JP2010086740A - Induction heating cooking appliance - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an induction heating cooking appliance capable of operating together a plurality of heating coils for heating a large pan such as an oval shaped pan without deviation of heating distribution and capable of determining whether identical pans are mounted on top plates or different pans are mounted on the top plates. <P>SOLUTION: The induction heating cooking appliance is provided with an operation part with a third input part for driving a first heating coil and a second heating coil at the same time, in addition to the first input part for driving at least the first heating coil independently and the second input part for driving the second heating coil independently. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an induction heating cooker that can heat one large pot using a plurality of heating units.

Conventionally, in this type of induction heating cooker, one cooking container is placed on a top plate facing one heating coil and heated by one heating coil (see, for example, Patent Document 1). .
JP 2007-18786 A

  However, in the conventional configuration, in the case of a large pan having an oval shape or the like, the size of the pan bottom is much larger than the outer diameter size of the heating coil, so one large pan is heated by one heating coil. Then, there was a problem that the heating distribution was biased and the cooking performance was impaired.

  As a method of heating a large pan so that the heating distribution is not biased, it is conceivable to heat one pan with a plurality of heating coils. However, when a heating coil for heating a large pan is newly provided, a space for newly arranging the heating coil is required, which makes it difficult to cool the heating coil or causes an expensive configuration. Become. In addition, it must be determined that one pan is placed on the top plate facing the plurality of heating coils. However, since the conventional induction heating cooker determines for each heating coil whether the pan is placed on the top plate, the pan placed on the top plate facing the plurality of heating coils It was a problem that it was not possible to detect whether or not was a separate pan or a single pan.

  The present invention solves the above-described problems, and is a conventionally used heating coil for heating a large pan having a shape such as an oval shape with a simple configuration so that the heating distribution is not biased. The two heating coils are operated as if they were heated by one heating coil, and the same pan is placed on the top plate facing the plurality of heating coils or separately. It is an object of the present invention to provide an induction heating cooker that can determine whether or not a pan is placed.

  An induction heating cooker according to the present invention includes a top plate on which a cooking container is placed, and first and second heating coils that are disposed below the top plate and that have different circular centers for heating the cooking container. A control unit that controls heating of the first and second heating coils, a first inverter that is controlled by the control unit and supplies power to the first heating coil, and is controlled by the control unit A second inverter that supplies electric power to the second heating coil; and an operation unit that instructs an operation state to the control unit, wherein the operation unit operates at least the first heating coil independently. A second input unit that operates the input unit and the second heating coil independently; and a third input unit that operates the first heating coil and the second heating coil simultaneously.

The induction heating cooker includes first and second pan placement discriminating units for discriminating whether or not the cooking container is placed on the top plate facing each of the first and second heating coils; You may have a 3rd pan mounting determination part which discriminate | determines whether the cooking container is mounted on the top plate which opposes between the 1st and 2nd heating coils. In this case, when the control unit determines that all of the first pot mounting determination unit, the second pot mounting determination unit, and the third pot mounting determination unit are mounted, It may be possible to accept commands from the first to third input units.

  In this case, when the control unit receives a command from the third input unit, the control unit may prohibit reception from the first and second input units.

  In this case, when the control unit receives a command from the first or second input unit, the control unit may prohibit the reception from the third input unit.

  The controller may link the operation of the first inverter and the operation of the second inverter when one cooking container is heated by both the first heating coil and the second heating coil. The control unit includes the first inverter and the second inverter so that at least one of the timing of the heating start, the heating stop, and the thermal power change by the first heating coil and the second heating coil coincides. The operations of the inverters may be linked. The first inverter and the second inverter may each supply power so that the ratio of the power amount of the first heating coil and the power amount of the second heating coil is constant.

  The third pan placement discriminating unit is a light that detects disturbance light incident from the top plate at a position below the top plate and opposed between the first heating coil and the second heating coil. You may have a detection part. In this case, when the light detection unit detects disturbance light, the third pan placement determination unit places the cooking container on the top plate facing between the first heating coil and the second heating coil. When it is determined that the light detector is not detecting disturbance light, a cooking container is placed on the opposing top plate between the first heating coil and the second heating coil. You may judge that

  The third pan placement determination unit has a temperature detection unit that detects the temperature of the cooking container at a position below the top plate and between the first heating coil and the second heating coil. May be. In this case, the third pan placement discriminating unit is a top plate facing between the first heating coil and the second heating coil when the temperature detecting unit detects a predetermined amount of temperature rise within a predetermined time. It may be determined that the cooking container is placed on the top.

  The second pan placement determination unit has a light detection unit that detects disturbance light incident from the top plate at a position below the top plate and facing the inner side of the outer edge of the second heating coil. May be. In this case, when the light detection unit detects disturbance light, the second pan placement determination unit determines that the cooking container is not placed on the top plate facing the second heating coil, and the light When the detector does not detect disturbance light, it may be determined that the cooking container is placed on the top plate facing the second heating coil.

  The second pan placement determining unit may include a temperature detection unit that detects the temperature of the cooking container at a position below the top plate and facing the inner side of the outer edge of the second heating coil. In this case, the second pan placement discriminating unit places the cooking container on the top plate facing the second heating coil when the temperature detection unit detects a predetermined amount of temperature rise within a predetermined time. You may judge that

The first pan placement discriminating unit detects the electrical characteristics of the cooking container placed on the top plate facing the first heating coil, and the second pan placement discriminating unit performs the second heating. You may detect the electrical property of the cooking vessel mounted on the top plate facing a coil. In this case, the control unit determines that all of the first pot mounting determination unit, the second pot mounting determination unit, and the third pot mounting determination unit are mounted, and the first When the electrical characteristics detected from the 1 pan mounting discriminating unit and the second pan mounting discriminating unit are the same, the same on the top plate facing the first heating coil and the second heating coil It may be determined that the cooking container is placed.

  The control unit may control the operating frequency of the first inverter and the second inverter to be the same.

  When the control unit determines that all of the first pot mounting determination unit, the second pot mounting determination unit, and the third pot mounting determination unit are mounted with the cooking container, You may display that the instruction | command from the 3rd input part was attained.

  The induction heating cooker of the present invention includes a first input unit that causes the operation unit to operate at least the first heating coil alone and a second input unit that operates the second heating coil independently. A third input unit that operates the heating coil and the second heating coil at the same time is newly provided, and the first heating coil and the second heating coil are operated simultaneously, so that a large pan can be obtained with one heating coil. Can be operated as if heated. Therefore, for example, when it is determined that one large pan is placed on the top plate facing the plurality of heating coils, the plurality of heating coils can be driven in cooperation. As a result, the heating distribution is not biased, and one large pot can be heated without impairing the cooking performance.

  Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1)
FIG. 1 shows a configuration diagram of an induction heating cooker according to a first embodiment of the present invention. The induction heating cooker according to the present embodiment includes a top plate 1 provided on the upper surface of the apparatus, a first heating coil 2a, a second heating coil 2b, and a third plate provided below the top plate 1. And a heating coil 2c. The top plate 1 is made of an electrical insulator such as glass and transmits light. A cooking container such as the pan 10 is placed on the top plate 1.

  FIG. 2 shows a top view of the top plate 1. As shown in FIG. 2, the first heating coil 2a, the second heating coil 2b, and the third heating coil 2c have different circular centers. The first heating coil 2a, the second heating coil 2b, and the third heating coil 2c generate a high-frequency magnetic field by being supplied with a high-frequency current, and heat the pan 10 placed on the top plate 1. To do.

  As shown in FIG. 1, the induction heating cooker further includes a first inverter 3a that supplies a high-frequency current to the first heating coil 2a, and a second inverter that supplies a high-frequency current to the second heating coil 2b. 3b, a third inverter 3c that supplies a high-frequency current to the third heating coil 2c, and a controller 7 that controls the outputs of the first inverter 3a, the second inverter 3b, and the third inverter 3c. Prepare. On the user side of the top plate 1, there is provided an operation unit 5 composed of a plurality of switches to which control commands for instructing start / stop of heating and setting of thermal power are respectively assigned. The control unit 7 controls the outputs of the first inverter 3a, the second inverter 3b, and the third inverter 3c based on the control command input from the user via the operation unit 5, and starts heating. / Perform stop or thermal power setting.

The operation unit 5 includes at least a first input unit 8a that operates the first heating coil 2a alone, a second input unit 8b that operates the second heating coil 2b alone, and the first heating coil 2a.
When the pan is placed across the first heating coil 2a and the second heating coil 2b, the third input unit 8c is used. By inputting a control command, the first inverter 3a and the second inverter 3b are controlled in cooperation, and start / stop of heating, thermal power setting, and the like are performed.

  The induction heating cooker further includes a first pan placement discriminating section 4a for discriminating whether the pan 10 is placed on the top plate 1 facing the first heating coil 2a, and a second heating coil 2b. The pan 10 is placed on the top plate 1 facing the third heating coil 2c and the second pan placement discriminating portion 4b for discriminating whether the pan 10 is placed on the top plate 1 facing the top. And a fourth pan placement discriminating unit 4c that discriminates whether or not it is present. The first pan placement discriminating unit 4a detects the electrical characteristics of the pan 10 placed so as to face the first heating coil 2a, and thereby the top plate 1 facing the first heating coil 2a. It is discriminate | determined whether the pan 10 is mounted on top (refer FIG.3 and FIG.4). Similarly, the 2nd pan mounting discriminating part 4b and the 4th pan mounting discriminating part 4c are the pans 10 placed so as to oppose the second heating coil 2b and the third heating coil 2c, respectively. It is discriminated whether or not the pan 10 is placed on the top plate 1 facing the second heating coil 2b and the third heating coil 2c.

  When an instruction to start heating is input from the user, the control unit 7 applies a heating coil that is requested to start heating so that the pan placement determination units 4a to 4c can detect the electrical characteristics of the pan 10. The associated inverter is controlled to energize the heating coil. For example, when an instruction is input to start heating by the first heating coil 2a, the first pan placement determination unit 4a and the second pan placement determination unit 4b can detect the electrical characteristics of the pan 10. As described above, the first inverter 3a and the second inverter 3b are controlled so that the first heating coil 2a and the second heating coil 2b are sequentially energized.

  The induction heating cooker of the present embodiment further determines whether or not the pan 10 is placed on the top plate 1 facing between the first heating coil 2a and the second heating coil 2b. 3 pan mounting discriminating units 6. Since there is no heating coil between the 1st heating coil 2a and the 2nd heating coil 2b, the 3rd pot mounting discrimination | determination part 6 is based on the electrical property of the pot 10, and the pot 10 is mounted. Cannot be determined. Therefore, the third pan placement discriminating unit 6 discriminates whether the pan 10 is placed on the top plate 1 based on whether the incident of disturbance light is blocked by the pan 10. Therefore, the third pan placement determination unit 6 includes a light detection unit 61 that detects light passing through the top plate 1.

  With reference to FIG. 2, the mounting place of the light detection unit 61 will be described. The light detection unit 61 is provided below the top plate 1 and in a region 600 between the first heating coil 2a and the second heating coil 2b. When the pan is placed on the top plate 1 facing between the first heating coil 2a and the second heating coil 2b, since the incident of disturbance light is blocked by the pan, the light detection unit 61 is Does not detect ambient light. On the other hand, when a pan is not placed on the top plate 1 facing between the first heating coil 2 a and the second heating coil 2 b, disturbance light reaches the light detection unit 61. The third pan placement discriminating unit 6 is a top plate in which the pan faces between the first heating coil 2a and the second heating coil 2b based on whether or not the light detection unit 61 detects disturbance light. It is determined whether or not it is placed on the 1.

Hereinafter, in this specification, the fact that the pan is placed on the top plate 1 facing the first heating coil 2a is referred to as “the pan is placed on the first heating coil 2a”. Similarly, the fact that the pan 10 is placed on the top plate 1 facing the second heating coil 2b is referred to as “the pan is placed on the second heating coil 2b”. Furthermore, the fact that the pan 10 is placed on the top plate 1 facing between the first heating coil 2a and the second heating coil 2b indicates that the first heating coil 2a and the second heating coil 2b. A pan is placed between the two. "

  As illustrated in FIG. 2, the operation unit 5 includes operation units 5 a to 5 c provided in correspondence with the heating coils 2 a to 2 c, respectively. The first input unit 8a and the second input unit 8b are included in the operation units 5a to 5b provided corresponding to the first input unit 8a and the second input unit 8b, respectively, while the third input unit 8c is placed in any of the operation units 5a and 5b. Also good.

  In FIG. 3, the structure of the 1st pan mounting discrimination | determination part 4a is shown. The structure of the 2nd pan mounting discrimination | determination part 4b and the 4th pan mounting discrimination | determination part 4c is the same as the 1st pan mounting discrimination | determination part 4a. The first pan placement determination unit 4a includes an input current detection unit 41 that detects an input current Iin that flows from the AC power supply 11 to the first inverter 3a, and a coil that flows from the first inverter 3a to the first heating coil 2a. A coil current detection unit 42 for detecting the current IL, and a determination unit 43 for determining whether or not the pan 10 is placed on the first heating coil 2a based on the detected values of the input current Iin and the coil current IL. including. The determination result of the determination unit 43 is output to the control unit 7. The characteristic value of the coil current IL-the input current Iin differs between when the pan 10 is not placed on the first heating coil 2a and when it is placed.

  FIG. 4 shows a characteristic 401 of the coil current IL-input current Iin of a pan made of a certain material when the first inverter 3a is driven at a predetermined operating frequency, and the pan is placed on the first heating coil 2a. The range of the characteristics of the coil current IL−the input current Iin when it is placed and when it is not placed is shown. When the pan is placed on the first heating coil 2a and when it is not placed, the coil current IL-input current Iin when the first inverter 3a is driven at a predetermined operating frequency. The range of characteristics is different. That is, the characteristic is included in the range 402 when there is no pan, and the characteristic is included in a range other than the range 402 when there is a pan. Since the value of the characteristic 401 of the coil current IL-input current Iin shown in FIG. 4 is included in the range with the pan other than the range 402, it can be seen from this characteristic that there is no pan. Thus, by detecting the values of the input current Iin and the coil current IL as the electrical characteristics of the pan, it can be determined whether or not the pan is placed on the first heating coil 2a.

  About the induction heating cooking appliance comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  First, FIGS. 5A, 5 </ b> B, and 5 </ b> C show examples in which pans of various sizes are placed on the top plate 1. FIG. 5A shows an example in which two pans 10a and 10b having normal sizes are placed on the heating coils 2a and 2b, respectively. In this case, the first pan placement determination unit 4a and the second pan placement determination unit 4b detect the electrical characteristics of the pans 10a and 10b, respectively, and thereby the first heating coil 2a and the second pan placement determination unit 4b. It is determined that the pans 10a and 10b are placed on the heating coil 2b. On the other hand, since the pots 10 a and 10 b are not placed on the light detection unit 61, disturbance light passes through the top plate 1 and reaches the light detection unit 61. Thereby, the 3rd pan mounting discrimination | determination part 6 judges that the pan is not mounted on the top plate 1 which opposes between heating coils 2a and 2b. Therefore, the control unit 7 determines that the pans 10a and 10b placed on the heating coils 2a and 2b are separate pans and validates the input from the first input unit 8a and the second input unit 8b. The input from the third input unit 8c is invalidated, and the operation of the first inverter 3a and the operation of the second inverter 3b are controlled independently based on the control command from the operation unit 5. Thereby, the heating of the pan 10a by the first heating coil 2a and the heating of the pan 10b by the second heating coil 2b are performed independently.

FIG. 5B shows an example in which one slightly large pan 10c is placed on the heating coil 2a. In this case, the 1st pan mounting discrimination | determination part 4a judges that the pan 10c is mounted on the 1st heating coil 2a by detecting the electrical property of the pan 10c. Photodetector 6
Since the pan 10 c is placed on the 1, the ambient light does not reach the light detection unit 61 through the top plate 1. Therefore, the 3rd pan mounting discrimination | determination part 6 judges that the pan 10c is mounted between the 1st heating coil 2a and the 2nd heating coil 2b. On the other hand, the second pan placement determination unit 4b determines that the pan 10c is not placed on the second heating coil 2b. In this case, the control part 7 operates only the 1st inverter 3a, and heats the pot 10c with the 1st heating coil 2a. At this time, the control unit 7 controls the first inverter 3a based on a control command input from the operation unit 5a including the first input unit 8a.

  FIG.5 (c) has shown the example by which one large pot 10d of an oval shape is mounted ranging over heating coil 2a, 2b. In this case, the 1st pan mounting discriminating part 4a and the 2nd pan mounting discriminating part 4b detect the electrical characteristic of the pan 10d, respectively, and thereby the first heating coil 2a and the second heating coil 2b, respectively. It is determined that the pan 10d is placed on the top. Since the pan 10 d is also placed on the light detection unit 61, disturbance light does not reach the light detection unit 61 through the top plate 1. Therefore, the 3rd pan mounting discrimination | determination part 6 judges that the pan 10d is mounted between the 1st heating coil 2a and the 2nd heating coil 2b. The control unit 7 determines that the same pan is placed on the first heating coil 2a and the second heating coil 2b, and both the first heating coil 2a and the second heating coil 2b. Thus, it is possible to link the operation of the first inverter 3a and the operation of the second inverter 3b so as to heat one pan 10d. Here, when there is an input from the third input unit 8c on the operation unit 5a and / or the operation unit 5b, the control unit 7 is based on a control command input from the third input unit 8. Both the first inverter 3a and the second inverter 3b are controlled in cooperation. At this time, input from the first input unit 8a and the second input unit 8c is prohibited when the control command from the input unit 8c becomes valid.

  In addition, when the input from the 1st input part 8a and the 2nd input part 8c is selected, the input from the 3rd input part 8c is prohibited, and the control part 7 follows the instruction | command from the operation part 5 The first inverter 3a and the second inverter 3b are controlled independently.

  In the present embodiment, it is possible to heat one pan using both the first heating coil 2a and the second heating coil 2b. However, about the 3rd heating coil 2c, the operation | movement which heats one pan in cooperation with the other heating coils 2a or 2b is not assumed. Therefore, when the user places a pan on the third heating coil 2c and inputs a control command to start heating via the operation unit 5c for the third heating coil 2c, the control unit 7 3 inverter 3c is driven to operate only the third heating coil 2c. Since such control is normal control conventionally performed, detailed description is omitted. Hereinafter, in the present embodiment, operations related to heating control using the first heating coil 2a and the second heating coil 2b will be described.

FIG. 6 shows a schematic inverter drive control in the induction heating cooker of the present embodiment. In the present embodiment, the user selects whether the first heating coil 2a and the second heating coil 2b are operated in cooperation by the first to third input units 8a, 8b, and 8c of the operation unit 5. When the cooperative operation is selected (Yes in S501), the first, second, and third pan placement determining units 4a, 4b, and 6 each determine whether or not the pan is placed (S502). When all of the first, second, and third pan placement discriminating units 4a, 4b, and 6 discriminate that the pan is placed (Yes in S502), the first inverter 3a and the second inverter Control is performed so that the operations of 3b are linked (S503, see FIG. 5C). When at least one of the first, second, and third pan placement discriminating units 4a, 4b, and 6 does not discriminate that the pan is placed (No in S502), the control unit 7 cooperates. Informing that the operation is impossible, the first inverter 3a and the second inverter 3b wait for a command in a state where they operate independently, that is, in a state where they operate independently (S504, FIGS. 5A and 5B). reference). At this time, when the user selects an operation using either the first input unit 8a or the second input unit 8b, the control unit 7 determines that the first inverter 3a and the second inverter 3b are independent, That is, control is performed so as to operate independently.

  FIG. 7 shows an operation flow in which FIG. 6 is further detailed. FIG. 7 shows an example of an operation when the user selects a cooperative operation using the third input unit 8c. The control unit 7 determines whether or not an instruction to start heating by the cooperative operation is input from the operation unit 5a (S601). When the start of heating is instructed (Yes in S601), the first pan placement discriminating unit 4a detects whether the pan is placed on the first heating coil 2a by detecting the electrical characteristics of the pan. It is determined whether or not (S602). At this time, the control unit 7 drives the first inverter 3a to energize the first heating coil 2a so that the first pan placement determination unit 4a can detect the electrical characteristics of the pan. is doing.

  Even if the start of heating is instructed, if the pan is not placed on the first heating coil 2a (No in S602), the control unit 7 determines that the cooperative operation cannot be performed and does not perform heating. At this time, the control part 7 stops the 1st inverter 3a which was driving in order to detect the electrical property of a pan.

  When the pan is placed on the first heating coil 2a (Yes in S602), the third pan placement discriminating unit 6 uses the first heating coil 2a and the second heating coil 2 based on the detection of ambient light. It is determined whether or not a pan is placed between the heating coil 2b (S603). When the pan is placed between the first heating coil 2a and the second heating coil 2b (Yes in S603), the second pan placement determination unit 4b detects the electrical characteristics of the pan. Thus, it is determined whether or not the pan is placed on the second heating coil 2b (S604). At this time, the control unit 7 drives the second inverter 3b to energize the second heating coil 2b so that the second pan placement determination unit 4b can detect the electrical characteristics of the pan. is doing. When the pan is also placed on the second heating coil 2b (Yes in S604), the control unit 7 is on the top plate 1 facing both the first heating coil 2a and the second heating coil 2b. It is determined that one large pan is placed on the first inverter 3a, and both the first inverter 3a and the second inverter 3b are operated in cooperation (see FIG. 5C). Thereby, one large pan is heated by both the 1st heating coil 2a and the 2nd heating coil 2b (S605).

  Even if the pan is placed on the first heating coil 2a, if the pan is not placed between the first heating coil 2a and the second heating coil 2b (Yes in S602 and No in S603, Since the control unit 7 cannot perform a cooperative operation, heating is stopped and an independent control input reception state is set (S606). Even if a pan is placed on the first heating coil 2a and between the first heating coil 2a and the second heating coil 2b, the pan is placed on the second heating coil 2b. If not (Yes in S602, Yes in S603, and No in S604, see FIG. 5 (b)), the control unit 7 cannot operate in cooperation, so heating is stopped and an independent control input acceptance state (first input) The command from the means 8a or the second input means 8b is set to standby) (S606). At this time, the control unit 7 stops the second inverter 3b that has been driven to detect the electrical characteristics of the pan.

  The control unit 7 determines whether the operation unit 5 is operated and an instruction to end heating is input (S607). When an instruction to end heating is input (Yes in S607), the control unit 7 ends the heating.

The cooperative operation of the first inverter 3a and the second inverter 3b when one pan is heated by both the first heating coil 2a and the second heating coil 2b will be described with reference to FIG. Fig.8 (a) has shown the thermal power setting (W) set by the user via the operation part 5a or the operation part 5b. 8B and 8C show the heating power (W) of the first heating coil 2a and the heating of the second heating coil 2b when the first inverter 3a and the second inverter 3b are operated in cooperation. Electric power (W) is shown. The control unit 7 is configured so that the heating power amount of the first heating coil 2a and the second heating coil 2b corresponds to the heating power setting set by the user, and the first heating coil 2a and the second heating coil The first inverter 3a and the second inverter 3b are cooperatively operated so that the power ratio of 2b is always substantially constant (A ′ / A≈B ′ / B).

  FIG. 9 shows the heating power amounts of the first heating coil 2a and the second heating coil 2b when the first inverter 3a and the second inverter 3b are operated independently and when they are operated in a coordinated manner, respectively. During the single operation of the first inverter 3a and the second inverter 3b, the heating power amount of the first heating coil 2a and the second heating coil 2b is individually set to a value corresponding to the thermal power setting. For example, the heating power amount of the first heating coil 2a and the second heating coil 2b when the thermal power setting is “1” is 150 W. When the thermal power setting is “8”, the heating power amount of the first heating coil 2 a is 3000 W, and the heating power amount of the second heating coil 2 b is 1400 W. Thus, in the case of a single operation, the electric energy of the first heating coil 2a and the second heating coil 2b is set independently.

  On the other hand, during the cooperative operation of the first inverter 3a and the second inverter 3b, the amount of heating power of the first heating coil 2a and the second heating coil 2b is the power ratio (second heating coil 2b / The first heating coil 2a) is set according to the thermal power setting so that the first heating coil 2a is always substantially constant (here, “about 1/2”). For example, when the heating power setting is “1”, the heating power amount of the first heating coil 2 a is 100 W, and the heating power amount of the second heating coil 2 b is 50 W. When the thermal power setting is “8”, the heating power amount of the first heating coil 2a is 2000 W, and the heating power amount of the second heating coil 2b is 1000 W. Further, the total amount of electric power of the first heating coil 2a and the second heating coil 2b during the cooperative operation of the first inverter 3a and the second inverter 3b is the same as that when the first inverter 3a is operated alone. It is set to be equal to the heating power amount of one heating coil 2a.

  In addition to the first input unit 8a that causes the operation unit 5 to operate at least the first heating coil 2a alone and the second input unit 8b that operates the second heating coil 2b alone, the first heating coil 2a A third input unit 8c for operating the second heating coil 2b at the same time is newly provided, and by operating the first heating coil 2a and the second heating coil 2b simultaneously, it is as if a large pan with one heating coil. Can be operated as if heated. Therefore, for example, when it is determined that one large pan is placed on the top plate facing the plurality of heating coils, the plurality of heating coils can be driven in cooperation. As a result, the heating distribution is not biased, and one large pot can be heated without impairing the cooking performance.

Moreover, the first heating coil 2a and the second heating coil are determined only by the first pan mounting determination unit 4a and the second pan mounting determination unit 4b determining that the pan 10 is mounted. It is discriminated whether different pans are placed on the top plate 1 facing 2b (FIG. 5 (a)) or whether a large pan is placed (FIG. 5 (c)). I can't. However, according to the induction heating cooker of the present embodiment, the third pan placement determining unit 6 is provided below the top plate 1 facing between the first heating coil 2a and the second heating coil 2b. It is determined whether or not a pan is placed on the top plate 1 between the first heating coil 2a and the second heating coil 2b. Therefore, in addition to the discrimination results of the first pan placement discrimination unit 4a and the second pan placement discrimination unit 4b, the discrimination results of the third pan placement discrimination unit 6 can be used. Thereby, when all of the 1st pan mounting discrimination | determination part 4a, the 2nd pan mounting discrimination | determination part 4b, and the 3rd pan mounting discrimination | determination part 6 discriminate | determined that the pan is mounted, It can be determined that the pan placed on the first heating coil 2a and the pan placed on the second heating coil 2b are the same. Based on the determination result, the control unit 7 enables the operations of the first inverter 3a and the second inverter 3b to cooperate.

  In the present embodiment, the power amount of each of the first heating coil 2a and the second heating coil 2b is determined so as to be substantially constant during the cooperative operation. When the setting is small, it is difficult to keep the amount of power low. Therefore, when the thermal power setting is small, the amount of power per predetermined time may be lowered by reducing the power supply time to the heating coil. FIG. 10 shows an example of reducing the power supply time. FIG. 10A shows the thermal power setting set by the user, FIG. 10B shows the heating power of the first heating coil 2a, and FIG. 10C shows the heating power of the second heating coil 2b. Is shown. 10A to 10C illustrate cases where it is difficult to suppress the amount of power to less than 100 W. When the thermal power setting is “2” (time t1 to t2), the amount of power of the second heating coil 2b is 100 W, so the second inverter 3b continues to supply 100 W of power to the second heating coil. On the other hand, when the thermal power setting is changed to “1” (time t2), the power amount of the second heating coil 2b must be reduced to 50 W (see FIG. 9). Therefore, the second inverter 3b sets the time for supplying power to the second heating coil 2b to 50% (time t2 to t3) so that the total amount of power per predetermined time is 50W. That is, a time for supplying power to the heating coil 2b and a time for not supplying power are provided. Thereby, the apparent electric energy of time t2-t3 becomes 50W. As described above, when it is difficult to suppress to the predetermined power amount (amplitude), the apparent power amount may be controlled to be the predetermined amount by reducing the power supply time (width).

  In the present embodiment, the power ratio of the heating power of the first heating coil 2a and the second heating coil 2b during the cooperative operation is always substantially constant, but it is not always necessary to be constant. The power ratio may be made variable according to the thermal power setting. For example, the power ratio may be increased as the thermal power setting is increased.

  Note that during the cooperative operation, the operation timings of the first inverter 3a and the second inverter 3b may be matched without setting the power ratio according to the thermal power setting. For example, the controller 7 first starts and stops heating by the first heating coil 2a and the second heating coil 2b at the same time according to the timing when the heating on / off instruction is given. The operation timings of the inverter 3a and the second inverter 3b may be matched. In addition, the timing of changing the electric energy of the first heating coil 2a and the second heating coil 2b may be adjusted in accordance with the timing of changing the heating power setting.

  In the present embodiment, only the third pan placement discriminating unit 6 includes the light detection unit 61, but the first pan placement discriminating unit 4a and the second pan placement discriminating unit 4b are further provided. May include a light detection unit. That is, also about the 1st pan mounting determination part 4a and the 2nd pan mounting determination part 4b, a pan is mounted on the 1st heating coil 2a and the 2nd heating coil 2b by the detection of disturbance light. It may be determined whether or not each of them. In this case, it is preferable to provide the light detection part of the 1st pan mounting determination part 4a inside the outer edge of the 1st heating coil 2a. Moreover, it is preferable to provide the light detection part of the 2nd pan mounting determination part 4b inside the outer edge of the 2nd heating coil 2b.

  When the operating frequency of the first inverter 3a and the operating frequency of the second inverter 3b are different, the difference becomes an audible sound and can be heard by the user. Therefore, when operating the 1st inverter 3a and the 2nd inverter 3b in cooperation, the control part 7 controls so that the operating frequency of the 1st inverter 3a and the 2nd inverter 3b may become the same. Is preferred.

(Embodiment 2)
In Embodiment 2 of the present invention, another method for determining whether the pans placed on the top plate 1 facing the first heating coil 2a and the second heating coil 2b are the same will be described. Specifically, in the present embodiment, in addition to the results of determining the pan placement of the first to third pan placement discriminating units 4a, 4b, 6, the material of the pan is further discriminated, thereby It is determined whether or not the pans placed on the top plate 1 facing the heating coil 2a and the second heating coil 2b are the same. In the present embodiment, the structure of the induction heating cooker is the same as that of FIG.

  In the present embodiment, the first pan placement discriminating unit 4a and the second pan placement discriminating unit 4b detect the electrical characteristics of the pans placed so as to face the heating coils 2a and 2b, respectively. To the control unit 7. If the electrical characteristics detected from the 1st pan mounting discrimination | determination part 4a and the 2nd pan mounting discrimination | determination part 4b are the same, the control part 7 will be on the 1st heating coil 2a and the 2nd heating coil. It is judged that the pan placed on 2b is the same pan.

Fig. 11 (a) and (b) show the electrical characteristics of the pan, respectively. Specifically, FIG. 11A shows characteristics of the operating frequency of the inverter and the coil current flowing through the heating coil. As shown to Fig.11 (a), the characteristic of an operating frequency-coil current changes with the materials A and B of a pan. Specifically, since the resonance frequency determined by the heating coil and the resonance capacitor of the inverter differs depending on the material of the pan, the current value of the heating coil when the control unit 7 drives the inverter at a predetermined operating frequency is It depends on the material. Therefore, for example, the material of the pan can be specified by comparing the coil current values I _LA and I _LB at a predetermined operating frequency with the reference value I _LREF .

FIG. 11B shows the characteristics of the input current of the inverter and the coil current flowing through the heating coil. As shown in FIG. 11 (b), the characteristics of the input current and the coil current differ depending on the materials A and B of the pan. Specifically, the characteristics of the input current and the coil current differ depending on the difference in the high frequency resistance of the pan. Therefore, for example, the material of the pan can be specified by comparing the input current-coil current with the reference value _IREF .

In this way, the electrical characteristics (operating frequency-coil current characteristics and / or input current-coil current) of the pan placed on the first heating coil 2a and the second heating coil 2b are as follows. It depends on the material. Therefore, the control unit 7 more specifically compares the electrical characteristics of the pan detected by the first pan mounting determination unit 4a and the second pan mounting determination unit 4b. Comparing the material of the pan identified by comparing the electrical characteristics of the pan detected by the pan placement determination unit 4a and the second pan placement determination unit 4b with the reference value I _LREF and / or the reference value I _REF Thus, it can be determined whether or not the material of the pan placed on the first heating coil 2a and the second heating coil 2b is the same.

  In FIG. 12, operation | movement of the induction heating cooking appliance of this Embodiment is shown. FIG. 12 shows a case where the third input means 8c in the operation unit 5 is operated and an instruction to start heating is input as in FIG. In FIG. 12, the order of the determination step S1103 by the second pan placement determination unit 4b and the determination step S1105 by the third pan placement determination unit 6 is reversed to steps S603 and S604 in FIG. Step S1104 for discriminating the material of the pan is newly added between steps S1103 and S1105. For the other steps, FIG. 12 is the same as FIG. Explanation of the same steps is omitted.

  In the induction heating cooker, after the first pan placement discriminating unit 4a and the second pan placement discriminating unit 4b discriminate that the pan is placed (Yes in S1102 and Yes in S1103), It is determined whether or not the material of the pan placed on the first heating coil 2a and the second heating coil 2b is the same (S1104). Specifically, the control unit 7 determines whether the pan on the first heating coil 2a is based on the electrical characteristics detected from the first pan placement determination unit 4a and the second pan placement determination unit 4b. It is determined whether the material of the pan on the second heating coil 2b is the same.

  If the material of the pan on the 1st heating coil 2a and the pan on the 2nd heating coil 2b are the same (Yes in S1104), the 3rd pan mounting discrimination | determination part 6 will be the 1st heating coil 2a. It is determined whether or not a pan is placed on the top plate 1 facing the second heating coil 2b (S1105). When the material of the pan on the first heating coil 2a and the material of the pan on the second heating coil 2b are the same and the third pan placement determining unit 6 determines that the pan is placed (Yes in S1104) In S1105, the control unit 7 determines that the pans placed on the first heating coil 2a and the second heating coil 2b are the same pan, and the first inverter 3a and the second The inverter 3b is operated in cooperation. Thereby, one pan is heated with both the 1st heating coil 2a and the 2nd heating coil 2b (S1106).

  If the material of the pan on the first heating coil 2a and the material on the second heating coil 2b are not the same (No in S1104), and even if the material of the pan is the same, the third pan placement determining unit If 6 determines that the pan is not placed (No in S1105), the controller 7 determines that the pan placed on the first heating coil 2a and the second heating coil 2b is another pan. It is judged that. At this time, since the control unit 7 cannot perform a cooperative operation, the heating is stopped and an independent control input acceptance state is set (waiting for a command from the first input unit 8a or the second input unit 8b) (S1107). Here, heating can be performed by instructing the start of heating with the first input means 8a or the second input means 8b in the operation unit 5.

  Thus, by adding the step (S1104) of judging whether the material of the pan is the same using the electrical characteristics, the first heating coil 2a and the second heating coil 2a are compared with the first embodiment. It is possible to more accurately determine whether the pan on the heating coil 2b is one pan or another pan.

(Embodiment 3)
In Embodiment 3 of the present invention, another method for determining pan placement by the third pan placement discriminating unit will be described. In the present embodiment, the third pan placement discriminating unit is on the top plate 1 facing between the first heating coil 2a and the second heating coil 2b on the basis of the detected increase in temperature. It is determined whether or not the pan is placed. In FIG. 13, the structure of the induction heating cooking appliance of this Embodiment is shown. In the induction heating cooker according to the present embodiment, the third pan placement discriminating unit 6 a has a temperature detection unit 62 that detects the temperature of the pan 10. The temperature detector 62 is, for example, an infrared sensor that detects infrared rays emitted from the pan 10 or a thermistor that detects the temperature of the pan 10 via the top plate 1. Similar to the light detection unit 61 of the first embodiment, the temperature detection unit 62 is provided below the top plate 1 and in a region 600 between the first heating coil 2a and the second heating coil 2b. (See FIG. 2). Based on the temperature detected by the temperature detection unit 62, the third pan placement determination unit 6a has the pan 10 placed on the top plate 1 facing the first heating coil 2a and the second heating coil 2b. Determine whether or not. In the induction heating cooker of the present embodiment, the configuration other than that the third pan placement determination unit 6a has a temperature detection unit 62 instead of the light detection unit 61 is the configuration of FIG. 1 of the first embodiment. Is the same.

In FIG. 14, the graph of the temperature rise amount of the pan detected by the temperature detection part 62 is shown. When the pan is not placed between the first heating coil 2a and the second heating coil 2b, for example, the line 140 in FIG. 14 is separately provided on the first heating coil 2a and the second heating coil 2b. This shows a case where the pan is placed (see FIG. 5A). In this case, since no pan is placed on the temperature detection unit 62, the detected temperature rise ΔA detected by the temperature detection unit 62 at the predetermined time T1 is small. On the other hand, the line 141 in FIG. 14 shows a case where a pan is placed between the first heating coil 2a and the second heating coil 2b (see FIGS. 5B and 5C). . In this case, since the pan is placed on the temperature detection unit 62, the temperature increase ΔB detected by the temperature detection unit 62 within the predetermined time T1 is larger than ΔA. Thus, the amount of temperature rise detected by the temperature detection unit 62 within the predetermined time T1 varies depending on whether the pan is placed between the first heating coil 2a and the second heating coil 2b. Therefore, it is possible to determine whether or not the pan is placed between the first heating coil 2a and the second heating coil 2b by comparing the temperature increase amount within the predetermined time T1 with the reference value.

  In the present embodiment, since the temperature detection unit 62 detects the temperature and determines the placement of the pan, the control unit 7 inputs the heating start instruction when the heating start instruction is input. The inverter corresponding to the operated unit 5 is driven to supply a high frequency current to the heating coil. For example, when the start of heating is instructed via the operation unit 5a for the first heating coil 2a, the control unit 7 controls the first inverter 3a to supply a high-frequency current to the heating coil 2a. Thereby, it is possible to determine the pan placement based on the temperature detection of the third pan placement determination unit 6a. After determining the pan placement by the third pan placement discriminating unit 6a, for example, if it is discriminated that the pan is not placed on the first heating coil 2a, the control unit 7 detects the temperature. The operation of the first inverter 3a that has been driven is stopped.

  The determination of the pan placement and the operation control of the inverter after the pan placement discrimination when the third pan placement discriminating unit 6a of the present embodiment is used are the same as those in the first embodiment or the second embodiment. is there. According to the induction heating cooker using the third pan placement discriminating unit 6a of the present embodiment, the same effect as the induction heating cooker of the first embodiment or the second embodiment is obtained.

  In the present embodiment, only the third pan placement discriminating unit 6a is provided with the temperature detection unit 62, but the first pan placement discriminating unit 4a and the second pan placement discriminating unit 4b are further provided. May include a temperature detector 62. That is, also about the 1st pan mounting discriminating part 4a and the 2nd pan mounting discriminating part 4b, a pan is mounted on the 1st heating coil 2a and the 2nd heating coil 2b by the amount of temperature rise to detect. It may be determined whether each has been performed. In this case, it is preferable to provide the temperature detection part of the 1st pan mounting discrimination | determination part 4a below the top plate 1 and inside the outer edge of the 1st heating coil 2a. Moreover, it is preferable to provide the temperature detection part of the 2nd pan mounting discrimination | determination part 4b below the top plate 1 and inside the outer edge of the 2nd heating coil 2b.

  In Embodiments 1 to 3, the configuration and operation of the induction heating cooker can be arbitrarily combined. For example, the first pan placement determination unit 4a and the second pan placement determination unit 4b have the configuration shown in FIG. 3 and the light detection unit 61 (corresponding to a modification of the first embodiment), and the third The induction heating cooker in the case where the pan placement determination unit 6a has the temperature detection unit 62 (corresponding to the third embodiment) may perform the operation shown in FIG. 12 (corresponding to the second embodiment).

  In the first to third embodiments, the place where the third pan placement determining units 6 and 6a are disposed is not limited to the present embodiment. For example, you may provide the 3rd pan mounting determination part 6 or 6a between the 2nd heating coil 2b and the 3rd heating coil 2c. In this case, it is determined whether a pan is placed on the top plate 1 between the second heating coil 2b and the third heating coil 2c, and the second heating coil 2b and the third heating coil 2c are determined. When the pan is placed on the top plate 1 between the second inverter 3b and the third inverter 3c, the pan may be driven in cooperation. Thereby, one pan placed on the top plate 1 can be heated so as to straddle the second heating coil 2b and the third heating coil 2c. Similarly, between the first heating coil 2a and the third heating coil 2c, a third pan placement determining unit 6 or 6a is provided, and the first heating coil 2a and the third heating coil 2c are provided. When it is determined that one pan is placed on the opposing top plate 1, the first inverter 3a and the third inverter 3c may be linked to operate.

Moreover, in Embodiment 1 to Embodiment 3, the number of the 3rd pan mounting determination parts 6 and 6a is not limited to the said embodiment. In other words, a plurality of third pan placement determining units 6 or 6a may be provided. For example, the third pan placement discriminating unit 6 or 6a described above is provided between the first heating coil 2a and the second heating coil 2b, and between the second heating coil 2b and the third heating coil 2c. You may provide in both.

  Further, in the first to third embodiments, the number of inverters to be operated in cooperation is not limited to the above embodiment. For example, when a plurality of third pan placement discriminating units 6 or 6a are provided, three or more inverters are operated in cooperation so that one pan can be heated using three or more heating coils. Also good.

  In the present invention, since it is possible to determine whether the same pan is placed on the top plate facing the plurality of heating coils or different pans are placed, a large pan such as an oval shape is used. It is useful for induction heating cookers that heat.

The block diagram which shows the structure of the induction heating cooking appliance in Embodiment 1 of this invention. The top view of the top plate of the induction heating cooking appliance in Embodiment 1 of this invention The figure which shows the internal structure of the 1st pan mounting discrimination | determination part of the induction heating cooking appliance in Embodiment 1 of this invention. Input current vs. coil current characteristics (A) The figure which shows the example in which the pan of normal size was mounted (b) The figure which shows the example in which the somewhat large pot was mounted (c) The figure which shows the example in which the oval large pot was mounted The flowchart which shows the operation | movement of the outline of the induction heating cooking appliance in Embodiment 1 of this invention. The flowchart which shows the detailed operation | movement of the induction heating cooking appliance in Embodiment 1 of this invention. It is a figure in the case of making operation | movement of a 1st inverter and a 2nd inverter cooperate, Comprising: (a) is a figure which shows a thermal power setting, (b) is a figure which shows the heating power of a 1st heating coil, (c) Is a diagram showing the heating power of the second heating coil The figure which shows the value of the heating electric power of a 1st heating coil and a 2nd heating coil It is a figure which shows the example of the power ratio constant at the time of cooperation operation | movement, Comprising: (a) is a figure which shows thermal power setting, (b) is a figure which shows the heating power of a 1st heating coil, (c) is 2nd heating Diagram showing coil heating power (A) Operating frequency and coil current characteristic diagram (b) Input current and coil current characteristic diagram The flowchart which shows operation | movement of the induction heating cooking appliance in Embodiment 2 of this invention. The block diagram which shows the structure of the induction heating cooking appliance in Embodiment 3 of this invention. Figure showing the temperature rise of the pan

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Top plate 2a 1st heating coil 2b 2nd heating coil 2c 3rd heating coil 3a 1st inverter 3b 2nd inverter 3c 3rd inverter 4a 1st pan mounting discrimination | determination part 4b 2nd pan Placement discriminating unit 4c 4th pan placing discriminating unit 5 Operation unit 6, 6a 3rd pan placing discriminating unit 7 Control unit 8a 1st input unit 8b 2nd input unit 8c 3rd input unit 10 Pan 41 Input Current Detection Unit 42 Coil Current Detection Unit 43 Discrimination Unit 61 Light Detection Unit 62 Temperature Detection Unit

Claims (14)

A top plate for placing a cooking vessel, first and second heating coils disposed below the top plate and having different circular centers for heating the cooking vessel, and the first and second heatings A control unit that performs heating control of the coil, a first inverter that is controlled by the control unit to supply power to the first heating coil, and that is controlled by the control unit to supply power to the second heating coil. A second inverter to be supplied; and an operation unit for instructing an operation state to the control unit, wherein the operation unit operates at least the first heating coil alone and the first input unit and the second heating coil. An induction heating cooker, comprising: a second input unit that operates independently, and a third input unit that operates the first heating coil and the second heating coil simultaneously. First and second pan placement discriminating units for discriminating whether or not a cooking container is placed on a top plate facing each of the first and second heating coils; and the first and second A third pan placement discriminating unit that discriminates whether or not the cooking container is placed on the top plate facing between the heating coils, and the control unit includes the first pan placement discriminating unit and When all of the second pan placement discriminating unit and the third pan placement discriminating unit discriminate that the cooking container is placed, accepting commands from the first to third input units The induction heating cooker according to claim 1, which makes possible. The induction heating cooking appliance of Claim 2 which prohibits the reception from the said 1st and 2nd input part, when the instruction | indication from the said 3rd input part is received. The induction heating cooking appliance of Claim 2 which prohibits the acceptance from the said 3rd input part, when the instruction | command from the said 1st or 2nd input part is received. The controller links the operation of the first inverter and the operation of the second inverter when the one cooking container is heated by both the first heating coil and the second heating coil. The induction heating cooker according to claim 2. The controller may control the first heating coil and the second heating coil so that at least one timing among the start of heating, the stop of heating, and the change of heating power coincide with each other. The induction heating cooker according to claim 5, wherein the operations of the inverter and the second inverter are linked. The first inverter and the second inverter supply electric power so that a ratio of the electric energy of the first heating coil and the electric energy of the second heating coil is constant. Induction heating cooker. The third pan placement discriminating unit is a disturbance incident from the top plate at a position below the top plate and opposed between the first heating coil and the second heating coil. A light detection unit that detects light, and when the light detection unit detects disturbance light, a cooking container is placed on the top plate facing between the first heating coil and the second heating coil; When it is determined that the light detection unit has not detected disturbance light, a cooking container is placed on the top plate facing between the first heating coil and the second heating coil. The induction heating cooker according to claim 2, which is determined to be placed. The temperature at which the third pan placement determining unit detects the temperature of the cooking container at a position below the top plate and between the first heating coil and the second heating coil. A cooking container on a top plate that has a detection unit and faces between the first heating coil and the second heating coil when the temperature detection unit detects a predetermined amount of temperature rise within a predetermined time period; The induction heating cooker according to claim 2, wherein it is determined that is placed. The second pan placement discriminating unit is a light detection unit that detects disturbance light incident from the top plate at a position below the top plate and facing the inner side of the outer edge of the second heating coil. And when the light detection unit detects disturbance light, it is determined that a cooking container is not placed on the top plate facing the second heating coil, and the light detection unit detects disturbance light. The induction heating cooker according to claim 2, wherein when it is not detected, it is determined that a cooking container is placed on the top plate facing the second heating coil. The second pan placement determination unit has a temperature detection unit that detects the temperature of the cooking container at a position below the top plate and facing the inner side of the outer edge of the second heating coil, 3. The induction according to claim 2, wherein when the temperature detection unit detects a temperature increase of a predetermined amount within a predetermined time, it is determined that a cooking container is placed on the top plate facing the second heating coil. Cooking cooker. The first pan placement determination unit detects electrical characteristics of a cooking container placed on a top plate facing the first heating coil, and the second pan placement determination unit An electrical characteristic of the cooking container placed on the top plate facing the second heating coil is detected, and the control unit is configured to detect the first pan placement determination unit and the second pan placement determination unit. And all of the third pan placement discriminating units discriminate that the cooking container is placed, and the electricity detected from the first pan placement discriminating unit and the second pan placement discriminating unit 3. The induction heating according to claim 2, wherein it is determined that the same cooking container is placed on a top plate facing the first heating coil and the second heating coil when the target characteristics are the same. Cooking device. The induction heating cooker according to claim 2, wherein the control unit controls the operating frequency of the first inverter and the second inverter to be the same. When the control unit determines that all of the first pot mounting determination unit, the second pot mounting determination unit, and the third pot mounting determination unit are mounted with a cooking container. The induction heating cooker of Claim 2 which displays that the instruction | command from the said 3rd input part was attained.