WO2018225755A1 - Induction heating device - Google Patents

Induction heating device Download PDF

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Publication number
WO2018225755A1
WO2018225755A1 PCT/JP2018/021632 JP2018021632W WO2018225755A1 WO 2018225755 A1 WO2018225755 A1 WO 2018225755A1 JP 2018021632 W JP2018021632 W JP 2018021632W WO 2018225755 A1 WO2018225755 A1 WO 2018225755A1
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WIPO (PCT)
Prior art keywords
switching element
heating
heating coils
coils
control unit
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PCT/JP2018/021632
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French (fr)
Japanese (ja)
Inventor
今井　慎
貴之 廣川
Original Assignee
パナソニックＩｐマネジメント株式会社
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Priority to JP2019523926A priority Critical patent/JP7186344B2/en
Publication of WO2018225755A1 publication Critical patent/WO2018225755A1/en

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    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B6/00—Heating by electric, magnetic or electromagnetic fields
    • H05B6/02—Induction heating
    • H05B6/10—Induction heating apparatus, other than furnaces, for specific applications
    • H05B6/12—Cooking devices

Definitions

  • the present disclosure relates to an induction heating apparatus.
  • Patent Document 1 Conventionally, in the field of induction heating devices, techniques for heating various metal loads including aluminum pans have been developed (see, for example, Patent Document 1).
  • FIG. 14 is a block diagram of the induction heating apparatus described in Patent Document 1.
  • the conventional induction heating apparatus includes a choke coil 102, a smoothing capacitor 103, a resonance capacitor 104, a heating coil 105, switching elements 106 and 107, a current detection unit 109, and a control unit 110.
  • One end of the choke coil 102 is connected to the positive electrode of the commercial power source 101.
  • the smoothing capacitor 103 is connected between the other end of the choke coil 102 and the negative electrode of the commercial power source 101.
  • One end of the switching element 106 is connected to one end of the smoothing capacitor 103, and the other end of the switching element 106 is connected to one end of the switching element 107.
  • the other end of the switching element 107 is connected to the other end of the smoothing capacitor 103.
  • the resonance capacitor 104 and the heating coil 105 are connected in series to constitute a resonance circuit.
  • One end of the resonance circuit is connected to a connection point between the switching element 106 and the switching element 107.
  • the other end of the resonance circuit is connected to the other end of the smoothing capacitor 103.
  • the current detection unit 109 monitors the input current supplied from the commercial power source 101.
  • Control unit 110 controls switching elements 106 and 107.
  • the resonance frequency of the resonance circuit is determined according to the inductance of the heating coil 105 coupled to the pan 108 and the capacitance of the resonance capacitor 104. In the above prior art, the resonance frequency is set to at least twice the drive frequency of the switching elements 106 and 107.
  • the iron pan has a low thermal conductivity, when one heating coil is used, the magnetic field contributing to heating becomes stronger on the winding of the heating coil, and the heating distribution of the pan becomes the same shape as the heating coil. Therefore, it is difficult to heat the pan uniformly.
  • Aluminum pans have high thermal conductivity, so even when a single heating coil is used, the pans can be heated uniformly. However, since the pan made of aluminum has a low specific resistance value of the pan itself, it is necessary to apply a high-frequency large current to the heating coil. As a result, loss increases and heating efficiency decreases.
  • the present disclosure solves the above-described problems of the prior art.
  • uniform heating can be performed, and when heating an aluminum pan, high-frequency current is reduced. It is an object of the present invention to provide an induction heating device that can be used.
  • the induction heating device includes a top plate, a plurality of heating coils, an inverter, a control unit, and a determination unit.
  • the top plate is configured to place an object to be heated.
  • the plurality of heating coils are disposed below the top plate.
  • the inverter is configured to supply power to the plurality of heating coils.
  • the control unit is configured to control the inverter.
  • the determination unit is configured to determine whether the object to be heated is an iron-based load or an aluminum-based load.
  • the control unit is configured to control the direction of the current flowing through the plurality of heating coils according to the determination result by the determination unit.
  • the iron-based pan can be heated uniformly, and the aluminum-based pan can be efficiently heated.
  • uniform heating can be performed when an iron pan is heated, and high-frequency current can be reduced when an aluminum pan is heated.
  • FIG. 1 is a block configuration diagram of the induction heating apparatus according to the first embodiment.
  • FIG. 2 is a block configuration diagram showing the configuration, arrangement, and connection of the heating coil in the induction heating apparatus according to the first embodiment.
  • FIG. 3A is a waveform diagram of a drive signal of a switching element and a current flowing through a heating coil when heating an iron-based pan.
  • FIG. 3B is a diagram schematically showing the direction of the current flowing through the heating coil when heating an iron-based pan.
  • FIG. 4A is a waveform diagram of a drive signal of a switching element and a current flowing through a heating coil when an aluminum pan is heated.
  • FIG. 4B is a diagram schematically showing the direction of the current flowing through the heating coil when heating an aluminum pan.
  • FIG. 4A is a waveform diagram of a drive signal of a switching element and a current flowing through a heating coil when an aluminum pan is heated.
  • FIG. 4B is a diagram schematically showing the direction of the current flowing through
  • FIG. 5A is a diagram showing the relationship between the distance from the center point of one or more heating coils and the temperature rise ratio.
  • FIG. 5B is a diagram schematically showing the shape and center point of one or a plurality of heating coils.
  • FIG. 6A is a diagram showing the relationship between the distance from the center point and the temperature rise ratio in a system equipped with four heating coils.
  • FIG. 6B is a diagram schematically showing the arrangement and center point of the heating coil.
  • FIG. 7 is a block diagram of the induction heating apparatus according to the second embodiment.
  • FIG. 8 is a block configuration diagram showing the configuration, arrangement, and connection of the heating coil in the induction heating apparatus according to the second embodiment.
  • FIG. 9 is a block diagram of the induction heating apparatus according to the third embodiment.
  • FIG. 10A is a diagram for explaining the operation of the induction heating device according to the third embodiment.
  • FIG. 10B is a diagram for explaining the operation of the induction heating apparatus according to Embodiment 3.
  • FIG. 10C is a diagram for explaining the operation of the induction heating apparatus according to Embodiment 3.
  • FIG. 10D is a diagram for explaining the operation of the induction heating device according to the third embodiment.
  • FIG. 11A is a schematic diagram illustrating an example of the arrangement and connection method of the heating coils of the induction heating apparatus according to Embodiment 3.
  • FIG. 11B is a schematic diagram illustrating an example of the arrangement and connection method of the heating coils of the induction heating apparatus according to Embodiment 3.
  • FIG. 11A is a schematic diagram illustrating an example of the arrangement and connection method of the heating coils of the induction heating apparatus according to Embodiment 3.
  • FIG. 11B is a schematic diagram illustrating an example of the arrangement and connection method of the heating coils of the induction heating apparatus according
  • FIG. 12A is a waveform diagram showing a drive signal supplied to each switching element and a current flowing through each heating coil.
  • FIG. 12B is a schematic diagram illustrating the direction of current flowing through each heating coil.
  • FIG. 13A is a waveform diagram showing a drive signal supplied to each switching element and a current flowing through each heating coil.
  • FIG. 13B is a schematic diagram illustrating the direction of current flowing through each heating coil.
  • FIG. 14 is a block diagram of a conventional induction heating apparatus.
  • the induction heating device includes a top plate, a plurality of heating coils, an inverter, a control unit, and a determination unit.
  • the top plate is configured to place an object to be heated.
  • the plurality of heating coils are disposed below the top plate.
  • the inverter is configured to supply power to the plurality of heating coils.
  • the control unit is configured to control the inverter.
  • the determination unit is configured to determine whether the object to be heated is an iron-based load or an aluminum-based load.
  • the control unit is configured to control the direction of the current flowing through the plurality of heating coils according to the determination result by the determination unit.
  • the control unit when the determination unit determines that the object to be heated is an iron-based load, the control unit includes a plurality of heating coils. It is comprised so that an electric current may be sent through two adjacent heating coils to a reverse direction.
  • the control unit when the determination unit determines that the object to be heated is an aluminum-based load, the control unit includes a plurality of heating coils. It is comprised so that an electric current may be sent through the two adjacent heating coils in the same direction.
  • the distance between two adjacent heating coils is set to 40 mm or less.
  • the plurality of heating coils include four heating coils, each including two heating coils connected in series or in parallel. Are arranged so as to intersect in an X shape.
  • an induction heating apparatus wherein a DC power source, first to fourth switching elements, first to fourth resonance capacitors, and first and second heating elements are provided.
  • the first switching element and the second switching element are connected in series to each other and are connected in parallel to the DC power supply.
  • the third switching element and the fourth switching element are connected in series to each other and are connected in parallel to the DC power supply.
  • One end of the first heating coil is connected to a connection point between the first switching element and the second switching element.
  • One end of the first resonance capacitor is connected to the other end of the first heating coil.
  • One end of the second heating coil is connected to a connection point between the third switching element and the fourth switching element.
  • the fourth resonance capacitor has one end connected to the other end of the second heating coil and the other end connected to the other end of the first resonance capacitor.
  • the third resonance capacitor has one end connected to the connection point between the first resonance capacitor and the fourth resonance capacitor, and the other end connected to the positive electrode of the DC power supply.
  • the second resonance capacitor has one end connected to the connection point between the first resonance capacitor and the fourth resonance capacitor, and the other end connected to the negative electrode of the DC power supply.
  • the control unit turns on the first switching element and the second switching element alternately, and turns on the third switching element and the fourth switching element alternately.
  • the control unit turns on the first switching element and the third switching element at the same time and turns on the second switching element and the fourth switching element at the same time when the object to be heated is a non-magnetic material.
  • the control unit turns on the first switching element and the fourth switching element simultaneously and turns on the second switching element and the third switching element simultaneously when the object to be heated is a magnetic material.
  • FIG. 1 is a block configuration diagram of induction heating apparatus 20A according to the first embodiment.
  • the induction heating device 20A includes a rectifier circuit 2, a choke coil 3, a capacitor 4, switching elements 5, 6, 9, and 10, heating coils 7a, 7b, 11a, and 11b, a resonant capacitor 8, and a control unit. 14, a current detection unit 15, and voltage detection units 16 and 17.
  • the rectifier circuit 2 is a diode bridge that rectifies the AC voltage from the commercial power source 1.
  • One end of the choke coil 3 is connected to the positive output terminal of the rectifier circuit 2.
  • the other end of the choke coil 3 is connected to one end of the capacitor 4.
  • the other end of the capacitor 4 is connected to the negative output end of the rectifier circuit 2.
  • the choke coil 3 and the capacitor 4 constitute a filter unit.
  • the current detection unit 15 is provided between the other end of the capacitor 4 and the negative output end of the rectifier circuit 2.
  • the switching element 5 and the switching element 6 are composed of IGBTs (Insulated Gate Bipolar Transistors) or the like, and incorporate diodes connected in opposite directions.
  • IGBTs Insulated Gate Bipolar Transistors
  • the heating coils 7a and 7b and the resonant capacitor 8 are connected in series.
  • a connection point A between the switching element 5 and the switching element 6 is connected to one end of the heating coil 7a.
  • the other end of the heating coil 7a is connected to one end of the heating coil 7b.
  • the other end of the heating coil 7 b is connected to one end of the resonance capacitor 8.
  • the other end of the resonant capacitor 8 is connected to a connection point B connected to the drain of the switching element 6.
  • the switching elements 5 and 6 constitute an inverter 18 that is a first inverter.
  • the inverter 18 converts the power processed by the filter unit into alternating current, and supplies the alternating current power to the heating coil 7a and the heating coil 7b.
  • the voltage detector 16 is provided between the heating coil 7b and the resonance capacitor 8, and detects the voltage at the connection point between the heating coil 7b and the resonance capacitor 8.
  • the switching element 9 and the switching element 10 are composed of IGBTs or the like, and incorporate diodes connected in the reverse direction.
  • the heating coils 11a and 11b and the resonance capacitor 12 are connected in series.
  • a connection point C between the switching element 9 and the switching element 10 is connected to one end of the heating coil 11a.
  • the other end of the heating coil 11a is connected to one end of the heating coil 11b.
  • the other end of the heating coil 11 b is connected to one end of the resonance capacitor 12.
  • the other end of the resonant capacitor 12 is connected to a connection point D connected to the drain of the switching element 10.
  • the switching elements 9 and 10 constitute an inverter 19 that is a second inverter.
  • the inverter 19 converts the power processed by the filter unit into alternating current, and supplies the alternating current power to the heating coil 11a and the heating coil 11b.
  • the voltage detector 17 is provided between the heating coil 11b and the resonance capacitor 12, and detects the voltage at the connection point between the heating coil 11b and the resonance capacitor 12.
  • the inverter 19 is connected to the inverter 18 in parallel.
  • the inverter 18 and the inverter 19 share the rectifier circuit 2, the choke coil 3, and the capacitor 4.
  • An insulating and heat-resistant ceramic top plate (not shown) is provided above the heating coils 7a, 7b, 11a, and 11b.
  • the pan 13 that is an object to be heated is placed on the top plate.
  • the heating coils 7a, 7b, 11a, 11b have the same shape, size, winding direction and different centers, and are arranged on the same plane (see FIG. 2).
  • the control unit 14 is composed of a microcomputer and controls the switching elements 5, 6, 9, and 10.
  • the control unit 14 includes a determination unit 14 a that determines the material of the pan 13.
  • the determination unit 14a determines whether the pan 13 is made of iron or aluminum based on the values detected by the current detection unit 15 and the voltage detection units 16 and 17.
  • details of the determination unit 14a will be described.
  • control unit 14 includes a current detection unit 15 and a voltage detection unit in a case where an iron-based pan or an aluminum-based pan is placed on the top plate and the switching elements 5 and 9 are turned on for a predetermined period.
  • the values measured by 16, 17 are stored as reference data.
  • control unit 14 When the pan 13 is placed on the top plate, the control unit 14 turns on the switching elements 5 and 9 for a predetermined period until the heating is started, and the current detection unit 15 and the voltage detection units 16 and 17 Get the measured value.
  • the control unit 14 determines the material of the pan 13 by comparing the actual measurement value with the reference data. Specifically, the series resistance value and the series inductance value are different between the iron-based pan and the aluminum-based pan. The voltage value relative to the current value in the case of an iron-based pan is lower than that in the case of an aluminum-based pan. Using this, the control unit 14 determines the material of the pan 13.
  • FIG. 2 is a block configuration diagram showing the configuration, arrangement, and connection of the heating coils 7a, 7b, 11a, and 11b in the induction heating device 20A.
  • the heating coils 7a, 7b, 11a, and 11b have a clockwise winding direction from the outside toward the inside.
  • the heating coils 7a and 7b are connected in series with the inner end of the heating coil 7a being connected to the outer end of the heating coil 7b.
  • the outer end of the heating coil 7a is connected to the connection point A.
  • the inner end of the heating coil 7 b is connected to the resonance capacitor 8.
  • the heating coils 11a and 11b are connected in series with the inner end of the heating coil 11a being connected to the outer end of the heating coil 11b.
  • the outer end of the heating coil 11a is connected to the connection point C.
  • the inner end of the heating coil 11 b is connected to the resonance capacitor 12.
  • the heating coils 7a, 7b, 11a, 11b are arranged so that the heating coils 7a, 7b connected in series intersect with the heating coils 11a, 11b connected in series in an X shape.
  • the inverter 18 drives the heating coils 7a and 7b, and the inverter 19 drives the heating coils 11a and 11b.
  • FIG. 3A is a waveform diagram of drive signals of four switching elements and currents flowing through four heating coils when heating an iron-based pan.
  • FIG. 3B is a diagram schematically showing the directions of currents flowing through each of the four heating coils when heating an iron-based pan.
  • control unit 14 drives the switching elements 5 and 9 with the same drive signal.
  • the control unit 14 drives the switching elements 6 and 10 with a drive signal different from the drive signals for the switching elements 5 and 9.
  • FIG. 4A is a waveform diagram of drive signals of four switching elements and currents flowing through four heating coils when heating an aluminum pan.
  • FIG. 4B is a diagram schematically showing the directions of currents flowing through each of the four heating coils when heating an aluminum pan.
  • control unit 14 drives the switching elements 5 and 10 with the same drive signal.
  • the control unit 14 drives the switching elements 6 and 9 with a drive signal different from the drive signals for the switching elements 5 and 10.
  • control unit 14 is composed of a microcomputer.
  • the control unit 14 is not limited to a microcomputer. However, if a programmable microcomputer is used, the processing contents can be easily changed, and the degree of design freedom can be increased.
  • control unit 14 may be physically composed of one or a plurality of elements.
  • control unit 14 and the determination unit 14a may be implemented by separate elements. In this case, it can be considered that these plural elements correspond to one control unit.
  • the control unit 14 Before starting heating the pan 13 placed on the top plate above the heating coils 7a, 7b, 11a, 11b, the control unit 14 supplies a drive signal to the switching element for a predetermined period. Based on the detection values of the current detection unit 15 and the voltage detection units 16 and 17 at that time, the determination unit 14a determines whether the pan is an aluminum pan or an iron pan.
  • aluminum pots include not only aluminum pots, but also copper pots, multi-layer pots with a high proportion of aluminum, and the like.
  • Iron-based pots include enamel pots and magnetic stainless steel pots.
  • control unit 14 supplies a drive signal to the switching elements 5, 6, 9, and 10 as illustrated in FIG. 3A.
  • the current flowing through the heating coils 7a and 7b is in phase with the current flowing through the heating coils 11a and 11b. That is, when a current flows from the connection point A through the heating coils 7a and 7b to the connection point B, a current flows from the connection point C through the heating coils 11a and 11b to the connection point D (see FIGS. 1 and 2). .
  • the magnetic field cancels out in a region between two adjacent heating coils, and local excessive heating is prevented, whereby the pan 13 can be heated uniformly.
  • control unit 14 supplies a drive signal to the switching elements 5, 6, 9, and 10 as illustrated in FIG. 4A.
  • the current flowing through the heating coils 7a and 7b is in opposite phase to the current flowing through the heating coils 11a and 11b. That is, when a current flows from the connection point A through the heating coils 7a and 7b to the connection point B, a current flows from the connection point D through the heating coils 11b and 11a to the connection point C (see FIGS. 1 and 2). .
  • heating coils 7a and 11a As shown in FIG. 4B, current flows in the same direction in two adjacent heating coils, namely, heating coils 7a and 11a, heating coils 11a and 7b, heating coils 7b and 11b, and heating coils 11b and 7a. Flowing.
  • the resistance value of the load including the pan 13 as viewed from the heating coil increases, and even an aluminum pan having a low specific resistance value can be sufficiently heated with a small current.
  • FIG. 5A shows the relationship between the distance from the center point of one or more heating coils and the temperature rise ratio.
  • FIG. 5B schematically shows the shape and center point of one or more heating coils.
  • the center point of one or a plurality of heating coils is simply referred to as a center point.
  • the horizontal axis indicates the distance from the center point.
  • the vertical axis represents the ratio of the temperature rise value at a point away from the center point by the distance indicated by the horizontal axis with respect to the maximum value of the temperature rise value.
  • the temperature increase ratio decreases near the center point and at a point away from the center point.
  • the variation in temperature rise ratio is smaller than in the case of one heating coil.
  • FIG. 6A shows the relationship between the distance from the center point and the temperature rise ratio in a system equipped with four heating coils.
  • FIG. 6B schematically shows the arrangement and center point of the four heating coils.
  • the distance between two adjacent heating coils is set to 60 mm.
  • These systems are provided with four heating coils with an inner diameter of 25 mm and an outer diameter of 76 mm. As described above, these systems are configured such that currents flow in opposite directions to two adjacent heating coils.
  • the temperature increase ratio decreases at a point near the center point and a point away from the center point.
  • the decrease in the temperature increase ratio is the smallest among the three cases.
  • the temperature increase ratio does not decrease by more than 20% compared to the case where the distance between two adjacent heating coils is 20 mm.
  • the temperature increase ratio decreases by 20% or more compared to the case where the distance between two adjacent heating coils is 20 mm.
  • the induction heating device 20A has four heating coils. However, the number of heating coils is not limited to this. When heating an iron-based pan, it is only necessary to configure the induction heating device so that currents flow in opposite directions with respect to two adjacent heating coils. When heating an aluminum pan, it is only necessary to configure the induction heating device so that current flows in the same direction with respect to two adjacent heating coils.
  • FIG. 7 is a block configuration diagram of the induction heating apparatus 20B according to the present embodiment.
  • FIG. 8 is a block configuration diagram showing the configuration, arrangement, and connection of the heating coils 7a, 7b, 11a, and 11b in the induction heating device 20B.
  • the heating coils 7a and 7b are connected in parallel, and the heating coils 11a and 11b are connected in parallel.
  • the heating coils 7 a and 7 b connected in parallel are connected in series with the resonance capacitor 8.
  • the heating coils 11 a and 11 b connected in parallel are connected in series with the resonance capacitor 12.
  • Other configurations are the same as those of the first embodiment.
  • the heating coils 7a, 7b, 11a, 11b are arranged so that the heating coils 7a, 7b connected in parallel intersect with the heating coils 11a, 11b connected in parallel in an X shape.
  • in the induction heating device 20B when heating an iron pan, currents flow in opposite directions with respect to two adjacent heating coils.
  • current flows in the same direction with respect to two adjacent heating coils.
  • FIG. 9 is a block configuration diagram of induction heating device 20C according to the present embodiment.
  • the induction heating device 20 ⁇ / b> C includes a DC power supply 31, resonant capacitors 32, 33, 38, 39, switching elements 35, 36, 41, 42, heating coils 34, 40, and a control unit 37.
  • the heating coils 34 and 40 correspond to first and second heating coils, respectively.
  • the switching elements 35, 36, 41, and 42 correspond to first, second, third, and fourth switching elements, respectively.
  • the resonant capacitors 32, 33, 38, and 39 correspond to the first, second, third, and fourth resonant capacitors, respectively.
  • Switching elements 35, 36, 41, and 42 are formed of IGBTs or the like, and are connected in the reverse direction and incorporate diodes.
  • the switching element 35 is connected in series with the switching element 36.
  • the switching elements 35 and 36 are connected to the DC power supply 31 in parallel. Specifically, the emitter of the switching element 35 is connected to the collector of the switching element 36. The collector of the switching element 35 is connected to the positive electrode of the DC power supply 31. The switching element 36 emitter is connected to the negative electrode of the DC power supply 31.
  • the switching element 41 is connected in series with the switching element 42.
  • the switching elements 41 and 42 are connected to the DC power supply 31 in parallel.
  • the emitter of the switching element 41 is connected to the collector of the switching element 42.
  • the collector of the switching element 41 is connected to the positive electrode of the DC power supply 31.
  • the emitter of the switching element 42 is connected to the negative electrode of the DC power supply 31.
  • the switching elements 35 and 36 constitute an inverter 45 that is a first inverter.
  • the switching elements 41 and 42 constitute an inverter 46 that is a second inverter.
  • One end of the heating coil 34 is connected to the connection point (connection point E) of the switching elements 35 and 36.
  • One end of the resonance capacitor 32 is connected to the other end of the heating coil 34.
  • connection point G connection point G of the switching elements 41 and 42.
  • the resonant capacitor 39 has one end connected to the other end of the heating coil 40 and the other end connected to the other end of the resonant capacitor 32.
  • the resonance capacitor 38 has one end connected to the connection point (connection point F) of the resonance capacitors 32 and 39 and the other end connected to the positive electrode of the DC power supply 31.
  • the resonance capacitor 33 has one end connected to the connection point (connection point F) of the resonance capacitors 32 and 39 and the other end connected to the negative electrode of the DC power supply 31.
  • the current detector 43 is connected to the negative electrode of the DC power supply 31 and detects the current flowing through the induction heating device 20C.
  • the voltage detection unit 44 is connected to the connection point F and detects the voltage at the connection point F.
  • the control unit 37 controls the switching elements 35 and 36 included in the inverter 45 and the switching elements 41 and 42 included in the inverter 46.
  • the control part 37 has the determination part 37a which determines the material of the pan which is a to-be-heated material.
  • the determination unit 37a determines whether the material of the pan is a magnetic material or a non-magnetic material based on the values detected by the current detection unit 43 and the voltage detection unit 44.
  • the determination method of the determination unit 37a is the same as that of the determination unit 14a described above, and detailed description thereof is omitted.
  • the controller 37 turns on the switching elements 35 and 36 alternately and turns on the switching elements 41 and 42 alternately. At the same time, the control unit 37 turns on the switching elements 35 and 41 at the same time, and turns on the switching elements 36 and 42 at the same time.
  • control unit 37 When the pan is made of a magnetic material, the control unit 37 turns on the switching elements 35 and 36 alternately and turns on the switching elements 41 and 42 alternately. At the same time, the control unit 37 turns on the switching elements 35 and 42 simultaneously and turns on the switching elements 36 and 41 simultaneously.
  • An insulating and heat-resistant ceramic top plate (not shown) is provided above the heating coils 34 and 40.
  • a pan (not shown) is placed on the top plate.
  • the heating coils 34 and 40 have the same shape, size and winding direction, and are arranged adjacent to each other on the same plane.
  • control unit 37 changes the conduction pattern for the switching elements 35, 36, 41 and 42, thereby changing the direction of the current flowing through the heating coils 34 and 40. Can be changed.
  • control unit 37 can flow current through the heating coils 34 and 40 in a direction in which the magnetic fields generated from the heating coils 34 and 40 are strengthened or cancel each other. For this reason, highly efficient heating and uniform heating can be realized.
  • the capacitance of the resonance capacitors 33 and 38 is set sufficiently smaller than the capacitance of the resonance capacitors 32 and 39, the combined capacitance of the resonance capacitors on the path through which the current flows can be changed by changing the conduction pattern.
  • 10A to 10D are diagrams for explaining the operation of the induction heating device 20C.
  • the pan is made of a non-magnetic material.
  • FIG. 10A when the switching element 35 is turned on and the switching element 36 is turned off, a current path including the DC power supply 31, the resonant capacitors 32 and 33, the heating coil 34, and the switching element 35 is formed.
  • the current path including the heating coil 34 has a combined capacity of the resonance capacitors 32 and 33.
  • the current path including the heating coil 40 has a combined capacity of the resonance capacitors 38 and 39.
  • the current path including the heating coil 34 has the combined capacity of the resonance capacitors 32 and 38.
  • the current path including the heating coil 40 has a combined capacity of the resonance capacitors 33 and 39.
  • this current path has a combined capacity of the resonance capacitors 32 and 39.
  • this current path has a combined capacity of the resonance capacitors 32 and 39.
  • the capacitances of the resonance capacitors 32 and 39 are set sufficiently larger than the capacitances of the resonance capacitors 33 and 38. Accordingly, the combined capacity of the resonance capacitors can be changed by changing the combination of the resonance capacitors depending on whether the pan is made of a magnetic material or not.
  • the combined capacity of the resonant capacitors when heating a nonmagnetic pot is smaller than that when heating a magnetic pot shown in FIGS. 10C and 10D.
  • the combined capacity of the resonant capacitor when heating a non-magnetic pot is smaller than when heating a magnetic pot.
  • the combined capacity of the resonant capacitors when heating a magnetic pot is better than when heating a nonmagnetic pot.
  • FIG. 11A and 11B are schematic diagrams showing the arrangement and connection of heating coils in the induction heating apparatus 20C.
  • both the heating coil 34 and the heating coil 40 are configured by one heating coil.
  • the heating coils 34 and 40 have a clockwise winding direction from the outside to the inside, and are arranged adjacent to each other.
  • the outer end of the heating coil 34 is connected to the connection point E.
  • the inner end of the heating coil 34 is connected to the resonance capacitor 32 (see FIG. 9).
  • each of the heating coils 34 and 40 is composed of a series body of two heating coils. These four heating coils have a clockwise winding direction from the outside to the inside.
  • the two heating coils constituting the heating coil 34 are connected in series with the inner end of one heating coil connected to the outer end of the other heating coil.
  • the outer end of one heating coil is connected to the connection point E.
  • the inner end of the other heating coil is connected to the resonance capacitor 32.
  • the two heating coils constituting the heating coil 40 are connected in series with the inner end of one heating coil connected to the outer end of the other heating coil.
  • the outer end of one heating coil is connected to the resonance capacitor 39.
  • the inner end of the other heating coil is connected to the connection point G.
  • These four heating coils are arranged so that the two heating coils connected in series constituting the heating coil 34 intersect the two heating coils connected in series constituting the heating coil 40 in an X-shape.
  • FIG. 12A is a waveform diagram showing drive signals supplied to the switching elements 35, 36, 41, and 42 and currents flowing through the heating coils 34 and 40.
  • 12A is a waveform diagram in the case where heating coils 34 and 40 are arranged as shown in FIG. 11A and a nonmagnetic material pan is heated as shown in FIGS. 10A and 10B.
  • FIG. 12B shows the direction of the current flowing through the heating coils 34 and 40 in the period t1 shown in FIG. 12A.
  • FIG. 13A is a waveform diagram showing drive signals supplied to the switching elements 35, 36, 41, 42 and currents flowing through the heating coils 34, 40.
  • FIG. 13A is a waveform diagram in the case where the heating coils 34 and 40 are arranged as shown in FIG. 11A and a magnetic pot is heated as shown in FIGS. 10C and 10D.
  • FIG. 13B shows the direction of the current flowing through the heating coils 34 and 40 in the period t1 shown in FIG. 13A.
  • the pan is placed on the top plate above the heating coils 34 and 40.
  • the control unit 37 supplies a drive signal to each switching element for a predetermined time, and receives values detected by the current detection unit 43 and the voltage detection unit 44 during that time.
  • the determination unit 37a determines whether the pan is a non-magnetic material or a magnetic material based on these values.
  • Nonmagnetic material pans include aluminum pans, copper pans, and multi-layer pans with a high percentage of aluminum.
  • Magnetic pots include enamel pots and magnetic stainless steel pots.
  • the control unit 37 supplies the same drive signal to the switching elements 35 and 41 as shown in FIG. Are supplied with the same drive signal.
  • the drive signals for the switching elements 35 and 41 are different from the drive signals for the switching elements 36 and 42.
  • the control unit 37 supplies the same drive signal to the switching elements 35 and 42 as shown in FIG. The same drive signal is supplied.
  • the drive signals for the switching elements 35 and 42 are different from the drive signals for the switching elements 36 and 41.
  • control unit 37 changes the conduction pattern of the switching elements 35, 36, 41, and 42 according to the material of the pan, thereby synthesizing the resonant capacitor without using a relay.
  • the capacity can be changed.
  • This disclosure can be applied to an induction heating cooker that can heat both iron-based pans and aluminum-based pans.

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Abstract

This induction heating device has a top plate, a plurality of heating coils, an inverter, a control unit, and a determining unit. In the induction heating device, the top plate is configured such that a subject to be heated is to be placed thereon, and the heating coils are disposed below the top plate. The inverter is configured so as to supply power to the heating coils. The control unit is configured so as to control the inverter. The determining unit is configured so as to determine whether the subject to be heated is an iron-based load or an aluminum-based load. The control unit is configured so as to control, in accordance with determination results obtained by the determining unit, the direction of a current that is to flow in the heating coils. According to the embodiment of the present invention, iron-based pans can be uniformly heated, and aluminum-based pans can be efficiently heated.

Description

誘導加熱装置Induction heating device
　本開示は、誘導加熱装置に関する。 The present disclosure relates to an induction heating apparatus.
　従来、誘導加熱装置の分野において、アルミニウム製の鍋を含む各種の金属負荷を加熱する技術が開発されている（例えば、特許文献１参照）。 Conventionally, in the field of induction heating devices, techniques for heating various metal loads including aluminum pans have been developed (see, for example, Patent Document 1).
　図１４は、特許文献１に記載された誘導加熱装置のブロック構成図である。 FIG. 14 is a block diagram of the induction heating apparatus described in Patent Document 1.
　図１４に示すように、従来の誘導加熱装置は、チョークコイル１０２と平滑コンデンサ１０３と共振コンデンサ１０４と加熱コイル１０５とスイッチング素子１０６および１０７と電流検知部１０９と制御部１１０とを備える。 As shown in FIG. 14, the conventional induction heating apparatus includes a choke coil 102, a smoothing capacitor 103, a resonance capacitor 104, a heating coil 105, switching elements 106 and 107, a current detection unit 109, and a control unit 110.
　チョークコイル１０２の一端は、商用電源１０１の正極に接続される。平滑コンデンサ１０３は、チョークコイル１０２の他端と商用電源１０１の負極と間に接続される。スイッチング素子１０６の一端は平滑コンデンサ１０３の一端に接続され、スイッチング素子１０６の他端はスイッチング素子１０７の一端に接続される。スイッチング素子１０７の他端は、平滑コンデンサ１０３の他端に接続される。 One end of the choke coil 102 is connected to the positive electrode of the commercial power source 101. The smoothing capacitor 103 is connected between the other end of the choke coil 102 and the negative electrode of the commercial power source 101. One end of the switching element 106 is connected to one end of the smoothing capacitor 103, and the other end of the switching element 106 is connected to one end of the switching element 107. The other end of the switching element 107 is connected to the other end of the smoothing capacitor 103.
　共振コンデンサ１０４と加熱コイル１０５とは直列に接続されて、共振回路を構成する。共振回路の一端は、スイッチング素子１０６とスイッチング素子１０７との接続点に接続される。共振回路の他端は、平滑コンデンサ１０３の他端に接続される。電流検知部１０９は、商用電源１０１から供給される入力電流を監視する。 The resonance capacitor 104 and the heating coil 105 are connected in series to constitute a resonance circuit. One end of the resonance circuit is connected to a connection point between the switching element 106 and the switching element 107. The other end of the resonance circuit is connected to the other end of the smoothing capacitor 103. The current detection unit 109 monitors the input current supplied from the commercial power source 101.
　制御部１１０は、スイッチング素子１０６および１０７を制御する。共振回路の共振周波数は、鍋１０８と結合した加熱コイル１０５のインダクタンスと共振コンデンサ１０４の容量とに応じて決定される。上記従来技術では、共振周波数は、スイッチング素子１０６および１０７の駆動周波数の２倍以上に設定される。 Control unit 110 controls switching elements 106 and 107. The resonance frequency of the resonance circuit is determined according to the inductance of the heating coil 105 coupled to the pan 108 and the capacitance of the resonance capacitor 104. In the above prior art, the resonance frequency is set to at least twice the drive frequency of the switching elements 106 and 107.
　上記従来技術によれば、スイッチング素子１０６、１０７のスイッチング周波数を変えることなく、鉄製の鍋のみならずアルミニウム製の鍋１０８を加熱することが可能となる。 According to the above prior art, it is possible to heat not only the iron pot but also the aluminum pot 108 without changing the switching frequency of the switching elements 106 and 107.
特開２００１－１６０４８４号公報JP 2001-160484 A
　しかしながら、鉄製の鍋は熱伝導率が低いため、一つの加熱コイルを用いた場合、加熱に寄与する磁界は加熱コイルの巻線上が強くなり、鍋の加熱分布は加熱コイルと同じ形となる。そのため、鍋を均一に加熱することは困難である。 However, since the iron pan has a low thermal conductivity, when one heating coil is used, the magnetic field contributing to heating becomes stronger on the winding of the heating coil, and the heating distribution of the pan becomes the same shape as the heating coil. Therefore, it is difficult to heat the pan uniformly.
　アルミ製の鍋は熱伝導率が高いため、一つの加熱コイルを用いた場合でも、鍋を均一に加熱することが可能である。しかしながら、アルミ製の鍋は鍋自体の固有抵抗値が低いため、加熱コイルに高周波数の大電流を印加する必要がある。そのため、損失が大きくなり、加熱効率が低下する。 Aluminum pans have high thermal conductivity, so even when a single heating coil is used, the pans can be heated uniformly. However, since the pan made of aluminum has a low specific resistance value of the pan itself, it is necessary to apply a high-frequency large current to the heating coil. As a result, loss increases and heating efficiency decreases.
　本開示は、上記従来技術の問題点を解決するもので、鉄製の鍋を加熱する場合には均一な加熱を行うことが可能で、アルミ製の鍋を加熱する場合には高周波電流を低減することが可能な誘導加熱装置を提供することを目的とする。 The present disclosure solves the above-described problems of the prior art. When heating an iron pan, uniform heating can be performed, and when heating an aluminum pan, high-frequency current is reduced. It is an object of the present invention to provide an induction heating device that can be used.
　本開示の一態様の誘導加熱装置は、トッププレートと複数の加熱コイルとインバータと制御部と判定部とを有する。誘導加熱装置は、トッププレートは、被加熱物を載置するように構成され。複数の加熱コイルは、トッププレートの下方に配置される。インバータは、複数の加熱コイルに電力を供給するように構成される。制御部は、インバータを制御するように構成される。判定部は、被加熱物が鉄系の負荷であるか、アルミ系の負荷であるかを判定するように構成される。制御部は、判定部による判定結果に応じて、複数の加熱コイルに流れる電流の向きを制御するように構成される。 The induction heating device according to one aspect of the present disclosure includes a top plate, a plurality of heating coils, an inverter, a control unit, and a determination unit. In the induction heating apparatus, the top plate is configured to place an object to be heated. The plurality of heating coils are disposed below the top plate. The inverter is configured to supply power to the plurality of heating coils. The control unit is configured to control the inverter. The determination unit is configured to determine whether the object to be heated is an iron-based load or an aluminum-based load. The control unit is configured to control the direction of the current flowing through the plurality of heating coils according to the determination result by the determination unit.
　本態様によれば、鉄系の鍋に対しては均一に加熱し、アルミ系の鍋に対しては効率的に加熱することができる。 According to this aspect, the iron-based pan can be heated uniformly, and the aluminum-based pan can be efficiently heated.
　本態様によれば、鉄製の鍋を加熱する場合には均一な加熱を行うことが可能となり、アルミ製の鍋を加熱する場合には高周波電流を低減することが可能となる。 According to this aspect, uniform heating can be performed when an iron pan is heated, and high-frequency current can be reduced when an aluminum pan is heated.
図１は、実施の形態１に係る誘導加熱装置のブロック構成図である。FIG. 1 is a block configuration diagram of the induction heating apparatus according to the first embodiment. 図２は、実施の形態１に係る誘導加熱装置における、加熱コイルの構成、配置および接続を示すブロック構成図である。FIG. 2 is a block configuration diagram showing the configuration, arrangement, and connection of the heating coil in the induction heating apparatus according to the first embodiment. 図３Ａは、鉄系の鍋を加熱する場合における、スイッチング素子の駆動信号、および、加熱コイルに流れる電流の波形図である。FIG. 3A is a waveform diagram of a drive signal of a switching element and a current flowing through a heating coil when heating an iron-based pan. 図３Ｂは、鉄系の鍋を加熱する場合における、加熱コイルに流れる電流の向きを模式的に示す図である。FIG. 3B is a diagram schematically showing the direction of the current flowing through the heating coil when heating an iron-based pan. 図４Ａは、アルミ系の鍋を加熱する場合における、スイッチング素子の駆動信号、および、加熱コイルに流れる電流の波形図である。FIG. 4A is a waveform diagram of a drive signal of a switching element and a current flowing through a heating coil when an aluminum pan is heated. 図４Ｂは、アルミ系の鍋を加熱する場合における、加熱コイルに流れる電流の向きを模式的に示す図である。FIG. 4B is a diagram schematically showing the direction of the current flowing through the heating coil when heating an aluminum pan. 図５Ａは、一つまたは複数の加熱コイルの中心点からの距離と温度上昇比との関係を示す図である。FIG. 5A is a diagram showing the relationship between the distance from the center point of one or more heating coils and the temperature rise ratio. 図５Ｂは、一つのまたは複数の加熱コイルの形状および中心点を模式的に示す図である。FIG. 5B is a diagram schematically showing the shape and center point of one or a plurality of heating coils. 図６Ａは、四つの加熱コイルを搭載するシステムにおける、中心点からの距離と温度上昇比との関係を示す図である。FIG. 6A is a diagram showing the relationship between the distance from the center point and the temperature rise ratio in a system equipped with four heating coils. 図６Ｂは、加熱コイルの配置および中心点を模式的に示す図である。FIG. 6B is a diagram schematically showing the arrangement and center point of the heating coil. 図７は、実施の形態２に係る誘導加熱装置のブロック構成図である。FIG. 7 is a block diagram of the induction heating apparatus according to the second embodiment. 図８は、実施の形態２に係る誘導加熱装置における、加熱コイルの構成、配置および接続を示すブロック構成図である。FIG. 8 is a block configuration diagram showing the configuration, arrangement, and connection of the heating coil in the induction heating apparatus according to the second embodiment. 図９は、実施の形態３に係る誘導加熱装置のブロック構成図である。FIG. 9 is a block diagram of the induction heating apparatus according to the third embodiment. 図１０Ａは、実施の形態３に係る誘導加熱装置の動作を説明するための図である。FIG. 10A is a diagram for explaining the operation of the induction heating device according to the third embodiment. 図１０Ｂは、実施の形態３に係る誘導加熱装置の動作を説明するための図である。FIG. 10B is a diagram for explaining the operation of the induction heating apparatus according to Embodiment 3. 図１０Ｃは、実施の形態３に係る誘導加熱装置の動作を説明するための図である。FIG. 10C is a diagram for explaining the operation of the induction heating apparatus according to Embodiment 3. 図１０Ｄは、実施の形態３に係る誘導加熱装置の動作を説明するための図である。FIG. 10D is a diagram for explaining the operation of the induction heating device according to the third embodiment. 図１１Ａは、実施の形態３に係る誘導加熱装置の加熱コイルの配置および接続方法の一例を示す模式図である。FIG. 11A is a schematic diagram illustrating an example of the arrangement and connection method of the heating coils of the induction heating apparatus according to Embodiment 3. 図１１Ｂは、実施の形態３に係る誘導加熱装置の加熱コイルの配置および接続方法の一例を示す模式図である。FIG. 11B is a schematic diagram illustrating an example of the arrangement and connection method of the heating coils of the induction heating apparatus according to Embodiment 3. 図１２Ａは、各スイッチング素子に供給される駆動信号と、各加熱コイルに流れる電流とを示す波形図である。FIG. 12A is a waveform diagram showing a drive signal supplied to each switching element and a current flowing through each heating coil. 図１２Ｂは、各加熱コイルに流れる電流の向きを示す模式図である。FIG. 12B is a schematic diagram illustrating the direction of current flowing through each heating coil. 図１３Ａは、各スイッチング素子に供給される駆動信号と、各加熱コイルに流れる電流とを示す波形図である。FIG. 13A is a waveform diagram showing a drive signal supplied to each switching element and a current flowing through each heating coil. 図１３Ｂは、各加熱コイルに流れる電流の向きを示す模式図である。FIG. 13B is a schematic diagram illustrating the direction of current flowing through each heating coil. 図１４は、従来の誘導加熱装置のブロック構成図である。FIG. 14 is a block diagram of a conventional induction heating apparatus.
　本開示の第１の態様の誘導加熱装置は、トッププレートと複数の加熱コイルとインバータと制御部と判定部とを有する。誘導加熱装置は、トッププレートは、被加熱物を載置するように構成され。複数の加熱コイルは、トッププレートの下方に配置される。インバータは、複数の加熱コイルに電力を供給するように構成される。制御部は、インバータを制御するように構成される。判定部は、被加熱物が鉄系の負荷であるか、アルミ系の負荷であるかを判定するように構成される。制御部は、判定部による判定結果に応じて、複数の加熱コイルに流れる電流の向きを制御するように構成される。 The induction heating device according to the first aspect of the present disclosure includes a top plate, a plurality of heating coils, an inverter, a control unit, and a determination unit. In the induction heating apparatus, the top plate is configured to place an object to be heated. The plurality of heating coils are disposed below the top plate. The inverter is configured to supply power to the plurality of heating coils. The control unit is configured to control the inverter. The determination unit is configured to determine whether the object to be heated is an iron-based load or an aluminum-based load. The control unit is configured to control the direction of the current flowing through the plurality of heating coils according to the determination result by the determination unit.
　本開示の第２の態様の誘導加熱装置では、第１の態様に加えて、被加熱物が鉄系の負荷であると判定部が判定した場合、制御部が、複数の加熱コイルのうちの隣接する二つの加熱コイルに逆方向に電流を流すように構成される。 In the induction heating device according to the second aspect of the present disclosure, in addition to the first aspect, when the determination unit determines that the object to be heated is an iron-based load, the control unit includes a plurality of heating coils. It is comprised so that an electric current may be sent through two adjacent heating coils to a reverse direction.
　本開示の第３の態様の誘導加熱装置では、第１の態様に加えて、被加熱物がアルミ系の負荷であると判定部が判定した場合、制御部が、複数の加熱コイルのうちの隣接する二つの加熱コイルに同一方向に電流を流すように構成される。 In the induction heating apparatus according to the third aspect of the present disclosure, in addition to the first aspect, when the determination unit determines that the object to be heated is an aluminum-based load, the control unit includes a plurality of heating coils. It is comprised so that an electric current may be sent through the two adjacent heating coils in the same direction.
　本開示の第４の態様の誘導加熱装置では、第１の態様に加えて、隣接する二つの加熱コイル間の距離が４０ｍｍ以下に設定される。 In the induction heating device according to the fourth aspect of the present disclosure, in addition to the first aspect, the distance between two adjacent heating coils is set to 40 mm or less.
　本開示の第５の態様の誘導加熱装置では、第１の態様に加えて、複数の加熱コイルが四つの加熱コイルを含み、直列または並列に接続された二つの加熱コイルをそれぞれ含む二つの組がＸ字状に交差するように、四つの加熱コイルが配置される。 In the induction heating apparatus according to the fifth aspect of the present disclosure, in addition to the first aspect, the plurality of heating coils include four heating coils, each including two heating coils connected in series or in parallel. Are arranged so as to intersect in an X shape.
　本開示の第６の態様の誘導加熱装置は、第１の態様において、直流電源と、第１～第４のスイッチング素子と、第１～第４の共振コンデンサと、第１、第２の加熱コイルと、制御部とを有する。 According to a sixth aspect of the present disclosure, there is provided an induction heating apparatus according to the first aspect, wherein a DC power source, first to fourth switching elements, first to fourth resonance capacitors, and first and second heating elements are provided. A coil and a control unit;
　第１のスイッチング素子および第２のスイッチング素子は、互いに直列に接続されるとともに、直流電源に並列に接続される。 The first switching element and the second switching element are connected in series to each other and are connected in parallel to the DC power supply.
　第３のスイッチング素子および第４のスイッチング素子は、互いに直列に接続されるとともに、直流電源に並列に接続される。 The third switching element and the fourth switching element are connected in series to each other and are connected in parallel to the DC power supply.
　第１の加熱コイルの一端は、第１のスイッチング素子と第２のスイッチング素子との接続点に接続される。 One end of the first heating coil is connected to a connection point between the first switching element and the second switching element.
　第１の共振コンデンサの一端は、第１の加熱コイルの他端に接続される。 One end of the first resonance capacitor is connected to the other end of the first heating coil.
　第２の加熱コイルの一端は、第３のスイッチング素子と第４のスイッチング素子との接続点に接続される。 One end of the second heating coil is connected to a connection point between the third switching element and the fourth switching element.
　第４の共振コンデンサは、第２の加熱コイルの他端に接続された一端と、第１の共振コンデンサの他端に接続された他端とを有する。 The fourth resonance capacitor has one end connected to the other end of the second heating coil and the other end connected to the other end of the first resonance capacitor.
　第３の共振コンデンサは、第１の共振コンデンサと第４の共振コンデンサとの接続点に接続された一端と、直流電源の正極に接続された他端とを有する。 The third resonance capacitor has one end connected to the connection point between the first resonance capacitor and the fourth resonance capacitor, and the other end connected to the positive electrode of the DC power supply.
　第２の共振コンデンサは、第１の共振コンデンサと第４の共振コンデンサとの接続点に接続された一端と、直流電源の負極に接続された他端とを有する。 The second resonance capacitor has one end connected to the connection point between the first resonance capacitor and the fourth resonance capacitor, and the other end connected to the negative electrode of the DC power supply.
　制御部は、第１のスイッチング素子と第２のスイッチング素子とを交互にオンし、第３のスイッチング素子と第４のスイッチング素子とを交互にオンする。 The control unit turns on the first switching element and the second switching element alternately, and turns on the third switching element and the fourth switching element alternately.
　制御部は、被加熱物が非磁性材質である場合、第１のスイッチング素子と第３のスイッチング素子とを同時にオンし、第２のスイッチング素子と第４のスイッチング素子とを同時にオンする。 The control unit turns on the first switching element and the third switching element at the same time and turns on the second switching element and the fourth switching element at the same time when the object to be heated is a non-magnetic material.
　制御部は、被加熱物が磁性材質である場合、第１のスイッチング素子と第４のスイッチング素子とを同時にオンし、第２のスイッチング素子と第３のスイッチング素子とを同時にオンする。 The control unit turns on the first switching element and the fourth switching element simultaneously and turns on the second switching element and the third switching element simultaneously when the object to be heated is a magnetic material.
　以下、本開示の実施の形態について、図面を参照しながら説明する。 Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.
　（実施の形態１）
　図１は、実施の形態１に係る誘導加熱装置２０Ａのブロック構成図である。図１に示すように、誘導加熱装置２０Ａは、整流回路２とチョークコイル３とコンデンサ４とスイッチング素子５、６、９、１０と加熱コイル７ａ、７ｂ、１１ａ、１１ｂと共振コンデンサ８と制御部１４と電流検知部１５と電圧検知部１６、１７とを有する。 (Embodiment 1)
FIG. 1 is a block configuration diagram of induction heating apparatus 20A according to the first embodiment. As shown in FIG. 1, the induction heating device 20A includes a rectifier circuit 2, a choke coil 3, a capacitor 4, switching elements 5, 6, 9, and 10, heating coils 7a, 7b, 11a, and 11b, a resonant capacitor 8, and a control unit. 14, a current detection unit 15, and voltage detection units 16 and 17.
　整流回路２は、商用電源１からの交流電圧を整流するダイオードブリッジである。チョークコイル３の一端は、整流回路２の正側出力端に接続される。チョークコイル３の他端は、コンデンサ４の一端に接続される。コンデンサ４の他端は、整流回路２の負側出力端に接続される。チョークコイル３とコンデンサ４とは、フィルタ部を構成する。電流検知部１５は、コンデンサ４の他端と整流回路２の負側出力端との間に設けられる。 The rectifier circuit 2 is a diode bridge that rectifies the AC voltage from the commercial power source 1. One end of the choke coil 3 is connected to the positive output terminal of the rectifier circuit 2. The other end of the choke coil 3 is connected to one end of the capacitor 4. The other end of the capacitor 4 is connected to the negative output end of the rectifier circuit 2. The choke coil 3 and the capacitor 4 constitute a filter unit. The current detection unit 15 is provided between the other end of the capacitor 4 and the negative output end of the rectifier circuit 2.
　スイッチング素子５とスイッチング素子６とは、ＩＧＢＴ（Insulated Gate Bipolar Transistor）などで構成され、逆方向に接続されたダイオードを内蔵する。 The switching element 5 and the switching element 6 are composed of IGBTs (Insulated Gate Bipolar Transistors) or the like, and incorporate diodes connected in opposite directions.
　加熱コイル７ａ、７ｂと共振コンデンサ８とは直列に接続される。スイッチング素子５とスイッチング素子６との間の接続点Ａは、加熱コイル７ａの一端に接続される。加熱コイル７ａの他端は加熱コイル７ｂの一端に接続される。加熱コイル７ｂの他端は共振コンデンサ８の一端と接続される。共振コンデンサ８の他端は、スイッチング素子６のドレインに接続された接続点Ｂに接続される。 The heating coils 7a and 7b and the resonant capacitor 8 are connected in series. A connection point A between the switching element 5 and the switching element 6 is connected to one end of the heating coil 7a. The other end of the heating coil 7a is connected to one end of the heating coil 7b. The other end of the heating coil 7 b is connected to one end of the resonance capacitor 8. The other end of the resonant capacitor 8 is connected to a connection point B connected to the drain of the switching element 6.
　スイッチング素子５、６が、第１のインバータであるインバータ１８を構成する。インバータ１８は、フィルタ部により処理された電力を交流に変換し、その交流電力を加熱コイル７ａと加熱コイル７ｂとに供給する。 The switching elements 5 and 6 constitute an inverter 18 that is a first inverter. The inverter 18 converts the power processed by the filter unit into alternating current, and supplies the alternating current power to the heating coil 7a and the heating coil 7b.
　電圧検知部１６は、加熱コイル７ｂと共振コンデンサ８との間に設けられ、加熱コイル７ｂと共振コンデンサ８との接続点の電圧を検出する。 The voltage detector 16 is provided between the heating coil 7b and the resonance capacitor 8, and detects the voltage at the connection point between the heating coil 7b and the resonance capacitor 8.
　同様に、スイッチング素子９とスイッチング素子１０とは、ＩＧＢＴなどで構成され、逆方向に接続されたダイオードを内蔵する。 Similarly, the switching element 9 and the switching element 10 are composed of IGBTs or the like, and incorporate diodes connected in the reverse direction.
　加熱コイル１１ａ、１１ｂと共振コンデンサ１２とは直列に接続される。スイッチング素子９とスイッチング素子１０との間の接続点Ｃは、加熱コイル１１ａの一端に接続される。加熱コイル１１ａの他端は加熱コイル１１ｂの一端に接続される。加熱コイル１１ｂの他端は共振コンデンサ１２の一端と接続される。共振コンデンサ１２の他端は、スイッチング素子１０のドレインに接続された接続点Ｄに接続される。 The heating coils 11a and 11b and the resonance capacitor 12 are connected in series. A connection point C between the switching element 9 and the switching element 10 is connected to one end of the heating coil 11a. The other end of the heating coil 11a is connected to one end of the heating coil 11b. The other end of the heating coil 11 b is connected to one end of the resonance capacitor 12. The other end of the resonant capacitor 12 is connected to a connection point D connected to the drain of the switching element 10.
　スイッチング素子９、１０が、第２のインバータであるインバータ１９を構成する。インバータ１９は、フィルタ部により処理された電力を交流に変換し、その交流電力を加熱コイル１１ａと加熱コイル１１ｂとに供給する。 The switching elements 9 and 10 constitute an inverter 19 that is a second inverter. The inverter 19 converts the power processed by the filter unit into alternating current, and supplies the alternating current power to the heating coil 11a and the heating coil 11b.
　電圧検知部１７は、加熱コイル１１ｂと共振コンデンサ１２との間に設けられ、加熱コイル１１ｂと共振コンデンサ１２との接続点の電圧を検出する。 The voltage detector 17 is provided between the heating coil 11b and the resonance capacitor 12, and detects the voltage at the connection point between the heating coil 11b and the resonance capacitor 12.
　インバータ１９はインバータ１８に並列に接続される。インバータ１８とインバータ１９とは、整流回路２、チョークコイル３、コンデンサ４を共有する。 The inverter 19 is connected to the inverter 18 in parallel. The inverter 18 and the inverter 19 share the rectifier circuit 2, the choke coil 3, and the capacitor 4.
　絶縁体で耐熱セラミック製のトッププレート（図示せず）が、加熱コイル７ａ、７ｂ、１１ａ、１１ｂの上方に設けられる。被加熱物である鍋１３は、トッププレート上に載置される。 An insulating and heat-resistant ceramic top plate (not shown) is provided above the heating coils 7a, 7b, 11a, and 11b. The pan 13 that is an object to be heated is placed on the top plate.
　加熱コイル７ａ、７ｂ、１１ａ、１１ｂは、同一の形状、サイズ、巻き方向と、異なる中心とを有し、同一平面上に配置される（図２参照）。 The heating coils 7a, 7b, 11a, 11b have the same shape, size, winding direction and different centers, and are arranged on the same plane (see FIG. 2).
　制御部１４は、マイクロコンピュータで構成され、スイッチング素子５、６、９、１０を制御する。制御部１４は、鍋１３の材質を判定する判定部１４ａを含む。判定部１４ａは、電流検知部１５、電圧検知部１６、１７により検出された値に基づいて、鍋１３が鉄系またはアルミ系のいずれの材質で構成されるかを判定する。以下、判定部１４ａの詳細について説明する。 The control unit 14 is composed of a microcomputer and controls the switching elements 5, 6, 9, and 10. The control unit 14 includes a determination unit 14 a that determines the material of the pan 13. The determination unit 14a determines whether the pan 13 is made of iron or aluminum based on the values detected by the current detection unit 15 and the voltage detection units 16 and 17. Hereinafter, details of the determination unit 14a will be described.
　あらかじめ、制御部１４は、鉄系の材質の鍋またはアルミ系の材質の鍋がトッププレートに載置され、スイッチング素子５、９が所定期間オンされた場合における、電流検知部１５、電圧検知部１６、１７により測定された値を参考データとして記憶する。 In advance, the control unit 14 includes a current detection unit 15 and a voltage detection unit in a case where an iron-based pan or an aluminum-based pan is placed on the top plate and the switching elements 5 and 9 are turned on for a predetermined period. The values measured by 16, 17 are stored as reference data.
　鍋１３がトッププレート上に載置されると、加熱が開始されるまでに、制御部１４は、スイッチング素子５、９を所定期間オンし、電流検知部１５と電圧検知部１６、１７とにより測定された値を得る。 When the pan 13 is placed on the top plate, the control unit 14 turns on the switching elements 5 and 9 for a predetermined period until the heating is started, and the current detection unit 15 and the voltage detection units 16 and 17 Get the measured value.
　制御部１４は、実際の測定値を参考データと比較することにより、鍋１３の材質を判定する。具体的には、鉄系の鍋とアルミ系の鍋とでは、直列抵抗値と直列インダクタンス値とが異なる。鉄系の鍋の場合における電流値に対する電圧値は、アルミ系の鍋の場合のそれに比べて低い。このことを利用して、制御部１４は、鍋１３の材質を判定する。 The control unit 14 determines the material of the pan 13 by comparing the actual measurement value with the reference data. Specifically, the series resistance value and the series inductance value are different between the iron-based pan and the aluminum-based pan. The voltage value relative to the current value in the case of an iron-based pan is lower than that in the case of an aluminum-based pan. Using this, the control unit 14 determines the material of the pan 13.
　図２は、誘導加熱装置２０Ａにおける、加熱コイル７ａ、７ｂ、１１ａ、１１ｂの構成、配置および接続を示すブロック構成図である。 FIG. 2 is a block configuration diagram showing the configuration, arrangement, and connection of the heating coils 7a, 7b, 11a, and 11b in the induction heating device 20A.
　図２に示すように、加熱コイル７ａ、７ｂ、１１ａ、１１ｂは、外側から内側に向かって時計回りの巻き方向を有する。 As shown in FIG. 2, the heating coils 7a, 7b, 11a, and 11b have a clockwise winding direction from the outside toward the inside.
　加熱コイル７ａ、７ｂは、加熱コイル７ａの内側端が加熱コイル７ｂの外側端に接続されて直列に接続される。加熱コイル７ａの外側端は、接続点Ａに接続される。加熱コイル７ｂの内側端は、共振コンデンサ８に接続される。 The heating coils 7a and 7b are connected in series with the inner end of the heating coil 7a being connected to the outer end of the heating coil 7b. The outer end of the heating coil 7a is connected to the connection point A. The inner end of the heating coil 7 b is connected to the resonance capacitor 8.
　加熱コイル１１ａ、１１ｂは、加熱コイル１１ａの内側端が加熱コイル１１ｂの外側端に接続されて直列に接続される。加熱コイル１１ａの外側端は、接続点Ｃに接続される。加熱コイル１１ｂの内側端は、共振コンデンサ１２に接続される。 The heating coils 11a and 11b are connected in series with the inner end of the heating coil 11a being connected to the outer end of the heating coil 11b. The outer end of the heating coil 11a is connected to the connection point C. The inner end of the heating coil 11 b is connected to the resonance capacitor 12.
　直列に接続された加熱コイル７ａ、７ｂが、直列に接続された加熱コイル１１ａ、１１ｂとＸ字状に交差するように、加熱コイル７ａ、７ｂ、１１ａ、１１ｂが配置される。インバータ１８は、加熱コイル７ａ、７ｂを駆動し、インバータ１９は、加熱コイル１１ａ、１１ｂを駆動する。 The heating coils 7a, 7b, 11a, 11b are arranged so that the heating coils 7a, 7b connected in series intersect with the heating coils 11a, 11b connected in series in an X shape. The inverter 18 drives the heating coils 7a and 7b, and the inverter 19 drives the heating coils 11a and 11b.
　図３Ａは、鉄系の鍋を加熱する場合における、四つのスイッチング素子の駆動信号、および、四つの加熱コイルに流れる電流の波形図である。図３Ｂは、鉄系の鍋を加熱する場合における、四つの加熱コイルの各々に流れる電流の向きを模式的に示す図である。 FIG. 3A is a waveform diagram of drive signals of four switching elements and currents flowing through four heating coils when heating an iron-based pan. FIG. 3B is a diagram schematically showing the directions of currents flowing through each of the four heating coils when heating an iron-based pan.
　図３Ａに示すように、制御部１４は、スイッチング素子５、９を同じ駆動信号で駆動する。制御部１４は、スイッチング素子６、１０を、スイッチング素子５、９のための駆動信号とは異なる駆動信号で駆動する。 As shown in FIG. 3A, the control unit 14 drives the switching elements 5 and 9 with the same drive signal. The control unit 14 drives the switching elements 6 and 10 with a drive signal different from the drive signals for the switching elements 5 and 9.
　図４Ａは、アルミ系の鍋を加熱する場合における、四つのスイッチング素子の駆動信号、および、四つの加熱コイルに流れる電流の波形図である。図４Ｂは、アルミ系の鍋を加熱する場合における、四つの加熱コイルの各々に流れる電流の向きを模式的に示す図である。 FIG. 4A is a waveform diagram of drive signals of four switching elements and currents flowing through four heating coils when heating an aluminum pan. FIG. 4B is a diagram schematically showing the directions of currents flowing through each of the four heating coils when heating an aluminum pan.
　図４Ａに示すように、制御部１４は、スイッチング素子５、１０を同じ駆動信号で駆動する。制御部１４は、スイッチング素子６、９を、スイッチング素子５、１０のための駆動信号とは異なる駆動信号で駆動する。 As shown in FIG. 4A, the control unit 14 drives the switching elements 5 and 10 with the same drive signal. The control unit 14 drives the switching elements 6 and 9 with a drive signal different from the drive signals for the switching elements 5 and 10.
　上述のように、制御部１４はマイクロコンピュータで構成される。制御部１４はマイクロコンピュータに限られるものではない。しかしながら、プログラム可能なマイクロコンピュータを用いれば、処理内容を容易に変更可能であり、設計の自由度を高めることができる。 As described above, the control unit 14 is composed of a microcomputer. The control unit 14 is not limited to a microcomputer. However, if a programmable microcomputer is used, the processing contents can be easily changed, and the degree of design freedom can be increased.
　処理速度の向上のため、制御部１４を論理回路で構成することも可能である。制御部１４を物理的に一つまたは複数の素子で構成してもよい。制御部１４を複数の素子で構成する場合、制御部１４と判定部１４ａとを別々の素子で実施してもよい。この場合、これら複数の素子が一つの制御部に対応すると考えることができる。 In order to improve the processing speed, it is possible to configure the control unit 14 with a logic circuit. The control unit 14 may be physically composed of one or a plurality of elements. When the control unit 14 is configured by a plurality of elements, the control unit 14 and the determination unit 14a may be implemented by separate elements. In this case, it can be considered that these plural elements correspond to one control unit.
　以下、上記のように構成された誘導加熱装置の動作、作用について説明する。 Hereinafter, the operation and action of the induction heating apparatus configured as described above will be described.
　加熱コイル７ａ、７ｂ、１１ａ、１１ｂの上方のトッププレートに載置された鍋１３の加熱を開始する前に、制御部１４はスイッチング素子に駆動信号を所定期間供給する。その時の電流検知部１５および電圧検知部１６、１７の検出値をもとに、アルミ系の鍋であるか、鉄系の鍋であるかを判定部１４ａが判定する。 Before starting heating the pan 13 placed on the top plate above the heating coils 7a, 7b, 11a, 11b, the control unit 14 supplies a drive signal to the switching element for a predetermined period. Based on the detection values of the current detection unit 15 and the voltage detection units 16 and 17 at that time, the determination unit 14a determines whether the pan is an aluminum pan or an iron pan.
　ここで、アルミ系の鍋には、アルミ製の鍋だけでなく、銅製の鍋、アルミの割合が多い多層構造の鍋などが含まれる。鉄系の鍋とは、ホーロー製の鍋、磁性ステンレス製の鍋などを指す。 Here, aluminum pots include not only aluminum pots, but also copper pots, multi-layer pots with a high proportion of aluminum, and the like. Iron-based pots include enamel pots and magnetic stainless steel pots.
　鍋１３が鉄系の鍋と判定された場合、図３Ａに示すように、制御部１４は、スイッチング素子５、６、９、１０に駆動信号を供給する。 When it is determined that the pan 13 is an iron pan, the control unit 14 supplies a drive signal to the switching elements 5, 6, 9, and 10 as illustrated in FIG. 3A.
　この場合、加熱コイル７ａ、７ｂに流れる電流は、加熱コイル１１ａ、１１ｂに流れる電流と同位相となる。すなわち、接続点Ａから加熱コイル７ａ、７ｂを通って接続点Ｂに電流が流れる時には、接続点Ｃから加熱コイル１１ａ、１１ｂを通って接続点Ｄに電流が流れる（図１、図２参照）。 In this case, the current flowing through the heating coils 7a and 7b is in phase with the current flowing through the heating coils 11a and 11b. That is, when a current flows from the connection point A through the heating coils 7a and 7b to the connection point B, a current flows from the connection point C through the heating coils 11a and 11b to the connection point D (see FIGS. 1 and 2). .
　図３Ｂに示すように、隣接する二つの加熱コイル、すなわち、加熱コイル７ａおよび１１ａ、加熱コイル１１ａおよび７ｂ、加熱コイル７ｂおよび１１ｂ、加熱コイル１１ｂおよび７ａの間の領域において、互いに逆方向に電流が流れる。 As shown in FIG. 3B, in the adjacent two heating coils, that is, between the heating coils 7a and 11a, the heating coils 11a and 7b, the heating coils 7b and 11b, and the heating coils 11b and 7a, Flows.
　その結果、隣接する二つの加熱コイルの間の領域において磁界が打ち消し合って、局所的な過度の加熱を防止することにより、鍋１３を均一に加熱することができる。 As a result, the magnetic field cancels out in a region between two adjacent heating coils, and local excessive heating is prevented, whereby the pan 13 can be heated uniformly.
　鍋１３がアルミ系の鍋と判定された場合、図４Ａに示すように、制御部１４は、スイッチング素子５、６、９、１０に駆動信号を供給する。 When it is determined that the pan 13 is an aluminum pan, the control unit 14 supplies a drive signal to the switching elements 5, 6, 9, and 10 as illustrated in FIG. 4A.
　この場合、加熱コイル７ａ、７ｂに流れる電流は、加熱コイル１１ａ、１１ｂに流れる電流と逆位相となる。すなわち、接続点Ａから加熱コイル７ａ、７ｂを通って接続点Ｂに電流が流れる時には、接続点Ｄから加熱コイル１１ｂ、１１ａを通って接続点Ｃに電流が流れる（図１、図２参照）。 In this case, the current flowing through the heating coils 7a and 7b is in opposite phase to the current flowing through the heating coils 11a and 11b. That is, when a current flows from the connection point A through the heating coils 7a and 7b to the connection point B, a current flows from the connection point D through the heating coils 11b and 11a to the connection point C (see FIGS. 1 and 2). .
　図４Ｂに示すように、隣接する二つの加熱コイル、すなわち、加熱コイル７ａおよび１１ａ、加熱コイル１１ａおよび７ｂ、加熱コイル７ｂおよび１１ｂ、加熱コイル１１ｂおよび７ａの間の領域において、同一方向に電流が流れる。 As shown in FIG. 4B, current flows in the same direction in two adjacent heating coils, namely, heating coils 7a and 11a, heating coils 11a and 7b, heating coils 7b and 11b, and heating coils 11b and 7a. Flowing.
　その結果、隣接する二つの加熱コイルの間の領域において磁界が互いに強め合って、加熱コイルと鍋１３との磁気結合が改善される。加熱コイルから見た鍋１３を含む負荷の抵抗値は増大し、固有抵抗値が低いアルミ系の鍋でも、小さな電流で十分に加熱することが可能となる。 As a result, the magnetic fields intensify each other in the region between the two adjacent heating coils, and the magnetic coupling between the heating coil and the pan 13 is improved. The resistance value of the load including the pan 13 as viewed from the heating coil increases, and even an aluminum pan having a low specific resistance value can be sufficiently heated with a small current.
　この場合、隣接する二つの加熱コイルの間の領域において磁界が互いに強め合うため、局所的に過度の加熱が生じる。しかし、アルミ系の鍋の場合、熱伝導率が鉄系の鍋より高く、鉄系の鍋の場合ほど加熱分布に関して大きな問題が生じない。 In this case, since the magnetic fields intensify each other in the region between two adjacent heating coils, excessive heating occurs locally. However, in the case of an aluminum pan, the thermal conductivity is higher than that of an iron pan, and the heating distribution is not as great as in the case of an iron pan.
　図５Ａは、一つまたは複数の加熱コイルの中心点からの距離と温度上昇比との関係を示す。図５Ｂは、一つのまたは複数の加熱コイルの形状および中心点を模式的に示す。以下、一つまたは複数の加熱コイルの中心点を単に中心点という。 FIG. 5A shows the relationship between the distance from the center point of one or more heating coils and the temperature rise ratio. FIG. 5B schematically shows the shape and center point of one or more heating coils. Hereinafter, the center point of one or a plurality of heating coils is simply referred to as a center point.
　図５Ａにおいて、横軸は、中心点からの距離を示す。縦軸は、温度上昇値の最大値に対する、中心点から横軸に示す距離だけ離れた地点における温度上昇値の割合を示す。 In FIG. 5A, the horizontal axis indicates the distance from the center point. The vertical axis represents the ratio of the temperature rise value at a point away from the center point by the distance indicated by the horizontal axis with respect to the maximum value of the temperature rise value.
　以下は、図５Ａに示された結果を得るために使用された実験システムの概要である（図５Ｂ参照）。いずれの場合においても、ホーロー製の鍋が使用される。 The following is an overview of the experimental system used to obtain the results shown in FIG. 5A (see FIG. 5B). In either case, enamel pans are used.
　（５－１）一つの加熱コイルが設けられる場合、外径が１９０ｍｍの加熱コイルが使用される。この場合、中心点は巻線の中心である。 (5-1) When one heating coil is provided, a heating coil having an outer diameter of 190 mm is used. In this case, the center point is the center of the winding.
　（５－２）二つの加熱コイルが設けられる場合、長軸が１９０ｍｍおよび短軸が７５ｍｍの二つの楕円形状の加熱コイルが使用される。二つの加熱コイルの間の距離は２０ｍｍに設定される。中心点は、二つの加熱コイルの各々の中心を結ぶ線分の中点である。この場合のシステムは、二つの加熱コイルに互いに逆方向に電流が流れるように構成される。 (5-2) When two heating coils are provided, two elliptical heating coils having a major axis of 190 mm and a minor axis of 75 mm are used. The distance between the two heating coils is set to 20 mm. The center point is the midpoint of the line segment connecting the centers of the two heating coils. The system in this case is configured such that current flows through the two heating coils in opposite directions.
　（５－３）四つの加熱コイルが設けられる場合、外径が７６ｍｍの四つの加熱コイルが使用される。隣接する二つの加熱コイルの間の距離は２０ｍｍに設定される。この場合のシステムは、上述のように、隣接する二つの加熱コイルに互いに逆方向に電流が流れるように構成される。 (5-3) When four heating coils are provided, four heating coils having an outer diameter of 76 mm are used. The distance between two adjacent heating coils is set to 20 mm. As described above, the system in this case is configured such that currents flow in opposite directions to two adjacent heating coils.
　図５Ａに示すように、一つの加熱コイルが搭載される場合、中心点の付近および中心点から離れた地点において、温度上昇比が低下する。二つまたは四つの加熱コイルが搭載される場合、一つの加熱コイルの場合より温度上昇比の変動が小さい。 As shown in FIG. 5A, when one heating coil is mounted, the temperature increase ratio decreases near the center point and at a point away from the center point. When two or four heating coils are mounted, the variation in temperature rise ratio is smaller than in the case of one heating coil.
　この結果は、隣接する二つの加熱コイルに互いに逆方向に電流を流すことにより、鍋１３が均一に加熱されることを示す。 This result shows that the pan 13 is heated uniformly by flowing currents in the opposite directions to the two adjacent heating coils.
　図６Ａは、四つの加熱コイルを搭載するシステムにおける、中心点からの距離と温度上昇比との関係を示す。図６Ｂは、四つの加熱コイルの配置および中心点を模式的に示す。 FIG. 6A shows the relationship between the distance from the center point and the temperature rise ratio in a system equipped with four heating coils. FIG. 6B schematically shows the arrangement and center point of the four heating coils.
　以下は、図６Ａに示された結果を得るために使用された実験システムの概要である（図６Ｂ参照）。いずれの場合においても、ホーロー製の鍋が使用される。 The following is an overview of the experimental system used to obtain the results shown in FIG. 6A (see FIG. 6B). In either case, enamel pans are used.
　（６－１）隣接する二つの加熱コイルの間の距離が６０ｍｍに設定される。 (6-1) The distance between two adjacent heating coils is set to 60 mm.
　（６－２）隣接する二つの加熱コイルの間の距離が４０ｍｍに設定される。 (6-2) The distance between two adjacent heating coils is set to 40 mm.
　（６－３）隣接する二つの加熱コイルの間の距離が２０ｍｍに設定される。 (6-3) The distance between two adjacent heating coils is set to 20 mm.
　これらのシステムには、内径が２５ｍｍ、外径が７６ｍｍの四つの加熱コイルが設けられる。これらのシステムは、上述のように、隣接する二つの加熱コイルに互いに逆方向に電流が流れるように構成される。 These systems are provided with four heating coils with an inner diameter of 25 mm and an outer diameter of 76 mm. As described above, these systems are configured such that currents flow in opposite directions to two adjacent heating coils.
　図６Ａに示すように、いずれの場合も、中心点付近の地点および中心点から離れた地点において、温度上昇比が低下する。しかし、隣接する二つの加熱コイルの間の距離が２０ｍｍの場合、三つの場合のうち、温度上昇比の低下が最も少ない。 As shown in FIG. 6A, in any case, the temperature increase ratio decreases at a point near the center point and a point away from the center point. However, when the distance between two adjacent heating coils is 20 mm, the decrease in the temperature increase ratio is the smallest among the three cases.
　隣接する二つの加熱コイルの間の距離が４０ｍｍの場合、隣接する二つの加熱コイルの間の距離が２０ｍｍの場合に比べて、温度上昇比は２０％以上低下しない。 When the distance between two adjacent heating coils is 40 mm, the temperature increase ratio does not decrease by more than 20% compared to the case where the distance between two adjacent heating coils is 20 mm.
　隣接する二つの加熱コイルの間の距離が６０ｍｍの場合、隣接する二つの加熱コイルの間の距離が２０ｍｍの場合に比べて、温度上昇比は２０％以上低下する。 When the distance between two adjacent heating coils is 60 mm, the temperature increase ratio decreases by 20% or more compared to the case where the distance between two adjacent heating coils is 20 mm.
　本実施の形態によれば、鉄系の鍋に対しては均一に加熱することができ、アルミ系の鍋に対しては効率的に加熱することができる。 According to the present embodiment, it is possible to uniformly heat the iron-based pan and efficiently heat the aluminum-based pan.
　本実施の形態では、誘導加熱装置２０Ａは四つの加熱コイルを有する。しかしながら、加熱コイルの個数はこれに限定されない。鉄系の鍋を加熱する場合は、隣接する二つの加熱コイルに関して互いに逆方向に電流が流れるように、誘導加熱装置を構成しさえすればいい。アルミ系の鍋を加熱する場合は、隣接する二つの加熱コイルに関して同一方向に電流が流れるように、誘導加熱装置を構成しさえすればいい。 In the present embodiment, the induction heating device 20A has four heating coils. However, the number of heating coils is not limited to this. When heating an iron-based pan, it is only necessary to configure the induction heating device so that currents flow in opposite directions with respect to two adjacent heating coils. When heating an aluminum pan, it is only necessary to configure the induction heating device so that current flows in the same direction with respect to two adjacent heating coils.
　（実施の形態２）
　以下、実施の形態２について説明する。以下の説明において、実施の形態１と同一または相当部分には同一符号を付し、重複する説明を省略する。 (Embodiment 2)
The second embodiment will be described below. In the following description, the same or corresponding parts as those in the first embodiment are denoted by the same reference numerals, and redundant description is omitted.
　図７は、本実施の形態に係る誘導加熱装置２０Ｂのブロック構成図である。図８は、誘導加熱装置２０Ｂにおける、加熱コイル７ａ、７ｂ、１１ａ、１１ｂの構成、配置および接続を示すブロック構成図である。 FIG. 7 is a block configuration diagram of the induction heating apparatus 20B according to the present embodiment. FIG. 8 is a block configuration diagram showing the configuration, arrangement, and connection of the heating coils 7a, 7b, 11a, and 11b in the induction heating device 20B.
　本実施の形態では、加熱コイル７ａ、７ｂは並列に接続され、加熱コイル１１ａ、１１ｂは並列に接続される。並列に接続された加熱コイル７ａ、７ｂは、共振コンデンサ８と直列に接続される。並列に接続された加熱コイル１１ａ、１１ｂは、共振コンデンサ１２と直列に接続される。それ以外の構成は、実施の形態１と同じである。 In this embodiment, the heating coils 7a and 7b are connected in parallel, and the heating coils 11a and 11b are connected in parallel. The heating coils 7 a and 7 b connected in parallel are connected in series with the resonance capacitor 8. The heating coils 11 a and 11 b connected in parallel are connected in series with the resonance capacitor 12. Other configurations are the same as those of the first embodiment.
　並列に接続された加熱コイル７ａ、７ｂが、並列に接続された加熱コイル１１ａ、１１ｂとＸ字状に交差するように、加熱コイル７ａ、７ｂ、１１ａ、１１ｂが配置される。 The heating coils 7a, 7b, 11a, 11b are arranged so that the heating coils 7a, 7b connected in parallel intersect with the heating coils 11a, 11b connected in parallel in an X shape.
　実施の形態１と同様に、誘導加熱装置２０Ｂにおいて、鉄系の鍋を加熱する場合は、隣接する二つの加熱コイルに関して互いに逆方向に電流が流れる。アルミ系の鍋を加熱する場合は、隣接する二つの加熱コイルに関して同一方向に電流が流れる。 As in the first embodiment, in the induction heating device 20B, when heating an iron pan, currents flow in opposite directions with respect to two adjacent heating coils. When heating an aluminum pan, current flows in the same direction with respect to two adjacent heating coils.
　本実施の形態によれば、鉄系の鍋に対しては均一に加熱することができ、アルミ系の鍋に対しては効率的に加熱することができる。 According to the present embodiment, it is possible to uniformly heat the iron-based pan and efficiently heat the aluminum-based pan.
　（実施の形態３）
　以下、実施の形態３について説明する。図９は、本実施の形態に係る誘導加熱装置２０Ｃのブロック構成図である。図９に示すように、誘導加熱装置２０Ｃは、直流電源３１、共振コンデンサ３２、３３、３８、３９、スイッチング素子３５、３６、４１、４２、加熱コイル３４、４０、制御部３７を備える。 (Embodiment 3)
Hereinafter, the third embodiment will be described. FIG. 9 is a block configuration diagram of induction heating device 20C according to the present embodiment. As shown in FIG. 9, the induction heating device 20 </ b> C includes a DC power supply 31, resonant capacitors 32, 33, 38, 39, switching elements 35, 36, 41, 42, heating coils 34, 40, and a control unit 37.
　本実施の形態において、加熱コイル３４、４０は、第１、第２の加熱コイルにそれぞれ相当する。スイッチング素子３５、３６、４１、４２は、第１、第２、第３、第４のスイッチング素子にそれぞれ相当する。共振コンデンサ３２、３３、３８、３９は、第１、第２、第３、第４の共振コンデンサにそれぞれ相当する。 In the present embodiment, the heating coils 34 and 40 correspond to first and second heating coils, respectively. The switching elements 35, 36, 41, and 42 correspond to first, second, third, and fourth switching elements, respectively. The resonant capacitors 32, 33, 38, and 39 correspond to the first, second, third, and fourth resonant capacitors, respectively.
　スイッチング素子３５、３６、４１、４２は、ＩＧＢＴなどで構成され、逆方向に接続されダイオードを内蔵する。 Switching elements 35, 36, 41, and 42 are formed of IGBTs or the like, and are connected in the reverse direction and incorporate diodes.
　スイッチング素子３５は、スイッチング素子３６と直列に接続される。スイッチング素子３５、３６は直流電源３１に並列に接続される。具体的には、スイッチング素子３５のエミッタはスイッチング素子３６のコレクタに接続される。スイッチング素子３５のコレクタは直流電源３１の正極に接続される。スイッチング素子３６エミッタは直流電源３１の負極に接続される。 The switching element 35 is connected in series with the switching element 36. The switching elements 35 and 36 are connected to the DC power supply 31 in parallel. Specifically, the emitter of the switching element 35 is connected to the collector of the switching element 36. The collector of the switching element 35 is connected to the positive electrode of the DC power supply 31. The switching element 36 emitter is connected to the negative electrode of the DC power supply 31.
　スイッチング素子４１は、スイッチング素子４２と直列に接続される。スイッチング素子４１、４２は直流電源３１に並列に接続される。具体的には、スイッチング素子４１のエミッタはスイッチング素子４２のコレクタに接続される。スイッチング素子４１のコレクタは直流電源３１の正極に接続される。スイッチング素子４２のエミッタは直流電源３１の負極に接続される。 The switching element 41 is connected in series with the switching element 42. The switching elements 41 and 42 are connected to the DC power supply 31 in parallel. Specifically, the emitter of the switching element 41 is connected to the collector of the switching element 42. The collector of the switching element 41 is connected to the positive electrode of the DC power supply 31. The emitter of the switching element 42 is connected to the negative electrode of the DC power supply 31.
　本実施の形態では、スイッチング素子３５、３６が、第１のインバータであるインバータ４５を構成する。スイッチング素子４１、４２が、第２のインバータであるインバータ４６を構成する。 In the present embodiment, the switching elements 35 and 36 constitute an inverter 45 that is a first inverter. The switching elements 41 and 42 constitute an inverter 46 that is a second inverter.
　加熱コイル３４の一端は、スイッチング素子３５、３６の接続点（接続点Ｅ）に接続される。共振コンデンサ３２の一端は、加熱コイル３４の他端に接続される。 One end of the heating coil 34 is connected to the connection point (connection point E) of the switching elements 35 and 36. One end of the resonance capacitor 32 is connected to the other end of the heating coil 34.
　加熱コイル４０の一端は、スイッチング素子４１、４２の接続点（接続点Ｇ）に接続される。共振コンデンサ３９は、加熱コイル４０の他端に接続された一端と、共振コンデンサ３２の他端に接続された他端とを有する。 One end of the heating coil 40 is connected to a connection point (connection point G) of the switching elements 41 and 42. The resonant capacitor 39 has one end connected to the other end of the heating coil 40 and the other end connected to the other end of the resonant capacitor 32.
　共振コンデンサ３８は、共振コンデンサ３２、３９の接続点（接続点Ｆ）に接続された一端と、直流電源３１の正極に接続された他端とを有する。共振コンデンサ３３は、共振コンデンサ３２、３９の接続点（接続点Ｆ）に接続された一端と、直流電源３１の負極に接続された他端とを有する。 The resonance capacitor 38 has one end connected to the connection point (connection point F) of the resonance capacitors 32 and 39 and the other end connected to the positive electrode of the DC power supply 31. The resonance capacitor 33 has one end connected to the connection point (connection point F) of the resonance capacitors 32 and 39 and the other end connected to the negative electrode of the DC power supply 31.
　電流検知部４３は、直流電源３１の負極に接続され、誘導加熱装置２０Ｃに流れる電流を検知する。電圧検知部４４は、接続点Ｆに接続され、接続点Ｆにおける電圧を検知する。 The current detector 43 is connected to the negative electrode of the DC power supply 31 and detects the current flowing through the induction heating device 20C. The voltage detection unit 44 is connected to the connection point F and detects the voltage at the connection point F.
　制御部３７は、インバータ４５に含まれるスイッチング素子３５、３６と、インバータ４６に含まれるスイッチング素子４１、４２とを制御する。制御部３７は、被加熱物である鍋の材質を判定する判定部３７ａを有する。 The control unit 37 controls the switching elements 35 and 36 included in the inverter 45 and the switching elements 41 and 42 included in the inverter 46. The control part 37 has the determination part 37a which determines the material of the pan which is a to-be-heated material.
　判定部３７ａは、電流検知部４３、電圧検知部４４により検出された値に基づいて、鍋の材質が磁性材質か非磁性材質かを判定する。判定部３７ａの判定方法は、上述の判定部１４ａと同じであり、詳細な説明は省略する。 The determination unit 37a determines whether the material of the pan is a magnetic material or a non-magnetic material based on the values detected by the current detection unit 43 and the voltage detection unit 44. The determination method of the determination unit 37a is the same as that of the determination unit 14a described above, and detailed description thereof is omitted.
　鍋が非磁性材質である場合、制御部３７は、スイッチング素子３５、３６を交互にオンし、スイッチング素子４１、４２を交互にオンする。それとともに、制御部３７は、スイッチング素子３５、４１を同時にオンし、スイッチング素子３６、４２を同時にオンする。 When the pan is made of a nonmagnetic material, the controller 37 turns on the switching elements 35 and 36 alternately and turns on the switching elements 41 and 42 alternately. At the same time, the control unit 37 turns on the switching elements 35 and 41 at the same time, and turns on the switching elements 36 and 42 at the same time.
　鍋が磁性材質である場合、制御部３７は、スイッチング素子３５、３６を交互にオンし、スイッチング素子４１、４２を交互にオンする。それとともに、制御部３７は、スイッチング素子３５、４２を同時にオンし、スイッチング素子３６、４１を同時にオンする。 When the pan is made of a magnetic material, the control unit 37 turns on the switching elements 35 and 36 alternately and turns on the switching elements 41 and 42 alternately. At the same time, the control unit 37 turns on the switching elements 35 and 42 simultaneously and turns on the switching elements 36 and 41 simultaneously.
　絶縁体で耐熱セラミック製のトッププレート（図示せず）が、加熱コイル３４、４０の上方に設けられる。鍋（図示せず）はトッププレート上に載置される。加熱コイル３４、４０は、同一の形状、サイズ、巻き方向を有し、同一平面上に隣り合うように配置される。 An insulating and heat-resistant ceramic top plate (not shown) is provided above the heating coils 34 and 40. A pan (not shown) is placed on the top plate. The heating coils 34 and 40 have the same shape, size and winding direction, and are arranged adjacent to each other on the same plane.
　加熱コイル３４、４０が同一の鍋を加熱する場合、制御部３７は、スイッチング素子３５、３６、４１、４２のための導通パターンを変更することで、加熱コイル３４、４０に流れる電流の向きを変えることができる。 When the heating coils 34 and 40 heat the same pan, the control unit 37 changes the conduction pattern for the switching elements 35, 36, 41 and 42, thereby changing the direction of the current flowing through the heating coils 34 and 40. Can be changed.
　すなわち、制御部３７は、加熱コイル３４、４０から発生する磁界を強め合う、または、打ち消し合う方向に、加熱コイル３４、４０に電流を流すことができる。このため、高効率な加熱や均一加熱を実現することができる。 That is, the control unit 37 can flow current through the heating coils 34 and 40 in a direction in which the magnetic fields generated from the heating coils 34 and 40 are strengthened or cancel each other. For this reason, highly efficient heating and uniform heating can be realized.
　共振コンデンサ３３、３８の容量を、共振コンデンサ３２、３９の容量に比べて、十分小さく設定すると、導通パターンの変更により、電流が流れる経路上の共振コンデンサの合成容量を変更することができる。 When the capacitance of the resonance capacitors 33 and 38 is set sufficiently smaller than the capacitance of the resonance capacitors 32 and 39, the combined capacitance of the resonance capacitors on the path through which the current flows can be changed by changing the conduction pattern.
　図１０Ａ～図１０Ｄは、誘導加熱装置２０Ｃの動作を説明するための図である。 10A to 10D are diagrams for explaining the operation of the induction heating device 20C.
　まず、鍋が非磁性材質である場合について説明する。図１０Ａに示すように、スイッチング素子３５がオンされ、スイッチング素子３６がオフされると、直流電源３１と共振コンデンサ３２、３３と加熱コイル３４とスイッチング素子３５とを含む電流経路が構成される。 First, the case where the pan is made of a non-magnetic material will be described. As shown in FIG. 10A, when the switching element 35 is turned on and the switching element 36 is turned off, a current path including the DC power supply 31, the resonant capacitors 32 and 33, the heating coil 34, and the switching element 35 is formed.
　スイッチング素子４１がオンされ、スイッチング素子４２がオフされると、共振コンデンサ３８、３９と加熱コイル４０とスイッチング素子４１とを含む電流経路が構成される。これらの電流経路には、図１０Ａの矢印に示す電流が流れる。 When the switching element 41 is turned on and the switching element 42 is turned off, a current path including the resonant capacitors 38 and 39, the heating coil 40, and the switching element 41 is formed. A current indicated by an arrow in FIG. 10A flows through these current paths.
　すなわち、図１０Ａに示すように電流が流れる状態において、加熱コイル３４が含まれる電流経路は、共振コンデンサ３２、３３の合成容量を有する。加熱コイル４０が含まれる電流経路は、共振コンデンサ３８、３９の合成容量を有する。 That is, as shown in FIG. 10A, in a state where current flows, the current path including the heating coil 34 has a combined capacity of the resonance capacitors 32 and 33. The current path including the heating coil 40 has a combined capacity of the resonance capacitors 38 and 39.
　所定時間の経過後、全てのスイッチング素子がオフされる。その後、スイッチング素子３６、４２が同時にオンされると、図１０Ｂに示すように、直流電源３１と共振コンデンサ３２、３８と加熱コイル３４とスイッチング素子３６とを含む電流経路が構成される。共振コンデンサ３３、３９と加熱コイル４０とスイッチング素子４２とを含む電流経路が構成される。これらの電流経路には、図１０Ｂの矢印に示す電流が流れる。 ∙ After a predetermined time has elapsed, all switching elements are turned off. Thereafter, when the switching elements 36 and 42 are simultaneously turned on, a current path including the DC power supply 31, the resonant capacitors 32 and 38, the heating coil 34, and the switching element 36 is formed as shown in FIG. 10B. A current path including the resonant capacitors 33 and 39, the heating coil 40, and the switching element 42 is formed. The current shown by the arrow in FIG. 10B flows through these current paths.
　すなわち、図１０Ｂに示すように電流が流れる状態において、加熱コイル３４が含まれる電流経路は、共振コンデンサ３２、３８の合成容量を有する。加熱コイル４０が含まれる電流経路は、共振コンデンサ３３、３９の合成容量を有する。 That is, as shown in FIG. 10B, in a state where current flows, the current path including the heating coil 34 has the combined capacity of the resonance capacitors 32 and 38. The current path including the heating coil 40 has a combined capacity of the resonance capacitors 33 and 39.
　所定時間の経過後、全てのスイッチング素子がオフされる。その後、図１０Ａに示すように、スイッチング素子３５、４１が再びオンされる。 ∙ After a predetermined time has elapsed, all switching elements are turned off. Thereafter, as shown in FIG. 10A, the switching elements 35 and 41 are turned on again.
　次に、鍋が磁性材質である場合について説明する。図１０Ｃに示すように、スイッチング素子３５、４２がオンされ、スイッチング素子３６、４２がオフされると、直流電源３１と共振コンデンサ３２、３９と加熱コイル３４、４０とスイッチング素子３５、４２とを含む電流経路が構成される。この電流経路には、図１０Ｃの矢印に示す電流が流れる。 Next, the case where the pan is made of a magnetic material will be described. As shown in FIG. 10C, when the switching elements 35 and 42 are turned on and the switching elements 36 and 42 are turned off, the DC power supply 31, the resonant capacitors 32 and 39, the heating coils 34 and 40, and the switching elements 35 and 42 are connected. Including a current path. A current indicated by an arrow in FIG. 10C flows through this current path.
　すなわち、図１０Ｃに示すように電流が流れる状態において、この電流経路は、共振コンデンサ３２、３９の合成容量を有する。 That is, in a state where a current flows as shown in FIG. 10C, this current path has a combined capacity of the resonance capacitors 32 and 39.
　所定時間の経過後、全てのスイッチング素子がオフされる。その後、スイッチング素子３６、４１が同時にオンされると、図１０Ｄに示すように、直流電源３１と共振コンデンサ３２、３９と加熱コイル３４、４０とスイッチング素子３６、４１とを含む電流経路が構成される。この電流経路には、図１０Ｄの矢印に示す電流が流れる。 ∙ After a predetermined time has elapsed, all switching elements are turned off. Thereafter, when the switching elements 36 and 41 are simultaneously turned on, as shown in FIG. 10D, a current path including the DC power supply 31, the resonant capacitors 32 and 39, the heating coils 34 and 40, and the switching elements 36 and 41 is formed. The A current indicated by an arrow in FIG. 10D flows through this current path.
　すなわち、図１０Ｄに示すように電流が流れる状態において、この電流経路は、共振コンデンサ３２、３９の合成容量を有する。 That is, in a state where a current flows as shown in FIG. 10D, this current path has a combined capacity of the resonance capacitors 32 and 39.
　所定時間の経過後、全てのスイッチング素子がオフされる。その後、図１０Ｃに示すように、スイッチング素子３５、４２が再びオンされる。 ∙ After a predetermined time has elapsed, all switching elements are turned off. Thereafter, as shown in FIG. 10C, the switching elements 35 and 42 are turned on again.
　本実施の形態では、共振コンデンサ３２、３９の容量が、共振コンデンサ３３、３８の容量に比べて十分大きく設定される。これにより、鍋が磁性材質で構成されるか否かに応じて、共振コンデンサの組合せを変更することで、共振コンデンサの合成容量を変更することができる。 In the present embodiment, the capacitances of the resonance capacitors 32 and 39 are set sufficiently larger than the capacitances of the resonance capacitors 33 and 38. Accordingly, the combined capacity of the resonance capacitors can be changed by changing the combination of the resonance capacitors depending on whether the pan is made of a magnetic material or not.
　図１０Ａ、図１０Ｂに示す、非磁性材質の鍋を加熱する場合の共振コンデンサの合成容量は、図１０Ｃ、図１０Ｄに示す、磁性材質の鍋を加熱する場合のそれより小さい。 10A and 10B, the combined capacity of the resonant capacitors when heating a nonmagnetic pot is smaller than that when heating a magnetic pot shown in FIGS. 10C and 10D.
　高周波の電流で加熱するためには、非磁性材質の鍋を加熱する場合の共振コンデンサの合成容量は、磁性材質の鍋を加熱する場合より小さい方がよい。一方、低周波の電流で加熱するためには、磁性材質の鍋を加熱する場合の共振コンデンサの合成容量は、非磁性材質の鍋を加熱する場合より大きいほうがよい。 In order to heat with a high frequency current, the combined capacity of the resonant capacitor when heating a non-magnetic pot is smaller than when heating a magnetic pot. On the other hand, in order to heat with a low frequency current, the combined capacity of the resonant capacitors when heating a magnetic pot is better than when heating a nonmagnetic pot.
　図１１Ａ、１１Ｂは、誘導加熱装置２０Ｃにおける、加熱コイルの配置および接続を示す模式図である。図１１Ａに示す例では、加熱コイル３４、加熱コイル４０はいずれも、一つの加熱コイルで構成される。 11A and 11B are schematic diagrams showing the arrangement and connection of heating coils in the induction heating apparatus 20C. In the example shown in FIG. 11A, both the heating coil 34 and the heating coil 40 are configured by one heating coil.
　図１１Ａに示すように、加熱コイル３４、４０は、外側から内側に向かって時計回りの巻き方向を有し、互いに隣接して配置される。加熱コイル３４の外側端は接続点Ｅに接続される。加熱コイル３４の内側端は共振コンデンサ３２に接続される（図９参照）。 As shown in FIG. 11A, the heating coils 34 and 40 have a clockwise winding direction from the outside to the inside, and are arranged adjacent to each other. The outer end of the heating coil 34 is connected to the connection point E. The inner end of the heating coil 34 is connected to the resonance capacitor 32 (see FIG. 9).
　図１１Ｂに示す例では、加熱コイル３４、４０はいずれも、二つの加熱コイルの直列体で構成される。これら四つの加熱コイルは、外側から内側に向かって時計回りの巻き方向を有する。 In the example shown in FIG. 11B, each of the heating coils 34 and 40 is composed of a series body of two heating coils. These four heating coils have a clockwise winding direction from the outside to the inside.
　加熱コイル３４を構成する二つの加熱コイルは、一方の加熱コイルの内側端が他方の加熱コイルの外側端に接続されて直列に接続される。一方の加熱コイルの外側端は接続点Ｅに接続される。他方の加熱コイルの内側端は共振コンデンサ３２に接続される。 The two heating coils constituting the heating coil 34 are connected in series with the inner end of one heating coil connected to the outer end of the other heating coil. The outer end of one heating coil is connected to the connection point E. The inner end of the other heating coil is connected to the resonance capacitor 32.
　加熱コイル４０を構成する二つの加熱コイルは、一方の加熱コイルの内側端が他方の加熱コイルの外側端に接続されて直列に接続される。一方の加熱コイルの外側端は共振コンデンサ３９に接続される。他方の加熱コイルの内側端は接続点Ｇに接続される。 The two heating coils constituting the heating coil 40 are connected in series with the inner end of one heating coil connected to the outer end of the other heating coil. The outer end of one heating coil is connected to the resonance capacitor 39. The inner end of the other heating coil is connected to the connection point G.
　加熱コイル３４を構成する直列に接続された二つの加熱コイルが、加熱コイル４０を構成する直列に接続された二つの加熱コイルとＸ字状に交差するように、これら四つの加熱コイルが配置される。 These four heating coils are arranged so that the two heating coils connected in series constituting the heating coil 34 intersect the two heating coils connected in series constituting the heating coil 40 in an X-shape. The
　図１２Ａは、スイッチング素子３５、３６、４１、４２に供給される駆動信号と、加熱コイル３４、４０に流れる電流とを示す波形図である。図１２Ａは、図１１Ａに示すように加熱コイル３４、４０を配置し、図１０Ａ、図１０Ｂに示すように非磁性材質の鍋を加熱する場合における波形図である。図１２Ｂは、図１２Ａに示す期間ｔ１における、加熱コイル３４、４０に流れる電流の向きを示す。 FIG. 12A is a waveform diagram showing drive signals supplied to the switching elements 35, 36, 41, and 42 and currents flowing through the heating coils 34 and 40. 12A is a waveform diagram in the case where heating coils 34 and 40 are arranged as shown in FIG. 11A and a nonmagnetic material pan is heated as shown in FIGS. 10A and 10B. FIG. 12B shows the direction of the current flowing through the heating coils 34 and 40 in the period t1 shown in FIG. 12A.
　図１３Ａは、スイッチング素子３５、３６、４１、４２に供給される駆動信号と、加熱コイル３４、４０に流れる電流とを示す波形図である。図１３Ａは、図１１Ａに示すように加熱コイル３４、４０を配置し、図１０Ｃ、図１０Ｄに示すように磁性材質の鍋を加熱する場合における波形図である。図１３Ｂは、図１３Ａに示す期間ｔ１における、加熱コイル３４、４０に流れる電流の向きを示す。 FIG. 13A is a waveform diagram showing drive signals supplied to the switching elements 35, 36, 41, 42 and currents flowing through the heating coils 34, 40. FIG. 13A is a waveform diagram in the case where the heating coils 34 and 40 are arranged as shown in FIG. 11A and a magnetic pot is heated as shown in FIGS. 10C and 10D. FIG. 13B shows the direction of the current flowing through the heating coils 34 and 40 in the period t1 shown in FIG. 13A.
　図１２Ａ、図１２Ｂ、図１３Ａ、図１３Ｂを用いて、誘導加熱装置２０Ｃの動作を説明する。まず鍋が加熱コイル３４、４０の上方のトッププレートに載置される。制御部３７は、各スイッチング素子に駆動信号を所定時間供給し、その間に電流検知部４３および電圧検知部４４により検出される値を受信する。 The operation of the induction heating device 20C will be described with reference to FIGS. 12A, 12B, 13A, and 13B. First, the pan is placed on the top plate above the heating coils 34 and 40. The control unit 37 supplies a drive signal to each switching element for a predetermined time, and receives values detected by the current detection unit 43 and the voltage detection unit 44 during that time.
　判定部３７ａは、それらの値をもとに、鍋が非磁性材質であるか、磁性材質であるかを判定する。非磁性材質の鍋には、アルミ製の鍋、銅製の鍋、アルミの割合が多い多層構造の鍋が含まれる。磁性材質の鍋には、ホーロー製の鍋、磁性ステンレス製の鍋が含まれる。 The determination unit 37a determines whether the pan is a non-magnetic material or a magnetic material based on these values. Nonmagnetic material pans include aluminum pans, copper pans, and multi-layer pans with a high percentage of aluminum. Magnetic pots include enamel pots and magnetic stainless steel pots.
　判定部３７ａが、鍋は非磁性材質であると判定した場合、図１２Ａに示すように、制御部３７は、スイッチング素子３５、４１に対して同一の駆動信号を供給し、スイッチング素子３６、４２に対して同一の駆動信号を供給する。スイッチング素子３５、４１に対する駆動信号は、スイッチング素子３６、４２に対する駆動信号とは異なる。 When the determination unit 37a determines that the pan is a non-magnetic material, the control unit 37 supplies the same drive signal to the switching elements 35 and 41 as shown in FIG. Are supplied with the same drive signal. The drive signals for the switching elements 35 and 41 are different from the drive signals for the switching elements 36 and 42.
　これにより、図１０Ａ、図１０Ｂに示すように電流が流れる。このとき、図１２Ａに示すように、加熱コイル３４に流れる電流は、加熱コイル４０に流れる電流と同じ位相を有する。 Thereby, current flows as shown in FIGS. 10A and 10B. At this time, as shown in FIG. 12A, the current flowing through the heating coil 34 has the same phase as the current flowing through the heating coil 40.
　その結果、接続点Ｅから共振コンデンサ３２に向って電流が流れる場合、接続点Ｇから共振コンデンサ３９に向って電流が流れる（図１１Ａ参照）。すなわち、図１２Ｂに示すように、加熱コイル３４には矢印Ｘの方向に電流が流れ、加熱コイル４０には矢印Ｙの方向に電流が流れる。この場合、加熱コイル３４、４０の対向する部分では、同一方向に電流が流れる。 As a result, when a current flows from the connection point E toward the resonance capacitor 32, a current flows from the connection point G toward the resonance capacitor 39 (see FIG. 11A). That is, as shown in FIG. 12B, a current flows through the heating coil 34 in the direction of arrow X, and a current flows through the heating coil 40 in the direction of arrow Y. In this case, current flows in the same direction in the facing portions of the heating coils 34 and 40.
　これにより、隣接する二つの加熱コイルの間で磁界が互いに強め合い、加熱コイルと鍋との磁気結合が向上する。加熱コイルから見た鍋を含む抵抗が増大し、比較的小さい電流で鍋を加熱することができる。そのため、固有抵抗値が比較的低い非磁性材質の鍋を効率良く加熱することができる。 This will strengthen the magnetic field between the two adjacent heating coils and improve the magnetic coupling between the heating coil and the pan. The resistance including the pan seen from the heating coil increases, and the pan can be heated with a relatively small current. Therefore, a nonmagnetic material pan having a relatively low specific resistance can be efficiently heated.
　二つの加熱コイルの間で強い磁界が発生するため、鍋が局所的に加熱される。しかし、非磁性材質の鍋は、磁性材質の鍋より高い熱伝導率を有するため、加熱分布にはあまり影響しない。 】 Since the strong magnetic field is generated between the two heating coils, the pan is locally heated. However, non-magnetic pots have a higher thermal conductivity than magnetic pots and therefore do not significantly affect the heating distribution.
　判定部３７ａが、鍋は磁性材質であると判定した場合、図１３Ａに示すように、制御部３７は、スイッチング素子３５、４２に対して同一の駆動信号を供給し、スイッチング素子３６、４１に対して同一の駆動信号を供給する。スイッチング素子３５、４２に対する駆動信号は、スイッチング素子３６、４１に対する駆動信号とは異なる。 When the determination unit 37a determines that the pan is a magnetic material, the control unit 37 supplies the same drive signal to the switching elements 35 and 42 as shown in FIG. The same drive signal is supplied. The drive signals for the switching elements 35 and 42 are different from the drive signals for the switching elements 36 and 41.
　これにより、図１０Ｃ、図１０Ｄに示すように電流が流れる。このとき、図１３Ａに示すように、加熱コイル３４に流れる電流は、加熱コイル４０に流れる電流とは逆位相を有する。 Thereby, a current flows as shown in FIGS. 10C and 10D. At this time, as shown in FIG. 13A, the current flowing through the heating coil 34 has an opposite phase to the current flowing through the heating coil 40.
　その結果、接続点Ｅから共振コンデンサ３２に向って電流が流れる場合、共振コンデンサ３９から接続点Ｇに向って電流が流れる（図１１Ａ参照）。すなわち、図１３Ｂに示すように、加熱コイル３４には矢印Ｘの方法に電流が流れ、加熱コイル４０には矢印Ｚの方向に電流が流れる。この場合、加熱コイル３４、４０の対向する部分では、逆方向に電流が流れる。 As a result, when a current flows from the connection point E toward the resonance capacitor 32, a current flows from the resonance capacitor 39 toward the connection point G (see FIG. 11A). That is, as shown in FIG. 13B, a current flows through the heating coil 34 in the direction of arrow X, and a current flows through the heating coil 40 in the direction of arrow Z. In this case, a current flows in the opposite direction in the portion where the heating coils 34 and 40 face each other.
　これにより、隣接する二つの加熱コイルの間で磁界が互いに打ち消し合い、強い磁界の発生が抑制される。そのため、局所的な加熱を抑制して、鍋を均一に加熱することができる。 This causes the magnetic fields to cancel each other between two adjacent heating coils, thereby suppressing the generation of a strong magnetic field. Therefore, local heating can be suppressed and the pan can be heated uniformly.
　以上のように、本実施の形態では、制御部３７は、スイッチング素子３５、３６、４１、４２の導通パターンを鍋の材質に応じて変更することで、リレーを使用せずに共振コンデンサの合成容量を変更することができる。 As described above, in the present embodiment, the control unit 37 changes the conduction pattern of the switching elements 35, 36, 41, and 42 according to the material of the pan, thereby synthesizing the resonant capacitor without using a relay. The capacity can be changed.
　本開示は、鉄系の鍋、アルミ系の鍋のいずれをも加熱可能な誘導加熱調理器に適用可能である。 This disclosure can be applied to an induction heating cooker that can heat both iron-based pans and aluminum-based pans.
　１、１０１　商用電源
　２　整流回路
　３、１０２　チョークコイル
　４　コンデンサ
　５、６、９、１０、３５、３６、４１、４２、１０６、１０７　スイッチング素子
　７ａ、７ｂ、１１ａ、１１ｂ、３４、４０、１０５　加熱コイル
　８　共振コンデンサ
　１２、３２、３３、３８、３９、１０４　共振コンデンサ
　１３、１０８　鍋
　１４、３７、１１０　制御部
　１４ａ、３７ａ　判定部
　１５、４３、１０９　電流検知部
　１６、１７、４４　電圧検知部
　１８、１９、４５、４６　インバータ
　２０Ａ、２０Ｂ、２０Ｃ　誘導加熱装置
　３１　直流電源
　１０３　平滑コンデンサ DESCRIPTION OF SYMBOLS 1,101 Commercial power supply 2 Rectifier circuit 3,102 Choke coil 4 Capacitor 5, 6, 9, 10, 35, 36, 41, 42, 106, 107 Switching element 7a, 7b, 11a, 11b, 34, 40, 105 Heating Coil 8 Resonance capacitor 12, 32, 33, 38, 39, 104 Resonance capacitor 13, 108 Pan 14, 37, 110 Control unit 14a, 37a Determination unit 15, 43, 109 Current detection unit 16, 17, 44 Voltage detection unit 18 19, 45, 46 Inverter 20A, 20B, 20C Induction heating device 31 DC power supply 103 Smoothing capacitor

Claims (6)

  1. 　被加熱物を載置するように構成されたトッププレートと、
    　前記トッププレートの下方に配置された複数の加熱コイルと、
    　前記複数の加熱コイルに電力を供給するように構成されたインバータと、
    　前記インバータを制御するように構成された制御部と、
    　被加熱物が鉄系の負荷であるか、アルミ系の負荷であるかを判定するように構成された判定部と、を有し、
    　前記制御部は、前記判定部による判定結果に応じて、前記複数の加熱コイルに流れる電流の向きを制御するように構成された誘導加熱装置。     A top plate configured to place an object to be heated;
    A plurality of heating coils disposed below the top plate;
    An inverter configured to supply power to the plurality of heating coils;
    A controller configured to control the inverter;
    A determination unit configured to determine whether the object to be heated is an iron-based load or an aluminum-based load; and
    The said control part is an induction heating apparatus comprised so that the direction of the electric current which flows into the said several heating coil might be controlled according to the determination result by the said determination part.
  2. 　前記被加熱物が鉄系の負荷であると前記判定部が判定した場合、前記制御部が、前記複数の加熱コイルのうちの隣接する二つの加熱コイルに逆方向に電流を流すように構成された、請求項１記載の誘導加熱装置。 When the determination unit determines that the object to be heated is an iron-based load, the control unit is configured to flow a current in the opposite direction to two adjacent heating coils of the plurality of heating coils. The induction heating apparatus according to claim 1.
  3. 　前記被加熱物がアルミ系の負荷であると前記判定部が判定した場合、前記制御部が、前記複数の加熱コイルのうちの隣接する二つの加熱コイルに同一方向に電流を流すように構成された、請求項１記載の誘導加熱装置。 When the determination unit determines that the object to be heated is an aluminum load, the control unit is configured to flow current in the same direction to two adjacent heating coils of the plurality of heating coils. The induction heating apparatus according to claim 1.
  4. 　前記隣接する二つの加熱コイル間の距離が４０ｍｍ以下に設定された、請求項１に記載の誘導加熱装置。 The induction heating apparatus according to claim 1, wherein a distance between the two adjacent heating coils is set to 40 mm or less.
  5. 　前記複数の加熱コイルが四つの加熱コイルを含み、直列または並列に接続された二つの加熱コイルをそれぞれ含む二つの組がＸ字状に交差するように、前記四つの加熱コイルが配置された、請求項１に記載の誘導加熱装置。 The four heating coils are arranged such that the plurality of heating coils include four heating coils, and two sets each including two heating coils connected in series or in parallel intersect in an X shape. The induction heating apparatus according to claim 1.
  6. 　直流電源と、
    　互いに直列に接続されるとともに、前記直流電源に並列に接続された第１のスイッチング素子および第２のスイッチング素子と、
    　互いに直列に接続されるとともに、前記直流電源に並列に接続された第３のスイッチング素子および第４のスイッチング素子と、
    　一端が、前記第１のスイッチング素子と前記第２のスイッチング素子との接続点に接続された第１の加熱コイルと、
    　一端が、前記第１の加熱コイルの他端に接続された第１の共振コンデンサと、
    　一端が、前記第３のスイッチング素子と前記第４のスイッチング素子との接続点に接続された第２の加熱コイルと、
    　一端が前記第２の加熱コイルの他端に接続され、他端が前記第１の共振コンデンサの他端に接続された第４の共振コンデンサと、
    　一端が前記第１の共振コンデンサと前記第４の共振コンデンサとの接続点に接続され、他端が前記直流電源の正極に接続された第３の共振コンデンサと、
    　一端が前記第１の共振コンデンサと前記第４の共振コンデンサとの接続点に接続され、他端が前記直流電源の負極に接続された第２の共振コンデンサと、を備え、
    　前記制御部は、前記第１のスイッチング素子と前記第２のスイッチング素子とを交互にオンし、前記第３のスイッチング素子と前記第４のスイッチング素子とを交互にオンするように構成され、
    　前記制御部は、被加熱物が非磁性材質である場合、前記第１のスイッチング素子と前記第３のスイッチング素子とを同時にオンし、第２のスイッチング素子と前記第４のスイッチング素子とを同時にオンするように構成され、
    　前記制御部は、被加熱物が磁性材質である場合、前記第１のスイッチング素子と前記第４のスイッチング素子とを同時にオンし、第２のスイッチング素子と前記第３のスイッチング素子とを同時にオンするように構成された、請求項１に記載の誘導加熱装置。     DC power supply,
    A first switching element and a second switching element connected in series to each other and connected in parallel to the DC power supply;
    A third switching element and a fourth switching element connected in series to each other and connected in parallel to the DC power supply;
    A first heating coil having one end connected to a connection point between the first switching element and the second switching element;
    A first resonant capacitor having one end connected to the other end of the first heating coil;
    A second heating coil having one end connected to a connection point between the third switching element and the fourth switching element;
    A fourth resonant capacitor having one end connected to the other end of the second heating coil and the other end connected to the other end of the first resonant capacitor;
    A third resonance capacitor having one end connected to a connection point between the first resonance capacitor and the fourth resonance capacitor and the other end connected to a positive electrode of the DC power source;
    A second resonance capacitor having one end connected to a connection point between the first resonance capacitor and the fourth resonance capacitor, and the other end connected to a negative electrode of the DC power source;
    The controller is configured to alternately turn on the first switching element and the second switching element, and alternately turn on the third switching element and the fourth switching element,
    When the object to be heated is made of a non-magnetic material, the control unit turns on the first switching element and the third switching element at the same time, and turns on the second switching element and the fourth switching element at the same time. Configured to turn on,
    When the object to be heated is a magnetic material, the control unit turns on the first switching element and the fourth switching element at the same time, and turns on the second switching element and the third switching element at the same time. The induction heating apparatus according to claim 1, wherein the induction heating apparatus is configured to.
PCT/JP2018/021632 2017-06-09 2018-06-06 Induction heating device WO2018225755A1 (en)

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WO2020133101A1 (en) * 2018-12-27 2020-07-02 英都斯特(无锡)感应科技有限公司 Star-star type three-phase induction thermal reactor
WO2020133100A1 (en) * 2018-12-27 2020-07-02 江南大学 Intermittent inductive thermal reactor
CN112394244A (en) * 2019-08-19 2021-02-23 广东美的白色家电技术创新中心有限公司 Detection circuit, electric appliance and control method
WO2022231131A1 (en) * 2021-04-30 2022-11-03 엘지전자 주식회사 Induction heating type cooktop
WO2022231065A1 (en) * 2021-04-30 2022-11-03 엘지전자 주식회사 Induction heating type cooktop

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Publication number Priority date Publication date Assignee Title
WO2020133101A1 (en) * 2018-12-27 2020-07-02 英都斯特(无锡)感应科技有限公司 Star-star type three-phase induction thermal reactor
WO2020133100A1 (en) * 2018-12-27 2020-07-02 江南大学 Intermittent inductive thermal reactor
CN112394244A (en) * 2019-08-19 2021-02-23 广东美的白色家电技术创新中心有限公司 Detection circuit, electric appliance and control method
CN112394244B (en) * 2019-08-19 2021-09-14 广东美的白色家电技术创新中心有限公司 Detection circuit, electric appliance and control method
WO2022231131A1 (en) * 2021-04-30 2022-11-03 엘지전자 주식회사 Induction heating type cooktop
WO2022231065A1 (en) * 2021-04-30 2022-11-03 엘지전자 주식회사 Induction heating type cooktop

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