JP2022060197A - Induction heating cooker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve convenience.

SOLUTION: An induction heating cooker (1) comprises: a heating plate (10) that has a plurality of heat generation parts (12a, 12b) subjected to induction heating and a heat transfer part (11) for conducting heat generated at the plurality of heat generation parts; a top plate (22) that mounts the heating plate; a plurality of heating coils (23a, 23b) arranged below the top plate and arranged in a region where the plurality of heat generation parts are projected when seen from a thickness direction (a Z direction) of the heating plate, and that performs induction heating of the plurality of heat generation parts, respectively; a plurality of inverters (42a, 42b) that supply a high-frequency current to each of the plurality of heating coils; and a controller (41) that controls an output of each of the plurality of inverters.

SELECTED DRAWING: Figure 2

COPYRIGHT: (C)2022,JPO&INPIT

Description

The present invention relates to an induction heating cooker.

As an induction heating cooker, for example, the induction heating cooker described in Patent Document 1 is known. In the induction heating cooker described in Patent Document 1, a plurality of heating coils are provided below one heating plate, and the power of the plurality of heating coils is individually varied.

Japanese Unexamined Patent Publication No. 5-242959

However, in Patent Document 1, there is still room for improvement from the viewpoint of improving convenience.

Therefore, an object of the present invention is to provide an induction heating cooker capable of improving convenience in solving the above-mentioned problems.

In order to achieve the above object, the induction heating cooker according to one aspect of the present invention is
A heating plate having a plurality of heat generating parts to be induced and heated, and a heat transfer part for conducting heat generated by the plurality of heat generating parts.
The top plate on which the heating plate is placed and the
With a plurality of heating coils arranged below the top plate, arranged in a region where the plurality of heat generating portions are projected when viewed from the thickness direction of the heating plate, and inducing and heating the plurality of heat generating portions, respectively. ,
A plurality of inverters that supply high-frequency current to each of the plurality of heating coils,
A control unit that controls the output of each of the plurality of inverters,
To prepare for.

According to the induction heating cooker according to the present invention, convenience can be improved.

FIG. 1 is a perspective view of an example of an induction heating cooker according to an embodiment of the present invention. FIG. 2 is an exploded perspective view of the induction heating cooker of FIG. FIG. 3 is a bottom view of an example of a heating plate. FIG. 4 is a perspective view of an example of the main body. FIG. 5A is a cross-sectional view of the induction heating cooker of FIG. 1 cut along the line BB. FIG. 5B is an enlarged partially enlarged cross-sectional view of the Z1 portion of the induction heating cooker of FIG. 5A. FIG. 6 is a perspective view of an example of an induction heating cooker according to an embodiment of the present invention when viewed from below. FIG. 7 is an exemplary control block diagram. FIG. 8 is a circuit diagram of a part of an exemplary control circuit of the induction cooking device 1 according to the embodiment of the present invention. FIG. 9 is a schematic configuration diagram showing an exemplary internal configuration of the main body. FIG. 10 is a schematic partial configuration diagram showing an example of the configuration inside the main body around the cooling fan arranged on one end side of the main body. FIG. 11 is another schematic partial configuration diagram showing an example of the configuration inside the main body around the cooling fan arranged on one end side of the main body. FIG. 12A is a diagram showing an example of heating control of the induction heating cooker 1 according to the embodiment of the present invention. FIG. 12B is a diagram showing another example of heating control of the induction cooking device 1 according to the embodiment of the present invention. FIG. 13 is a diagram showing an example of detailed heating control of the induction cooking device 1 according to the embodiment of the present invention. FIG. 14 is a graph showing an example of experimental results when a heating experiment was performed in the induction heating cooker according to the embodiment of the present invention. FIG. 15 is a schematic configuration diagram of an example of a state in which a frame is attached to the induction heating cooker according to the embodiment of the present invention.

(Findings underlying this disclosure)
As an induction heating cooker, there is known one in which a heating plate for heating a cooked food is induced and heated by a plurality of heating coils.

In such an induction heating cooker, the entire bottom surface of the heating plate is induced and heated by a plurality of heating coils. Therefore, regardless of which of the plurality of heating coils is used for induction heating the heating plate, the entire bottom surface of the heating plate is heated.

For example, consider a case where a heating plate is divided into a plurality of heating regions for heating a plurality of cooked foods and heated. In this case, even if the plurality of heating coils heat the plurality of heating regions at different temperatures, it is difficult to realize the heating temperature set by the user or the like in each of the plurality of heating regions.

Therefore, in such an induction heating cooker, it is not possible to heat the cooked food at a desired heating temperature in each of the plurality of heating regions on the heating plate, which is not convenient for the user.

Therefore, the present inventors have conducted diligent studies in order to realize the set heating temperature in each of the plurality of heating regions on the heating plate. The present inventors have configured an induction heating cooker that induces and heats a heating plate having a plurality of heat generating parts to be induced and heated and a heat transfer part for conducting heat generated by the plurality of heat generating parts by means of a plurality of heating coils. And led to the following invention.

The induction heating cooker according to the first aspect of the present invention is
A heating plate having a plurality of heat generating parts to be induced and heated, and a heat transfer part for conducting heat generated by the plurality of heat generating parts.
The top plate on which the heating plate is placed and the
With a plurality of heating coils arranged below the top plate, arranged in a region where the plurality of heat generating portions are projected when viewed from the thickness direction of the heating plate, and inducing and heating the plurality of heat generating portions, respectively. ,
A plurality of inverters that supply high-frequency current to each of the plurality of heating coils,
A control unit that controls the output of each of the plurality of inverters,
To prepare for.

In the induction heating cooker of the second aspect of the present invention, the plurality of heat generating portions may be formed of a metal material having a higher electric resistance value than the metal material forming the heat transfer portion.

In the induction heating cooker of the third aspect of the present invention, the heating plate has a shape symmetrical with respect to the center line of the heating plate extending in the width direction.
The plurality of heat generating portions may be provided symmetrically with respect to the center line of the heating plate.

In the induction heating cooker of the fourth aspect of the present invention, the heating plate has a positioning portion that protrudes from the lower surface of the heating plate toward the top plate side and is located at the outer edge of the top plate. May be good.

In the induction heating cooker according to the fifth aspect of the present invention, the heating plate projects from the lower surface of the heating plate toward the top plate side along the length direction of the heating plate and is the outer edge of the top plate. It may have a rib located at.

In the induction heating cooker of the sixth aspect of the present invention, the lower end of the rib may be located below the upper surface of the top plate and above the lower surface of the top plate.

In the induction heating cooker of the seventh aspect of the present invention, the heating plate may have legs extending from the lower surface of the heating plate to the top plate only on the outside of the plurality of heat generating portions.

In the induction heating cooker of the eighth aspect of the present invention, the heating plate can cook over a plurality of heating regions heated by the plurality of heat generating portions, and partitions the plurality of heating regions. It may have a partition.

In the induction heating cooker of the ninth aspect of the present invention, the partition portion is provided on the upper surface of the heating plate along the center line extending in the width direction of the heating plate when viewed from the thickness direction of the heating plate. It may be a concave portion.

The induction heating cooker according to the tenth aspect of the present invention further includes a frame arranged on the outer edge of the heating plate.
The frame may have frame legs that extend below the top plate and come into contact with the outer edge of the body on which the top plate is placed.

In the induction heating cooker of the eleventh aspect of the present invention, the rib may be located inside the outer surface of the heating plate.

Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. Further, in each figure, each element is exaggerated for the sake of easy explanation.

(Embodiment)
[overall structure]
An example of an induction heating cooker according to an embodiment of the present invention will be described. FIG. 1 is a perspective view of an example of an induction heating cooker 1 according to an embodiment of the present invention. FIG. 2 is an exploded perspective view of the induction heating cooker 1 of FIG. FIG. 3 is a perspective view of an example of the main body 20. In the figure, the X, Y, and Z directions mean the width direction, the length direction, and the thickness direction of the induction heating cooker 1, respectively.

As shown in FIGS. 1 to 3, the induction heating cooker 1 includes a heating plate 10 and a main body 20 on which the heating plate 10 is placed.

[Heating plate]
The heating plate 10 is a plate on which the cooked food is placed on the upper surface and heated. As shown in FIG. 1, the heating plate 10 is a thin plate-shaped flat plate. The heating plate 10 is formed in a rectangular shape, for example, when viewed from the thickness direction, that is, the Z direction. Further, the heating plate 10 has a symmetrical shape with respect to the center line CL1 extending in the width direction, that is, in the X direction. The center line CL1 extending in the width direction of the heating plate 10 means a line at the same distance from both ends in the length direction of the heating plate 10, that is, in the Y direction when viewed from the thickness direction of the heating plate 10.

In the embodiment, the heating plate 10 is formed in a concave shape. Specifically, the heating plate 10 is formed by bending the outer edge of a flat plate-shaped member to the side opposite to the main body 20 side.

As shown in FIG. 2, the heating plate 10 has a heat transfer unit 11, a plurality of heat generating units 12a and 12b, a positioning unit 13, and a rib 14.

Further, on the upper surface of the heating plate 10, a partition portion 15 for partitioning the plurality of heating regions A1 and A2 is formed. The plurality of heating regions A1 and A2 are regions that are heated by the plurality of heat generating portions 12a and 12b, respectively.

FIG. 4 is a bottom view of an example of the heating plate 10. As shown in FIG. 4, a plurality of legs 16 are provided on the lower surface of the heating plate 10.

<Heat transfer part>
The heat transfer unit 11 constitutes the outer shape of the heating plate 10 and is connected to a plurality of heat generating units 12a and 12b. The heat transfer portion 11 is formed of a metal material that conducts heat generated by the plurality of heat generating portions 12a and 12b, and is also formed of a non-magnetic material. As used herein, the term "non-magnetic material" means a material that is not a ferromagnetic material and has a lower magnetic permeability than the plurality of heat generating portions 12a and 12b.

Further, the heat transfer portion 11 is made of a metal material having a smaller electric resistance, that is, an intrinsic resistance than the metal material forming the plurality of heat generating portions 12a and 12b. For example, the metal resistance of the metal material forming the heat transfer portion 11 is preferably 1.5 × 10 ^-8 mΩ or more and less than 3.0 × 10 ^-8 mΩ in an environment of 20 ° C. The metal resistance of the embodiment is 2.7 × ^10-8 mΩ.

Further, the heat transfer portion 11 is made of a metal material having a higher thermal conductivity than the metal material forming the plurality of heat generating portions 12a and 12b.

For example, examples of the material of the heat transfer unit 11 include aluminum and non-magnetic stainless steel. Examples of non-magnetic stainless steel include austenitic stainless steel.

In the embodiment, the heat transfer portion 11 is made of aluminum. Aluminum is not easily affected by a magnetic field, so it is not easily induced and heated. Therefore, by connecting the first heat generating section 12a and the second heat generating section 12b via the heat transfer section 11, it is easy to separate the heating region to be induced and heated. On the other hand, since aluminum is a metal that easily conducts heat, it is easy to conduct heat generated in each of the plurality of heat generating portions 12a and 12b in the heating region. The thermal conductivity of aluminum is 240 W / m · K in an environment of 100 ° C. Further, since aluminum is a lighter metal than iron or the like, the heating plate 10 can be made lighter. Therefore, the heating plate 10 can be easily lifted.

<Heating part>
As shown in FIGS. 2 and 4, the plurality of heat generating portions 12a and 12b are formed on the lower surface of the heating plate 10, that is, the lower surface of the heat transfer portion 11. The plurality of heat generating portions 12a and 12b are aligned in the length direction of the heating plate 10, that is, in the Y direction. Further, the plurality of heat generating portions 12a and 12b are formed apart from each other in the length direction of the heating plate 10, and are connected via the heat transfer portion 11. Specifically, the plurality of heat generating portions 12a and 12b are connected with the heat transfer portion 11 interposed therebetween so as not to be directly connected to each other.

In the embodiment, the plurality of heat generating portions 12a and 12b are provided symmetrically with respect to the center line CL1 of the heating plate 10. The plurality of heat generating portions 12a and 12b are formed in the same size and the same shape. Specifically, the plurality of heat generating portions 12a and 12b are formed in an annular shape, for example. Further, the plurality of heat generating portions 12a and 12b are formed with a plurality of irregularities for positioning when viewed from the lower surface side of the heating plate 10.

The plurality of heat generating portions 12a and 12b are formed in an area larger than the plurality of heating coils 23a and 23b accommodated inside the main body 20 when viewed from the thickness direction of the heating plate 10.

The plurality of heat generating portions 12a and 12b are made of a metal material capable of generating heat by electromagnetic induction. The plurality of heat generating portions 12a and 12b are made of a magnetic material. In other words, the metal material forming the plurality of heat generating portions 12a and 12b has a higher magnetic permeability than the metal material forming the heat transfer portion 11.

The plurality of heat generating portions 12a and 12b are formed of a metal material having a higher electric resistance value than the metal material forming the heat transfer portion 11. For example, the electrical resistance of the metal material forming the plurality of heat generating portions 12a and 12b is preferably 10 × 10 ^-8 mΩ or more and 70 × 10 ^-8 mΩ or less in an environment of 20 ° C. More preferably, the electric resistance of the metal material forming the plurality of heat generating portions 12a and 12b is preferably 60 × 10 ^-8 mΩ or more and 70 × 10 ^-8 mΩ or less.

For example, examples of the material forming the plurality of heat generating portions 12a and 12b include iron and stainless steel. Examples of stainless steel include SUS304 and SUS430. The thermal conductivity of SUS304 and SUS430 is 16 W / m · K and 26 W / m · K, respectively, in an environment of 100 ° C.

<Positioning unit>
As shown in FIG. 2, the positioning portion 13 projects from the lower surface of the heating plate 10 toward the top plate 22 mounted on the main body 20, and is located on the outer edge of the top plate 22. The positioning unit 13 positions the heating plate 10 when the heating plate 10 is placed on the main body 20.

The heating plate 10 has a plurality of positioning portions 13. In the embodiment, the heating plate 10 has four positioning portions 13. The plurality of positioning portions 13 are provided at the four corners of the heating plate 10. Each of the plurality of positioning portions 13 projects from the corner portion of the heating plate 10 toward the main body 20 side. When the heating plate 10 is placed on the main body 20, the plurality of positioning portions 13 are arranged so as to surround the corner portions of the top plate 22, respectively. Each of the plurality of positioning portions 13 is formed of a bent plate-shaped member so as to correspond to the shape of the corner portion of the top plate 22.

By forming the positioning portion 13 on the outer edge of the heating plate 10 in this way, the heating plate 10 can be positioned on the top plate 22 of the main body 20.

<Rib>
As shown in FIGS. 2 and 4, the rib 14 projects from the lower surface of the heating plate 10 toward the top plate 22 mounted on the main body 20 along the length direction of the heating plate 10, that is, the Y direction. , Located on the outer edge of the top plate.

The heating plate 10 has a plurality of ribs 14. In an embodiment, the heating plate 10 has two ribs 14. Each of the plurality of ribs 14 is formed along the outer edge of the heating plate 10 in the length direction. Further, the plurality of ribs 14 extending along the outer edge of the heating plate 10 in the length direction are integrally formed with the positioning portion 13 formed at the corner portion of the heating plate 10. The plurality of ribs 14 are each formed in a plate shape.

FIG. 5A is a cross-sectional view of the induction heating cooker 1 of FIG. 1 cut along the line BB. FIG. 5B is an enlarged partially enlarged cross-sectional view of the Z1 portion of the induction heating cooker 1 of FIG. 5A. As shown in FIGS. 5A and 5B, a plurality of ribs 14 are formed along the outer edge of the heating plate 10 in the length direction, that is, in the Y direction. The plurality of ribs 14 are formed so as to project from the lower surface of the heating plate 10 toward the top plate 22 side, and are arranged along the outer edge 22a in the longitudinal direction of the top plate 22.

The rib 14 is located inside the outer surface 10a of the heating plate 10. The outer side surface 10a is a surface that can be visually recognized from the outside. By arranging the rib 14 inside the outer surface 10a, the influence on the appearance can be reduced.

As shown in FIG. 5B, the lower end 14a of the rib 14 is located below the upper surface 22b of the top plate 22 placed on the main body 20 and above the lower surface 22c of the top plate 22. Therefore, a gap S1 is formed between the lower end 14a of the rib 14 and the main body 20.

In the embodiment, the rib 14 has a thickness equivalent to the thickness of the heat transfer portion 11 in which the heating region of the heating plate 10 is formed. For example, the thickness of the rib 14 may be 0.5 times or more and 1.5 times or less the thickness of the heat transfer portion 11.

In this way, by forming the rib 14 protruding toward the top plate 22 side along the outer edge of the heating plate 10 in the length direction, heat is accumulated at the outer edge of the heating plate 10 in the length direction, and the heating plate is heated. The heat retention of 10 can be increased. Further, the rib 14 can suppress the inflow of air below the heating plate 10 and the deterioration of the heat retention property without impairing the design. Further, the rib 14 can increase the strength of the heating plate 10 and suppress the thermal deformation of the heating plate 10.

Further, by providing the gap S1 between the rib 14 and the main body 20, it is possible to prevent the heat of the heating plate 10 from being directly conducted from the outer edge of the heating plate 10 to the main body 20.

<Partition>
The partition portion 15 partitions a plurality of heating regions A1 and A2 formed on the upper surface of the heating plate 10. In the embodiment, the partition portion 15 is provided on the upper surface of the heating plate 10 along the center line CL1 extending in the width direction of the heating plate 10 when viewed from the thickness direction of the heating plate 10.

In this way, the partition portion 15 partitions the first heating region A1 heated by the first heat generating portion 12a and the second heating region A2 heated by the second heat generating portion 12b.

The partition portion 15 is, for example, a recess extending along the center line CL1 extending in the width direction of the heating plate 10. By forming the partition portion 15 in the concave portion, the cooked food can be easily heated across the first heating region A1 and the second heating region A2.

Further, by forming the partition portion 15 with a concave portion, the thickness of the heat transfer portion 11 at the boundary portion between the first heating region A1 and the second heating region A2 can be made thinner than the thickness of the other flat portion. can. As a result, the area of heat conduction in the partition portion 15 can be reduced, and heat conduction between the first heating region A1 and the second heating region A2 can be suppressed.

<Legs>
The legs 16 extend from the lower surface of the heating plate 10 to the top plate 22 and support the heating plate 10 on the top plate 22. As shown in FIG. 4, the leg portion 16 is provided only on the outside of the plurality of heat generating portions 12a and 12b. Specifically, the legs 16 are provided only on the outside of the plurality of heat generating portions 12a and 12b in the length direction of the heating plate 10, that is, in the Y direction. The legs 16 are formed of, for example, a columnar member extending from the lower surface of the heating plate 10 to the top plate 22.

In an embodiment, the heating plate 10 has a plurality of legs 16. The plurality of legs 16 are aligned at equal intervals in the width direction of the heating plate 10, that is, in the X direction only on the outside of the plurality of heat generating portions 12a and 12b.

By providing the legs 16 on the lower surface of the heating plate 10 in this way, the distance between the heating coils 23a and 23b and the heat generating portions 12a and 12b can be kept constant. Further, by providing the leg portions 16 only on the outside of the plurality of heat generating portions 12a and 12b, the heating plate 10 can be stably supported even if the heating plate 10 is warped due to heat.

[Main body]
The main body 20 has a heating plate 10 placed on the upper surface thereof to heat the heating plate 10. As shown in FIG. 3, in the main body 20, the top plate 22 is placed on the upper surface of the housing 21 that constitutes the outer shape of the main body 20. Further, the main body 20 is provided with an operation display unit 30 on the front surface of the housing 21.

As shown in FIG. 2, the main body 20 accommodates a plurality of heating coils 23a and 23b, a plurality of temperature detection units 24a and 24b, a control board 40, and a cooling fan 51 inside the housing 21. ing.

FIG. 6 is a perspective view of an exemplary induction heating cooker 1 according to an embodiment of the present invention when viewed from below. As shown in FIG. 6, in the main body 20, a lower surface opening 25a is formed on the lower surface of the main body 20 on the one end side in the length direction of the main body 20 to which the cooling fan 51 is attached, that is, in the Y direction. Further, a side surface opening 25b is formed on the side surface on one end side in the length direction of the main body 20. The lower surface opening 25a and the side surface opening 25b are openings for sucking air from the outside to the inside of the main body 20.

On the other hand, a lower surface exhaust port 26a is formed on the lower surface on the other end side of the main body 20 in the length direction. Further, as shown in FIG. 2, a side exhaust port 26b is formed on the side surface on the other end side of the main body 20 in the length direction. The lower surface exhaust port 26a and the side exhaust port 26b are exhaust ports for exhausting air from the inside of the main body 20 to the outside.

Further, as shown in FIG. 6, a connection terminal 27 for connecting a power cord for supplying electric power to the control board 40 is provided on the side surface of the main body 20 on one end side in the length direction.

<Case>
The housing 21 has a first housing 21a and a second housing 21b. The first housing 21a constitutes the outer shape of the upper side of the main body 20. The second housing 21b constitutes the outer shape of the lower side of the main body 20.

<Top plate>
The top plate 22 is an electrically insulating flat plate on which the heating plate 10 is placed on the upper surface. The top plate 22 is made of an electrical insulator such as glass or ceramic. The top plate 22 is placed on the upper surface of the main body 20, that is, the upper surface of the first housing 21a.

<Operation display unit>
The operation display unit 30 includes an operation unit 31 for operating the functions and settings of the induction heating cooker 1 and a display unit 32 for displaying the functions and settings of the induction heating cooker 1. The operation unit 31 determines, for example, switching the power of the induction heating cooker 1 on / off, heating temperature, timer, and / or course selection by operating a switch by the user. The display unit 32 displays, for example, power on / off, a set heating temperature, a set timer, a selected course, and / or a warning when an abnormality is detected. The operation unit 31 and the display unit 32 are controlled by a control unit mounted on the control board 40.

<Heating coil>
The plurality of heating coils 23a and 23b are arranged below the top plate 22, respectively, and are arranged in a region where the plurality of heat generating portions 12a and 12b are projected when viewed from the thickness direction of the heating plate 10, that is, the Z direction. ing. In the embodiment, the plurality of heating coils 23a and 23b are arranged at positions facing the plurality of heat generating portions 12a and 12b, respectively. That is, the plurality of heating coils 23a and 23b have a one-to-one arrangement relationship with the plurality of heat generating portions 12a and 12b, respectively.

In the present specification, the heating coil arranged in the region where the first heat generating portion 12a is projected is referred to as the first heating coil 23a, and the heating coil arranged in the region where the second heating portion 12b is projected is referred to as the second heating coil. It will be described as 23b.

The first heating coil 23a and the second heating coil 23b are each supplied with high-frequency current from a plurality of inverters mounted on the control board 40. As a result, the first heating coil 23a induces and heats the first heat generating portion 12a, while the second heating coil 23b induces and heats the second heat generating portion 12b.

In the embodiment, the first heating coil 23a is attached to the flat plate-shaped mounting plate 52 and is arranged adjacent to the cooling fan 51.

<Temperature detector>
The plurality of temperature detection units 24a and 24b detect the temperatures of the heating regions A1 and A2, respectively. That is, the plurality of temperature detecting units 24a and 24b detect the temperatures of the plurality of heat generating units 12a and 12b, respectively. The plurality of temperature detection units 24a and 24b are arranged at positions on the lower surface of the top plate 22 where the plurality of heating coils 23a and 23b are arranged, respectively. The plurality of temperature detection units 24a and 24b are arranged in a one-to-one relationship with the plurality of heating coils 23a and 23b, respectively.

The plurality of temperature detection units 24a and 24b are composed of, for example, a thermistor or an infrared temperature sensor.

In the present specification, the temperature detection unit that detects the temperature of the first heating region A1 will be referred to as the first temperature detection unit 24a, and the temperature detection unit that detects the temperature of the second heating region A2 will be described as the second temperature detection unit 24b. ..

In the embodiment, the first temperature detection unit 24a is arranged in the center of the first heating coil 23a, and the second temperature detection unit 24b is arranged in the center of the second heating coil 23b. As a result, the temperatures of the first heat generating portion 12a and the second heat generating portion 12b can be measured with higher accuracy.

The temperature information detected by the plurality of temperature detection units 24a and 24b is transmitted to the control unit mounted on the control board 40.

<Control board>
The control board 40 is a board on which a circuit for controlling the induction heating cooker 1 is mounted. FIG. 7 is an exemplary control block diagram of the induction cooker 1. As shown in FIG. 7, the control board 40 includes a control unit 41, a plurality of inverters 42a and 42b, and a plurality of temperature calculation units 43a and 43b. Further, the control unit 41 is connected to the operation unit 31, the display unit 32, and the notification unit 33.

In this specification, the inverter that supplies a high frequency current to the first heating coil 23a will be referred to as a first inverter 42a, and the inverter that supplies a high frequency current to the second heating coil 23b will be referred to as a second inverter 42b. Further, the temperature calculation unit that calculates the temperature of the first heat generation unit 12a based on the temperature information detected by the first temperature detection unit 24a is referred to as the first temperature calculation unit 43a, and the temperature detected by the second temperature detection unit 24b. The temperature calculation unit that calculates the temperature of the second heat generation unit 12b based on the information will be described as the second temperature calculation unit 43b.

The elements constituting the control board 40 are, for example, a memory (not shown) storing a program for functioning these elements and a processing circuit (not shown) corresponding to a processor such as a CPU (Central Processing Unit). And may function as these elements by the processor executing the program.

<Control unit>
The control unit 41 controls the outputs of the plurality of inverters 42a and 42b, respectively. Specifically, the control unit 41 receives information on the heating temperature set by the operation unit 31 from the operation unit 31, and outputs each of the plurality of inverters 42a and 42b based on the received information on the heating temperature. Control.

For example, the user sets the heating temperature of the first heating region A1 via the operation unit 31. The operation unit 31 transmits the information on the set heating temperature to the control unit 41. The control unit 41 receives information on the heating temperature of the first heating region A1 from the operation unit 31, and sets the output of the first inverter 42a based on the received information on the heating temperature. For example, the control unit 41 sets the frequency, output time, and the like of the high frequency current supplied from the first inverter 42a to the first heating coil 23a. Next, the control unit 41 outputs a high frequency current to the first heating coil 23a based on the determined output.

In this way, the control unit 41 controls the output of the first inverter 42a based on the heating temperature of the first heating region A1 set by the operation unit 31. Similarly, the control unit 41 controls the output of the second inverter 42b based on the heating temperature of the second heating region A2 set by the operation unit 31.

By such control, the control unit 41 individually separates the first heating region A1 heated by the first heating unit 12a of the heating plate 10 and the second heating region A2 heated by the second heating unit 12b. The temperature can be adjusted.

Further, the control unit 41 controls the outputs of the plurality of inverters 42a and 42b based on the temperature information detected by the plurality of temperature detection units 24a and 24b. For example, while the heating plate 10 is being heated, the first temperature detection unit 24a detects the temperature information of the first heat generation unit 12a, that is, the temperature information of the first heating region A1. The temperature information detected by the first temperature detection unit 24a is transmitted to the first temperature calculation unit 43a of the control unit 41. The first temperature calculation unit 43a calculates the temperature of the first heat generation unit 12a based on the detected temperature information. The calculated temperature of the first heat generating unit 12a is transmitted to the control unit 41. The control unit 41 compares the calculated temperature of the first heat generation unit 12a with the heating temperature of the first heating region A1 set by the operation unit 31. Based on the comparison result, the control unit 41 adjusts the output of the first inverter 42a so that the temperature of the first heat generation unit 12a becomes the same as the heating temperature set by the operation unit 31.

In this way, the control unit 41 controls the output of the first inverter 42a based on the temperature information of the first heat generation unit 12a detected by the first temperature detection unit 24a, that is, the temperature information of the first heating region A1. ing. Similarly, the control unit 41 controls the output of the second inverter 42b based on the temperature information of the second heat generation unit 12b detected by the second temperature detection unit 24b, that is, the temperature information of the second heating region A2. There is.

By such control, the control unit 41 can easily realize the set heating temperature in the first heating region A1 and the second heating region A2, and can easily maintain the set heating temperature. ..

Further, the control unit 41 transmits, for example, information such as the heating temperature, timer, and / or course of the first heating region A1 and the second heating region A2 set by the operation unit 31 to the display unit 32. The display unit 32 displays the set heating temperature, timer, and / or course information based on the information received from the control unit 41.

Further, the control unit 41 sets the heating temperature of the first heating region A1 and the second heating region A2 based on the temperature information detected by the first temperature detection unit 24a and the second temperature detection unit 24b. If it is determined that the temperature is high, the notification unit 33 is controlled to notify the user. For example, when the preheating is completed, the control unit 41 may notify by sound with a buzzer or the like.

<Inverter>
The plurality of inverters 42a and 42b supply high frequency currents to each of the plurality of heating coils 23a and 23b according to the output set by the control unit 41. FIG. 8 is a circuit diagram of a part of an exemplary control circuit of the induction cooking device 1 according to the embodiment of the present invention. As shown in FIG. 8, the first inverter 42a is connected to the first heating coil 23a via the smoothing capacitor C1. The second inverter 42b is connected to the second heating coil 23b via the smoothing capacitor C1. The first heating coil 23a and the capacitor C2 are connected in parallel, and the second heating coil 23b and the capacitor C3 are connected in parallel.

The plurality of inverters 42a and 42b have switching elements SW1 and SW2, respectively. In the embodiment, the first inverter 42a has a first switching element SW1 and the second inverter 42b has a second switching element SW2.

The first switching element SW1 and the second switching element SW2 are switches that generate high-frequency currents based on pulse waves input from the control unit 41, respectively. That is, the first switching element SW1 and the second switching element SW2 are switches that supply high-frequency currents from the first inverter 42a and the second inverter 42b to the first heating coil 23a and the second heating coil 23b, respectively. The first switching element SW1 and the second switching element SW2 use an insulated gate bipolar transistor (IGBT: Integrated Gate Bipolar Transistor). When a pulse wave is input from the control unit 41, the IGBT converts the direct current supplied from the AC power supply via the DC converter into a high-frequency current corresponding to a desired output. The IGBT converts the direct current into a high frequency current based on the pulse wave set by the control unit 41.

The first inverter 42a is turned on while the pulse wave is input from the control unit 41 to the first switching element SW1. While the first inverter 42a is on, the first switching element SW1 is used to generate a high frequency current based on the pulse wave input from the control unit 41. The first inverter 42a supplies the generated high-frequency current to the first heating coil 23a. The first inverter 42a is turned off when the pulse wave is no longer input from the control unit 41 to the first switching element SW1, and the supply of the high frequency current to the first heating coil 23a is stopped.

Similarly, the second inverter 42b is turned on while the pulse wave is input from the control unit 41 to the second switching element SW2. The second inverter 42b uses the second switching element SW2 to generate a high-frequency current based on the pulse wave input from the control unit 41. The second inverter 42b supplies the generated high frequency current to the second heating coil 23b. The second inverter 42b is turned off when the pulse wave is no longer input from the control unit 41 to the second switching element SW2, and the supply of the high frequency current to the second heating coil 23b is stopped.

As described above, in the induction heating cooker 1, each of the plurality of inverters 42a and 42b uses one switching element (IGBT) to supply a high frequency current to one heating coil. With such a configuration, it is possible to reduce the cost as compared with a configuration in which one inverter uses two switching elements to supply a high frequency current to a plurality of heating coils. Further, since the amount of heat generated can be suppressed, the heat sink for exhausting heat can be reduced. As a result, the induction heating cooker 1 can be made thinner.

<Temperature calculation unit>
The plurality of temperature calculation units 43a and 43b calculate the temperatures of the plurality of heating regions A1 and A2 based on the temperature information detected by the plurality of temperature detection units 24a and 24b, respectively. Specifically, the first temperature calculation unit 43a and the second temperature calculation unit 43b, respectively, from the first temperature detection unit 24a and the second temperature detection unit 24b, respectively, of the first heating region A1 and the second heating region. Receive temperature information. The first temperature calculation unit 43a and the second temperature calculation unit 43b calculate the respective temperatures of the first heating region A1 and the second heating region based on the temperature information. The first temperature calculation unit 43a and the second temperature calculation unit 43b transmit the calculated temperature information to the control unit 41.

<Cooling fan>
As shown in FIG. 2, the cooling fan 51 is a turbo fan that blows cooling air into the main body 20. The cooling fan 51 blows air from the outside of the main body 20 to the inside to cool the plurality of heating coils 23a and 23b, the plurality of inverters 42a and 42b, and the control unit 41 housed inside the main body 20. Specifically, the cooling fan 51 sucks the air outside the main body 20 from the lower surface opening 25a and the side opening 25b provided on one end side of the main body 20 and blows the air into the main body 20.

FIG. 9 is a schematic configuration diagram showing an exemplary internal configuration of the main body. As shown in FIG. 9, the cooling fan 51 has a rotation axis CR1 extending in the thickness direction of the main body 20, that is, in the Z direction. The cooling fan 51 is attached to one end side of the main body 20 in the length direction. Further, the cooling fan 51 is attached to a fan casing 53 integrally formed with a mounting plate 52 to which the first heating coil 23a is attached.

<Fan casing>
FIG. 10 is a schematic partial configuration diagram showing an example of the configuration inside the main body around the cooling fan 51 arranged on one end side of the main body 20. FIG. 11 is another schematic partial configuration diagram showing an example of the configuration inside the main body around the cooling fan 51 arranged on one end side of the main body 20.

As shown in FIGS. 9 to 11, the fan casing 53 is a case in which the cooling fan 51 is housed inside. An intake port 54 for sucking air is provided on the upper surface 53a of the fan casing 53. On the other hand, the lower surface 53b of the fan casing 53 is closed by the second housing 21b as shown in FIG. That is, the lower surface 53b of the fan casing 53 is formed by the second casing 21b.

As shown in FIGS. 9 and 10, the intake port 54 communicates with the lower surface opening 25a provided on the lower surface on one end side of the main body 20. Further, the intake port 54 communicates with the side surface opening 25b provided on the side surface on one end side of the main body 20. Therefore, when the cooling fan 51 is driven, the air outside the main body 20 is sucked from the lower surface opening 25a and the side surface opening 25b. As shown by the arrow FL1 in FIG. 10, the air outside the main body 20 flows into the intake port 54 provided on the upper surface 53a of the fan casing 53 through the lower surface opening 25a and the side surface opening 25b.

The lower surface opening 25a is located above the lower surface 53b of the fan casing 53. That is, the lower surface 53b of the fan casing 53 is located below the lower surface opening 25a. With such a configuration, the air from the lower surface opening 25a easily flows into the intake port 54 provided on the upper surface 53a of the fan casing 53.

The fan casing 53 has an air outlet 55 for blowing air from the cooling fan 51 to the first heating coil 23a on the side surface on the side where the first heating coil 23a is arranged. The air outlet 55 is provided below the lower surface of the mounting plate 52 to which the first heating coil 23a is mounted. As a result, as shown by the arrow FL2 in FIG. 10, the air from the cooling fan 51 is blown toward the first heating coil 23a through the air outlet 55.

As described above, the cooling fan 51 takes in cooling air from the intake port 54 provided on the upper surface 53a of the fan casing 53, and first heats the air from the air vent 55 provided on the side surface of the fan casing 53. It is blowing air to 23a.

With such a configuration, it is possible to increase the amount of air blown into the main body 20 in order to cool the plurality of heating coils 23a and 23b, so that the cooling effect can be improved.

Further, since the intake port 54 is provided on the upper surface 53a of the fan casing 53, the inflow of water can be suppressed. For example, even if there is water below the bottom of the main body 20, air can be taken in from the intake port 54 provided on the upper surface 53a of the fan casing 53, so that it is difficult for water to be sucked into the intake port 54. Therefore, it is possible to suppress the inflow of water from the intake port 54 of the fan casing 53.

Further, since air is taken in from the intake port 54 provided on the upper surface 53a of the fan casing 53, the lower surface 53b of the fan casing 53 can be closed. Therefore, the cooling fan 51 can be arranged close to the bottom surface of the main body 20. That is, the height of the main body 20 can be lowered. As a result, according to the induction heating cooker 1, the thickness of the device can be reduced as compared with the configuration in which the intake port is provided on the lower surface of the fan casing. As a result, the induction heating cooker 1 can be downsized.

Inside the main body 20, a partition rib 56 for partitioning a region where the cooling fan 51 is arranged and a region where the first heating coil 23a is arranged is provided. The partition rib 56 partitions a flow path through which air flows from the outside of the main body 20 to the intake port 54 of the fan casing 53 and a flow path through which air flows from the air outlet 55 of the fan casing 53 to the first heating coil 23a. There is. Specifically, the partition rib 56 is formed of a plate-shaped member extending from the upper surface of the mounting plate 52 to which the first heating coil 23a is attached toward the upper surface of the main body 20.

With such a configuration, the air flow from the first heating coil 23a side to the intake port 54 of the fan casing 53 can be blocked by the partition rib 56. As a result, it is possible to prevent the air warmed by the heat of the first heating coil 23a from being sucked into the intake port 54.

As shown in FIG. 11, inside the main body 20, a draining rib 57 extending in the thickness direction of the main body 20, that is, in the Z direction is formed in the flow path between the side opening 25b and the intake port 54 of the fan casing 53. ing. The draining rib 57 is a plate-shaped member extending in the width direction of the main body 20, that is, in the X direction. The upper surface 57a of the draining rib 57 is formed at a position higher than the intake port 54 of the fan casing 53.

With such a configuration, when water enters the inside of the main body 20 from the outside of the main body 20 through the side opening 25b, the draining rib 57 can prevent the water from flowing into the intake port 54. ..

Further, a connection terminal 27 for connecting a power cord that supplies electric power to the induction heating cooker 1 is provided on the side surface of the main body 20 on one end side. By not providing the connection terminal 27 on the other end side where the exhaust ports 26a and 26b are provided in this way, it is possible to prevent the connection terminal 27 from becoming hot due to the air warmed inside the main body 20.

[Heating control]
Next, an exemplary heating control of the induction cooking device 1 will be described.

FIG. 12A is a diagram showing an example of heating control of the induction heating cooker 1 according to the embodiment of the present invention. FIG. 12A shows the control of the output of the first inverter 42a by the control unit 41, the control of the output of the second inverter 42b, and the overall output. The total output means the total of the output of the first inverter 42a and the output of the second inverter 42b. Further, the control shown in FIG. 12A indicates control of the outputs of the first inverter 42a and the second inverter 42b when both the first heating region A1 and the second heating region A2 of the heating plate 10 are heated at the same heating temperature. ..

As shown in FIG. 12A, when the control unit 41 heats both the first heating region A1 and the second heating region A2 of the heating plate 10 at the same heating temperature, the control unit 41 has both the first inverter 42a and the second inverter 42b. Set the output to P1. P1 is, for example, the output of the inverter calculated based on the heating temperature set by the operation unit 31. That is, P1 is an output corresponding to a desired heating temperature set by the user.

Next, the control unit 41 sequentially switches the output of the first inverter 42a and the output of the second inverter 42b by sequentially switching the on / off of the first inverter 42a and the second inverter 42b. As a result, the supply of the high frequency current from the first inverter 42a to the first heating coil 23a and the supply of the high frequency current from the second inverter 42b to the second heating coil 23b are sequentially switched. As a result, the first heating region A1 and the second heating region A2 are sequentially heated by sequentially inducing and heating the first heat generating portion 12a and the second heating portion 12b. As a result, the first heating region A1 and the second heating region A2 are heated to the same temperature.

In the embodiment, the control unit 41 controls two inverters 42a and 42b, and alternately switches between the output of the first inverter 42a and the output of the second inverter 42b. That is, the control unit 41 alternately switches between supplying a high-frequency current from the first inverter 42a to the first heating coil 23a and supplying a high-frequency current from the second inverter 42b to the second heating coil 23b.

Specifically, when the control unit 41 starts heating, the control unit 41 turns on the first inverter 42a by inputting a pulse wave to the first switching element SW1. While the first inverter 42a is on, the first inverter 42a generates a high frequency current based on the pulse wave input from the control unit 41. The first inverter 42a supplies the generated high-frequency current to the first heating coil 23a. Here, the control unit 41 starts the output of the first inverter 42a from 0 and gradually increases it to P1.

When the output of the first inverter 42a reaches P1, the control unit 41 stops the input of the pulse wave to the first switching element SW1 and switches the first inverter 42a from on to off. As a result, the supply of the high frequency current from the first inverter 42a to the first heating coil 23a is stopped. That is, the output of the first inverter 42a is stopped.

Next, the control unit 41 switches the second inverter 42b from off to on by inputting a pulse wave to the second switching element SW2. While the second inverter 42b is on, the second inverter 42b generates a high frequency current based on the pulse wave input from the control unit 41. The second inverter 42b supplies the generated high frequency current to the second heating coil 23b. Here, the control unit 41 starts the output of the second inverter 42b from 0 and gradually increases it to P1.

When the output of the second inverter 42b reaches P1, the control unit 41 stops the input of the pulse wave to the second switching element SW2 and switches the second inverter 42b from on to off. As a result, the supply of the high frequency current from the second inverter 42b to the second heating coil 23b is stopped. That is, the output of the second inverter 42b is stopped.

In the heating control shown in FIG. 12A, the output of the first inverter 42a and the output of the second inverter 42b described above are sequentially switched to sequentially heat the first heating coil 23a and the second heating coil 23b.

In this way, the control unit 41 alternately switches between the output of the first inverter 42a and the output of the second inverter 42b to set the overall output to P1. As a result, the entire surface of the heating plate 10 can be uniformly heated at a predetermined heating temperature.

Further, by alternately switching the output of the first inverter 42a and the output of the second inverter 42b, the supply of the high frequency current from the first inverter 42a and the supply of the high frequency current from the second inverter 42b are alternately performed. There is. That is, when the high frequency current is being supplied from the first inverter 42a to the first heating coil 23a, the supply of the high frequency current from the second inverter 42b to the second heating coil 23b is stopped. On the other hand, when the high frequency current is being supplied from the second inverter 42b to the second heating coil 23b, the supply of the high frequency current from the first inverter 42a to the first heating coil 23a is stopped.

Further, since the high frequency current is not supplied to the first heating coil 23a and the second heating coil 23b at the same time, the electromagnetic wave generated from the first heating coil 23a and the electromagnetic wave generated from the second heating coil 23b do not interfere with each other. Therefore, it is possible to suppress the generation of interference sound due to the interference of these electromagnetic waves.

When both the first inverter 42a and the second inverter 42b are turned on and a high frequency current is simultaneously supplied to the plurality of heating coils 23a and 23b, interference noise may occur. For example, if the output of the first inverter 42a and the output of the second inverter 42b are different, the frequency of the high frequency current will be different, and the electromagnetic waves generated from the respective inverters may interfere with each other to generate an interference sound. be. According to the induction heating cooker 1, in order to switch the first inverter 42a and the second inverter 42b on and off alternately, a high frequency current is alternately supplied to the first heating coil 23a and the second heating coil 23b. Therefore, high frequency currents are not supplied to the plurality of heating coils 23a and 23b at the same time, and it is possible to suppress the generation of interference noise. That is, according to the induction heating cooker 1, it is possible to suppress the generation of an interference sound that makes the user feel uncomfortable.

Further, the control unit 41 starts the output of the first inverter 42a from 0 each time when the first inverter 42a is switched from off to on, and gradually increases it to P1. Further, the control unit 41 starts the output of the second inverter 42b from 0 each time when the second inverter 42b is switched from off to on, and gradually increases it to P1.

As described above, each time the control unit 41 switches between the output of the first inverter 42a and the output of the second inverter 42b, the control unit 41 lowers the output of the first inverter 42a and the second inverter 42b at the start of output. By controlling in this way, it is possible to reduce the load applied to the first inverter 42a and the second inverter 42b when the output of the first inverter 42a and the output of the second inverter 42b are switched.

FIG. 12B is a diagram showing another example of heating control of the induction cooking device 1 according to the embodiment of the present invention. In the heating control shown in FIG. 12B, the control unit 41 sets the next output based on the previous output information of the first inverter 42a and the second inverter 42b. The heating control shown in FIG. 12B is the same as the heating control shown in FIG. 12A in that the control unit 41 sequentially switches between the output of the first inverter 42a and the output of the second inverter 42b.

As shown in FIG. 12B, the control unit 41 stores the output information of the first inverter 42a when the first inverter 42a is on and the output information of the second inverter 42b when the second inverter 42b is on. .. The control unit 41 controls the outputs of the first inverter 42a and the second inverter 42b based on the stored output information.

For example, when the control unit 41 starts heating, a pulse wave is input to the first switching element SW1 to turn on the first inverter 42a. As a result, the supply of high frequency current from the first inverter 42a to the first heating coil 23a is started. When the supply of the high frequency current is started, the control unit 41 gradually increases the output of the first inverter 42a from 0 to P1.

Further, the control unit 41 stores the output information of the first inverter 42a when the first inverter 42a is on. The output information includes, for example, the output of the first inverter 42a and the output time.

Next, the control unit 41 sets the output of the first inverter 42a when the first inverter 42a is turned on next, based on the stored output information. The details of the setting of the output of the inverter based on the output information will be described in "Details of heating control" described later.

When the first output of the previous first inverter 42a is P1 in the stored output information, the control unit 41 sets the second output of the first inverter 42a to be output next to P1. Specifically, the control unit 41 is set so that the second output of the first inverter 42a is not started from 0 and gradually increased to P1, but is started from the beginning at P1.

Further, the control unit 41 sets the second output time ts ₂ of the next first inverter 42a based on the first output time ts ₁ of the previous first inverter 42a in the stored output information. The output time is the time when the pulse wave is input to the switching element and the inverter is turned on, that is, the time when the inverter supplies the high frequency current to the heating coil.

In the heating control shown in FIG. 12B, when the first inverter 42a is turned on for the second time or later, the control unit 41 sets P1 constant without reducing the output of the first inverter 42a. Further, the control unit 41 sets the output times ts ₁ , ts ₂ , and ts ₃ to the same time.

The control unit 41 also controls the output of the second inverter 42b in the same manner as the control of the output of the first inverter 42a. That is, when the second inverter 42b is turned on for the second time or later, the control unit 41 sets P1 constant without reducing the output of the second inverter 42b. Further, the control unit 41 sets the output times ts ₁₁ , ts ₁₂ , and ts ₁₃ to the same time.

By controlling in this way, high-frequency current can be efficiently output from the first inverter 42a and the second inverter 42b, and the heating plate 10 can be efficiently heated.

In the heating control shown in FIG. 12B, the control unit 41 does not reduce the outputs of the first inverter 42a and the second inverter 42b when the first inverter 42a and the second inverter 42b are turned on for the second time or later. The example in which P1 is constant has been described, but the present invention is not limited to this. For example, the control unit 41 may change the next output based on the previous output of the first inverter 42a and the second inverter 42b.

Further, in the heating control shown in FIG. 12B, the control unit 41 sets the output times ts ₁ , ts ₂ , and ts ₃ of the first inverter 42a to the same time, and the output times ts ₁₁ and ts ₁₂ of the second inverter 42b. , Ts ₁₃ have been set to the same time, but the present invention is not limited to this. For example, the control unit 41 sets the next output times ts ₂ and ts ₁₂ to different times from the previous output times ts ₁ and ts ₁₁ based on the previous outputs of the first inverter 42a and the second inverter 42b. May be good.

[Details of heating control]
Next, an example of detailed heating control of the induction heating cooker 1 will be described.

FIG. 13 is a diagram showing an example of detailed heating control of the induction cooking device 1 according to the embodiment of the present invention. FIG. 13 shows an example of pulse wave control of the control unit 41. In FIG. 13, a first pulse wave input to the first switching element SW1 of the first inverter 42a and a second pulse wave input to the second switching element SW2 of the second inverter 42b are shown.

As shown in FIG. 13, the control unit 41 inputs the first pulse wave to the first switching element SW1 of the first inverter 42a and the second pulse wave to the second switching element SW2 of the second inverter 42b. And, are performed alternately. As a result, the control unit 41 alternately supplies the high-frequency current from the first inverter 42a to the first heating coil 23a and the high-frequency current from the second inverter 42b to the second heating coil 23b. ..

The control of the first pulse wave of the control unit 41 that controls the output of the first inverter 42a will be described. The control unit 41 sets the output of the first inverter 42a, for example, based on the heating temperature set by the operation unit 31. Specifically, the control unit 41 sets the on-time of the first pulse wave input to the first switching element SW1 of the first inverter 42a. The control unit 41 sets the first frequency f1 of the _first pulse wave by setting the on-time of the first pulse wave under the condition that the on / off duty of the first pulse wave is constant. .. Further, the control unit 41 sets the first output time ts ₁ based on the on-time of the first pulse wave.

The control unit 41 turns on the first inverter 42a by inputting the first pulse wave to the first switching element SW1. During the first output time ts ₁ when the first inverter 42a is on, the first inverter 42a uses the first switching element SW1 to generate a high frequency DC current based on the first pulse wave input from the control unit 41. Convert to electric current. As a result, the first inverter 42a supplies a high frequency current to the first heating coil 23a. At this time, the control unit 41 stores the last on-time t ₁ of the first pulse wave in the first output time ts ₁ .

The control unit 41 is based on the last on-time t ₁ of the first pulse wave in the first output time ts ₁ , and then the first pulse wave in the second output time ts ₂ when the first inverter 42a is turned on. Set the first on-time t ₂ of.

In the embodiment, the control unit 41 sets the first on-time t 2 of the first pulse wave in the second output time ts ₂ when the first inverter 42a is turned on next, and the first on-time t ₂ in the first output time ts ₁ . Set to the same as the last on-time t ₁ of one pulse wave.

As a result, the control unit 41 can set the _second frequency f2 of the first pulse wave in the second output time ts ₂ when the first inverter 42a is turned on next. In the embodiment, the control unit 41 sets the second frequency f ₂ to be the same as the first frequency f ₁ .

Further, the control unit 41 sets the second output time ts ₂ based on the first on-time t ₂ of the first pulse wave in the second output time ts ₂ . In the embodiment, the first on-time t ₂ of the first pulse wave at the second output time ts ₂ is set to be the same as the last on-time t ₁ of the first pulse wave at the first output time ts ₁ . Therefore, the second output time ts ₂ is set to the same time as the first output time ts ₁ .

As described above, the control unit 41 is based on the last on-time t ₁ of the first pulse wave when the first inverter 42a was turned on last time, and then the first pulse wave when the first inverter 42a is turned on. The first on-time t ₂ of is set. As a result, the first inverter 42a can output the next first inverter 42a based on the previous output information. As a result, the first heating region A1 of the heating plate 10 can be efficiently heated.

The control of the second pulse wave of the control unit 41 that controls the output of the second inverter 42b is the same as the control of the first pulse wave.

The control unit 41 sets the on-time of the second pulse wave input to the second switching element SW2 of the second inverter 42b. Next, the control unit 41 turns on the second inverter 42b by inputting the second pulse wave to the second switching element SW2. During the first output time ts ₁₁ when the second inverter 42b is on, the second inverter 42b uses the second switching element SW2 to generate a high frequency DC current based on the second pulse wave input from the control unit 41. Convert to electric current. As a result, the second inverter 42b supplies a high frequency current to the second heating coil 23b. At this time, the control unit 41 stores the last on-time t ₁₁ of the second pulse wave in the first output time ts ₁₁ .

The control unit 41 sets the first on-time t ₁₂ of the second pulse wave at the second output time ts ₁₂ based on the last on-time t ₁₁ of the second pulse wave at the first output time ts ₁₁ . As a result, the control unit 41 sets the second frequency _f12 of the second pulse wave of the second inverter 42b in the second output time ts ₁₂ .

In the embodiment, the control unit 41 has the same first frequency f ₁₁ of the second pulse wave at the first output time ts ₁₁ and the second frequency f ₁₂ of the second pulse wave at the second output time ts ₁₂ . It is set. Further, the control unit 41 sets the second output time ts ₁₂ to the same time as the first output time ts ₁₁ .

In this way, the control unit 41 stores the last on-time of the pulse wave in the previous output time as output information, and based on the last on-time of the pulse wave, sets the first on-time of the next pulse wave. It is set. By performing such control, the output of the inverter can be controlled by inheriting the previous output information, so that each heating region of the heating plate 10 can be efficiently heated.

In the heating control shown in FIG. 13, the control unit 41 has the same first output times ts ₁ and ts ₁₁ and second output times ts ₂ and ts ₁₂ in the first inverter 42a and the second inverter 42b, respectively. An example of setting has been described, but the present invention is not limited to this. For example, when the heating temperature setting is changed during heating, the control unit 41 sets the first output times ts ₁ and ts ₁₁ and the second output times ts ₂ and ts ₁₂ to different times, respectively. You may.

Further, the output times ts ₁ and ts ₂ of the first inverter 42a may be different from the output times ts ₁₁ and ts ₁₂ of the second inverter 42b. The output times ts ₁ , ts ₂ , ts ₁₁ and ts ₁₂ may be set according to the magnitude of each output of the first inverter 42a and the second inverter 42b.

Further, the control unit 41 compares the outputs of the plurality of inverters 42a and 42b in the drive cycles tc ₁ and tc ₂ in which the on / off of the plurality of inverters 42a and 42b is switched, and based on the difference in the outputs, the drive cycle tc ₁ , Tc ₂ may be adjusted.

The drive cycles tc ₁ and tc ₂ mean the period from when the first inverter 42a is turned on to when the first inverter 42a is turned on next. In other words, the drive cycles ct ₁ and ct ₂ mean the period from the input of the first pulse wave to the next input of the first pulse wave. As shown in FIG. 13, the drive cycle ct ₁ is a period obtained by totaling the first output time ts ₁ of the first pulse wave and the first output time ts ₁₁ of the second pulse wave. Further, the drive cycle ct ₂ is a period obtained by totaling the second output time ts ₂ of the first pulse wave and the second output time ts ₁₂ of the second pulse wave.

For example, the control unit 41 compares the outputs of the plurality of inverters 42a and 42b (that is, the consumption output of the induction heating cooker and the output per second) in the drive cycles ct ₁ and tc ₂ , and outputs (that is, the induction). When the difference (which is the consumption output of the cooking device and the output per second) is relatively large, the drive cycles tc ₁ and tc ₂ may be longer than in the case where the difference is relatively small. Alternatively, the control unit 41 compares the outputs of the plurality of inverters 42a and 42b in the drive cycles tc ₁ and tc ₂ , and when the difference between the outputs is relatively small, the drive cycle is compared with the case where the difference is relatively large. ct ₁ and ct ₂ may be shortened.

By such control, equipment such as lighting around the plurality of heating coils 23a and 23b is affected, and it is possible to prevent the equipment from malfunctioning.

In the heating control shown in FIG. 13, the control unit 41 sets the first on-time t ₂ , t ₁₂ of the pulse wave at the second output time ts ₂ and ts ₁₂ to the pulse at the first output time ts ₁ and ts ₁₁ . An example of setting the same as the last on-time t ₁ and t ₁₁ of the wave has been described, but the present invention is not limited to this. The control unit 41 sets the first on-time t ₂ and t ₁₂ of the pulse wave at the second output times ts ₂ and ts ₁₂ to the last on-time t ₁ and t 12 of the pulse wave at the first output times ts ₁ and ts ₁₁ . It may be set differently from ₁₁ .

For example, a case where the target output P1 set by the control unit 41 is not reached in the first output time ts ₁ of the first inverter 42a will be described. In this case, the control unit 41 sets the first on-time t2 of the first pulse wave at the _second output time ts ₂ and the last on-time of the first pulse wave at the first output time ts ₁ for the first inverter 42a. It may be set longer than t ₁ .

With such control, the inverter can be set to an appropriate output and can be quickly heated to a desired heating temperature.

[effect]
According to the induction heating cooker 1 according to the first embodiment, the following effects can be obtained.

In the induction heating cooker 1, the heating plate 10 has a plurality of heat generating portions 12a and 12b. Further, the plurality of heating coils 23a and 23b are arranged in the regions where the plurality of heat generating portions 12a and 12b are projected when viewed from the thickness direction of the heating plate 10. With such a configuration, a plurality of heating regions A1 and A2 to be heated by the plurality of heat generating portions 12a and 12b are formed on one heating plate 10, and the plurality of heating regions A1 and A2 are individually heated. Can be done.

Further, the heating temperature of each of the plurality of heating regions A1 and A2 can be individually adjusted by the control unit 41. Therefore, according to the induction heating cooker 1, it is possible to realize the heating temperature set by the user in each of the plurality of heating regions A1 and A2. As a result, the user can heat the cooked food at the set heating temperature in each of the plurality of heating regions A1 and A2. Therefore, according to the induction heating cooker 1, convenience can be improved.

The plurality of heat generating portions 12a and 12b are formed of a metal material having a higher electric resistance value than the metal material forming the heat transfer portion 11. With such a configuration, it is possible to facilitate induction heating of the plurality of heat generating portions 12a and 12b and to prevent induction heating of the heat transfer portion 11. As a result, the plurality of heating regions A1 and A2 can be easily separated and the temperature can be easily adjusted, so that the convenience can be further improved.

The heating plate 10 has a shape symmetrical with respect to the center line CL1 of the heating plate 10 extending in the width direction. Further, the plurality of heat generating portions 12a and 12b are provided symmetrically with respect to the center line CL1 of the heating plate 10. With such a configuration, the heating plate 10 can be placed on the main body 20 without distinguishing the left-right direction. As a result, convenience is further improved.

The heating plate 10 has a positioning portion 13 that protrudes from the lower surface of the heating plate 10 toward the top plate 22 side and is located on the outer edge 22a of the top plate 22. With such a configuration, when the heating plate 10 is placed on the top plate 22, the heating plate 10 can be easily positioned on the top plate 22. As a result, convenience is further improved.

The heating plate 10 has ribs 14 that project from the lower surface of the heating plate toward the top plate 22 side along the length direction of the heating plate 10 and are located on the outer edge 22a of the top plate 22. With such a configuration, it is possible to prevent the heating plate 10 from warping due to thermal deformation. Further, by accumulating heat in the rib 14, the heat retention of the outer edge of the heating plate 10 can be improved. Further, it is possible to suppress the passage of wind below the heating plate 10 and improve the heat retention property.

The lower end 14a of the rib 14 is located below the upper surface 22b of the top plate 22 and above the lower surface 22c of the top plate 22. With such a configuration, a gap S1 can be formed between the lower end 14a of the rib 14 and the upper surface of the main body 20. That is, since the rib 14 does not come into contact with the main body 20, it is possible to suppress heat conduction from the rib 14 to the main body 20.

The heating plate 10 has legs 16 extending from the lower surface of the heating plate 10 to the top plate 22 only on the outside of the plurality of heat generating portions 12a and 12b. With such a configuration, the heating plate 10 can be stably placed on the top plate 22.

The heating plate 10 can be cooked over a plurality of heating regions A1 and A2 heated by the plurality of heat generating portions 12a and 12b, and has a partition portion 15 for partitioning the plurality of heating regions A1 and A2. With such a configuration, the cooked food can be heated across the plurality of heating regions A1 and A2, while the cooked food is partitioned by the partition portion 15 and the cooked food is heated in each of the plurality of heated regions A1 and A2. You can also. As a result, convenience is further improved.

The partition portion 15 is a recess provided on the upper surface of the heating plate 10 along the center line CL1 extending in the width direction of the heating plate 10 when viewed from the thickness direction of the heating plate 10. With such a configuration, it is easy to move the cooked food between the plurality of heating regions A1 and A2, so that the cooked food can be heated more easily across the plurality of heating regions A1 and A2. As a result, convenience is further improved.

The rib 14 is located inside the outer surface 10a of the heating plate 10. With such a configuration, the rib 14 can be provided without spoiling the appearance of the heating plate 10.

[Example 1]
FIG. 14 is a graph showing an example of experimental results when a heating experiment was performed in the induction heating cooker according to the embodiment of the present invention. In the graph shown in FIG. 14, the first heating region A1 when the first heating region A1 of the heating plate 10 is heated to the first target heating temperature Tg1 and the second heating region A2 is heated to the second target heating temperature Tg2. And the result of measuring the temperature in the 2nd heating region A2 are shown. The first target heating temperature Tg1 is 250 ° C., and the second target heating temperature Tg2 is 90 ° C. The first target heating temperature Tg1 and the second target heating temperature Tg2 are heating temperatures set by the operation unit 31.

As shown in FIG. 14, the measured temperature of the first heating region A1 reaches the first target heating temperature Tg1 in about 200 seconds and maintains the first target heating temperature Tg1. Further, the measured temperature of the second heating region A2 also reaches the second target heating temperature Tg2 in about 200 seconds and maintains the second target heating temperature Tg2.

As described above, according to the induction heating cooker 1, the heating temperature is individually adjusted to the first target heating temperature Tg1 and the second target heating temperature Tg2 in the first heating region A1 and the second heating region A2, respectively, with high accuracy. can do. That is, even if the left and right heating temperatures are different between the first heating region A1 and the second heating region A2, the temperatures of the respective heating regions A1 and A2 can be adjusted with high accuracy.

Further, according to the induction heating cooker 1, the heating plate 10 can be efficiently heated and heated to a desired heating temperature in a short time.

Further, according to the induction heating cooker 1, since the temperature is adjusted while detecting the temperatures of the first heating region A1 and the second heating region A2, the temperatures of the first heating region A1 and the second heating region A2 are set respectively. The first target heating temperature Tg1 and the second target heating temperature Tg2 can be maintained.

In the embodiment, the heating plate 10 has been described with a thin plate-shaped flat plate as an example, but the heating plate 10 is not limited thereto. For example, the heating plate 10 may be a plate having a plurality of hemispherical recesses, a so-called takoyaki plate, a plate having a plurality of rectangular recesses, or a plate in which these plates are combined. In the combined plate, for example, the first heating region A1 may be a flat plate and the second heating region A2 may be a takoyaki plate. Further, the shape of the heating plate 10 when viewed from the thickness direction is not limited to the rectangular shape. For example, the shape of the heating plate 10 when viewed from the thickness direction may be a square, a circle, an ellipse, or the like.

In the embodiment, an example in which the heating plate 10 has two heat generating portions 12a and 12b has been described, but the heating plate 10 is not limited thereto. The heating plate 10 may have two or more heat generating portions. Further, the example in which the plurality of heat generating portions 12a and 12b are formed in a ring shape has been described, but the present invention is not limited thereto. The shape of the plurality of heat generating portions 12a and 12b may be, for example, a circle, an ellipse, a triangle, a square, a rectangle, or a polygon.

Further, an example in which the plurality of heat generating portions 12a and 12b are formed in the same size and the same shape has been described, but the present invention is not limited thereto. For example, the plurality of heat generating portions 12a and 12b may be formed in different sizes and shapes, respectively.

In the embodiment, an example in which the heating plate 10 has a symmetrical shape with respect to the center line CL1 extending in the width direction has been described, but the heating plate 10 is not limited thereto. Further, the example in which the plurality of heat generating portions 12a and 12b are provided symmetrically with respect to the center line CL1 has been described, but the present invention is not limited thereto. For example, by forming the heating plate 10 and the plurality of heat generating portions 12a and 12b so as to have different shapes on the left and right, the mounting direction can be fixed when the heating plate 10 is mounted on the main body 20. This makes it possible to prevent the heating plate 10 from being attached to the main body 20 in the wrong direction.

In the embodiment, the example in which the heating plate 10 has a plurality of positioning portions 13 has been described, but the heating plate 10 is not limited thereto. The heating plate 10 may have one or more positioning portions 13. Further, the example in which the plurality of positioning portions 13 are formed at the corners of the heating plate 10 has been described, but the present invention is not limited thereto. The plurality of positioning portions 13 may be located on the outer edge of the top plate 22 placed on the main body 20.

Further, the example in which the heating plate 10 is positioned on the top plate 22 by the positioning unit 13 has been described, but the present invention is not limited thereto. For example, the heating plate 10 may be positioned by a frame attached to the outer edge of the main body 20.

FIG. 15 is a schematic configuration diagram of an example of a state in which the frame 60 is attached to the induction heating cooker 1 according to the embodiment of the present invention. As shown in FIG. 15, the frame 60 is arranged so as to surround the outer edge of the heating plate 10. Further, the frame 60 has a frame leg portion 61 extending below the top plate 22 and in contact with the outer edge of the main body 20 on which the top plate 22 is placed. In the example shown in FIG. 15, the frame 60 has a plurality of frame legs 61 that come into contact with the plurality of corners of the main body 20. With such a configuration, when the heating plate 10 is arranged inside the frame 60, the outer edge of the heating plate 10 comes into contact with the inner wall of the frame 60. Thereby, the heating plate 10 can be positioned by the frame 60 in a state of being placed on the top plate 22.

In the embodiment, an example in which the heating plate 10 has a plurality of ribs 14 has been described, but the heating plate 10 is not limited thereto. The heating plate 10 may have one or more ribs 14. Further, the example in which the rib 14 is integrally formed with the positioning portion 13 has been described, but the present invention is not limited to this. The rib 14 may be formed of a member separate from the positioning portion 13.

In the embodiment, the example in which the partition portion 15 is formed in the concave portion has been described, but the present invention is not limited thereto. The partition portion 15 may be formed of, for example, a convex portion. With such a configuration, the user can cook the cooked food heated in the first heating region A1 and the cooked food heated in the second heating region A2 so as not to be mixed.

Further, the example in which the partition portion 15 is provided along the center line CL1 extending in the width direction of the heating plate 10 has been described, but the present invention is not limited thereto. The partition portion 15 may be capable of partitioning the plurality of heating regions A1 and A2, and may be provided on the upper surface of the heating plate 10 between the plurality of heat generating portions 12a and 12b.

In the embodiment, an example in which the heating plate 10 has a plurality of cylindrical legs 16 has been described, but the heating plate 10 is not limited thereto. For example, the leg portion 16 may have an elliptical shape or a polygonal shape.

In the embodiment, the first heating coil 23a and the second heating coil 23b are one-to-one in the region where the first heat generating portion 12a and the second heating portion 12b are projected when viewed from the thickness direction of the heating plate 10, respectively. The example in which they are arranged facing each other has been described, but the present invention is not limited to this. A plurality of heating coils may be arranged to face each of the first heating unit 12a and the second heating unit 12b. For example, a plurality of first heating coils 23a may be arranged concentrically in the region where the first heat generating portion 12a is projected. Similarly, a plurality of second heating coils 23b may be arranged concentrically in the region where the second heat generating portion 12b is projected.

In the embodiment, an example in which the plurality of temperature detection units 24a and 24b are arranged in the center of the plurality of heating coils 23a and 23b has been described, but the present invention is not limited thereto.

In the embodiment, the example in which the openings are the lower surface opening 25a and the side surface opening 25b has been described, but the present invention is not limited thereto. The opening may be either a lower surface opening 25a or a side surface opening 25b. Similarly, the example in which the exhaust port is the lower surface exhaust port 26a and the side exhaust port 26b has been described, but the present invention is not limited thereto. The exhaust port may be either a lower surface exhaust port 26a or a side exhaust port 26b.

In the embodiment, the example in which the cooling fan 51 is a turbo fan has been described, but the present invention is not limited thereto. The cooling fan 51 may be any fan that can take in air from the intake port 54 provided on the upper surface 53a of the fan casing 53 and blow air from the air blowing port 55 provided on the side surface of the fan casing 53.

In the embodiment, the example in which the lower surface 53b of the fan casing 53 is formed by the second housing 21b has been described, but the present invention is not limited thereto. The fan casing 53 may be formed of an integral member including the lower surface 53b. Further, the lower surface 53b of the fan casing 53 may be formed of a member different from the second housing 21b, or may be formed by a combination of the second housing 21b and another member.

Although the present invention has been fully described in connection with preferred embodiments with reference to the accompanying drawings, various modifications and modifications are obvious to those skilled in the art. It should be understood that such modifications and modifications are included within the scope of the invention as long as it does not deviate from the scope of the invention according to the appended claims.

Since the induction heating cooker according to the present invention can improve the convenience of the user in cooking, it is useful for, for example, an induction heating cooker placed on a tabletop or a gas table.

1 Induction heating cooker 10 Heating plate 10a Outer side surface 11 Heat transfer unit 12a Heat generation unit (first heat generation unit)
12b Heat generation part (second heat generation part)
13 Positioning part 14 Rib 14a Lower end 15 Partition part 16 Leg part 20 Main body 21a First housing 21b Second housing 22 Top plate 22a Outer edge 22b Top surface 22c Bottom surface 23a Heating coil (first heating coil)
23b Heating coil (second heating coil)
24a Temperature detection unit (1st temperature detection unit)
24b Temperature detection unit (second temperature detection unit)
25a Bottom opening (opening)
25b Side opening (opening)
26a Bottom exhaust port (exhaust port)
26b Side exhaust port (exhaust port)
27 Connection terminal 31 Operation unit 32 Display unit 33 Notification unit 40 Control board 41 Control unit 42a Inverter (first inverter)
42b Inverter (second inverter)
43a Temperature calculation unit (1st temperature calculation unit)
43b Temperature calculation unit (second temperature calculation unit)
51 Cooling fan 52 Mounting plate 53 Fan casing 53a Top surface 53b Bottom surface 54 Intake port 55 Blower port 56 Partition rib 57 Draining rib 57a Top surface 58 Through hole 60 Frame 61 Frame leg

Claims (6)

A tabletop induction heating cooker comprising a plurality of heat generating parts to be induced and heated, and a heating plate having a heat transfer part for conducting heat generated by the plurality of heat generating parts, and a main body.
A top plate placed on the upper surface of the main body and on which the heating plate is placed,
A plurality of heatings arranged below the top plate, respectively arranged in a plurality of regions where the plurality of heat generating portions are projected when viewed from the thickness direction of the heating plate, and inducing and heating the plurality of heat generating portions. With the coil
A plurality of inverters that supply high-frequency currents to the plurality of heating coils, respectively.
A control unit that controls the output of each of the plurality of inverters,
Equipped with
The heating plate has ribs that project from the lower surface of the heating plate toward the top plate side along the length direction of the heating plate and are located on the outer edge of the top plate.
The rib is a tabletop induction heating cooker located inside the heating plate. The tabletop induction heating cooker according to claim 1, wherein the heating plate projects from the lower surface of the heating plate toward the top plate side and has a positioning portion located on the outer edge of the top plate. The tabletop induction heating cooker according to claim 1 or 2, wherein the lower end of the rib is located below the upper surface of the top plate and above the lower surface of the top plate. One of claims 1 to 3, wherein the heating plate is capable of cooking across a plurality of heating regions heated by the plurality of heat generating portions, and has a partition portion for partitioning the plurality of heating regions. One of the tabletop induction heating cookers listed below. The tabletop according to claim 4, wherein the partition portion is a recess provided on the upper surface of the heating plate along a center line extending in the width direction of the heating plate when viewed from the thickness direction of the heating plate. Mold induction heating cooker. The side surface of the heating plate is composed of a surface inclined inward toward the top.
The tabletop induction heating cooker according to any one of claims 1 to 5.

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