JP4901829B2 - Induction heating cooker, repair method of induction heating cooker - Google Patents

Description

  The present invention relates to an induction heating cooker and a repair method thereof.

  Conventionally, regarding an induction heating cooker, “providing an induction heating cooker capable of suppressing leakage of magnetic flux in addition to an object to be heated outside the cooker. As a technique for the purpose, “DC power supply circuit 32, inverter circuit 35, heating coil 17 for heating object to be heated 38, magnetic shield means 20 for reducing leakage of magnetic flux, control Means 40 and input power detection means 41, and the control means 40 stops the power supplied to the heating coil 17 when the input power value detected by the input power detection means 41 is smaller than the first predetermined value. At the same time, when the input power value detected by the input power detection means 41 is within a range larger than the first predetermined value and smaller than the second predetermined value, the power supplied to the heating coil 17 is determined in advance. Limit power to less than the upper limit. Is proposed (Patent Document 1).

JP 2008-34397 A (summary)

In the technique described in Patent Document 1, it is determined whether or not to limit power by comparing input power with a first predetermined value or a second predetermined value. However, depending on the object of determination, an appropriate determination may not always be made only by comparison with a predetermined threshold.
For example, when determining whether or not an abnormality such as a short circuit has occurred in the heating coil, it is desirable that the abnormality can be detected before the power and current reach a predetermined threshold from the viewpoint of product safety and the like.

  The present invention has been made to solve the above-described problems, and an object thereof is to obtain an induction heating cooker capable of reliably detecting an abnormality occurring in a heating coil and a repair method thereof. .

An induction heating cooker according to the present invention includes a DC power supply circuit that supplies DC power, an inverter that receives supply of power from the DC power supply circuit and outputs high-frequency power, and receives supply of high-frequency power from the inverter. a heating coil for heating the heating object, wherein the current detecting means for detecting a current flowing through the heating coils to control the inverter, and a control unit for varying the heating power level of the heating coil, which is varied by the inverter comprising a heating power level of the heating coil, and the storage unit for storing a correspondence relationship information indicating a correspondence relationship between the current value flowing through the heating coil in a normal at each heating power level, and the control unit, heating power level The detection result of the current detection means before and after the change is acquired every time the current is changed, and the current value corresponding to the heating output level before and after the change is obtained as the correspondence If the difference between the detection results of the current detection means before and after the change of the heating output level is larger than the difference between the current values corresponding to the heating output level before and after the change, there is an abnormality in the heating coil. It is determined that it has occurred.

According to the induction heating cooker which concerns on this invention, a control part determines whether abnormality has arisen in the heating coil based on the difference of the electric current detection value before and behind changing a heating output level.
Therefore, it is possible to determine the presence or absence of abnormality from the change tendency of the current detection value before and after changing the heating output level, and the abnormality occurring in the heating coil even before the heating coil current actually shows an abnormal value. Can be detected.

Embodiment 1 FIG.
FIG. 1 is a functional block diagram of induction heating cooker 100 according to Embodiment 1 of the present invention.
The induction heating cooker 100 includes a DC power supply circuit 20, an inverter 30, a heating coil 41, a resonance capacitor 42, a current detector 50, a control unit 60, a storage unit 70, an operation unit 81, and a display unit 82.

The DC power supply circuit 20 receives supply of AC power from the AC power supply 10, converts it into DC power, and supplies it to the inverter 30.
The inverter 30 includes switching elements 31, 32, 33, and 34. By turning these switches ON / OFF, the inverter 30 converts DC power supplied from the DC power supply circuit 20 into high-frequency power and supplies it to the heating coil 41. .

The heating coil 41 is supplied with high-frequency power from the inverter 30 and induction-heats an object to be heated by electromagnetic induction.
The resonance capacitor 42 is connected in series to the heating coil 41 and forms a series resonance circuit together with the heating coil 41.
The current detector 50 detects a current flowing through the heating coil 41 and outputs a detection value to the control unit 60.

The controller 60 controls the switching elements 31 to 34 included in the inverter 30. Further, based on the detection result of the current detector 50 and correspondence data stored in the storage unit 70 described later with reference to FIG. Details will be described later.
The control unit 60 can be configured by hardware such as a circuit device that realizes the function, or can be configured by a calculation device such as a microcomputer or a CPU (Central Processing Unit) and software that defines the operation thereof. it can.

The storage unit 70 stores correspondence data described later with reference to FIG. The storage unit 70 can be configured by a storage device such as an HDD (Hard Disk Drive).
The operation unit 81 is configured by means for a user to give an operation instruction to the induction heating cooker 100, such as an operation button or a touch panel.
The display unit 82 is configured by means for displaying information such as a light emitting diode or a liquid crystal display.

FIG. 2 is a diagram illustrating a configuration example of the correspondence data stored in the storage unit 70.
The correspondence data is stored in a two-column table format, and has a “heating output level” column and a “heating coil current” column.
The storage format is not necessarily limited to the table format, and any format having similar data can be used.

In the “heating output level” column, a value representing an integer value of the heating output when the heating coil 41 heats the object to be heated is stored. Here, an example in which the minimum output level is 1 and the maximum output level is 12 is shown.
The “heating coil current” column stores the current value (heating coil current) of the heating coil 41 corresponding to the value of the “heating output level” column.

  The correspondence data is data representing an ideal correspondence between the heating output level and the heating coil current. For example, when “heating output level = 1”, the current flowing through the heating coil 41 is 1.5 (A), which is an ideal state. Yes.

Heretofore, the configuration of the induction heating cooker 100 according to the first embodiment has been described.
Next, the abnormality that occurs in the heating coil 41 and the heating coil current at that time will be described.

FIG. 3 is a diagram for explaining how a rare short occurs in the heating coil 41.
The rare short is a state in which the coils are almost completely short-circuited due to, for example, deterioration of the insulating film of the heating coil 41.
When a rare short occurs, the current flowing through the heating coil 41 tends to increase. If the rare short state is left as it is, the coils are completely short-circuited and an overcurrent flows through the heating coil 41, causing a failure of the induction heating cooker 100.

FIG. 4 is a graph showing the correspondence between the heating output level and the heating coil current.
When the heating coil 41 is normal and no abnormality occurs, the heating output level and the heating coil current are in a directly proportional relationship.
When a rare short occurs in the heating coil 41, when the heating output level rises to a certain level, the rising gradient of the heating coil current increases, and the heating coil current significantly increases with respect to the heating output level.
When the heating coil 41 is completely short-circuited, an overcurrent flows through the heating coil 41.

  In the first embodiment, paying attention to the correspondence relationship between the heating output level and the heating coil current as shown in FIG. 4, a rare short occurs in the heating coil 41 when the rising gradient of the heating coil current increases. Judge that it is.

  Focusing on the gradient, if the heating output level is increased as it is, it is predicted in advance that the heating coil current will increase excessively, and the heating output level is increased so that the coils are completely short-circuited. The intention is to prevent it from happening.

In order to obtain the change gradient of the heating coil current, the difference between the heating coil current values before and after the heating output level is changed may be obtained.
For example, when the heating output level is changed from 1 to 5, the detection value of the current detector 50 is first acquired at the time of the heating output level 1 before the change, and the heating output level is changed to 5 for a predetermined time. After the elapse of time, the detection value of the current detector 50 may be acquired again to obtain the difference between the two detection values.

Whether or not the obtained difference is appropriate can be determined by referring to the correspondence data in FIG.
When the heating output level is changed from 1 to 5, the difference between the current values of the heating output levels 1 and 5 is “7.5−1.5 = 6.0”, so the calculated difference is 6.0 ( If it is larger than A), it can be determined that there is a possibility that a rare short has occurred.

  Alternatively, according to the correspondence data in FIG. 2, an increase value of the heating coil current every time the heating output level increases by 1 is ideally 1.5 (A). Therefore, when the rising gradient exceeds this, It can also be determined that a rare short has occurred.

FIG. 5 is a table showing the difference value of the heating coil current before and after the heating output level change, calculated based on the correspondence data in FIG.
After determining the difference between the heating coil current values as described above, when determining whether the difference is appropriate, an ideal difference value may be calculated each time from the correspondence data in FIG. Alternatively, a correspondence table as shown in FIG. 5 may be stored in the storage unit 70 in advance and used.

The abnormality that occurred in the heating coil 41 and the heating coil current at that time have been described above.
Next, an example of operation when the induction heating cooker 100 according to the first embodiment detects an abnormality occurring in the heating coil 41 will be described in the following (Step 1) to (Step 8).

(Step 1)
The user turns on the power of the induction heating cooker 100. Next, the user operates the operation unit 81 to set the heating output level to “1” and starts cooking.
(Step 2)
The controller 60 controls the switching elements 31 to 34 included in the inverter 30 and performs a heating operation while adjusting the current flowing through the heating coil 41 to 1.5 (A).

(Step 3)
The user operates the operation unit 81 to set the heating output level to “5”.
(Step 4)
When receiving an operation instruction indicating that the heating output level should be “5” from the operation unit 81, the control unit 60 acquires the detection value of the current detector 50 before changing the heating output. Here, it is assumed that it was 1.45 (A).
Next, the control unit 60 controls the switching elements 31 to 34 so as to adjust the current flowing through the heating coil 41 to 7.5 (A).

(Step 5)
The control unit 60 acquires the detection value of the current detector 50 after a predetermined time has elapsed. Here, it is assumed that it was 7.76 (A).
Even if the switching elements 31 to 34 are driven and controlled so that the current flowing through the heating coil 41 is adjusted to 7.5 (A), the current value is immediately 7.5 ( This is because a certain time is required instead of A).

(Step 6)
The control unit 60 obtains a difference between detection values of the current detector 50 before and after the heating output level is changed from “1” to “5”. Here, it is calculated | required as "7.76-1.45 = 6.31". Similarly, the rising gradient of the heating coil current is obtained as “6.31 / (5-1) = 1.5775”.

(Step 7)
The control unit 60 determines whether or not the difference obtained in Step 6 is appropriate based on the correspondence data in FIG. 2 or the difference table obtained in advance as shown in FIG.
Here, the ideal value of the difference is “7.5−1.5 = 6.0”, and the actually detected difference value is 6.31 (the rising gradient is 1.5775). The rising slope of is greater than the ideal value.
Therefore, the control unit 60 determines that there is a possibility that a rare short has occurred in the heating coil 41.

(Step 8)
The control unit 60 instructs the display unit 82 to output the abnormality content of the heating coil 41.
The display unit 82 displays that there is a possibility that a rare short has occurred in the heating coil 41 based on the instruction.

The procedure for detecting an abnormality occurring in the heating coil 41 has been described above.
In general, when an abnormality such as a rare short occurs, the abnormal current appears more prominently as the heating output level is increased.
On the other hand, according to the above-described procedure, the abnormality determination is performed based on the rising gradient of the current. Therefore, the abnormality determination can be performed in the middle of increasing the heating output level, and the abnormal current is actually generated in the heating coil 41. Abnormality detection can be performed at a point before flowing.

  In step 7, the criterion for determining whether or not a rare short has occurred may be the difference between the current detection values before and after the heating output level is changed, and this is further divided by the amount of change in the heating output level. A gradient may be used.

  In the first embodiment, a full bridge type inverter circuit is illustrated, but the present invention is not limited to this, and for example, a similar abnormality detection method can be used for a half bridge circuit.

As described above, according to the first embodiment, the controller 60 determines whether or not an abnormality has occurred in the heating coil 41 based on the difference between the detection values of the current detector 50 before and after the heating output level is changed. Determine whether.
As a result, it is possible to detect that an abnormality has occurred in the heating coil 41 at the time when a sign of an abnormal current flowing in the heating coil 41 is found, which contributes to early detection of the abnormality.

  In addition, according to the first embodiment, it is possible to detect an abnormality at a point before the heating coil 41 is completely short-circuited and prompt the user to replace the heating coil 41, so that the product deterioration resistance can be improved. it can.

Embodiment 2. FIG.
In Embodiment 1, the example which determines whether abnormality has arisen in the heating coil 41 based on the difference of the detected value of the current detector 50 before and after changing a heating output level was demonstrated.
On the other hand, instead of or in combination with the abnormality determination based on the detection difference value, the detection value of the current detector 50 corresponds to the value of the “heating coil current” column in FIG. 2 corresponding to the heating output level at that time. When it exceeds, it can also be determined that an abnormality has occurred in the heating coil 41.

  While the abnormality determination based on the current gradient preliminarily determines the occurrence of the abnormal current, the abnormality determination based on whether the heating coil current exceeds the value in the “heating coil current” column of FIG. It can be said that this is a technique for detecting the occurrence of an abnormality after the occurrence of an error.

Embodiment 3 FIG.
In the first and second embodiments, it has been described that when the control unit 60 detects that an abnormality has occurred in the heating coil 41, the display unit 82 displays that fact.
On the other hand, considering the case where the degree of abnormality is large, from the viewpoint of product safety, it may be considered that the current flowing through the heating coil 41 is interrupted instead of or in combination with the display on the display unit 82. .

  Examples of the method for interrupting the current flowing through the heating coil 41 include the following (interruption method 1) to (interruption method 4).

(Blocking method 1)
When the controller 60 determines that an abnormality has occurred in the heating coil 41, the controller 60 turns off all the switching elements 31 to 34 included in the inverter 30 and stops the operation of the inverter 30.
(Blocking method 2)
When the controller 60 determines that an abnormality has occurred in the heating coil 41, the controller 60 turns off the power of the induction heating cooker 100.

(Blocking method 3)
If the controller 60 determines that an abnormality has occurred in the heating coil 41, the controller 60 causes the heating coil 41 to burn and burn. For example, it is conceivable that the duty ratio of the switching elements 31 to 34 is extremely increased, or the upper and lower switching elements 31 and 34 are momentarily short-circuited.
Note that when an overcurrent is passed through the heating coil 41, care should be taken to suppress the current value to such an extent that the switching elements 31 to 34 are not damaged.

(Blocking method 4)
The above blocking methods 1 to 3 are appropriately combined.
For example, first, the interruption method 1 is executed to stop the operation of the inverter 30 so that power is not supplied to the heating coil 41. When the heating coil current does not decrease immediately, the interruption method 2 or the interruption method 3 is executed. .
This is because the current value decreases with time delay due to the action of the heating coil 41. If the interruption method 2 is not sufficient, the heating coil is completely damaged by using the interruption method 3 so that no overcurrent continues to flow.
When it is better to immediately interrupt the heating coil current from the viewpoint of safety, such as when the heating coil current value is extremely large, the interruption method 2 or the interruption method 3 may be executed from the beginning.

In addition, from the viewpoint of enhancing safety, the control unit 60 displays the fact on the display unit 82 when detecting that an abnormality has occurred in the heating coil 41 even when cooking is performed. Alternatively, the current flowing through the heating coil 41 may be cut off.
For example, when the user increases the heating output level during cooking, when it is found that the rising gradient of the heating coil current is excessively large, the above-described measures may be taken.

As described above, according to the third embodiment, when the control unit 60 determines that an abnormality has occurred in the heating coil 41, it interrupts the current flowing through the heating coil 41.
Thereby, it can prevent that overcurrent continues flowing into the heating coil 41, and can avoid danger, such as a fire.

  Further, in the third embodiment, depending on the degree of abnormality of the heating coil current, the above-described (shut-off method 1) to (shut-off method 4) are executed in an appropriate combination so that the degree of abnormality of the heating coil 41 is increased. Necessary and sufficient measures can be implemented accordingly.

Embodiment 4 FIG.
In the first to third embodiments, the abnormality determination of the heating coil 41 is described before and after the heating output level is changed. That is, the abnormality determination of the heating coil 41 is performed when the heating coil 41 is actually performing the heating output.
Typically, when the user is cooking by heating, it can be considered that abnormality determination of the heating coil 41 is performed by any of the methods described so far.

On the other hand, even when the user is not cooking, it may be possible to determine whether the heating coil 41 is abnormal.
Therefore, in the fourth embodiment of the present invention, a special operation mode is provided in which the abnormality determination of the heating coil 41 can be performed other than during cooking. Hereinafter, the procedure for executing this operation mode will be described in (Step 1) to (Step 8).

(Step 1)
When the user is not cooking, the operation unit 81 instructs the heating coil 41 to perform abnormality determination. An operation signal to that effect is output to the control unit 60.
(Step 2)
The control unit 60 controls the switching elements 31 to 34 to set the heating output level to “1”. In the data example of FIG. 2, the heating coil current is adjusted to 1.5 (A).

(Step 3)
The control unit 60 acquires the detection value of the current detector 50.
(Step 4)
The control unit 60 drives and controls the switching elements 31 to 34 and sets the heating output level to the maximum value “12”. In the data example of FIG. 2, the heating coil current is adjusted to 18.0 (A).

(Step 5)
The control unit 60 acquires the detection value of the current detector 50 after a predetermined time has elapsed.
(Step 6)
The control unit 60 obtains a difference between detection values of the current detector 50 before and after the heating output level is changed from “1” to “12”. Similarly, the rising gradient of the heating coil current is obtained.

(Step 7)
The control unit 60 determines whether or not the difference obtained in Step 6 is appropriate based on the correspondence data in FIG. 2 or the difference table obtained in advance as shown in FIG. You may determine using an ascending gradient.
(Step 8)
When it is determined in step 7 that the heating coil 41 has an abnormality, the control unit 60 instructs the display unit 82 to output the abnormality content of the heating coil 41.
The display unit 82 displays that an abnormality has occurred in the heating coil 41 based on the instruction.
Moreover, the control part 60 may interrupt | block the electric current which flows into the heating coil 41 as demonstrated in Embodiment 3. FIG.

The special operation mode for determining the abnormality of the heating coil 41 has been described above even during cooking.
The reason why the heating output level is set to the maximum value in Step 4 is that it is possible to estimate that no abnormality has occurred unless the abnormality of the heating coil 41 is detected at the maximum output.
Moreover, the reason why the heating output level is changed from “1” to “12” is that the amount of change in the heating coil current is larger and the abnormality is more easily detected when the heating output level change width is increased.
Although it is not always necessary to change the heating output level from “1” to “12”, it is preferable to change the heating output level as much as possible from the low output level to the high output level in order to detect abnormality. .

In the fourth embodiment, it has been described that the abnormality determination is performed by increasing the heating output level from 1 to 12, but it is not always necessary to increase the heating output level from 1 to 12 in one step. Thus, the abnormality determination may be performed for each level.
By doing in this way, for example, it can be determined that “the heating current level 1 to 5 does not cause an abnormal current to flow”.
Furthermore, a message such as “It is possible to use the heating power levels 1 to 5 but repair or replace the heating coil as soon as possible” can be displayed on the display unit 82. Thus, the user can continue to use the induction heating cooker 100 within a range of a constant heating output level until the repair of the heating coil 41 is completed, which is convenient.
If the user instructs to operate at the heating output level 6 or higher, the control unit 60 ignores the instruction and controls the inverter 30 to continue the operation in the range of the heating output levels 1 to 5. Good.

  As described above, according to the fourth embodiment, the heating output level is changed from “1” to “12” and the special operation mode for determining the abnormality of the heating coil 41 is provided. Even if not, abnormality determination can be performed at any time.

Embodiment 5 FIG.
In the first to fourth embodiments described above, it has been described that it is determined that an abnormality such as a rare short has occurred in the heating coil 41 when the heating coil current rises excessively.
On the other hand, when the heating coil current does not rise sufficiently, there may be an abnormality other than an abnormality such as a rare short. Moreover, the abnormality is not necessarily limited to the abnormality of the heating coil 41, and may be an abnormality of other functional units.

  In this case, the control unit 60 may prompt the user to take appropriate measures by displaying at least that an abnormality has occurred on the display unit 82 and displaying a message prompting for repair as necessary.

Embodiment 6 FIG.
The correspondence data described with reference to FIG. 2 has a predetermined value, but is not necessarily limited to this. For example, the correspondence data is configured to hold different correspondence data depending on the type of pan. May be.
Specifically, the following (corresponding relationship data configuration example 1) to (corresponding relationship data configuration example 2) can be considered.

(Correspondence relationship data configuration example 1)
Means for detecting the type of the object to be heated using any known technique is provided in the induction heating cooker 100 in advance. The storage unit 70 stores correspondence data for each type of object to be heated.
When the control unit 60 reads the correspondence data from the storage unit 70, the corresponding correspondence data is read based on the result of detecting the type of the object to be heated.

(Correspondence relationship data configuration example 2)
In FIG. 2, it is described that the heating coil current changes by “1.5 (A)” every time the heating output level changes by “1”, but this change gradient varies depending on the type of the pan and the like.
Normally, when the heating output level is increased by one, the heating coil current rises almost linearly in proportion to it, but when a rare short occurs, the heating coil current greatly increases in a curve as the power increases. To rise.
Therefore, paying attention to the change in the inclination of the heating coil current regardless of the type of the pan, the control unit 60 has a low heating output level (for example, heating output level = minimum) and a high heating output level (for example, heating output level = Compare the slope of the current at the maximum).
Specifically, when changing the heating output level, the control unit 60 measures the actual change of the heating coil current using the detection result of the current detector 50, and uses this to measure the correspondence data in FIG. Is obtained by calculation.
When the heating coil current is greatly increased in a curve at a high heating output level, the control unit 60 determines that a rare short has occurred in the heating coil.
However, when the actual change amount of the heating coil current is larger than the maximum allowable value, it is determined that an abnormality has occurred.

  The method described in the sixth embodiment can be used in combination with the method of the other embodiments.

Embodiment 7 FIG.
In the above first to sixth embodiments, it has been described that the abnormality determination is performed using the detection result of the current detector 50 and the correspondence data of FIG.
However, when the control unit 60 gives priority to adjusting the power based on the detection result of the current detector 50, even if the current change amount fluctuates due to occurrence of an abnormality such as a slight rare short, the switching element of the inverter 30 There is a possibility that the abnormality of the current change amount is suppressed by giving priority to the power adjustment by adjusting the duty.
In this case, since a slight current abnormality change due to a slight rare short is suppressed by the control unit 60 itself, it is determined that the abnormality of the heating coil 41 is determined based on the determination criterion as to whether the current change amount is abnormal. It becomes difficult.

Therefore, when performing such power adjustment, the control unit 60 detects that the duty of the switching element has changed instead of the detection result of the current detector 50, and determines the occurrence of an abnormality in the heating coil 41 based on this. You may make it do.
Specifically, when a rare short occurs, the heating coil current easily flows, and therefore the control unit 60 reduces the duty of the switching element so as to keep the power constant. With this, it may be determined that a rare short has occurred in the heating coil.
It can be determined by using an appropriate threshold or the like how much the duty is reduced to determine that a rare short-circuit has occurred.

  The power adjustment refers to supplying power corresponding to the set value of the heating output level to the heating coil. For example, when changing the heating output level to a high value, the control unit 60 controls the duty so as to supply large power to the heating coil.

The method described in the seventh embodiment can be used in combination with the method of the other embodiments.
For example, the method described in the seventh embodiment is used when detecting a minor rare short, and the method according to another embodiment is used in other cases.

Embodiment 8 FIG.
In the above first to seventh embodiments, if it is determined that an abnormality has occurred in the heating coil 41, the abnormal state is likely to be improved if only the heating coil 41 is replaced.
Therefore, when the display unit 82 displays that the heating coil 41 is abnormal, the user requests the manufacturer to replace only the heating coil 41. Thereby, the induction heating cooking appliance 100 can be rapidly restored to a normal state, which contributes to the convenience of the user.

Alternatively, a message indicating the number or position of the heating coil 41 in which an abnormality has occurred may be displayed on the display unit 82.
The user sees the message and tells the manufacturer the contents of the message.
Based on the content of the message, the manufacturer or the like determines the abnormal part and replaces only the heating coil 41 in which the abnormality has occurred.
Thereby, the induction heating cooking appliance 100 is rapidly restored to a normal state.

3 is a functional block diagram of induction heating cooker 100 according to Embodiment 1. FIG. It is a figure which shows the structural example of the corresponding data stored in the memory | storage part. It is a figure explaining a mode that the rare short has arisen in the heating coil. The correspondence relationship between the heating output level and the heating coil current is graphed. It is a table | surface which shows the difference value of the heating coil electric current calculated based on the correspondence data of FIG. 2 before and after a heating output level change.

Explanation of symbols

  10 AC power supply, 20 DC power supply circuit, 30 inverter, 41 heating coil, 42 resonant capacitor, 50 current detector, 60 control unit, 70 storage unit, 81 operation unit, 82 display unit, 100 induction heating cooker.

Claims (15)

A DC power supply circuit for supplying DC power;
An inverter that receives power supply from the DC power supply circuit and outputs high-frequency power;
A heating coil that heats an object to be heated by receiving a supply of high-frequency power from the inverter;
Current detecting means for detecting a current flowing in the heating coil;
A control unit that controls the inverter and varies a heating output level of the heating coil;
A storage unit storing correspondence information representing a correspondence relationship between the heating output level of the heating coil that is varied by the inverter and the current value that flows through the heating coil at each heating output level at a normal time;
With
The controller is
Obtain the detection result of the current detection means before and after changing the heating output level,
Obtain the current value corresponding to the heating output level before and after the change based on the correspondence information,
The difference between the detection results of the current detection means before and after the change of the heating output level is
When larger than the difference between the current values corresponding to the heating output level before and after the change,
It is determined that an abnormality has occurred in the heating coil. An induction heating cooker, characterized in that: The storage unit
The induction heating cooker according to claim 1, wherein the correspondence information is stored for each heating output level. The controller is
The detection result of the current detection means is
When larger than the current value corresponding to the heating output level after the change,
The induction heating cooker according to claim 1 or 2, wherein it is determined that an abnormality has occurred in the heating coil. The controller is
When it is determined that an abnormality has occurred in the heating coil,
The induction heating cooker according to any one of claims 1 to 3, wherein an electric current flowing through the heating coil is cut off. The controller is
When it is determined that an abnormality has occurred in the heating coil,
The induction heating cooker according to claim 4, wherein the operation of the inverter is stopped. The controller is
When it is determined that an abnormality has occurred in the heating coil,
The induction heating cooker according to claim 4 or 5, wherein the induction heating cooker is turned off. The controller is
When it is determined that an abnormality has occurred in the heating coil,
Supplying an overcurrent to the heating coil to burn out the heating coil;
The induction heating cooker according to any one of claims 4 to 6, wherein an electric current flowing through the heating coil is cut off. The controller is
When it is determined that an abnormality has occurred in the heating coil,
Regardless of whether the heating coil is heating an object to be heated,
The induction heating cooker according to any one of claims 4 to 7, wherein an electric current flowing through the heating coil is cut off. The controller is
Receiving an instruction to determine whether or not an abnormality has occurred in the heating coil;
Change the heating output level from low level to high level and obtain the detection result of the current detection means before and after the change,
Obtain the current value corresponding to the heating output level before and after the change based on the correspondence information,
The difference between the detection results of the current detection means before and after the change of the heating output level is
When larger than the difference between the current values corresponding to the heating output level before and after the change,
The induction heating cooker according to any one of claims 1 to 8, wherein it is determined that an abnormality has occurred in the heating coil. The induction heating cooker according to any one of claims 1 to 9, further comprising a display unit that displays the fact when abnormality occurs in the heating coil. The controller is
Any of claims 1 to 3, characterized in that for controlling the inverter to continue operation at the lower than the determined heating power level that an abnormality in the heating coil is caused heating power level, or The induction heating cooker according to claim 9 or claim 10, which is dependent on any one of claims 1 to 3 . Means for detecting the type of the object to be heated;
The storage unit
Storing the correspondence data for each type of the object to be heated;
The controller is
The induction heating according to any one of claims 1 to 11, wherein whether or not an abnormality has occurred in the heating coil is determined using the correspondence data corresponding to the type of the object to be heated. Cooking device. The controller is
Obtaining the detection result of the current detection means before and after changing the heating output level and storing the difference as the correspondence information in the storage unit,
When the heating output level is further increased,
The induction heating cooker according to any one of claims 1 to 11, wherein it is determined whether or not an abnormality has occurred in the heating coil using the correspondence information. The inverter includes a switching element,
The controller is
To keep the power supplied to the heating coil at a value corresponding to the heating output level,
Control the switching duty based on the detection result of the current detection means,
When changing the duty despite not changing the heating output level,
The induction heating cooker according to any one of claims 1 to 13, wherein it is determined that an abnormality has occurred in the heating coil. A method for repairing an induction heating cooker according to any one of claims 1 to 14,
When the controller determines that an abnormality has occurred in the heating coil,
A method of repairing an induction heating cooker, characterized in that only the heating coil is replaced.

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