JP2010049959A - Induction heating cooker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a safe and conveniently usable induction heating cooker in which a cooking appliance with any shape and size can be used, temperature of the cooking appliance can be detected with non-contact and high precision, and heating of the cooking appliance can be controlled automatically based on this detected temperature information. <P>SOLUTION: The induction-heating cooker has a top plate 2 on which the cooker 20 for heating cooking materials is placed, a heating coil 3 which is installed on a lower face side of the top plate 2 and generates an induction magnetic field in order to heat the cooker 20, a temperature detecting means 4 which is installed on the top plate 2, detects the temperature of the cooking appliance 20 which is placed on the top plate 2, installed by a transmitting and receiving means 6, 8 which is arranged on the lower face side of the top plate 2 and receives temperature information from the temperature detecting means 4, and is equipped with a control means 5 which controls a supply-current to the heating coil 3 based on the temperature information. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an induction heating cooker, and more particularly to an induction heating cooker that automatically controls heating of a cooking utensil by detecting the temperature of the cooking utensil.

  An external temperature sensor is fixed to a conventional cooking device that is not affected by the magnetic field from the IH coil and does not include a top plate, and temperature information corresponding to the detection result of the external temperature sensor is transmitted by infrared. By controlling the cooking contents based on the cooking temperature, the actual temperature of the cooking utensil can be detected with high accuracy without performing step-down control of the heating power, thereby continuously heating the cooking utensil with high heating power. There is one that can finish a cooked product in a desired state in a short time (see, for example, Patent Document 1).

  Further, a top plate on which the cooking container is placed, a heating coil that generates an induction magnetic field to heat the cooking container, an infrared sensor that detects the temperature of the cooking utensil via the top plate, and temperature information of the infrared sensor By providing a heating control means for driving and controlling the high-frequency current of the heating coil and detecting the temperature of the cooking container so that the light reception sensitivity wavelength range of the infrared sensor overlaps the infrared transmission wavelength range of the top plate, the responsiveness is improved. There is an induction heating cooker which controls the temperature of a cooking container (for example, refer to patent documents 2).

Japanese Patent Laying-Open No. 2005-158407 (page 6-7, FIG. 2) JP 2007-71771 A (page 4-5, FIG. 1)

  According to the heating cooker of Patent Document 1, the temperature of the cooking utensil can be directly detected, but a dedicated cooking utensil to which an external temperature sensor is fixed must be used, and any cooking utensil can be used. There was a problem that it was extremely inconvenient and unusable because it was not possible. Also, the temperature detected by the external temperature sensor is transmitted through the top plate using infrared light and transmitted to the infrared light receiving circuit provided under the top plate, so that a top plate that cannot transmit infrared light cannot be used. There was a problem.

  Moreover, in the induction heating cooker of patent document 2, since the light reception sensitivity wavelength range of the infrared sensor overlaps with the infrared transmission wavelength range of the top plate, when a colored top plate that is difficult to transmit infrared rays is used. There was a problem that it was difficult to detect the temperature of the cooking container.

  The present invention has been made to solve the above-described problem, and can use a cooking utensil having an arbitrary shape and size. The temperature of the cooking utensil is detected in a non-contact and highly accurate manner. The purpose of the present invention is to provide a safe and easy-to-use induction heating cooker that automatically controls the heating of cooking utensils based on the above.

  An induction heating cooker according to the present invention includes a top plate on which a cooking utensil for heating an object to be cooked is placed, and an induction magnetic field that is provided on the lower surface side of the top plate to heat the cooking utensil. A heating coil; temperature detection means for detecting the temperature of the cooking utensil placed on the top plate and placed on the top plate; and a temperature from the temperature detection means arranged on the lower surface side of the top plate And a transmission / reception means for receiving information, and a control means for controlling energization to the heating coil based on the temperature information.

  According to the present invention, since the temperature detection means of the cooking utensil is provided on the top plate, a cooking utensil of any size and shape can be used, and one or more temperature detection means are provided in the vicinity of the cooking utensil. Therefore, it is possible to improve the temperature detection accuracy of the cooking utensil, and thereby reliably suppress an abnormal temperature rise of the cooking utensil, so that an induction heating cooker that is safe and easy to use can be obtained.

[Embodiment 1]
FIG. 1 is a configuration explanatory diagram of a main part of the induction heating cooker according to Embodiment 1 of the present invention.
In the figure, the induction heating cooker 1 is made of a non-magnetic material, is provided on the top plate 2 on which the cooking utensil 20 to be cooked is placed and heated, and on the lower surface side of the top plate 2. The heating coil 3 that generates an induction magnetic field for heating the cooking utensil 20, the temperature detection unit 4 that is installed on the top plate 2 and detects the temperature of the cooking utensil 20, and the temperature information from the temperature detection unit 4 And a control means 5 for controlling the current supplied to the heating coil 3 from an inverter circuit (not shown).

Reference numeral 6 denotes a first coil disposed on the lower surface side of the top plate 2 so as to face the temperature detecting means, and reference numeral 8 denotes a first coil disposed on the lower surface side of the top plate 2 and performing communication via the first coil 6. These communication means are connected to the control means 5, and the first coil 6 and the first communication means 8 constitute the transmission / reception means of the control means 5.
The temperature detection means 4 includes a second coil 7 disposed on the top plate 2 so as to face the first coil 6, a second communication means 9 for performing communication via the second coil 7, and a cooking utensil. It has a temperature sensor 10 for detecting the temperature of 20, and is housed in a case 11 made of a nonmagnetic material.

The temperature detection means 4 is not electrically connected to the control means 5 by wiring, and is connected by electromagnetic induction coupling between the first coil 6 and the second coil 7 to transmit and receive power. Signal exchange takes place.
The temperature sensor 10 is an element capable of detecting the temperature in a non-contact manner with respect to the cooking utensil 20, for example, an infrared sensor made of a photodiode or the like. The temperature detecting means 4 having the temperature sensor 10 may be fixed to the top plate 2 or may be detachably installed on the top plate 2.

Next, the effect | action of the induction heating cooking appliance 1 which concerns on this Embodiment comprised as mentioned above is demonstrated.
When the user requests a heating operation (cooking switch ON) for the cooking utensil 20 placed on the top plate 2, the control means 5 sends an alternating current to the heating coil 3 from the inverter circuit and heats it. An induction magnetic field is generated in the coil 3. An eddy current flows in the cooking utensil 20 due to the generated induced magnetic field, Joule heat is generated in the cooking utensil 20 by this eddy current, and the cooking utensil 20 is heated.

  At this time, the infrared sensor 10 (temperature sensor) provided in the temperature detection means 4 detects thermal energy radiated from the heated cooking utensil 20 and converts it into a voltage signal or a current signal. The voltage signal or current signal obtained by the infrared sensor 10 is converted from an analog signal into a digital signal in the second communication means 9, and the second signal means 9 to the second coil 7, the first coil 6, 1 is transmitted to the control means 5 as a communication signal including temperature information.

  In the control means 5, the temperature of the cooking utensil 20 is calculated by calculation from the communication signal including the temperature information transmitted from the temperature detection means 4. And based on the temperature of the cooking utensil 20 obtained in this way, the control means 5 controls the electric current which flows into the heating coil 3, and performs the thermal power adjustment with respect to the cooking utensil 20 according to the progress of cooking.

  Next, the communication operation between the temperature detection unit 4 and the control unit 5 will be described. By supplying an alternating current from the first communication means 8 to the first coil 6, an induced magnetic field is generated in the first coil 6. This induced magnetic field changes the magnetic flux interlinking with the second coil 7, and an electromotive force is generated in the second coil 7 by electromagnetic induction. The second communication means 9 is used as a power source for the temperature detection means 4 including the second communication means 9 by converting the electromotive force into DC power.

  Here, the case of using the induction magnetic field generated from the first coil 6 as the power supply unit of the temperature detection unit 4 is shown, but the induction coil generates a magnetic induction field for heating the cooking utensil 20 in the heating coil 3 as well. By receiving the induction magnetic field generated from the heating coil 3 by the second coil 7, this may be used as a power source for the temperature detection means 4. In this case, a circuit for supplying power to the temperature detecting unit 4 by the first communication unit 8 and an operation for supplying power are not required.

  The first communication means 8 generates an induction magnetic field from the first coil 6 by supplying an alternating current to the first coil 6 based on a communication signal transmitted from the control means 5 to the temperature detection means 4. Let This induced magnetic field changes the magnetic flux interlinking with the second coil 7, and an electromotive force is generated in the second coil 7 by electromagnetic induction. The second communication means 9 detects this electromotive force and extracts a communication component to receive a communication signal from the control means 5. In this way, communication from the control means 5 to the temperature detection means 4 is performed.

  Similarly, the second communication unit 9 transmits temperature information of the cooking utensil 20 detected by the temperature sensor 10 of the temperature detection unit 4 to the control unit 5. The second communication means 9 generates an induction magnetic field in the second coil 7 by controlling the current flowing through the second coil 7 based on the communication signal including the temperature information. The magnetic flux interlinked with the first coil 6 is changed by the induced magnetic field, and an electromotive force is generated in the first coil 6 by the electromagnetic induction. The first communication means 8 detects this electromotive force and receives the communication signal from the temperature detection means 4 by extracting the communication signal component. In this way, communication from the temperature detection means 4 to the control means 5 is performed.

  Here, although the 1st coil 6 and the 2nd coil 7 are coils which consist of a winding like the heating coil 3, the electric power used is smaller than the heating coil 3. FIG. The temperature detection means 4 is smaller than the cooking utensil 20. Therefore, since the induction magnetic field generated from the heating coil 3 can be considered to interfere with the electromagnetic induction coupling between the second coil 7 of the temperature detection means 4 and the first coil 6, the heating coil 3. It is desirable that the frequency of the induced magnetic field generated from the first magnetic field and the frequency of the induced magnetic field used for power supply or communication between the first coil 6 and the second coil 7 are different from each other.

  In communication, as the frequency of the induced magnetic field is increased, the communication speed can be increased, and the first coil 6 and the second coil 7 can be made smaller. The frequency of the induction magnetic field used between the first coil 6 and the second coil 7 may be made higher than the frequency of the induction magnetic field of the heating coil 3. For these reasons, the diameters of the first coil 6 and the second coil 7 are smaller than the diameter of the heating coil 3.

  When the same frequency is used as the frequency of the induction magnetic field for power transmission and the frequency of the induction magnetic field for communication in the first coil 6 and the second coil 7, there is a method of superimposing a communication signal on the induction magnetic field for power transmission. Though possible, examples of modulation schemes used in this case include ASK (Amplitude Shift Keying), PSK (Phase Shift Keying), FSK (Frequency Shift Keying), and QAM (Quadrature Amplitude Modulation). FIG. 2 (a) shows the communication signal waveform, FIG. 2 (b) shows the ASK method, FIG. 2 (c) shows the PSK method, and FIG. 2 (d) shows the first and second coils. An example of 6 and 7 current waveforms is shown.

  In the above description, the case where the same frequency is used as the frequency of the induction magnetic field of the first coil 6 and the second coil 7 is shown, but different frequencies may be used. In this case, the first coil 6 and the second coil 7 may be composed of a plurality of independent coils for power transmission and communication.

  According to the present embodiment, since the temperature detection means 4 of the cooking utensil 20 is provided on the top plate 2, the degree of freedom of arrangement of the temperature detection means 4 can be increased. Moreover, since it is not necessary to provide a temperature detection means in the cooking appliance 20, the magnitude | size, shape, etc. of the cooking appliance 20 can be selected arbitrarily and can be used. Furthermore, by installing the temperature detection means 4 in the vicinity of the cooking utensil 20, the temperature detection accuracy of the cooking utensil 20 can be increased, and thereby an abnormal temperature rise due to empty cooking of the cooking utensil 20 can be suppressed. You can get an easy-to-use induction heating cooker.

  In addition, when the user shakes the cooking utensil 20 up and down, left and right in order to stir the cooking object during cooking, the cooking utensil 20 may move away from the top plate 2, but in such a case, A decrease in the temperature detection accuracy of the cooking utensil 20 can be prevented.

  In addition, since power and signals are exchanged between the temperature detection means 4 and the control means 5 by electromagnetic induction coupling between the first coil 6 and the second coil 7, the top plate 2 There is no need to provide a hole for wiring to connect the two. For this reason, since the liquid spilled on the top plate 2 does not enter the inside through the hole, it is possible to improve the antifouling property of the top plate 2 and to prevent deterioration of internal devices and wiring. Can be improved. Moreover, since the material which does not permeate | transmit infrared rays can also be used for the top plate 2, the freedom degree of selection of the top plate 2 can be raised.

  Further, since no electrical connection terminal or connection is required for the temperature detection means 4, durability and reliability based on deterioration of the terminal and wiring can be improved, and the sealing performance of the temperature detection means 4 can be improved. Dustproofness and waterproofness can be improved.

[Embodiment 2]
FIG. 3 is a perspective view schematically showing an induction heating cooker according to Embodiment 2 of the present invention, and FIG. 4 is a configuration explanatory view of the main part of FIG. The same parts as those in the first embodiment are denoted by the same reference numerals.
In FIG. 3, reference numerals 11a, 11b, and 11c (hereinafter simply referred to as “11”) denote placement parts for the cooking utensil 20 provided on the upper surface of the top plate 2; Heating coils 3a, 3b, 3c (however, 3c may be a heater) are provided. Therefore, in the following description, the placement portions 11a to 11c may be referred to as heating coils 3a to 3c. Reference numeral 12 denotes a display operation unit which is provided on the top plate 2 and performs operation and operation display of the induction heating cooker 1.

In the present embodiment, a plurality of temperature detecting means 4a and 4b are provided in the vicinity of each or a part of the placement portions 11a to 11c of the top plate 2 (in the vicinity of the placement portion 11b in the figure). In this example, two coils 7a and 7b, second communication means 9a and 9b, and temperature sensors 10a and 10b are provided.
Further, on the lower surface side of the top plate 2, first coils 6a and 6b and first communication means 8a and 8b are provided facing the first and second temperature detecting means 4a and 4b.

In the induction heating cooker 1, the cooking utensil 20 is placed on the placement unit 11 provided on the top plate 2. However, the cooking utensil 20 is not necessarily installed at an ideal position, and the cooking utensil 20 to be used is used. Depending on the shape, the distance from the temperature detecting means 4 varies.
Therefore, in the present embodiment, the temperature of the cooking utensil 20 is detected by the plurality of temperature detection means 4a and 4b, and the temperature of the cooking utensil 20 is determined based on the temperature information obtained from each temperature detection means 4a and 4b. The temperature detection error is corrected according to the arrangement position and shape.

The temperature detection operation of the temperature detection means 4a and 4b and the signal transmission operation to the control means 5 in the present embodiment are the same as those in the first embodiment.
The control means 5 calculates the correction amount of the temperature of the cooking utensil 20 from a plurality of digital data of communication signals including temperature information detected by the temperature sensors 10a and 10b transmitted from the plurality of temperature detection means 4a and 4b. Then, the temperature of the cooking utensil 20 is derived. And based on the temperature of the cooking utensil 20 obtained in this way, the control means 5 controls the electric current supplied to the heating coil 3, and performs the thermal power adjustment with respect to the cooking utensil 20 according to the progress of cooking.

In the above description, the first communication means 8a and 8b are provided in the first coils 6a and 6b, respectively. However, two first coils 6a and 6b are provided in one first communication means 8. They may be connected and switched to be used corresponding to the first coil 6a or 6b to be used.
In the present embodiment, the same effect as in the first embodiment can be obtained, but the temperature detected by the plurality of temperature detecting means 4 is corrected to obtain the temperature of the cooking utensil 20. Therefore, the temperature detection accuracy can be further increased.

[Embodiment 3]
FIG. 5 is a perspective view schematically showing an induction heating cooker according to Embodiment 3 of the present invention, and FIG. 6 is a configuration explanatory view of the main part of FIG. The same parts as those in the second embodiment are denoted by the same reference numerals.
In the present embodiment, a plurality of first coils 6 are provided in the vicinity of the heating coils 3 a to 3 b on the lower surface side of the top plate 2, and one or more are provided on the first coil 6 on the upper surface of the top plate 2. The temperature detecting means 4 is detachably installed.

  In this case, as shown in FIG. 6, each first coil 6a, 6b,... May be provided with first communication means 8a, 8b,. A plurality of first coils 6a, 6b,... May be connected, and the first communication means 8 may be switched and used corresponding to the first coil 6 to be used.

In the present embodiment, the placement units 11a to 11c (heating coils 3a to 3c) according to the shape and size of the cooking utensil 20 placed on the placement units 11a to 11c provided on the top plate 2. ), One or a plurality of temperature detecting means 4 are installed above the plurality of first coils 6 provided in the vicinity of
On the other hand, the first communication means 8 obtains position information of the one or more first coils 6 connected to the first communication means 8 with respect to the top plate 2 or solid identification information for identifying the position information. The position information or the solid identification information is added to the temperature information detected by the temperature detection means 4 and transmitted to the control means 5 as in the case of the first embodiment. The following operations are the same as those in the first and second embodiments.

Here, there may be a case where the temperature detecting means 4 is less than the first coil 6, in which case the determination is performed as follows.
In order to confirm whether or not the temperature detecting means 4 is present on the first coil 6, electric power and AC current for communication are supplied to the first coil 6 connected to the first communication means 8. Supply. If the temperature detection means 4 is present on the first coil 6, response communication is obtained from the temperature detection means 4. Therefore, it is determined that the temperature detection means 4 is present on the first coil 6, and the temperature detection means 4. Continue to supply and communicate with

  On the other hand, when the temperature detection unit 4 does not exist on the first coil 6, a response signal cannot be obtained from the temperature detection unit 4, so it is determined that the temperature detection unit 4 does not exist on the first coil 6. Then, power supply and communication to the temperature detection means 4 are stopped. In addition, since the installation position of the temperature detection means 4 may change, it is desirable that the operation for confirming the presence of the temperature detection means 4 on the first coil 6 is continuously performed at a predetermined interval.

  In the present embodiment, substantially the same effect as in the first and second embodiments can be obtained, but further, the shape and size of the cooking utensil 20 and the temperature detection in the vicinity thereof corresponding to the placement position. Since the means 4 can be installed, the temperature detection accuracy of the cooking utensil 20 can be further increased.

[Embodiment 4]
FIG. 7 is a perspective view schematically showing an induction heating cooker according to Embodiment 4 of the present invention, and FIG. 8 is a configuration explanatory view of the main part of FIG. The same parts as those in the second embodiment are denoted by the same reference numerals.
In this embodiment, the temperature detection means 4 and the display operation unit 12 are integrated to form a display operation unit 13 with a temperature detection function, which is fixed on the top plate 2 or detachably installed on the top plate 2. It is what you do. On the lower surface side of the top plate 2, the first coil 6 and the first communication means 8 are disposed at one or a plurality of locations in the vicinity of the heating coils 3a to 3c.

  This display operation part 13 with a temperature detection function is provided with the 2nd coil 7, the 2nd communication means 9, and the temperature sensor 10 similarly to the temperature detection means 4 of Embodiment 1-3, and is used. Input means such as a switch, a touch panel, and a microphone for inputting a user's operation instructions, a display device that informs the user of the operation state of the induction heating cooker 1, output means such as sound output means, vibration output means, and the like. It includes a display operation unit control means for controlling.

In this Embodiment, the display operation part 13 with a temperature detection function is fixed to the upper surface of the top plate 2 facing the 1st coil 6 provided in the lower surface side of the top plate 2 of the induction heating cooking appliance 1, Or it is installed so that attachment or detachment is possible.
As in the temperature detection means 4 of the first to third embodiments, the driving power of the display device 13 with a temperature detection function is obtained by using the second coil 7 by the induced magnetic flux generated from the first coil 6 or the heating coil 3. Supplied through.

  Further, the input signal from the display operation unit 13 with the temperature detection function or the output signal to the display operation unit 13 with the temperature detection function uses the temperature information detected by the temperature detection unit 4 according to the first to third embodiments as the control unit 5. As in the case of transmission to the network, bidirectional communication is performed via the second communication means 9, the second coil 7, the first coil 6, and the first communication means 8. In addition, communication information is transmitted between the first coil 6 and the second coil 7 by electromagnetic induction coupling.

  In the present embodiment, substantially the same effects as those of the first to third embodiments can be obtained. However, the temperature detection means 4 and the display operation unit 12 are integrated into a display operation with a temperature detection function. Since the portion 13 is configured and fixed to the top plate 2 or detachably installed on the top plate 2, the top surface structure of the induction heating cooker 1 can be simplified and made compact.

  The temperature detection means 4 according to the present invention and the configuration of power and signal transmission / reception between the temperature detection means 4 and the control means 5 include temperature detection means and a display / operation unit in household electric appliances, and temperature detection means in an air conditioner. And can be used for remote control devices.

It is composition explanatory drawing of the principal part of the induction heating cooking appliance which concerns on Embodiment 1 of this invention. FIG. 3 is a communication waveform diagram according to the first embodiment. It is a typical perspective view of the induction heating cooking appliance which concerns on Embodiment 2 of this invention. FIG. 4 is a configuration explanatory diagram of a main part of FIG. 3. It is a typical perspective view of the induction heating cooking appliance which concerns on Embodiment 3 of this invention. FIG. 6 is a configuration explanatory diagram of a main part of FIG. 5. It is a typical perspective view of the induction heating cooking appliance which concerns on Embodiment 4 of this invention. FIG. 8 is a configuration explanatory diagram of a main part of FIG. 7.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Induction heating cooker, 2 Top plate, 3 Heating coil, 4 Temperature detection means, 5 Control means, 6 1st coil, 7 2nd coil, 8 1st communication means, 9 2nd communication means, 10 Temperature sensor (infrared sensor), 12 display operation unit, 13 display operation unit with temperature detection function.

Claims (12)

  A top plate on which a cooking utensil for heating an object to be cooked is placed, a heating coil provided on the lower surface side of the top plate for generating an induction magnetic field to heat the cooking utensil, and installed on the top plate And a temperature detection means for detecting the temperature of the cooking utensil placed on the top plate, and a transmission / reception means arranged on the lower surface side of the top plate for receiving temperature information from the temperature detection means, An induction heating cooker comprising control means for controlling energization to the heating coil based on the temperature information.   The transmission / reception means of the control means includes a first coil and a first communication means for performing communication via the first coil, and the temperature detection means is a second coil disposed opposite to the first coil. The induction heating cooker according to claim 1, comprising a second communication means for performing communication via the second coil, and a temperature sensor for detecting the temperature of the cooking utensil.   The induction heating cooker according to claim 1 or 2, wherein the temperature detection means is detachable from the top plate.   The induction heating cooker according to claim 2 or 3, wherein the first coil and the second coil are coupled by electromagnetic inductive coupling to supply power and transmit / receive a communication signal.   The induction heating cooker according to any one of claims 2 to 4, wherein the temperature sensor of the temperature detecting means is an infrared sensor.   The induction heating cooker according to any one of claims 2 to 5, wherein the first coil and the second coil have a smaller diameter than the heating coil.   The frequency of the induction magnetic field used for communication between the first coil and the second coil is different from the frequency of the induction magnetic field used for the heating coil. The induction heating cooker in any one.   The frequency of the induction magnetic field used for communication between the first coil and the second coil is higher than the frequency of the induction magnetic field used for the heating coil. The induction heating cooker in any one.   The induction heating cooker according to any one of claims 2 to 8, wherein the first coil is disposed at a plurality of positions on a lower surface side of the top plate.   The induction heating cooker according to claim 9, wherein the temperature detection means can be installed at any position facing the two or more first coils arranged at the plurality of positions.   The induction heating cooker according to claim 9 or 10, wherein a plurality of the temperature detection means are provided, and are installed at two or more positions facing the first coil.   The induction heating cooker according to any one of claims 1 to 11, wherein the temperature detection means is integrated with a display operation unit.

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