JP5423202B2 - Electromagnetic cooker - Google Patents

Description

  The present invention relates to an electromagnetic cooker used in general homes, offices, restaurants and the like.

  Conventionally, this type of electromagnetic cooker has one heating coil formed in a spiral shape with respect to one object to be heated, and adjusts the heating power by driving and controlling one heating coil with a high-frequency inverter. (For example, see Patent Document 1).

  In addition, a heating coil divided so that the heating area corresponds to two types of objects to be heated is provided, and heating according to the size of the object to be heated is performed according to the operation content of the operation key for selecting the object to be heated (For example, refer to Patent Document 2).

JP 2004-031247 A JP-A-5-47463

  However, in the prior art described in Patent Document 1, if the size of the heating coil and the object to be heated is different, the leakage magnetic flux increases and the heating efficiency decreases, or the heating distribution is uneven and the cooking performance decreases. There is a problem that the size of the object to be heated is limited.

  In the prior art described in Patent Document 2, a heating coil divided so as to correspond to two types of objects to be heated can be provided, and a heating area can be selected with an operation key for selecting large and small objects to be heated. When the object to be heated is heated, the other heating coil is wasted. Therefore, when this conventional technology is used in a multi-port electromagnetic cooker having a large number of induction heating sections, one can select a large and small object to be heated, while the other cannot secure a space for installing a heating coil. There is a problem that only an object to be heated can be heated.

  In addition, when a plurality of heating coils are operated simultaneously, there is a problem that interference sound is generated due to a difference in driving frequency of each of the plurality of heating coils.

  The present invention solves the above-described conventional problems, and changes the position, size, and quantity of induction heating units having two or more openings by changing the position, size, and quantity of a heating coil that can be energized. It is an object of the present invention to provide an electromagnetic cooker that can perform power control while suppressing interference noise.

In order to solve the conventional problems, the electromagnetic cooker according to the present invention has a translucent top plate for placing an object to be heated, and is arranged in substantially the same plane below the top plate . A plurality of heating coils, a heating operation unit that inputs instructions for starting and stopping heating of the heating coils, and a heating power setting, an inverter unit that controls the plurality of heating coils, and an instruction input to the heating operation unit In order to adjust at least one of the position, size, and quantity of the control unit that controls the inverter unit and the induction heating unit, a heating coil that can be energized among a plurality of heating coils cannot be energized. An information storage unit that selects a heating coil, stores a heatable region on the top plate, heating coil pattern information that forms a non-heatable region, and a plurality of the heating coils stored in the information storage unit Selecting means for selecting one of said heating coil pattern information from the turn information, the top of the heatable region is formed based on the heating coil pattern information selected by said selecting means is provided below the top plate Light display means for displaying on the energizable heating coil of the plate, and the control section can be energized with the heating coil pattern information selected by the selection means based on an instruction input to the heating operation section. An electromagnetic cooker that controls the driving frequency of each heating coil to be a predetermined frequency difference or more ,
The drive frequency of each of at least two or more heating coils that can be energized constituting one induction heating unit in the heatable region is replaced every time a predetermined time elapses .

  This makes it possible not only to adjust the positions of two or more induction heating units, but also to perform power control while suppressing interference noise.

  The electromagnetic cooker of the present invention can select the combination pattern of the heating coil that can be energized and the heating coil that cannot be energized by the selection means, and change any of the position, size, and quantity of the induction heating unit. This makes it possible to perform power control while suppressing interference sound.

External view of the electromagnetic cooker 1 in the first embodiment of the present invention Circuit diagram of electromagnetic cooker 1 in the first embodiment of the present invention The figure which shows the memory | storage data of the information storage part in the 1st Embodiment of this invention The block diagram of the optical display means in the 1st Embodiment of this invention The circuit diagram of the inverter part of the electromagnetic cooker 1 in the 1st Embodiment of this invention The block diagram of the heating operation part in the 1st Embodiment of this invention Relationship diagram between the plurality of heating coils 7 in the first embodiment of the present invention, the heatable region formed on the top plate 10, and the non-heatable region Conversion diagram of pattern of heatable region in the first embodiment of the present invention Current waveform diagram of nine heating coils located below the heatable region A27 in the first embodiment of the present invention Current waveform diagram of four heating coils located below heatable region C29 in the first embodiment of the present invention The figure which shows other embodiment of this invention The figure which shows other embodiment of this invention The figure which shows the control characteristic of the drive frequency and heating power (input electric power) of the heating coil

According to a first aspect of the present invention, there is provided a translucent top plate for placing an object to be heated, a plurality of heating coils disposed substantially in the same plane below the top plate, and heating of the heating coil A heating operation unit for inputting instructions for starting and stopping the heating power setting, an inverter unit for controlling the plurality of heating coils, and a control unit for controlling the inverter unit based on the instructions input to the heating operation unit; In order to adjust at least one of the position, size, and quantity of the induction heating unit, a heating coil that can be energized and a heating coil that cannot be energized are selected from among the plurality of heating coils, An information storage unit that stores heating coil pattern information that forms a heatable region, a non-heatable region, and one heating coil from a plurality of the heating coil pattern information stored in the information storage unit Selecting means for selecting the turn information, said top plate of said energizable heating coil of the heating region said top plate is formed based on the heating coil pattern information selected by the selecting means provided below Light control means for displaying on the control unit , and the control unit is configured to drive each of the heating coils that can be energized by the heating coil pattern information selected by the selection unit based on an instruction input to the heating operation unit. An electromagnetic cooker that controls the drive so that the difference in frequency exceeds a predetermined frequency ,
By replacing the drive frequency of each of at least two or more heating coils that constitute energization that constitute one induction heating unit in the heatable region every time a predetermined time elapses , the position of the induction heating unit is changed. In addition to being able to change at least one of size and quantity, it is possible to perform power control while suppressing interference sound. In addition, the user can visually recognize the position, size, and quantity of the induction heating unit, and the user can select the necessary position, size, and quantity according to the cooking menu. In addition, the temperature distribution of the object to be heated can be made uniform.

According to a second aspect of the present invention, in the electromagnetic cooker of the first aspect of the invention, at least one or more semiconductor switches for connecting / disconnecting the plurality of heating coils and the commercial power source are provided in the inverter unit for controlling the plurality of heating coils. By providing the inverter circuit provided and changing the conduction time of the semiconductor switch, it becomes possible to control the power supply time to the heating coil that is set to be energized, and the power control while suppressing the interference sound it can.

In particular, the third invention operates one selection means by switching the heating coil pattern information to be selected each time one selection means is operated in the electromagnetic cooker according to the first or second invention. Thus, the user can select the position, size, and quantity of the induction heating unit necessary for the cooking menu, and the operation can be simplified.

In the fourth aspect of the invention, in particular, in the electromagnetic cooker according to any one of the first to third aspects, the selection means can be operated only when the inverter unit is stopped. It is possible to prevent the heatable area from changing by operating the selection means, and by retracting the object to be heated not to be heated to the non-heated area, the pan is heated against the intention of the user, It becomes possible to prevent unsafe situations such as cooking failure and ignition due to empty baking, and it is possible to improve usability and safety.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is an external view of an electromagnetic cooker 1 according to the first embodiment of the present invention. Moreover, FIG. 2 shows the circuit diagram of the power converter circuit of the electromagnetic cooker 1 in the 1st Embodiment of this invention. FIG. 3 shows data stored in the information storage unit in the first embodiment of the present invention. FIG. 4 shows a block diagram of the light display means in the first embodiment of the present invention. FIG. 5 shows a circuit diagram of the inverter unit of the electromagnetic cooking device 1 according to the first embodiment of the present invention. Moreover, FIG. 6 shows the block diagram of the heating operation part in the 1st Embodiment of this invention.

The electromagnetic cooker 1 shown in FIGS. 1 and 2 has a predetermined frequency by a switching element that is turned on / off at a predetermined timing via a filter circuit unit 3 including a rectifier circuit, a power factor correction circuit, and the like from a 200 V commercial power supply 2. An inverter circuit 4 that generates a high-frequency power, an inverter unit 5 composed of a plurality of inverter circuits 4, a control unit 6 that drives and controls the inverter unit 5, and a plurality of heating coils 7 that generate a high-frequency magnetic flux by the high-frequency power, A heating coil portion 8 composed of a plurality of heating coils 7 arranged on substantially the same plane, output power detection means 9 for detecting output power supplied to the heating coil portion, and arranged above the plurality of heating coils 7. The hard glass top plate 10 to be heated, the heated object 11 disposed above the top plate 10, and the user adjusts the output power or temperature. Heating operation unit 12, display means 13 for displaying the status of output setting, temperature, automatic cooking menu, etc., and at least the position, size and quantity of two or more induction heating units or one induction heating unit An information storage unit 14 that stores a plurality of heating coil pattern information that is information for selecting a heating coil 7 that can be energized and a heating coil 7 that cannot be energized among the plurality of heating coils 7 in order to adjust any of them. And a selection means 15 for selecting one heating coil pattern information from a plurality of heating coil pattern information stored in the information storage unit 14 at a position different from the heating operation unit 12.

  As shown in FIG. 3, the information storage unit 14 stores heating coil pattern information. In the microcomputer of the information storage unit 14, a heating coil that can be energized and a heating coil that cannot be energized are selected, and a heating area and a plurality of heating coil pattern information forming a non-heating area are formed on the top plate. In the present embodiment, four patterns shown in FIGS. 3A to 3D are stored. Further, by increasing other combinations, it becomes possible to supply a heatable area according to various cooking menus, and it is needless to say that the usability can be improved. The microcomputer of the information storage unit 14 is a flash type that can be rewritten any number of times, so that heating coil pattern information can be added / deleted, and it can be adapted to the usage situation of the user.

  Furthermore, as shown in FIG. 4, the electromagnetic cooker 1 includes a light guide unit 16 a disposed below the top plate 10 and a light emitting unit 16 b that generates light that passes through the top plate 10, and the selection unit 15. The light display means 16c which displays the outer peripheral part of the heatable area | region formed based on the heating coil pattern information selected by (1) on the top plate 10 is shown. The control unit 6 also controls the light emitting unit 16b. And based on the heating coil pattern information memorize | stored in the information storage part 14 selected by the selection means 15, the control part 6 controls the light emission part 16b, and displays a heatable area | region on the top plate 10. FIG.

  Moreover, the electromagnetic cooker 1 has the main power switch 17 which connects / disconnects the 200V commercial power supply 2 and the filter circuit part 3, as shown in FIG.

  Here, the induction heating unit means a group of heating coils 7 that constitute one heatable region and can be energized.

  In the inverter circuit 4 shown in FIG. 5, the collector of the first switching element 17 is connected to the high potential side of the output of the filter circuit unit 3, and the collector of the second switching element 18 is connected to the emitter of the first switching element 17. Connected, the emitter of the second switching element 18 is connected to the low potential side of the output of the filter circuit section 3, the snubber capacitor 19 is connected between the collector and emitter of the second switching element 18, and resonance with the heating coil 7. A series circuit of the capacitor 21 and the output power detection unit 9 is connected to both ends of the snubber capacitor 19 to receive the heating start, heating power adjustment, heating stop signal from the control unit 6 and the detection result of the output power detection unit 9. The output of the ratio setting unit 20 is connected to the gates of the first switching element 17 and the second switching element 18.

  As for the output power to the heating coil 7, the conduction ratio setting unit 20 receives the heating start, heating power adjustment, and heating stop signals sent from the control unit 6 based on the operation content of the heating operation unit 12, and the output power detection unit The heating operation is controlled by setting the conduction ratio and the switching frequency of the first switching element 17 and the second switching element 18 while comparing with the detection result 9.

  Usually, as shown in FIG. 2, one filter circuit unit 3 is shared by 40 heating coils and an inverter circuit 4 configured in a one-to-one manner, thereby reducing the number of parts and reducing the size and cost of electromagnetic cooking. The vessel is realized. In this embodiment, 40 heating coils and 40 inverter circuits are provided. However, if N inverter circuits are provided, N heating coils can be connected, and the number of heating coils is reduced. If the number is increased, it becomes possible to set the position, size, and quantity of the induction heating unit that can cope with a finer cooking scene, and the cooking performance can be improved.

  Further, by adopting a configuration in which two or more heating coils are connected in parallel to one inverter circuit, the number of inverter circuits can be made smaller than the number of heating coils, and an inexpensive and small electromagnetic cooker is supplied. be able to. However, since a plurality of heating coils cannot be controlled independently, in the present embodiment, as shown in FIG. 2, a plurality of heating coils 7 and a one-to-one inverter circuit are connected. Each coil can be independently controlled, and the cooking temperature can be improved by making the temperature distribution at the bottom of the pan uniform. Therefore, the electromagnetic cooking device 1 according to the present embodiment includes the first heating coil 7 (1) to the 40th heating coil 7 (40) and the first inverter circuit 4 (1) to the 40th inverter circuit, respectively. 4 (40) can be individually driven and controlled. In addition, although the inverter circuit 4 in this Embodiment uses the single-ended push-pull type inverter, it cannot be overemphasized that a bridge type inverter can be applied.

  In addition, the heating operation unit 12 has a number of operation units capable of operating at least two induction heating units, and the heating operation unit 12 of the present embodiment corresponds to each heatable region as shown in FIG. In order to be able to do, it is comprised by three operation parts, the 1st heating operation part 12a, the 2nd heating operation part 12b, and the 3rd heating operation part 12c.

  Each operation unit includes a “heating on / off” key 22, an “output up” key 23, an “output down” key 24, a “cooking menu” key 25, and a “timer” key 26.

  Further, FIG. 7 shows a relationship diagram between the plurality of heating coils 7, the heatable region formed on the top plate 10, and the non-heatable region.

  As shown in FIG. 7, the plurality of heating coils 7 have a spiral circular shape with a diameter of 70 mm. However, other shapes such as a rectangle, an ellipse, a polygon, or a combination thereof may be used. Further, the plurality of heating coils 7 are 40 in a total of 8 rows in the horizontal direction and 5 rows in the vertical direction. Further, although the plurality of heating coils 7 are arranged vertically and horizontally, there is no problem even if they are not aligned. Therefore, it is possible to make the temperature distribution uniform by arranging the heating coils in a circular shape, a rectangular shape, an elliptical shape, a polygonal shape, or a combination thereof, and arranging a plurality of heating coils in substantially the same plane without gaps. In addition, it is possible to supply the shape of the induction heating unit suitable for an irregularly shaped pot bottom such as an elliptical diameter.

  Moreover, the heating operation unit 12 is a touch key that detects the capacitance, so that the heating operation unit 12 is not deteriorated as compared with the mechanical switch, and the durability of the electromagnetic cooking device can be improved. However, there is no problem even if it is replaced with a push switch key or a voice key.

  Further, a system including a step-up / step-down / step-up / step-down circuit after the filter circuit unit 3 of the power conversion circuit may be used, and the heating power is adjusted by stepping up / stepping down the inverter power supply while fixing the operating frequency of the inverter circuit. It becomes possible.

Moreover, although the light display part 16c in this Embodiment uses LED for the light emission part 16b,
Different light emitting devices such as lasers and fluorescent tubes may be used.

  The operation and action of the electromagnetic cooker 1 configured as described above will be described below.

  When the user turns on the main power switch 17 of the electromagnetic cooker 1 to connect the 200V commercial power supply 2 and the filter circuit unit 3, the power conversion circuit shown in FIG. 2 is energized. At this time, the control unit 6 reads the heating coil pattern information (a) set to the initial value of the heating coil pattern information from the information storage unit 14, and the control unit 6 controls the light emitting unit 16 b and controls the top plate 10. Then, the heatable region shown in FIG. In addition, by setting the heating coil pattern information used last time to the initial value of the heating coil pattern information in the information storage unit 14, it becomes possible to set the pattern of the heatable region with high use frequency as the initial pattern, It is possible to improve the usability by omitting the user's trouble of selecting each time.

  In the electromagnetic cooking device 1 according to the present embodiment, when the selection unit 15 arranged in the vicinity of the heating operation unit 12 on the top plate 10 is operated by the user, the control unit 6 starts from the information storage unit 14 in a predetermined order. Read out the heating coil pattern information, select the heating coil 7 that can be energized and the heating coil 7 that cannot be energized among the plurality of heating coils 7, adjust the position, size and quantity of the induction heating part, On the plate 10, a heatable region and a non-heatable region according to the user's desire are formed.

  Then, the user can visually recognize the heatable area on the top plate by the light display means 16c. In this Embodiment, it sets so that heating coil pattern information may be read from the information storage part 14 in order of (a), (b), (c), (d), and the control part 6 is from the information storage part 14. The heating coil pattern information (a), (b), (c), and (d) are read in the order, and the control unit 6 controls the light emitting unit 16b, and on the top plate 10, FIGS. ), (C), and (d) are displayed in order of heatable areas.

  The user selects the heating coil pattern information by the selection means 15 and selects the optimum pattern for the cooking menu while visually recognizing the heatable area displayed on the top plate 10.

  That is, by selecting the heating coil pattern information by the selection unit 15, the three heating units shown in FIG. 8B can be heated from the three induction heating units forming the three heatable regions shown in FIG. The position and size of the induction heating unit are adjusted to the three induction heating units forming the region. Further, the position of the induction heating unit from the three induction heating units forming the three heatable regions shown in FIG. 8B to the one induction heating unit forming the one heatable region shown in FIG. 8C. Adjust the size and quantity. Further, the position of the induction heating unit is changed from one induction heating unit forming one heatable region shown in FIG. 8C to two induction heating units forming two heatable regions shown in FIG. 8D. Adjust the size and quantity.

  When the user selects an appropriate heatable area in the cooking menu by selecting the selection means 15, the user places the object to be heated 11 such as a pan or a frying pan on the induction heating unit to be used, and performs the corresponding heating. The “heating on / off” key 22 of the operation unit 12 is operated to start heating.

  The induction heating unit that forms the heatable region A27 shown in FIG. 8A is operated by the first heating operation unit 12a, and the induction heating that forms the heatable region B28 shown in FIG. It is assumed that the induction heating unit forming the heatable region C29 shown in FIG. 8A is operated by the third heating operation unit 12c.

When using the induction heating unit that forms the heatable region A27, heating is started with the “heating on / off” key 22 of the first heating operation unit 12a, and the “output up” key 23, “ The "output down" key 24, the "cooking menu" key 25, and the "timer" key 26 are operated for cooking. Similarly, when using the induction heating unit that forms the heatable region B28, the second heating operation unit 12b is used, and when using the induction heating unit that forms the heatable region C29, the third heating operation unit 12c is used. Use to operate.

  When the number of induction heating parts is smaller than the number of operation parts as in the induction heating parts corresponding to FIGS. 8C and 8D, it may be assigned to one of the three heating operation parts 12a to 12c.

  Based on the selected heating coil pattern information, the control unit 6 sets at least one or more heating coils as one induction heating unit, and starts heating, adjusts thermal power, and stops heating almost simultaneously.

  Based on the selected heating coil pattern information, the control unit 6 sets at least one or more heating coils as one induction heating unit, and starts heating, adjusts thermal power, and stops heating almost simultaneously. As shown in FIG. 7, nine heating coils 7 (1) to (9) are provided below the induction heating unit A27 in FIG. 8A, and the induction heating unit B28 is provided with nine heating coils 7 ( 10) to (18), the induction heating section C29 has four heating coils 7 (19) to (22) located below, and starts heating, adjusts the heating power, and stops heating substantially simultaneously. . For example, when an iron pan is heated by the induction heating unit A27 in FIG. 7 (a) with a heating power of 500 W, the current waveform flowing through the lower heating coils 7 (1) to (9) is as shown in FIG. When the iron pan is heated by the induction heating unit C29 in FIG. 8A at a heating power of 500 W, the current waveforms flowing through the lower heating coils 7 (19) to (22) are as shown in FIG. At the same time, heating is stopped.

  Further, as shown in FIG. 9 or FIG. 10, the control unit 6 performs drive control so that the drive frequency of each heating coil determined to be energized is equal to or greater than a predetermined frequency difference. The electromagnetic cooker 1 according to the present embodiment causes interference generated due to a frequency difference even when two or more heating coils operate at different driving frequencies by setting the predetermined frequency difference to be an audible frequency or higher. Sound can be suppressed. That is, the drive frequency difference of the heating coil in FIG. 9 is set to be higher than the audible frequency (20 kHz or higher).

  Further, when the conduction ratio setting unit 20 (1) receives the heating power up signal and operates at a heating power of 3000 W, the waveforms of the heating coils 7 (1) to (9) shown in FIG. 9 become the waveforms shown in FIG. 9, the heating coil 7 (1) operates at 25 kHz, and when the heating power setting is set to 3000 W, the heating coil 7 (1) operates at 21 kHz, and the other heating coils 7 (2) to 7 (9 ) Also adjusts the thermal power by setting the frequency lower. Also, when lowering the thermal power, the frequency is set higher. FIG. 13 shows the control characteristics of the driving frequency and heating power (input power) of the heating coil.

  Moreover, as shown in FIG. 9, since the output power of each heating coil will differ if the drive frequency of the several heating coil used as one induction heating part differs, there exists a subject that a nonuniformity arises in heating distribution. Therefore, the electromagnetic cooking device 1 according to the first embodiment can make the temperature distribution uniform by sequentially changing the set frequencies of each of the plurality of heating coils that form one induction heating unit for each predetermined period. Control as you can. As shown in FIG. 12, in this embodiment, the set frequencies of the plurality of heating coils are sequentially changed every 5 seconds. For example, assuming that FIG. 9 is a waveform of the heating coil at a certain time t = 0 seconds, the set frequencies of the heating coils 7 (1) to 7 (9) are f (1), f (2),... F (9). Then, at t = 5 seconds after 5 seconds, the set frequencies of the heating coils 7 (1) to 7 (9) are f (9), f (1), f (2),... F (8). The temperature distribution in the pan can be made uniform by sequentially changing.

  Further, in FIG. 8A, the heating coils located below the non-heatable areas other than the heatable areas A27, B28, and C29 are not energized. ). The same applies to FIGS. 8B to 8C. Furthermore, by making it possible to visually recognize the heatable area with the light display means 16c, the place where the pan, lid, knife, etc., which is not to be heated is clarified, and the pan contrary to the intention of the user can be obtained. It can be heated to prevent ignition due to empty baking, improving usability and safety.

  Further, among at least one or more heatable regions displayed on the top plate 10 by the light display means 16c, one or more heatable regions are in a heating operation, that is, the inverter unit 5 is driven. In some cases, the operation of the selection means 15 is invalidated so that the selection means 15 is accidentally touched and the position, size, and quantity of the induction heating unit do not change against the user's intention. That is, by making it possible to operate the selection means 15 only when the inverter unit 5 is stopped, it is possible to prevent unsuccessful cooking due to cooking failure or unintentional cooking of the pan.

  As described above, the electromagnetic cooker 1 according to the present embodiment adjusts at least one of the position, size, and quantity of the induction heating unit, so that the position, size, By adjusting at least one of the quantities, the heated object is heated at an easy-to-use position, heated according to the size of the heated object to be used, or heated according to the number of heated objects to be used. In addition to adjusting the position, size, and quantity of the non-heatable area, the object to be heated that is not heated is retreated to the non-heatable area adjusted by the user. Thus, it is possible to prevent the pan from being heated against the intention of the user, and to prevent unsafe conditions such as cooking failure or ignition due to empty baking, and the usability and safety can be improved.

  Furthermore, power control can be performed while suppressing interference noise.

  Further, in the present embodiment, particularly when one induction heating unit is formed by a plurality of heating coils, the heating coils constituting the one induction heating unit are heated or stopped substantially simultaneously. By controlling the inverter unit, the control unit can operate a plurality of heating coils as one heating coil, so that the user does not need to operate each of the plurality of heating coils. Reduced and easy-to-use cooker can be supplied.

  Further, in the present embodiment, by changing the conduction time of the first switching element 17 of the inverter unit 5, it is possible to energize by changing the time for connecting / disconnecting the heating coil 7 and the commercial power source 2. The power supply time to the set heating coil 7 can be controlled, and the power can be controlled while suppressing the interference sound.

  Moreover, in this Embodiment, whenever the selection means 15 is operated, the position of the induction heating part which a user requires for a cooking menu by operating the selection means 15 by switching the heating coil pattern information to select, The size and quantity can be selected, and the operation can be simplified.

  In the present embodiment, since the selection means 15 can be operated only when the inverter unit 5 is stopped, the position of the induction heating unit can be detected even if the user accidentally operates the selection means 15 during heating. By preventing the size and quantity from changing, it is possible to prevent the pot that is against the user's intention from being heated, cooking failure, and unsafe firing such as empty baking, etc. Can be improved.

  Further, in the present embodiment, the light display means 16 is provided and at least one induction heating unit is displayed on the top plate 10, thereby allowing the user to visually recognize the position, size, and quantity of the induction heating unit. The user can select the necessary position, size and quantity according to the cooking menu.

  In the present embodiment, the drive frequency of each of at least two or more heating coils that can be energized constituting one induction heating unit in the heatable region is replaced every time a predetermined time elapses. As a result, the temperature distribution of the object to be heated can be made uniform. By exchanging, the temperature distribution of the object to be heated can be made uniform.

  As described above, the electromagnetic cooker 1 according to the present invention controls the driving frequency of the heating coils 8 that can be energized by the heating coil pattern information so that the driving frequency is equal to or greater than a predetermined frequency difference. It is possible to adjust the position, size, and quantity of two or more induction heating units without generating any problems, and it can be applied not only to general homes and offices but also to professionals such as restaurants.

DESCRIPTION OF SYMBOLS 1 Electromagnetic cooker 5 Inverter part 6 Control part 7 Heating coil 9 Output power detection means 12 Heating operation part 14 Information storage part 15 Selection means 16C Light display means

Claims (4)

A top plate for placing an object to be heated having translucency, a plurality of heating coils arranged substantially in the same plane under the top plate, and heating start, stop and heating power of the heating coil Positions of the heating operation unit for inputting setting instructions, the inverter unit for controlling the plurality of heating coils, the control unit for controlling the inverter unit based on the instructions input to the heating operation unit, and the induction heating unit In order to adjust at least one of the size and quantity, a heating coil that can be energized and a heating coil that cannot be energized are selected from among a plurality of heating coils, a heatable area on the top plate, and heating An information storage unit that stores heating coil pattern information that forms an impossible area, and one heating coil pattern information from the plurality of heating coil pattern information stored in the information storage unit. A selection means for selecting, and the heatable area formed on the basis of the heating coil pattern information provided below the top plate and selected by the selection means is displayed on the energized heating coil of the top plate And a light display means for controlling the heating frequency of each heating coil to be energized based on the heating coil pattern information selected by the selection means based on an instruction input to the heating operation section. An electromagnetic cooker characterized in that drive control is performed so as to be equal to or greater than the frequency difference ,
An electromagnetic cooker characterized in that , among the heatable regions, the drive frequency of each of at least two or more heating coils constituting one induction heating unit is switched every time a predetermined time elapses . . An inverter circuit including at least one semiconductor switch for connecting / disconnecting the plurality of heating coils and the commercial power source is provided in the inverter unit that controls the plurality of heating coils, and the conduction time of the semiconductor switch is changed. The electromagnetic cooker according to claim 1, wherein 3. The electromagnetic cooker according to claim 1, wherein the heating coil pattern information to be selected is switched every time one selection unit is operated. 4. The electromagnetic cooker according to any one of claims 1 to 3 , wherein the selection means can be operated only when the inverter unit is stopped.