JP5456001B2 - Induction heating cooker - Google Patents

Description

  The present invention relates to an induction heating cooker.

  As a conventional induction heating cooker, “a central coil wound in a planar shape, a plurality of peripheral coils arranged around the central coil, and a high frequency independently for each of the central coil and the peripheral coil. A plurality of power supply circuit units for supplying current; a detecting means for detecting a state in which the heated body is placed above the central coil and the peripheral coils; and the heated body detected by the detecting means And a drive control unit that controls the power supply circuit unit so that a high-frequency current is selectively supplied to each of the central coil and the peripheral coil according to the mounting state has been proposed ( For example, see Patent Document 1).

WO 2010/101202 (page 3 to page 7, FIG. 3)

  According to the induction heating cooker described in Patent Document 1, pans having various sizes and shapes can be used, and even when the pan is arranged away from the center of the heating port, it can be efficiently heated. . In this way, in order to take advantage of the features of efficient heating while increasing the shape and size of the pot to be used and the degree of freedom of pot arrangement, it is necessary to detect the temperature of the pot and the position of the pot more accurately. It is done. In Patent Document 1, it is described that a change in impedance of a plurality of heating coils (a central coil and a plurality of peripheral coils) is detected to detect a heating coil on which an object to be heated such as a pan is placed. However, an erroneous determination may occur depending on the material of the object to be heated. For this reason, it has been desired to detect the placement position (pot shift) of the object to be heated more accurately.

  The present invention has been made to solve the above-described problems, and provides an induction heating cooker that can accurately detect the position of an object to be heated.

The cooking device according to the present invention includes a top plate on which an object to be heated is placed, a heating port formed on the top plate and indicating a placement position of the object to be heated, and the heating port corresponding to the heating port. A heating coil group that is arranged below the top plate and configured by a plurality of heating coils, a drive unit that supplies a high-frequency current to each of the plurality of heating coils, and the top plate corresponding to the heating port Based on a plurality of temperature detection devices provided below and detection values of the plurality of temperature detection devices, a pan shift that is a state where the object to be heated is placed out of a predetermined region is determined. A pan deviation detecting unit and a control unit for controlling the driving unit are provided, and the pan deviation detecting unit reduces the value detected by the temperature detecting device as the magnetic field generated at the position of the temperature detecting device is stronger. a correction coefficient, wherein the driving state of each heating coil, each of said heating And positional relationship of said temperature sensing device relative yl, and set on the basis of a value detected by the plurality of temperature sensing devices, on the basis of said correction factor is to determine the pan displacement.

In the present invention, an object to be heated is preliminarily determined based on detection values by a plurality of temperature detection devices and a correction coefficient that decreases a value detected by the temperature detection device as a magnetic field generated at the position of the temperature detection device is stronger. A pan shift that is a state of being placed out of a predetermined area is determined. For this reason, the position of the pan can be detected with high accuracy.

It is a top view which shows the induction heating cooking appliance which concerns on Embodiment 1. FIG. It is a disassembled perspective view which shows the induction heating cooking appliance which concerns on Embodiment 1. FIG. It is a functional block diagram of the principal part of the induction heating cooking appliance which concerns on Embodiment 1. FIG. It is a figure explaining arrangement | positioning of the heating coil and temperature sensor of the induction heating cooking appliance which concerns on Embodiment 1. FIG. It is a figure explaining the judgment process of the pan deviation of the induction heating cooking appliance which concerns on Embodiment 1. FIG. It is a figure explaining the state of the magnetic field produced around the heating coil of the induction heating cooking appliance which concerns on Embodiment 1, and the heating distribution of a to-be-heated material. It is a flowchart explaining the heating operation of the induction heating cooking appliance which concerns on Embodiment 1. FIG. It is a figure explaining the mounting state of the to-be-heated material which concerns on Embodiment 1, and the drive state of a heating coil. It is a figure explaining the drive state of the heating coil which concerns on Embodiment 1, and its electric current direction. It is a figure which shows an example of the corresponding information of the drive state of the heating coil which concerns on Embodiment 1, and a correction coefficient. It is a figure explaining arrangement | positioning of the heating coil and temperature sensor of the induction heating cooking appliance which concerns on Embodiment 2. FIG.

Embodiment 1 FIG.
In this Embodiment 1, the case where this invention is applied to what is called a built-in type induction heating cooking appliance installed in the installation opening formed in kitchen furniture is demonstrated to an example.

[overall structure]
1 is a top view showing an induction heating cooker according to Embodiment 1. FIG.
FIG. 2 is an exploded perspective view showing the induction heating cooker according to the first embodiment.
In FIG. 1, FIG. 2 and each figure described later, the same reference numerals are the same or equivalent, and this is common throughout the entire specification.

  As shown in FIGS. 1 and 2, the induction heating cooker includes a main body 1 and a top plate 2 provided on the main body 1 and on which a heated object 9 such as a pan is placed. The induction heating cooker includes three heating ports, and includes heating units corresponding to each heating port: a first heating unit 3a, a second heating unit 3b, and a third heating unit 3c. The heated object 9 can be placed on the mouth and heated. In the first embodiment, the first heating unit 3 a and the second heating unit 3 b are provided side by side on the front side of the main body 1, and the third heating unit 3 c is provided at substantially the center on the back side of the main body 1.

  The top plate 2 is entirely made of a material that transmits infrared rays, such as heat-resistant tempered glass or crystallized glass, and is fixed in a watertight state between the outer periphery of the upper surface opening of the main body 1 via a rubber packing or a sealing material. Is done. The top plate 2 has a circular pan position display indicating a rough placement position of the pan corresponding to the heating range (heating port) of the first heating unit 3a, the second heating unit 3b, and the third heating unit 3c. It is formed by applying paint or printing.

  On the front side of the main body 1, as an input device for setting the heating power and cooking menu when heating the article 9 to be heated by the first heating unit 3a, the second heating unit 3b, and the third heating unit 3c, A unit 8a, an operation unit 8b, and an operation unit 8c (hereinafter may be collectively referred to as the operation unit 8) are provided. Further, in the vicinity of the operation unit 8, a display unit 7 a, a display unit 7 b, and a display unit 7 c (hereinafter collectively referred to as a display unit 7) that display the operation state of the induction heating cooker, the input / operation contents from the operation unit 8, and the like. May be provided).

  Below the top plate 2 and inside the main body 1, there are provided heating means respectively corresponding to the first heating unit 3a, the second heating unit 3b, and the third heating unit 3c. In this Embodiment 1, the heating means of the 1st heating part 3a, the 2nd heating part 3b, and the 3rd heating part 3c is comprised by the several induction heating coil. In addition, since all of these heating means are the same structures, in the following description, the heating means (heating coil) of the 1st heating part 3a is demonstrated to an example.

  The main body 1 includes a driving circuit 10 for supplying a high-frequency current to a heating coil as heating means of the first heating unit 3a, the second heating unit 3b, and the third heating unit 3c, and an induction heating including the driving circuit 10 A circuit unit 11 on which various control circuits for controlling the operation of the entire cooking device are mounted is provided.

At the rear of the upper surface of the main body 1, there are provided an intake port 17 that communicates with the inside of the main body 1 and takes cooling air into the main body 1 and an exhaust port 18 that discharges cooling air taken into the main body 1. ing. The air sucked into the main body 1 from the air inlet 17 cools various electrical components such as the drive circuit 10 and the circuit unit 11 inside the main body 1 and the heating coil, and then exhausts from the exhaust port 18 to the outside of the main body 1. Is done.
In addition, although the example which forms a ventilation hole in the back of the top plate 2 is shown in this Embodiment 1, the formation position of a ventilation hole is not limited to this, For example, in the back of the top plate 2 You may form a vent hole in the front surface and the back surface of the main body 1 without providing a vent hole.

FIG. 3 is a functional block diagram of a main part of the induction heating cooker according to the first embodiment.
The heating means of the first heating unit 3 a includes a central coil 4 disposed substantially at the center of the heating port, and a plurality of peripheral coils 5 disposed around the central coil 4. Examples of the shape and arrangement of the central coil 4 and the peripheral coil 5 will be described later. The center coil 4 and the peripheral coil 5 are held by a coil support (not shown).
In the following description, the central coil 4 and the peripheral coil 5 may be collectively referred to as “heating coil”.
The central coil 4 and the peripheral coil 5 provided corresponding to one heating port constitute a “heating coil group” in the present invention.

The drive circuit 10 is composed of an inverter circuit, and supplies a high frequency current to the central coil 4 and the peripheral coil 5. The drive circuit 10 is provided corresponding to each of the central coil 4 and the plurality of peripheral coils 5. That is, each heating coil constituting the heating means of the first heating unit 3a is independently driven by the drive circuit 10 corresponding thereto. In FIG. 3, the drive circuit 10 corresponding to each heating coil is illustrated separately as drive circuits a, b, and c.
The drive circuit 10 corresponds to a “drive unit” in the present invention.

  The drive control unit 12 controls the operation of the drive circuit 10 to control the input power (output) to the article 9 to be heated. The drive control unit 12 is configured to be able to individually control the plurality of drive circuits 10, and can supply a high-frequency current to each heating coil under an arbitrary drive condition.

The control unit 13 controls the drive control unit 12 based on a signal from the operation unit 8, a signal from the load detection unit 14, a detection value of the temperature sensor 20, and the like. Moreover, the control part 13 controls the operation | movement of the whole induction heating cooking appliance other than controlling the alerting | reporting part 16 and notifying a user.
In the first embodiment, the notification unit 16 includes the display unit 7, a buzzer (not shown), an audio output device, and the like. However, the notification unit 16 can notify the user visually or audibly information. If so, the specific configuration is not limited.

In addition, as will be described later, the control unit 13 determines a pan shift that is a state in which the article to be heated 9 is placed out of a predetermined region based on a detection value of the temperature sensor 20 or the like. is there. The operation for determining pan deviation will be described later.
The control unit 13 corresponds to a “pan shift detection unit” of the present invention.

The temperature sensor 20 is a contact-type temperature sensor or a non-contact-type temperature sensor, and detects the temperature of the object to be heated 9 placed on the top plate 2 or the top plate 2. When the temperature sensor 20 is a contact-type temperature sensor, the temperature sensor 20 is arranged so as to contact the lower surface of the top plate 2 and outputs a detection signal indicating the temperature of the top plate 2. When the temperature sensor 20 is a non-contact type temperature sensor, the temperature sensor 20 can capture heat radiation from the object 9 to be heated placed on the top plate 2 so as to capture the heat radiation of the top plate 2. The detection signal which is arrange | positioned below and shows the detected thermal radiation amount is output. In the first embodiment, a plurality of temperature sensors 20 are provided for the first heating unit 3a. In the following description, each of the temperature sensors 20a, 20b. . . In some cases, such a distinction is used. The arrangement of the temperature sensor 20 will be described later.
The temperature sensor 20 corresponds to a “temperature detection device” in the present invention.

  The temperature detection unit 21 is electrically connected to the temperature sensor 20, and based on the detection signal from the temperature sensor 20, the temperature of the top plate 2 or the heated object 9 placed on the top plate 2. Detect temperature. The temperature detection unit 21 outputs the detected temperature information to the control unit 13.

The load detection part 14 detects the mounting state of the article 9 to be heated above the central coil 4 and the plurality of peripheral coils 5 constituting the heating means of the first heating part 3a.
The load detection unit 14 corresponds to the “coil load detection unit” of the present invention.

  As a specific configuration of the load detection unit 14, for example, a current detection circuit for detecting the amount of current flowing through each of the central coil 4 and the peripheral coil 5 can be provided. In general, the impedance of the heating coil varies depending on the presence / absence, size (area), and material of the object 9 to be heated placed above the heating coil, and the inverter that constitutes the drive circuit 10 in accordance therewith. The amount of current flowing through the circuit also changes. Therefore, the impedance value of each heating coil is detected by detecting the amount of current flowing through the central coil 4 and the peripheral coil 5, thereby determining the placement state of the object 9 to be heated on each heating coil. In addition, the specific structure of the load detection part 14 is not limited to this.

  The detection result of the load detection unit 14 is output to the control unit 13. Based on the detection result of the load detection unit 14, the control unit 13 controls the drive control unit 12 to supply a high-frequency current to the heating coil on which the object to be heated 9 is placed, and the object to be heated The drive control unit 12 is controlled so as not to suppress or supply the high-frequency current to the heating coil on which 9 is not placed.

[Configuration of heating coil]
FIG. 4 is a diagram illustrating the arrangement of the heating coil and the temperature sensor of the induction heating cooker according to the first embodiment.
In FIG. 4, the central coil 4 has a circular planar shape, and is configured by winding a conductive wire made of an arbitrary metal with an insulating coating in the circumferential direction.
The central coil 4 includes an inner central coil 4a having a circular planar shape formed by winding conductive wires in the circumferential direction, and a conductive wire wound in the circumferential direction on the outer side in the radial direction than the inner central coil 4a. And an outer central coil 4b having an annular planar shape.
An annular gap is provided between the inner central coil 4a and the outer central coil 4b. The inner central coil 4a and the outer central coil 4b are connected in series and driven by a single drive circuit 10 (inverter circuit).
The inner central coil 4a and the outer central coil 4b may be driven in parallel. In this case, the inner central coil 4a and the outer central coil 4b can be driven using independent drive circuits (inverter circuits).

  The peripheral coil 5 is formed by winding a conductive wire made of an arbitrary metal with an insulating coating in an annular shape having a substantially arc-shaped planar shape. The substantially arc-shaped side of the peripheral coil 5 on the side close to the central coil 4 is substantially along the circular outer periphery of the central coil 4 at a predetermined interval, and a predetermined interval is provided between the central coil 4 and the peripheral coil 5. A long arc-shaped space is provided.

  In the first embodiment, four peripheral coils 5 (sometimes referred to as peripheral coils 5a, 5b, 5c, and 5d) are provided, and are substantially along the circular outer shape of the central coil 4, Arranged outside the central coil 4. Each peripheral coil 5 is arranged so as to be shifted by approximately 90 ° with respect to the central coil 4. The number of peripheral coils 5 is not limited to four.

The temperature sensor 20 is a line in which the circular outer shape of the central coil 4 and the 1/4 arc-shaped outer shape of the peripheral coil 5 are connected to the closest points, and the central coil 4 and the peripheral coil 5 Is arranged at a substantially intermediate position.
In addition, the number and arrangement position of the temperature sensor 20 are not limited to this.

In addition, when the heating means of one heating port is comprised by the central coil 4 which can be driven independently like this Embodiment 1, and the several peripheral coil 5 arrange | positioned in the periphery, each heating coil Is preferably located as close as possible. If the heating coils are too far apart, for example, heating unevenness may occur in the case of the large object 9 to be heated. For example, in the case of the small object 9 to be heated, there is a possibility that the heating object 9 may not be heated sufficiently depending on the mounting position. Because there is.
Moreover, it is preferable to arrange at least one of the plurality of temperature sensors 20 as close to the heating coil as possible. This is because if the temperature sensor 20 and the heating coil are too far apart, the temperature detection position and the heating position will be too far apart, and the temperature of the object to be heated cannot be detected accurately.

[Judgment judgment]
Next, an outline of the operation for determining the pan shift, which is a state in which the article 9 to be heated is placed out of a predetermined region, based on the detection value of the temperature sensor 20 as described above, will be described.

FIG. 5 is a diagram illustrating a process for determining pan misalignment of the induction heating cooker according to the first embodiment.
5 (a) and 5 (b) show different placement states of the object 9 to be heated, and FIG. 5 (a) shows a state in which the object 9 is placed out of a predetermined region. FIG. 5 (b) shows a state in which the object to be heated 9 is placed in a predetermined region and no pan deviation has occurred.
Further, the left side of the drawing shows the arrangement of the heating coil and the object 9 to be heated, and the right side of the drawing conceptually shows the change in heating time and the detected temperature of each temperature sensor 20.
In the present embodiment, an example will be described in which a state in which the object to be heated 9 deviates from a placement position that covers at least the entire surface of the central coil 4 is a pan shift state. In addition, the mounting position which judges a pan deviation state is not restricted to this.
In the following description, the heated object 9 is in a state where induction heating is started (initial heating stage) at the placement position of the heated object 9 shown in FIG. It is assumed that it has been moved to the position shown in FIG. Details of the heating operation will be described later.

In the mounting state shown in FIG. 5A, the object 9 to be heated is placed at a position off the center of the heating port, the temperature sensor 20b is covered by the object 9 to be heated, and the temperature sensors 20a, 20c , 20d is a state not covered by the article 9 to be heated.
In this case, the temperature detected by the temperature sensor 20b covered with the article 9 to be heated increases as the heating time elapses. On the other hand, the detected temperatures of the temperature sensors 20a, 20c, and 20d that are not covered by the article 9 to be heated rise by heat transfer through the top plate 2, but are lower than the detected temperatures of the temperature sensor 20b. Become. Further, the temperature detected by the temperature sensor 20d that is far from the object 9 to be heated is the lowest value.
As described above, the temperature detected by the temperature sensor 20 differs depending on the positional relationship between the object to be heated 9 and the temperature sensor 20, and therefore, based on the difference between the maximum value Tmax and the minimum value Tmin of the temperature detection value by each temperature sensor 20. A pan shift (pan position) of the heated object 9 can be determined.

In the mounting state shown in FIG. 5B, the object 9 to be heated is placed near the center of the heating port, and the temperature sensors 20a, 20b, 20c are covered with the object 9 to be heated. Reference numeral 20d denotes a state where the object to be heated 9 is not covered.
In this case, the detected temperatures of the temperature sensors 20a, 20b, and 20c covered with the article 9 to be heated increase with the elapse of the heating time, and become substantially the same value. Moreover, although the detection temperature of the temperature sensor 20d which is not covered with the to-be-heated object 9 is lower than the detection temperature of the other temperature sensor 20, since the distance with the to-be-heated object 9 is near, detection of the other temperature sensor 20 is carried out. It is close to temperature.
As described above, since the difference between the maximum value Tmax and the minimum value Tmin of the temperature detection value by each temperature sensor 20 is small, it can be determined that the pan shift of the article 9 to be heated has not occurred.

[Heating distribution]
Next, the distribution of the magnetic field generated around the heating coil and the heating distribution of the article 9 to be heated that is induction-heated by the magnetic field will be described.

  In each heating coil (the central coil 4 and each peripheral coil 5), the current flowing through the winding is controlled by the corresponding drive circuit 10. Depending on the phase of the high-frequency current flowing in each heating coil, there are cases where currents in the same direction flow in windings close to each other and currents in opposite directions flow in windings close to each other. Depending on the direction of the current flowing through the plurality of heating coils, there are portions where the magnetic fields generated around these portions strengthen and weaken, and the magnetic field distribution intersecting the object to be heated 9 may not be uniform. Due to such a magnetic field distribution, the amount of heating of the article 9 to be heated differs depending on the position, and the heating distribution of the article 9 to be heated may not be uniform.

Here, the state of the magnetic field generated around the heating coil and the heating distribution of the article 9 to be heated will be described by taking the central coil 4 and the peripheral coils 5b and 5d as examples.
FIG. 6 is a diagram illustrating a state of a magnetic field generated around a heating coil of the induction heating cooker according to Embodiment 1 and a heating distribution of an object to be heated. Further, the upper part of FIG. 6 conceptually shows the state of the magnetic field H generated around the heating coil, and the lower part of FIG. 6 shows the heating distribution of the object 9 to be heated that has been induction-heated by the magnetic field.

  In the example of FIG. 6, the central coil 4 and the peripheral coil 5 b are current-controlled in the same phase by the corresponding drive circuits 10, and currents in opposite directions flow through the windings adjacent to each other. In this case, as indicated by symbol P1, a current flows through the winding adjacent to the peripheral coil 5b of the central coil 4 from the front to the back of the page, and as indicated by symbol Q1, the peripheral coil 5b A current flows through the winding adjacent to the center coil 4 in the direction from the back to the front. As a result, the magnetic field H is generated in the same direction as indicated by the arrows P2 and Q2, and the magnetic field distribution is strengthened at the portion where the central coil 4 and the peripheral coil 5b are close to each other.

  As described above, since the region between the central coil 4 and the peripheral coil 5b is a portion where the magnetic field is relatively strong, the object to be heated 9 is easily induction-heated above the region. That is, in the region between the central coil 4 and the peripheral coil 5b, the amount of heating of the object 9 is relatively large (heating is large), and the temperature of the object 9 in the region is relatively high. . And the temperature sensor 20b is arrange | positioned between the center coil 4 and the peripheral coil 5b, ie, the range where a magnetic field strengthens, and the detected value becomes relatively high.

  In the example of FIG. 6, the central coil 4 and the peripheral coil 5d are current-controlled in opposite phases by the corresponding drive circuits 10, and currents in the same direction flow through the windings adjacent to each other. In this case, as indicated by symbol R1, a current flows through the winding adjacent to the peripheral coil 5d of the central coil 4 in the direction from the back to the front of the paper, and as indicated by symbol S1, the peripheral coil 5d A current flows through the winding adjacent to the center coil 4 in the direction from the back to the front. As a result, the magnetic field H is generated in the directions indicated by the arrows R2 and S2, and the magnetic field H generated from each other cancels out at a portion where the central coil 4 and the peripheral coil 5d are close to each other, thereby weakening the magnetic field distribution.

  As described above, since the region between the central coil 4 and the peripheral coil 5d is a portion where the magnetic field is relatively weak, the object to be heated 9 is difficult to be induction-heated above the region. That is, in the region between the central coil 4 and the peripheral coil 5d, the amount of heating of the object 9 is relatively small (heating is small), and the temperature of the object 9 in the region is relatively low. . The temperature sensor 20d is disposed between the central coil 4 and the peripheral coil 5d, that is, in a range where the magnetic fields cancel each other, and the detected value becomes relatively low.

  In addition, although the area | region between the center coil 4 and the peripheral coil 5 was demonstrated here, magnetic field distribution arises similarly about the area | region between the adjacent peripheral coils 5 according to the direction of the electric current which flows into a winding. .

As described above, in the induction heating of the object 9 to be heated, the heating amount is not uniform depending on the driving state of each heating coil, and a high portion and a low portion are generated in the heating distribution. A temperature distribution also occurs in the temperature of the object 9.
As described above, the pan shift is determined based on the temperature detection value of each temperature sensor 20. For this reason, when the above temperature distribution arises, a temperature difference will arise between the several temperature sensors 20 covered with the to-be-heated material 9. FIG.
That is, even if the pan of the article 9 to be heated does not occur, the difference between the maximum value Tmax and the minimum value Tmin of the temperature detection value becomes large depending on the driving state of the heating coil and the position of the temperature sensor 20. , It may be judged as a pot slip. Even if a pan shift occurs, the difference between the maximum value Tmax and the minimum value Tmin of the temperature detection value becomes small depending on the driving state of the heating coil and the position of the temperature sensor 20, and it is determined that the pan has shifted. May not be.

  For this reason, in the present embodiment, by using a correction coefficient that decreases as the heating amount of the heated object 9 at the arrangement position of the temperature sensor 20 increases, the heated object regardless of the heating distribution. Judge the pan of the object 9 accurately.

[Heating operation]
Next, the details of the heating operation of the induction heating cooker according to Embodiment 1 and the determination of pan deviation will be described.
FIG. 7 is a flowchart illustrating the heating operation of the induction heating cooker according to the first embodiment.
When the user places the object to be heated 9 on the top plate 2, sets the heating power to cook with the desired heating power by the operation unit 8, and presses the switch for starting heating, the control unit 13 The information regarding the heating power setting and the heating start instruction signal are received from the unit 8 (S1).

When receiving the heating start instruction signal, the control unit 13 detects the placement state of the article 9 to be heated above each heating coil by using the load detection unit 14 (S2). Specifically, for example, the drive control unit 12 is controlled so that a weak current (pan determination current) flows through each heating coil, and the drive circuit 10 supplies a high-frequency current to each heating coil. And based on the electric current value which flows into each heating coil detected by the load detection part 14, the mounting state of the to-be-heated material 9 on each heating coil is detected. In the following description, the heating coil with the heated object 9 placed thereon is referred to as a “heating coil with load”, and the heating coil without the heated article 9 placed thereon is referred to as “unloaded heating coil”. Sometimes called.
In addition, you may make it detect the state by which the to-be-heated material 9 is mounted in a part on a heating coil. For example, when the article 9 to be heated is placed in a range of approximately half or more above the heating coil, the mounting state on the heating coil is detected, and in a range less than approximately half above the heating coil. When the article 9 to be heated is placed, a part of the placement state on the heating coil is detected. In the following description, the heating coil in which the article 9 to be heated is placed on a part of the heating coil may be referred to as a “heating coil with a partial load”.

The control part 13 which detected the mounting state of the to-be-heated object 9 on a heating coil controls the drive control part 12 so that a high frequency current may be supplied to a heating coil with a load (S3). At this time, the control unit 13 controls the drive circuit 10 via the drive control unit 12 so that the heating power (input power) set by the operation unit 8 is obtained. In this heating control, the control unit 13 determines the temperature of the article 9 to be heated based on the temperature detected by the temperature sensor 20 and controls the drive control unit 12 so that the heating state set by the operation unit 8 is achieved. To do.
Note that the drive control unit 12 may be controlled so that a high-frequency current is supplied also to the heating coil with a partial load. At this time, the heating power (input power) set for the heating coil with partial load may be made smaller than that of the heating coil with load.
Here, a specific example of the placement position of the article 9 to be heated and the driving state of the heating coil will be described with reference to FIG.

FIG. 8 is a diagram for explaining the placement position of the object to be heated and the driving state of the heating coil according to the first embodiment.
As shown in FIG. 8, the elliptical object 9 is placed on the entire surface of the central coil 4 and the peripheral coils 5b and 5d, and is placed on a part of the peripheral coils 5a and 5c (less than half range). When placed, the control unit 13 does not supply high frequency current to the peripheral coils 5a and 5c that are unloaded coils, and supplies high frequency current to the central coil 4 and the peripheral coils 5a and 5d that are heated coils. Then, the drive control unit 12 is controlled so that the set thermal power (input power) is obtained.
Thus, according to the shape of the to-be-heated object 9, such as a small pot, an elliptical pot, and a square pot, by driving according to the state of the to-be-heated object 9 placed above the heating coil. And can be heated efficiently.

Returning to the description of FIG.
The control unit 13 determines a correction coefficient for each temperature sensor 20 based on the driving state (driving mode, heating power, etc.) of each heating coil and the arrangement relationship of the temperature sensors 20 (S4).
The determination of the correction coefficient can be determined by, for example, storing in advance information on the driving state of each heating coil and the corresponding correction coefficient of each temperature sensor 20 and referring to the information. An example will be described with reference to FIGS.

FIG. 9 is a diagram for explaining a driving state and a current direction of the heating coil according to the first embodiment.
Here, an elliptical object to be heated 9 as shown in FIG. 8 is placed, high frequency current is not supplied to the peripheral coils 5a and 5c, and high frequency current is supplied to the central coil 4 and the peripheral coils 5b and 5d. The case where it does is demonstrated.
As shown in FIG. 9A, the driving mode in which the currents flowing through the central coil 4 and the peripheral coils 5b and 5d are controlled in the same phase and reverse current flows through the windings close to each other is referred to as case 1. That is, in case 1, the direction of current at a certain moment is the same direction (current direction A).
As shown in FIG. 9B, the currents flowing through the central coil 4 and the peripheral coil 5b are controlled in reverse phase, and the currents flowing through the central coil 4 and the peripheral coil 5d are also controlled in reverse phase. A driving mode in which a directional current flows is referred to as Case 2. That is, in case 2, the current direction at a certain moment is the same direction (current direction A) for the peripheral coil 5b and the peripheral coil 5d, and the reverse direction (current direction B) for the central coil 4.
As shown in FIG. 9C, the currents flowing through the central coil 4 and the peripheral coil 5b are controlled in opposite phases, and currents in the same direction flow through the windings adjacent to each other in the central coil 4 and the peripheral coil 5b. Case 3 is a drive mode in which currents flowing through the coil 4 and the peripheral coil 5d are controlled to have the same phase, and currents in opposite directions flow through windings of the central coil 4 and the peripheral coil 5d that are close to each other. That is, in case 3, the current direction at a certain moment is the same direction (current direction B) for the central coil 4 and the peripheral coil 5d, and the reverse direction (current direction A) for the peripheral coil 5b.

FIG. 10 is a diagram illustrating an example of correspondence information between the driving state of the heating coil and the correction coefficient according to the first embodiment.
The upper part of FIG. 10 shows an example of the temperature sensor 20 (TH) and its correction coefficient according to each case of the drive mode and the thermal power.
The lower part of FIG. 10 shows the position of the temperature sensor 20 in each case and the magnitude of the heating amount (heat generation amount) of the article 9 to be heated.

In FIG. 10, the coil 1 corresponds to the peripheral coil 5b, the coil 2 corresponds to the central coil 4, and the coil 3 corresponds to the peripheral coil 5d. TH1 corresponds to the temperature sensor 20b disposed between the coil 1 and the coil 2, and TH2 corresponds to the temperature sensor 20d disposed between the coil 2 and the coil 3. TH3 corresponds to the temperature sensor 20a disposed between the coil 2 and the stopped heating coil (peripheral coil 5a), and TH4 is between the coil 2 and the stopped heating coil (peripheral coil 5c). It corresponds to the arranged temperature sensor 20c.
Thus, the correspondence information set in advance can be generalized by making the coils and TH in the correspondence information correspond to the heating coils and the temperature sensor 20. For example, in the driving mode in which the central coil 4 and the peripheral coils 5a and 5c are driven and the peripheral coils 5b and 5d are stopped, the coil and TH may be associated with each other using the same correspondence information.

In case 1, the region between the coil 1 and the coil 2 and the region between the coil 2 and the coil 3 are both regions that strengthen the magnetic field. For this reason, the amount of heating of the object 9 to be heated at the arrangement positions of TH1 and TH2 is increased, and the temperature detection values by TH1 and TH2 are relatively higher than the detection values by TH3 and TH4. For this reason, the correction coefficients for TH1 and TH2 are set smaller than those for TH3 and TH4.
That is, the correction coefficient of the temperature sensor 20 disposed between the central coil 4 and the peripheral coil 5 in which current flows in the opposite direction in the adjacent portion, the peripheral coil 5 and the central coil 4 that are not supplied with high-frequency current. Is set smaller than the correction coefficient of the temperature sensor 20 disposed between the two.
Further, the larger the set thermal power, the larger the correction coefficient value is set.

In case 2, the region between coil 1 and coil 2 and the region between coil 2 and coil 3 are both regions that cancel out the magnetic field. For this reason, the heating amount of the object 9 to be heated at the positions where TH1 and TH2 are arranged becomes small, and the temperature detection values by TH1 and TH2 are relatively lower than the detection values by TH3 and TH4. For this reason, the correction coefficients for TH1 and TH2 are set larger than those for TH3 and TH4.
That is, the correction coefficient of the temperature sensor 20 disposed between the central coil 4 and the peripheral coil 5 in which current flows in the same direction in the adjacent portions is set to the peripheral coil 5 and the central coil 4 in which the supply of high-frequency current is stopped. Is set larger than the correction coefficient of the temperature sensor 20 arranged between the two.
Further, the larger the set thermal power, the larger the correction coefficient value is set.

In case 3, the region between the coil 1 and the coil 2 is a region that cancels out the magnetic field, and the region between the coil 2 and the coil 3 is a region that strengthens the magnetic field.
For this reason, the amount of heating of the article 9 to be heated at the position where TH1 is disposed is small, and the temperature detection value by TH1 is relatively lower than the detection values by TH3 and TH4. For this reason, the correction coefficient of TH1 is set larger than TH3 and TH4.
In addition, the amount of heating of the object 9 to be heated at the position where TH2 is disposed increases, and the temperature detection value by TH2 is relatively higher than the detection values by TH3 and TH4. For this reason, the correction coefficient of TH2 is set smaller than TH3 and TH4.
That is, the correction coefficient of the temperature sensor 20 disposed between the central coil 4 and the peripheral coil 5 in which current flows in the same direction in the adjacent portion is set to the central coil 4 and the peripheral coil in which current flows in the reverse direction in the adjacent portion. 5 is set larger than the correction coefficient of the temperature sensor 20 arranged between the temperature sensor 20 and the temperature sensor 20 arranged between the peripheral coil 5 and the central coil 4 where the supply of the high-frequency current is stopped.
In addition, the correction coefficient of the temperature sensor 20 arranged between the central coil 4 and the peripheral coil 5 in which current flows in the opposite direction in the adjacent portion is the same as the central coil 4 and the peripheral coil in which current flows in the same direction in the adjacent portion. 5 is set smaller than the correction coefficient of the temperature sensor 20 disposed between the temperature sensor 20 and the temperature sensor 20 disposed between the peripheral coil 5 and the central coil 4 in which the supply of the high-frequency current is stopped.
Further, the larger the set thermal power, the larger the correction coefficient value is set.

In addition, the value of the correction coefficient in FIG. 10 is an example, and is not limited to this.
In the example of FIG. 10, three cases have been described as drive modes, but the present invention is not limited to this. A correction coefficient corresponding to an arbitrary driving condition that affects the heating distribution of the article 9 to be heated can be set as appropriate. For example, the higher the drive frequency, the greater the amount of heating to the article 9 to be heated. Therefore, the correction coefficient may be set according to the drive frequency of each heating coil.
In the example of FIG. 10, the case where three heating coils are driven has been described. However, the present invention is not limited to this. The same type of correspondence information may be stored in advance according to the number of heating coils to be driven and the arrangement relationship thereof.
Moreover, although the case where the temperature sensor 20 is arrange | positioned between the center coil 4 and the peripheral coil 5 is demonstrated in this Embodiment, the arrangement position of the temperature sensor 20 is not limited to this. For example, it may be disposed between adjacent peripheral coils 5, or may be disposed inside the central coil 4 and the peripheral coil 5. Also in this case, similarly, the correction coefficient is set according to the heating distribution of the article 9 to be heated at the position where the temperature sensor 20 is disposed.

Returning to the description of FIG.
The control part 13 acquires the temperature detection value by each temperature sensor 20 from the temperature detection part 21, respectively, and correct | amends each temperature detection value of each temperature sensor 20 using the determined correction coefficient (S5). For example, correction is performed by multiplying the temperature detection value of the temperature sensor 20 by a correction coefficient.
By such correction, the temperature detection value at the location where the heating distribution of the article 9 is high is corrected small, and the temperature detection value at the location where the heating distribution is low is corrected largely.

  Next, the control unit 13 acquires a maximum value Tmax and a minimum value Tmin from the corrected temperature detection values (S6). Then, the control unit 13 determines pan deviation (pan position) by determining whether or not the difference between the maximum value Tmax and the minimum value Tmin exceeds a predetermined threshold A (for example, 50 ° C.). (S7).

  Thereby, even if it is a case where the location with a high heating distribution and the location where a heating distribution is low arises in the to-be-heated material 9, the temperature difference between the several temperature sensors 20 covered with the to-be-heated material 9 can be decreased. it can. For this reason, when the pan shift of the article 9 to be heated does not occur, the difference between the maximum value Tmax and the minimum value Tmin does not increase, and it is not erroneously determined that the pan shift. Moreover, when the pan deviation has occurred, the difference between the maximum value Tmax and the minimum value Tmin does not become small, and it can be determined that the pan has shifted. Thus, by using the temperature detection value corrected by the correction coefficient, it is possible to accurately determine the pan shift of the article 9 to be heated.

  In the present embodiment, the load detector 14 detects the placement state of the object 9 to be heated on the heating coil. However, the temperature of the object 9 to be heated is more accurately determined by the temperature detected by the temperature sensor 20. The position can be detected.

  When the condition of step S7 is not satisfied, that is, when it is determined that no pan shift has occurred (S7; No), the control unit 13 returns to step S2 and continues the control for obtaining the set thermal power. To do.

  On the other hand, when satisfy | filling the conditions of step S7, ie, when it is judged that the pan deviation has arisen (S7; Yes), the control part 13 uses the fact that the pan has shifted by controlling the alerting | reporting part 16. (S8). For notification, a lamp may be turned on or a warning message may be displayed on the display unit 7, or instead of or in addition to this, sound may be output by a buzzer or a speaker (not shown). By doing in this way, it can be made to recognize that the user has pan-shifted.

After notifying that the pan shift has occurred in step S8, the control unit 13 obtains the temperature detection value by each temperature sensor 20 again, and from among the temperature detection values corrected using the correction coefficient. The maximum value Tmax and the minimum value Tmin are acquired (S9).
Then, the control unit 13 determines whether or not the difference between the maximum value Tmax and the minimum value Tmin exceeds a predetermined threshold A (S10). Here, it is determined again whether or not the user has solved the pan deviation by notification.

  And when not satisfy | filling the conditions of step S10, ie, when pan deviation is eliminated (S10; No), the control part 13 returns to step S2, and continues control for obtaining the set thermal power. .

On the other hand, when the condition of step S10 is satisfied, that is, when the pan shift state continues (S10; Yes), whether the predetermined time α has elapsed since the control unit 13 performed the notification in step S8. It is determined whether or not (S11).
Before the elapse of the predetermined time α (S11; No), the control unit 13 returns to step S9 and repeats the above-described operation to determine the pan deviation.
When the predetermined time α has elapsed (S11; Yes), the control unit 13 controls the drive control unit 12 to limit the heating power set by the operation unit 8 (S12). By doing in this way, the excessive temperature rise of the to-be-heated material 9 and a heating coil in the case where the pan-shift state has arisen can be suppressed.

  Next, an application example of the heating operation of the induction heating cooker shown in FIG. 7 will be described.

(Application example of step S6)
The temperature sensor 20 that refers to the detected temperature when determining pan deviation may be selected based on the load detection result in step S2. For example, among the plurality of temperature sensors 20, the detected temperature of the temperature sensor 20 in the vicinity of the heating coil determined to be a no-load heating coil in step S2 is not referred to. As described above, by selecting the temperature sensor 20 to be referred to based on whether or not the object to be heated 9 is placed on the heating coil, it is possible to reduce the error in determining the pan deviation.

(Application example of step S7)
The threshold value for determining the difference between the maximum value Tmax and the minimum value Tmin of the detected value of the temperature sensor 20 may be a different value based on the load detection result in step S2. For example, when the temperature sensor 20 that detects the minimum value Tmin is in the vicinity of the heating coil without load, the threshold value used for determining the pan deviation is set to be higher than that in the vicinity of the heating coil with load. A large value is assumed. The first embodiment is characterized in that the central coil 4 and the plurality of peripheral coils 5 can be driven independently. For example, even when there are one or more unloaded heating coils, efficient cooking can be performed. One.
When heating is performed in this state, the temperature detected by the temperature sensor 20 in the vicinity of the no-load heating coil can hardly be expected to rise. Regardless of pan misregistration, the feature of the heating part of the first embodiment that the degree of freedom of the shape, size, and placement position of the article 9 to be heated cannot be fully utilized. It can lead to bitterness.
For this reason, when referring to the detection value of the temperature sensor 20 in the vicinity of the heating coil without load, by setting the threshold value to a large value, while taking advantage of the feature that the degree of freedom of the heated object 9 is high, Judgment of pan misalignment can also be made.

(Application example of step S12)
(1) Operation example of thermal power limitation When thermal power limitation is performed, the input power may be reduced or stopped for all of the heating coils being driven. By doing in this way, the rapid temperature rise of the to-be-heated object 9 or the whole heating coil can be suppressed.
Moreover, you may selectively reduce or stop the input electric power to the heating coil arrange | positioned in the vicinity of the temperature sensor 20 which detected minimum value Tmin among the some peripheral coils 5. FIG. In addition, the input power to the heating coil arranged in the direction of the temperature sensor 20 that detects the minimum value Tmin (the direction with the center of the heating coil as a reference) may be selectively reduced or stopped.
That is, based on the temperature detected by the temperature sensor 20, a heating coil that is not likely to be heated or has a small mounting area is determined, and the input power is selectively reduced for the heating coil. Or stop it.
By doing in this way, the useless electric power which does not contribute to the heating of the to-be-heated material 9 can be reduced, and the excessive temperature rise of a heating coil can be suppressed.

(2) Operation Before Limiting Thermal Power Before performing thermal power limitation with detection of a pan shift, the notification unit 16 may notify that thermal power limitation is to be performed. By doing in this way, the user can be urged to eliminate the pan shift. Then, after notifying that the heating power is limited, the difference between the maximum value Tmax and the minimum value Tmin of the detected value of the temperature sensor 20 is compared with the threshold value A, and the difference is below the threshold value A. Then, the notification by the notification unit 16 is stopped and the thermal power restriction is not performed. If the pan shift is eliminated, the heating power is not restricted, so that it is possible to provide an easy-to-use induction heating cooker without impairing the cooking feeling for the user. Even after the notification that the thermal power limitation is performed, the thermal power limitation is performed when the difference between the maximum value Tmax and the minimum value Tmin is larger than the threshold value.

(Application examples of steps S8 to S12)
In FIG. 7, when the pan shift is detected in step S <b> 7, it is assumed that the heating power is limited after a predetermined time α has elapsed after notifying the pan shift in step S <b> 8. However, the control part 13 is good also as performing the alert | report of pan deviation and a thermal-power restriction | limiting simultaneously, when a pan deviation is detected in step S7. By doing in this way, a thermal power restriction can be performed earlier and an excessive temperature rise of the article 9 and the heating coil can be suppressed.

As described above, in the present embodiment, the control unit 13 (pan deviation detection unit) increases the detection value by the plurality of temperature sensors 20 and the amount of heating of the article 9 to be heated at the position where the temperature sensors 20 are disposed. Based on the correction coefficient that decreases the value, the pan shift that is the state in which the article to be heated 9 is placed out of the predetermined region is determined.
For this reason, even if it is a case where a high location and a low location arise in the heating distribution of the to-be-heated material 9, the pan shift of the to-be-heated material 9 can be determined accurately. Therefore, the position of the article 9 to be heated can be detected with high accuracy.

In the present embodiment, the correction coefficient is set based on the driving state of each heating coil and the arrangement relationship of the temperature sensor 20 with respect to each heating coil.
For this reason, the temperature detection value in the location where the heating distribution of the object 9 is high is relatively small, and the temperature detection value in the location where the heating distribution is low can be relatively large. Even in the case where a high part and a low part occur in the distribution, the temperature difference between the plurality of temperature sensors 20 covered with the article 9 to be heated can be reduced. Therefore, by using the temperature detection value corrected by the correction coefficient, it is possible to accurately determine the pan shift of the object 9 to be heated.

In the present embodiment, the temperature sensor 20 is disposed between adjacent heating coils. And the control part 13 (pan shift | offset | difference detection part) is a heating coil in which an electric current flows in the same direction in the adjacent part as the correction coefficient of the temperature sensor 20 arrange | positioned between the heating coils in which an electric current flows in the reverse direction in an adjacent part. It is set smaller than the correction coefficient of the temperature sensor 20 disposed between them.
For this reason, the detection value of the temperature sensor 20 that is arranged in a region where the magnetic field is strengthened and the detected temperature is relatively large is detected by the temperature sensor 20 that is arranged in the region where the magnetic field is weakened and the detected temperature is relatively small. The temperature difference between the plurality of temperature sensors 20 covered by the object to be heated 9 can be reduced even if the heating distribution of the object to be heated 9 can be corrected to be smaller than the value and even if there are high places and low places. can do. Therefore, the pan shift of the article 9 to be heated can be accurately determined.

Further, in the present embodiment, the control unit 13 (pan deviation detecting unit) stops supplying the high-frequency current to the correction coefficient of the temperature sensor 20 disposed between the heating coils in which the current flows in the opposite direction in the adjacent portions. The heating coefficient and the high-frequency current are set smaller than the correction coefficient of the temperature sensor 20 disposed between the heating coil being supplied.
For this reason, it is possible to correct the detection value of the temperature sensor 20 which is arranged in a region where the magnetic field is strengthened and the detection temperature is relatively large, to be smaller than the detection value of the temperature sensor 20 where the detection temperature is relatively small. Even in the case where a high portion and a low portion are generated in the heating distribution 9, the temperature difference among the plurality of temperature sensors 20 covered with the article 9 to be heated can be reduced. Therefore, the pan shift of the article 9 to be heated can be accurately determined.

Embodiment 2. FIG.
In the second embodiment, another arrangement example of the heating coil and the temperature sensor will be described.
In the second embodiment, the difference from the first embodiment will be mainly described.

FIG. 11 is a diagram for explaining the arrangement of the heating coil and the temperature sensor of the induction heating cooker according to the second embodiment.
The central coil 4 and the peripheral coil 5 in the second embodiment have a circular planar shape, and are configured by winding a conductive wire made of any metal with an insulating coating in the circumferential direction. In the second embodiment, the diameter of the central coil 4 is larger than that of the peripheral coil 5 and the number of turns of the conductive wire is larger, but the present invention is not limited to this.

  In the second embodiment, six peripheral coils 5 (may be referred to as peripheral coils 5a, 5b, 5c, 5d, 5e, and 5f in some cases) are provided. The peripheral coils 5 are arranged at substantially equal intervals on the outer peripheral side of the central coil 4 so as to be substantially along a circle. The number and arrangement of the peripheral coils 5 are not limited to those shown in the drawing.

The temperature sensors 20 a to 20 f in the second embodiment are arranged between the central coil 4 and the peripheral coil 5. For example, on the line connecting the center of the central coil 4 and the center of the peripheral coil 5, the central coil 4 and the peripheral coil 5 are arranged at a substantially intermediate position.
In addition, the number and arrangement position of the temperature sensor 20 are not limited to this.

  Even in such a configuration, similarly to the first embodiment, the correction coefficient is set based on the driving relationship of each heating coil and the arrangement relationship of the temperature sensor 20, and the pan deviation determination is performed, and thus the first embodiment will be described. Effects can be obtained.

In the first and second embodiments, the configuration in which the central coil 4 and the peripheral coil 5 are arranged around the central coil 4 is described as the configuration of the heating coil group corresponding to the heating port. However, the present invention is not limited to this. Absent. For example, a plurality of heating coils having different diameters may be arranged concentrically.
Moreover, in the said description, the heating means in any one of the 1st heating part 3a, the 2nd heating part 3b, and the 3rd heating part 3c is an electric heater (for example, a nichrome wire, a halogen heater, etc.) heated by radiation, for example. (Radiant heater) may be used.

  DESCRIPTION OF SYMBOLS 1 Main body, 2 Top plate, 3a 1st heating part, 3b 2nd heating part, 3c 3rd heating part, 4 center coil, 4a inner center coil, 4b outer center coil, 5 peripheral coil, 7 display part, 8 operation part , 9 Object to be heated, 10 Drive circuit, 11 Circuit unit, 12 Drive control unit, 13 Control unit, 14 Load detection unit, 16 Notification unit, 17 Inlet port, 18 Exhaust port, 20 Temperature sensor, 21 Temperature detection unit.

Claims (15)

A top plate on which the object to be heated is placed;
A heating port formed on the top plate and indicating a placement position of the object to be heated;
A heating coil group that is arranged below the top plate corresponding to the heating port, and is composed of a plurality of heating coils,
A drive unit for supplying a high-frequency current to each of the plurality of heating coils;
A plurality of temperature detectors provided below the top plate corresponding to the heating port;
Based on the detection values of the plurality of temperature detection devices, a pan shift detection unit that determines pan shift that is a state where the object to be heated is placed out of a predetermined region;
A control unit for controlling the drive unit,
The pan displacement detector
The correction coefficient that decreases the value detected by the temperature detection device as the magnetic field generated at the position of the temperature detection device becomes stronger, the driving state of each heating coil, and the arrangement relationship of the temperature detection device with respect to each heating coil and, to set on the basis of,
An induction heating cooker, wherein the pan shift is determined based on detection values obtained by the plurality of temperature detection devices and the correction coefficient. A coil load detection unit for detecting the placement state of the object to be heated on each heating coil;
The controller is
The induction heating cooker according to claim 1, wherein a high-frequency current supplied to the plurality of heating coils is varied based on a placement position of the object to be heated detected by the coil load detection unit. The pan displacement detector
When the difference between the maximum value and the minimum value of the detected values of the plurality of temperature detection devices corrected using the correction coefficient exceeds a predetermined threshold value, the pan shift is determined. Item 3. The induction heating cooker according to item 1 or 2. The temperature sensing device is disposed between the adjacent heating coils,
The pan displacement detector
The correction coefficient of the temperature detection device arranged between the heating coils in which current flows in the opposite direction in adjacent portions,
The induction according to any one of claims 1 to 3, wherein the induction coefficient is set smaller than the correction coefficient of the temperature detection device arranged between the heating coils in which current flows in the same direction in adjacent portions. Cooking cooker. The pan displacement detector
The correction coefficient of the temperature detection device arranged between the heating coils in which current flows in the opposite direction in adjacent portions,
5. The correction coefficient of the temperature detection device disposed between the heating coil in which the supply of the high-frequency current is stopped and the heating coil in which the high-frequency current is being supplied is set smaller than the correction coefficient. Induction heating cooker. The controller is
According to the set thermal power, the drive unit is controlled to vary the high-frequency current supplied to the plurality of heating coils,
The pan displacement detector
The induction heating cooker according to any one of claims 1 to 5, wherein the correction coefficient is set to a larger value as the set thermal power is larger. The controller is
When it is determined by the pan displacement detector that the pan is misaligned,
The induction heating cooker according to any one of claims 1 to 6, wherein the driving unit is controlled so as to reduce or stop the supply of high-frequency current to at least one of the plurality of heating coils. . The controller is
When it is determined that the pan shift is detected by the pan shift detector,
The drive unit is controlled to reduce or stop the supply of the high-frequency current to the heating coil arranged closest to the temperature detection device that has detected the minimum value among the plurality of temperature detection devices. The induction heating cooker according to claim 7. The pan displacement detector
Based on the detected value of the temperature detection device excluding the temperature detection device arranged closest to the heating coil, which is detected by the coil load detection unit that the object to be heated is not placed above, The induction cooking device according to any one of claims 2 to 8, which is dependent on claim 2 and claim 2, wherein the pan displacement is determined. The pan displacement detector
When the temperature detecting device arranged closest to the heating coil detected that the object to be heated is not placed on the upper side by the coil load detecting unit detects the minimum value, The induction heating cooker according to claim 9, wherein the pan shift is determined using a threshold value having a value larger than that when the temperature detection device detects the minimum value. 11. The apparatus according to claim 1, further comprising a notifying unit that notifies that a pan slip has occurred when the pan slip detecting unit determines that the pan slip has occurred. Induction heating cooker. The notification unit
The induction heating cooker according to claim 11, wherein a notification that the supply of the high-frequency current is reduced or stopped is performed before the supply of the high-frequency current to the heating coil is reduced or stopped. When the pan displacement detection unit determines that the pan displacement,
Announcement that a pan shift has occurred by the reporting unit,
The induction cooking device according to any one of claims 1 to 12, wherein after the notification, the pan displacement detection unit determines the pan displacement again. When the pan displacement detection unit determines that the pan displacement,
The control unit controls the driving unit so as to selectively reduce or stop the supply of high-frequency current to at least one of the plurality of heating coils,
The induction heating cooker according to any one of claims 1 to 13, wherein a notification that a pan shift has occurred is performed by a notification unit. The heating coil constituting the heating coil group includes a central coil and a plurality of peripheral coils arranged around the central coil. Induction heating cooker.

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