JP4864850B2 - Induction heating cooker - Google Patents

Description

  The present invention relates to an induction heating cooker that efficiently heats regardless of the size of a cooking container such as a pan by using a plurality of induction heating coils.

  A conventional induction heating cooker has a small-diameter induction heating coil provided inside and a concentric circle with the small-diameter induction heating coil, and the large-diameter induction heating coil provided on the outside has a large and small diameter for the cooking vessel. Accordingly, only the inner induction heating coil or both the inner and outer induction heating coils are driven by a full-bridge inverter circuit to efficiently perform heating regardless of the size of the cooking container (for example, Patent Documents). 1).

Japanese Patent No. 3687028 (FIGS. 1 and 3, columns 4 to 16)

  The induction heating coil in the conventional induction heating cooker has a constant coil diameter through which a high-frequency current flows regardless of the pot diameter of the cooking container. For this reason, in a cooking container (pan) whose diameter is smaller than the diameter of the induction heating coil, there is a problem that the magnetic flux generated by the current flowing in the coil outside the diameter of the bottom of the pot does not contribute to heating and the efficiency is reduced. There was a problem that the magnetic flux leaked from the coil part not covered with. The induction heating cooker of Patent Document 1 includes an independent small-diameter induction heating coil and a large-diameter induction heating coil so that the energization state of the two induction heating coils is switched according to the diameter of a cooking container such as a pan. Heating according to the pan diameter is possible. However, the place where the pan is placed needs to be installed in the vicinity of the center with respect to the heating port, and the number of pans that can be placed is one for each heating port.

This invention was made in order to solve the above problems, and a first object is to provide an induction heating apparatus that improves the degree of freedom related to the place and number of pots in a specific heating port. There is to get.
The second purpose is to perform optimum driving according to the cooking container, to suppress interference caused by electromagnetic waves emitted from a plurality of spiral coil elements, to efficiently heat, and to minimize leakage magnetic flux. It is to obtain a heating device.

In order to achieve the above object, an induction heating cooker according to the present invention includes a top plate on which a plurality of heating ports indicating positions where cooking containers such as pans are placed, and a plurality of heating ports. An induction heating coil that is arranged directly below and heats the cooking container, a high frequency power supply unit that drives each of the induction heating coils, and a control circuit that controls the high frequency power supply unit. A plurality of induction heating coils having a diameter smaller than the diameter of one induction heating coil arranged immediately below the second heating port and having a diameter substantially the same as that of the first heating port The high frequency power supply is arranged so that the plurality of induction heating coils arranged immediately below the first heating port are sequentially energized and de-energized at regular intervals. which was equipped with a cooking mode for controlling the parts That.

  According to the present invention, among the plurality of heating ports, a plurality of induction heatings having a diameter smaller than the diameter of one induction heating coil disposed immediately below the first heating port and immediately below the second heating port. Since the coils were evenly distributed in a region having the same diameter as that of the first heating port, the degree of freedom regarding the place and number of the pots was improved.

Embodiment 1 FIG.
FIG. 1 is a top view of an induction heating apparatus showing Embodiment 1 of the present invention. Reference numeral 1 denotes a heat-resistant top plate on which the pan is placed, and has a total of three heating ports including a left heating port 2, a right heating port 3, and a central heating port 4. One induction heating coil 5 is installed at the lower part of the central heating port 4, and one pot placed on the upper part of the central heating port 4 is induction heated by a high frequency magnetic field generated from the induction heating coil 5. Similarly, one induction heating coil 6 is installed in the lower part of the right heating port 3, and one pot placed on the right heating port 3 is induction heated. Three induction heating coils of an induction heating coil 7, an induction heating coil 8, and an induction heating coil 9 are installed below the left heating port 2, and a plurality of pans placed on the top plate are induction heated. A display / operation unit 10 includes an operation switch, a liquid crystal panel, and the like. The user adjusts the heating power by selecting the switch, selects a heating port, and the like, and displays a heating state on the liquid crystal panel.

  FIG. 2 is a configuration diagram showing a drive circuit for the left heating port of the induction heating apparatus according to Embodiment 1 of the present invention. In the figure, a commercial AC power source 51, a power fuse 52, a power supply unit comprising a capacitor 53 connected in parallel to the commercial AC power source 51, and a rectifier circuit 54, a filter 55, a capacitor 67 for smoothing a DC voltage, and two pieces Switching elements 56 and 57, 58 and 59, and 60 and 61 are connected in series, and a high frequency power supply unit including three arms is provided. The six switching elements 56, 57, 58, 59, 60, 61 are configured to be built in one power module 66. The power module 66 constitutes a high frequency power supply unit. Each of the switching elements 56-57, 58-59, and 60-61 constitutes a half-bridge inverter circuit, and the induction heating coil 7 and the resonant capacitor 62 are connected in series between the output point and the ground. A resonance circuit, a series resonance circuit of the induction heating coil 8 and the resonance capacitor 63, and a series resonance circuit of the induction heating coil 9 and the resonance capacitor 64 are connected. The control circuit 65 controls energization of the switching elements 56, 57, 58, 59, 60, 61 according to the operation of the operation / display unit 10 by the user.

FIG. 3 is a diagram showing the structure of the induction heating coils 7, 8 and 9 constituting the left heating port of the induction heating apparatus in Embodiment 1 of the present invention, and these three induction heating coils are made of the same material and the same. The shape is the same diameter. The induction heating coils 7, 8, and 9 are constituted by a coil base 11 that supports the coil and a coil 12 in which a copper wire is uniformly wound. The coil is concentrically wound with a diameter of about 90 mm and has a three-stage structure. Moreover, the temperature sensor 100 which detects the temperature of a pan bottom via the top plate is arrange | positioned in the center part of the coil 12. FIG. The temperature sensor 100 is a thermistor whose resistance value changes with temperature, for example. A detection signal of the temperature sensor 100 is input to the control circuit 65.
In addition, although the horizontal cross-sectional shape of said induction heating coil is substantially circular, not only this but a substantially regular polygon may be sufficient, and the effect obtained is the same as that of the case of a substantially circular shape.

  Operation | movement of the induction heating cooking appliance of Embodiment 1 is demonstrated. When a user places a pan on the left heating port 2 on the top plate 1 and starts cooking by operating the operation / display unit 10, the pan is connected to the induction heating coils 7, 8, and 9 in series. The presence / absence of a pan immediately above each induction heating coil is determined from the coil current detection value by a current transformer or the like (not shown). When a pot having a diameter that covers all the induction heating coils 7, 8, and 9 constituting the left heating port 2 is placed, induction is performed using all the induction heating coils that constitute the left heating port 2. Heating is performed. When the heating operation is started, the AC power input from the commercial power source 51 is converted into DC power by the rectifier 54, the choke coil 55, and the smoothing capacitor 67, and is supplied to the high frequency power source unit (power module) 66. The high frequency power supply unit 66 converts DC power into high frequency power of 20 kHz and supplies it to each induction heating coil by the switching operation of the switching element.

  FIG. 4 is a diagram showing an energized state of the induction heating coils 7, 8, and 9 constituting the left heating port of the induction heating device in the first embodiment. FIG. 5 is a diagram showing a waveform of a current flowing through the induction heating coil of the left heating port of the induction heating apparatus in the first embodiment. The induction heating coils 7, 8, and 9 are all wound in the same direction with respect to the output point of the inverter, and are controlled by the control circuit 65 so that currents having the same frequency and the same phase flow. Therefore, the direction of the high frequency magnetic field generated from the induction heating coils 7, 8 and 9 is controlled to be always the same. The bottom of the pan is induction heated by the high frequency magnetic field generated from the induction heating coil, and cooking is performed.

  In addition, a temperature sensor 100 for detecting the temperature of the pan bottom is installed at the center of each induction heating coil 7, 8 and 9, and the control circuit 65 is placed via the top plate 1 at regular intervals. It detects the temperature at each point on the bottom of the pan. When a part where the temperature has been locally lowered due to the input of food is detected, the control circuit 65 increases the energization ratio to the induction heating coil at the part where the temperature is lowered by PWM control, thereby increasing the amount of heating at that part. Control to keep the temperature at the bottom of the pan uniform.

  After cooking, when the heating stop operation is executed by the operation of the display / operation unit 10 by the user, the control circuit 65 stops the control signals of the switching elements 56, 57, 58, 59, 60, 61, Stop the coil current.

Moreover, FIG. 6 is a figure which shows another electric current waveform which flows into the induction heating coil of the left heating port of the induction heating apparatus in Embodiment 1. FIG. The configuration of the induction heating coil is the same as that shown in FIG. Here, the frequency and phase of the current flowing through each induction heating coil are the same, but the current is periodically thinned out. That is, as shown in FIG. 6, when the current is applied for one period, the energization is stopped for the next period. Thereby, the same cooking effect can be produced.
Needless to say, the thinning cycle is not limited to 1: 1, but can be set freely according to the cooking environment, such as 1: 2 or 1: 3. For example, as shown in FIG. 7, half-cycles may be thinned out. In this case, the same effect can be obtained.
Furthermore, as shown in FIG. 8, if the phases match, waveforms having different periods may be mixed within a range where interference does not occur. In this case, the same effect can be obtained by averaging over a long time.
Furthermore, as shown in FIG. 9, the energization time of the induction heating coil 7, the energization time of the induction heating coil 8, and the energization time of the induction heating coil 9 may be shifted by one period. That is, the energization of the induction heating coil 8 and the induction heating coil 9 is stopped during the energization time of the induction heating coil 7, and the energization of the induction heating coil 9 and the induction heating coil 7 is stopped during the energization time of the induction heating coil 8. During the energization time of the induction heating coil 9, the energization of the induction heating coil 7 and the induction heating coil 8 is stopped. Further, this cycle may be thinned out in the same manner as described above. Both have the same effects as described above.

  FIG. 10 is a diagram showing an oval pan placement state of the induction heating device according to Embodiment 1 of the present invention. FIG. 11 is a current waveform diagram of the induction heating coil in the oval pan mounting state of FIG. Operation | movement of the induction heating apparatus which shows Embodiment 1 in an oval pan mounting state is demonstrated.

  As shown in FIG. 10, it is assumed that an elliptical oval pan is placed on the induction heating coils 7 and 9 by the user in the left heating port 2 on the top plate 1. When cooking is started by the user's operation, the presence or absence of a cooking container immediately above the induction heating coil is determined by a pan detection means (not shown) such as a current transformer installed in each induction heating coil. When the control circuit 65 detects that there is a pan on the induction heating coils 7 and 9, as shown in FIG. 11, only the induction heating coils 7 and 9 are energized and controlled, and the induction heating without a pan immediately above the induction heating coil is performed. The coil 8 is controlled not to be energized. Since the currents of the induction heating coils 7 and 9 to be energized are controlled by the control circuit 65 so as to have the same frequency and the same phase, the high frequency magnetic field generated from the induction heating coils 7 and 9 to the pan is always the same. Direction. When the heating stop operation is executed by the operation of the display / operation unit 10 by the user, the control circuit 65 stops driving the switching elements 56, 57, 60, 61 and stops the heating operation of the pan.

  As shown in FIG. 12, it is assumed that a kettle is placed on the induction heating coil 8 by the user in the left heating port 2 on the top plate 1. When cooking is started by the user's operation, the presence or absence of a cooking container on the induction heating coil is determined by a pan detection means (not shown) such as a current transformer installed in each induction heating coil. When the control circuit 65 detects that the pan is placed only on the induction heating coil 8, as shown in FIG. 13, only the induction heating coil 8 is energized and the induction heating coil is not directly above the induction heating coil. Control is performed so that the coils 7 and 9 are not energized. When the heating stop operation is executed by the operation of the operation / display unit 10 by the user, the control circuit 65 stops driving the switching elements 58 and 59 to stop the heating operation of the pan. Similarly, when two or three kettles having the same diameter as one induction heating coil are mounted, the plurality of pots are heated by energizing only the induction heating coil at the mounting site.

  FIG. 14 is a diagram showing the relationship between the number of induction heating coils in the energized state of the induction heating device and the current upper limit value according to Embodiment 1 of the present invention. The induction heating coil current upper limit value at the maximum heating power is determined as shown in FIG. 14, and the current upper limit value is set larger as the number of the induction heating coils in the energized state is smaller. As described above, the induction heating coils 7, 8, and 9 are mixed in the energized state and the inactive state depending on the mounting state of the pan. When all the induction heating coils 7, 8, and 9 are energized, the combined current of the three coils is input to the DC power supply circuit including the rectifier 54, the choke coil 55, and the power module 66. As a result, the Joule loss in the electric parts and the current path becomes excessive. On the other hand, when a small pan such as a kettle is placed, only one induction heating coil is energized, so a DC power supply circuit composed of a rectifier 54, a choke coil 55, etc., and an input section of the module 66 In this case, a current corresponding to one coil flows, so that heat generation due to Joule loss is reduced, and a burden on circuit components is reduced. As described above, since the input current decreases as the number of induction heating coils in the energized state decreases, the current upper limit value per piece is set to increase as the number of induction heating coils being driven decreases.

  With the above configuration, by providing a plurality of independent induction heating coils for one heating port, it becomes possible to perform heating according to the size of the pan, reducing leakage magnetic flux and improving heating efficiency. Can be planned. In addition, by providing a plurality of induction heating coils, it is possible to control the temperature of the pan bottom with high accuracy by centralized heating of the temperature lowering portion. Also, as the number of induction heating coils in the energized state increases, the current upper limit value per induction heating coil is reduced, so there is no need to increase the current rating of the electrical components of the DC power supply section, and heat generation due to the current is prevented. Since it can reduce, size reduction of cooling systems, such as a heat radiating fan and a fin, can be achieved. Further, by controlling the current frequency and phase of the induction heating coils in the energized state to be the same, it is possible to suppress a decrease in magnetic flux due to interference of high-frequency magnetic fields generated from the induction heating coils. Further, by stacking a plurality of coils, a large inductance can be obtained with a small winding diameter. Moreover, it is possible to heat a some pan simultaneously by providing the some induction heating coil. In the present embodiment, the high frequency power supply unit is all built in one module, but may be configured by using a plurality of discrete switching elements.

Embodiment 2. FIG.
Next, an induction heating cooker according to Embodiment 2 will be described. FIG. 1 is also applied to the second embodiment. Explanations and drawings are omitted for the same points as in the first embodiment. FIG. 15 is a diagram illustrating an energization state of the induction heating coil. In FIG. 15, the current waveform of each coil is assumed to indicate an energized state and an off state to indicate a stopped state.

  Operation | movement of the induction heating cooking appliance of Embodiment 1 is demonstrated. It is assumed that a pan having a diameter that covers all the induction heating coils 7, 8, and 9 is placed on the left heating port 2 on the top plate 1 by the user. When the cooked cooking mode is selected by the operation of the operation / display unit 10 by the user and cooking is started, the current transformer connected to each induction heating coil 7, 8, and 9 as in the first embodiment. The presence / absence of a pan directly above the coil is determined from a current detection value obtained by a method such as (not shown). When it is detected that the pan is placed on the coils 7, 8, and 9, the stewed cooking mode is performed according to a sequence stored in advance in the control circuit 65 using all induction heating coils constituting the left heating port 2. Is executed.

  As shown in FIG. 15, when the stew cooking mode is started, the energized state and the non-energized state of the induction heating coils 7, 8 and 9 are controlled to change at intervals of 5 seconds. For 5 seconds after cooking is started, only the induction heating coil 7 is energized, for 5-10 seconds after cooking is started, only the induction heating coil 8 is controlled for energization, and for 10-15 seconds after cooking is started, only the induction heating coil 9 is energized. The induction heating coils 7, 8, and 9 are all controlled to be energized for 15-20 seconds after the start of cooking. In the stew mode, the above sequence is repeatedly controlled until the user's stop operation is executed.

  With the above configuration, the energized state and the non-energized state are controlled at regular intervals, and the number of energized induction heating coils is controlled to increase or decrease at regular intervals. Then, temperature unevenness occurs at regular intervals, and the mixing effect by convection of the contents can be obtained.

Embodiment 3 FIG.
Next, an induction heating cooker according to Embodiment 3 will be described. Note that the description and illustration of the same points as in the first embodiment are omitted. FIG. 16 is a diagram showing an arrangement state of the induction heating coil of the left heating port in the third embodiment of the present invention. In FIG. 16, reference numerals 80, 81, 82, 83, 84, and 85 denote induction heating coils, all having the same shape as in the first embodiment. FIG. 17 is a block diagram showing a left heating port driving circuit according to Embodiment 3 of the present invention. 17 differs from FIG. 1 in that a high-frequency power source module 70 composed of switching elements 71, 72, 73, 74, 75, and 76 is connected in parallel to a module 66 at the output point of the DC power supply circuit. , Switching element 71-72, switching element 73-74, switching element 75-76, respectively, between the output point of the half-bridge inverter and the ground, a series resonance circuit of induction heating coil 83 and resonance capacitor 77, induction heating, respectively. The series resonance circuit of the coil 84 and the resonance capacitor 78 and the series resonance circuit of the induction heating coil 85 and the resonance capacitor 79 are connected.

  Operation | movement of the induction heating cooking appliance of Embodiment 3 is demonstrated. When a pan is placed in the left heating port 2 on the top plate 1 and cooking is started by the operation / display unit 10 by the user, a current transformer or the like connected to each induction heating coil (not shown) ), The control circuit 65 determines whether or not a pan is placed immediately above each induction heating coil. The induction heating coil in which the pan placement is detected is energized and controlled by the control circuit 65. As in the first embodiment, the phase and frequency of all the induction heating coils in the energized state are controlled to be the same. Therefore, the high frequency magnetic field generated from each induction heating coil is restrained from influences such as cancellation of magnetic flux due to interference. The

  Further, at the center of each induction heating coil 80, 81, 82, 83, 84 and 85, a temperature sensor 100 for detecting the temperature of the pan bottom is installed at the center of each induction heating coil as shown in FIG. The control circuit 65 detects the temperature of the pan bottom placed via the top plate 1 at regular intervals. When detecting a part where the temperature has dropped locally due to the input of food, etc., the control circuit 65 uses PWM control to increase the energization ratio to the induction heating coil at the part where the temperature drop has been detected, thereby increasing the amount of heating at that part. I do.

  Moreover, when the stew mode is selected by the user, as in the second embodiment, the induction heating coils in the energized state and the non-energized state are switched at regular intervals, and the number of the induction heating coils in the energized state is also set. By changing the temperature, it is possible to intentionally create temperature unevenness in the bottom of the stewed cooking pan, thereby achieving a mixing effect by convection.

  Although not shown, the direction of convection may be changed in time division by changing the direction of the drive current of all induction heating coils in time division. For example, the control circuit 65 controls the high frequency power supply unit 66 so as to change the direction of the drive current of the induction heating coil in units of several minutes. Thereby, the temperature nonuniformity in a pan container is suppressed and favorable cooking is attained.

  With the above configuration, the number of induction heating coils is increased as compared to the first embodiment, so that a variety of heating patterns can be produced during stewed cooking. Moreover, since the induction heating coil is arrange | positioned without gap compared with Embodiment 1, it is possible to heat the whole surface of the mounted pan. Further, since the number of induction heating coils is increased as compared with the first embodiment, it is possible to control the temperature of the pan bottom with higher accuracy. In addition, since the number of high frequency power supply modules is two, the current and heat generation per module can be reduced, so that the reliability is improved.

Embodiment 4 FIG.
In the fourth embodiment, when a cooking container made of a magnetic material is placed on the induction heating coil, the leakage magnetic flux is minimized and moved to the position where the heating efficiency is maximized by using the attractive force due to the magnetic lines. A form is demonstrated. Next, an induction heating cooker according to Embodiment 4 will be described. The configuration of FIG. 1 is also applied to the fourth embodiment. When a cook places a cooking container such as a pan on a heating port corresponding to a plurality of induction heating coils of the top plate, generally the cooking container is not necessarily placed at an optimal position. In addition, during cooking, the pan may vibrate due to thermal motion and shift from the optimal placement position.
Therefore, the control means 65 detects the center position where the cooking vessel (pan) is placed and the diameter of the pan based on the change in the current flowing through the plurality of induction heating coils during energization of the plurality of induction heating coils. . Based on the detected center position, the nearest optimum center position is calculated. In this case, one or more induction heating coils to be energized are identified from the induction heating coils arranged immediately below from the diameter of the pan and the current placement position, and the arrangement state of the identified induction heating coils (usually normal) These center positions are calculated on the basis of (uniformly arranged). Then, the deviation between the calculated center position of the optimum pan on the heating port and the current center position of the pan is estimated, and one or more induction heating coils to be energized are selected so that the deviation approaches zero. Further, the magnitude of the current flowing through each of the selected induction heating coils is calculated. And the high frequency power supply part 66 is controlled so that the calculated electric current may be supplied with respect to the selected induction heating coil.

FIG. 18 is a flowchart showing the operation of the control circuit in the fourth embodiment of the present invention.
Next, the operation will be described with reference to FIG.
The control circuit 65 energizes all the induction heating coils at the heating ports corresponding to the plurality of induction heating coils, and detects the respective current values (step S181). And based on the detected electric current value, it is determined whether the cooking container is mounted immediately above. And the center position and diameter of a cooking container are estimated (step S182). Next, based on the center position and diameter of the cooking container, the center position of the cooking container that is optimal in terms of heating efficiency is estimated by calculation (step S183). Next, the deviation between the optimum center position and the current center position is calculated, and at least one induction heating coil to be energized is selected in order to bring the pan position to the optimum position, and the induction heating coils are caused to flow. A current value is calculated (step S184). Next, the high frequency power supply unit is controlled so that the calculated current flows through the selected induction heating coil (step S185).
With the above operation, according to the fourth embodiment, the heating efficiency of the induction heating coil is improved and energy saving can be realized. In this case, as the induction heating coil is smaller in size and larger in number, the heating efficiency is improved and the energy saving effect is increased.

  In addition, when the material of the cooking container is a non-magnetic material such as aluminum or copper, it is not possible to use the attractive force due to the lines of magnetic force, but when there is no object to be cooked, it is lightweight because of the aluminum material. And the repulsive force from the induction heating coil is used to float the cooking container, and separately pass different currents to one or more induction heating coils arranged directly under and around the cooking container. Using the repulsive force from the induction heating coil, the cooking container can be moved to the optimum position in the same manner as described above. In this case, the same effect can be obtained.

It is an induction heating apparatus which shows Embodiment 1 of this invention. It is a block diagram which shows the drive circuit of the left heating port of the induction heating apparatus in Embodiment 1 of this invention. It is a figure which shows the structure of the induction heating coil of the induction heating apparatus in Embodiment 1 of this invention. It is a figure which shows the electricity supply state of the induction heating coil of the induction heating apparatus in Embodiment 1 of this invention. It is a figure which shows the electric current waveform of the induction heating coil of the induction heating apparatus in Embodiment 1 of this invention. It is a figure which shows another current waveform of the induction heating coil of the induction heating apparatus in Embodiment 1 of this invention. It is a figure which shows another current waveform of the induction heating coil of the induction heating apparatus in Embodiment 1 of this invention. It is a figure which shows another current waveform of the induction heating coil of the induction heating apparatus in Embodiment 1 of this invention. It is a figure which shows another current waveform of the induction heating coil of the induction heating apparatus in Embodiment 1 of this invention. It is a figure which shows the oval pan mounting state of the induction heating apparatus in Embodiment 1 of this invention. It is an electric current waveform diagram of the induction heating coil in the oval pan mounting state of FIG. It is a figure which shows the kettle mounting state of the induction heating apparatus in Embodiment 1 of this invention. FIG. 13 is a current waveform diagram of the induction heating coil in the kettle placement state of the induction heating device of FIG. 12. It is a figure which shows the relationship between the induction heating coil number of the electricity supply state of the induction heating apparatus in Embodiment 1 of this invention, and an electric current upper limit. It is a figure which shows the electricity supply state of the induction heating coil in Embodiment 2 of this invention. It is a figure which shows the arrangement | positioning state of the induction heating coil of the left heating port in Embodiment 3 of this invention. It is a block diagram which shows the drive circuit of the left heating port which concerns on Embodiment 3 of this invention. It is a flowchart which shows operation | movement of the control circuit in Embodiment 4 of this invention.

Explanation of symbols

  1 top plate, 2 left heating port, 3 right heating port, 4 central heating port, 5 induction heating coil, 6 induction heating coil, 7 induction heating coil, 8 induction heating coil, 9 induction heating coil, 10 display / operation unit, 11 Coil Base, 12 Coil, 13 Oval Pan, 14 Kettle, 51 Commercial AC Power Supply, 52 Fuse, 53 Capacitor, 54 Diode Bridge, 55 Choke Coil, 56, 57, 58, 59, 60, 61 Switching Element, 62, 63 , 64 resonant capacitor, 65 control circuit, 66 high frequency power supply (power module), 67 smoothing capacitor, 70 power module, 71, 72, 73, 74, 75, 76 switching element, 77, 78, 79 resonant capacitor, 80 81, 82, 83, 84, 85 induction heating coil, 00 temperature sensor.

Claims (12)

A top board on which a plurality of heating ports indicating positions where cooking containers such as pans are placed are displayed;
An induction heating coil that is disposed directly below each of the plurality of heating ports and that heats the cooking vessel;
A high frequency power supply for driving each of the induction heating coils;
A control circuit for controlling the high-frequency power supply unit,
Among the plurality of heating ports, a plurality of induction heating coils having a diameter smaller than the diameter of one induction heating coil disposed immediately below the first heating port and directly below the second heating port are the first heating port. evenly distributed in the area with a diameter of the heating port and the substantially the same,
The control circuit includes a cooking mode for controlling the high-frequency power supply unit so that a plurality of induction heating coils arranged immediately below the first heating port are sequentially energized and de-energized at regular intervals. An induction heating cooker characterized by that.   2. The induction heating cooker according to claim 1, wherein the control circuit controls the high-frequency power supply unit so that each of the induction heating coils is individually energized in a heating port including a plurality of induction heating coils. . 3. The induction heating according to claim 2, wherein the control circuit controls the high-frequency power supply unit to energize each of the induction heating coils arranged immediately below the first heating port at the same frequency. Cooking device. The control circuit energizes each of the induction heating coils arranged immediately below the first heating port in the same phase and controls the high-frequency power supply unit so that the directions of the high-frequency magnetic field with respect to the cooking container are the same. The induction heating cooker according to claim 3, wherein: The control circuit is configured such that the energization of each of the induction heating coils disposed immediately below the first heating port is periodically thinned so that the total energization amount per predetermined time is substantially the same. The induction heating cooker according to any one of claims 2 to 4, wherein the part is controlled. Before SL control circuit among the plurality of induction heating coils disposed immediately below the first heat opening based on the current flowing through each of the induction heating coil, and detects the number of induction heating coil energized state, this 6. The high-frequency power supply unit is controlled such that an upper limit value of a current flowing through each of the induction heating coils increases as the number of induction heating coils in an energized state decreases . Induction heating cooker. Before SL control circuit of said first plurality of induction heating coils disposed directly under the heating port based on the current flowing through each of the induction heating coil, induction cooking vessel just above is not placed The induction heating cooker according to any one of claims 1 to 6 , wherein a heating coil is specified and the high-frequency power supply unit is controlled so as not to energize the specified induction heating coil. Before Symbol induction heating coil, wherein the cooking mode, the induction heating cooking according to any of claims 1 to 7, characterized in that it is controlled so that the number of induction heating coil energized state at regular intervals increases or decreases vessel. The induction heating cooker according to any one of claims 1 to 8 , wherein the winding of the induction heating coil includes a plurality of stacked layers. The induction heating cooker according to any one of claims 1 to 9 , wherein the high-frequency power supply unit is a half-bridge inverter circuit in which two switching elements are connected in series. The induction heating cooker according to any one of claims 1 to 10 , wherein a shape of a horizontal cross section of the induction heating coil is substantially polygonal or substantially circular. A top board on which a plurality of heating ports indicating positions where cooking containers such as pans are placed are displayed;
An induction heating coil that is disposed directly below each of the plurality of heating ports and that heats the cooking vessel;
A high frequency power supply for driving each of the induction heating coils;
A control circuit for controlling the high-frequency power supply unit,
Among the plurality of heating ports, a plurality of induction heating coils having a diameter smaller than the diameter of one induction heating coil disposed immediately below the first heating port and directly below the second heating port are the first heating port. Distribute evenly in an area having the same diameter as the heating port of
The control circuit controls the high-frequency power supply unit so as to individually energize each of the induction heating coils in a heating port including a plurality of induction heating coils, and based on a change in current of the plurality of induction heating coils. When the movement of the cooking container is detected, the nearest optimum position of the cooking container moved from one or more induction heating coils that are energized is determined, and the deviation between the current position of the cooking container and the optimum position is calculated. Then, one or more of the plurality of induction heating coils to be energized are selected from the plurality of induction heating coils so as to move the cooking container to the optimum position based on the deviation, and the currents flowing through the selected induction heating coils are respectively calculated. An induction heating cooker characterized by causing the calculated current to flow through the selected induction heating coil.

Images