JP6685342B2 - Induction heating cooker - Google Patents

Description

  The present invention relates to an induction heating cooker using an induction heating means for inducing an eddy current in an object to be heated for induction heating.

  Conventionally, as a substitute for a coil for induction heating of a so-called IH cooking heater, "a heating part arranged facing the object to be heated, and a conductor forming an electrically closed circuit having a power supply part together with the heating part, An induction device including a magnetic body arranged to surround the power feeding portion, a coil formed by winding a conductive wire so as to intersect the magnetic body a plurality of times, and a high-frequency power supply that supplies a high-frequency current to the coil. A device to which a heating device is applied has been proposed (for example, see Patent Document 1).

JP, 2015-35424, A (claim 1, pp. 14-15).

  The heating cooker described in Patent Document 1 not only heats an object to be heated by the induction heating principle by a high frequency current, but also Joule heat generated by the electric resistance of the conductor itself due to the induction current flowing through the conductor. It is used to heat objects to be heated. It is expected that the temperature of this conductor will be as high as 500 ° C., and the temperature of the top plate (top plate) interposed between the object to be heated and the conductor will also be high, and the induction heating cooker will stop heating. The top plate may continue to be hot for a while after the operation.

  Here, the top plate of the induction heating cooker in a state where heating is stopped is also used as a workbench. However, when the top plate is in a high temperature state, there is a problem that it is difficult to use the top plate as a workbench. Further, the induction heating cooker is provided with a temperature sensor for detecting the temperature of the object to be heated, and the detection accuracy of this temperature sensor is also affected by the temperature of the top plate itself. Therefore, if the heating of the object to be heated is started after the heating is stopped and the top plate is in a high temperature state, the temperature detection accuracy of the object to be heated will be reduced. Further, in order to ensure the temperature detection accuracy, it is necessary to wait for the start of heating until the temperature of the top plate returns to about room temperature, and there is a problem that usability is reduced.

  The present invention has been made to solve the above problems, and provides an induction heating cooker capable of quickly lowering the temperature of the top plate while the induction heating is stopped.

An induction heating cooker according to the present invention is arranged such that a top plate on which an object to be heated is placed, a first power supply that outputs a high frequency current, a second power supply, and a back surface of the top plate are facing each other. An induction heating plate composed of a flat plate-shaped conductive material, a transformer having the first power source connected to the primary side and the induction heating plate connected to the secondary side, and the induction heating plate being in contact with the transformer. the is driven by power supplied from the second power supply and a cooling unit for cooling the top plate, based on the presence or absence of the object to be heated on said top plate, the high frequency output from the first power supply The current and the operation of the cooling unit are controlled.

  According to the present invention, the cooling unit cools the top plate while the induction heating is stopped, so that the top plate can be quickly used as a workbench or a storage table after the heating is stopped, and the usability of the heating cooker is improved. be able to.

FIG. 3 is a perspective view of the induction heating cooker according to the first embodiment. It is a figure which shows the structure of the principal part of the induction heating cooking appliance which concerns on Embodiment 1. It is a schematic plan view of the induction heating plate of the induction heating cooker according to the first embodiment. It is a figure which shows the structure of the principal part of the induction heating cooking appliance which concerns on Embodiment 2. It is a schematic plan view of the induction heating plate of the induction heating cooking appliance which concerns on Embodiment 2. 9 is a flowchart illustrating a cooling operation of a top plate of the induction heating cooker according to the second embodiment. 9 is a flowchart illustrating a cooling operation of a top plate of the induction heating cooker according to the third embodiment. It is a flowchart explaining the cooling operation of the top plate of the induction heating cooker according to the fourth embodiment. It is a figure which shows the structure of the principal part of the induction heating cooking appliance which concerns on Embodiment 5. It is a schematic plan view of the induction heating plate of the induction heating cooking appliance which concerns on Embodiment 6. It is a schematic plan view which shows the other example of the induction heating plate of the induction heating cooking appliance which concerns on Embodiment 6. It is a schematic diagram explaining the principal part cross section of the induction heating cooking appliance which concerns on Embodiment 6.

  Hereinafter, an embodiment of an induction heating cooker according to the present invention will be described with reference to the drawings. The present invention is not limited to the embodiments shown in the drawings. Further, in the following description, in order to facilitate understanding, terms indicating directions (for example, “upper”, “lower”, “right”, “left”, “front”, “rear”, etc.) are appropriately used. This is for illustration only and these terms do not limit the invention. Further, in each of the drawings, the same reference numerals are the same or equivalent to each other, and this is common to all the texts in the specification. In each drawing, the relative dimensional relationship or shape of each component may differ from the actual one.

Embodiment 1.
FIG. 1 is a perspective view of the induction heating cooker according to the first embodiment. The induction heating cooker 100 has a substantially box-shaped casing 1, and a top plate 2 on which an object to be heated such as a pot or a frying pan is placed is provided on the casing 1. The top plate 2 is made of, for example, a non-metal material such as ceramics, heat-resistant glass, and crystallized glass. The induction heating cooker 100 is provided with three heating ports 3, and an object to be heated is placed on each heating port 3 and heated.

  An operation unit 4 that receives an operation input from a user is provided on the front side of the upper surface of the induction heating cooker 100 and on the front wall of the housing 1. The operation unit 4 includes, for example, a push button, a dial switch, a capacitance type touch switch, and the like. A display unit 5 is provided on the front side of the top plate 2. The display unit 5 has a device for visually notifying information such as a liquid crystal display and an LED, and is used for the user to input the operating state such as the heating power of the induction heating cooker 100, the time of the timer, and the like by the user. Notification of options, warnings to users, and alerts.

  Further, the top plate 2 is provided with a high temperature caution display portion 6. The high-temperature caution display unit 6 is a display unit that provides a visual notification to call the user's attention when the temperature of the top plate 2 is high. Here, the high temperature refers to a temperature at which the user should be warned, and can be determined in consideration of the usage conditions of the induction heating cooker 100 and the like. The high-temperature caution display unit 6 may be one that displays a warning message using, for example, a liquid crystal display, or one that illuminates a warning message or a drawing provided on the top plate 2 with a lamp such as an LED. May be

  The number, arrangement, and specific configuration of the heating port 3, the operation unit 4, the display unit 5, and the high temperature caution display unit 6 do not limit the present invention, and any other device can be used as long as the same function is exhibited. Specific configurations other than those exemplified in the embodiment can be adopted.

  FIG. 2 is a diagram showing a configuration of a main part of the induction heating cooker according to the first embodiment. FIG. 3 is a schematic plan view of the induction heating plate of the induction heating cooker according to the first embodiment. 2 illustrates the object to be heated 200 placed on the surface of the top plate 2 for the sake of explanation, the object to be heated 200 does not constitute the present invention. The induction heating cooker 100 includes an induction heating plate 7 provided under the top plate 2, a transformer 8, a first power source 11 for supplying power to the transformer 8, a cooling unit 12, and a cooling unit 12. It has the 2nd power supply 13 which supplies a power supply, the 1st power supply 11, the 2nd power supply 13, the control part 14 which controls the display part 5 and the high temperature caution display part 6, and the magnetic material 15. The operation input from the operation unit 4 is input to the control unit 14.

  The induction heating plate 7 is a plate-shaped member made of a conductive material such as metal having a low electric resistance such as aluminum or copper. The induction heating plate 7 is arranged below the top plate 2 so that its flat plate surface faces the back surface of the top plate 2. The planar shape of the induction heating plate 7 is an annular shape that forms an electrically closed circuit as shown in FIG. In the induction heating plate 7 of the present embodiment, a plate-shaped member is processed into an annular shape by cutting, pressing, or the like, and then the induction heating plate 7 is bent at a substantially right angle in the middle of the length direction. As shown in FIG. 2, it is formed in an L shape in a side view. The vertically extending portion of the induction heating plate 7 that is bent in an L shape is referred to as a vertical portion 71. The induction heating plate 7 is provided for each heating port 3. The specific shape of the induction heating plate 7 is not limited to that shown in the figure.

  The transformer 8 includes a vertical portion 71, which is a part of the induction heating plate 7, a coil 10 formed by winding a coated copper wire a plurality of times, and a high-frequency magnetic flux generated when a high-frequency current flows through the coil 10. 71 and a magnetic body 9 arranged so as to form a magnetic circuit interlinking with 71.

  The coil 10 can be formed, for example, by winding a so-called litz wire in which a coated copper wire obtained by coating a copper wire having a diameter of about 0.3 mm with a resin into 36 strands is wound a plurality of times in a flat plate shape. The diameter and the number of twists of the copper wire (element wire) of the litz wire used for the coil 10 are not limited to this, and for example, a coated copper wire may be used instead of the litz wire, or a copper wire may be used instead. Aluminum wire may be used. Further, the shape of the coil 10 is not limited to the flat plate shape, and may be any shape as long as the high frequency magnetic flux generated by the coil 10 links the vertical portion 71 of the induction heating plate 7.

  The magnetic material 9 is, for example, a ferrite core, an iron core formed by laminating silicon steel plates having a thickness of about 0.1 mm, an amorphous core formed of an amorphous thin film, and a powdered material containing a magnetic material powder such as iron as a main component. It is also possible to use a dust core or the like formed by resin fixation or the like. An insulating layer such as glass wool or ceramic wool (not shown) is arranged between the magnetic body 9 and the coil 10 and the vertical portion 71 to electrically insulate them.

  The end of the conductive wire of the coil 10 is connected to the first power supply 11. The first power supply 11 supplies the coil 10 with high frequency power of, for example, about 20 kHz to 40 kHz and about 30 Arms. The first power supply 11 may be, for example, a full bridge circuit, a half bridge circuit, or a single-stone resonance type circuit using a semiconductor switching element such as an IGBT or MOSFET.

  When a high frequency current (coil current) is supplied from the first power supply 11 to the coil 10, a high frequency magnetic flux φ1 is generated around the coil 10. The high frequency magnetic flux φ1 mainly passes through the magnetic body 9 having a small magnetic resistance. Since the magnetic circuit including the magnetic body 9 is arranged so as to interlink with the vertical portion 71 of the induction heating plate 7, the high frequency magnetic flux φ1 interlinks with the vertical portion 71 of the induction heating plate 7. As a result, an induction current flows through the vertical portion 71 of the induction heating plate 7 by electromagnetic induction. If the coil 10 is a primary winding with N turns, the induction heating plate 7 becomes a secondary winding with 1 turn and is transformed into N: 1 by the transformer 8. Therefore, a large current larger than the coil current flows through the vertical portion 71 of the induction heating plate 7 at the same frequency as the coil current. Specifically, when the coil 10 has 20 turns, the transformer 8 converts the current 1:20. If the current of the first power supply 11 is 30 Arms, the induction heating plate 7 on the secondary side has A current of 600 Arms is generated.

  When a high frequency induction current flows through the induction heating plate 7, a high frequency magnetic flux φ2 is generated around the induction heating plate 7. The high-frequency magnetic flux φ2 passes through the object to be heated 200 arranged in the vicinity of the induction heating plate 7, so that an eddy current is generated in the object to be heated 200, and Joule heat of the eddy current causes the object to be heated 200 to generate heat.

  The cooling unit 12 is thermally connected to the top plate 2 via the induction heating plate 7 and cools the top plate 2. That is, the cooling unit 12 is thermally connected to the back surface of the induction heating plate 7, and when the cooling unit 12 cools the induction heating plate 7, the top plate 2 is cooled via the induction heating plate 7. . The cooling unit 12 receives power supply from the second power supply 13 and performs a cooling operation. As a specific configuration of the cooling unit 12, for example, a Peltier element can be used. The Peltier element is a semiconductor element capable of controlling heat generation and heat absorption by an electric current, and has a structure in which two metal plates forming a heat absorbing surface and a metal plate forming a heat radiating surface are laminated. When a Peltier element is used as the cooling unit 12, the heat absorption surface is arranged so as to contact the back surface of the induction heating plate 7.

  The magnetic material 15 is, for example, a ferrite core, and is arranged on the back surface of the induction heating plate 7. Although the magnetic material 15 is not an indispensable structure, it is possible to efficiently generate an eddy current in the object to be heated 200 and improve the heating efficiency by providing it on the back surface of the induction heating plate 7.

  The control unit 14 is configured by a dedicated hardware or a CPU (also referred to as a central processing unit, a central processing unit, a processing device, a computing device, a microprocessor, a microcomputer, or a processor) that executes a program stored in a memory. .

  In such a configuration, when a heating start instruction is input to the operation unit 4, the control unit 14 sends a drive signal to the first power supply 11. When the first power supply 11 supplies a high frequency current to the coil 10, the high frequency induction current transformed by the transformer 8 flows through the induction heating plate 7, and the object 200 to be heated is heated by the high frequency magnetic flux generated around the induction heating plate 7. Be heated. During such an induction heating operation, the temperature of the top plate 2 also rises due to heat transfer from the induction heating plate 7. During the induction heating operation, the control unit 14 does not operate the second power supply 13, and the cooling unit 12 does not exhibit the cooling function.

  When a heating stop instruction is input to the operation unit 4 or when the heating stop condition is satisfied by a timer function or the like, the control unit 14 sends a drive stop signal to the first power supply 11, and the first power supply 11 supplies power. To stop. When the induction heating operation is stopped, the control unit 14 sends a drive signal to the second power supply 13, and the second power supply 13 supplies power to the cooling unit 12. The cooling unit 12 that has been supplied with power cools the induction heating plate 7, and the top plate 2 is also cooled by heat transfer from the induction heating plate 7.

  When a set time (for example, 10 minutes) elapses after the cooling operation of the cooling unit 12 is started, the control unit 14 controls the second power supply 13 to stop the power supply to the cooling unit 12, and the cooling unit 12 operates. Stop the cooling operation.

  Further, during the induction heating operation, the control unit 14 can execute a load detection process that detects whether or not the induction-heated object 200 is placed on the top plate 2. Here, the load detection uses, for example, that the current flowing through the induction heating plate 7 when a high-frequency current is supplied to the induction heating plate 7 depends on the presence or absence, the material, and the size of the object to be heated 200. It can be carried out. In addition, the fact that when the object to be heated 200 is placed on the translucent top plate 2 changes the amount of external light that enters the housing 1, utilizing the light receiving means provided in the housing 1. It is also possible to detect the load depending on the light receiving state of. The control unit 14 performs load detection and, when detecting that the object to be heated 200 is removed from the heating port 3 to be heated during the induction heating operation, controls the first power supply 11 to stop heating. Then, the control unit 14 drives the second power supply 13 to operate the cooling unit 12 to cool the top plate 2 until it detects that the object to be heated 200 is placed on the heating port 3 again. .

  As described above, in the present embodiment, the induction heating plate 7 including the top plate 2 on which the object 200 to be heated is placed and the flat metal plate arranged so as to face the back surface of the top plate 2. A transformer 8 having a primary power source 11 that outputs a high-frequency current connected to the primary side and an induction heating plate 7 connected to the secondary side; and a top plate driven by a power source supplied from a second power source 13. The cooling part 12 which cools 2 was provided. Therefore, the cooling unit 12 cools the top plate 2 while the heating is stopped, so that the top plate 2 can be quickly used as a work table or a storage table after the heating is stopped, and the usability of the induction heating cooker 100 is greatly improved. Can be improved.

  In addition, when the induction heating cooker 100 has a function of detecting the temperature of the object to be heated 200 by using the output of a temperature detection means such as a thermistor provided on the top plate 2 or an infrared sensor provided in the housing 1. It is known that the temperature of the top plate 2 affects the accuracy of temperature detection of the object to be heated 200. Therefore, it is difficult to accurately detect the temperature of the object to be heated 200 by a so-called hot start in which the induction heating operation is started in a state where the temperature of the top plate 2 is higher than room temperature, and further, the bottom surface of the object to be heated 200 is heated. It is difficult to accurately detect the temperature when the so-called pan warp state is along. However, by cooling the top plate 2 by the cooling unit 12 after the heating is stopped as in the present embodiment, it is easy to perform the next induction heating operation at a so-called cold start in which the temperature of the top plate 2 is at room temperature or close thereto. Become. Therefore, even if the amount of warp of the pan is taken into consideration, the temperature of the object to be heated 200 can be detected more accurately, and the induction heating cooker 100 with good usability can be provided.

Embodiment 2.
FIG. 4 is a diagram showing a configuration of a main part of the induction heating cooker according to the second embodiment. FIG. 5 is a schematic plan view of the induction heating plate of the heating cooker according to the second embodiment. In this embodiment, differences from the first embodiment will be mainly described. In addition to the configuration described in the first embodiment, the present embodiment includes a temperature detector 16 that detects the temperature of either or both of the induction heating plate 7 and the top plate 2. The temperature detector 16 of the present embodiment is, for example, a thermistor attached to the back surface of the induction heating plate 7, directly detects the temperature of the induction heating plate 7, and is further in contact with the induction heating plate 7. The temperature of 2 can also be detected indirectly. In the present embodiment, the case where the temperature detector 16 directly detects the temperature of the induction heating plate 7 will be described as an example, but the temperature detector 16 directly detects the temperature of the top plate 2. May be. Further, the temperature detector 16 may be, for example, an infrared sensor that detects temperature based on infrared rays emitted from the top plate 2 and the induction heating plate 7. The output of the temperature detector 16 is input to the control unit 14.

  The present embodiment is different from the first embodiment in the control regarding the start and stop of the cooling operation by the cooling unit 12.

  FIG. 6 is a flowchart illustrating a cooling operation of the top plate of the induction heating cooker according to the second embodiment. The control unit 14 stops driving the first power supply 11 when the heating stop condition is satisfied (S1). This stops the induction heating operation. When the induction heating operation is stopped, the controller 14 starts monitoring the temperature of the induction heating plate 7 based on the output from the temperature detector 16 (S2). The control unit 14 compares the temperature detected by the temperature detector 16 with the first threshold value (S3). If the detected temperature is less than the first threshold value (S3; NO), the cooling unit 12 is not operated. The process ends. On the other hand, if the temperature detected by the temperature detector 16 is equal to or higher than the first threshold value (S3; YES), the control unit 14 drives the second power supply 13 to supply power to the cooling unit 12, and the cooling unit 12 causes the temperature to rise. The cooling of the plate 2 is started (S4).

  Even after the cooling operation by the cooling unit 12 is started, the control unit 14 continues to monitor the temperature detected by the temperature detector 16, compares the detected temperature with the second threshold value (S5), and the detected temperature becomes equal to the second threshold value. While it exceeds (S5; NO), the cooling operation is continued. On the other hand, if the detected temperature is less than or equal to the second threshold value (S5; YES), the control unit 14 stops driving the second power supply 13 and stops the cooling operation of the top plate 2 by the cooling unit 12 (S6).

  Here, the first threshold is a condition for starting the operation of the cooling unit 12, and the second threshold is a condition for stopping the operation of the cooling unit 12. The second threshold value is a temperature lower than the first threshold value, and specifically, the first threshold value can be, for example, about 40 ° C., and the second threshold value can be, for example, about 25 ° C. In this case, if the temperature of the induction heating plate 7 or the top plate 2 is 40 ° C. or higher, the top plate 2 is cooled by the cooling unit 12, and if the temperature of the induction heating plate 7 or the top plate 2 becomes 25 ° C. or lower, the cooling operation is performed. Stops.

  According to this embodiment, the same effect as that of the first embodiment can be obtained. Further, in the present embodiment, the temperature detector 16 that detects the temperature of the top plate 2 or the induction heating plate 7 is provided, and the control unit 14 stops the induction heating operation and then the detected value of the temperature detector 16 is the first value. When it is equal to or more than the threshold value, the cooling unit 12 is made to perform the cooling operation. That is, if the temperature detected by the temperature detector 16 is less than the first threshold value even after the heating is stopped, the cooling unit 12 does not perform the cooling operation. Further, in the present embodiment, after the cooling operation is started, when the temperature detected by the temperature detector 16 becomes equal to or lower than the second threshold value, the cooling operation is stopped. Therefore, the unnecessary cooling operation by the cooling unit 12 is suppressed, and the power consumption of the induction heating cooker 100 can be reduced.

  In addition, in the present embodiment, an example in which both the first threshold value that is the start condition of the cooling operation and the second threshold value that is the end condition are used has been described, but only the first threshold value that is the start condition of the cooling operation is adopted. The stop of the cooling operation may be determined by the passage of time. In addition, after the heating is stopped, the cooling operation may be started unconditionally, and only the second threshold value that is the cooling operation stop condition may be adopted.

Embodiment 3.
The present embodiment is a modification of the control relating to the start and stop of the cooling operation described in the second embodiment, and here, differences from the second embodiment will be mainly described. In the present embodiment, the display unit 5 performs a display for confirming whether or not the cooling operation by the cooling unit 12 is performed, and the operation unit 4 inputs an instruction as to whether or not the cooling unit 12 is operated. Equipped with input means. The control unit 14 controls the cooling operation based on the input from the operation unit 4. The details will be described below.

  FIG. 7 is a flowchart illustrating a cooling operation of the top plate of the induction heating cooker according to the third embodiment. The control unit 14 stops driving the first power supply 11 when the heating stop condition is satisfied (S11). This stops the induction heating operation. When the induction heating operation is stopped, the control unit 14 starts monitoring the temperature of the induction heating plate 7 based on the output from the temperature detector 16 (S12). The control unit 14 compares the temperature detected by the temperature detector 16 with the first threshold value (S13). If the detected temperature is less than the first threshold value (S13; NO), the cooling unit 12 is not operated. The process ends. On the other hand, if the temperature detected by the temperature detector 16 is equal to or higher than the first threshold value (S13; YES), the control unit 14 causes the display unit 5 to perform a display confirming the necessity of the cooling operation (S14).

  In step S14, the control unit 14 causes the display unit 5 to display a message confirming whether to cool the top plate 2. The operation unit 4 is provided with an input means for inputting the necessity of cooling, and if the control unit 14 does not input to the operation unit 4 that the cooling operation is required (S15; NO), the high temperature caution display unit is displayed. 6 is displayed to display a high temperature warning (S16), and the cooling operation by the cooling unit 12 is not performed.

  On the other hand, when the control unit 14 obtains an input instructing the execution of the cooling operation from the operation unit 4 (S15; YES), it drives the second power supply 13 to supply power to the cooling unit 12, and the cooling unit 12 operates the ceiling. The cooling of the plate 2 is started (S17).

  Even after the cooling operation by the cooling unit 12 is started, the control unit 14 continues to monitor the temperature detected by the temperature detector 16, compares the detected temperature with the second threshold value (S18), and the detected temperature becomes equal to the second threshold value. While exceeding (S18; NO), the cooling operation is continued. On the other hand, if the detected temperature is equal to or lower than the second threshold value (S18; YES), the control unit 14 stops driving the second power supply 13 and stops the cooling operation of the top plate 2 by the cooling unit 12 (S19).

  The display in step S14 and step S16 can be continued until the set time elapses after the induction heating operation is stopped. Alternatively, it can be continued until the temperature detected by the temperature detector 16 becomes equal to or lower than the set temperature.

  According to this embodiment, the same effect as that of the second embodiment can be obtained. Further, in the present embodiment, since the operation unit 4 for inputting the necessity of the cooling operation by the cooling unit 12 is provided, the cooling operation is executed according to the intention of the user. Therefore, the user can select not to cool the top plate 2. Since the top plate 2 has a high temperature after the induction heating operation, when the cooling operation is not performed, the temperature of the top plate 2 gradually decreases, but the high temperature state is maintained for a while. Therefore, by placing the object to be heated 200 on the top plate 2, the heat insulating function can be exerted on the top plate 2 even when the induction heating operation is stopped, and the power consumption related to heating is suppressed. Thus, the induction heating cooker 100 can be obtained that can be economically used.

Fourth Embodiment
The present embodiment is a modification of the control relating to the start and stop of the cooling operation described in the second embodiment, and here, differences from the second embodiment will be mainly described. In the present embodiment, the operation unit 4 is provided with input means for inputting an instruction regarding whether or not to perform the cooling operation by the cooling unit 12. The control unit 14 controls the cooling operation based on the input from the operation unit 4. The details will be described below.

  FIG. 8 is a flowchart illustrating a cooling operation of the top plate of the induction heating cooker according to the fourth embodiment. The control unit 14 is in the heating stopped state because the heating stop condition is satisfied and the first power supply 11 is stopped to be driven (S21). The control unit 14 monitors the instruction to execute the cooling from the operation unit 4 (S22), and if there is no cooling instruction (S22; NO), does not perform the subsequent processing.

  On the other hand, when receiving an instruction from the operation unit 4 to execute cooling (S22; YES), the control unit 14 detects whether or not there is a placed object on the top plate 2 (S23). Here, the placed object can be detected by the load detection process described in the first embodiment. In addition, a weight sensor that detects the load related to the top plate 2 may be provided, and the control unit 14 may detect whether or not there is a placed object on the top plate 2 based on the output from the weight sensor.

  When the control unit 14 determines that there is no mounted object on the top plate 2 (S23; NO), the cooling operation is not performed and the process ends. On the other hand, when the control unit 14 determines that there is a mounted object on the top plate 2 (S23; YES), it drives the second power supply 13 to supply power to the cooling unit 12, and the cooling unit 12 causes the cooling unit 12 to operate. Cooling of the top plate 2 is started (S24). After starting the cooling operation, the control unit 14 continues the cooling operation if there is no cooling stop instruction from the operation unit 4 (S25; NO), and acquires the cooling stop instruction from the operation unit 4 (S25; YES), The driving of the second power supply 13 is stopped to stop the cooling of the top plate 2 (S26).

  In FIG. 8, an example of detecting whether or not there is a placed object on the top plate 2 in step S23 has been described, but this step is not provided and the operation unit 4 is instructed to start and stop cooling. The top plate 2 may be cooled only based on the above.

  According to this embodiment, the same effect as that of the first embodiment can be obtained. Further, in the present embodiment, the top plate 2 can be cooled based on the input to the operation unit 4 regardless of the temperatures of the top plate 2 and the induction heating plate 7. Therefore, for example, when the top plate 2 is at room temperature, the user can positively operate the cooling unit 12 to cool the top plate 2, thereby cooling the placed object on the top plate 2. Therefore, it is possible to cool the food placed on the top plate 2 and suppress the growth of bacteria. Although the cooked food may lose its deliciousness as a food ingredient with the passage of time, the flavor, taste, nutritional value, etc. of the cooked food can be maintained by cooling with the cooling unit 12. Will also be possible. For example, when a Peltier element is used as the cooling unit 12, it is possible to cool down to a minus temperature zone, so that the object placed on the top plate 2 can be rapidly cooled.

Embodiment 5.
In the present embodiment, a modification of the arrangement of the cooling unit 12 will be described, focusing on the differences from the second embodiment. This embodiment can be combined with any of Embodiments 1 to 4.

  FIG. 9: is a figure which shows the structure of the principal part of the induction heating cooking appliance which concerns on Embodiment 5. As shown in FIG. In addition to the configuration described in the second embodiment, the present embodiment includes a movable unit 17 as an adjusting unit that adjusts the distance between the induction heating plate 7 and the cooling unit 12. The movable unit 17 mechanically moves the cooling unit 12 up and down to adjust the distance between the cooling unit 12 and the induction heating plate 7. Based on the control signal from the control unit 14, the movable unit 17 moves in the vertical direction, and accordingly, the cooling unit 12 mechanically connected to the movable unit 17 also moves in the vertical direction. The cooling unit 12 moves between a state in which the induction heating plate 7 is in contact (zero gap) and a state in which a gap of, for example, about 1 to 2 mm is provided between the cooling unit 12 and the induction heating plate 7. The specific distance between the cooling unit 12 and the induction heating plate 7 is an example.

  In such a configuration, the control unit 14 controls the movable means 17 to move the cooling unit 12 downward when performing the induction heating operation, that is, when the cooling unit 12 does not perform the cooling operation. A gap is provided between the cooling unit 12 and the induction heating plate 7. On the other hand, when the induction heating operation is not performed, that is, when the cooling unit 12 is performing the cooling operation, the control unit 14 controls the movable means 17 to move the cooling unit 12 upward to perform the cooling operation. The distance of the gap is made smaller than that in the case where the cooling unit 12 and the induction heating plate 7 are brought into contact with each other.

  According to the present embodiment, since the cooling unit 12 can be separated from the induction heating plate 7 during the induction heating operation, it is difficult for the cooling unit 12 to receive heat from the induction heating plate 7 and the cooling unit It is possible to suppress deterioration of 12 due to heat. Therefore, the life of the cooling unit 12 can be extended. When the cooling operation is performed, the cooling unit 12 is brought into contact with the induction heating plate 7 so that the top plate 2 can be effectively cooled via the induction heating plate 7. In the present embodiment, the cooling unit 12 is described as being brought into contact with the induction heating plate 7 when performing the cooling operation, but it is not necessary to make contact with the induction heating plate 7, and the distance between the two is set so as to obtain a desired cooling effect. You may bring it close.

Sixth Embodiment
In the present embodiment, a modification of the arrangement of the cooling unit 12 will be described, focusing on the differences from the second embodiment. This embodiment can be combined with any of Embodiments 1 to 5.

  FIG. 10 is a schematic plan view of the induction heating plate of the induction heating cooker according to the sixth embodiment. In the induction heating plate 7A shown in FIG. 10, a plurality of openings 18A penetrating the flat plate surface of the induction heating plate 7 are formed, and the cooling unit 12 is arranged in the openings 18A. Although the rectangular opening 18A is illustrated in FIG. 10, the specific shape of the opening 18A is not limited as long as the cooling section 12 can be arranged inside.

  FIG. 11 is a schematic plan view showing another example of the induction heating plate of the induction heating cooker according to the sixth embodiment. The induction heating plate 7B shown in FIG. 11 is provided with an annular opening 18B penetrating its flat plate surface. It can be said that the induction heating plate 7B has a flat plate surface formed in a double annular shape. The double annular induction heating plate 7B is directly connected or connected in parallel in the transformer 8. Alternatively, the transformer 8 may individually output to each of the double annular induction heating plates 7B. And the cooling part 12 is arrange | positioned in the opening part 18B. Note that the specific shape of the opening 18B is an example, and the specific shape of the opening 18B is not limited as long as the cooling section 12 can be arranged inside.

  FIG. 12: is a schematic diagram explaining the principal part cross section of the induction heating cooking appliance which concerns on Embodiment 6. As shown in FIG. FIG. 12 shows a schematic cross section of the example shown in FIG. As shown in FIG. 12, the cooling unit 12 is arranged inside the opening 18A in contact with the back surface of the top plate 2. Therefore, the cooling unit 12 can directly cool the top plate 2. Similarly in the example shown in FIG. 11, the cooling unit 12 is arranged inside the opening 18 </ b> B in contact with the back surface of the top plate 2.

  According to the present embodiment, since the cooling unit 12 is brought into direct contact with the top plate 2, the cooling effect of the top plate 2 can be further enhanced. Further, since the cooling unit 12 is arranged apart from the induction heating plates 7A and 7B, it is difficult for the cooling unit 12 to receive heat from the induction heating plates 7A and 7B, and deterioration of the cooling unit 12 due to heat can be suppressed. Therefore, the life of the cooling unit 12 can be extended. Further, since the cooling unit 12 is arranged so as to partially or entirely overlap the thickness of the induction heating plates 7A and 7B, as compared with the case where the cooling unit 12 is arranged on the induction heating plate, the top plate 2, The overall thickness of the induction heating plates 7A and 7B and the cooling unit 12 can be reduced. Therefore, the induction heating cooker 100 can be made thinner.

  1 case, 2 top plate, 3 heating port, 4 operation part, 5 display part, 6 high temperature caution display part, 7 induction heating plate, 7A induction heating plate, 7B induction heating plate, 8 transformer, 9 magnetic material, 10 Coil, 11 1st power supply, 12 cooling part, 13 2nd power supply, 14 control part, 15 magnetic material, 16 temperature detector, 17 movable means, 18A opening, 18B opening, 20 winding number, 71 vertical part, 100 induction Heating cooker, 200 objects to be heated.

Claims (10)

A top plate on which the object to be heated is placed,
A first power supply that outputs a high frequency current;
A second power supply,
An induction heating plate composed of a flat plate-shaped conductive material arranged facing the back surface of the top plate,
A transformer in which the first power source is connected to the primary side and the induction heating plate is connected to the secondary side;
A cooling unit that is in contact with the induction heating plate and is driven by a power supply supplied from the second power supply to cool the top plate;
An induction heating cooker, wherein the high-frequency current output from the first power source and the operation of the cooling unit are controlled based on the presence or absence of the object to be heated on the top plate. A top plate on which the object to be heated is placed,
A first power supply that outputs a high frequency current;
A second power supply,
An induction heating plate composed of a flat plate-shaped conductive material arranged facing the back surface of the top plate,
A transformer in which the first power source is connected to the primary side and the induction heating plate is connected to the secondary side;
A cooling unit that is driven by a power supply supplied from the second power supply to cool the top plate;
An adjusting unit for adjusting the distance between the induction heating plate and the cooling unit,
Based on the presence or absence of the object to be heated on the top plate, the high-frequency current output from the first power source and the operation of the cooling unit are controlled,
The cooling unit is arranged at a position overlapping the induction heating plate in a plan view,
Induction heating, characterized in that the adjustment unit makes the distance between the induction heating plate and the cooling unit larger when the cooling unit is not performing the cooling operation than when the cooling operation is being performed. Cooking device. The induction heating cooker according to claim 2, wherein the adjusting unit brings the cooling unit and the induction heating plate into contact with each other when the cooling unit is performing a cooling operation. When it is detected that there is no object to be heated on the top plate while the first power source is outputting the high frequency current, the first power source stops the output of the high frequency current and the cooling is performed. The part starts a cooling operation. The induction heating cooker according to any one of claims 1 to 3 , wherein the part starts a cooling operation. An operation unit for inputting an instruction to start the cooling operation by the cooling unit,
When an instruction to start the cooling operation by the cooling unit is input from the operation unit,
When it is detected that there is an object to be heated on the top plate, the cooling unit starts a cooling operation,
The induction unit according to any one of claims 1 to 4 , wherein the cooling unit does not start a cooling operation when it is detected that there is no object to be heated on the top plate. Heating cooker. The presence or absence of an object to be heated on the top plate is detected based on a value of a current flowing through the induction heating plate when a high-frequency current is supplied to the induction heating plate. Item 6. The induction heating cooker according to any one of items 5 . The top plate has translucency,
On the lower side of the top plate, a light receiving means for receiving external light through the top plate is provided,
The induction heating cooker according to any one of claims 1 to 5 , wherein the light receiving unit detects the presence or absence of an object to be heated on the top plate based on a light receiving state. A weight sensor for detecting a load applied to the top plate is provided,
The induction heating cooker according to any one of claims 1 to 5 , wherein the presence or absence of the object to be heated on the top plate is detected based on the output from the weight sensor. A temperature detector for detecting the temperature of the top plate or the induction heating plate,
The cooling unit executes a cooling operation after the first power supply has stopped outputting high-frequency current and when the output of the temperature detector is equal to or higher than a first threshold value. ~ The induction heating cooker according to claim 8 . The induction heating cooker according to claim 9 , wherein the cooling unit stops the cooling operation when the output of the temperature detector is equal to or less than a second threshold value that is a value smaller than the first threshold value.

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