JP6328572B2 - Induction heating cooker with non-contact power feeding function and control method thereof - Google Patents

Description

  The present invention relates to an induction heating cooker with a non-contact power feeding function and a method for controlling the same, which can induction-heat cooking utensils such as pots and can supply power to a power receiving device by magnetic field coupling.

  An induction heating cooker supplies a high-frequency current of 20 kHz to 100 kHz to a coil, links a magnetic flux generated by the coil to a metal heated object such as a pan or a pan, and induction-heats the heated object It is. Since the principle of induction heating is electromagnetic induction, electric power can be supplied to the power receiving device by arranging a power receiving device including a power receiving coil instead of the object to be heated. In the present application, feeding power to a power receiving device as a load without using a power line by using a magnetic flux or a magnetic field is referred to as magnetic field coupling type non-contact power feeding or simply non-contact power feeding. That is, the term “non-contact” in this application does not mean physical separation between devices.

  Magnetic coupling type non-contact power feeding can be further classified into non-contact power feeding such as electromagnetic induction type, magnetic field resonance type, magnetic field resonance type, etc., but these are in principle non-contact power feeding based on the law of electromagnetic induction. Therefore, it is appropriate to treat the same as a magnetic field coupling type non-contact power feeding, and it is becoming common. Accordingly, the term “non-contact power supply” in this application refers to a magnetic field coupling type non-contact power supply including a non-contact power supply such as an electromagnetic induction type, a magnetic field resonance type, and a magnetic field resonance type unless otherwise specified.

  For example, the induction heating cooker with a non-contact power feeding function described in Patent Document 1 is a heated object such as a pan that the load placed on the top plate of the induction heating cooker should be induction-heated, or non-contact The inverter is controlled so as to determine whether it is a power receiving device such as a juicer mixer to be fed, and to reduce the supply power when the load is determined as the power receiving device as compared with when it is determined as the object to be heated. The power receiving device receives high-frequency power (for example, about 100 W) output from the primary coil of the induction heating cooker by the secondary coil of the power receiving device, and converts it into DC power by an electric circuit such as a rectifier of the power receiving device or a smoothing capacitor. Rectification is performed to operate a DC motor or the like provided in the power receiving device (see paragraph [0035] of the specification of Patent Document 1).

International Patent Application Publication No. 2013/094174 Pamphlet

  Thus, when the conventional induction heating cooker with a non-contact power feeding function determines whether the load on the top plate is an object to be heated that is induction-heated or a power receiving device that is to be contactlessly powered, and is determined as a power receiving device Since the supplied power is reduced by controlling the inverter, appropriate power can be supplied to a power receiving device that does not require as much power as the object to be heated. The power receiving device can convert the high frequency power received by the power receiving coil into DC power by an electric circuit such as a rectifier and a smoothing capacitor, and supply the DC power to a power consuming unit of the power receiving device such as a DC motor.

  However, in general, when power is supplied from a 50 Hz or 60 Hz commercial AC power source to an electric device having a smoothing capacitor, a commercial AC is required unless a power factor correction means (PFC means: Power Factor Correction) is provided at the input end of the electric device. It is known that the current input from the power source to the electrical equipment is distorted and the power factor is reduced. When an electrical device with a low power factor is connected to a commercial AC power source, other electrical devices connected to the commercial AC power source and the commercial AC power source itself are adversely affected. The same applies to the case where non-contact power feeding is performed to a power receiving device including a power receiving coil. In the conventional induction heating cooker with a non-contact power feeding function described in Patent Document 1, the power receiving device having a smoothing capacitor is not When contact power feeding is performed, there is a problem that the current input from the commercial AC power source to the induction heating cooker is distorted and has a low power factor.

  The present invention has been made to solve the above-described problems, and it achieves a high power factor both when induction heating is performed on an object to be heated and when contactless power feeding is performed on a power receiving device. It aims at obtaining the induction heating cooking appliance with a contact electric power feeding function.

  An induction heating cooker with a non-contact power feeding function according to the present invention includes a top plate on which a load is placed, a heating power supply coil disposed below the top plate, and a commercial AC power supply having a voltage magnitude periodically. A rectifying circuit that rectifies the pulsating DC voltage that fluctuates, a power factor improvement circuit that converts the pulsating DC voltage rectified by the rectifying circuit into a steady DC voltage having a constant voltage, and a high-frequency current in the heating power supply coil. And an inverter circuit that selectively supplies a pulsating DC voltage or a steady DC voltage to the inverter circuit in accordance with a load placed on the top plate. To do.

  According to the present invention, according to the load placed on the top plate, by selectively applying a pulsating DC voltage or a steady DC voltage to the inverter circuit, the object to be heated is efficiently induction-heated, An induction heating cooker with a non-contact power feeding function capable of non-contact power feeding to a power receiving device at a high power factor can be realized.

It is a perspective view which shows the external appearance of the induction heating cooking appliance with a non-contact electric power feeding function which concerns on Embodiment 1 of this invention. It is a block diagram which shows the main circuit structures of the induction heating cooking appliance with a non-contact electric power feeding function which concerns on Embodiment 1. FIG. It is a perspective view which shows the schematic form of the coil used for the induction heating cooking appliance with a non-contact electric power feeding function which concerns on Embodiment 1. FIG. 1 is a circuit diagram of an induction heating cooker with a non-contact power feeding function according to Embodiment 1. FIG. (A) shows the voltage waveform of the external power supply, (b) shows the voltage waveform of the pulsating DC voltage of the rectifier circuit, and (c) shows the voltage waveform at both ends of the coil when the pulsating DC voltage is applied to the inverter. (D) shows the voltage waveform of the steady DC voltage of the power factor correction circuit, and (e) is a graph showing the voltage waveform at both ends of the coil when the steady DC voltage is applied to the inverter. It is a top view which shows an example of the operation part of the induction heating cooking appliance with a non-contact electric power feeding function. It is a circuit diagram which shows the circuit which discriminate | determines load by operation of an operation part. It is a block diagram which shows the main circuit structures of the induction heating cooking appliance with a non-contact electric power feeding function which concerns on Embodiment 2. FIG. It is a circuit of the induction heating cooking appliance with a non-contact electric power feeding function which concerns on Embodiment 2, Comprising: It is a circuit diagram containing the power factor improvement circuit using a pressure | voltage rise chopper. FIG. 10 is a circuit diagram similar to FIG. 9 including a power factor correction circuit using a step-down chopper. It is a block diagram which shows the main circuit structures of the induction heating cooking appliance with a non-contact electric power feeding function which concerns on Embodiment 3. FIG. It is a top view which shows an example of the operation part of the induction heating cooking appliance with a non-contact electric power feeding function which concerns on Embodiment 3, and a display part. It is a block diagram which shows the main circuit structures of the induction heating cooking appliance with a non-contact electric power feeding function which concerns on Embodiment 4. It is a top view which shows an example of the operation part of the induction heating cooking appliance with a non-contact electric power feeding function which concerns on Embodiment 4, and a display part. It is a schematic block diagram of the induction heating cooking appliance with a non-contact electric power feeding function which concerns on Embodiment 4. It is a schematic block diagram of the induction heating cooking appliance with a non-contact electric power feeding function which concerns on Embodiment 4. It is a circuit diagram which shows some power receiving circuits of the power receiving apparatus which is contactlessly fed by the induction heating cooker 1 with a contactless power feeding function according to the present invention. It is a circuit diagram of the induction heating cooking appliance with a load discrimination | determination function which concerns on Embodiment 5, and a receiving device. 6 is a graph illustrating frequency characteristics of resistance components at both ends of a coil obtained when different types of loads are placed. It is a perspective view which shows the principal part of the induction heating cooking appliance 1 with a non-contact electric power feeding function which discriminate | determines load using RF tag.

Embodiment 1 FIG.
FIG. 1 is a perspective view showing an external appearance of an induction heating cooker with a non-contact power feeding function according to Embodiment 1 of the present invention. In FIG. 1, an induction heating cooker 1 with a non-contact power feeding function is formed of an insulating material such as crystallized glass, ceramic, or resin on an upper surface of a box-shaped housing 2 formed of metal such as a steel plate or resin. A top plate 3 is provided. On the top plate 3, the placement areas 4 a, 4 b, 4 c for placing a heated object such as a pot heated by induction or a power receiving device to be contactlessly fed are visually recognized from above by the user. It is defined by printing or the like. In the present application, these placement areas are also called heating units or power supply units, and the number of placement areas arranged on the top plate 3 is also called the number of units. Although the induction heating cooker 1 with a non-contact electric power feeding function of FIG. 1 demonstrates what has three mounting areas, ie, the number of units is three, in this embodiment, the number of units is not restricted to three. There may be 1 or 2 or 4 or more.

  Below the top plate 3 (on the back side), coils 13a, 13b, and 13c described later are provided corresponding to the placement areas 4a, 4b, and 4c. An operation part 5 for a user to operate is provided in front of the upper surface of the induction heating cooker 1 with a non-contact power feeding function, and the operation part 5 is for operating the respective placement areas 4a, 4b, 4c. Individual operation units 5a, 5b, and 5c are provided.

  The operation units 5a, 5b, and 5c are provided with electrostatic sensors at positions below the corresponding top plate 3 to detect changes in capacitance when the user touches the operation unit 5 and use them. An electric signal indicating an operation input by a person may be output. In addition, operation part 5a, 5b, 5c is an electrostatic capacitance type similarly to the upper surface of the induction heating cooking appliance 1 with a non-contact electric power feeding function as a thing separate from insulators, such as crystallized glass which comprises the top plate 3. A sensor may be configured.

  Moreover, the display part 6 is provided in the top plate 3, For example, you may comprise using the liquid crystal display arrange | positioned under the top plate 3. FIG. The display unit 6 provides the user with information such as the operating state of the induction heating cooker 1 with a non-contact power feeding function and alerting the user based on the operating state.

  Further, a main power switch 7 is provided in front of the induction heating cooker 1 with a non-contact power feeding function, and the user sets the main power switch 7 to the “ON” state, so that the induction heating with the non-contact power feeding function is performed. The cooker 1 can be operated. When the main power switch 7 is in the “off” state, operations such as induction heating and / or non-contact power feeding cannot be performed even if the user operates the operation unit 5.

  The induction heating cooker 1 with a non-contact power feeding function shown in FIG. 1 has a grill portion 8 provided with an opening / closing door in front of it, and can perform grilled fish cooking inside the opening / closing door. However, the induction heating cooker 1 with a non-contact power feeding function does not necessarily need to include the grill portion 8.

  Further, the induction heating cooker 1 with a non-contact power feeding function has a power supply (“power supply amount” or simply “fire” output to an object to be heated or a power receiving device placed in the placement area 4a, 4b, 4c in front of it. (Also referred to as “adjustment”) may be provided with rotary dial operation units 9 a, 9 b, 9 c and a dial operation unit 9 d for adjusting the heating of the grill unit 8. However, the dial operation units 9a to 9d are optional and may not be provided.

  Further, the top plate 3 is provided with light emitting rings 10a, 10b, and 10c that emit light in a ring shape along the outer edges of the placement areas 4a, 4b, and 4c. The user can visually recognize the state of the load. The light emitting rings 10a, 10b, and 10c are ring-shaped light guides formed of a high light guide material such as acrylic resin along the outer circumferences (or outer edges) of the coils 13a, 13b, and 13c disposed below the top plate 3. By arranging light emitting diodes that emit light in multiple colors or light emitting diodes with different emission colors in the light incident part of the light guide, light is emitted in various colors based on the state of the mounted load Can be made.

  That is, in the induction heating device with a non-contact power feeding function, the magnitude of the power supplied to the coil 13 and the operation unit 5 by the user in the case of subjecting the object to be heated to induction heating and the case of performing non-contact power feeding to the power receiving device Since the operation of is different, by making the user visually recognize that the induction heating cooker 1 with the non-contact power feeding function correctly recognizes the load placed on the top plate 3, the user's proper operation can be performed. Can help. For example, when the object to be heated is placed on the top plate 3, the light emitting rings 10a, 10b, and 10c may emit red light, and when the power receiving device is placed, light may be emitted blue or green. .

  In this way, the light emitting rings 10a, 10b, and 10c emit light in a warm color such as red that is reminiscent of fire when the object to be heated is inductively heated, and warm colors such as red that are not reminiscent of fire when the power receiving device is contactlessly powered. By emitting light with colors other than those of the system, it is possible to make it easy for the user to communicate intuitively. Furthermore, by using the three primary colors of red, green, and blue light for the light emitting diode, the light emitting rings 10a, 10b, and 10c can be made to emit light in all colors, so there are many types of objects to be mounted. Even if it exists, the light emission rings 10a, 10b, and 10c can be made to emit light with the color corresponding to each, and a user's operativity can be improved.

  Further, a translucent window is formed in the vicinity of the center of the placement areas 4a, 4b, and 4c, and optical sensors 11a, 11b, and 11c are provided below the top plate 3 corresponding to the windows. The optical sensors 11a, 11b, and 11c measure the temperature at the bottom of the heated object by detecting infrared rays emitted from the bottom of the heated object when induction heating the heated object such as a pot. As a function other than the above, external light from a translucent window is detected, and when an object to be heated or a power receiving device is placed on the placement areas 4a, 4b, 4c, the outside light is blocked, You may comprise so that it may detect whether a to-be-heated object or a receiving device is mounted in mounting area 4a, 4b, 4c using the fall of a detection level.

  In addition, an exhaust heat unit 12 for exhausting heat generated inside the induction heating cooker 1 with the non-contact power feeding function is provided. In FIG. 1, the exhaust heat unit 12 is provided on the upper surface of the induction heating cooker 1 with a non-contact power feeding function, but may be provided on the back surface, the side surface, or the lower surface. However, when the exhaust heat unit 12 is disposed in front of or in front of the induction heating cooker 1, it is not desirable because the user receives a warm air and feels uncomfortable.

  FIG. 2 is a block diagram illustrating a main circuit configuration of the induction heating cooker 1 with a non-contact power feeding function according to the first embodiment. The coils 13a, 13b, and 13c are arranged at positions corresponding to the placement areas 4a, 4b, and 4c below the top plate 3. Each coil 13a, 13b, 13c may have the same structure as a coil used in a general induction heating cooker. Specifically, a so-called litz wire made of a plurality of coated copper wires having a diameter of about 0.05 to 0.3 mm, which is a twisted wire, can be formed by spirally winding a plurality of turns, for example, 10 to 20 turns. The shape of each coil 13 is not limited to this, and may have any shape as long as a high-frequency magnetic field is formed in the upper region of the top plate 3 when a high-frequency current is supplied to the coil 13. . For example, instead of forming a coil 13 by winding a conducting wire such as a litz wire a plurality of times, the coil may be formed using a spiral copper pattern on a printed board or the like.

  The coil 13 may have a form other than the above, for example, a form as shown in FIG. The coil 13 shown in FIG. 3 is formed by cutting and bending a metal plate such as a copper plate or an aluminum plate to constitute an electrical closed circuit including a coil portion of approximately one turn. The coil 13 includes a coil portion facing the placement area 4, that is, a heating unit 101, and a power feeding unit 102 that is electrically connected to the heating unit 101 and arranged away from the placement area 4. The coil portion 101 does not inductively heat the power receiving device when performing non-contact power feeding, but is referred to as a heating unit in the present application for convenience. In FIG. 3, the portion that realizes the function of the coil 13 that forms the high-frequency magnetic field is the heating unit 101, and thus the heating unit 101 may be expressed equivalently to the coil 13.

  As shown in FIG. 3, a magnetic body 103 such as a ferrite core is provided so as to surround the power feeding section 102 at one end thereof, that is, to be interlinked, and a power feeding formed by a conducting wire such as a litz wire at the other end. The coil 104 is wound a plurality of turns.

  The feeding coil 104 is connected to the inverter 14 and is supplied with a high-frequency current. The feeding coil 104 generates a high-frequency magnetic flux that passes through the magnetic body 103 when a high-frequency current is supplied from the inverter 14. When the high-frequency magnetic flux is interlinked at the power supply unit 102 of the coil 13, a high-frequency current flows through the coil 13, that is, an electrical closed circuit including the power supply unit 102 and the heating unit 101. Since the power supply coil 104 is wound around the magnetic body 103 for a plurality of turns, the high-frequency current flowing through the coil 13 is extremely large. The magnetic field generated by the high-frequency current induction-heats the object to be heated placed in the placement area 4 or supplies power to the power receiving device in a non-contact manner.

  In order to reduce the magnetic resistance in the radial direction of the heating unit 101 and efficiently perform induction heating or non-contact power feeding by a magnetic field generated by a high-frequency current, another magnetic body 105 is disposed below the heating unit 101. It is preferable. However, the magnetic body 105 for reducing the magnetic resistance of the heating unit 101 is not essential and may be made of ferrite.

  The coil 13 may also be referred to as a “heating coil” for induction heating of an object to be heated, and a “power transmission coil”, “power feeding coil”, “heating / power feeding coil” for performing non-contact power feeding to a power receiving device. Or “primary coil”.

  Referring to FIG. 2 again, the coils 13a, 13b, and 13c are connected to inverters 14a, 14b, and 14c that output a high-frequency current. Power factor correction circuits (PFC circuits) 15a, 15b, and 15c are connected to input terminals of the inverters 14a, 14b, and 14c, respectively, and switches 16a, 16b, and 16c, which are selection means of the PFC circuit 15, are connected. ing. The input ends of the switches 16a, 16b, and 16c are connected to the output end of a single rectifier circuit 17. An input filter 18 for removing high-frequency noise is connected to the input terminal of the rectifier circuit 17, and the input filter 18 is connected to an external commercial AC power source 19 via an inlet plug 19 a and the like. Electric power is supplied to the induction heating cooker 1 with a non-contact power feeding function of the present invention. The commercial AC power supply 19 does not constitute the induction heating cooker 1 with a non-contact power feeding function of the present invention.

  The output end of the input filter 18 is connected to a grill heater 37 provided in the grill portion 8, a relay for controlling the heating of the grill heater 37, and a heater switch 38 such as a semiconductor switching element. When the heater switch 38 is turned on, the grill heater 37 supplied with AC power generates heat and heats the inside of the grill portion 8.

  The control circuit 20 is connected to the output terminal of the rectifier circuit 17, and the 50 Hz or 60 Hz AC voltage input by the rectifier circuit 17 is full-wave rectified and supplied to the control circuit 20 to operate the control circuit 20. Power supply. The control circuit 20 usually includes an arithmetic unit 33 (FIG. 18) such as a microcomputer and a drive circuit for driving the semiconductor switching elements constituting the inverters 14a, 14b, 14c and the power factor correction circuits 15a, 15b, 15c. Have. The control circuit 20 also converts a power output from the rectifier circuit 17 into a power supply voltage for a microcomputer such as 5 V or 3.3 V, and a power converter that converts the power output voltage into a power supply voltage for a 15 V drive circuit. Have various functions.

  The object to be heated 23 and the power receiving devices 24b and 24c are placed on the top plate 3 of the induction heating cooker 1 with the non-contact power feeding function configured as described above. The power receiving devices 24b and 24c have power receiving coils 25b and 25c for receiving power by being combined with the magnetic field generated by the coils 13b and 13c.

  FIG. 4 is a circuit diagram illustrating an exemplary circuit configuration of the induction heating cooker 1 with a non-contact power feeding function according to the first embodiment. FIG. 4 shows the case where the number of units is 1 (when the number of coils 13 is single). However, when the number of units is 3 as shown in FIG. 2, a circuit subsequent to the rectifier circuit 17 shown in FIG. Connect three in parallel. The power factor correction circuit 15 can be configured as a boost chopper circuit including a reactor L, a semiconductor switching element Q3 such as an IGBT or a MOSFET, and a diode D. The inverter 14 can be configured by a half bridge circuit in which semiconductor switching elements Q1, Q2 such as IGBT or MOSFET are connected in series and an intermediate node thereof is used as an output terminal.

  A capacitor C1 is connected to the input terminal of the inverter. Since the capacitor C1 is composed of a film capacitor or a ceramic capacitor having a small capacitance of about 10 μF, a smoothing function for a low frequency of 50 Hz or 60 Hz of the external power source 19 is used. There is no problem that the input current of the induction heating cooker 1 with the non-contact function is greatly distorted by the capacitor C1 and the power factor is reduced.

  A capacitor C2 having good high frequency characteristics such as a film capacitor or a ceramic capacitor is connected to an intermediate node of the semiconductor switching elements Q1 and Q2, a capacitor C2 and a coil 13 are connected in series, and the other end of the coil 13 is a low voltage of the inverter 14. Connected to the side.

  Although FIG. 4 shows that the power factor correction circuit 15 is realized by using a boost chopper circuit, the present invention is not limited to this, and may be realized by using a step-down chopper circuit. You may implement | achieve using the rate improvement circuit 15. FIG. That is, as the power factor correction circuit 15, power factor improvement circuits using various circuit methods are widely known in addition to the boost chopper circuit shown in FIG. 4, and the power factor improvement circuits based on these known circuit methods are replaced with boost chopper circuits. Can be used.

  The inverter 14 is not limited to a half-bridge circuit, and may be a full-bridge circuit or a single-stone resonance type circuit. That is, the inverter 14 may use any circuit as long as it converts a DC voltage (including a DC voltage whose voltage magnitude varies periodically) into a high-frequency voltage and outputs it. In the present application, a DC voltage whose voltage varies periodically is also referred to as a “pulsating DC voltage”.

  The switch 16 can selectively switch whether the direct-current voltage output from the rectifier circuit 17 is directly input to the inverter 14 or input to the inverter 14 via the power factor correction circuit 15. Switch. The switch 16 is switched by a selection signal from a driver circuit 22 provided in the control circuit 20. The driver circuit 22 also outputs a control signal for controlling switching of the semiconductor switching element Q3 of the power factor correction circuit 15 and the semiconductor switching elements Q1 and Q2 of the inverter circuit 14.

  The driver circuit 22 is connected to a load determination unit 21 provided in the control circuit 20, and switches the switch 16 in response to a determination signal from the load determination unit 21. The load determination means 21 may be constituted by, for example, a microcomputer operation program (software) constituting the control circuit 20 or hardware such as an electronic circuit. For example, the operation unit 5 includes a button A for the user to select induction heating and a button B for selecting non-contact power feeding. The button A is connected to the input terminal A of the microcomputer, and the button B is the microcomputer. When the user presses either the button A or the button B, the load determination means 21 is a signal that causes the microcomputer program to be input to the input terminal A and the input terminal B. Are compared to determine that the button A or button B has been pressed, and the determination signal is output.

  The induction heating cooker 1 with a non-contact power feeding function is connected to an external AC power source 19 via an inlet plug 19a and supplied with electric power.

  Next, the operation will be described. Fig.5 (a)-FIG.5 (e) are the graphs which show schematically the voltage waveform in the output terminal of some components of the induction heating cooking appliance 1 with a non-contact electric power feeding function of this invention. The voltage waveforms shown in FIGS. 5A to 5E will be described with reference to the circuit diagram of FIG.

  FIG. 5A shows a voltage waveform of the external power supply 19, which is a voltage waveform input to the rectifier circuit 17 via the inlet plug 19 a and the input filter 18. FIG. 5B is an output waveform of the pulsating DC voltage of the rectifier circuit 17. The voltage waveform shown in FIG. 5B is input to the inverter 14 when the load placed on the placement area 4 of the top plate 3 and the load discriminating means 21 judge the object to be heated and the load to be heated. It is also a voltage waveform. When the load determination means 21 determines that the load is an object to be heated, the output voltage of the rectifier circuit 17 is directly input to the inverter 14 without going through the power factor correction circuit 15 as shown in FIG. The switch 16 is switched as follows.

  FIG. 5C shows voltage waveforms at both ends of the coil 13 when the load determining means 21 determines that the load is an object to be heated. The inverter 14 switches the pulsating DC voltage of FIG. 5B input thereto at a frequency of 20 to 100 kHz to generate a high frequency voltage waveform. Since this high-frequency voltage waveform is applied to the series connection of the capacitor C2 and the coil 13, the DC component is removed by the capacitor C2, and the amplitude of the voltage waveform is shown by a broken line in FIG. A high frequency alternating voltage that varies along the line is applied. Similarly to the high-frequency voltage waveform applied to both ends of the coil 13, the current waveform flowing in the coil 13 is a waveform whose amplitude changes along the envelope indicated by the broken line in FIG. As described above, when the load determining means 21 determines that the load is an object to be heated, the power supplied from the external power source 19 passes through the reactor L of the power factor correction circuit 15, the diode D, and the semiconductor switching element Q3. Without being input directly to the inverter 14. Therefore, the object to be heated can be induction-heated with high efficiency without causing loss due to the power factor correction circuit 15.

  Next, the case where the load determination unit 21 determines that the load is a power receiving device that is contactlessly supplied with power will be described. When determining that the load is a power receiving device, the load determination unit 21 switches the switch 16 so that the output terminal of the rectifier circuit 17 is connected to the input terminal of the power factor correction circuit 15, unlike FIG. 4.

  The power factor correction circuit 15 receives the full-wave rectified voltage waveform shown in FIG. The power factor correction circuit 15 outputs a substantially constant DC voltage Vdc so as to reduce distortion of the current waveform input from the external power source 19 and maintain the power factor high. That is, FIG. 5D shows an output voltage waveform of the power factor correction circuit 15, which is also a voltage waveform input to the inverter 14, and is also referred to as “steady DC voltage Vdc” in the present application. The DC voltage input to the inverter 14 is switched at a frequency of 20 kHz to 100 kHz and input to the capacitor C2 and the coil 13 connected in series. Therefore, a high-frequency AC voltage with a constant voltage waveform envelope is applied to both ends of the coil 13 as shown in FIG. At this time, a high-frequency current flows through the coil 13 to generate a high-frequency magnetic field, and the power receiving coil 25 of the power receiving device 24 placed in the placement area 4 of the top plate 3 receives the power by coupling with the high-frequency magnetic field. Even when the power receiving device has a smoothing capacitor, the high-frequency current flowing through the coil 13 (and the high-frequency magnetic field generated by the coil 13) is supplied via the power factor correction circuit 15, The distortion of the current input from the external power source 19 to the induction heating cooker 1 with the non-contact power feeding function is reduced, and a high power factor can be obtained.

  As described above, in the induction heating cooker 1 with the non-contact power feeding function of the present invention, the load placed on the top plate 3 by the load determination means 21 does not need to essentially improve the power factor. It is determined whether the device is an object or a power receiving device that needs to be improved in power factor. When the load determination means 21 determines that it is necessary to improve the power factor, the load determination means 21 selects the switch 16 to use the power factor improvement circuit 15 so that the load is an object to be heated by induction heating. Regardless of whether the power receiving device is a non-contact power feeding device, the distortion of the input current waveform can be suppressed as much as possible to obtain a high power factor.

  In general, the power consumption of a power receiving device such as a juicer mixer that is contactlessly fed is smaller than the power consumption required for induction heating of an object to be heated such as a pan. No conventional induction heating cooker with a non-contact power feeding function has been proposed that includes a power factor correction circuit so that current input from a commercial AC power source to the induction heating cooker is not distorted. According to the present invention, the load determining means 21 for determining whether the object to be heated is inductively heated and the case where the power receiving device is contactlessly supplied with power is provided, and the necessity of using the power factor correction circuit 15 is selected. In the case of non-contact power feeding to the power receiving device, the power factor improving circuit 15 is used to prevent distortion of the current input from the commercial AC power source to the induction heating cooker and achieve a high power factor, When induction heating is performed, the loss due to the power factor correction circuit 15 can be avoided and the object to be heated can be induction heated with high efficiency.

  As described above, when an object to be heated is induction-heated, a smoothing capacitor is not required, so the AC voltage input from the commercial AC power supply is full-wave rectified, converted into a pulsating DC voltage, and supplied to the inverter. In general, the inverter converts the high frequency alternating current power into a pulsating current and inputs it to a coil to inductively heat the object to be heated. For induction heating of an object to be heated, for example, a maximum of 3 kW of electric power is required, and when there are a plurality of heating units, a larger electric power is required for the entire induction heating cooker (in Japan, the entire induction heating cooker is required by the Fire Service Act). Is limited to 5.8 kW). Therefore, an induction heating cooker that performs only induction heating essentially does not need to improve power factor, and a power factor improvement circuit that can handle large power consumption has a complicated internal structure and occupies a large volume. In order to expand (become large), it is common not to provide a power factor correction circuit. Nonetheless, in cases where induction heating or non-contact power supply is performed by providing a power factor correction circuit for non-contact power supply of a power receiving device that requires relatively less power than induction heating of an object to be heated. Always doing power factor improvement is inefficient in several ways.

  First, the circuit elements constituting the power factor correction circuit must use the one corresponding to the maximum power input to the power factor correction circuit, and the input terminal of the induction heating cooker 1 with the non-contact power feeding function If a single power factor correction circuit is installed in the power factor correction circuit, it is necessary to use circuit elements such as reactors, diodes, and semiconductor switching elements of the power factor correction circuit with large rated capacity. The element becomes large, the internal structure of the power factor correction circuit becomes complicated, and the manufacturing cost increases.

  Secondly, when the object to be heated is induction-heated, the power switching circuit of the power factor correction circuit is operated even though it is not necessary to improve the power factor. Occurs, and the power efficiency of the induction heating device decreases. Thus, in a conventional induction heating cooker with a non-contact power feeding function, when a power factor improving circuit that always operates is provided, there is a problem that the induction heating device becomes large and costs increase. If not provided, when non-contact power feeding is performed to a power receiving device having a smoothing capacitor, there is a problem that an input current to the induction heating device is distorted and a power factor is lowered.

  On the other hand, the induction heating cooker 1 with the non-contact power feeding function according to the present invention determines the load on which the load determining means 21 is placed as described above, and the load does not require power factor improvement. It discriminate | determines whether it is the to-be-heated object to be heated, or the receiving device of non-contact electric power feeding which needs a power factor improvement, and switches a switch according to a discrimination | determination result. The power consumption of the power receiving device is generally smaller than the power consumption required for induction heating of the object to be heated. Therefore, the induction heating cooker 1 with the non-contact power feeding function according to the present invention uses the power factor improvement circuit 15 interposed between the rectifier circuit and the inverter circuit when performing non-contact power feeding to the power receiving device. Although improvement is made, since the power consumption of a general power receiving device is relatively small, the circuit element of the power factor correction circuit 15 can be made to have a small rated capacity. Therefore, according to the present embodiment, it is possible to realize the induction heating cooker 1 with the non-contact power feeding function that is small and inexpensive in the power factor correction circuit 15.

  Further, since the switches 16a, 16b, 16c and the power factor correction circuits 15a, 15b, 15c are provided for each heating unit corresponding to the placement area of the induction heating cooker 1 with the non-contact power feeding function, for example, a specific heating unit Then, it is possible to perform induction heating of the object to be heated without power factor improvement, and non-contact power feeding to the power receiving device with power factor improvement can be performed with another heating unit, which can improve the convenience for the user. .

  In addition, even a power receiving device that is contactlessly supplied with power has a smoothing capacitor, and therefore there is a power receiving device that does not require power factor improvement. When the power receiving device to be contactlessly fed is a device that includes a heater inside and cooks food by heating the heater, such as an oven toaster and a fish roaster, most of the electric power is a resistive load Consumed by the heater. Performing power factor improvement for a device having a heater with high power consumption in this way is disadvantageous in realizing a small and inexpensive power factor improvement circuit 15. In this embodiment, the load determination means 21 determines that the user has operated the button A for selecting induction heating or the button B for selecting non-contact power supply, and supplies a determination signal to each heating unit. Therefore, it is possible to avoid contactless power feeding via the power factor correction circuit 15 to a power receiving device that does not need to improve the power factor.

  FIG. 6 is a plan view illustrating an example of the operation unit 5 of the induction heating cooker 1 with a non-contact power feeding function. The operation unit 5 illustrated in FIG. 6 is an example of the operation unit 5 that allows the user to select whether or not the power factor needs to be improved regardless of whether the load is an object to be heated or a power receiving device. The operation unit 5 includes three operation buttons 26a, 26b, and 26c displayed as “IH”, “WPT1”, and “WPT2”. “IH” is an abbreviation for “Induction Heating” and means induction heating. “WPT” is an abbreviation of “Wireless Power Transfer” and indicates non-contact power feeding. Contactless power transfer is sometimes called “Contactless Power Transfer” in English, but in recent years the term “Wireless Power Transfer” is commonly used, and it is also commonly referred to as wireless power transfer in Japanese. It is becoming.

  “WPT1” is a button that is pressed when performing non-contact power supply to a power receiving device that does not require power factor improvement, such as an oven toaster, and “WPT2” is a power reception that requires power factor improvement, such as a juicer mixer. This button is pressed to perform non-contact power supply to the device. The characters displayed on the buttons are not limited to this, and may be displayed in a manner that is easy for the user to understand according to the country in which they are used, and may be characters or designs in other languages.

  FIG. 7 is a circuit diagram showing a circuit for determining a load by operating the operation unit 5. In addition, this circuit diagram is an example and is not limited to this. The operation buttons 26a, 26b, and 26c arranged on the operation unit 5 are configured by push switches that are turned on when pressed. This circuit is constituted by a part of the microcomputer 24, and is based on whether or not the operation button 5 has been pressed and a signal inputted to the input terminals 21a, 21b, and 21c of the microcomputer 24 arranged in the control circuit 20. Determine by program. In other words, the microcomputer program is the load determination means 21.

  When the user desires non-contact power supply to a power receiving device that does not require power factor improvement, the user presses the operation button 26b of “WPT1”. Then, the push switch of the operation button 26b is turned on, and the voltage of the input terminal 21b of the microcomputer 24 becomes 0V. On the other hand, since the operation button 26a and the operation button 26b are not pressed, the push switch is in an OFF state, and the voltages of the input terminal 21a and the input terminal 21c of the microcomputer 24 are both 5V. The microcomputer program (load determination means 21) detects the pressed operation buttons by detecting the voltages at the input terminals 21a, 21b, and 21c, and determines what the loaded load is. When it is determined that the load is a power receiving device that does not require power factor improvement, the load determination unit 21 outputs a signal for controlling the switch 16 from the output terminal 21d so as not to use the power factor correction circuit 15.

  As described above, the load determination unit 21 performs induction heating on the object to be heated (IH), non-contact power feeding to a power receiving device that does not require power factor improvement (WPT1), or a power receiving device that requires power factor improvement. Since the power factor correction circuit 15 is used only when power is supplied to a power receiving device that requires relatively small power, it is determined that power is not contacted (WPT2). The power factor correction circuit 15 can be configured to be small and inexpensive by using the element.

Embodiment 2. FIG.
FIG. 8: is a block diagram which shows the main circuit structures of the induction heating cooking appliance 1 with a non-contact electric power feeding function of Embodiment 2 of this invention. In the first embodiment, the switch for selecting whether or not to use the power factor correction circuit 15 is used. However, the induction heating cooker 1 with the non-contact power feeding function according to the second embodiment does not use a switch. Whether or not to use the power factor correction circuit 15 is selected depending on whether or not the semiconductor switching elements constituting the factor improvement circuit 15 are operated. The other detailed configuration of the second embodiment is the same as that of the first embodiment, and thus redundant description is omitted.

  In the induction heating cooker 1 with the non-contact power feeding function shown in FIG. 8 as shown in FIG. 8, the switches 16a, 16b, and 16c do not exist as is apparent from the comparison with the first embodiment shown in FIG. The 17 output terminals are directly connected to the power factor correction circuits 15a, 15b, and 15c corresponding to the placement areas. The control circuit 20 controls the operation / non-operation of the power factor correction circuits 15a, 15b, 15c (semiconductor switching element Q3 constituting the power factor improvement circuit) based on the determination signal from the load determination means 21.

  FIG. 9 is a circuit diagram illustrating an exemplary circuit configuration of the induction heating cooker 1 with a non-contact power feeding function according to the second embodiment, in which a boost chopper is used for the power factor correction circuit 15. FIG. 10 is a circuit diagram when a step-down chopper is used for the power factor correction circuit 15. The power factor correction circuit 15 is not limited to the step-up chopper type in FIG. 9 and the step-down chopper type in FIG. 10, and may have other forms such as a step-up / step-down chopper type. That is, the induction heating cooker 1 with the non-contact power feeding function according to the second embodiment performs the switching operation of the semiconductor switching element Q3 that constitutes the power factor correction circuit 15 (by repeatedly switching the on and off states alternately). A power factor correction circuit having an arbitrary form is provided as long as the power factor is not improved by improving the factor and not switching the semiconductor switching element (on or off). 9 and 10 show the circuit configuration of the induction heating cooker 1 with a non-contact power feeding function having a single heating unit, as in FIG.

  First, the operation of the induction heating cooker 1 with the non-contact power feeding function when the power factor correction circuit 15 is configured by a boost chopper as shown in FIG. 9 will be described. An object to be heated that is induction-heated or a power-receiving device that does not require power factor improvement is placed in the placement area 4, and the load determination unit 21 determines that the load does not need to be improved in power factor. At this time, the driver circuit 22 outputs a determination signal such that the semiconductor switching element Q3 constituting the power factor correction circuit 15 is always in an OFF state based on the determination result. This determination signal is, for example, a voltage such that the gate-emitter voltage is 0V when the semiconductor switching element is an IGBT, and a gate-source voltage is 0V when the semiconductor switching element is a MOSFET. When the semiconductor switching element Q3 is in the OFF state, the full-wave rectified voltage shown in FIG. 5B output from the rectifier circuit 17 is passed through the reactor L and the diode D of the power factor correction circuit 15 to the inverter 14 as it is. Entered. That is, the input voltage waveform of the inverter 14 becomes a pulsating DC voltage waveform as shown in FIG. Thus, as in the first embodiment, the voltage at both ends of the coil 13 and the current flowing through the coil 13 have waveforms as shown in FIG.

  On the other hand, when a power receiving device to which power factor improvement is required is placed in the placement area 4 and the load determination unit 21 determines that the power factor improvement is necessary, the driver circuit 22 determines the determination. Based on the result, a determination signal is output such that the semiconductor switching element Q3 constituting the power factor correction circuit 15 is repeatedly switched between ON and OFF states. This discrimination signal has, for example, a voltage waveform such that when the semiconductor switching element is IGBT, the gate-emitter voltage is on when it is 15 V, and when it is 0 V, it is off. It has a voltage waveform such that it is in an on state when the source voltage is 15V and in an off state when it is 0V. At this time, the power factor correction circuit 15 receives a full-wave rectified voltage waveform as shown in FIG. 5B, but outputs a constant DC voltage waveform having a constant voltage as shown in FIG. 5D. When this steady DC voltage is input to the inverter 14, the voltage at both ends of the coil 13 and the current flowing through the coil 13 have waveforms as shown in FIG.

  As described above, the induction heating cooker 1 with the non-contact power feeding function according to the second embodiment does not use the switch 16 but performs the switching operation of the semiconductor switching element Q3 that constitutes the power factor correction circuit 15 configured by the boost chopper. By controlling this, it is possible to select whether or not to improve the power factor. When power factor correction is not performed, no current flows through the semiconductor switching element Q3 maintained in the off state. Therefore, the semiconductor switching element Q3 constituting the power factor correction circuit 15 has a relatively small rated current and a small size. There is an advantage that an inexpensive semiconductor switching element can be used.

  Next, the operation of the induction heating cooker 1 with the non-contact power feeding function when the power factor correction circuit 15 is configured by a step-down chopper as shown in FIG. 10 will be described. As will be described in detail later, when the power factor correction circuit 15 is configured using a step-down chopper, the point that the semiconductor switching element Q3 is maintained in the ON state when the power factor correction is not performed is different from the case where the step-up chopper is used. Also in the power factor correction circuit 15 configured by a step-down chopper, the semiconductor switching element Q3 is similarly switched.

  A load discriminating means 21 indicates that an object to be heated that is induction-heated or a power receiving device that is contactlessly fed without the need for power factor improvement is placed on the placement area 4 and the load is a load that does not require power factor improvement. Is determined, the driver circuit 22 outputs a determination signal based on the determination result so that the semiconductor switching element Q3 constituting the power factor correction circuit 15 is always turned on. When the semiconductor switching element Q3 is in the ON state, the full-wave rectified voltage shown in FIG. 5B output from the rectifier circuit 17 is passed through the reactor L and the diode D of the power factor correction circuit 15 to the inverter 14 as it is. Entered. That is, the input voltage waveform of the inverter 14 becomes a pulsating DC voltage waveform as shown in FIG.

  At this time, the current output from the rectifier circuit 17 flows through the semiconductor switching element Q3 and the reactor L, but does not flow through the diode D. Since the current when the power factor is not improved is a large current corresponding to the current flowing through the heating coil, the rated current of the semiconductor switching element Q3 must correspond to this large current. That is, the semiconductor switching element Q3 needs to be larger and more expensive than that used in the step-up chopper. However, since the diode D used in the step-down chopper only has a small current when power factor improvement is performed, a diode D having a small rated current can be used, and a small and inexpensive diode D should be used. There is an advantage that you can. In addition, when the power factor is not improved, the semiconductor switching element Q3 is not switched, so that the switching loss of the semiconductor switching element Q3 can be eliminated regardless of the size of the load. There is an advantage that non-contact power feeding that does not require improvement can be performed. The merit regarding the switching loss is the same as that of the step-up chopper.

Embodiment 3 FIG.
FIG. 11 is a block diagram illustrating a main circuit configuration of the induction heating cooker 1 with a non-contact power feeding function according to the third embodiment. The induction heating cooker 1 with the non-contact power feeding function according to the first and second embodiments is provided with the power factor improvement circuit 15 corresponding to each heating unit, and the power factor is improved according to the determination result of the load determination unit 21. Whether or not the circuit 15 is used is controlled, but the induction heating cooker 1 with the non-contact power feeding function according to the third embodiment includes the single power factor correction circuit 15 and the determination result of the load determination unit 21 Accordingly, whether to use the power factor correction circuit 15 is controlled. The other detailed configuration of the third embodiment is the same as that of the first and second embodiments, and thus redundant description is omitted.

  As shown in FIG. 11, the induction heating cooker 1 with a non-contact power feeding function selects a single power factor improvement circuit 15 and whether or not to use the power factor improvement circuit 15 after the rectifier circuit 17. One switch 16 is provided. Whether or not to use the power factor correction circuit 15 is selected using the switch 16 shown in FIG. 11 or, as described in the second embodiment, the semiconductor switching elements constituting the power factor correction circuit 15. You may carry out by on / off control. Moreover, although the induction heating cooking appliance 1 with a non-contact electric power feeding function shown in FIG. 11 has three heating units, the number of units is not restricted to 3, and may be 4 or more, or 2 or less.

  Inverters 14a, 14b, and 14c for supplying high-frequency current to the coils 13a, 13b, and 13c corresponding to the mounting areas 4a, 4b, and 4c are connected to the power factor improving circuit 15 and the subsequent stage of the switch 16, respectively. Since the input terminals of the inverters 14a, 14b, and 14c are connected to nodes having the same potential, the same voltage is input. When the use of the power factor correction circuit 15 is selected by the switch 16 or the like, a constant voltage DC voltage waveform (steady DC voltage) as shown in FIG. 5D is input to each of the inverters 14a, 14b, and 14c. When it is selected not to use the power factor correction circuit 15 by the switch 16 or the like, a full-wave rectified pulsating DC voltage as shown in FIG. 5B is input to the inverters 14a, 14b, and 14c. As shown in FIG. 11, when the switch 16 is selected to be connected to the power factor correction circuit 15, a constant DC voltage is input to each of the inverters 14a, 14b, and 14c. As shown in FIG. 11, when no load is placed on the placement area 4a and the power receiving devices 24b and 24c are placed on the placement areas 4b and 4c, the inverter 14a does not perform a switching operation. The high frequency current does not flow through 13a, but the inverter 14b and the inverter 14c perform a switching operation, the high frequency current of 20 kHz to 100 kHz flows through the coil 13b and the coil 13c, the high frequency magnetic field is generated, and the power receiving devices 24b and 24c have. Power is received by the power receiving coils 25b and 25c and non-contact power feeding is performed.

  FIG. 12 is a plan view showing an example of the operation unit 5 and the display unit 6 of the induction heating cooker 1 with a non-contact power feeding function according to Embodiment 3 of the present invention. In addition to the operation units 5a, 5b, and 5c corresponding to the placement areas 4a, 4b, and 4c, the operation unit 5 is provided with a button for performing induction heating and a button for performing non-contact power feeding. In FIG. 12, the button labeled “IH” is a button for performing induction heating, and the button labeled “WPT” is a button for performing non-contact power feeding.

  When the user sets the main power switch 7 to “ON”, a message for prompting the user to select whether to use the induction heating cooker 1 with the non-contact power feeding function for induction heating or non-contact power feeding is displayed on the display unit 6. Is displayed. At this time, the operation unit 5 can be operated only by the “IH” button and the “WPT” button, and the operation units 5a, 5b, and 5c are configured not to accept the operation. For example, when “Please press the IH button or WPT button” is displayed on the display unit 6 and the user accidentally presses one of the buttons on the operation unit 5a, 5b, or 5c, “the operation is invalid”. Is displayed. When the user presses the “IH” button or the “WPT” button, the load discriminating means 21 provided in the control circuit 20 is a heated object that performs induction heating or a power receiving device that performs non-contact power supply. And the switch 16 is switched based on the determination result to select whether or not to use the power factor correction circuit 15. As described above, the “object to be heated that performs induction heating” of the present application may include a “power receiving device that performs non-contact power supply” in which a load such as an oven toaster does not require power factor improvement.

  Further, although the user has selected the “WPT” button, it is assumed that the load actually placed in the placement area 4 is not a power receiving device but an object to be heated by induction heating. At this time, since the “WPT” button has been pressed, the load determination unit 21 determines that the load is a power receiving device that performs power factor improvement, and switches the switch 16 to use the power factor correction circuit 15. That is, the load discriminated by the load discriminating means 21 in the present embodiment refers to the load regardless of whether or not the load actually placed in the placement area 4 requires power factor improvement. Depending on the required induction heating (“IH” button) or non-contact power supply (“WPT” button) for the load, the actual load may differ from the actual load.

  More specifically, the “WPT” button for allowing the user to perform non-contact power feeding even when the object to be heated that is to be induction-heated is placed in the placement area 4 and no power factor improvement is required. When is pressed, the load requested by the user is a load that is contactlessly fed and requires power factor improvement, and the load determination unit 21 determines the load according to the user's request. However, when an object to be heated is placed in the placement area 4, since non-contact power feeding cannot be performed, the induction heating cooker 1 with a non-contact power feeding function is actually placed by another means. The load selected by the user may be displayed on the display unit 6 by determining whether the loaded load is an object to be heated or a power receiving device. Further, the result of automatically determining the load may be transmitted to the load determining means 21 and the load determining means 21 may select whether or not to use the power factor correction circuit 15 regardless of the operation of the user. A method for automatically determining the load will be described in another embodiment.

  As shown in FIG. 11, nothing is placed in the placement area 4a, and the induction heating cooking with a non-contact power feeding function when the power receiving devices 24b and 24c are placed in the placement areas 4b and 4c. The operation of the container 1 will be described. First, when the user presses the “WPT” button of the operation unit 5 in FIG. 12, it is determined that the load determination unit 21 uses the power factor correction circuit 15, and the switch 16 is switched to use the power factor improvement circuit 15. Then, the operation units 5b and 5c can be operated. When the user presses the button labeled “START” on the operation unit 5b, non-contact power feeding to the power receiving device 24b is started. When the user presses the button labeled “START” on the operation unit 5c, the power receiving device The non-contact power supply to 24c is started. Then, the user increases the power for non-contact power feeding by pressing the button labeled “+” on the operation units 5b and 5c, and decreases the power for non-contact power feeding by pressing the button labeled “−”. Can be made. At this time, since the switch 16 is switched to use the power factor correction circuit 15, a DC voltage having a constant voltage as shown in FIG. 5D is output from the power factor correction circuit 15 and input to the inverters 14b and 14c. Is done. Therefore, even when the power receiving devices 24b and 24c have smoothing capacitors, the current input from the external power source 19 is not distorted and a high power factor is obtained.

  In addition, when the load is induction-heated, the switch 16 is switched so as not to use the power factor correction circuit 15 and can be similarly operated by the operation units 5b and 5c. In the case of induction heating, the power factor is not improved. However, since there is no need to improve the power factor, the current input from the external power source 19 is not distorted and a high power factor is obtained.

  When nothing is placed on the placement area 4a, it is desirable that a high-frequency current is not supplied from the inverter 14a to the coil 13a even if the user operates the operation unit 5a. Several methods have been proposed for the induction heating cooker 1 with a non-contact power feeding function to detect whether or not a load is placed on the placement area 4a. For example, as a general induction heating cooker without a non-contact power feeding function is performing, a minute electric power is supplied from the inverter 14a to the coil 13a, and the impedance is measured from the voltage and current of the coil 13a at this time, It may be detected whether or not a load is placed by a change in impedance. Further, as described in the first embodiment, whether or not a load is placed may be detected using the optical sensor 11a. When it is detected that nothing is placed on the placement area 4a by such a method, a microcomputer mounted on the control circuit 20 so that the switching operation of the inverter 14a is not performed even when the operation unit 5a is pushed. You can control with.

  Alternatively, when the “START” button of the operation unit 5a is pressed, the inverter 14a is operated for a short time to pass a high-frequency current through the coil 13a, and the impedance is measured from the voltage and current of the coil 13a at that time. When it is determined that nothing is placed, the operation of the inverter 14a may be stopped. At this time, since nothing is placed on the placement area 4a on the display unit 6, it is desirable to display a message indicating that the supply of the high-frequency current to the coil 13a is stopped because the user can easily use it.

  As described above, the induction heating cooker 1 with the non-contact power feeding function according to the third embodiment of the present invention includes the single power factor improvement circuit 15 and performs all the power factor improvement for the non-contact power feeding. Since the voltage output from the power factor correction circuit 15 is supplied to the inverters 14a, 14b, and 14c corresponding to the heating unit or the power feeding unit, it is possible to simultaneously perform both induction heating and non-contact power feeding using different ports. Can not. However, the power required by the power receiving device that needs to improve the power factor is small. For example, even if contactless power feeding is performed using all three power feeding units, the power factor improving circuit 15 outputs the power. Since the power is small, the power factor correction circuit 15 can be realized in a small size and at a low cost.

  On the other hand, when the power factor improvement circuit 15 is provided in the subsequent stage of the rectifier circuit and the necessity of using the power factor improvement circuit 15 is not selected, the power factor improvement circuit 15 always operates. In this case, for example, when all three heating units are used for induction heating, the power factor correction circuit 15 must be configured to handle very large power (maximum power of 5.8 kW in Japan due to the Fire Service Act). I must. However, when all three power supply units are used for non-contact power supply, the power factor correction circuit 15 does not need to cope with such large power. That is, since the induction heating cooker 1 with the non-contact power feeding function according to the third embodiment of the present invention includes the single power factor correction circuit 15, the power factor correction circuit 15 is necessary for induction heating. Therefore, a circuit element such as a semiconductor switching element having a large rated capacity capable of handling the maximum power is required, and the size is increased and the cost is increased.

Embodiment 4 FIG.
FIG. 13: is a block diagram which shows the main circuit structures of the induction heating cooking appliance 1 with a non-contact electric power feeding function of Embodiment 4 of this invention. In the induction heating cooker 1 with a non-contact power feeding function of the fourth embodiment, at least one unit among the plurality of placement areas (units) on the top plate is used as a heating unit dedicated to induction heating, and other units are used. It is configured as a heating / power feeding unit that supports induction heating and non-contact power feeding. Since the other detailed structure of Embodiment 4 is the same as that of Embodiment 1-3, the overlapping description is abbreviate | omitted.

  In the induction heating cooker 1 with a non-contact power feeding function shown in FIG. 13, the placement areas 4 a and 4 b are configured as a heating unit dedicated to induction heating, and the placement area 4 c is heated corresponding to both induction heating and non-contact power feeding. -It is configured as a power supply unit. In this case, since it is not necessary to improve the power factor for the mounting areas 4a and 4b, the input terminals of the inverters 14a and 14b are directly connected to the output terminal of the rectifier circuit 17. On the other hand, for the mounting area 4c, one end of the switch 16 is connected to the rectifier circuit 17 and the other end is connected in order to perform non-contact power supply that requires induction heating or power factor improvement. The power factor correction circuit 15 or the inverter 14c is selectably connected. Instead of the switch 16, as in the second embodiment, whether to perform power factor correction may be selected by on / off control of the semiconductor switching elements constituting the power factor correction circuit 15.

  FIG. 14 is a plan view showing an example of the operation unit 5 and the display unit 6 of the induction heating cooker 1 with a non-contact power feeding function according to Embodiment 4 of the present invention. In the operation unit 5, only the operation unit 5c corresponding to the placement area 4c is provided with an “IH” button and a “WPT” button. When the user presses the “WPT” button, the load determination unit 21 determines that power factor improvement is necessary, and switches the switch 16 to be connected to the power factor correction circuit 15. When the user presses the “IH” button, the load discriminating means 21 determines that the power factor correction is unnecessary, and the switch 16 is disconnected from the power factor correction circuit 15 and switched to be connected to the inverter 14c. The operation in each case is the same as that shown in the above embodiment.

  Next, a description will be given of a case where at least one of the plurality of placement areas on the top plate is dedicated to induction heating, and the other plurality of placement areas are compatible with both induction heating and non-contact power feeding. To do. 15 and 16, one placement area 4a among the three placement areas is a heating unit dedicated to induction heating, and the other two placement areas 4b and 4c are used for both induction heating and non-contact power feeding. It is a schematic block diagram of the induction heating cooking appliance 1 with a non-contact electric power feeding function comprised as a corresponding heating and electric power feeding unit.

  The induction heating cooker 1 with a non-contact power feeding function shown in FIG. 15 includes individual power factor improvement circuits 15b and 15c corresponding to the placement areas 4b and 4c, and the use of each power factor improvement circuit 15b and 15c is necessary. No can be selected by the switches 16b and 16c. That is, the induction heating cooker 1 with a non-contact power feeding function of FIG. 15 does not include the power factor correction circuit 15a corresponding to the placement area 4a dedicated to induction heating, and is the non-contact shown in the first and second embodiments. It has the same configuration as the induction heating cooker 1 with a power feeding function. Therefore, the placement areas 4b and 4c can be operated in the same manner as described in the first and second embodiments, and the same effect is obtained.

  The induction heating cooker 1 with a non-contact power feeding function shown in FIG. 16 includes a power factor correction circuit 15 and a switch 16 that are common to the placement areas 4b and 4c. 16 is selected. That is, the induction heating cooker 1 with a non-contact power feeding function shown in FIG. 16 is the induction heating cooker 1 with a non-contact power feeding function shown in the third embodiment (FIG. 11) except for the placement area 4a dedicated to induction heating. It has the same configuration as. Therefore, the mounting areas 4b and 4c can be operated in the same manner as described in the third embodiment, and the same effect is obtained.

Embodiment 5. FIG.
The load determination unit 21 according to the first to fourth embodiments inputs a result of the user selecting the type of load by operating the operation unit 5 to the load determination unit 21, and based on the result, the load type In the present embodiment, a case will be described in which the load determination means 21 determines the type of load by another method. Therefore, it replaces with the input method to the load determination means 21 of the induction heating cooking appliance 1 with a non-contact electric power feeding function shown in Embodiment 1-4, and uses the input method to the load determination means 21 of this Embodiment. Can do.

  FIG. 17 is a circuit diagram showing a power receiving circuit of a power receiving device that is contactlessly powered by the induction heating cooker 1 with a contactless power feeding function according to the present invention. A general contactless power receiving circuit is configured as shown in FIGS. 17 (a), 17 (b), and 17 (c). The power reception circuit shown in FIG. 17A does not use a resonance capacitor. The power receiving circuit shown in FIG. 17B has a resonant capacitor 29 connected in parallel with the power receiving coil 25, and the power receiving circuit shown in FIG. 17C is a resonant capacitor 29 connected in series with the power receiving coil 25. Have As described above, the non-contact power supply using the resonance capacitor in the power receiving circuit is called a magnetic resonance method or a magnetic resonance method and may be distinguished from an electromagnetic induction method. When distinguished, the method shown in FIG. 17A is often called an electromagnetic induction method. However, as described above, since these are based on the principle of electromagnetic induction in principle, they are not distinguished in the present application, and are all handled as a magnetic field coupling type non-contact power feeding.

  The power receiving circuit of the power receiving device 24 includes a rectifier circuit 27 formed of a diode bridge or the like, and rectifies high-frequency AC power received by the power receiving coil 25 and inputs the rectified power to the load circuit 28. The rectifier circuit 27 is not limited to a full-wave rectifier circuit formed of a diode bridge, and a half-wave rectifier circuit or a voltage doubler rectifier circuit may be used. The load circuit 28 mainly consumes power in the power receiving device 24, and may be, for example, a motor and its peripheral circuit, or a display monitor and its peripheral circuit. When the power receiving device 24 includes a smoothing capacitor, the load circuit 28 includes a smoothing capacitor.

  FIG. 18 is a circuit diagram showing an exemplary circuit configuration of induction heating cooker 1 with a load determination function and a power receiving device according to Embodiment 5 of the present invention. The circuit shown in FIG. 18 is the same as the circuits shown in FIGS. 4, 9, and 10, except that portions related to load determination are extracted and the other portions are simplified. The inverter input power supply 30 shown in FIG. 18 is a full-wave rectified pulsating DC voltage or a steady DC voltage made constant by the power factor correction circuit 15. That is, the inverter input power supply 30 is a simplified circuit diagram of a stage preceding the input terminal of the inverter 14 in FIGS. 4, 9, and 10. Between the output terminal of the inverter 14 and the coil 13, a coil voltage detector 31 that detects the coil voltage V and a coil current detector 32 that detects the coil current I are provided. The coil voltage detection unit 31 is configured by a resistance voltage dividing circuit or a step-down transformer, and the coil current detection unit 32 is configured by a shunt resistor, a current transformer, or the like.

  On the top plate 3, a power receiving device as shown in FIG. The value of the coil voltage V detected by the coil voltage detector 31 and the value of the coil current I detected by the coil current detector 32 are input to an arithmetic device 33 such as a microcomputer provided in the control circuit 20, and the arithmetic device 33 calculates the impedance or resistance component viewed from both ends of the coil 13 from the value of the coil voltage V and the value of the coil current I. The impedance or resistance component viewed from both ends of the coil 13 does not indicate the impedance or resistance component of the coil 13 itself, but includes the effect of placing a power receiving device or a heated object at a position corresponding to the coil 13. It means impedance or resistance component.

  The impedance is represented by a real part (R) and an imaginary part (jX), and the resistance component is the real part (R) of the impedance. Further, the arithmetic unit 33 issues a command to the driver circuit 22 so as to sweep the frequency of the output voltage of the inverter 14, and based on this command, the driver circuit 22 sets the frequency of the output voltage of the inverter 14 to 1 kHz from 20 kHz to 40 kHz, for example. Sweep (frequency sweep) so as to change in steps. Then, the arithmetic unit 33 measures the impedance or resistance component at both ends of the coil 13 when the frequency of the output voltage of the inverter 14 is swept, and obtains its frequency characteristics. Then, the arithmetic unit 33 discriminates the type of the load by the load discriminating means 21 comprising a program recorded in the arithmetic unit 33 from this frequency characteristic, and selects whether or not the power factor improving circuit 15 is to be used. Furthermore, the determination result of the load determination means 21 determines whether nothing is placed on the placement area 4 and / or whether a foreign object (such as a spoon) that should not be placed is placed.

  FIG. 19 is a graph illustrating frequency characteristics of resistance components at both ends of the coil obtained when different types of loads are placed on the placement area. In FIG. 19, the horizontal axis indicates the frequency f, and the vertical axis indicates the magnitude of the (apparent) resistance component R at both ends of the coil 13. FIG. 19 shows four curves representing different frequency characteristics. The long broken line A shows the frequency characteristic of the resistance component R obtained when the load is an object to be heated that is induction-heated, and shows the feature that the magnitude of the resistance component R increases as the frequency f increases. The short broken line B indicates the frequency characteristic of the resistance component R obtained when the load is a power receiving device having no resonance capacitor as shown in FIG. 17A, and the magnitude of the resistance component R does not depend on the frequency f. It is characteristic that it is constant or decreases with frequency f.

  The solid line C shows the frequency characteristic of the resistance component R obtained when the load is a power receiving device having a resonance capacitor as shown in FIGS. 17B and 17C. It shows that the maximum value is obtained at the resonance frequency determined by the inductance of the power receiving coil 25 and the capacitance of the resonance capacitor. In general, the power receiving device can perform non-contact power feeding with the highest efficiency with a high-frequency current having a resonance frequency at which the resistance component R has a maximum value. Therefore, the inverter 14 is controlled so as to supply a high-frequency current having a frequency that substantially matches the resonance frequency at which the resistance component R has a maximum value.

  An alternate long and short dash line D indicates the frequency characteristic of the resistance component R obtained when the object to be heated that is induction-heated or the power-receiving device that is contactlessly fed is not placed on the placement area 4. The resistance component R is characterized by being relatively small. When the frequency characteristic of the resistance component R as indicated by the alternate long and short dash line D is obtained, the control circuit 20 determines that it is not placed on the placement area 4, that is, has no load, and drives the inverter 14. To stop.

  Thus, by measuring the frequency characteristic of the resistance component R at both ends of the coil 13 by frequency sweeping, the type of load placed in the placement area 4 can be determined. Here, the discrimination method based on the frequency characteristic of the resistance component R is described. However, the frequency characteristic of the reactance component (imaginary part of impedance) or the frequency of the phase difference between the coil voltage and the coil current is not limited to the frequency characteristic of the resistance component R. The type of load may be determined based on the characteristics.

  In the above description regarding the load determination method by the load determination means 21, the inverter input power supply 30 input to the inverter 14 when measuring the frequency characteristic of the resistance component R is not particularly mentioned. The inverter input power source 30 may have a full-wave rectified pulsating DC voltage or a steady DC voltage that is made constant by the power factor correction circuit 15. Naturally, even if the voltage from the inverter input power supply 30 is a pulsating DC voltage or a steady DC voltage, it is possible to measure frequency characteristics such as impedance or resistance components at both ends of the coil 13 by the load determination method. It is. However, when a stable voltage is input from the input power supply 30, the inverter 14 can output a stable high-frequency current and can improve the measurement accuracy of the frequency characteristic of the resistance component R. Since the inverter input power supply 30 includes the power factor improvement circuit 15 that can be selectively used, when measuring the frequency characteristics, the use of the power factor improvement circuit 15 is selected, and a constant DC voltage having a constant voltage is selected. Is preferably input to the inverter 14. When measuring the frequency characteristics, the inverter 14 is controlled so as to output a small high-frequency current, so that the power factor improvement circuit 15 appropriately improves the power factor even if the load is a power receiving device that requires small power. Thus, the frequency characteristic can be measured.

  Next, a series of operations of the induction heating cooker 1 with a non-contact power feeding function according to the present invention will be exemplarily described below. The induction heating cooker 1 with a non-contact power feeding function described here is configured as shown in FIGS. 1 and 2 (Embodiment 1), and has a power factor corresponding to each of the placement areas 4a, 4b, and 4c. It is assumed that improvement circuits 15a, 15b, and 15c are provided.

  First, the user sets the main power switch 7 to “ON” in order to use the induction heating cooker 1 with the non-contact power feeding function. Then, the induction heating cooker 1 with a non-contact power feeding function is activated, the switches 16a, 16b, and 16c are switched to select use of the power factor correction circuits 15a, 15b, and 15c, and the arithmetic unit 33 is as described above. The frequency of the high frequency current output from the inverters 14a, 14b, 14c is swept (frequency sweep), and the frequency characteristics of the (apparent) impedance or resistance component R of each coil 13a, 13b, 13c is measured.

  The load discriminating means 21 is, for example, a power receiving device to which a load placed in the placement area 4a is induction-heated, and a load placed in the placement areas 4b and 4c is a non-contact power feeding device. Determine that there is. At this time, the computing device 33 causes the light emitting ring 10a in the placement area 4a to emit red light, and causes the light emitting rings 10b and 10c in the placement areas 4b and 4c to emit green light, so that the loaded load is correctly identified. This is visually communicated to the user. When the operation unit 5 includes an electrostatic sensor and a liquid crystal display, the display content of the operation unit 5a is switched to one suitable for induction heating, and the display content of the operation units 5b and 5c is suitable for non-contact power feeding. Can be switched.

  The load determination means 21 of the arithmetic unit 33 switches the switch 16a so as to select nonuse of the power factor improvement circuit 15a, and holds the switches 16b, 16c so as to select use of the power factor improvement circuits 15b, 15c. To do.

  The user operates induction heating on the object to be heated using the operation unit 5a, and operates non-contact power supply to the power receiving device using the operation units 5b and 5c. At this time, even if the power receiving device includes a smoothing capacitor, the power receiving device is non-contact powered via the power factor correction circuits 15b and 15c, so the input current of the induction heating cooker 1 with the non-contact power feeding function is A high power factor can be obtained without distortion.

  Further, when the user sets the main power switch 7 to “ON”, no load is placed on all or some of the placement areas 4a, 4b, 4c, and the user then loads the load. May be placed. In this case, when the main power switch 7 is set to “ON”, the load discriminating means 21 measures the frequency characteristics such as the (apparent) impedance or the resistance component R of the coils 13a, 13b, 13c by the above method. Detect no load (no load). The computing device 33 maintains the operation units 5a, 5b, and 5c corresponding to the placement areas 4a, 4b, and 4c in which no load is detected in a standby state, and the user touches the operation unit 5 (the operation unit 5 is operated). To use) and wait. At this time, the arithmetic unit 33 does not cause the light emitting rings 10a, 10b, and 10c corresponding to the placement areas 4a, 4b, and 4c where no load is detected to emit light.

  When the user places a load on any of the placement areas 4a, 4b, and 4c, the optical sensors 11a, 11b, and 11c are shielded from external light incident thereon, and some load (object to be heated or power receiving) It is detected that the device is placed. The load discriminating means 21 of the arithmetic unit 33 discriminates the load by the above-described method and causes the light emitting ring 11 to emit light and switches the display content of the operation unit 5 with respect to the placement area 4 detected that the load is placed. Further, instead of detecting that the load is placed on the placement area 4 using the optical sensor 11, the user touches the operation units 5a, 5b, and 5c corresponding to the placement area 4 on which the load is placed. The load determination method may be performed on the load placed on the placement area 4 to determine the placed load.

Embodiment 6 FIG.
The load discriminating means 21 according to the first to fourth embodiments discriminates the load type based on the result of the user operating the operation unit 5 and selecting the load type. Then, the type of load is determined based on the information input to the RF tag attached to the power receiving device. Since the other detailed structure of Embodiment 6 is the same as that of Embodiment 1-4, the overlapping description is abbreviate | omitted.

  As described above, the load discriminating means 21 according to the sixth embodiment will be described with reference to a method for discriminating the type of load using a radio communication technology such as an RF tag. Here, a case where an RF tag (or RFID tag, Radio Frequency Identifier) is used as wireless communication that can be realized at low cost will be described. However, the available wireless communication method is not limited to this, for example, Wi-Fi or Bluetooth (Registered trademark) or other widely used wireless communication at home may be used. The RF tag is expressed in various terms such as an electronic tag, an IC tag, a wireless tag, and an RFID tag. In this application, the term “RF tag” defined in JIS (Japanese Industrial Standard) is unified. And use.

  FIG. 20 is a perspective view showing a main part of the induction heating cooker 1 with a non-contact power feeding function for determining a load using an RF tag. The coil 13 of the induction heating cooker 1 with a non-contact power feeding function is formed by winding a litz wire in a spiral shape, and a wireless antenna 34 is provided near the center of the coil 13. Although not limited to this, the coil 13 shown in FIG. 19 is wound as two rings (an inner ring and an outer ring) obtained by dividing a litz wire in the radial direction in order to uniformly inductively heat an object to be heated. It is configured. The wireless antenna 34 is connected to a wireless transceiver (reader / writer) 35. The wireless transceiver 35 supplies power to the wireless antenna 34 and processes information received by the wireless antenna 34. The wireless transmitter / receiver 35 is connected to the control circuit 20, and a signal (information) received by the wireless transmitter / receiver 35 is sent to the load determining means 21, and the load determining means 21 determines the type of load. The method for selecting whether or not to use the power factor circuit 15 based on the determination result of the load determination means 21 is the same as that described in the first to fifth embodiments.

  On the other hand, the power receiving device 24 includes an RF tag 36 near the center of the power receiving coil 25. An IC chip (not shown) is embedded in the RF tag, and information about the power receiving device (type of power receiving device (such as a juicer mixer), maximum rated power, resonance frequency, etc.) is recorded in the IC chip.

  When the power receiving device 24 is placed in the placement area 4, the wireless transceiver 35 of the induction heating cooker 1 with a non-contact power feeding function supplies power to the wireless antenna 34. The wireless antenna 34 is formed in a coil shape, and radiates a high-frequency magnetic field or microwave toward the RF tag 36 of the power receiving device 24 when electric power is supplied. The RF tag 36 generates an electromotive force upon receiving a high-frequency magnetic field or microwave, reads information recorded in the IC chip of the RF tag 36, and transmits information to the wireless antenna 34. This information is received by the wireless antenna 34, processed by the wireless transceiver 35, and the result is sent to the load determination means 21. Thereby, the load determination means 21 determines the type of load and selects whether or not to use the power factor correction circuit 15. The subsequent operation is the same as in the above embodiment.

  In general, an object to be heated such as an induction heated pan or a frying pan does not include the RF tag 36. Therefore, when the wireless transmitter / receiver 35 receives no information, the load discriminating means 21 determines the loaded load. It is determined that the object is to be heated, and it can be determined that it is not necessary to use the power factor correction circuit 15. In addition, a power receiving device that does not need to use the power factor circuit 15 records information indicating this in advance in an IC chip in the RF tag 36, so that the load of the wireless transmitter / receiver 35 is the power factor circuit. 15 detects that the use of 15 is not required, and the load determination unit 21 receives the information and determines whether the power factor correction circuit 15 is not used.

  In addition, the power receiving device 24 preferably outputs, via the wireless antenna 34 and the wireless transceiver 35, information related to the resonance frequency at which the resistance component R measured from both ends of the power receiving coil 25 has a maximum value to the arithmetic device 33. At this time, it is preferable that the arithmetic unit 33 controls the inverter 14 so that the corresponding light emitting ring 10 emits blue or green light and supplies a high-frequency current having a frequency that substantially matches the resonance frequency. In this case, as described in the fifth embodiment, it is not necessary to determine the frequency characteristic by sweeping the frequency of the high-frequency current output from the inverter 14, and the load determination unit 21 receives the resonance frequency information from the RF tag 36. The induction heating cooker 1 with a non-contact power feeding function can perform non-contact power feeding to the power receiving device 24 with the highest efficiency with a simpler configuration.

  Furthermore, the power receiving device 24 may be a device that does not include a smoothing capacitor and does not require power factor improvement (for example, a rice cooker or a kettle pot). The power receiving device 24 may include at least one temperature sensor (not shown) that measures the internal temperature and the RF tag 36. For example, a rice cooker is a method of cooking delicious rice, boiled rice for about 10 minutes on medium heat, and then cooked for about 15 on low heat, as traditionally expressed as “starting choro chochu pappa”. Is preferable, but information on how to cook rice suitable for the power receiving device 24 is stored in the IC chip in the RF tag 36, and the arithmetic unit 33 is an inverter based on the stored rice cooking information and the temperature information obtained from the temperature sensor. 14 may be controlled. As a specific example of the other power receiving device 24, a hot water pot for sencha can boil scented tea with a fragrant and delicious taste when hot water kept at about 85 ° C. is used after boiling water once. Information about how to brew tea suitable for the type of tea such as sencha is stored in the IC chip in the RF tag 36, and the arithmetic unit 33 is based on the stored sencha information and the temperature information obtained from the temperature sensor. The inverter 14 may be controlled. The operation unit 5 may be configured so that the user can select the amount of rice and the type of tea. Furthermore, at the time when rice cooking is completed or when the temperature reaches an appropriate temperature, the power receiving device 24 communicates with the arithmetic device 33 via the RF tag 36 and the wireless transceiver 35 and displays the fact on the display unit 6. It is preferable that the user (or an audio device such as a speaker (not shown)) is notified to the user.

  As described above, the power receiving device 24 that can be contactlessly powered by the induction heating cooker 1 with the contactless power feeding function according to the present invention has any electrical appliance placed regardless of the necessity of power factor improvement. It can be operated by placing it in the area 4. The power receiving device 24 can receive power with the highest efficiency by using a high frequency magnetic field having a resonance frequency by using the RF tag 36 (including a memory).

DESCRIPTION OF SYMBOLS 1 ... Induction heating cooker with non-contact electric power feeding function, 2 ... Case, 3 ... Top plate, 4, 4a-4c ... Mounting area, 5, 5a-5c ... Operation part, 6 ... Display part, 7 ... Main power supply Switch, 8 ... Grill part, 9a-9d ... Dial operation part, 10a-10c ... Light emitting ring, 11a-11c ... Optical sensor, 12 ... Heat exhaust part, 13, 13a-13c ... Coil (heating / power supply coil), 14 , 14a-14c ... inverter, 15, 15a-15c ... power factor correction circuit, 16, 16a-16c ... switch, 17 ... rectifier circuit, 18 ... input filter, 19 ... commercial AC power supply, 19a ... inlet plug, 20 ... control Circuit, 21 ... Load discriminating means, 22 ... Driver circuit, 24b, 24c ... Power receiving device, 25b, 25c ... Power receiving coil, 26a-26c ... Operation buttons, 31 ... Coil voltage detecting means, 32 ... Il current detection means, 33 ... arithmetic unit, 34 ... wireless antenna, 35 ... wireless transceiver, 36 ... RF tag, 37 ... grill heater, 38 ... heater switch, 101 ... heating unit, 102 ... power feeding unit, 103 ... magnetic body 104: Feed coil, 105: Magnetic material.

Claims (17)

A top plate on which the load is placed;
A heating and feeding coil disposed below the top plate;
A rectifying circuit for rectifying a commercial AC power supply into a pulsating DC voltage whose voltage periodically varies;
A power factor correction circuit that converts the pulsating DC voltage rectified by the rectifier circuit into a steady DC voltage having a constant voltage magnitude;
An inverter circuit for supplying a high-frequency current to the heating and feeding coil;
Depending on the mounted load to the top plate, a pulsating direct current voltage or a constant DC voltage, and a load determination means for selectively applying to said inverter circuit,
The heating and feeding coil includes first and second heating and feeding coils.
The inverter circuit includes first and second inverter circuits that supply high-frequency current to the first and second heating and feeding coils.
The load discriminating means always applies a pulsating DC voltage from the rectifier circuit to the first inverter circuit, and pulsates according to the load placed on the top plate in the second inverter circuit. An induction heating cooker with a non-contact power feeding function , wherein a DC voltage or a steady DC voltage is selectively applied . The heating and feeding coil is composed of a plurality of heating and feeding coils arranged below different loads,
The induction heating cooker with a non-contact power feeding function according to claim 1, wherein the same number of inverter circuits and power factor correction circuits are provided corresponding to each of the heating power feeding coils. The heating and feeding coil is composed of a plurality of heating and feeding coils arranged below different loads,
The same number of inverter circuits are provided corresponding to each of the heating and feeding coils,
The induction heating cooker with a non-contact power feeding function according to claim 1, wherein the single power factor correction circuit is provided so as to be connectable to each inverter circuit. A switch that can be controlled by the load determining means;
It said switch selects either the pulsating DC voltage or constant DC voltage, a non-contact power supply function-equipped induction heating according to any one of claims 1-3, characterized by selectively applying to said inverter circuit Cooking device. The power factor correction circuit has a switching element that can be controlled by the load determination means,
The induction with a non-contact power feeding function according to any one of claims 1 to 3 , wherein the switching element selectively applies one of a pulsating DC voltage and a steady DC voltage to the inverter circuit. Cooking cooker. It is equipped with an operation unit for inputting the operation desired by the user,
The operation unit outputs a signal corresponding to the input operation,
It said load determining means, non-contact power supply function-equipped induction heating cooker according to any one of claims 1-5, characterized in that to determine the load by the output signal from the operation unit. The said operation part has the 1st and 2nd operation button for selecting the pulsating DC voltage applied to the said inverter circuit, or a steady DC voltage, The non-contact electric power feeding function is provided of Claim 6 characterized by the above-mentioned. Induction heating cooker. A coil voltage detector for detecting a coil voltage at both ends of the heating and feeding coil;
A coil current detector for detecting a high-frequency current flowing in the heating and feeding coil,
The load determination means includes a resistance component of a load placed on the top plate based on a coil voltage and a high frequency current detected when the frequency of the high frequency current supplied to the heating and feeding coil is swept, a load Measuring the frequency characteristic of either the reactance component of the coil or the phase difference between the coil voltage and the high-frequency current, and selectively applying a pulsating DC voltage or a steady DC voltage to the inverter circuit based on the measured frequency characteristic. The induction heating cooker with a non-contact electric power feeding function according to any one of claims 1 to 5 . The load discriminating unit applies a steady DC voltage to the inverter circuit regardless of the load placed on the top plate, and the resistance component of the load placed on the top plate, the reactance component of the load Or, after measuring the frequency characteristic of either the coil voltage or the phase difference between the high frequency current, selectively applying a pulsating DC voltage or a steady DC voltage to the inverter circuit based on the measured frequency characteristic. An induction heating cooker with a non-contact power feeding function according to claim 8 . A wireless transceiver connected to the load discriminating means;
The load has an RF tag capable of wireless communication with a wireless transceiver,
The RF tag wirelessly receives at least one of information on the voltage supplied to the inverter circuit among the pulsating DC voltage or the steady DC voltage, the resonance frequency of the resistance component of the power receiving coil, and the maximum rated power of the power receiving coil. non-contact power supply function-equipped induction heating cooker according to any one of claims 1-5, characterized in that it is configured to communicate wirelessly to the vessel. A top plate on which the load is placed;
A heating and feeding coil disposed below the top plate;
A rectifying circuit for rectifying a commercial AC power supply into a pulsating DC voltage whose voltage periodically varies;
A power factor correction circuit that converts the pulsating DC voltage rectified by the rectifier circuit into a steady DC voltage having a constant voltage magnitude;
An inverter circuit for supplying a high-frequency current to the heating and feeding coil;
Load discriminating means for selectively applying a pulsating DC voltage or a steady DC voltage to the inverter circuit according to the load placed on the top plate;
The load determining means determines whether the load placed on the top plate is an object to be heated that is induction-heated or a power-receiving device that is contactlessly powered, and An induction heating cooker with a non-contact power feeding function, wherein a pulsating DC voltage is selectively applied to the inverter circuit when it is determined and a steady DC voltage is selectively applied to the inverter circuit. A cooking system comprising an induction heating cooker with a non-contact power feeding function and a power receiving device,
Induction heating cooker
A heating and feeding coil comprising first and second heating and feeding coils;
A rectifying circuit for rectifying a commercial AC power supply into a pulsating DC voltage whose voltage periodically varies;
A power factor correction circuit that converts the pulsating DC voltage rectified by the rectifier circuit into a steady DC voltage having a constant voltage magnitude;
First and second inverter circuits for supplying a high-frequency current to the first and second heating and feeding coils;
Load discriminating means for discriminating a voltage to be applied to the inverter circuit among a pulsating DC voltage or a steady DC voltage;
A wireless transceiver connected to the load discriminating means,
The power receiving device
An RF tag capable of wireless communication with a wireless transceiver;
A power receiving coil,
The RF tag transmits at least one information among a voltage supplied to the inverter circuit among a pulsating DC voltage or a steady DC voltage, a resonance frequency of a resistance component of the power receiving coil, and a maximum rated power of the power receiving coil. Configured to communicate wirelessly with
The load discriminating means always applies a pulsating DC voltage from the rectifier circuit to the first inverter circuit, and pulsates according to the load placed on the top plate in the second inverter circuit. A cooking system characterized by selectively applying a DC voltage or a steady DC voltage . A power receiving device used with an induction heating cooker with a non-contact power feeding function,
The induction heating cooker includes first and second heating and feeding coils, a rectifying circuit that rectifies a commercial AC power supply into a pulsating DC voltage whose voltage periodically varies, and a pulsating DC rectified by the rectifying circuit. a power factor correction circuit for converting a voltage to a constant DC voltage is the magnitude of the voltage is constant, the first and second inverter circuit for supplying a high-frequency current to said first and second heating power supply coil, pulsating direct current A load discriminating unit for discriminating a voltage to be applied to the inverter circuit among a voltage or a steady DC voltage, and a radio transceiver connected to the load discriminating unit,
Power receiving equipment
An RF tag capable of wireless communication with a wireless transceiver;
A power receiving coil,
The RF tag transmits at least one information among a voltage supplied to the inverter circuit among a pulsating DC voltage or a steady DC voltage, a resonance frequency of a resistance component of the power receiving coil, and a maximum rated power of the power receiving coil. Configured to communicate wirelessly with
The load discriminating means always applies a pulsating DC voltage from the rectifier circuit to the first inverter circuit, and pulsates according to the load placed on the top plate in the second inverter circuit. A power receiving device that selectively applies a DC voltage or a steady DC voltage . Rectifying a commercial AC power supply into a pulsating DC voltage whose voltage magnitude periodically varies;
Converting the pulsating DC voltage into a steady DC voltage having a constant voltage magnitude;
Supplying a high-frequency current to the heating and feeding coil disposed below the top plate using an inverter circuit;
It is determined whether the load placed on the top plate is an object to be heated that is induction-heated or a power-receiving device that is contactlessly fed. If the load is determined to be the object to be heated, a pulsating direct current A method for controlling an induction heating cooker with a non-contact power feeding function , comprising: a step of selectively applying a steady DC voltage to the inverter circuit when a voltage is determined as the power receiving device . Detecting a coil voltage at both ends of the heating and feeding coil; and
Detecting a high-frequency current flowing in the heating and feeding coil;
Measuring a frequency characteristic of a resistance component of a load placed on the top plate based on a coil voltage and a high-frequency current detected when the frequency of the high-frequency current supplied to the heating and feeding coil is swept. ,
The induction heating cooker with a non-contact power feeding function according to claim 14, further comprising a step of selectively applying a pulsating DC voltage or a steady DC voltage to the inverter circuit based on the measured frequency characteristics. Control method.   Regardless of the load placed on the top plate, a steady DC voltage was applied to the inverter circuit, and the frequency characteristic of the resistance component of the load placed on the top plate was measured and then measured. The method for controlling an induction heating cooker with a non-contact power feeding function according to claim 14, further comprising a step of selectively applying a pulsating DC voltage or a steady DC voltage to the inverter circuit based on a frequency characteristic. The load has an RF tag capable of wireless communication with a wireless transceiver, and a power receiving coil.
At least one piece of information regarding the voltage supplied to the inverter circuit among the pulsating DC voltage or the steady DC voltage, the resonance frequency of the resistance component of the receiving coil, and the maximum rated power of the receiving coil stored in the RF tag The method for controlling an induction heating cooker with a non-contact power feeding function according to claim 16, further comprising a step of performing wireless communication.

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