JP4302592B2 - Induction heating cooker - Google Patents

Description

  The present invention relates to an induction heating cooker including a plurality of electromagnetic induction heating coils.

In a conventional cooking device, an ultrasonic vibrator that generates ultrasonic vibrations driven by a second inverter circuit is attached to the bottom of a cooking pan that is induction-heated by a heating coil connected to the first inverter circuit. In addition, the ultrasonic vibration is applied to the cooking pan by an ultrasonic vibrator to perform cooking while suppressing the burning (for example, see Patent Document 1).
JP 2000-184963 A (first page, FIG. 1)

  In the conventional heating cooker as described above, since the ultrasonic wave is attached to the bottom of the cooking pan, the ultrasonic wave can be applied only to the dedicated pan that is equipped with the ultrasonic wave and is a cooking pan. There was a problem that the cleaning ability of the later cooking pan was poor, and when spilling from the cooking pan or the like occurred, the soup or the like was directly applied to the ultrasonic vibrator, which could cause failure.

  In addition, an ultrasonic transducer is required to generate ultrasonic waves, and a second inverter circuit for driving the ultrasonic transducer is required, resulting in a complicated structure and an increase in cost. there were.

  The present invention has been made to solve the above-mentioned problems, and it is possible to apply an ultrasonic wave regardless of the cooking pan, and a waterproof measure is taken due to spilling from the pan. An object of the present invention is to obtain an induction heating cooker that can reduce costs by eliminating the need for a series of devices such as an ultrasonic vibrator and a second inverter circuit for applying sonic vibration.

An induction heating cooker according to the present invention includes a rectifier circuit that rectifies a current from an AC power source, an inverter circuit that is connected to an output side of the rectifier circuit and converts the current into a high-frequency current, and an output side of the inverter circuit. A heating coil that is connected and induction-heated to the cooking pan when supplied with a high-frequency current; a magnetic flux modulation plate that is disposed above the heating coil and reflects a high-frequency of an alternating magnetic field generated from the heating coil; Drive frequency control means for outputting a drive signal for changing the drive frequency to detect the resonance frequency at which the pan resonates, the vibration sensor for detecting the vibration of the cooking pan, and the drive frequency of the drive signal. Resonance frequency detection means for detecting a resonance frequency at which the cooking pan resonates based on the output of the vibration sensor in a changed state; and the resonance frequency detection An induction heating cooker means and a control unit for outputting a resonant frequency or the drive signal of an integral multiple detected from the driving frequency control unit, provided in the operation unit, for output adjustment to adjust the firepower An encoder switch; and power control means for outputting to the inverter a drive signal having a drive frequency that provides a heating power set by the output adjustment encoder switch, and the control unit includes the output adjustment encoder in the power control means. A command for driving the inverter circuit so as to have a thermal power set by a switch and a command for driving the inverter circuit at a resonance frequency or an integer multiple thereof are alternately sent to the drive frequency control means, and the inverter circuit A drive signal of the drive frequency of the set fired power controlled from the control means and the drive frequency control means It is obtained so as to be driven alternately by the resonant frequency or the drive signal of the integral multiple of the.

According to the induction heating cooker of the present invention, when the output adjustment encoder switch is operated and set to various heating powers, the control unit has an inverter circuit so that the heating power set by the output adjustment encoder switch is set in the power control means. And a command for driving the inverter circuit at the resonance frequency or an integral multiple thereof are alternately sent to the drive frequency control means, and the inverter circuit sends a drive signal of the drive frequency of the set thermal power controlled by the power control means. And the resonance frequency from the drive frequency control means or an integral multiple of the drive signal, and the set power and the resonance frequency or the integral multiple of the high frequency are alternately supplied to the heating coil to perform cooking. Therefore, various settings of the thermal power level are possible, and it is possible to apply ultrasonic waves other than dedicated keys such as stew. You can apply an ultrasonic wave to have cooking has the advantage that good cooking is possible.

Embodiment 1
1 is a block diagram showing the configuration of the induction heating cooker according to Embodiment 1 of the present invention, FIG. 2 is a flowchart showing the operation of the induction heating cooker, and FIG. 3 is at the time of electromagnetic induction heating of the induction heating cooker. It is a work schematic diagram of an alternating magnetic field.
In FIG. 1, an operation unit 2 of a cooking device body 1 of an induction heating cooking device (IH cooking heater) includes a main switch 2a for turning on / off the power, a stew key 2b for performing stew cooking, and a desired cooking time ( A timer switch 2c capable of setting the cooking end time) is provided. A top plate 3 made of a nonmagnetic material is installed on the top surface of the cooker body 1. On the top plate 3, a cooking pan 5 for heating and cooking the object to be heated is placed.

  A heating coil 5 for heating the cooking pan 4 is disposed in the vicinity of the lower side of the top plate 3 in the cooker body 1. On the lower surface of the top plate 3, a temperature sensor 6 that is, for example, a thermistor for measuring the temperature of the bottom of the cooking pan 4 and a vibration sensor 7 for measuring the magnitude of vibration of the cooking pan 4 are attached. . Further, between the top plate 3 and the heating coil 5, for example, a ring-shaped magnetic flux modulation plate 8 made of a nonmagnetic metal material such as copper, aluminum, silver, or gold is disposed concentrically with respect to the center of the pan bottom. ing.

A current from the AC power supply 10 is rectified by a rectifier circuit 11, and an inverter circuit 12 is connected to the output side of the rectifier circuit 11. The inverter circuit 12 is driven by a drive signal having a drive frequency that is a high frequency created by the frequency creating means 13, and a high-frequency current output from the inverter circuit 12 is supplied to the heating coil 5. The drive frequency which is the drive signal of the frequency creating means 13 is changed by the drive frequency changing means 14. The drive frequency changing means 14 is for changing the drive frequency at a certain frequency interval and time interval. For example, the output set by the stew key 2b is 400 W, for example, and is used as the drive frequency when outputting it. In this case, the frequency is changed in the direction of increase and decrease in 0.5 KHz increments from the drive frequency, the drive signal of the drive frequency of that value is generated and output to the inverter circuit 12, and the heating coil 5 It controls the firepower.
Therefore, the frequency creating means 13 and the drive frequency changing means 14 constitute a drive frequency control means for outputting a drive signal having a drive frequency that changes to the inverter circuit 12.

The pot bottom temperature determining means 15 outputs a determination signal that determines that the pot bottom temperature detected by the temperature sensor 6 is equal to or higher than a predetermined temperature to the control unit 21. The resonance frequency detection means 16 outputs a detection signal to the control unit 21 that detects that the vibration detected by the vibration sensor 7 has reached the resonance frequency with the natural frequency of the cooking pan 4. The pan discriminating means 17 discriminates the presence / absence of the cooking pan 4 and whether or not the cooking pan 4 is an appropriate cooking pan 4 from the high-frequency current flowing in the heating coil 5, and outputs the discrimination signal to the control unit 20.
This pan discriminating means 17 is configured to determine whether there is an abnormality on the heating coil 5 (ie, whether there is a cooking pan 4 on the heating coil 5) and the cooking pan 4 based on a combination of a high-frequency current and voltage flowing through the heating coil 5, for example. Whether the magnetic system or the non-magnetic system is discriminated, its specific configuration is known, for example, as described in JP-A-2002-75623.

The lamp 18 serving as the abnormality notifying means blinks by a blinking signal output from the controller 21 based on an abnormality detection signal indicating that the cooking pot 4 of the pot discrimination means 17 is not present or is not an appropriate cooking pot 4 . The abnormality notification means may be a buzzer or the like other than the lamp 18.
The first timer 19 has the cooking pan 4 of the pan discriminating means 17 and starts its operation based on a discrimination signal indicating that the cooking pan 4 is an appropriate cooking pan 4. Is output to the control unit 21.
The second timer 20 operates during the cooking time set by the timer switch 2 c provided in the operation unit 2 and outputs a timer signal to the control unit 21.
The control unit 21 receives signals from the operation unit 2, the pan bottom temperature determining unit 15, the resonance frequency determining unit 16, the pan determining unit 17, the first and second timers 19 and 20, and the like. The changing means 14 and the like are driven and controlled so that a high-frequency current flows through the heating coil 5.

Next, operation | movement of the induction heating cooking appliance of Embodiment 1 of this invention is demonstrated based on the chart of FIG.1 and FIG.2. For convenience of operation, the cooking operation will be described first, and then the operation of the magnetic flux modulation plate 7 will be described.
First, after placing the cooking pan 4 containing the object to be heated on the top plate 3 of the cooker body 1, the main switch 2a of the operation unit 2 is turned on and the power is turned on (step S1). . After that, the stew key 2b of the operation unit 2 is turned on (step S2).

  Then, the pot discriminating means 17 determines whether or not the cooking pot 4 is present and whether or not it is a suitable cooking pot 4 (step S3). When the pan discriminating means 17 judges that the cooking pan 4 is not placed or is not an appropriate cooking pan 4, the discrimination signal is output to the control unit 21. If it does so, the control part 21 will send a blink signal to the lamp | ramp 18, and will blink the lamp | ramp 18 and will display an error (step S3). Thereby, the user can know whether or not the suitable cooking pan 4 is placed on the top plate 3.

  When the pot discriminating means 17 determines that the cooking pan 4 is placed or is an appropriate cooking pan 4, the discrimination signal is output to the control unit 21. Then, the control unit 21 activates the first timer 19 (step S5). The first timer 19 is a safety timer. During a predetermined timer time from when the first timer 19 is started to when the first timer 19 is finished, the user switches the timer switch 2c of the operation unit 2 for a certain time during cooking. When the control unit 21 does not operate and does not receive the operation signal of the timer switch 2c, the control unit 21 sends a drive stop signal to the frequency generating means 13 at the end of the timer time, and stops the power supply to the heating coil 5 It is.

Simultaneously with the operation of the first timer 19, the control unit 21 operates so that the frequency generating means 13 outputs the drive signal of the drive frequency set when the stew key 2b is operated, and the drive frequency change The means 10 is operated. Then, the drive frequency changing means 10 sends a command to change the drive frequency to the frequency creating means 13, and the frequency creating means 13 increases or decreases the drive frequency of the drive signal for driving the inverter circuit 13 from the current drive frequency. Change direction.
The vibration sensor 7 detects the vibration frequency and vibration amplitude of the cooking pan 4 and inputs a detection signal to the resonance frequency detection means 16. The frequency and vibration of the cooking pan 4 resonate and have a maximum amplitude when the drive frequency matches the natural frequency of the cooking pan 4.

Therefore, the resonance frequency detection means 16 sends the drive frequency at which the amplitude of vibration is maximized from the detection signal of the vibration sensor 7 to the control unit 21 as the resonance frequency (step S7).
If it does so, the control part 21 will send the command which drives the inverter circuit 13 to the frequency preparation means 13 with the resonance frequency. Then, since the frequency creating means 13 drives the inverter circuit 12 with a drive signal having a resonance frequency, a high-frequency current having the resonance frequency is supplied to the heating coil 5 (step S7), and cooking is started.

  While cooking is being performed, the temperature sensor 6 detects the temperature of the pan bottom of the cooking pan 4 and inputs a detection signal to the pan bottom temperature determining means 15. When the detected pot bottom temperature is equal to or higher than a predetermined temperature, a determination signal indicating that the temperature is equal to or higher than the predetermined temperature is output to the control unit 21. Then, the control unit 21 sends an instruction to reduce the output to some extent to the frequency generating unit 13 based on the determination signal indicating that the temperature is equal to or higher than the predetermined temperature of the pan bottom temperature determining unit 15. A drive signal for reducing the output is sent to reduce the output supplied to the heating coil 5. Therefore, the temperature at the bottom of the cooking pan 4 is maintained within a certain temperature.

Thus, cooking is continued while the temperature of the bottom of the cooking pan 4 is maintained within a certain temperature. For example, during cooking, the user operates the timer switch 2c to perform a desired cooking time (cooking). When the end time is set, the second timer 20 starts to operate (step S8).
The control unit 21 compares the timer time of the timer signal output from the first timer 19 with the timer time of the timer signal output from the second timer 20 and compares the first timer with respect to the timer time of the second timer 20. When the timer time of 19 is short, the timer time of the second timer 20 is prioritized. When the timer time of the first timer 19 is longer than the timer time of the second timer 20, the timer time of the second timer 20 is also selected. When the timer time of the second timer 20 elapses, the control unit 21 sends a command to stop the drive to the frequency generating means 13, so that the output to the heating coil 5 by the inverter circuit 12 is stopped and cooking is performed. The process ends (step S9).

Next, the operation of the magnetic flux modulation plate 7 will be described with reference to FIG. The magnetic flux modulation plate 7 acts when a high frequency current flows through the heating coil 5.
The magnetic flux modulation plate 7 generates an alternating magnetic field based on the direction of the high-frequency current flowing through the heating coil 5 when a high-frequency current flows through the heating coil 5 in a state where there is sufficient water 15 in the cooking pan 4. The cooking pan 4 facing the heating coil 5 is pushed out in the inner direction at the same frequency as the high frequency of the alternating magnetic field (FIG. 3A).

On the other hand, the high frequency of the alternating magnetic field generated from the heating coil 5 is reflected by the magnetic flux modulation plate 7 which is a nonmagnetic metal material. As a result, the surface of the cooking pan 4 facing the magnetic flux modulation plate 7 is pushed out to the outside of the cooking pan 4 at the same frequency as the high frequency of the alternating magnetic field ((B) in FIG. 3).
Therefore, when the frequency of the high frequency of the alternating magnetic field coincides with the natural frequency of the cooking pan 4, it resonates. That is, when it coincides with or near the resonance frequency of the cooking pan 4 or an integral multiple of the resonance frequency, the cooking pan 4 vibrates due to resonance by repeating the operations of (A) and (B) in FIG. An ultrasonic wave is generated in the water 15 in the cooking pan 4.

  As described above, according to the first embodiment, the inverter circuit 12 is driven so that the frequency generating means 13 supplies the high-frequency current to the heating coil 5 at the predetermined drive frequency set by the stew key 2b of the operation unit 2. Then, the driving frequency changing means 14 changes the driving frequency output from the frequency creating means 13, and the resonance frequency detecting means 16 detects the resonance frequency with the natural frequency of the cooking pan 4 based on the output of the vibration sensor 7. In this case, the control unit 21 outputs a command for outputting a high-frequency current having the resonance frequency detected by the resonance frequency detection unit 16 to the frequency generation unit 13, and the frequency generation unit 13 drives the inverter circuit 12 with a drive signal of the resonance frequency. The high frequency current of the resonance frequency is supplied to the heating coil 5 and the high frequency of the alternating magnetic field generated from the heating coil 5 is reflected above the heating coil 5. Since the modulation plate 8 is arranged, the alternating magnetic field generated in the heating coil 5 due to the high frequency current at the resonance frequency is reflected by the magnetic flux modulation plate 7 to cause the cooking pan 4 to generate high frequency vibration due to resonance at the resonance frequency, thereby cooking. Since ultrasonic waves can be generated in the water 15 in the pot 4, an ultrasonic transducer as in the conventional example is not required, an inverter circuit for driving the ultrasonic transducer can be eliminated, and cost reduction is achieved. Can be achieved.

In addition, the magnetic flux modulation plate 8, which is one of the means for generating ultrasonic waves even when spilled during cooking, is shielded by the top plate 3 and is located inside the cooker body 1. It will not wake up. Moreover, even if it is not the specific cooking pan 4, an ultrasonic vibration can be applied, it is possible to boil softly, without scorching a cooking thing.
In the first embodiment, a ring-shaped magnetic flux modulation plate 8 is disposed concentrically with respect to the center of the pan bottom between the top plate 3 and the heating coil 5. Even if a plurality of small magnetic flux modulation plates are arranged concentrically with the coil 5 at regular intervals with respect to the center of the pan bottom, the same effect as the ring-shaped magnetic flux modulation plate 8 is obtained.

Embodiment 2
FIG. 4 is a block diagram showing the configuration of the induction heating cooker according to Embodiment 2 of the present invention, and FIG. 5 is a flowchart showing the operation of the induction heating cooker.
In the figure, the same configurations as those of the first embodiment are denoted by the same reference numerals in the second embodiment, and the description of the duplicated configurations is omitted.
In the second embodiment, the operation unit 2 is provided with an output adjustment encoder switch 2d instead of the stew key 2b. When the encoder switch 2d for adjusting the output is pushed in a depressed state, the switch pops out to be in an ON state, and when pushed in the protruding state, the switch is depressed to be in an OFF state. The thermal power (output) becomes strong and can be set so that the thermal power (output) becomes weak when it rotates counterclockwise.

In addition, power control means 23 for controlling the power supplied to the heating coil 5 is provided. This power control means 23 outputs a drive signal of a drive frequency to the inverter circuit 12 so that an output in accordance with the heating power level set by the encoder switch 2c is output.
Further, in the second embodiment, an infrared sensor 16 is disposed immediately below the top plate 3 in place of the temperature sensor 6 of the first embodiment.

Next, the operation of the induction heater according to the second embodiment of the present invention will be described based on the flowcharts of FIGS. 4 and 5. In addition, since the effect | action of the magnetic flux modulation board 8 is the same as the said Embodiment 1, it abbreviate | omits here.
First, after placing the cooking pan 4 containing the object to be heated on the top plate 3 of the cooker body 1, the main switch 2a of the operation unit 2 is turned on and the power is turned on (step S11). . Thereafter, the encoder switch 2d for adjusting the output of the operation unit 2 is pushed and turned on, and the encoder switch 2d is further rotated to set a desired heating power (output) (step S12).
The process from the pot detection at the next step S13 to the resonance frequency detection at step S16 is the same as the process from the pot detection at step S3 of the first embodiment to the resonance frequency detection at step S6, and therefore description thereof is omitted.

Then, the control unit 2 instructs the frequency generating means 13 to drive the inverter circuit 13 at the resonance frequency, and instructs the power control means 23 to drive the inverter circuit 12 so that the heating power set by the encoder switch 2d in step S12 is obtained. And alternately.
As shown in FIG. 6, the inverter circuit 12 is alternately driven by the drive signal of the set thermal power drive frequency controlled by the power control means 23 and the drive signal of the resonance frequency controlled by the frequency generating means 13. Then, the set power and the high-frequency current having the resonance frequency are alternately supplied to the heating coil 5 (step S17), and cooking is started.

While cooking is being performed, the infrared sensor 16 detects the temperature of the bottom of the cooking pan 4 and inputs a detection signal to the pan bottom temperature determining means 15, and the infrared sensor 16 detects the pan bottom temperature determining means 15. When the cooked pan bottom temperature is equal to or higher than the predetermined temperature, a determination signal indicating that the temperature is equal to or higher than the predetermined temperature is output to the control unit 21.
Then, the control unit 21 sends an instruction to reduce the output to some extent to the frequency generating unit 13 based on the determination signal indicating that the temperature is equal to or higher than the predetermined temperature of the pan bottom temperature determining unit 15. The drive signal which reduces an output is sent and the output supplied to the heating coil 5 is reduced. Accordingly, the temperature at the bottom of the cooking pan 4 is maintained within a certain temperature.

Thus, cooking is continued while the temperature of the bottom of the cooking pan 4 is maintained within a certain temperature. For example, during cooking, the user operates the timer switch 2c to perform a desired cooking time (cooking). When the (end time) is set, the second timer 20 starts operating (step S18).
The control unit 21 compares the timer time of the timer signal output from the first timer 19 with the timer time of the timer signal output from the second timer 20 and compares the first timer with respect to the timer time of the second timer 20. When the timer time of 19 is short, the timer time of the second timer 20 is prioritized. When the timer time of the first timer 19 is longer than the timer time of the second timer 20, the timer time of the second timer 20 is also selected. When the timer time of the second timer 20 elapses, the control unit 21 sends a command to stop the drive to the frequency generating means 13, so that the output to the heating coil 5 by the inverter circuit 12 is stopped and cooking is performed. The process ends (step S19).

Even if the heating power is changed by operating the encoder switch 2d for output adjustment, the resonance frequency in the frequency generating means 14 is maintained only by changing the numerical value by the power control means 23 so as to become the set heating power. .

In the second embodiment, substantially the same effect as in the first embodiment can be obtained, and when the encoder switch 2d for output adjustment is operated and set to various heating powers, the control unit 21 connects the encoder to the power control means 23. A command for driving the inverter circuit 12 so as to achieve the thermal power set by the switch 2c and a command for driving the inverter circuit 13 at the resonance frequency are alternately sent to the frequency generating means 13, and the inverter circuit 12 is supplied with power by the power control means 23. Driven alternately by the drive signal of the controlled setting thermal power drive frequency and the drive signal of the resonance frequency controlled by the frequency generating means 13, the set power and the high frequency current of the resonance frequency are alternately supplied to the heating coil 5. Since it is supplied and cooked, various settings of the thermal power level are possible, and special equipment keys such as stew Also enables the application of ultrasound in the outside, a wide range of cooking to be applying ultrasonic waves, it is possible to delicious cooking.

  Further, the temperature sensor 6 of the first embodiment indirectly measures the temperature of the bottom of the cooking pan 4 via the top plate 3, but the infrared sensor 16 of the second embodiment is used for cooking. Since the temperature at the bottom of the pot 4 can be directly measured, the temperature at the bottom of the pot can be grasped more accurately, and temperature management with higher accuracy than that of the first embodiment is possible.

Embodiment 3
FIG. 7 is a block diagram showing a configuration of an induction heating cooker according to Embodiment 3 of the present invention.
In the figure, the same configurations as those of the second embodiment are denoted by the same reference numerals in the third embodiment, and the description of the duplicated configurations is omitted.
In the third embodiment, the operation unit 2 is provided with a first memory key 2e and a second memory key 2f for registering and calling the resonance frequency of each cooking pan 4. Further, the memory 25 stores the resonance frequency of each cooking pan 4 when, for example, two types of cooking pans 4 are used.

First, after the user places the first cooking pan 4 on the top plate 3, the main switch 2a of the operation unit 2 is turned on to turn on the power, and then the output adjustment encoder of the operation unit 2 is turned on. The switch 2c is pushed and turned ON, and the encoder switch 2c is further rotated to set a desired heating power (output), and the first memory key 2e is set to registration.
Then, as in the second embodiment, the procedure from the pan detection in step S3 to the resonance frequency detection in step S6 is executed. And since the 1st memory key 2e is set to registration, the control part 21 memorize | stores the resonant frequency which the resonant frequency detection means 16 detected about the 1st cooking pot 4 in the memory 25, and registration is completed. .
Thereafter, the procedure from the power control + frequency control in step S7 to the completion of cooking in step S19 is executed.

  Next, when the user registers the resonance frequency of the second cooking pan 4 in the memory 25, the main switch 2a of the operation unit 2 is turned on as in the case of the first cooking pan 4. After turning on the power, the encoder switch 2c for adjusting the output of the operation unit 2 is pushed and turned on, and further, the encoder switch 2c is rotated to set a desired heating power (output), and the second memory key 2f is set. By setting the registration, the resonance frequency detected by the resonance frequency detecting means 16 for the second cooking pan 4 is stored in the memory 25 in the same procedure as the first cooking pan 4 and the registration is completed. .

  When registration of the resonance frequencies of the first and second cooking pans 4 in the memory 25 is completed in this way, the next time the first cooking pan 4 is used for heating cooking, The switch 2a is turned on and the power is turned on. Thereafter, the encoder switch 2c for adjusting the output of the operation unit 2 is pushed and turned on. Further, the encoder switch 2c is rotated to set a desired heating power (output). By setting the memory key 2e of 1 to call, the resonance frequency of the first cooking pan 4 is called from the memory 25 and enters the power control + frequency control which is the next step S19. Or the resonance frequency detection procedure of step S16 performed by operating the resonance frequency detection means 16 can be excluded, and stable ultrasonic cooking can be immediately started, and it can be easily burnt. It is good food not.

  In Embodiment 3 mentioned above, since there are two types of cooking pots 4, the first and second memory keys 2 e and 2 f are provided in the operation unit 2, but there are a plurality of types of cooking pots 4. In this case, it is needless to say that a plurality of memory keys may be provided in the operation unit 2.

The block diagram which shows the structure of the induction heating cooking appliance which concerns on Embodiment 1 of this invention. The flowchart which shows operation | movement of the same induction heating cooking appliance. The work schematic diagram of the alternating magnetic field at the time of the electromagnetic induction heating of the induction heating cooking appliance. The block diagram which shows the structure of the induction heating cooking appliance which concerns on Embodiment 2 of this invention. The flowchart which shows operation | movement of the same induction heating cooking appliance. The graph which shows the state of the thermal power control of the induction heating cooking appliance. The block diagram which shows the structure of the induction heating cooking appliance which concerns on Embodiment 3 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cooker main body, 2 Operation part, 2a Main switch, 2b Stew key, 3 Top plate, 4 Cooking pan, 5 Heating coil, 6 Temperature sensor, 7 Vibration sensor, 8 Magnetic flux modulation board, 10 AC power supply, 11 Rectification circuit , 12 Inverter circuit, 13 Frequency creating means, 14 Drive frequency changing means, 15 Pan bottom temperature judging means, 16 Resonance frequency detecting means, 17 Pan discriminating means, 18 Lamp (abnormality notifying means), 19 First timer, 20 Second Timer, 21 control unit.

Claims (5)

A rectifier circuit for rectifying the current from the AC power supply;
An inverter circuit connected to the output side of the rectifier circuit and converting a current into a high-frequency current;
A heating coil that is connected to the output side of the inverter circuit and is supplied with high-frequency current to inductively heat the cooking pan;
A magnetic flux modulation plate that is disposed above the heating coil and reflects a high frequency of an alternating magnetic field generated from the heating coil;
Drive frequency control means for outputting a drive signal for changing the drive frequency to detect the resonance frequency at which the cooking pan resonates, to the inverter circuit;
A vibration sensor for detecting the vibration of the cooking pan;
Resonance frequency detection means for detecting a resonance frequency at which the cooking pan resonates based on the output of the vibration sensor in a state where the drive frequency of the drive signal is changed,
An induction heating cooker including a control unit that outputs a resonance frequency detected by the resonance frequency detection means or a drive signal of an integral multiple thereof from the drive frequency control unit,
An output adjustment encoder switch that is provided in the operation unit and adjusts the thermal power;
Power control means for outputting to the inverter a drive signal having a drive frequency such that the heating power set by the encoder switch for output adjustment is obtained,
The control unit gives a command to drive the inverter circuit so that the power control means has a heating power set by the encoder switch for output adjustment, and a command to drive the inverter circuit at a resonance frequency to the drive frequency control means. Send alternately,
The inverter circuit is driven alternately by the drive signal of the drive frequency of the set fired power controlled from the power control means and the drive signal of the resonance frequency from the drive frequency control means or an integral multiple thereof. Induction heating cooker characterized by. A pan discriminating means for determining whether or not the cooking pan is present and whether it is a proper cooking pan, and an abnormality notification means for displaying an abnormality indicating that there is no cooking pan or is not a proper cooking pan,
The control unit has no cooking pan determined by the pan determining means or an abnormal determination signal indicating that the cooking pan is not an appropriate cooking pan, and the abnormality notifying means has no cooking pan or an appropriate cooking pan. The induction heating cooker according to claim 1, wherein the abnormality is notified. A temperature sensor for detecting the pan bottom temperature of the cooking pan; and a pan bottom temperature determining means for determining that the pan bottom temperature detected by the temperature sensor is equal to or higher than a predetermined temperature.
2. The control unit according to claim 1, wherein the driving frequency control unit causes the driving frequency control unit to output a driving signal for reducing the output based on a determination signal determined by the pan bottom temperature determining means to determine that the pan bottom temperature is equal to or higher than a predetermined temperature. Or the induction heating cooking appliance of 2. There is a cooking pan determined by the pan determination means, and a timer signal that starts operation based on a determination signal indicating that the pan is an appropriate cooking pan and outputs a predetermined drive signal is output to the control unit for a predetermined timer time A first timer to
A timer switch for setting a predetermined cooking time, and a second timer for outputting a timer signal that operates during the cooking time set by the timer switch and outputs a predetermined driving signal to the control unit,
The control unit receives the timer signal of the first timer, drives the drive frequency control means by a predetermined drive signal, and receives the timer signal of the second timer during the predetermined timer time of the first timer. If not, stop driving of the drive frequency control means at the end of the timer time of the first timer ,
When the timer signal of the second timer is received during the predetermined timer time of the first timer, the timer of the second timer continues to drive the drive frequency control means by the timer signal of the first timer. based on the signals by driving the drive frequency control means by a predetermined drive signal, according to claim 2, characterized in that the timer time of the second timer so as to stop the driving of the drive frequency control means at the end The induction heating cooker described.   A memory for storing a resonance frequency according to the type of the cooking pan detected by the resonance frequency detection means or an integer multiple thereof, and a resonance frequency according to the type of the cooking pan stored in the memory or an integer multiple thereof An induction heating cooker according to any one of claims 1 to 4, further comprising a memory key that calls and sends the key to the control unit.

Images