JP2018137247A - Induction heating cooker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a user friendly and highly convenient induction heating cooker capable of increasing the distance between the centers of heating sections and expanding the heating region, without limiting the standard dimensions of the housing section of kitchen provided for housing the body of an induction heating cooker.SOLUTION: An induction heating cooker has a body, a top plate on which a heated object is placed, a support member fixed to the body and supporting the peripheral portion of the top plate, multiple heating sections for induction heating the heated object, multiple electric supply sections for supplying a high frequency current to each heating section, and a control section for controlling the electric supply sections. At least one heating section has a thin heating coil extending over the body at least partially in the horizontal direction between the top plate and the support member, and having a thickness in the vertical direction equal to or less than four times of the skin depth.SELECTED DRAWING: Figure 4

Description

  The present invention relates to an induction heating cooker that heats and cooks foods and the like contained in a heated body by induction heating a heated object such as a metal pan with a high-frequency magnetic field.

  An induction heating cooker such as a so-called IH cooking heater supplies a high-frequency current of approximately 20 kHz to 100 kHz to an induction heating coil wound in a flat shape, and an eddy current is generated in a heated object made of metal by a high-frequency magnetic field generated in the induction heating coil. To generate Joule heat due to eddy current and heat the cooking utensil itself. An IH cooking heater typically has an induction heating coil configured by winding a so-called litz wire or the like in which a plurality of coated conductors are twisted in a planar shape, and a plurality of inductions so that a plurality of ingredients can be cooked at the same time. It has a heating coil (cooking heating port).

  The IH cooking heater is roughly classified into a built-in type and a stationary type from the viewpoint of the installation method in the kitchen. The built-in type IH cooking heater, for example, inserts the cooker body (housing) into a storage part (mounting hole) provided in the system kitchen, and the peripheral part of the top plate protruding from the upper surface of the cooker body is placed around the storage part. It is installed by placing it on the end (worktop).

  The external dimensions of the storage part of the system kitchen are determined by standards to ensure compatibility with other models, and are usually about 560 mm in the left-right direction when the user faces and about 460 mm in the depth direction. . For this reason, the length in the left-right direction of the top plate protruding from the cooker body is generally about 600 mm. That is, when the IH cooking heater has two induction heating coils (cooking heating ports) arranged in a straight line in the left-right direction, the diameter of each induction heating coil is 280 mm or less regardless of the length in the left-right direction of the top plate. It is necessary to design the distance between the centers of each induction heating coil to be 280 mm or more.

  On the other hand, recent IH cooking heaters are desired to increase the diameter of the induction heating coil (cooking heating port) so that larger pots can be used. However, when trying to make the diameter of each induction heating coil as large as possible, for example, when all cooking heating ports are used, the user temporarily puts the seasoning on the top plate and cooks while tasting. In such a case, an empty space (non-cooking space) on the top plate that can be used by the user is limited. That is, since the external dimension of the storage part of the system kitchen is a standard (constant) dimension, in the IH cooking heater having a plurality of large-diameter induction heating coils, a sufficient space on the top plate is ensured. This is not always convenient for the user.

  In particular, when the IH cooking heater has three or more induction heating coils, the designable diameter of the induction heating coil is limited, and ensuring sufficient space for the user is more than that with two induction heating coils. It was difficult. That is, when the user cooks, there is a strong demand for an IH cooking heater having a plurality of large-diameter induction heating coils that secures a sufficient space and improves convenience.

  For example, in the invention described in Patent Document 1, by arranging the interior angles of the triangles connecting the centers of the three induction heating coils to be different from each other, the empty space other than the heating area is effectively used, and the seasoning and the like are induction heated. It is intended to provide an induction heating cooker that can be placed in the vicinity of a coil and is easy to use.

  Further, according to the invention described in Patent Document 2, by arranging the three induction heating coils on a straight line extending in the left-right direction and on the farther side with respect to the user, an empty space in front of each induction heating coil. A built-in induction heating cooker that secures (non-cooking space) and is easy to use and excellent in design has been proposed.

  Furthermore, the invention described in Patent Document 3 includes a plate that covers the upper part of the outer shell, and a flange that extends from the upper part of the storage container to the outer peripheral side and is placed around the cabinet (storage part) of the kitchen device, An induction heating cooker has been proposed in which a part of the heating coil is accommodated between the flange and the plate so that the size of the heating coil can be freely set without being restricted by the size of the cabinet of the kitchen apparatus.

JP 2008-21473 A Japanese Patent No. 5076731 Japanese Patent No. 5313334

  According to the induction heating cooker described in Patent Document 1, the induction heating coil is arranged so that the user can freely use an empty space other than the heating region. However, when placing a pan on the induction heating coil closer to the user, or when moving the pan placed on the induction heating coil closer to the user, the pan placed on the front side In order to avoid this, it is necessary to temporarily lift or move it. In addition, when placing a pan having a diameter larger than that of the induction heating coil, it is not possible to sufficiently secure an empty space that can be freely used by the user, and interfere (contact) with other pans. The intended effect of the invention according to the above cannot be fully exhibited. Moreover, when it interferes with another pan, the pan deviates from the center of the induction heating coil, and the whole pan is not heated uniformly, causing a problem that uneven heating occurs.

  In addition, the induction heating cooker described in Patent Document 2 has a plurality of main body units including an induction heating device, a cooling device, and a control device, and each heating unit is straight on the back side from the center in the back direction of the top plate. By arranging them in parallel, a wide non-cooking space on the front side is ensured. However, it is necessary to provide a space (storage part) for storing a plurality of main body units in the kitchen, and there is a problem that it cannot be adopted in a kitchen having a storage part with a standard size defined by the standard.

  In addition, the induction heating cooker described in Patent Document 3 accommodates a part of the heating coil in the heating coil housing space between the flange and the plate, so that the size of the cabinet of the kitchen apparatus is not restricted. It is possible to improve cooking workability. However, the heating coil described in Patent Document 3 is a general induction heating coil configured by winding a wire having good thermal conductivity such as a copper wire (paragraph [0053]), and a resin that coats the copper wire. In order to supply a necessary high-frequency current, it has a substantial thickness. That is, Patent Document 3 describes that the thickness of the heating coil is designed to be 10 mm or less in order to keep the height between the top plate and the top plate of the kitchen to 20 mm or less (paragraph [0047]). No particular mention is made of the specific configuration of the heating coil itself for realizing this.

  Therefore, the present invention has been made to solve the above-described problems, and is a standard for a kitchen cabinet (storage unit) provided for storing a main body (housing) of an induction heating cooker. An object of the present invention is to provide an induction heating cooker that is easy to use and highly convenient for a user while expanding the center-to-center distance between heating units and the heating region without being restricted by the general dimensions.

  An induction heating cooker according to the present invention includes a main body, a top plate on which a heated object is placed, a support member fixed to the main body and supporting a peripheral edge of the top plate, and the heated object A plurality of heating units for induction heating, a plurality of power supply units for supplying a high-frequency current to each heating unit, and a control unit for controlling the power supply unit, wherein at least one of the heating units includes the top plate and It has a thin heating coil that extends at least partially in the horizontal direction between the support member and the main body, and whose vertical thickness is not more than four times the skin depth.

  According to the present invention, a thin heating coil that extends at least partially in the horizontal direction beyond the main body portion is provided between the top plate and the support member, and the thickness in the vertical direction is designed to be four times or less the skin depth. Thereby, the heating area | region of a heating part can be expanded substantially from a main-body part. Therefore, the thickness of the top plate protruding from the worktop of the kitchen can be suppressed as much as possible, and the user's cooking workability can be improved remarkably. Along with this, even if a plurality of large and small pans are placed on the top plate at the same time, each pan is placed at the center of each heating section (heating area) without interfering (contacting) with each other. Thus, it can be heated uniformly without uneven heating. Furthermore, it is possible to secure a wider vacant space between each heating unit and the operation panel, and to realize high convenience that is convenient for the user.

1 is a perspective view schematically illustrating the entire induction heating cooker according to the present invention. It is a top view which shows the worktop of the kitchen containing the accommodating part in which the induction heating cooking appliance is accommodated. It is a top view of the induction heating cooking appliance accommodated in the storage part of the worktop of a kitchen. It is a top view which shows the induction heating cooking appliance after removing a top plate. It is sectional drawing of the induction heating cooking appliance 1 seen from the VV line | wire of FIG. (A) And (b) is a top view of the heating coil of a center heating part. It is sectional drawing of the center heating part seen from the VII-VII line of FIG. It is a reference perspective view which shows a mode that a frying pan is mounted on the top plate above a center heating part, and a standard pan is mounted above the left side heating part and the right side heating part. It is a reference perspective view which shows a mode that a big pan is mounted on the top plate above a center heating part, and a standard pan is mounted above the left side heating part and the right side heating part. 3 is a perspective view illustrating a schematic configuration of a left side heating unit and a right side heating unit according to Embodiment 1. FIG. (A) And (b) is a block circuit diagram which shows the electric circuit structure of the electric power feeding part for supplying a high frequency current to the left side heating part or the right side heating part. FIG. 6 is an enlarged cross-sectional view of the left side heating unit and its peripheral part in FIG. It is a graph which shows the relationship between the thickness of a heating plate, and the current density J. (A) And (b) is the schematic which shows the heating plate and transformer which concern on the modification of Embodiment 1. FIG. (A) is a perspective view which shows the heating plate of the left side heating part or right side heating part which concerns on another modification, (b) is sectional drawing when cut | disconnecting by the broken-line cross section of (a). FIG. 16 is a cross-sectional view of a heating plate and a transformer according to another modification. FIG. 16 is a cross-sectional view showing a transformer according to yet another modification that is magnetically coupled to the heating plate shown in FIGS. It is a block circuit diagram which shows the electric circuit structure of the electric power feeding part which supplies a high frequency current to the left side heating part or the right side heating part via the transformer of FIG. It is sectional drawing to which the left side heating part containing the thin heating coil which concerns on Embodiment 2, and its peripheral part was expanded, and is an expanded sectional view similar to FIG. 6 is a plan view of a thin heating coil according to Embodiment 2. FIG. It is a schematic sectional drawing of the thin heating coil seen from the XXI-XXI line of FIG. FIG. 21 is a schematic perspective view showing a long laminated conductor constituting the thin heating coil of FIG. 20 and showing a state before being spirally wound around a coil axis (Z axis). FIG. 23 is a cross-sectional view of the thin heating coil shown in FIG. 20 taken along a vertical plane. It is the graph obtained by measuring the emitted-heat amount by winding resistance when driving several thin heating coils from which height differs on the same conditions. It is the graph obtained by measuring the temperature of the upper surface when driving a plurality of thin heating coils having different heights under the same conditions. FIG. 10 is a plan view of a thin heating coil of a modification according to the second embodiment. It is a perspective view similar to FIG. 1 of the induction heating cooking appliance which concerns on Embodiment 3. FIG. It is a top view similar to FIG. 4 of the induction heating cooking appliance of FIG. It is sectional drawing similar to FIG. 5 of the induction heating cooking appliance of FIG. It is a reference perspective view which shows a mode that the standard pan was mounted on the top plate above each heating part.

  Embodiments of an induction heating cooker according to the present invention will be described below with reference to the accompanying drawings. In the description of each embodiment, terms for indicating directions (for example, “up”, “down”, “right”, “left”, etc.) are used as appropriate for easy understanding. These terms are not intended to limit the invention. In the accompanying drawings, the same components are referred to by the same reference numerals.

Embodiment 1 FIG.
The first embodiment of the induction heating cooker according to the present invention will be described in detail below with reference to FIGS. FIG. 1 is a perspective view schematically illustrating the entire induction heating cooker 1 according to the present invention. The induction heating cooker 1 according to the present invention is a so-called built-in type IH cooking heater that is installed in a storage section provided on a worktop of a kitchen, and is roughly configured mainly of sheet metal as shown in FIG. The main body 2, a heat-resistant top plate (hereinafter referred to as “top plate”) 3 that covers substantially the entire upper surface of the main body 2, a plurality of heating units 10, 20 a, 20 b, and cooking A grill 4 is provided. As shown in FIG. 1, the heating units disposed at the center, the left side, and the right side on the top plate 3 as viewed from the user are referred to as a central heating unit 10, a left heating unit 20a, and a right heating unit 20b, respectively.

  The induction heating cooker 1 according to each embodiment has an intake window 5 and a pair of exhaust windows 6 a and 6 b provided on the back side of the top plate 3. Furthermore, although not shown here, the induction heating cooker 1 includes power supply units 30, 40a, and 40b that supply high-frequency currents to the heating units 10, 20a, and 20b, and a control unit 50 that controls them.

  In each of the embodiments described below, an induction heating cooker having a so-called center grille structure in which the cooking grill 4 is disposed substantially at the center of the main body 2 will be described as an example. However, the present invention is not limited to this. The cooking grill 4 is biased to one of the side surfaces (induction heating cooking device having a so-called side grill structure) or the induction heating cooking device not provided with the cooking grill 4 can do.

  In addition, the induction heating cooker 1 according to each embodiment includes a top operation unit (operation panel) 7 used by a user to operate each heating unit 10, 20 a, 20 b and cooking grill 4, and “thermal power ( Display using a front operation part (thermal power adjustment dial) 8a, 8b for adjusting the output power) and a liquid crystal display element for displaying a control state and an operation guide by the operation panel 7 and the thermal power adjustment dials 8a, 8b. Part 9a, 9b. However, the configuration and arrangement positions of the operation panel 7, the heating power adjustment dials 8a and 8b, and the display units 9a and 9b are not limited to those illustrated in the drawings. For example, in an induction heating cooker having a side grill structure, The heating power adjustment dials 8a and 8b may be arranged together on the side opposite to the cooking grill 4. The operation panel 7, the thermal power adjustment dials 8a and 8b, and the display units 9a and 9b are connected to the control unit 50, and the magnitude of the high-frequency current supplied to the heating units 10, 20a, and 20b is the thermal power adjusted by the user. It is controlled by the control unit 50 according to the size of.

FIG. 2 shows a storage unit 101 provided on a worktop 100 of a kitchen, in which the main body 2 of the induction heating cooker 1 according to each embodiment is stored. As described above, the outer dimensions of the storage unit 101 are standardized according to the standard in Japan, and the horizontal dimension W ₀ is about 560 mm and the depth direction D ₀ is about 460 mm. . Therefore, the manufacturer who manufactures the induction heating cooker 1 designs the external dimensions of the induction heating cooker 1 so that the main body 2 of the induction heating cooker 1 is accommodated in the storage portion 101 of the worktop 100.

  FIG. 3 is a plan view of the induction heating cooker 1 in which the main body 2 is housed in the housing 101. In the drawing, in order to clarify the positional relationship of the storage unit 101 of the work top 100 with respect to the top plate 3, the central heating unit 10, the left side heating unit 20a, and the right side heating unit 20b, the position of the storage unit 101 is indicated by a broken line. As will be described in detail later, in the induction heating cooker 1 of the present invention, a part of the left side heating part 20a and the right side heating part 20b extends beyond the main body part 2 in the left-right direction. Although the induction heating cooking appliance 1 shown in FIG. 3 is not limited to this, the dimension W in the left-right direction may be about 750 mm, and the dimension D in the depth direction may be about 510 mm.

  4 is a plan view showing the induction heating cooker 1 after the top plate 3 is removed, and FIG. 5 is a cross-sectional view of the induction heating cooker 1 as seen from the line VV in FIG. 6 (a) and 6 (b) are plan views of the central heating coil 12 of the central heating unit 10, and FIG. 7 is a cross-sectional view of the central heating unit 10 as viewed from the line VII-VII in FIG. .

  The central heating unit 10 shown in FIG. 6 (a) includes central coils 13a and 13b formed by winding a plurality of so-called litz wires, which are a plurality of twisted wires obtained by coating a copper wire with a resin or the like. It has four peripheral coils 14a-14d. This is known by the registered trademark of “Bikkuring Coil” by the present applicant. The central coils 13a and 13b have an inner subcoil 13a and an outer subcoil 13b wound concentrically, and each peripheral coil 14a to 14d has a semicircular arc shape (banana or pepper) along the outer subcoil 13b of the central coil. In the shape). The inner subcoil 13a and the outer subcoil 13b of FIG. 6A may be connected in series, or may be configured to be able to efficiently heat the small pot P by being connected in parallel and driven independently. .

  As shown in FIG. 7, the central heating unit 10 includes a coil base 17 that supports the central coils 13 a and 13 b and the peripheral coils 14 a to 14 d, and a plurality of ferrite cores 18 that extend radially or radially at the bottom of the coil base 17. Have The ferrite core 18 is made of a material having high magnetic permeability, and has a function of increasing the eddy current formed in the pan P by being magnetically coupled to the central coils 13a and 13b and the peripheral coils 14a to 14d. As described above, the central heating unit 10 may be known as the above-mentioned “bikk ring coil”, and a space for accommodating the central heating unit 10 can be sufficiently secured in the center of the main body 2. There is little need to reduce the thickness.

  Further, as shown in FIG. 6 (b), the central heating unit 10 has central coils 15a and 15b and peripheral coils 16a and 16b that are similarly configured by winding a litz wire concentrically in a plurality of turns. May be. The central coil in FIG. 6B may be composed of sub-coils 15a and 15b connected in series, and the peripheral coil may be composed of sub-coils 16a and 16b that are similarly connected in series, or each sub-coil 15a. , 15b, 16a, and 16b may be connected in parallel and individually driven to efficiently heat the pan P having an arbitrary size. In addition, although not shown in figure, the electric power feeding part 30 for supplying a high frequency current to this center heating part 10 can be comprised using the arbitrary inverter circuits widely known to those skilled in the art. Since the central coils 15a and 15b and the peripheral coils 16a and 16b are formed by winding litz wires, it is desirable to cool them using a cooling fan or the like (not shown) as necessary. .

  The central heating unit 10 according to the first embodiment is designed to have a larger diameter than the left heating unit 20a and the right heating unit 20b. The left side heating unit 20a and the right side heating unit 20b have a diameter (for example, 200 mm) sufficient to heat the object P to be heated such as a standard pan, and the central heating unit 10 has a larger pan, frying pan, or the like. It has a diameter (for example, 240 mm) sufficient to heat the article to be heated P. 8 and 9, a large pan or pan P1 is placed on the top plate 3 above the central heating unit 10, and standard pans P2 and P3 are placed above the left heating unit 20a and the right heating unit 20b. It is a reference perspective view which shows a mode that it has mounted.

  FIG. 10 is a perspective view illustrating a schematic configuration of the left side heating unit 20a and the right side heating unit 20b according to the first embodiment. Each of the left heating unit 20a and the right heating unit 20b includes a heating plate 22 and a transformer 25 that form an electrical closed circuit. The heating plate 22 is made of a metal such as copper or iron, and includes an excitation unit 23 formed in a donut shape and a power reception unit 24 that extends substantially in the horizontal direction. On the other hand, the transformer 25 includes a base portion 26 made of a magnetic material, a pair of wall portions 27 extending in a direction perpendicular to the base portion 26, and an opening 28 formed between the pair of wall portions 27. A primary coil is formed by winding a winding 29 having a cross section and having an insulating coating on the base 26. The power receiving unit 24 of the heating plate 22 is inserted into the opening 28 of the transformer 25 (arrow in FIG. 10), and is linked to a high frequency magnetic field generated by the transformer 25 (primary coil) supplied with a high frequency current from the power supply unit 40. (Magnetically coupled as in the secondary coil and supplied with electric power), and by forming a high-frequency loop current in the electrical closed circuit of the heating plate 22, an eddy current is formed at the bottom of the heated body P. This is induction-heated.

  FIG. 11A is a block circuit diagram showing an electric circuit configuration of each of the power feeding units 40a and 40b for supplying a high-frequency current to the left heating unit 20a and the right heating unit 20b. Each of the power supply units 40 a and 40 b is roughly parallel to a converter (for example, a diode bridge) 44 that converts the single-phase AC power source 42 into a DC current, a smoothing capacitor 46 connected to the output terminal of the converter 44, and the smoothing capacitor 46. And an inverter 48 connected thereto. The inverter 48 converts the direct current from the converter 44 into a high-frequency current, and supplies the high-frequency current to the heating plate 22 via the transformer 25 (by the power receiving unit 24 interlinking with the high-frequency magnetic field generated in the transformer 25). . In FIG. 11A, the heating plate 22 is illustrated as an equivalent circuit of an inductance L and a resistance R. The inverter 48 can supply a high-frequency current to the heating plate 22 under an arbitrary driving condition in response to an arbitrary control signal from the control unit 50.

  11 (a) supplies high-frequency current from the inverter 48 to the heating plate 22 via the transformer 25, but as shown in FIG. 11 (b), the heating plate 22 is provided. A portion corresponding to the power receiving unit 24 may be cut to provide a pair of terminals, and a high-frequency current may be supplied directly from the inverter 48 to the terminals. Although not shown in detail, a power feeding unit 30 (not shown) for supplying high-frequency current to the central coils 13a, 13b, 15a, 15b and the peripheral coils 14a-14d, 16a, 16b formed by winding litz wires. May have an electric circuit configuration similar to that shown in FIG. Here, by setting the power supply unit 30 and the power supply unit 40 so that the maximum heating power (for example, about 3000 W) can be supplied, the central heating unit 10, the left heating unit 20a, and the right heating unit 20b Any heating unit can be used with the maximum heating power, cooking time can be shortened, and the user-friendly and convenient induction heating cooker 1 can be realized.

  FIG. 12 is an enlarged cross-sectional view of the left side heating unit 20a and the periphery thereof in FIG. 5, and shows a schematic configuration of an electric circuit for supplying a high frequency current to the heating plate 22. As shown in FIG. As described above, the induction heating cooker 1 according to the first embodiment includes the main body 2 housed in the housing 101 of the worktop 100 of the kitchen, the top plate 3 on which the pan P is placed, and the heating plate. 22, a power supply unit 40 that supplies a high-frequency current to the heating plate 22 via the transformer 25, and a control unit 50 that controls the power supply unit 40. Further, the induction heating cooker 1 protects the frame 62 disposed so as to surround the peripheral edge 61 of the top plate 3 and the work top 100, and an elastic cushioning material (spacer) that prevents entry of foreign matters such as water. 64. Furthermore, the induction heating cooker 1 supports the peripheral edge 61 of the top plate 3 at one end, and supports the other end detachably attached to the main body 2 using fixing means 66 such as bolts and nuts. A member 68 is provided. The support member 68 is made of a metal material. When the main body 2 is attached, the support member 68 supports the weight of the main body 2 (in a suspended state). And is bent near the peripheral edge 61 of the top plate 3 so as to provide a narrow gap Δh (FIG. 12, for example, 2 mm to 10 mm) between the top plate 3 and the worktop 100 of the kitchen. Processed (squeezing or beading).

  When a high-frequency current is supplied to the heating plate 22 configured as described above, the exciting portion 23 and the bottom of the pan P are magnetically coupled, and an eddy current is formed at the bottom of the pan P. P is induction heated. At this time, the high-frequency current flowing through the excitation unit 23 of the heating plate 22 is concentrated on the upper surface of the excitation unit 23 due to the skin effect. The skin effect means that when a high-frequency current flows through the excitation unit 23, the current density is high on the upper surface of the excitation unit 23 and decreases as the distance from the upper surface increases. In general, the current density J of the high-frequency current flowing through the excitation unit 23 is expressed by the following equation with respect to the depth (thickness in the vertical direction from the upper surface) δ.

ここで、ｄは励磁部２３の上側表面からの深さであり、表皮深さ（または浸透深さ）δとは、高周波電流が表面電流Ｊ_０の１／ｅ（約３６．８％）になる深さをいう。具体的には、加熱プレート２２の励磁部２３の電気抵抗をρ、高周波電圧（高周波電流）の周波数をｆ、励磁部２３の透磁率をμ、励磁部２３の導電率をσとすると、表皮深さδは次式で求められる。

Here, d is the depth from the upper surface of the excitation portion 23, the skin depth (or penetration depth) [delta] A, the 1 / e of the high frequency current is the surface current J ₀ (about 36.8%) The depth to become. Specifically, when the electrical resistance of the excitation unit 23 of the heating plate 22 is ρ, the frequency of the high frequency voltage (high frequency current) is f, the permeability of the excitation unit 23 is μ, and the conductivity of the excitation unit 23 is σ, the skin The depth δ is obtained by the following equation.

The heating plate 22 (excitation part 23) is preferably formed of copper, aluminum, or an alloy thereof having a high conductivity σ and relatively inexpensive. For example, when the heating plate 22 is manufactured by punching and bending a copper plate, the relative permeability μr of copper is about 1, the resistivity ρ is 1.72 × 10 ⁻⁸ Ω · m, and the conductivity σ is about 58. .1 × 10 ⁶ S / m, the skin depth δ is 0.467 mm when the frequency f of the high-frequency current is 20 kHz, 0.418 mm when the frequency f is 25 kHz, and the frequency f is 100 kHz. In this case, it becomes 0.209 mm.

FIG. 13 is a graph obtained by plotting the thickness d of the heating plate 22 (excitation unit 23) on the horizontal axis, that is, the distance from the upper surface of the excitation unit 23, and the current density J on the vertical axis. As is apparent from FIG. 13, the current flowing through the excitation unit 23 exponentially attenuates with the depth d in the vertical direction (thickness direction) from the upper surface of the excitation unit 23 as a parameter, and the upper surface of the excitation unit 23 From 1 to e (about 36.8%) of the surface current flows below the skin depth δ (d = δ), and below the surface depth δ twice (d = 2δ) A current of 1 / e ² (about 13.5%) flows, and a current of 1 / e ³ (about 5.0%) of the surface current flows below the surface depth δ of 3 times (d = 3δ). That is, the magnitude of the high-frequency current flowing through the excitation portion 23 corresponds to a value obtained by integrating the current density J shown in FIG. 13 by the skin depth, and even if the thickness of the excitation portion 23 is four times or more of the skin depth δ. The effect does not substantially increase the high frequency current.

  The frequency f of the high frequency current applied to the induction heating cooker is limited to a range of 20 kHz to 100 kHz according to Japanese law. When the heating plate 22 is made of copper, for example, the frequency f of the high frequency current is 20 kHz. In this case, a sufficient amount of high-frequency current can be passed through the heating plate 22 even when the skin depth is δ (= 0.467 mm) or less. That is, when the heating plate 22 is made of copper, it can be made 1.868 mm or less without substantially limiting the amount of high-frequency current. However, the thickness of the heating plate 22 may be designed to be about 2 mm or more in order to ensure the mechanical strength. As described above, the heating plate 22 can be designed to be extremely thin as compared with an induction heating coil formed using a litz wire or the like, and is also referred to as a “thin heating coil” in the present application.

  As described above, the heating plate 22 constituting the left heating unit 20a and the right heating unit 20b according to Embodiment 1 partially extends beyond the main body unit 2 in the horizontal direction (FIG. 12). ), Which can be made very thin (with a thickness less than 4 times the skin depth δ) compared to a conventional heating coil constructed by winding a so-called litz wire, and the top plate 3 and kitchen worktop Similarly, the gap Δh with respect to 100 can be designed to be very narrow. That is, according to the present invention, the thickness of the top plate 3 protruding from the work top 100 of the kitchen can be suppressed as much as possible, and the user's cooking workability can be remarkably improved. The power receiving unit 24 of the heating plate 22 and the transformer 25 including the winding 29 are housed in the main body 2 together with the power feeding unit 40.

  Although not shown in detail, the left side heating unit 20a and the right side heating unit 20b, like the central heating unit 10, heat the coil base 17 for supporting the heating plate 22 and the ferrite core 18 composed of a material having high magnetic permeability. You may arrange | position below the excitation part 23 of the plate 22. FIG. Further, a magnetic shield member (not shown) made of a nonmagnetic material such as aluminum may be disposed between the ferrite core 18 and the support member 68. Therefore, according to the induction heating cooker 1 according to the first embodiment, for example, the coil base 17 and the magnetic shield member depend on the presence and / or thickness of the coil base 17 (including the ferrite core 18) and the magnetic shield member. When the thickness is 2 mm, the height Δh (FIG. 12) between the work top 100 and the top plate 3 of the kitchen can be designed to be extremely thin (for example, 6 mm).

  In addition, the heating plate 22 according to the first embodiment is easy to manufacture and does not include an insulating coating having a high thermal conductivity like litz wire, so that the temperature rise is suppressed and even if the temperature becomes high, it looks like litz wire. In addition, since a short circuit between core wires (layer short) does not occur, it can be manufactured with high reliability and at low cost. That is, since the heating plate 22 does not have an insulating film like a litz wire, it does not need to be cooled in order to prevent a short circuit even when the heating plate 22 becomes hot, and it is disposed close to or in close contact with the top plate 3. Can do. Rather, by arranging the heating plate 22 close to or in close proximity to the top plate 3, the radiant heat from the heating plate 22 that has become high temperature due to the Joule heat of the high-frequency current can be supplied to the pan P through the top plate 3. And high energy conversion efficiency can be realized.

  In addition, although the central heating part 10 which concerns on Embodiment 1 was demonstrated as what is comprised by winding what is called a litz wire, as demonstrated above with reference to Fig.6 (a) and (b). Alternatively, the heating plate 22 similar to the left heating unit 20a and the right heating unit 20b may be used.

  Furthermore, the further effect of the present invention obtained by designing the heating plate 22 to be thin so that a part of the excitation part 23 of the heating plate 22 extends beyond the main body part 2 in the horizontal direction will be described. Returning to FIG. 4 again, the central heating unit 10 has a central heating coil 12 having a diameter of 240 mm and a maximum heating area diameter of 300 mm, which is suitable for cooking the large pan P1, and the left heating unit 20a and The right side heating unit 20b has heating plates 22a and 22b having a diameter of 200 mm and a maximum heating area diameter of 240 mm, and is suitable for cooking standard pans P2 and P3. The center heating unit 10, the left side heating unit 20a, and the right side heating unit 20b are arranged so that an obtuse isosceles triangle having the centers O1, O2, and O3 as apexes is formed. At this time, as described above, since a part of the excitation part 23 is designed to extend beyond the main body part 2 in the horizontal direction, the dimension W in the left-right direction of the induction heating cooker 1 is about 750 mm, and the frame 62 occupies it. Even if a region to be performed (for example, 15 mm on each side) is excluded, an effective dimension of a cooking region of about 720 mm can be ensured. More specifically, the distances L1 and L2 between the centers O1 and O2 and between the centers O1 and O3 can be designed to be 240 mm, and the distance L0 between the centers O1 and O3 can be designed to be 480 mm. At this time, a portion corresponding to a maximum length of 80 mm (heating region) among the left portion (left heating region) of the heating plate 22a of the left heating unit 20a and the right portion (right heating region) of the heating plate 22b of the right heating unit 20b. Can be enlarged from the dimension of the main body 2 in the left-right direction. Therefore, according to the present invention, as shown in FIGS. 8 and 9, even if the large pan P1 and the standard pans P2 and P3 are placed on the top plate 3 at the same time, the pan P1 does not interfere (contact) with each other. , P2, and P3 are arranged (at appropriate positions) at the centers O1, O2, and O3 of the central heating unit 10, the left heating unit 20a, and the right heating unit 20b, and can be heated uniformly without uneven heating.

  In addition, since the central heating coil 12 is disposed on the near side of the straight line connecting the centers O2 and O3 of the left heating unit 20a and the right heating unit 20b (close to the operation panel 7), the central heating coil 12 is on the left and right sides. Thus, an empty space can be formed on the top plate 3. That is, an empty space can be formed on the top plate 3 between the left heating unit 20 a and the right heating unit 20 b and the operation panel 7. Therefore, according to a general conventional induction heating cooker, there is an empty space on the top plate 3 between the left heating unit 20a and the right heating unit 20b and between the central heating unit 10 and the operation panel 7. As formed, according to the induction heating cooker according to the first embodiment, in the substantially larger empty space between the left side heating unit 20a and the right side heating unit 20b and the operation panel 7, the user can use seasonings and the like. Can be temporarily placed on the top plate 3 on the front side of the user and cooked while tasting, and a very convenient and high convenience can be realized.

  Next, further modifications regarding the heating plate 22 and the transformer 25 constituting the left heating unit 20a and the right heating unit 20b according to the first embodiment will be described below. 14A and 14B are schematic views showing a transformer 25 (a part of the heating plate 22) according to a modification. The transformer 25 of FIG. 10 according to the first embodiment is configured by winding a winding 29 having an insulating coating on its base portion 26. As shown in FIGS. 14 (a) and 14 (b), a pair of walls is provided. The winding 29 may be wound around both or one of the portions 27. Further, as shown in FIG. 14B, the transformer 25 similarly has a high frequency magnetic field generated by a winding (primary coil) 29 by arranging a lid 31 made of a magnetic material so as to cover the opening 28 of the transformer 25. You may comprise so that it may strengthen.

  FIG. 15A is a perspective view showing the heating plate 22 of the left side heating unit 20a and the right side heating unit 20b according to another modification, and FIG. 15B is a cross-sectional view taken along the broken line in FIG. It is sectional drawing of the heating plate 22 when it did. The left side heating unit 20a and the right side heating unit 20b according to this modification include two heating plates 22a and 22b and a transformer 25, respectively. The diameter of the doughnut-shaped excitation part 23a of the heating plate 22a is smaller than that of the doughnut-shaped excitation part 23b of the heating plate 22b, and the power receiving parts 24a and 24b of the heating plates 22a and 22b extend in parallel to each other in the vertical direction. FIG. 16 is a cross-sectional view of the heating plates 22a and 22b and the transformer 25 according to this modification. A transformer 25 shown in FIG. 16 has a base portion 26, three wall portions 27 extending in a direction perpendicular to the base portion 26, and an E-shaped cross section including two opening portions 28a and 28b. A primary coil is formed by winding a winding 29 with an insulating coating around the arranged wall 27. A winding (primary coil) 29 of the transformer 25 is connected to a single power supply unit 40, is supplied with a high frequency current to form a high frequency magnetic field, and the high frequency magnetic field is a heating plate 22a that functions as a secondary coil. The object to be heated P is inductively heated by forming a high-frequency loop current in an electrically closed circuit of the heating plates 22a and 22b in linkage with the power receiving units 24a and 24b of 22b.

  FIG. 17 is a cross-sectional view showing a transformer 25 according to still another modification, which is magnetically coupled to the heating plates 22a and 22b shown in FIGS. 15 (a) and 15 (b). The transformer 25 according to this modification has the same E-shaped cross section as the transformer 25 of FIG. 16, but two windings (primary coils) 29a and 29b connected to two mutually independent power feeding portions 40a and 40b. Have The two windings 29a and 29b are wound around wall portions 27a and 27b arranged on both sides in the drawing. FIG. 18 is a block circuit diagram showing an electric circuit configuration of a power feeding unit 40 for supplying a high-frequency current to the left heating unit 20a and the right heating unit 20b according to this modification. The power feeding unit 40 shown in FIG. 18 is the same as the power feeding unit 40 shown in FIGS. 11 (a) and 11 (b), but two power supplies for supplying high-frequency current to the two windings (primary coils) 29a and 29b. Inverters 48a and 48b are provided. In FIG. 18, the heating plates 22a and 22b are similarly illustrated as equivalent circuits of inductances La and Lb and resistors Ra and Rb. The inverters 48a and 48b can receive an arbitrary control signal from the control unit 50 and supply a high-frequency current to the heating plates 22a and 22b under an arbitrary driving condition, so that one of the heating plates 22a and 22b is supplied from the other. High power (thermal power) can be output. That is, the left side heating unit 20a and the right side heating unit 20b according to this modification drive only the inner heating plate 22a to efficiently heat the small pot P, or drive only the outer heating plate 22b, The pot skin of P can be heated more strongly, and the driving conditions of the heating plates 22a and 22b can be adjusted according to the size of the pot P and the cooking method. Here, by setting the power supply unit 30 and the power supply unit 40 so that the maximum heating power (for example, about 3000 W) can be supplied, the central heating unit 10, the left heating unit 20a, and the right heating unit 20b Any heating unit can be used with the maximum heating power, cooking time can be shortened, and the user-friendly and convenient induction heating cooker 1 can be realized.

  In addition, although the induction heating cooking appliance 1 which concerns on the said Embodiment 1 has the heating part of three (3 ports), the center heating part 10, the left side heating part 20a, and the right side heating part 20b, this invention Can be equally applied to induction heating cookers having two (two ports) or four (four ports) or more heating units.

  Further, although the heating plate 22 according to the first embodiment and each modification has been described and illustrated as having a circular planar shape, the heating plate 22 is not limited to this and has a rectangular (square or rectangular) and elliptical planar shape. You may have (not shown). In particular, the rectangular planar shape of the heating plate 22 is suitably used when the object P to be heated is a fry pan for fried eggs or an iron plate for fried noodles.

Embodiment 2. FIG.
The second embodiment of the induction heating cooker according to the present invention will be described in detail below with reference to FIGS. Instead of the heating plates 22 (thin heating coils) of the heating units 20a and 20b according to the first embodiment, the heating units 20a and 20b according to the second embodiment are roughly formed of a long laminated conductor in a spiral shape. Since it has the same configuration as the induction heating cooker 1 of Embodiment 1 except that it has the thin heating coil 52 formed by winding, the description of the overlapping contents will be omitted.

  FIG. 19 is an enlarged cross-sectional view similar to FIG. 12, in which the left heating unit 20a and its peripheral part are enlarged. As will be described in detail later, the heating unit 20 is a rectangular induction heating coil (thin heating coil 52) formed by winding a laminated conductor 54 around a coil shaft 55, a supporting coil base 17, and the like. A plurality of ferrite cores 18 extending radially or radially are provided at the bottom of the coil base 17. FIG. 20 is a plan view of the thin heating coil 52 according to the second embodiment. The thin heating coil 52 has a diameter of about 200 mm, for example, and can uniformly inductively heat a pan P having a diameter of about 240 mm. FIG. 21 is a schematic cross-sectional view of the thin heating coil 52 viewed from the XXI-XXI line of FIG. 20, and this thin heating coil 52 is configured by winding the laminated conductor 54 around the coil shaft 55 for eight turns. It is a flat rectangular induction heating coil.

  More specifically, the thin heating coil 52 according to the second embodiment is configured by winding a long laminated conductor 54 shown in FIG. 22 around a coil axis (Z axis) 55 in a spiral shape. And has terminals 56 and 57 at both ends thereof. 23 is a cross-sectional view of the thin heating coil 52 shown in FIG. 20 taken along a vertical plane (XZ plane in FIG. 22). A laminated conductor 54 shown in FIG. 23 is made of a relatively inexpensive metal having high electrical conductivity such as copper, aluminum, or an alloy thereof, and a plurality of conductors extending in the longitudinal direction of the laminated conductor 54 are formed. The conductive layer 58 is laminated, and an electrically insulating layer 59 formed between the adjacent conductive layers 58. That is, the conductive layers 58 are insulated from each other by the insulating layer 59, and preferably surrounded by the insulating layer 59, so that they are not exposed except at both the winding start and end terminals 56 and 57 (FIG. 20) of the thin heating coil 52. It is configured.

  22 has a width r in the direction perpendicular to the coil axis (X direction) of 1.96 mm and a height d in the direction parallel to the coil axis (Z direction) of 1.40 mm, for example. May be. Each conductive layer 58 has, for example, a width in the X direction of 0.1 mm and a height in the Z direction of 1.36 mm, and each insulating layer 59 has a width in the X direction and a height in the Z direction of 0.1 mm. It may be 02 mm and surround the 14 conductive layers 58. In the second embodiment, the width in the X direction, the height d in the Z direction, and the number of turns of the elongated laminated conductor 54 and each conductive layer 58 and each insulating layer 59 constituting the long conductive conductor 54 are the above numerical values. It is not limited to.

  In the thin heating coil 52 according to the second embodiment, unlike the first embodiment, an insulating layer 59 is laminated between adjacent conductive layers 58 to prevent a short circuit (layer short) between the conductive layers 58. Therefore, it is preferable to cool each insulating layer 59 with cooling air. On the other hand, in this thin heating coil 52, as in the first embodiment, due to the skin effect, current concentrates on the upper surface of the thin heating coil 52 (laminated conductor 54 in FIG. 23) and more heat is generated. Therefore, the thin heating coil 52 according to the second embodiment is configured so that the width r in the X direction of the laminated conductor 54 shown in FIG. 23 is larger than the height d in the Z direction (r> d). The heat generated in the vicinity of the upper surface of the thin film is rapidly transferred to the lower surface, and the lower surface of the thin heating coil 52 is cooled to improve the cooling efficiency of the thin heating coil 52. Moreover, it is preferable to provide a gap between the upper surface of the thin heating coil 52 and the top plate 3 to form an air passage through which cooling air flows.

  The laminated conductor 54 may be formed by bonding the conductive layers 58 and the electrical insulating layer 59 as described above, but a thin film made of a conductive material (corresponding to the conductive layer 58) and an insulating material. A thin film made of (corresponding to the insulating layer 59) may be alternately laminated by metal vapor deposition or sputtering.

  In addition, since the conventional induction heating coil includes a lot of insulating coatings in the litz wire that constitutes this, the thermal conductivity in the height direction is not good, and it is difficult to guide the cooling air from the upper surface on the shortest path, A sufficient cooling effect could not be obtained. However, even if the thin heating coil 52 according to the present invention is arranged close to the top plate 3, by making the width W in the X direction of the entire laminated conductor 54 larger than the height d in the Z direction, The entire thin heating coil 52 can be efficiently cooled.

  As described above with reference to FIG. 13, the current flowing through the thin heating coil 52 according to the second embodiment has a depth d in the vertical direction (thickness direction) from the upper surface of the laminated conductor 54 as a parameter due to the skin effect. Decay exponentially. FIG. 24 shows the amount of heat generated by the winding resistance of the thin heating coil 52 (Joule heat or copper loss) when a plurality of thin heating coils 52 with different heights d of the conductive layer 58 are driven under the same conditions. It is the graph obtained. As is apparent from FIG. 24, as the height d of the thin heating coil 52 (conductive layer 58) is increased, the amount of heat generated in the thin heating coil 52 is reduced, and the height d of the conductive layer 58 is equal to the skin depth δ. Since the current density of the high-frequency current is extremely small, the amount of heat generated by the thin heating coil 52 becomes almost constant. That is, in order to maintain the heat generation amount from the thin heating coil 52 below a certain value, it is sufficient to set the height d of the conductive layer 58 to 4 times or less of the skin depth δ. Increasing the size further increases the disadvantage that the cost and weight required for the constituent material of the thin heating coil 52 are increased.

  FIG. 25 is a graph obtained by manufacturing a plurality of thin heating coils 52 having different heights d in the Z-axis direction of the laminated conductor 54 and measuring the temperature of the upper surface thereof. As in the graph of FIG. 24, as the height d of the conductive layer 58 is increased, the amount of heat generated by the thin heating coil 52 is reduced. However, the conductive layer 58 is cooled by applying cooling air from its lower surface. When the height d of the conductive layer 58 exceeds three times the skin depth δ, the cooling effect on the upper surface of the thin heating coil 52 decreases. The temperature will rise. That is, as apparent from FIG. 25, the temperature of the upper surface of the thin heating coil 52 has a minimum point when the height d of the conductive layer 58 is approximately three times the skin depth δ. In order to reduce the material of the thin heating coil 52 and to realize an inexpensive, lightweight and thin thin heating coil 52, the height d of the conductive layer 58 is set to the skin depth. It is desirable to design at approximately 3 times or less of δ.

  FIG. 26 is a plan view of a thin heating coil 52 of a modification according to the second embodiment. A thin heating coil 52 according to this modification has an inner coil 70 and an outer coil 72 that are formed by winding a laminated conductor 54 around a coil axis (Z axis) 55 in a spiral shape. There is a gap between them. In this gap, a pair of temperature sensors 74 such as a thermistor and an infrared sensor connected to the control unit 50 may be provided, and the control unit 50 may be configured to prevent overheating of the pan P.

  As described above, since the thin heating coil 52 constituting the heating parts 20a and 20b according to the second embodiment partially extends beyond the main body part 2 in the horizontal direction (FIG. 19), Like the heating plate 22 of the form 1, it can be made very thin (thickness of 4 times or less of the skin depth δ, for example, thickness of about 2 mm or less when the frequency is 20 kHz), and the top plate 3 and the kitchen worktop. The gap Δh with respect to 100 can also be designed to be narrow. That is, according to the second embodiment, the thickness of the top plate 3 protruding from the worktop 100 of the kitchen can be made as small as possible, and the user's cooking workability can be greatly improved. Further, as in the first embodiment, the thin heating coil 52 according to the second embodiment, as shown in FIGS. 8 and 9, even when the large pan P1 and the standard pans P2 and P3 are simultaneously placed on the top plate 3, The pans P1, P2, and P3 are placed at the centers O1, O2, and O3 of the central heating coil 10, the left side heating unit 20a, and the right side heating unit 20b (in appropriate positions) without interfering (contacting) with each other, and heated. It can be heated evenly. Furthermore, a wide empty space can be ensured between each heating unit 10, 20a, 20b and the operation panel 7, and high convenience that is convenient for the user can be realized.

Embodiment 3 FIG.
A third embodiment of the induction heating cooker according to the present invention will be described below in detail with reference to FIGS. The heating units 10, 20a, 20b according to the first embodiment are arranged such that the centers O1, O2, O3 form an obtuse isosceles triangle, whereas the heating units 10, 20a, 20b according to the third embodiment are arranged. Since 20a and 20b have the same configuration as the induction heating cooker 1 of Embodiment 1 except that the centers O1, O2 and O3 are arranged so as to form a substantially straight line, the overlapping contents Description of is omitted.

  27 is a perspective view similar to FIG. 1 of the induction heating cooker 1 according to Embodiment 3, FIG. 28 is a plan view similar to FIG. 4, and FIG. 29 is similar to FIG. It is sectional drawing. As is apparent from FIGS. 27 and 28, the central heating coil 12 of the central heating unit 10 according to the third embodiment, the heating plate 22a of the left heating unit 20a, and the heating plate 22b of the right heating unit 20b are The centers O1, O2, and O3 are configured to be substantially aligned on a straight line. Further, the heating plates 22a and 22b of the left heating unit 20a and the right heating unit 20b according to the third embodiment are the thin heating coils (the heating plate 22 or the rectangular wire induction described above in the first or second embodiment). It has a heating coil 52). Further, the central heating unit 10 may similarly have the thin heating coil 52 according to the above embodiment in addition to the conventional induction heating coil using the litz wire.

As an example, the storage unit 101 of the kitchen worktop 100 has standard dimensions (FIG. 2: W ₀ × D ₀ , 560 mm × 460 mm), while the induction heating cooker 1 is about 750 m × about 510 mm (FIG. 3: The width of the effective heating area on the top plate is 720 mm at the maximum when the width of the frame 62 arranged around the top plate 3 is 15 mm. When each heating part 10, 20a, 20b has a maximum heating area diameter of 240 mm (dimensions suitable for heating the standard pan P), according to the present invention, a part of the thin heating coil 52 is horizontally aligned with the body part 2. By designing so as to extend beyond the range, the centers O1, O2, and O3 of the heating units 10, 20a, and 20b can be arranged in a substantially straight line. Further, by reducing the left and right occupied width of the frame 62, for example, 5 mm, the distance between the maximum heating areas of the adjacent heating units 10, 20a, 20b can be 10 mm. Further, even when the left and right occupied widths of the frame 62 are each 15 mm, the maximum heating area diameter of 20 a and 20 b among the three heating parts is set to, for example, 220 mm, so that the three heating parts arranged in a substantially straight line are arranged. 20 mm can be secured.

  FIG. 30 is a reference perspective view showing a state where the standard pans P1, P2, P3 are placed on the top plate 3 above the heating units 10, 20a, 20b. As described above, according to the present invention, even if the standard pans P1, P2, and P3 are placed on a substantially straight line and on the top plate 3 at the same time, the pans P1, P1 and P3 do not interfere with each other. P2 and P3 are arranged at the centers O1, O2 and O3 (at appropriate positions) of the respective heating units 10, 20a and 20b, and can be heated uniformly without uneven heating. In addition, according to the third embodiment, a substantially wider empty space can be secured between each heating unit 10, 20a, 20b and the operation panel 7, so that it is convenient for the user and is highly convenient. The cooking device 1 can be realized.

DESCRIPTION OF SYMBOLS 1 ... Induction cooking device, 2 ... Main-body part, 3 ... Top plate, 4 ... Cooking grill, 5 ... Intake window, 6 ... Exhaust window, 7 ... Upper surface operation part (operation panel), 8 ... Front operation part (thermal power) Adjustment dial), 9 ... display unit, 10 ... center heating unit, 12 ... center heating coil, 13,15 ... center coil, 14,16 ... peripheral coil, 17 ... coil base, 18 ... ferrite core, 20a ... left side heating unit 20b ... right side heating part, 22 ... heating plate, 23 ... excitation part, 24 ... power receiving part, 25 ... transformer, 26 ... base part, 27 ... wall part, 28 ... opening part, 29 ... winding, 30, 40 ... power supply , 42 ... single phase AC power supply, 44 ... converter, 46 ... smoothing capacitor, 48 ... inverter, 50 ... control part, 52 ... thin heating coil, 54 ... laminated conductor, 55 ... coil shaft, 56, 57 ... terminal 58 ... conductive layer, 59 ... absolute 61, peripheral edge of the top plate, 62, frame, 64, elastic cushioning material (spacer), 66, fixing means, 68, support member, 70, inner coil, 72, outer coil, 74, temperature sensor, 100, etc. Worktop of kitchen, 101 ... storage section, P ... body to be heated (pan).

Claims (6)

An induction heating cooker, at least part of which is installed on the worktop of the kitchen,
The main body,
A top plate on which the object to be heated is placed;
A support member fixed to the main body and supporting a peripheral edge of the top plate;
A plurality of heating units for induction heating the object to be heated;
A plurality of power feeding sections for supplying a high-frequency current to each heating section;
A control unit for controlling the power feeding unit,
The top plate is partially arranged on the worktop at the time of installation,
At least one of the heating portions extends at least partially between the top plate and the support member in the horizontal direction beyond the main body portion, and at least a part of the heating portion is disposed between the top plate and the worktop when installed. An induction heating cooker having a thin heating coil disposed in The at least one heating unit has a plurality of thin heating coils made of a metal plate forming an electrical closed circuit,
The induction heating cooker according to claim 1, wherein the power feeding unit supplies a high-frequency current independently to each of the thin heating coils.   The induction heating cooker according to claim 2, wherein the metal plate has a rectangular, circular, or elliptical outer shape.   The heating unit includes at least a central heating unit, a left side heating unit, and a right side heating unit, and the center of the central heating unit is closer to the operation unit than the centers of the left side heating unit and the right side heating unit, and the central heating unit The induction heating cooker according to any one of claims 1 to 3, wherein a center of the left side heating unit and the right side heating unit is arranged at an apex of an obtuse triangle.   The heating unit includes at least a center heating unit, a left side heating unit, and a right side heating unit, and the centers of the center heating unit, the left side heating unit, and the right side heating unit are arranged substantially on the same straight line. The induction heating cooker according to any one of claims 1 to 3, wherein the induction heating cooker is configured as described above.   The induction heating cooker according to claim 4 or 5, wherein the central heating unit has a larger diameter than the left heating unit and the right heating unit.

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