JP5323148B2 - Induction heating cooker - Google Patents

Description

  The present invention relates to an induction heating cooker.

  As a conventional technique, for example, an induction heating cooker has been proposed (for example, if the oscillation frequencies of a plurality of inverter circuits are the same, no interference sound is generated even if a plurality of inverter circuits are operated simultaneously) (for example, Patent Document 1).

  Further, for example, “... high frequency flowing in one of the heating coils when at least two heating coils of the plurality of heating coils are heating an object to be heated made of a low-resistance nonmagnetic metal. An induction heating apparatus that controls the difference between the frequency of the current and the frequency of the high-frequency current flowing in the other heating coil to be higher than the audible frequency has been proposed (for example, see Patent Document 2).

Japanese Patent Laid-Open No. 01-260785 (page 3) Japanese Patent Laying-Open No. 2005-149737 (Claim 1)

However, the technique of the above-mentioned patent document 1 makes the difference between the oscillation frequencies of the plurality of heating ports zero by performing input power control (heating power adjustment) of the plurality of heating ports based on a certain fixed oscillation frequency. Therefore, it is not intended to change the oscillation frequency.
For this reason, there existed a subject that sufficient electric power could not be supplied depending on the material of the pan which is a thing to be heated.

Moreover, the technique of the said patent document 2 is when one at least 2 heating coils among several heating coils are heating low resistance nonmagnetic metals, such as aluminum, to one heating coil among the said heating coils. Control is performed so that the frequency difference between the frequency of the flowing high-frequency current and the frequency of the high-frequency current flowing in the other heating coil is higher than the audible frequency.
For this reason, there has been a problem that the device is complicated and the cost is increased to increase the driving frequency.
In addition, when heating an object to be heated of magnetic metal such as iron or stainless steel at both of the heating ports, it operates at a lower frequency than low resistance nonmagnetic metal and supports both magnetic and nonmagnetic. Setting the frequency difference higher than the audible frequency increases the loss of the switching element of the coil drive circuit, and there are problems such as an increase in the size of the cooling device and a reduction in efficiency.

  The present invention has been made to solve the above-described problems, and induction heating cooking that can suppress the generation of interference sound when simultaneously driving a plurality of heating means corresponding to a plurality of heating ports. To get a vessel.

  An induction heating cooker according to the present invention includes a top plate on which an object to be heated is placed, a plurality of heating ports formed on the top plate and indicating a placement position of the object to be heated, and each heating port. A heating means for inductively heating the object to be heated placed on the heating port, a drive circuit for supplying high-frequency power to the heating means by an on / off operation of a switching element, and an input of an operation related to cooking And a control unit that controls the drive circuit based on an input from the operation unit, and among the plurality of heating ports, at least one heating port includes a plurality of corresponding heating means. Each of the drive circuits supplies high-frequency power to the heating coil, and the control unit is a heating port in which the heating unit is configured by a plurality of heating coils. A certain first In the case where the object to be heated placed on the heating port and the second heating port adjacent to the first heating port are simultaneously induction-heated, the heating of the first heating port is performed. The operating frequency of the drive circuit for driving a part of the heating coils including at least the heating coil closest to the second heating port among the plurality of heating coils constituting the means is set as the operating frequency of the first heating port. The operating frequency of the driving circuit that drives the other heating coil constituting the heating means and the driving circuit that drives the heating means of the second heating port is set higher than the audible frequency.

  In the present invention, when a plurality of heating means are induction-heated simultaneously, the generation of interference noise can be suppressed.

It is a figure which shows the induction heating cooking appliance which concerns on Embodiment 1 of this invention. It is a block diagram explaining the structure of the induction heating cooking appliance which concerns on Embodiment 1 of this invention. It is a figure explaining operation | movement of the induction heating cooking appliance which concerns on Embodiment 1 of this invention. It is a block diagram explaining the structure of the induction heating cooking appliance which concerns on Embodiment 2 of this invention. It is a figure which shows the case where the mounting direction of the elliptical to-be-heated material mounted in the 1st heating port is another. It is a block diagram explaining the structure of the induction heating cooking appliance which concerns on Embodiment 4 of this invention. It is a block diagram explaining the structure of the induction heating cooking appliance which concerns on Embodiment 5 of this invention. It is a figure which shows the induction heating cooking appliance which concerns on Embodiment 6 of this invention. It is a figure which shows the arrangement position of the heating coil of the induction heating cooking appliance which concerns on Embodiment 6 of this invention.

Embodiment 1 FIG.
1 is a diagram showing an induction heating cooker according to Embodiment 1 of the present invention.
In FIG. 1, an induction heating cooker body 1 has a top plate 2 on which an object to be heated 5 such as a pan is placed. On the top plate 2, three heating ports for indicating the placement position of the article to be heated 5 are provided.
In the present embodiment, of the three heating ports on the top plate 2, the heating port on the left side of the front will be referred to as the first heating port 3, and the heating port on the right side of the front will be described as the second heating port 4.
The number of heating ports is not limited to three, and two or more arbitrary heating ports may be provided.

On the top plate 2, an operation unit 7 for setting the heating power and the like for each heating port, and a display unit 8 for displaying the set heating power and the operating state are provided.
The operation unit 7 and the display unit 8 are not particularly limited, for example, when the operation unit 7 and the display unit 8 are provided for each heating port, or when the operation unit and the display unit are provided for each heating port.

FIG. 2 is a block diagram illustrating the configuration of the induction heating cooker according to Embodiment 1 of the present invention.
In addition, in FIG. 2, the part relevant to the 1st heating port 3 and the 2nd heating port 4 of the induction heating cooking appliance main body 1 is shown.
In FIG. 2, the first heating port 3 and the second heating port 4 on the top plate 2 are each provided with heating means for induction heating below the top plate 2.
Two heating coils 3 a and 3 b having different diameters are concentrically arranged in a portion corresponding to the first heating port 3 below the top plate 2.
One heating coil 4 c is arranged in a portion corresponding to the second heating port 4 below the top plate 2.

First, the configuration of the first heating port 3 will be described.
The heating means constituted by the heating coil 3a and the heating coil 3b is supplied with high-frequency power by the drive circuit 10 for the heating coil 3a and the drive circuit 11 for the heating coil 3b.
The control unit 6 performs on / off operation of the switching elements of the drive circuits 10 and 11 in accordance with the operation of the heating power or the like set by the user with the operation unit 7 and the operation of the heating means of the second heating port 4 described later. The output (thermal power) of induction heating by the heating coils 3a and 3b is controlled.
The load detection means 9 detects high-frequency power supplied from the drive circuits 10 and 11 to the heating coils 3a and 3b, respectively, and the object to be heated 5 (load) is placed above the heating coils 3a and 3b. Detect whether or not.
When an instruction to start heating is given from the operation unit 7 by the operation of the user, the control unit 6 drives the drive circuits 10 and 11 in the load detection operation mode before starting heating, and the load detection unit 9 performs the load detection operation. And the drive states of the drive circuits 10 and 11 are determined based on the detection result. Details will be described later.

Next, the configuration of the second heating port 4 will be described.
The heating means of the second heating port 4 constituted by the heating coil 4c is supplied with high frequency power by the drive circuit 13 for the heating coil 4c.
The control unit 6 controls the on / off operation of the switching element of the drive circuit 13 according to the operation such as the heating power set by the user with the operation unit 7 to control the heating power of induction heating by the heating coil 4c.
When an instruction to start heating is given from the operation unit 7 by a user's operation, the control unit 6 drives the drive circuit 13 in the load detection operation mode before starting heating, and performs load detection operation by the load detection unit 12. Based on the detection result, the driving state of the driving circuit 13 is determined.

  In the first embodiment, the case where the two heating coils 3a and 3b are concentrically arranged in the first heating port 3 will be described, but the present invention is not limited to this. For example, three or more heating coils having different diameters may be arranged concentrically.

In the first embodiment, the case where the heating means corresponding to the second heating port 4 is one heating coil 4c will be described, but the present invention is not limited to this. For example, each of the first heating port 3 and the second heating port 4 may be composed of a plurality of heating coils.
In this case, both the first heating port 3 and the second heating port 4 correspond to the “first heating port” of the present invention. When one of the first heating port 3 and the second heating port 4 is regarded as a control target, the other is the “second heating port”. It corresponds to.
That is, when there are a plurality of heating ports having a plurality of heating coils, any of the plurality of heating ports corresponds to the “first heating port” of the present invention. In addition, any of the heating ports adjacent to the first heating port corresponds to the “second heating port” of the present invention.

Here, the interference sound generated when a plurality of heating ports are operated simultaneously will be described.
Adjustment of the thermal power when heating the article 5 to be heated is performed by increasing or decreasing the high-frequency current flowing through the heating coil. As means for increasing or decreasing the high-frequency current, it is realized by changing the frequency of the current flowing through the heating coil.
This is a method of controlling the current flowing through the heating coil by increasing / decreasing the impedance of the heating coil according to the frequency. To increase the heating power, the frequency is set low so that the impedance of the heating coil decreases, and conversely, the heating power is decreased. Sets a high frequency to supply a high frequency current from the drive circuit to the heating coil.
The generation of the interference sound occurs when the plurality of heating ports are driven in this way. For example, the driving frequency of the heating coil is the first because of the difference in the set heating power or the material of the object to be heated. The heating port 3 and the second heating port 4 are different from each other, and when the difference in driving frequency is less than 20 kHz, which is the audible frequency range, it is heard by the user.
Moreover, when the magnetic flux from one heating coil affects the to-be-heated object mounted in the other heating port by the relationship between the bottom face shape of the to-be-heated object 5 and the size of the heating coil. Remarkable interference sound is generated. This is because the object to be heated on the other heating port side is induction-heated by the magnetic flux between the driving frequency of its own heating coil and the different driving frequency entering from the other, The difference in drive frequency appears as interference sound.

Next, the operation of the first embodiment will be described with reference to FIGS.
FIG. 3 is a diagram for explaining the operation of the induction heating cooker according to the first embodiment of the present invention.
FIG. 3A shows a case where an object to be heated 5 having a size such that both of the heating coils 3 a and 3 b are covered is placed on the first heating port 3.
FIG. 3B shows a case where the heating coil 3 a is covered with the heated object 5 and the heated object 5 having a small diameter so as not to cover the heating coil 3 b is placed on the first heating port 3. ing.
FIG. 3C shows the relationship between the load detection result and the operation of each heating coil.

  Hereinafter, assuming that the second heating port 4 adjacent to the first heating port 3 is in a heating operation state, an operation for starting the heating operation of the first heating port 3 will be described.

When an operation for starting heating with respect to the first heating port 3 is input from the operation unit 7, the control unit 6 drives the drive circuits 10 and 11 for a certain time in the load detection operation mode.
The load detection means 9 detects whether or not the object to be heated 5 is placed above the heating coils 3a and 3b (on the top plate 2), based on the current flowing through the heating coils 3a and 3b.

As shown in FIG. 3 (A), when there is an object to be heated 5 (load) in both of the heating coils 3a and 3b, the load detecting means 9 detects the object to be heated 5 for both the heating coils 3a and 3b. The mounting state of is detected.
The control unit 6 drives the drive circuits 10 and 11 based on the detection result of the load detection means 9, determines the heating output based on the setting from the operation unit 7, and operates both the heating coils 3a and 3b. Induction heating.

On the other hand, as shown in FIG. 3B, when the object to be heated 5 is not placed above the heating coil 3b, the load detecting means 9 places the object to be heated 5 on the heating coil 3a. Is detected, and the placement of the object to be heated 5 is not detected for the heating coil 3b.
Based on the detection result of the load detection means 9, the control unit 6 drives the drive circuit 10 to operate the heating coil 3a to perform induction heating, and the drive circuit 11 is not driven and the output of the heating coil 3b is stopped. And The heating output at this time is a thermal power that can be output only by the operation of the heating coil 3a.

  In the above operation, the case where the output of the heating coil 3b on which the article to be heated 5 is not placed is stopped has been described. However, the present invention is not limited to this, and the output of the heating coil 3b is reduced. Anyway.

As described above, in the present embodiment, the first heating port 3 having the plurality of heating coils 3a and 3b and the heating that is a heating unit for the heating port disposed adjacent to the first heating port 3 are used. When induction heating the coil 4c at the same time, the outputs of the plurality of heating coils 3a and 3b are controlled based on the detection result of the load detection means 9.
For this reason, the influence which the magnetic flux radiated | emitted from the heating means of the 1st heating port 3 has on the to-be-heated object 5 mounted in the 2nd heating port 4 can be reduced.
Therefore, when a plurality of heating means are induction-heated at the same time, the generation of interference noise can be suppressed.

Further, when the heating means of the first heating port 3 and the heating means of the second heating port 4 are simultaneously induction-heated, the heating coils 3a and 3b constituting the heating unit of the first heating port are disposed above. The output of the heating coil on which the article to be heated 5 is not placed is stopped or lowered.
For this reason, generation of magnetic flux can be stopped or reduced for the heating coil 3b having a large amount of magnetic flux reaching the second heating port 4, and the influence of magnetic flux leaking to the second heating port 4 can be reduced. Generation of interference sound can be suppressed.
In addition, induction heating can be performed on the heating coil 3a with a small magnetic flux reaching the second heating port 4.
Further, by reducing the output of the heating coil in which the object to be heated 5 is not placed on the upper side, it is possible to secure as much power as possible to the object to be heated 5 placed in the first heating port 3. become.

In addition, when the size of the object to be heated 5 (bottom size) is sufficiently large and the object to be heated 5 is placed above all of the heating coils 3a and 3b constituting the heating means of the first heating port 3. The heating coils 3a and 3b constituting the heating means of the first heating port 3 are all operated by an output corresponding to the operation input from the operation unit 7.
For this reason, when there is little magnetic flux which reaches | attains the 2nd heating port 4 from the heating means of the 1st heating port 3, induction heating can be performed with the output according to the operation input from the operation part 7. FIG. Therefore, it is possible to apply the thermal power as instructed by the user.

Embodiment 2. FIG.
In the first embodiment, the interference noise suppression in the case where the two heating coils 3a and 3b are concentrically arranged in the first heating port 3 has been described.
In the second embodiment, a description will be given of a case where the arrangement of the heating coils constituting the first heating port 3 is another arrangement.

FIG. 4 is a block diagram illustrating the configuration of an induction heating cooker according to Embodiment 2 of the present invention.
In FIG. 4, an elliptical heated object 5 (pan) is placed on the first heating port 3, and a circular heated object 5 (pan) is placed on the second heating port 4. It shows the state that was done.
In FIG. 4, as the heating means corresponding to the first heating port 3 in the second embodiment, the heating coil 3a disposed at substantially the center of the first heating port 3 and the periphery of the heating coil 3a are disposed. The six heating coils 3b1 to 3b6.
Moreover, each heating coil 3a, 3b1-3b6 of the 1st heating port 3 is provided with the load detection means 9, respectively. Moreover, the drive circuit 10 (a) corresponding to the heating coil 3a and the drive circuits 11 (b1 to b6) respectively corresponding to the heating coils 3b1 to 3b6 are provided.
In addition, about another structure, it is the same as that of the said Embodiment 1, and attaches | subjects the same code | symbol to the same structure.

The “heating coil 3a” in the second embodiment corresponds to the “first heating coil” in the present invention.
The “heating coils 3b1 to 3b6” in the second embodiment correspond to the “second heating coil” in the present invention.

Next, the operation of the second embodiment will be described using FIG. 4 and FIG.
It is assumed that the second heating port 4 adjacent to the first heating port 3 is in a heating operation state, and the operation for starting the heating operation of the first heating port 3 will be described.

When an operation for starting heating is input from the operation unit 7 to the first heating port 3, the control unit 6 drives the drive circuits 10 (a) and 11 (b <b> 1 to b <b> 6) for a certain time in the load detection operation mode. Let
In the load detection means 9, the object to be heated 5 is placed above the heating coils 3a, 3b1 to 3b6 (on the top plate 2) by the current flowing through the heating coils 3a, 3b1 to 3b6 at this time. Detect whether or not.

As shown in FIG. 4, the elliptical object 5 is placed in the entire range above the heating coils 3 a, 3 b 2, 3 b 3, 3 b 5, 3 b 6 and in the almost half range above the heating coils 3 b 1, 3 b 4. In such a case, the load detection means 9 detects the placement state of the object to be heated 5 for all the heating coils 3a, 3b1 to 3b6.
When the object to be heated 5 is placed above all of the heating coils 3a, 3b1 to 3b6 constituting the heating means of the first heating port 3, the control unit 6 heats the first heating port 3. Of the heating coils 3a, 3b1 to 3b6 constituting the means, the output of at least one heating coil close to the second heating port is stopped or reduced.
For example, among the heating coils 3a, 3b1 to 3b6, the driving of the driving circuit 11 (b1) of the heating coil 3b1 closest to the second heating port 4 is stopped, and the output is stopped. The control unit 6 drives the drive circuits 10 (a) and 11 (b2 to b6) to operate the heating coils 3a and 3b2 to 3b6 to perform induction heating.

  In addition, although the case where the output of only the heating coil 3b1 is stopped or reduced has been described here, the present invention is not limited to this, and for example, the heating coil 3a, 3b1 to 3b6 is arranged on the second heating port 4 side. The output of the heating coils 3b1, 3b2, 3b6 that are being operated may be stopped or reduced. Further, the output of the heating coil 3b1 may be stopped and the output of the heating coils 3b2, 3b6 may be reduced.

On the other hand, as shown in FIG. 5, the elliptical object to be heated 5 exists in the entire range above the heating coils 3 a, 3 b 1 to 3 b 4 and a part (for example, half or less) above the heating coils 3 b 5, 3 b 6. When placed, the load detection means 9 detects the placement state of the object to be heated 5 for the heating coils 3a, 3b1 to 3b4, and places the object 5 to be heated for the heating coils 3b5 and 3b6. The position is not detected.
Based on the detection result of the load detection means 9, the control unit 6 performs heating in which the object to be heated 5 is not placed above the heating coils 3 a, 3 b 1 to 3 b 6 constituting the heating means of the first heating port 3. The output of the coils 3b5 and 3b6 is stopped or lowered. Further, induction heating is performed by operating the other heating coils 3a and 3b1 to 3b4.

  As described above, the heating target 5 (load) is sufficiently placed above the heating coil 3b1 closest to the second heating port 4 among the heating coils 3a, 3b1 to 3b6 of the first heating port 3. If there is, the magnetic flux radiated from the heating coil 3b1 and reaching the object to be heated 5 placed in the second heating port 4 is small, and the interference coil is hardly caused. Even if it does, it does not lead to the generation of interference sound.

When there are a plurality of heating coils on which the object to be heated 5 is not placed above, at least the output of the heating coil closest to the second heating port 4 among the heating coils is stopped or reduced. May be.
For example, in the example of FIG. 5, at least the output of the heating coil 3b6 closest to the second heating port 4 among the heating coils 3b5 and 3b6 on which the article to be heated 5 is not placed is stopped or reduced. May be.
When there are three or more heating coils on which the article to be heated 5 is not placed, the output of any heating coil including at least the heating coil closest to the second heating port 4 is stopped or reduced. You may do it.
As described above, by stopping or reducing the output of the heating coil closest to the second heating port 4 among the heating coils in which the article to be heated 5 is not mounted on the upper side, the second heating port 4 is mounted. It is possible to stop or reduce the generation of magnetic flux from the heating coil that most affects the generation of the interference sound of the heated object 5 placed, and to suppress the generation of the interference sound.

  In the present embodiment, the load detection means 9 detects the placement state of the article to be heated 5 when the article to be heated 5 is placed in a substantially half range above the heating coil. In the case where the object to be heated 5 is placed on a part of the heating coil (for example, less than half), the case where the placement of the object to be heated 5 is not detected has been described, but the present invention is not limited to this. Absent. For example, even if it is a part above a heating coil, you may make it detect the mounting state of the to-be-heated material 5, and when it has mounted in the whole range on a heating coil, a mounting state is detected. You may make it do.

As described above, in the present embodiment, when the heating unit of the first heating port 3 and the heating unit of the second heating port 4 are simultaneously induction-heated, the heating coils 3a and 3b1 of the first heating port 3 are used. The output of the heating coil in which the to-be-heated material 5 is not mounted is stopped or reduced among -3b6.
For this reason, generation | occurrence | production of magnetic flux can be stopped or reduced about the heating coil from which the magnetic flux which reaches | attains the 2nd heating port 4 among several heating coils of the 1st heating port 3 increases, and 1st heating The influence of magnetic flux leaking from the port 3 to the second heating port 4 can be reduced, and the generation of interference noise can be suppressed.

Moreover, even if it is a heating coil which adjoins the 2nd heating port 4 among the several heating coils of the 1st heating port 3, the to-be-heated material 5 is fully mounted above it The heating coil also performs a heating operation.
For this reason, even if it is a heating coil close to the 2nd heating port 4, there is little magnetic flux which reaches the to-be-heated object 5 mounted in the 2nd heating port 4, and it may become a cause of interference sound. When the amount is small, the heating operation can be performed, and there is an effect that the heating power can be input to the object to be heated 5 as much as possible.

Moreover, when there are a plurality of heating coils on which the object to be heated 5 is not placed above, at least the output of the heating coil closest to the second heating port is stopped or reduced.
For this reason, among the heating coils in which the object to be heated 5 is not placed on the upper side, the magnetic flux from the heating coil that most affects the generation of the interference sound of the object to be heated 5 placed in the second heating port 4. Generation | occurrence | production can be stopped or reduced, and generation | occurrence | production of an interference sound can be suppressed.

When the object to be heated 5 is placed above all of the heating coils 3a, 3b1 to 3b6 constituting the heating means of the first heating port 3, the heating means of the first heating port 3 is constituted. Among the heating coils 3a, 3b1 to 3b6 to be performed, the output of at least one heating coil adjacent to the second heating port 4 is stopped or reduced.
For this reason, the influence which the magnetic flux radiated | emitted from the heating means of the 1st heating port 3 has on the to-be-heated object 5 mounted in the 2nd heating port 4 can be reduced.

In addition, in this Embodiment 2, although demonstrated as what provided the drive circuits 10 and 11 for every heating coil which comprises the 1st heating port 3, for example, the outside heating coils 3b1-3b6 are predetermined 3 sets ( 3b1 and 3b2, 3b3 and 3b4, 3b5 and 3b6), and three drive circuits 11 may be configured. When configured with such a set of heating coils, the heating coils 3b1 and 3b2 are stopped in the case of the placement position of the article 5 to be heated shown in FIG.
Similarly, in the case of the placement position of the article 5 to be heated shown in FIG. 5, it is possible to stop the heating coils 3b5 and 3b6 and suppress the interference sound.
Moreover, since it becomes possible to reduce the number of the drive circuits 11, there exists an effect that size reduction of an induction heating cooking appliance is attained.

Embodiment 3 FIG.
In the said Embodiment 1, 2, the drive state of the heating coil was determined according to the mounting state of the to-be-heated material 5, and the form which suppresses an interference sound was demonstrated.
In the third embodiment, a mode will be described in which operation is performed such that the heating power applied to the article to be heated 5 is input with the heating power specified by the user while suppressing the interference sound.
The configuration of the third embodiment is the same as that of the first or second embodiment.
In the following description, the operation of the third embodiment will be described by taking the configuration of the second embodiment (FIG. 5) as an example.

As described in the second embodiment, in the case of the placement position of the object to be heated 5 shown in FIG. 5, the placement of the object to be heated 5 is not detected for the heating coils 3b5 and 3b6, and the heating coil 3b5, The output of 3b6 is stopped or lowered.
At this time, if the user's heating power input instruction is the maximum heating power set to the first heating port 3 (for example, 3 kW), the heating coils 3b5 and 3b6 are not driven, so the heating power specified by the user is input. It will not be possible.

  The control unit 6 of the third embodiment allocates the insufficient heating power (for example, 500 W) due to the stop of the heating coils 3b5 and 3b6 as described above to the five heating coils of the other heating coils 3a, 3b1 to 3b4. The drive circuits 10 (a) and 11 (b1 to b4) are operated such that the heating coils that perform the heating operation increase the output by 100 W each.

As described above, in the present embodiment, when the output of at least one heating coil among the plurality of heating coils constituting the heating means of the first heating port 3 is stopped or reduced, the plurality of heating coils Among them, the output of the other heating coil whose output is not stopped or decreased is increased.
For this reason, the effect of suppressing the interference sound is obtained, and the operation with the thermal power specified by the user becomes possible, and the thermal power specified by the user and the thermal power actually input coincide with each other. It becomes difficult.
In addition, since there is no longer any conflict with the designated firepower, there is also an effect that the quality of cooking is not impaired.

In the first to third embodiments, the case where the outputs of the plurality of heating coils constituting the heating means of the first heating port 3 are controlled by the detection result of the load detection means 9 has been described. This is not a limitation.
For example, when the configuration of the load detection unit 9 is omitted and the heating unit of the first heating port 3 and the heating unit of the second heating port 4 are induction-heated simultaneously, the heating unit of the first heating port 3 is configured. Of the plurality of heating coils, the output of at least one heating coil close to the second heating port may be stopped or reduced. The heating coil to be stopped or lowered may be set in advance, may be set by a user's operation, or may be automatically set according to the set heating power or the cooking menu.
Even in such a configuration, the influence of the magnetic flux radiated from the heating means of the first heating port 3 on the object to be heated 5 placed on the second heating port 4 can be reduced.
Therefore, when a plurality of heating means are induction-heated at the same time, the generation of interference noise can be suppressed.

Embodiment 4 FIG.
In the first to third embodiments, the mode in which the operation of the heating coil of the first heating port 3 is stopped in order to suppress the interference sound has been described.
In the fourth embodiment, a mode in which interference noise is suppressed by increasing the operating frequency of some of the heating coils of the first heating port 3 will be described.

FIG. 6 is a block diagram illustrating the configuration of an induction heating cooker according to Embodiment 4 of the present invention.
In FIG. 6, of the drive circuits 10 (a) and 11 (b1 to b6) that drive the plurality of heating coils 3 a, 3 b 1 to 3 b 6 constituting the first heating port 3, the closest to the second heating port 4. The driving frequency of the driving circuit 11 (b1) that drives the heating coil 3b1 is higher than the operating frequency of other driving circuits including the driving circuit 13 that drives the heating coil 4c of the second heating port 4. It is set higher than this.
For example, the operating frequency range of the driving circuit 10 (a) and the driving circuit 11 (b2 to b6) is set from 20 kHz to 50 kHz, and the operating frequency range of the driving circuit 11 (b1) is set to 65 kHz or more. That is, the operating frequency of the drive circuit 11 (b1) for driving the heating coil 3b1 is set to be equal to the drive circuits 10 (a) and 11 (b2 to b6) for driving the other heating coils constituting the heating means of the first heating port 3. ) And 15 kHz or higher than the operating frequency of the drive circuit 13.

In addition, a silicon carbide device (hereinafter referred to as “SiC device”) formed of a wide gap semiconductor such as silicon carbide, for example, in a switching element that configures the drive circuit 11 (b1) and supplies high-frequency power to the heating coil 3b1. ) Is used.
The wide band gap semiconductor is not limited to this and may be, for example, a gallium nitride material or diamond.

Since the switching element formed of such a wide band gap semiconductor has high voltage resistance and high allowable current density, the switching element can be reduced in size. By using these reduced switching elements, A semiconductor module incorporating these elements can be miniaturized.
In addition, since the heat resistance is high, the cooling structure such as the radiation fins can be downsized and the water cooling unit can be cooled down by air, so that the semiconductor module can be further downsized.
Furthermore, since the power loss is low, it is possible to increase the efficiency of the switching element, and further increase the efficiency of the semiconductor module.

  Other configurations are the same as those of the second embodiment, and the same reference numerals are given to the same portions.

  In the fourth embodiment, the configuration of the load detection unit 9 is omitted, and an operation for detecting whether or not the object to be heated 5 is placed above the heating unit of the first heating port 3 is performed. You may make it not.

Next, the operation of the fourth embodiment will be described with reference to FIG.
It is assumed that the second heating port 4 adjacent to the first heating port 3 is in a heating operation state, and the operation for starting the heating operation of the first heating port 3 will be described.

When an operation for starting heating with respect to the first heating port 3 is input from the operation unit 7 to the control unit 6, the driving circuit 10 (a) and the driving circuits 11 (b <b> 1 to b <b> 6) are applied with a heating power corresponding to the operation. Is driven at a high frequency to start the heating operation of the heating coils 3a, 3b1 to 3b6.
At this time, the controller 6 controls the drive frequency (operating frequency) of the heating coils 3a, 3b2 to 3b6 of the first heating port 3 at the same frequency between 20 kHz and 50 kHz.

On the other hand, the drive frequency (operation frequency) of the drive circuit 11 (b1) that drives the heating coil 3b1 closest to the second heating port 4 is controlled to be 65 kHz or more.
Thus, the heating coil 3b1 is always driven in a state having a frequency difference of 15 kHz or more from the other heating coils.

As described above, in the present embodiment, when the heating unit of the first heating port 3 and the heating unit of the second heating port 4 are induction-heated simultaneously, the heating unit of the first heating port 3 is configured. Among the plurality of heating coils, the operating frequency of the drive circuit that drives some of the heating coils is set to be equal to that of the drive circuit that drives other heating coils that constitute the heating means of the first heating port 3 and the second heating port. The operating frequency of the driving circuit for driving the heating means is set higher than the audible frequency.
For this reason, even if the magnetic flux radiated from a part of the heating coils constituting the heating means of the first heating port 3 is induced to the heated object 5 on the second heating port 4 side, the difference in frequency is Since it is above the audible frequency range, it is not recognized by the user as an interference sound, and the generation of the interference sound can be suppressed. Therefore, when a plurality of heating means are induction-heated at the same time, the generation of interference noise can be suppressed.
In addition, since it is not necessary to stop or reduce the output of the heating coil in order to suppress the interference noise, the thermal power specified by the user matches the thermal power that is actually input, and there is no sense of incongruity in the operation.
In addition, since there is no longer any conflict between the designated thermal power and the thermal power actually input, there is also an effect that the quality of cooking is not impaired.

In addition, among the heating coils 3a, 3b1 to 3b6 of the first heating port 3, the operating frequency of the heating coil 3b1 adjacent to the second heating port 4 is set to the other heating coils 3a, 3b2 to 3b6 and the heating coil 4c. Make it higher than the audible frequency above the operating frequency.
For this reason, among the plurality of heating coils of the first heating port 3, the magnetic flux radiated from the heating coil having a large magnetic flux reaching the second heating port 4 is the object to be heated 5 on the second heating port 4 side. Even if it is guided to the user, it is not recognized as an interference sound by the user because the frequency difference is not less than the audible frequency range, and it is possible to suppress the generation of the interference sound.

Further, among the plurality of heating coils of the first heating port 3, for example, an SiC device is used in which the switching element of the drive circuit that drives the heating coil whose operating frequency is higher than the audible frequency is formed of a wide band gap semiconductor. ing.
For this reason, even when the operating frequency is driven higher than the audible frequency, it becomes easier to drive at a higher frequency compared to the case where it is configured by a conventional silicon-based semiconductor element (IGBT). For suppression, it is easy to create an operating frequency difference from other drive circuits, and interference noise countermeasures can be easily implemented.
Further, by using the SiC device, it is possible to obtain a drive circuit with high efficiency and low loss, and it is possible to simplify the heat dissipation structure and downsize the cooling device in the induction heating cooker.

Embodiment 5 FIG.
In the fourth embodiment, the operating frequency of the drive circuit 11 (b1) that drives the heating coil 3b1 adjacent to the second heating port 4 among the heating coils 3a, 3b1 to 3b6 of the first heating port 3 is audible. The case of setting higher than the frequency has been described.
In the fifth embodiment, an effect of suppressing the occurrence of interference noise and a mode of improving the degree of freedom in setting the heating power of the first heating port 3 will be described.

FIG. 7 is a block diagram illustrating the configuration of an induction heating cooker according to Embodiment 5 of the present invention.
In FIG. 7, a SiC device formed of a wide gap semiconductor such as silicon carbide is used as a switching element constituting the drive circuit 11 (b1 to b6) of the heating coils 3b1 to 3b6.
The drive frequency of the drive circuit 11 (b1 to b6) that drives the heating coils 3b1 to 3b6 is set to be higher than the drive frequency of the drive circuit 10 (a) that drives the heating coil 3a and the drive circuit 13 that drives the heating coil 4c. It is set higher than the audible frequency.
For example, the operating frequency range of the drive circuit 10 (a) and the drive circuit 13 is set to 20 kHz to 50 kHz, and the operating frequency range of the drive circuit 11 (b1 to b6) is set to 65 kHz or more. That is, the operation frequency of the drive circuit 11 (b1 to b6) for driving the heating coils 3b1 to 3b6 arranged around the heating coil 3a is set to the operation frequency of the drive circuit 10 (a) and the drive circuit 13 for driving the heating coil 3a. The frequency is higher than the audible frequency (for example, 15 kHz or higher).
Other configurations and operations are the same as those in the fourth embodiment, and the same portions are denoted by the same reference numerals.

As described above, in the present embodiment, the operating frequency of the drive circuit 11 (b1 to b6) that drives the operation of the heating coils 3b1 to 3b6 arranged around the heating coil 3a is set to the drive for driving the heating coil 3a. The operating frequency of the circuit 10 (a) and the driving circuit 13 is set higher than the audible frequency.
For this reason, in addition to the effect of the fourth embodiment, when the object to be heated 5 of the first heating port 3 is heated, the driving frequency of the heating coil 3a disposed at the center of the first heating port 3 is also increased. It can be driven with a difference of 15 kHz or more, and it is also possible to suppress the generation of interference sound that occurs when the object to be heated 5 disposed in the first heating port 3 is induction heated at a different frequency.
Moreover, it becomes possible to arbitrarily set the heating power of the heating coil 3a and the heating coils 3b1 to 3b6 disposed on the outer periphery on the inner side and the outer side of the first heating port 3, thereby improving the cooking performance. become.

  In the fourth and fifth embodiments as well, as described in the first to third embodiments, a plurality of heating coils constituting the heating means of the first heating port 3 based on the detection result of the load detection means 9. Control for stopping or reducing the output may be performed together.

Embodiment 6 FIG.
FIG. 8 shows an induction heating cooker according to Embodiment 6 of the present invention.
As shown in FIG. 8, in the induction heating cooker according to the sixth embodiment, below the top plate 2, relatively small heating coils 20 are distributed almost uniformly.
Moreover, the load detection means 9 in this Embodiment 6 is provided for every heating coil 20, and detects whether the to-be-heated material 5 is mounted above the heating coil 20, respectively.
In addition, the drive circuit 11 according to the sixth embodiment is provided for each heating coil 20 and supplies high-frequency power to each heating coil 20.
Other configurations are the same as those in the second embodiment, and the same reference numerals are given to the same portions.

In the present embodiment, a configuration in which the display of the heating port is not provided on the top 2 may be employed.
The number of heating coils 20 may be any number. In addition, the layout of the heating coil 20 is not limited to this, and may be arranged in a honeycomb shape, or the large heating coil 20 and the small heating coil 20 may be mixed.

  Next, the operation of the sixth embodiment will be described with reference to FIGS.

When an operation for starting heating is input, the control unit 6 drives each drive circuit 11 for a predetermined time in the load detection operation mode.
As in the second embodiment, the load detection unit 9 is configured such that the object to be heated 5 is placed above each heating coil 20 (on the top plate 2) by a current flowing through each heating coil 20 or the like. Detect whether or not.
The control unit 6 obtains the placement position of the object to be heated 5 based on the detection result of each load detection means 9. And the drive circuit 11 of the heating coil 20 corresponding to the mounting position of the to-be-heated material 5 is driven, the said heating coil 20 is operated, and induction heating is performed.

However, when a plurality of objects to be heated 5 are placed on the top plate 2 and the plurality of objects to be heated are induction heated at the same time, the control unit 6 is a heating coil in which the placement state of the objects to be heated 5 is detected. 20, the output of at least one heating coil 20 adjacent to the adjacent object to be heated 5 is stopped or reduced.
For example, as shown in FIG. 9, when an elliptical object to be heated 5a and a circular object to be heated 5b are placed, the object to be heated among the heating coils 20 arranged below the object to be heated 5a. Stop or reduce the output of the heating coil closest to 5b. And the other heating coil 20 arrange | positioned under the to-be-heated material 5a is operated, and induction heating is performed.
Moreover, the output of the heating coil closest to the heated object 5a among the heated coils 20 arranged below the heated object 5b is stopped or reduced. And the other heating coil 20 arrange | positioned under the to-be-heated material 5b is operated, and induction heating is performed.

As described above, in the present embodiment, a plurality of heating coils 20 are provided that are substantially uniformly distributed below the top plate 2. And the control part 6 guide | induces the several to-be-heated object 5 simultaneously with the heating coil 20 by which the to-be-heated object 5 was mounted in the top plate 2, and the mounting state of the to-be-heated object 5 was detected upwards. In the case of heating, the output of at least one heating coil 20 adjacent to the adjacent heated object 5 among the heating coils 20 in which the placement state of the heated object 5 is detected is stopped or reduced.
For this reason, the to-be-heated material 5 can be induction-heated in the arbitrary positions on the top plate 2. FIG. In addition, when the plurality of objects to be heated 5 are simultaneously induction-heated, the influence of the magnetic flux radiated from the heating coil 20 on the other objects to be heated 5 can be reduced.
Further, generation of magnetic flux can be stopped or reduced for the heating coil 20 having a large amount of magnetic flux reaching the adjacent object to be heated 5, the influence of magnetic flux leaking to the adjacent object to be heated 5 can be reduced, and interference noise can be reduced. Can be suppressed.
Therefore, when induction heating the plurality of objects to be heated 5 at the same time, the generation of interference noise can be suppressed.
In addition, induction heating can be performed on the heating coil 20 with a small magnetic flux reaching the adjacent object to be heated 5.

  DESCRIPTION OF SYMBOLS 1 induction heating cooker main body, 2 top plate, 3 1st heating port, 3a heating coil, 3b heating coil, 4th heating port, 4c heating coil, 5 to-be-heated object, 6 control part, 7 operation part, 8 display unit, 9 load detection means, 10 drive circuit, 11 drive circuit, 12 load detection means, 13 drive circuit, 20 heating coil.

Claims (8)

A top plate on which the object to be heated is placed;
A plurality of heating ports formed on the top plate and indicating a placement position of the object to be heated;
A heating means provided for each of the heating ports, for inductively heating the object to be heated placed on the heating port;
A drive circuit for supplying high-frequency power to the heating means by an on / off operation of the switching element;
An operation unit for inputting operations related to cooking,
A control unit that controls the drive circuit based on an input from the operation unit,
Among the plurality of heating ports, at least one heating port has a corresponding heating means constituted by a plurality of heating coils,
The drive circuits supply high frequency power to the heating coils, respectively.
The controller is
Of the plurality of heating ports, the heating means is a heating port formed by a plurality of heating coils, and a second heating port is a heating port adjacent to the first heating port. In the case of simultaneously heating the object to be heated respectively placed,
Of the plurality of heating coils constituting the heating means of the first heating port, the operating frequency of the drive circuit that drives at least a part of the heating coil including the heating coil closest to the second heating port is set. ,
The operating frequency of the driving circuit that drives the other heating coil that constitutes the heating means of the first heating port and the driving circuit that drives the heating means of the second heating port is set higher than the audible frequency. Induction heating cooker featuring.   The controller is
  Based on the input from the operation unit, the operating frequency of the drive circuit is controlled so that the heating power of each heating port becomes a set heating power.
The induction heating cooker according to claim 1. The controller is
When simultaneously heating the heating means of the first heating port and the heating unit of the second heating port,
Of the plurality of heating coils that constitute the heating means of the first heating port, the operating frequency of the drive circuit that drives the part of the heating coils,
More than 15 kHz higher than the operating frequency of the drive circuit that drives the other heating coil that constitutes the heating means of the first heating port and the drive circuit that drives the heating means of the second heating port The induction heating cooker according to claim 1 or 2 . The induction heating cooker according to any one of claims 1 to 3, wherein the partial heating coil is a heating coil close to the second heating port. The heating means of the first heating port is configured by arranging a plurality of second heating coils around the first heating coil,
The induction heating cooker according to any one of claims 1 to 4 , wherein the part of the heating coils is the second heating coil. The induction heating cooking according to any one of claims 1 to 4 , wherein the heating means of the first heating port is configured by concentrically arranging a plurality of heating coils having different diameters. vessel. The induction heating cooker according to any one of claims 1 to 6 , wherein in the drive circuit for driving the part of the heating coils, the switching element is formed of a wide band gap semiconductor. The induction heating cooker according to claim 7, wherein the wide band gap semiconductor is silicon carbide, a gallium nitride-based material, or diamond.

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