JP2018125312A - Induction heating cooker and non-contact power supply system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve an induction heating cooker capable of preventing interference to a radio signal caused by leakage magnetic flux occurring at a coil when the induction heating cooker performs radio communication with a receiving device in the case where the coil of the induction heating cooker is used as a non-contact power feed coil.SOLUTION: An induction heating cooker comprises: a top plate where a receiving device or a heated object is placed; a first heating part 11 which is arranged under the top plate and performs non-contact power feeding to the receiving device and inductively heating the heated object; a drive circuit 51 for outputting current to the first heating part 11; and a control part 45 which performs control to set a value of current output from the drive circuit during a first time period at a smaller value than that during a second time period, and determines a cycle of radio communication with the receiving device, and changes in the case where the radio communication with the receiving device is cyclic, the first time period and the second time period based on the cycle, in which the first time period is a time period to perform radio communication with the receiving device and the second time period is a time period not to perform radio communication with the receiving device.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an induction heating cooker that heats an object to be heated by electromagnetic induction, and a non-contact power feeding system that performs non-contact power feeding by electromagnetic induction.

  Conventionally, the output of the induction heating cooker is the operation unit installed in the induction heating cooker body, accepting selection of input heating power, that is, input power, or selection of cooking menu such as a kettle mode, fried food mode, etc. It is controlled according to. On the other hand, in order to improve convenience, a technology has been developed that uses a coil, which is a heating means of an induction heating cooker, for non-contact power feeding.

  In an induction heating cooker that performs non-contact power feeding, if the load placed on the top plate is a heated object such as a pan, power control for heating the heated object is performed according to the received selection result. On the other hand, when the load placed on the top plate is a power receiving device such as a coffee mill or a jarpot, the required power and the range of power that can be input differ depending on the power receiving device. It is necessary to perform different power control depending on the situation. For this reason, the induction heating cooker needs to detect whether the load is an object to be heated or a power receiving device, and when the load is a power receiving device, the electric power required for the power receiving device is It needs to be detected.

  Patent Document 1 discloses a technique in which, in an induction heating cooker that performs non-contact power feeding, the induction heating cooker performs wireless communication at the start of operation in order to determine whether the load is an object to be heated or a power receiving device. Is disclosed. The induction heating cooker described in Patent Document 1 determines whether a load is a heated object or a power receiving device by performing wireless communication when the induction heating cooker starts operation, and the load receives power. In the case of a device, information about the power required by the power receiving device is acquired from the power receiving device by wireless communication.

International Publication No. 2013/094174

  An induction heating cooker generates high-frequency magnetic flux with a heating coil disposed below the top plate and performs heating. At this time, a leakage magnetic flux is generated from the heating coil. For this reason, when using wireless communication to determine whether the load is an object to be heated or a power receiving device and to acquire information about the power required by the power receiving device, the leakage magnetic flux is wireless. There is a problem that it may interfere with a signal and prevent transmission of information.

  This invention is made in view of the above, Comprising: When using the coil of an induction heating cooking appliance as a non-contact electric power feeding coil, when an induction heating cooking appliance performs radio | wireless communication with a receiving device, it generate | occur | produces with a coil It aims at obtaining the induction heating cooking appliance which can suppress the interference to the radio signal by the leaked magnetic flux.

In order to solve the above-described problems and achieve the object, an induction heating cooker according to the present invention is an induction heating cooker capable of performing wireless communication with a power receiving device, and the induction heating cooker is connected to a power receiving device. Used for non-contact power supply and heating of the object to be heated. The power receiving device or the top plate on which the object to be heated is placed, and the power receiving device arranged in the lower part of the top plate for non-contact power supply to induce the object to be heated. A heating unit that heats, a drive circuit that outputs a current to the heating unit, and a control that sets a current output from the drive circuit to a value smaller than a current in the second period in the first period, A control unit that determines a period of wireless communication between the first and second periods when the wireless communication with the power receiving device has periodicity, and changes the first period and the second period based on the period. Is a period for performing wireless communication with the power receiving device, and the second Period is a period that does not perform the power receiving apparatus and wireless communication.

  According to the present invention, when an induction heating cooker coil is used as a non-contact power supply coil, when the induction heating cooker performs wireless communication with a power receiving device, interference with a radio signal due to leakage magnetic flux generated in the coil. There is an effect that can be suppressed.

The exploded perspective view of the induction heating cooking appliance concerning Embodiment 1 The figure which shows the structural example of the drive circuit of the induction heating cooking appliance concerning Embodiment 1. FIG. The figure which shows an example of the control signal input from IGBT to the IGBT of the first embodiment The figure which shows another example of the control signal input into IGBT of Embodiment 1 from a control part. The figure which shows the example of another drive circuit of the induction heating cooking appliance concerning Embodiment 1. FIG. FIG. 5 is a diagram illustrating an example of a control signal for controlling on / off of the IGBT illustrated in FIG. 5 according to the first embodiment. FIG. 3 is a diagram illustrating a configuration example of a control circuit according to the first embodiment. The figure which shows the structural example of the power receiving apparatus of Embodiment 1, and the structural example of the control part of an induction heating cooking appliance. A flowchart showing an example of a load determination processing procedure according to the first embodiment. The figure which shows an example of the relationship between the high frequency electric power which the drive circuit of Embodiment 1 supplies to a 1st heating part, and the period when a communication part performs radio | wireless communication. The figure which shows another example of the relationship between the high frequency electric power which the drive circuit of Embodiment 1 supplies to a 1st heating part, and the period when a communication part performs radio | wireless communication. Flowchart showing an example of the power change control procedure of the first embodiment The flowchart which shows another example of the load determination processing procedure of Embodiment 1. The flowchart which shows an example of the non-contact electric power feeding operation | movement procedure including the determination using the communication limit period of Embodiment 1. The figure which shows the structural example of the control part of the induction heating cooking appliance concerning Embodiment 2. FIG. FIG. 9 is a diagram illustrating an example of a relationship between high-frequency power supplied by a driving circuit and a period in which a communication unit performs wireless communication in Embodiment 2. Flowchart illustrating an example of a communication control procedure according to the second embodiment

  Below, the induction heating cooking appliance and non-contact electric power feeding system concerning embodiment of this invention are demonstrated in detail based on drawing. Note that the present invention is not limited to the embodiments.

Embodiment 1 FIG.
FIG. 1 is an exploded perspective view of the induction heating cooker according to the first embodiment of the present invention. Induction heating cooker 100 of the present embodiment can communicate with power receiving device 60 by wireless communication. As shown in FIG. 1, the induction heating cooker 100 of the present embodiment includes a first heating unit 11, a second heating unit 12, a third heating unit 13, and a grill unit 14. The first heating unit 11, the second heating unit 12, and the third heating unit 13 are accommodated in the main body housing 7. The induction heating cooker 100 has a top plate 4 on which an object to be heated or a power receiving device 60 can be placed. Hereinafter, the main body casing 7 and each part accommodated in the main body casing 7, that is, the portion excluding the top plate 4 in the induction heating cooker 100 may be referred to as a main body. In the following description, the induction heating cooker 100 will be described as an example of the non-contact power feeding device according to the present invention. Not limited to this, the present invention can be applied to a non-contact power supply apparatus that has a function of communicating with the power receiving device 60 and performs non-contact power supply.

  The top plate 4 includes a first heating port 1, a second heating port 2, and a third heating port 3 as heating ports for inductively heating an object to be heated which is a metal load made of metal. The first heating port 1, the second heating port 2, and the third heating port 3 correspond to the heating ranges of the first heating unit 11, the second heating unit 12, and the third heating unit 13, respectively. Each of which can place an object to be heated. The object to be heated placed on each heating port is induction-heated by a heating unit corresponding to each heating port. Moreover, when the power receiving apparatus 60 provided with a coil is placed on the first heating port 1 of the top plate 4 in the first heating port 1, the second heating port 2, and the third heating port 3, The induction heating cooker 100 performs non-contact power supply to the power receiving device 60. FIG. 1 shows an example in which the object to be heated 5 is placed as the load on the second heating port 2 of the top plate 4 and the power receiving device 60 is placed on the first heating port 1 of the top plate 4. .

  In the example shown in FIG. 1, a first heating unit 11 and a second heating unit 12 are provided side by side on the front side of the main body, and a third heating unit 13 is provided at substantially the center on the back side of the main body. Yes. Note that the near side is the side on which the operator is positioned when the operator uses the induction heating cooker 100, and is the lower left side of the page of FIG. In addition, arrangement | positioning of each heating port is not restricted to this. For example, three heating ports may be arranged side by side in a substantially straight line. Moreover, you may arrange | position so that the position of the depth direction of the center of the 1st heating part 11 and the center of the 2nd heating part 12 may differ. In the first embodiment, three heating units are provided, but the number of heating units is not limited to three, and may be one or two, or four or more. . The top plate 4 is provided with heating ports corresponding to the number of heating units.

  The top plate 4 is entirely made of a material that transmits infrared rays, such as heat-resistant tempered glass, crystallized glass, and the like, and a rubber packing is provided between the outer periphery of the upper surface of the main body housing 7 of the induction heating cooker 100, Alternatively, it is fixed in a watertight state through a sealing material or a combination thereof. The top plate 4 has a rough heating object or a power receiving device in each heating range of the first heating unit 11, the second heating unit 12, and the third heating unit 13, that is, a range indicating each heating port. A circular display indicating a proper placement position, that is, a pan position display is formed by applying paint or printing.

  In order to receive the setting of the input heating power at the time of heating a to-be-heated object in the 1st heating part 11, the 2nd heating part 12, and the 3rd heating part 13, ie, input power, and a cooking menu in the top plate 4 As an input device, that is, a receiving unit, an operating unit 40a, an operating unit 40b, and an operating unit 40c are provided. Examples of the cooking menu include a water heating mode and a fried food mode. Hereinafter, the operation unit 40a, the operation unit 40b, and the operation unit 40c may be collectively referred to as the operation unit 40. The operation unit 40a, the operation unit 40b, and the operation unit 40c are, for example, buttons, levers, and touch panels.

  As a notification means, the top plate 4 has an operating state of the induction heating cooker 100, input information and control contents input from the operation unit 40 and the power receiving device 60, information on the power receiving device 60 during wireless communication, presence / absence of wireless communication Etc., a display unit 41a, a display unit 41b, and a display unit 41c are provided. That is, the display units 41a, 41b, and 41c are information indicating the operation state of the induction heating cooker 100, setting information for the induction heating cooker 100, information based on a control signal received from the power receiving device 60, and the power receiving device 60. At least one of the information indicating the communication state is displayed. The display unit 41a, the display unit 41b, and the display unit 41c are configured by, for example, a liquid crystal monitor and an LED (Light Emitting Diode). Hereinafter, the display unit 41a, the display unit 41b, and the display unit 41c may be collectively referred to as the display unit 41. Note that the notification in the present embodiment may include an operation recognized by the operator by sound as well as display by images and characters.

  In addition, in the example of FIG. 1, although the operation parts 40a-40c are provided for every heating opening, you may provide the operation part which bundled at least 2 or more of heating openings. Similarly, a display unit that collects at least two of the heating ports may be provided. In addition, a display operation unit that serves as both the operation unit 40 and the display unit 41 may be provided, and specific configurations of the operation unit and the display unit are not particularly limited.

  The grill part 14 has a heater as load heating means. Moreover, the grill part 14 may be provided with a coil as a heating means to perform induction heating, similarly to the first heating part 11, the second heating part 12, and the third heating part 13. In this case, the heating means of the grill unit 14 is also provided with a drive circuit as in the first heating unit 11, the second heating unit 12, and the third heating unit 13. Below, the description of operation | movement is abbreviate | omitted in this Embodiment on the assumption that the grill part 14 uses a heater as a load heating means. When the grill unit 14 performs induction heating, the heating unit of the grill unit 14 is similar to the control corresponding to the first heating unit 11, the second heating unit 12, and the third heating unit 13. What is necessary is just to implement control.

  As described above, the first heating unit 11, the second heating unit 12, and the third heating unit 13 are provided below the top plate 4 and inside the main body housing 7. Each heating unit is constituted by a coil, that is, a heating coil.

  Furthermore, inside the main body casing 7 of the induction heating cooker 100, there is a drive unit 50 that supplies power to the heating coils of the first heating unit 11, the second heating unit 12, and the third heating unit 13. A control unit 45 for controlling the entire operation of the induction heating cooker 100 including the drive unit 50 and a communication unit 6 for performing wireless communication with the power receiving device 60 are provided. For example, Wi-Fi (registered trademark), Bluetooth (registered trademark), or infrared communication can be used for wireless communication between the induction heating cooker 100 and the power receiving device 60.

  Each of the heating coils constituting the first heating unit 11, the second heating unit 12, and the third heating unit 13 has a substantially circular planar shape, and has a conductive wire made of any metal with an insulating film. It is configured by winding in the circumferential direction. As the metal constituting the heating coil, for example, copper or aluminum can be used. In the induction heating cooker 100, the induction heating operation is performed by supplying high-frequency power to each heating coil by the driving unit 50.

  The drive unit 50 includes three drive circuits 51 corresponding to the respective heating units. FIG. 2 is a diagram illustrating a configuration example of the drive circuit 51 of the induction heating cooker 100 according to the first embodiment. Although FIG. 2 shows a configuration example of the drive circuit 51 corresponding to the first heating unit 11, the drive circuit corresponding to each heating unit may be the same or different for each heating unit.

  As shown in FIG. 2, the drive circuit 51 includes a DC power supply circuit 22, an inverter circuit 23, a resonance capacitor 24, an input current detection unit 25a, and an output current detection unit 25b.

  The input current detection unit 25a detects a current input from the AC power supply 21 to the DC power supply circuit 22, that is, a current input to the drive circuit 51, and outputs a detected value, that is, a voltage signal indicating the input current value to the control unit 45. Output. The AC power source 21 is, for example, a commercial AC power source.

  The DC power supply circuit 22 includes a diode bridge 22a, a reactor 22b, and a smoothing capacitor 22c, converts an AC voltage input from the AC power supply 21 into a DC voltage, and outputs the DC voltage to the inverter circuit 23.

  The inverter circuit 23 is a so-called half-bridge type inverter in which IGBTs (Insulated Gate Bipolar Transistors) 23 a and 23 b as switching elements are connected in series to the output of the DC power supply circuit 22. In the inverter circuit 23, diodes 23c and 23d as flywheel diodes are connected in parallel with the IGBTs 23a and 23b, respectively. The inverter circuit 23 converts the DC power output from the DC power supply circuit 22 into high-frequency AC power of about 20 kHz to 80 kHz, so-called high-frequency power, and from the first heating unit 11 that is a heating coil and the resonance capacitor 24. To the resonant circuit.

  The resonance capacitor 24 is connected in series to the first heating unit 11, and this resonance circuit has a resonance frequency according to the inductance of the first heating unit 11, the capacity of the resonance capacitor 24, and the like. Note that the inductance of the first heating unit 11 changes according to the characteristics of the coil of the power receiving device 60 or the object to be heated 5 when the coil of the power receiving device 60 or the object to be heated 5 is magnetically coupled. Accordingly, the resonance frequency of the resonance circuit changes.

  With this configuration, a high frequency current of about several tens of A flows through the first heating unit 11, and the high frequency magnetic flux generated by the flowing high frequency current causes the first heating unit 11 to be covered on the top plate 4 immediately above the first heating unit 11. When the heated object 5 is placed, the object to be heated 5 is induction-heated. On the other hand, when the power receiving device 60 is placed on the top plate 4 directly above the first heating unit 11, the current flows to the power receiving device 60 by electromagnetic induction due to the above-described high-frequency magnetic flux, whereby the power receiving device 60 is connected to the power receiving device 60. Power is supplied. That is, when the power receiving device 60 is placed on the top plate 4 directly above the first heating unit 11, the coil serving as the first heating unit 11 functions as a power transmission side coil, and the coil of the power receiving device 60 receives power. Functions as a side coil.

  The IGBTs 23a and 23b, which are switching elements, are composed of, for example, a silicon-based semiconductor, but may be configured using a wide band gap semiconductor such as silicon carbide or a gallium nitride-based material.

  By using a wide band gap semiconductor for the switching element, the conduction loss of the switching element can be reduced, and the heat radiation of the driving unit 50 is good even when the switching frequency, that is, the driving frequency is set to a high frequency, that is, the switching is performed at high speed. Become. For this reason, the heat dissipation fin of the drive unit 50 can be reduced in size, and the drive unit 50 can be reduced in size and cost.

  The output current detection unit 25 b is connected to a resonance circuit composed of the first heating unit 11 and the resonance capacitor 24. The output current detection unit 25b detects, for example, a current flowing through the first heating unit 11, that is, a current output from the drive circuit 51, and outputs a voltage signal corresponding to the detected value to the control unit 45.

  FIG. 3 is a diagram illustrating an example of a control signal input from the control unit 45 to the IGBTs 23a and 23b. This control signal is, for example, a signal indicating one of a value indicating that the IGBTs 23a and 23b are turned on and a value indicating that the IGBTs 23a and 23b are turned off. In the example of FIG. 3, an example is shown in which ON is indicated when the signal value of the control signal is High, and OFF is indicated when the signal value of the control signal is Low, but the values of the control signal and the IGBTs 23 a and 23 b are illustrated. The relationship between the on / off state is not limited to this example. The IGBTs 23a and 23b are turned on / off in a repetition cycle called a switching cycle. The on-time and off-time are each half the switching period. As shown in FIG. 3, the IGBT 23a and the IGBT 23b provide a 180 ° phase difference at the turn-on timing. Thereby, IGBT23a and IGBT23b do not turn ON simultaneously.

  When the switching cycle is shortened, the switching frequency that is the reciprocal of the switching cycle is increased, and the impedance of the first heating unit 11 is increased. Therefore, the high-frequency current supplied by the drive circuit 51 is decreased, and the output power is suppressed. On the other hand, if the switching cycle is lengthened, the switching frequency is lowered and the impedance of the first heating unit 11 is reduced, so that the high-frequency current supplied by the drive circuit 51 is increased and the output power is increased. The above control method is called switching frequency control or pulse frequency control because the output power is controlled by the height of the switching frequency. Note that when the IGBT 23a and the IGBT 23b are simultaneously turned on, the inverter circuit 23 is short-circuited. Therefore, in an actual circuit, a period called a dead time in which both the IGBTs 23a and 23b are turned off is provided. For this reason, the on-time is shorter than half the switching period, and the off-time is longer than half the switching period.

  FIG. 4 is a diagram showing another example of control signals for controlling on / off of the IGBTs 23a and 23b. Similar to the example of FIG. 3, the control signal is a signal indicating one of a value indicating that the IGBTs 23 a and 23 b are turned on and a value indicating that the IGBTs 23 a and 23 b are turned off. The IGBTs 23a and 23b are turned on / off at a repetition cycle called a switching cycle, as in the example of FIG. Similarly to the example of FIG. 3, the IGBT 23a and the IGBT 23b provide a 180 ° phase difference at the turn-on timing. For this reason, the IGBT 23a and the IGBT 23b are not turned on at the same time.

  In the example of FIG. 4, unlike the example of FIG. 3, the on-time is a time shorter than half of the switching period. When both the IGBTs 23a and 23b are off, the inverter circuit 23 does not output power. For this reason, if ON time is shortened, the high frequency current which the drive circuit 51 supplies to the 1st heating part 11 will become small, and output electric power will be suppressed. The ratio of the on-time to the switching period is called a duty ratio, and the above control method is called duty ratio control because the output power is controlled by the duty ratio. In the example of FIG. 4, since the duty ratio is smaller than that of the example of FIG. 3, the output power from the drive circuit 51 is smaller than that of the example of FIG.

  FIG. 5 is a diagram illustrating an example of another drive circuit 51 of the induction heating cooker 100 according to the first embodiment. In FIG. 5, the same components as those in FIG. 2 are denoted by the same reference numerals as those in FIG. In the configuration example shown in FIG. 5, IGBTs 23e and 23f as switching elements and diodes 23g and 23h as flywheel diodes are added to the drive circuit 51 shown in FIG. The inverter circuit 23 shown in FIG. 5 has a configuration in which IGBTs 23e and 23f and diodes 23g and 23h are added to the inverter circuit 23 shown in FIG. 2, and is a so-called full bridge type inverter. As in the inverter circuit 23 shown in FIG. 2, the inverter circuit 23 shown in FIG. 5 converts the DC power output from the DC power supply circuit 22 into high-frequency AC power of about 20 kHz to 80 kHz, and the first heating is performed. This is supplied to a resonance circuit comprising the unit 11 and the resonance capacitor 24.

  FIG. 6 is a diagram illustrating an example of a control signal for controlling on / off of the IGBTs 23a, 23b, 23e, and 23f illustrated in FIG. The IGBTs 23a, 23b, 23e, and 23f are turned on / off at a repetition cycle called a switching cycle. The on-time and off-time are each half the switching period. The IGBT 23a and the IGBT 23b provide a 180 ° phase difference at the turn-on timing. Thereby, IGBT23a and IGBT23b do not turn ON simultaneously. The IGBT 23e and the IGBT 23f provide a 180 ° phase difference at the turn-on timing. Thereby, IGBT23e and IGBT23f are not turned ON simultaneously.

  Inverter circuit 23 supplies power in a period in which both IGBT 23a and IGBT 23f, or IGBT 23b and IGBT 23e are on. By providing a phase difference between the timing at which the IGBT 23a is turned on and the timing at which the IGBT 23e is turned on, a period during which both the IGBT 23a and the IGBT 23f or the IGBT 23b and the IGBT 23e are turned on is provided, and the power supplied by the inverter circuit 23 is controlled. The above control method is called phase control because the output power is controlled by the phase difference. When IGBT 23a and IGBT 23b, or IGBT 23e and IGBT 23f are simultaneously turned on, inverter circuit 23 is short-circuited. For this reason, in an actual circuit, a period in which both IGBT 23a and IGBT 23b are turned off and a period in which both IGBT 23e and IGBT 23f are turned off are provided. For this reason, the on-time is shorter than half the switching period, and the off-time is longer than half the switching period.

  In addition, the structure of the drive circuit 51 of the induction heating cooking appliance 100 which concerns on Embodiment 1 is not restricted to the example shown in FIG. 2, FIG. 5, For example, you may comprise by circuit systems, such as a one-stone voltage resonance circuit. it can. Similar to the inverter circuit 23 of FIG. 2, the monolithic voltage resonance circuit converts the DC power output from the DC power supply circuit 22 into a high-frequency AC power of about 20 kHz to 80 kHz, and the first heating unit 11 and the resonance capacitor 24. To a resonant circuit consisting of

  The control unit 45 is configured so that the drive unit 50 has the first heating unit 11 and the second heating unit 12 in accordance with signals given from the input current detection unit 25a, the output current detection unit 25b, the operation unit 40a, and the communication unit 6. The control signal for controlling the high frequency electric power supplied to the 3rd heating part 13 is transmitted.

  In addition, the control unit 45 transmits a control signal for notifying the operation state of the induction heating cooker 100, the control unit 40, the control contents of the power receiving device 60, and the like to the communication unit 6.

  The communication unit 6 is a wireless communication unit for performing wireless communication with the power receiving device 60 and can transmit and receive wireless signals. Specifically, the control signal received from the control unit 45 can be subjected to transmission processing according to the communication method with the power receiving device 60 and transmitted to the power receiving device 60 as a radio signal. Alternatively, information transmitted as a radio signal from the power receiving device 60 can be received, information can be extracted from the radio signal, and transmitted to the control unit 45. Alternatively, both the above-described wireless signal transmission operation and wireless signal reception operation can be performed.

  The communication unit 6 is connected to the control unit 45 by wiring. However, the longer the wiring, the more susceptible to noise, so the communication unit 6 and the control unit 45 are arranged close to each other, and the communication unit 6 and the control unit 45 are connected. It is desirable to shorten the wiring to be connected.

  The communication unit 6 includes an antenna unit that transmits, receives, or transmits / receives a radio signal therein, and the antenna unit of the communication unit 6 is directly below the top plate 4 in order to facilitate transmission / reception of the radio signal. It is desirable to arrange in.

  Note that the control unit 45 is realized by a processing circuit. Even if the processing circuit is dedicated hardware, the CPU (Central Processing Unit, a central processing unit, a CPU that executes a program stored in the memory and the memory, A control circuit including a processing device, an arithmetic device, a microprocessor, a microcomputer, a processor, and a DSP (Digital Signal Processor) may be used. Here, the memory is, for example, RAM (Random Access Memory), ROM (Read Only Memory), flash memory, EPROM (Erasable Programmable Read Only Memory, etc.) Non-volatile or volatile semiconductor memory, magnetic disk, flexible disk, optical disk, compact disk, mini disk, DVD (Digital Versatile Disk), and the like are applicable.

  When the control unit 45 is realized by dedicated hardware, the processing circuit can be, for example, a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC (Application Specific Integrated Circuit), or an FPGA (Field). Programmable Gate Array) or a combination thereof.

  When the control unit 45 is realized by a control circuit including a CPU, the control circuit is, for example, a control circuit 400 having a configuration shown in FIG. As shown in FIG. 7, the control circuit 400 includes a processor 401 that is a CPU and a memory 402. When the control unit 45 is realized by the control circuit 400, it is realized by the processor 401 reading and executing a program stored in the memory 402 and corresponding to the process of the control unit 45. The memory 402 is also used as a temporary memory in each process executed by the processor 401.

  FIG. 8 is a diagram illustrating a configuration example of the power receiving device 60 and a configuration example of the control unit 45 of the induction heating cooker 100. In addition, in FIG. 8, the example provided with the display operation part 43 which served as the operation part 40 and the display part 41 is shown. As shown in FIG. 8, the power receiving device 60 converts the received power into a coil 61 used for power reception and a desired voltage and current, and the operation of the power receiving device 60 via the communication unit 64. Therefore, it includes a conversion circuit 62 that transmits information such as power, current, and voltage necessary for the outside, a load 63 that operates by the converted power, and a communication unit 64 that performs wireless communication with the induction heating cooker 100. When power is supplied to the power receiving device 60, the conversion circuit 62 of the power receiving device 60 communicates information such as power, current, and voltage necessary for the operation of the power receiving device 60 together with information indicating that the power receiving device 60 is in communication. It transmits via the part 64. Hereinafter, information such as power, current, and voltage necessary for the operation of the power receiving device 60 will be referred to as information regarding necessary power. The power receiving device 60 is, for example, a coffee mill, a blender, or a jar pot. When the power receiving device 60 is a coffee mill or a blender, the load 63 is a motor, and when the power receiving device 60 is a jar pot or the like, the load 63 is a heater realized by a heating wire.

  As shown in FIG. 8, the control unit 45 includes a calculation unit 451, a communication cycle detection unit 452, and a drive control unit 453. In FIG. 8, the component concerning control of the 1st heating part 11 and the 1st heating part 11 among the induction heating cooking appliances 100 is illustrated, the 2nd heating part 12 and the 3rd heating part 13, and these The components related to the control are omitted from illustration.

  Next, operation | movement of the induction heating cooking appliance 100 concerning Embodiment 1 is demonstrated. Hereinafter, the first heating unit 11, the second heating unit 12, and the third heating unit 13 are also referred to as a heating unit 11, a heating unit 12, and a heating unit 13, respectively.

  The calculating part 451 performs the process which determines whether the load mounted in the heating port corresponding to each of the heating parts 11-13 is the to-be-heated material 5 or the receiving device 60, ie, a load determination process. . When the loads placed on the heating units 11 to 13 are the object to be heated 5, the calculation unit 451 calculates target power for each of the heating units 11 to 13 based on input information input from the operation unit 40. Then, the target power is instructed to the drive control unit 453. The target power is a command value calculated according to the cooking menu or the input heating power input from the operation unit 40. The drive control unit 453 turns on each switching element of the inverter circuit 23 of the drive circuit 51 based on the target power, the detected current value by the input current detecting unit 25a, and the detected current value by the output current detecting unit 25b. A control signal for controlling / off is generated and input to the inverter circuit 23.

  When the input heating power is not instructed by electric power, for example, instructed by strong, medium, weak, etc., the calculation unit 451 converts the input information into electric power and sets the value obtained by the conversion to the target electric power. Set. Moreover, when instruct | indicated by the cooking menu, the calculating part 451 calculates the target electric power for every heating parts 11-13 according to the operation information of the input electric power for every predetermined cooking menu. The operation information of the input power is, for example, a first heating port 1, a temperature sensor (not shown) that detects the temperature of the first heating port 1, the second heating port 2, and the third heating port 3. The input power is set to the first value until the temperature of the second heating port 2 and the third heating port 3 reaches the first temperature, and the first heating port 1, the second heating port 2, After the temperature of the third heating port 3 reaches the first temperature, the information indicates an operation such as setting the input power to the second value.

  When the load placed on each of the heating units 11 to 13 is the power receiving device 60, the calculation unit 451 performs control for performing non-contact power feeding to the power receiving device 60 and performs the operation of the power receiving device 60. If controllable, a control signal for controlling the power receiving device 60 is generated and transmitted to the power receiving device 60 via the communication unit 6.

  The communication cycle detection unit 452 determines whether or not the wireless communication executed by the communication unit 6 has periodicity, and calculates the cycle when the wireless communication has periodicity.

  FIG. 9 is a flowchart illustrating an example of a load determination processing procedure according to the present embodiment. The induction heating cooker 100 receives an operation command for instructing the start of the operation when the operator operates the operation unit 40. When the operation command is input (step S1), the induction heating cooker 100 first supplies power to the load so that the power receiving device 60 can perform wireless communication (step S2). Specifically, when notified from the operation unit 40 that an operation command has been input, the calculation unit 451 inputs the predetermined value as a target power to the drive control unit 453 for a predetermined period. To do. The drive control unit 453 generates a control signal for controlling on / off of each switching element of the inverter circuit 23 of the drive circuit 51 based on the target power, and inputs the control signal to the inverter circuit 23.

  The induction heating cooker 100 determines whether or not there is wireless communication from the load (step S3). Specifically, the calculation unit 451 determines whether or not a wireless signal storing information indicating that the load is a power receiving device and information related to necessary power is received from the load via the communication unit 6. When there is wireless communication from the load (Yes in step S3), the calculation unit 451 determines that the load is a power receiving device (step S4), and the communication content from the power receiving device 60, that is, the necessary power received from the power receiving device 60. The operation of the heating coil with the electric power according to the information regarding is started (step S5), and the load determination process is terminated.

  In step S <b> 5, specifically, the calculation unit 451 determines a target power based on information on necessary power, and instructs the drive control unit 453 about the target power. The drive control unit 453 turns on each switching element of the inverter circuit 23 of the drive circuit 51 based on the target power, the detected current value by the input current detecting unit 25a, and the detected current value by the output current detecting unit 25b. A control signal for controlling / off is generated and input to the inverter circuit 23.

  On the other hand, when there is no wireless communication from the load (No at Step S3), the calculation unit 451 determines whether or not the load determination period has elapsed (Step S6). Specifically, the calculation unit 451 compares the elapsed time from the start of the load determination operation, that is, the elapsed time from the start of supplying power in step S2 with a predetermined load determination period, and the elapsed time is determined as a load determination. Determine whether the period has been reached. When the load determination period has not elapsed (No at Step S6), the calculation unit 451 returns to Step S2. When the load determination period has elapsed (Yes in step S6), the calculation unit 451 determines that the load is the article to be heated 5 (step S7), and the heating coil with heating power based on the input made via the operation unit 40 Is started (step S8), and the load determination process is terminated. As described above, upon receiving the operation start command, the induction heating cooker 100 according to the present embodiment controls the drive circuit 51 to output a predetermined power for a certain period, and during the certain period. When a wireless signal indicating that the device is a power receiving device is received, the load corresponding to the first heating unit 11 is determined to be the power receiving device, and a wireless signal indicating that the device is a power receiving device for a certain period of time. When not receiving, it determines with the load corresponding to the 1st heating part 11 being a to-be-heated object.

  In the present embodiment, the control unit 45 performs control to change the high-frequency power supplied by the drive unit 50 during the period in which the communication unit 6 and the power receiving device 60 perform wireless communication after starting non-contact power feeding, that is, power change. Take control. Hereinafter, the power change control will be described.

  FIG. 10 is a diagram illustrating an example of a relationship between high-frequency power supplied from the drive circuit 51 to the first heating unit 11 and a period during which the communication unit 6 performs wireless communication. Hereinafter, although the 1st heating part 11 is demonstrated to an example, you may perform the same control also in the 2nd heating part 12 and the 3rd heating part 13. FIG. In FIG. 10, the current input to the first heating unit 11 is shown in the upper stage, and the state of wireless communication is shown in the lower stage. Further, the upper dotted line in FIG. 10 indicates the output command value amplitude which is the current amplitude corresponding to the original command value. In the example illustrated in FIG. 10, the calculation unit 451 of the control unit 45 stops the high-frequency power supplied by the drive circuit 51 during the period in which the communication unit 6 performs wireless communication, that is, the first period. Specifically, for example, the calculation unit 451 outputs 0 to the drive control unit 453 as target power that is a control target value different from the original command value. Thereby, the leakage magnetic flux which generate | occur | produces in the 1st heating part 11 is decreased, and the interference by the leakage magnetic flux to a radio signal is suppressed. Note that if a time during which the operation can be continued with an internal battery (not shown) included in the power receiving device 60 from which the supply of high-frequency power is stopped has passed, the power receiving device 60 cannot continue communication. Therefore, the period during which the high-frequency power is stopped is the time during which the communication unit 64 of the power receiving device 60 can continue the wireless communication with the communication unit 6, that is, the power receiving device 60 performs the communication operation using an internal battery or the like. It is assumed that the time is shorter than possible.

  In addition, when the power receiving device 60 cannot transmit all the contents of the wireless communication, that is, the necessary power, during the stop time of the high frequency power, the power receiving device 60 is set in advance so that the information is divided and transmitted in multiple times. Make up. Alternatively, the calculation unit 451 may instruct the power receiving device 60 to divide the information and transmit it in multiple times via the communication unit 6. Here, the period in which the communication unit 6 performs wireless communication is a period in which the communication unit 6 performs transmission to the power receiving device 60 and a period in which reception is performed from the power receiving device 60. The calculation unit 451 can obtain from the communication unit 6 the period during which transmission to the power receiving device 60 is performed. The period for receiving from the power receiving device 60 is a period estimated based on the periodicity by the communication cycle detecting unit 452 as described later, or a period in which the communication unit 6 detects a radio signal transmitted from the power receiving device 60. It is.

  FIG. 11 is a diagram illustrating another example of the relationship between the high-frequency power supplied from the drive circuit 51 to the first heating unit 11 and the period during which the communication unit 6 performs wireless communication. In FIG. 11, the current input to the first heating unit 11 is shown in the upper stage, and the state of wireless communication is shown in the lower stage. Further, the upper dotted line in FIG. 11 indicates the output command value amplitude, which is the current command amplitude determined based on the original command value, that is, information on the required power of the power receiving device 60. In the example illustrated in FIG. 11, high-frequency power supplied by the drive circuit 51 is suppressed in a period during which the communication unit 6 performs wireless communication, that is, a first period. That is, in the example shown in FIG. 11, in the period in which the communication unit 6 executes wireless communication, that is, the first period, the high frequency power supplied by the drive circuit 51 is in the period in which wireless communication is not performed, that is, the second period. Smaller than that.

  Specifically, for example, the calculation unit 451 designates a small power to the drive control unit 453 as compared to a period during which wireless communication is not performed as an instruction value instead of the original command value. Thereby, the leakage magnetic flux generated in the first heating unit 11 is reduced, the interference due to the leakage magnetic flux to the radio signal is suppressed, and the high-frequency power to be supplied is stopped as shown in FIG. Thus, output power closer to the original command value can be obtained. The original command value is a command value before suppressing the output power in order to reduce the leakage magnetic flux, and is a command value calculated based on information related to the required power of the power receiving device 60.

The communication cycle detection unit 452 determines whether or not the wireless communication between the communication unit 6 and the power receiving device 60 has periodicity based on signals indicating the start and end of communication output from the communication unit 6. Note that, when the communication unit 6 is wirelessly connected to the power receiving device 60, the communication unit 6 outputs a signal indicating the start and end of communication to the communication cycle detection unit 452 when the communication with the power receiving device 60 starts and ends. The communication cycle detection unit 452 stores, for example, communication start and end times based on signals indicating communication start and end, and calculates a time difference Δt ₁ between the communication start times from the past communication start times. . Communication cycle detector 452 determines that calculates a plurality of Delta] t _1, and statistically processes the plurality of Delta] t _1, when the standard deviation or variance is below the threshold a predetermined periodicity there . The method for determining the presence or absence of periodicity is not limited to this example.

When the communication cycle detection unit 452 determines that the wireless communication between the communication unit 6 and the power receiving device 60 has periodicity, the cycle of the wireless communication between the communication unit 6 and the power receiving device 60 based on a plurality of Δt _1. Is calculated. Also, the time from the communication start time to the end is calculated, and based on the calculated value, the communication continuation time, that is, the period during which wireless communication is executed, is calculated. Within the cycle, a period excluding a period for performing wireless communication is referred to as a period for not performing wireless communication, or a wireless communication suspension period. Through the above processing, the communication cycle detection unit 452 can grasp the period during which wireless communication is executed and the suspension period of wireless communication. The communication cycle detection unit 452 predicts the start time of the period during which wireless communication is executed and the wireless communication suspension period, and notifies the calculation unit 451 of the start time.

  When the calculation unit 451 is notified of the period for executing the predicted wireless communication, the calculation unit 451 is described above with the start of the period for executing the notified wireless communication or immediately before the start of the period for executing the notified wireless communication. As described above, control for changing the target power output to the drive control unit 453 is performed. When the instruction value output to the drive control unit 453 is changed after the execution of the wireless communication is detected, the leakage magnetic flux generated in the first heating unit 11 from the start of the wireless communication until the target power is changed. There is a possibility of interference with radio signals. In the present embodiment, the first heating unit 11 generates the period of the wireless communication from the beginning in the period of executing the wireless communication by obtaining the period of the wireless communication, predicting the period of executing the wireless communication and performing the above control. Since leakage magnetic flux can be suppressed, communication quality can be improved.

  Note that when the communication unit 6 and the power receiving device 60 determine that the wireless communication is not periodic, the communication cycle detection unit 452 notifies the calculation unit 451 of the fact and detects the start and end of the wireless communication. Each time, the calculation unit 451 is notified of the start and end of wireless communication. The calculation unit 451 changes the target power output to the drive control unit 453 when the start of wireless communication is notified, and the target power output to the drive control unit 453 when the end of wireless communication is notified. Return to the value, that is, the target power before the change.

  FIG. 12 is a flowchart illustrating an example of a power change control procedure according to the first embodiment. FIG. 12 is a flowchart in the case of executing a process of changing power during communication with the power receiving device 60. First, when the control unit 45 of the induction heating cooker 100 is instructed to start the non-contact power supply by the operation of the operation unit 40 or the control signal from the power receiving device 60, the control unit 45 starts the non-contact power supply. It is determined whether or not an operation stop command, which is a command to stop the operation of non-contact power feeding, is input based on an operation of the operation unit 40 or a control signal from the power receiving device 60 (step S11). When the operation stop command is input (step S11 Yes), the control unit 45 ends the non-contact power supply (step S12).

  When the operation stop command is not input (No at Step S11), the induction heating cooker 100 continues the non-contact power feeding operation (Step S13). Specifically, the control unit 45 generates target power based on a control signal from the power receiving device 60 and instructs the drive circuit 51, and the drive circuit 51 inputs high frequency power to the first heating unit 11. . In the initial state, the target power is a command value.

  Further, during the heating operation, the control unit 45 detects the period of wireless communication performed by the communication unit 6 and the power receiving device 60 (step S14). Specifically, when the communication cycle detection unit 452 determines whether or not the wireless communication performed by the communication unit 6 and the power receiving device 60 has periodicity, and determines that there is periodicity, the calculation of the cycle is performed. The process and the prediction process of the period for executing the wireless communication are performed.

  When it is determined that the wireless communication performed by the communication unit 6 and the power receiving device 60 has periodicity (Yes in step S15), the control unit 45 determines the first heating unit based on the prediction of the period for performing the wireless communication. Control to change the high-frequency power supplied to 11 is performed (step S16) and the process returns to step S11. Specifically, as described above, the control unit 45 suppresses the high-frequency power supplied to the first heating unit 11 during the wireless communication period based on the prediction of the period during which the wireless communication is performed, and wirelessly In the communication suspension period, control for restoring the high-frequency power is performed.

  When it is determined that the wireless communication performed by the communication unit 6 and the power receiving device 60 has no periodicity (No in step S15), the control unit 45 detects the execution of the wireless communication and then supplies it to the first heating unit 11. Control to change the high frequency power to be performed is performed (step S17), and the process returns to step S11. As described above, the control unit 45 may perform the same control for the second heating unit 12 and the third heating unit 13, respectively.

  In addition, the control unit 45 may generate a control signal for designating a cycle for performing wireless communication for the power receiving device 60 and transmit the control signal to the power receiving device 60 via the communication unit 6. For example, when the control unit 45 receives information indicating the type of the power receiving device 60 from the power receiving device 60 and determines that frequent communication is not necessary based on the type of the power receiving device 60, the control unit 45 sets the number of times of wireless communication. Use less than the standard value. Thereby, since the frequency | count which varies the high frequency electric power which the drive circuit 51 supplies can be decreased, electric power can be supplied more correctly.

With the above processing, the drive circuit 51 can suppress or stop the high-frequency power supplied to the first heating unit 11 during a period in which the communication unit 6 and the power receiving device 60 do not perform wireless communication. When performing control to suppress or stop output power to the first heating unit 11 when performing wireless communication, the average output power is smaller than the command value, but when wireless communication is periodic, the wireless communication is suspended. If the high-frequency power supplied by the drive circuit 51 during the period is increased from the value corresponding to the original command value, the average output power closer to the original command value can be supplied to the first heating unit 11. For example, if the original command value and X, a period T _a which executes wireless communication, if rest period wireless communication is T _b, the control unit 45, the target power duration for executing the radio communication Is X−ΔX, and the target power of the wireless communication suspension period is X + ΔX × T _a / T _b .

  Moreover, the induction heating cooking appliance 100 may implement the process shown in FIG. 13 instead of the load determination process shown in FIG. FIG. 13 is a flowchart illustrating another example of the load determination processing procedure according to the present embodiment. In the process illustrated in FIG. 13, when a wireless signal indicating that the load is a power receiving device is received from the power receiving device 60 during the load determination period, the load is determined to be the power receiving device, and information on necessary power is received. Even when the wireless communication for this purpose fails, the load determination operation is continued until the information regarding the required power can be correctly received from the power receiving device 60. In other words, after receiving a radio signal indicating that the device is a power receiving device for a certain period of time, if reception of control information for controlling the power receiving device, i.e., information on necessary power, fails, heating is continued until the certain time period elapses. The determination that the load corresponding to the unit is a power receiving device is maintained, and reception of the control information is awaited. Thereby, in the load determination, it is possible to prevent the power receiving device from being determined as an object to be heated, and to acquire information necessary for appropriately operating the power receiving device.

  Step S21 and step S22 shown in FIG. 13 are the same as step S1 and step S2 of FIG. After step S22, when the calculation part 451 of the induction heating cooking appliance 100 receives the signal which shows that it is a power receiving apparatus from the power receiving apparatus 60 (step S23 Yes), it determines with a load being a power receiving apparatus (step S24). ). The calculation unit 451 of the induction heating cooker 100 determines whether or not the control content of the power receiving device 60 has been successfully received, that is, whether or not all the information regarding the required power has been normally received (step S25).

  When the control content of the power receiving device 60 has been successfully received (step S25 Yes), the process proceeds to step S26. When reception of the control content of the power receiving device 60 fails (No in step S25), the arithmetic unit 451 returns to step S22. Step S26 is the same as step S5 of FIG. In Step S23, when a signal indicating that the device is a power receiving device is not received from the power receiving device 60 (No in Step S23), the process proceeds to Step S27. Step S27, step S28, and step S29 are the same as step S6, step S7, and step S8 of FIG.

  In addition, when the wireless communication with the power receiving device 60 fails during the non-contact power feeding operation period, the induction heating cooker 100 determines that the load is the power receiving device until a predetermined communication limit period elapses. While recognizing, the contactless power supply operation may be continued, and if the wireless communication fails continuously during the communication limit period, control at the time of communication failure such as stopping the contactless power supply operation may be performed. As a result, the induction heating cooker 100 is prevented from continuing to operate while the operating state of the power receiving device 60 is unclear, and non-contact power feeding can be performed more safely. In addition, the operation performed when wireless communication fails continuously during the communication limit period is not limited to the example of stopping the non-contact power supply operation, and the output at the time of wireless communication returns to the load determination operation at the time of activation. An operation such as making the period for changing the period longer than the set value may be performed.

  FIG. 14 is a flowchart illustrating an example of a non-contact power supply operation procedure including determination using the communication limit period. Step S31, step S32, and step S33 are the same as step S11, step S12, and step S13 of FIG. After step S33, the calculation unit 451 changes the output and performs wireless communication (step S34). That is, as described above, the arithmetic unit 451 stops the high-frequency power or reduces the output as the operation during the period of executing the wireless communication. The computing unit 451 determines whether or not the wireless communication with the power receiving device 60 during the period of executing the wireless communication is successful (step S35).

  When the wireless communication with the power receiving device 60 is successful (step S35 Yes), the calculation unit 451 executes control according to the control content received from the power receiving device 60, that is, the information regarding the necessary power received from the power receiving device 60. (Step S36), the process returns to Step S33. When the wireless communication with the power receiving device 60 is not successful (No at Step S35), it is determined whether the communication limit period has passed without successful wireless communication, that is, the period when the wireless communication is not successful is the communication limit. It is determined whether or not the period has been reached (step S37). If the communication limit period has passed without successful wireless communication (Yes in step S37), the process proceeds to step S32. When the period during which wireless communication is not successful has not reached the communication limit period (No in step S37), the calculation unit 451 maintains the current control content (step S38) and returns to step S33. As described above, in the example of FIG. 13, when the induction heating cooker 100 continuously fails in wireless communication with the power receiving apparatus during the communication limit period, the control at the time of communication failure determined in advance is performed. I do. In FIG. 14, the case where the non-contact power supply operation is stopped is described as an example of the control when the wireless communication fails continuously for the communication limit period, but as described above, the communication limit period continues. The operation when wireless communication fails is not limited to stopping the non-contact power supply operation.

  For example, the following method is used to determine whether the wireless communication is correctly performed, that is, whether the wireless communication is successful. When a wireless signal is transmitted from the power receiving device 60 to the communication unit 6, the communication unit 6 transmits a signal for confirming the content of the received control signal to the power receiving device 60. Then, the power receiving device 60 transmits again a signal related to whether or not the control signal is correctly received by the communication unit 6 from the received signal to the communication unit 6. Thereby, the communication part 6 can confirm whether radio | wireless communication is performed correctly. The communication unit 6 notifies the control unit 45 of information indicating whether or not wireless communication is accurately performed. Based on this notification, the control unit 45 can determine whether or not wireless communication is accurately performed. Or as a reverse case, when a control signal is transmitted from the communication unit 6 to the power receiving device 60, a signal for confirming the content of the received control signal is transmitted from the power receiving device 60 to the communication unit 6. Then, there is a method in which the communication unit 6 confirms from the received signal whether the control signal is correctly received by the power receiving device 60. Alternatively, both of these methods may be implemented.

  As another method for determining that wireless communication is being performed accurately, the format of a control signal for wireless communication between the power receiving device 60 and the communication unit 6 is determined in advance, and the received control signal is in the correct format. There is also a method of determining by whether or not.

  In addition, another method for determining whether the wireless communication is correctly performed is that a control signal communicated between the power receiving device 60 and the communication unit 6 has a wireless communication success mark at least at the start and end points. There is also a method of making a determination based on whether or not the control signal has been received including all the marks. The method for determining that wireless communication is accurately performed is not limited to the above example, and any method may be used.

  As described above, in induction heating cooker 100 of the present embodiment, it is determined whether or not the load is power receiving device 60, and wireless communication with power receiving device 60 is performed during a period in which wireless communication with power receiving device 60 is performed. The electric power supplied to the 1st heating part 11 was made small from the period which is not performed. Thereby, the induction heating cooker 100 can suppress interference due to leakage magnetic flux with respect to a radio signal transmitted to or received from the power receiving device 60.

Embodiment 2. FIG.
FIG. 15: is a figure which shows the structural example of the control part 45a of the induction heating cooking appliance 200 concerning Embodiment 2 of this invention. The induction heating cooker 200 of the present embodiment is the same as the induction heating cooker 100 of the first embodiment, except that it includes a control unit 45a instead of the control unit 45 of the first embodiment. The control unit 45a includes a calculation unit 451a and a drive control unit 453 similar to that in the first embodiment. Components having the same functions as those in the first embodiment are denoted by the same reference numerals as those in the first embodiment, and redundant description is omitted. Hereinafter, differences from the first embodiment will be described.

  The magnitude of the leakage magnetic flux generated from the first heating unit 11 pulsates at a frequency twice the frequency of the AC power supplied from the AC power supply 21, but in this embodiment, near the valley at the time of this pulsation. Control is performed to perform wireless communication during the period.

  FIG. 16 is a diagram illustrating an example of a relationship between the high-frequency power supplied by the drive circuit 51 and the period during which the communication unit 6 performs wireless communication in the second embodiment. When the output voltage of the DC power supply circuit 22 is not completely smoothed, the current supplied from the drive circuit 51 to the first heating unit 11 pulsates at twice the frequency of the AC power supplied from the AC power supply 21. The magnitude of the leakage magnetic flux generated in the first heating unit 11 also pulsates at twice the frequency of the AC power supplied from the AC power supply 21. Hereinafter, a frequency twice the frequency of the AC power supplied from the AC power source 21 is referred to as a power source double frequency.

  The induction heating cooker 200 measures the current of the first heating unit 11 by the output current detection unit 25b, and the current peak of the first heating unit 11 is a predetermined current due to the pulsation at the double frequency of the power source. Wireless communication is performed in a period that falls within a range, that is, a period in which the current amplitude is equal to or less than a predetermined threshold. The current peak of the first heating unit 11 indicates the maximum value within each switching period of the current output to the first heating unit 11. As shown in FIG. 16, the current peak pulsates at twice the power supply frequency. By performing wireless communication in a period in which the current peak of the first heating unit 11 is equal to or less than the threshold value, wireless communication can be performed in a period in which the leakage magnetic flux generated in the first heating unit 11 is small. Therefore, it is possible to suppress the leakage magnetic flux generated in the first heating unit 11 from interfering with the radio signal and improve the quality of the radio communication. The maximum value of the current peak of the first heating unit 11 is larger as the command value of the output power is larger, but by setting the period for performing wireless communication as the period in which the current peak of the first heating unit 11 is in the current range, Regardless of the output power command value, wireless communication can be performed in a period in which the leakage magnetic flux generated in the first heating unit 11 is small.

  FIG. 17 is a flowchart illustrating an example of a communication control procedure according to the present embodiment. Step S11, step S12 and step S13 are the same as step S11, step S12 and step S13 of the first embodiment, respectively. When the non-contact power feeding operation is continued, the calculation unit 451a is input to the current peak of the first heating unit 11, that is, the first heating unit 11 based on the detected current value by the output current detection unit 25b. The peak value of the current to be detected is detected (step S41). The calculation unit 451a determines whether or not the current peak of the first heating unit 11 exceeds the threshold value (step S42), and if it exceeds the threshold value (step S42 Yes), the calculation unit 451a determines that wireless communication cannot be performed. (Step S43), the communication unit 6 is notified of the prohibition of wireless communication, and the process returns to Step S11. When the current peak of the first heating unit 11 is equal to or less than the threshold (No in step S42), the calculation unit 451a determines that wireless communication can be performed (step S44), notifies the communication unit 6 of permission for wireless communication, and step Return to S11.

  It is desirable to obtain the current peak of the first heating unit 11 by measuring the current directly output to the first heating unit 11. However, instead of measuring the current of the first heating unit 11, as a means for estimating the current peak of the first heating unit 11, the input current is detected in advance using the input current detected by the input current detection unit 25 a. A means for estimating from a period in which the current range is set may be used. For example, instead of the period in which the current output to the first heating unit 11 is equal to or less than the threshold value, a period in which the input current detected by the input current detection unit 25a is in a predetermined current range may be used.

  Further, as another means for estimating the period during which the current peak of the first heating unit 11 is equal to or less than the threshold value, the input voltage of the DC power supply circuit 22 or the DC power supply circuit 22 is obtained using a voltage detection unit such as a voltage sensor. The output voltage may be measured, and a means for estimating the period during which the current peak of the first heating unit 11 is equal to or less than the threshold may be used using the period during which the input voltage or the output voltage falls within a predetermined voltage range. For example, a period in which the input voltage or the output voltage is in a predetermined voltage range may be used instead of the period in which the current output to the first heating unit 11 is equal to or less than the threshold value.

  In addition, as another means for estimating the period during which the current peak of the first heating unit 11 is equal to or less than the threshold value, the magnetic flux generated in the first heating unit 11 is measured using a magnetic flux detection unit such as a Hall sensor. A means for estimating a period during which the current peak of the first heating unit 11 is equal to or less than the threshold may be used using a period during which the magnetic flux is equal to or less than a predetermined threshold. In this case, it is desirable to arrange the Hall sensor near the communication unit 6. For example, instead of the period in which the current output to the first heating unit 11 is equal to or less than the threshold, a period in which the magnetic flux is equal to or less than the threshold may be used.

  As described above, in the present embodiment, communication is permitted in a period in which the current peak of the first heating unit 11 is equal to or less than the threshold value, and communication is disabled when the current peak of the first heating unit 11 is greater than the threshold value. I tried to do it. For this reason, the induction heating cooker 200 can suppress interference due to leakage magnetic flux with respect to a radio signal transmitted to or received from the power receiving device 60.

  As described above, in the first embodiment, the period for performing wireless communication and the suspension period for wireless communication are predicted, and in the period for performing wireless communication, the power output from the drive circuit 51 to the first heating unit 11 is Control is performed so that the electric power is smaller than the power output from the drive circuit 51 to the first heating unit 11 during the wireless communication suspension period. On the other hand, in the second embodiment, control is performed so that communication is permitted in a period in which the current peak of the first heating unit 11 is equal to or less than the threshold, and communication is disabled when the current peak of the first heating unit 11 is greater than the threshold. I did it. In the second embodiment, the current peak of the first heating unit 11 is smaller in a period during which communication is permitted, that is, a period in which wireless communication is executed, than in a period in which communication is disabled, that is, a wireless communication suspension period. For this reason, also in the second embodiment, the power output from the drive circuit 51 to the first heating unit 11 during the period in which wireless communication is performed is from the drive circuit 51 to the first heating unit 11 during the wireless communication pause period. Less than the power output to Note that the communication control function described in the second embodiment is added to the induction heating cooker 100 of the first embodiment, and both the operation of the first embodiment and the operation of the second embodiment are performed. Also good.

  Further, it is assumed that there are a plurality of heating units, a plurality of driving circuits corresponding to the heating units, respectively, and the driving circuits are operating simultaneously. In this case, when the communication unit 6 and the power receiving device 60 perform wireless communication, the control unit 45 of the first embodiment performs control to change the high-frequency power supplied to some or all of the first heating units 11. By doing so, the leakage magnetic flux generated in some or all of the heating units is reduced. Or the control part 45a of Embodiment 2 reduces the leakage magnetic flux which generate | occur | produces in a part or all the heating parts by performing the communication control mentioned above about the one part or all the 1st heating parts 11. . Thereby, interference of the leakage magnetic flux generated in the heating unit to the radio signal can be suppressed.

  The configuration described in the above embodiment shows an example of the contents of the present invention, and can be combined with another known technique, and can be combined with other configurations without departing from the gist of the present invention. It is also possible to omit or change the part.

  DESCRIPTION OF SYMBOLS 1 1st heating port, 2nd heating port, 3rd heating port, 4 Top plate, 5 To-be-heated object, 6 Communication part, 11 1st heating part, 12 2nd heating part, 13th Three heating sections, 14 grill sections, 21 AC power supply, 22 DC power supply circuit, 22a diode bridge, 22b reactor, 22c smoothing capacitor, 23 inverter circuit, 23a, 23b, 23e, 23f IGBT, 23c, 23d, 23g, 23h diode , 24 resonant capacitor, 25a input current detection unit, 25b output current detection unit, 40a, 40b, 40c operation unit, 41a, 41b, 41c display unit, 43 display operation unit, 45, 45a control unit, 50 drive unit, 51 drive Circuit, 60 power receiving device, 61 coil, 62 conversion circuit, 63 load, 64 communication unit, 100, 200 induction heating cooker, 51,451a calculation unit, 452 communication cycle detection unit, 453 drive controller.

Claims (12)

An induction heating cooker capable of performing wireless communication with a power receiving device, the induction heating cooker is used for non-contact power feeding to the power receiving device and heating of an object to be heated,
A top plate on which the power receiving device or the object to be heated is placed;
A heating unit that is arranged below the top plate and performs non-contact power feeding to the power receiving device, and induction heating the object to be heated;
A drive circuit for outputting a current to the heating unit;
In the first period, the current output from the drive circuit is controlled to be a value smaller than the current in the second period, the period of wireless communication with the power receiving device is determined, and the power receiving device A control unit that changes the first period and the second period based on the period when there is periodicity in the wireless communication between,
With
The induction heating cooker, wherein the first period is a period for performing wireless communication with the power receiving apparatus, and the second period is a period for not performing wireless communication with the power receiving apparatus.   The control unit determines a cycle of wireless communication with the power receiving device based on at least one of the cooking mode and the heating state, and sends a control signal to the power receiving device to instruct communication at the determined cycle. The induction heating cooker of Claim 1 which transmits.   The induction heating cooker according to claim 1 or 2, wherein the control unit performs control so that a current output from the drive circuit in the second period is larger than a command value. The drive circuit includes an inverter circuit;
An output current detection unit for detecting a current output from the drive circuit to the heating unit;
A period in which the maximum value of the current detected by the output current detection unit within the switching cycle of the inverter circuit is equal to or less than a threshold is set as a period for performing wireless communication with the power receiving device, and the maximum value exceeds the threshold A control unit for setting a period as the second period;
An induction heating cooker according to claim 1 comprising: The drive circuit includes an inverter circuit;
An input current detector for detecting a current input to the drive circuit;
A period in which the current detected by the input current detection unit falls within a predetermined current range is set as the first period, and a period in which the current exceeds a predetermined current range is set as the second period. A control unit,
An induction heating cooker according to claim 1 comprising:   The control unit includes a drive circuit, a DC power supply circuit and an inverter circuit connected to the DC power supply circuit, and a voltage input to the DC power supply circuit or a voltage output from the DC power supply circuit is predetermined. A period within the voltage range is set as the first period, and a period during which the voltage input to the DC power supply circuit or the voltage output from the DC power supply circuit exceeds a predetermined voltage range is set as the second period. The induction heating cooker of Claim 1 set as.   The said control part sets the period when the magnetic flux which generate | occur | produces in the said heating part becomes below a threshold value as said 1st period, and sets the period when the magnetic flux which generate | occur | produces in the said heating part exceeds a threshold value as said 2nd period. Item 2. An induction heating cooker according to item 1. A plurality of the heating unit and the drive circuit are provided,
2. The induction heating cooker according to claim 1, wherein at least one of the plurality of drive circuits outputs a current smaller than a current output in the second period in the first period.   When the control unit receives an operation start command, the control unit controls the drive circuit to output a predetermined power for a predetermined period, and transmits a radio signal indicating the power receiving apparatus during the predetermined period. If received, it is determined that the load corresponding to the heating unit is the power receiving device, and if the wireless signal indicating that the load is the power receiving device is not received during the predetermined period, the load corresponds to the heating unit. The induction heating cooker according to any one of claims 1 to 7, wherein the load to be determined is an object to be heated.   When the control unit fails to receive control information for controlling the power receiving device after receiving a radio signal indicating the power receiving device during the certain period, until the certain period elapses. The induction heating cooker according to claim 9, which maintains a determination that a load corresponding to the heating unit is the power receiving device and waits for reception of the control information.   When the wireless communication with the power receiving device continuously fails during a predetermined communication limit period during the non-contact power supply operation, the control unit performs a predetermined communication failure control. The induction heating cooker according to claim 9 or 10. A power receiving device;
The induction heating cooker according to any one of claims 1 to 11, wherein non-contact power feeding is performed on the power receiving device;
A contactless power supply system.

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