can. Accordingly, diffusion of magnetic flux on the coil outer periphery side is suppressed, the bottom outer edge portion is curved, and even a heated object whose bottom portion is convex downward can be efficiently heated.

  In addition, by tilting a set of windings on the outer peripheral side of the coil toward the inner peripheral side and making the set of windings on the inner peripheral side close to upright, the bottom outer edge is curved and the bottom is directed downward In the object to be heated having a convex shape, a set of windings are substantially perpendicular to both the bottom outer edge part and the center part surface, so that the entire object to be heated can be efficiently heated.

  Moreover, by setting it as the structure provided with a 3rd layer coil in the outermost periphery of a coil, a magnetic flux can be generated more strongly in the outermost periphery.

  In addition, the above-mentioned electromagnetic induction heating coil and electromagnetic induction heating cooker are illustrations of the present invention, and the configuration thereof can be changed as appropriate without departing from the spirit of the invention.

101, 201, 301, 401, 4011, 501, 601 .. Electromagnetic induction heating coil,
111, 211, 311, 411, 4111, 511, 611,.
112, 212, 312, 412, 4121, 512, 612, ... the second layer coil,
513, 613 .. Third layer coil,
14a, 14b..
15a, 15b .. termination,
16a, 16b ... Leader,
20 .. Electromagnetic induction heating cooker,
21..Main body, 22..Top plate, 23..Housing, 24..Ferrite, 25..Power line,
31 .. Operation part, 32 .. Cable, 33 .. Power switch, 34 .. Output adjustment knob, 35 .. Indicator,
40 ... Heated object OS1, OS2, OS3, OS4 ...

Claims (9)

A first layer coil in which the winding is spirally wound from the outer periphery toward the inner periphery;
A second layer coil in which a winding is wound spirally in the same direction and toward the outer periphery continuously from the innermost periphery of the first layer coil;
A pair of lead wires that are drawn from the outermost circumference of the first layer coil and the second layer coil and supply power to the first layer coil and the second layer coil;
An electromagnetic induction heating coil comprising:   The windings of the first layer coil and the individual windings of the second layer coil form a set of windings that are stacked in a direction perpendicular to the surfaces of the first layer coil and the second layer coil. The electromagnetic induction heating coil according to claim 1, wherein:   The electromagnetic induction heating coil according to claim 2, wherein a gap is provided between the pair of adjacent windings.   The separation distance between the pair of adjacent windings is more than 1.5 times and less than or equal to 1.5 times the diameter of the winding in the inter-axis distance of the windings. Electromagnetic induction heating coil.   5. The electromagnetic induction heating coil according to claim 3, wherein the pair of windings are inclined toward the inner peripheral side.   The electromagnetic induction heating coil according to claim 5, wherein an inclination angle is 60 degrees or more and less than 90 degrees with respect to a surface direction of the first layer coil and the second layer coil. The angle of inclination is configured such that the inner peripheral side is larger than the outer peripheral side of the set of windings,
The angle of inclination of the set of windings on the outermost periphery is 60 degrees or more with respect to the surface direction of the first layer coil and the second layer coil,
6. The electromagnetic induction according to claim 5, wherein an angle of inclination of the pair of windings on the innermost circumference is 90 degrees or less with respect to a surface direction of the first layer coil and the second layer coil. Heating coil. The third layer is wound in the same direction continuously from the outermost periphery of the first layer coil or the second layer coil, and the winding is wound on only the outermost periphery of the first layer coil or the second layer coil. A coil,
8. One of the lead wires is drawn from the outermost periphery of the first layer coil or the second layer coil, and the other lead wire is drawn from the third layer coil. The electromagnetic induction heating coil according to item. The electromagnetic induction heating coil according to any one of claims 1 to 8,
A power supply for supplying power to the electromagnetic induction heating coil;
A top plate provided above the electromagnetic induction heating coil for placing an object to be heated;
An electromagnetic induction heating cooker comprising: