JP5355197B2 - Induction heating cooker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an induction heating cooker capable of reducing an uneven cooking and heating food with higher heating power, even when heating a cookware with the larger diameter than that of a heating coil equipped at the induction heating cooker. <P>SOLUTION: The induction heating cooker has a top plate 2, a plurality of heating coils 37, 38 mounted under the top plate 2, a plurality of inverter circuits 19, 20 to supply a high-frequency power to the heating coil, an input-power detector 12 to detect the input power of the inverter circuit, an input setter 5 capable of setting a heating output and a heating-operation mode, and a controller 44 to display an operating condition in a display unit 6 on receipt of the input from the input setter 5, and to actuate and control the inverter circuits 19, 20. Further, the cooker has, in the heating-operation mode capable of setting in the input setter 5, a heating-output integrating mode to integrally control the heating output to the plurality of heating coils 37, 38, and an individually heating-output setting mode to individually control the heating output to the plurality of heating coils 37, 38. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to an induction heating cooker having a plurality of heating coils.

  In a conventional induction heating cooker, “a pan of a size corresponding to the diameter of the heating coil on the top plate and at least one of the plurality of heating coils having a diameter different from the diameter of the other heating coils. There was a device provided with a position display section (for example, see Patent Document 1). In the induction heating cooker described in Patent Document 1, by providing a heating coil having a diameter different from the diameters of the other heating coils, heating can be efficiently performed even when a small pan is used.

JP 2004-186002 (3rd page, FIG. 1)

  However, when using a pot or frying pan having a diameter larger than that of the heating coil provided in the induction heating cooker, the heating power for heating the pot or frying pan may be insufficient. Moreover, since the magnetic lines of force from the heating coil are linked only to a part of the pan bottom, large heating unevenness may occur.

  This invention is made in order to solve the above problems, and suppresses uneven heating even when a cooking container having a diameter larger than the diameter of the heating coil provided in the induction heating cooker is heated. In addition, the present invention provides an induction heating cooker that enables heating with higher heating power.

An induction heating cooker according to the present invention includes a top plate on which an object to be heated is placed, two heating coils arranged below the top plate and arranged side by side with different center positions, and the heating coil Two inverter circuits for supplying high-frequency current to each of them, power detection means for detecting input power or output power of the inverter circuit, input setting means for setting a heating output and a heating operation mode, and the input setting means receiving enter from and control means for driving and controlling the inverter circuit, wherein the heating operation mode can be set in the input setting unit heating power integral for controlling integrally the heating power to said two heating coils possess a mode, a heating output individual mode for individually controlling the heating power to said two heating coils, one of said heating coil, winding a coil wire in a substantially elliptical shape The other of the heating coils is formed by winding a coil conductor in a substantially circular shape, and the pitch P0 of the coil conductor of the heating coil wound in the substantially circular shape is substantially elliptical. It is wider than the pitch P1 of the coil conductor in the short diameter direction of the heating coil wound around the coil and is narrower than the pitch P2 of the coil conductor in the long diameter direction .

  According to the present invention, when the integrated heating mode is set, the plurality of inverter circuits are driven and controlled, and high-frequency currents are supplied to the plurality of heating coils. For this reason, one pot can be heated with a plurality of heating coils. Therefore, an induction eddy current is generated in a pan bottom having a larger area to suppress uneven heating of a large-diameter pan, and heating with a higher heating power is possible.

1 is an external view of an induction heating cooker according to Embodiment 1. FIG. It is a circuit block diagram of the induction heating cooking appliance which concerns on Embodiment 1. FIG. It is a figure which shows the shape and arrangement | positioning of the 1st heating coil of the induction heating cooking appliance which concerns on Embodiment 1, and a 2nd heating coil. It is a side surface cross-section schematic diagram which shows the positional relationship of the 1st heating coil of the induction heating cooking appliance which concerns on Embodiment 1, and a 2nd heating coil. It is a figure which shows the input setting means and display part of the induction heating cooking appliance which concern on Embodiment 1. FIG. It is a flowchart which shows the heating mode switching process of the induction heating cooking appliance which concerns on Embodiment 1. FIG. It is a flowchart which shows the individual heating control process of the induction heating cooking appliance which concerns on Embodiment 1. FIG. It is a flowchart which shows the integral heating control process of the induction heating cooking appliance which concerns on Embodiment 1. FIG. It is a figure which shows the other shape and arrangement | positioning of the 1st heating coil of the induction heating cooking appliance which concerns on Embodiment 1, and a 2nd heating coil. It is a flowchart which shows the integral heating control process of the induction heating cooking appliance which concerns on Embodiment 2. FIG. It is an example of the heat display of the induction heating cooking appliance which concerns on Embodiment 3. It is a side surface cross-section schematic diagram of the principal part of the induction heating cooking appliance which concerns on Embodiment 4. It is a top view of the top plate in the individual heating mode of the induction heating cooking appliance which concerns on Embodiment 4. It is a top view of the top plate in the integral heating mode of the induction heating cooking appliance which concerns on Embodiment 4.

Embodiment 1 FIG.
In the first embodiment, an induction heating cooker having two heating ports, a first heating port and a second heating port, will be described as an example.
FIG. 1 is a diagram showing an induction heating cooker according to Embodiment 1 of the present invention, FIG. 1 (A) is a perspective view showing an appearance, and FIG. 1 (B) is a top view. In FIG. 1, the top plate 2 which mounts the cooking container which is a to-be-heated object is installed in the upper surface of the main body 1 of the induction heating cooking appliance.

  On the top 2, a first placement position display unit 3 and a second placement position display unit 4 are displayed as positions where the cooking containers are to be placed. The first placement position display unit 3 is displayed in a substantially circular shape at a position on the near side of the top plate 2. The second placement position display unit 4 is displayed in a horizontally long elliptical shape at a position on the back side of the top plate 2.

  Inside the main body 1 located below the first placement position display section 3 and the second placement position display section 4, heating coils having shapes similar to the shapes of the respective placement position display sections (see FIG. 1). (Not shown) is provided, and a high frequency power supply circuit and a control circuit (not shown in FIG. 1) for supplying a high frequency current to the heating coil are also provided inside the main body 1.

  Further, an input setting unit 5 for setting the heating power of each heating port is provided on the side surface on the front side of the main body 1. The input setting unit 5 includes a first heating power setting unit 5a that performs heating on / off of the first heating port and a heating power setting, a second heating power setting unit 5b that performs heating switching of the second heating port and a heating power setting, and an individual heating mode. And a change-over switch 5c for switching between the integrated heating mode.

Here, the induction heating cooker according to the first embodiment can operate in two heating modes, that is, the individual heating mode and the integral heating mode.
The individual heating mode is a mode in which the first heating port and the second heating port are individually controlled, and a pan is placed on the first heating port and the second heating port, respectively, and heating is possible. In addition, the integrated heating mode is a mode in which one pan placed so as to straddle the first heating port and the second heating port can be heated using the first heating port and the second heating port, The first heating port and the second heating port are controlled as a unit. In the first embodiment, the heating output individual mode of the present invention corresponds to the individual heating mode, and the heating output integrated mode corresponds to the integrated heating mode.

  Moreover, the display part 6 which shows the heating output state of a 1st heating port and a 2nd heating port is provided. The display unit 6 displays a first heating power display unit 6a indicating the heating power of the first heating port, a second heating power display unit 6b indicating the heating power of the second heating port, and a mode for displaying the distinction between the individual heating mode and the integrated heating mode. A display lamp 6c is provided. The 1st thermal power display part 6a and the 2nd thermal power display part 6b are each comprised by light emitting elements, such as LED, and according to the setting thermal power of a 1st heating port and a 2nd heating port during operation in individual heating mode. A number of light emitting elements are lit and displayed. During operation in the integrated heating mode, the mode display lamp 6c is turned on and the set thermal power is displayed using both the first thermal power display unit 6a and the second thermal power display unit 6b.

FIG. 2 is a diagram illustrating a circuit configuration of the induction heating cooker according to the first embodiment.
The induction heating cooker includes a commercial AC power source 7, a first high-frequency power circuit 8 that converts commercial AC power into high-frequency power for the first heating port, a load circuit 9 for the first heating port, and commercial AC power. A second high-frequency power supply circuit 10 that converts the high-frequency power for the second heating port and a load circuit 11 for the second heating port are provided.

  In addition, an input voltage detection unit 12 that detects input voltages to the first high frequency power supply circuit 8 and the second high frequency power supply circuit 10, a first input current detection unit 13 that detects an input current of the first high frequency power supply circuit 8, And a second input current detection unit 14 for detecting an input current of the second high frequency power supply circuit 10. Furthermore, the 1st output current detection part 15 which detects the output current of the 1st high frequency power supply circuit 8 and the 2nd output current detection part 16 which detects the output current of a 2nd high frequency power supply circuit are provided.

The first high frequency power supply circuit 8 includes a DC power supply circuit 17 that rectifies and smoothes AC power supplied from the commercial AC power supply 7, and a first inverter circuit 19 that converts the smoothed DC power into high frequency power.
The DC power supply circuit 17 includes a rectifier circuit 21 that rectifies AC power supplied from the commercial AC power supply 7, a choke coil 23 that smoothes the rectified output, and a smoothing capacitor 25.
The first inverter circuit 19 includes a high-potential side switching element 27, a low-potential side switching element 29 connected in series between output buses of the DC power supply circuit 17, and diodes 31, 33 connected in reverse parallel to the switching elements. A drive circuit 35 for alternately turning on / off the high potential side switching element 27 and the low potential side switching element 29 is provided.

  The second high frequency power supply circuit 10 has the same configuration as the first high frequency power supply circuit 9 described above.

  The load circuit 9 for the first heating port includes a first heating coil 37, a resonance capacitor 39 connected in series to the first heating coil 37, and a clamp diode 41 connected in parallel to the resonance capacitor 39. The load circuit 11 for the second heating port includes a second heating coil 38, a resonant capacitor 40 connected in series to the second heating coil 38, and a clamp diode 42 connected in parallel to the resonant capacitor 40. Prepare.

The notification unit 43 is a sound output unit that outputs sound such as a buzzer sound, and outputs a buzzer sound, for example, when changing the thermal power setting.
The control unit 44 is a control unit that controls the entire induction heating cooker, and controls the drive circuits 35 and 36 based on the thermal power set by the input setting unit 5 to control the first heating port and the second heating port. Control the heating output. Further, based on the heating power set by the input setting unit 5, the notification unit 43 outputs a buzzer sound and the display unit 6 displays the heating operation state and the like.

  In the first embodiment, an input voltage detection unit 12, a first input current detection unit 13, and a second input current detection unit 14 that can detect input power to the first inverter circuit 19 and the second inverter circuit 20 are provided. This corresponds to the power detection means of the present invention. An output voltage detector that detects the output voltages of the first inverter circuit 19 and the second inverter circuit 20 is provided separately, and the output is detected by the output voltage detector, the first output current detector 15, and the second output current detector 16. The power can be detected and used instead of the input power described in the first embodiment.

Drawing 3 is a figure showing the shape and arrangement of the 1st heating coil 37 and the 2nd heating coil 38, and is a figure when main part 1 of an induction heating cooking appliance is seen from the upper part.
As shown in FIG. 3, the first heating coil 37 disposed on the front side of the main body 1 is wound in a substantially circular shape, and the second heating coil 38 disposed on the far side is wound in a horizontally long oval shape. The 1st heating coil 37 is arrange | positioned so that it may be located in the minor axis direction of the 2nd heating coil 38 wound by the horizontally long ellipse.

  The pitch P0 of the coil conductor of the first heating coil 37 is wider than the pitch P1 of the coil conductor in the minor axis direction of the second heating coil 38 and narrower than the pitch P2 of the coil conductor in the major axis direction of the second heating coil 38. By doing so, the difference between the coil conductor density of the first heating coil 37 and the coil conductor density of the second heating coil 38 is prevented from becoming large. As a result, by supplying an equivalent high-frequency current to the first heating coil 37 and the second heating coil 38, a heating density that is not significantly different between the first heating port and the second heating port can be obtained. In particular, if the coil lead wire density of the first heating coil and the coil lead wire density of the second heating coil are substantially equal, by passing an equivalent high-frequency current through the first heating coil and the second heating coil, A substantially equivalent heating density can be obtained at the second heating port. By doing in this way, the heating unevenness can be further reduced.

  FIG. 4 is a schematic side sectional view showing the positional relationship between the first heating coil 37 and the second heating coil 38 and the cooking vessel 45. In FIG. 4, the right side of the drawing corresponds to the front side of the induction heating cooker, and the left side corresponds to the back side of the induction heating cooker.

  FIG. 4A shows a placement position when the medium-sized cooking container 45a is heated by the first heating port and the small-diameter cooking container 45b is heated by the second heating port in the individual heating mode. As shown in FIG. 4A, the cooking containers 45a and 45b are placed at positions immediately above the first heating coil 37 and the second heating coil 38, respectively.

  And if a thermal power is set by the 1st thermal power setting part 5a and the 2nd thermal power setting part 5b, the control part 44 will carry out the energization control to the 1st inverter circuit 19 and the 2nd inverter circuit 20 according to the set thermal power. The voltage is applied to the load circuit 9 and the load circuit 11. By applying this voltage, a high-frequency resonance current flows through the load circuit 9 and the load circuit 11, and a high-frequency magnetic field is generated in the first heating coil 37 and the second heating coil 38 by this current. And by this high frequency magnetic field, an eddy current is generated in the bottom part of the cooking containers 45a and 45b mounted in the 1st heating port and the 2nd heating port, and a pan is induction-heated.

  FIG. 4B shows a placement position when heating the cooking container 45c having a diameter larger than the diameter of the first heating coil 37 or the second heating coil 38 in the integrated heating mode. As shown in FIG. 4B, the cooking container 45 c is placed so as to straddle the first heating coil 37 and the second heating coil 38.

Then, the first inverter circuit 19 and the second inverter circuit 20 are driven at the same frequency, and the cooking container 45 c is heated using both the first heating coil 37 and the second heating coil 38. By doing in this way, an induction eddy current can be produced and heated in the wide area of the bottom of cooking vessel 45c.
At this time, a high-frequency current in a substantially reverse direction (phase difference greater than 90 degrees) is passed through the first heating coil 37 and the second heating coil 38. By making the high-frequency currents flowing through the first heating coil 37 and the second heating coil 38 the same frequency, it is possible to suppress the generation of the vibration sound of the audible frequency band pan due to the difference in the frequency of the magnetic field due to the current flowing through each heating coil. can do.
In addition, by causing a high frequency current in a substantially reverse direction to flow through the first heating coil 37 and the second heating coil 38, an induced eddy current due to the high frequency current flowing in the first heating coil 37 and a high frequency current flowing in the second heating coil 38. Induced eddy currents do not cancel each other out at the boundary. Since these induced eddy currents flow in substantially the same direction and strengthen each other, insufficient heating of the pot bottom portion facing between the first heating coil 37 and the second heating coil 38 can be suppressed.

FIG. 5 is a diagram for explaining the input setting unit 5 and the display unit 6 according to the first embodiment. 5A is an example of operation in the individual heating mode, FIG. 5B is an example of operation in the integrated heating mode at a low heating level, and FIG. 5C is an operation in the integrated heating mode at a high heating level. An example of
Switching between the individual heating mode and the integrated heating mode is performed by operating the changeover switch 5c in a state in which the heating by both the heating ports is stopped. The mode display lamp 6c is turned off in the individual heating mode, and is turned on in the integral heating mode.

  In the individual heating mode, the first heating power setting unit 5a performs heating on / off and heating power setting of the first heating port, and the second heating power setting unit 5b performs heating on / off and heating power setting of the second heating port. And as shown to FIG. 5 (A), according to each set thermal power, the light emitting element of the 1st thermal power display part 6a and the light emitting element of the 2nd thermal power display part 6b are lighted.

  In the integrated heating mode, the first heating power setting unit 5a is operated to set the heating power combining the first heating port and the second heating port. And the display according to the set thermal power is performed using both the 1st thermal power display part 6a and the 2nd thermal power display part 6b. As shown in FIG. 5B, when the set thermal power level is low, display is performed using only the first thermal power display unit 6a. As shown in FIG. 5C, when the set thermal power level is high, both the first thermal power display unit 6a and the second thermal power display unit 6b are turned on to display thermal power. By doing in this way, the detailed thermal power display of a wider thermal power range is attained at the time of integrated heating mode.

  In addition, although the display of the heating output level in the display part 6 is performed by making the light emitting element of the number according to the magnitude | size of the heating output light-emit, at this time, a display mode differs in individual heating mode and integral heating mode. It may be allowed. For example, the color can be changed according to the heating mode, such as turning on the red LED in the individual heating mode and turning on the yellow LED in the integrated heating mode. By doing in this way, it can make a user recognize clearly in which heating mode it is operating.

  Next, the control operation of the induction heating cooker according to the first embodiment will be described with reference to the flowcharts shown in FIGS. FIG. 6 shows a heating mode switching process for switching between the individual heating mode and the integrated heating mode in the heating stopped state.

In FIG. 6, first, it is determined whether or not the current mode set in the control unit 44 is the integrated heating mode (S101).
If it is not the integral heating mode, it is determined whether or not there is a switching input to the integral heating mode by the changeover switch 5c (S102). If there is no switching input, heating to the first thermal power setting unit 5a or the second thermal power setting unit 5b is started. It is determined whether there is an instruction (S103). If any thermal power setting unit is in a stopped state, the process returns to step S101. If any thermal power setting unit is instructed to start heating, an individual heating control process is executed (S104).

  In step S102, if there is an input to switch to the integral heating mode, the control unit 44 sets the current mode to the integral heating mode, sets the integral heating mode display, and turns on the mode display lamp 6c. (S105), the process proceeds to step S107.

  In step S101, if the integrated heating mode is selected, it is determined whether or not there is a switching input to the individual heating mode by the changeover switch 5c (S106). If there is no switching input, a heating start instruction to the first heating power setting unit 5a is determined. It is determined whether or not there is (S107). If there is no instruction to start heating, the process returns to step S101, and if there is an instruction to start heating, an integral heating control process is executed (S108).

  In step S106, when there is an input to switch to the individual heating mode, the control unit 44 sets the current heating mode to the individual heating mode, clears the integrated heating mode display, and turns off the mode display lamp 6c. (S109), the process proceeds to step S103.

  As described above, in the heating mode switching process, the heating control process in the individual heating mode or the integral heating mode is performed according to the heating mode set by the changeover switch 5c.

  Next, based on FIG. 7, the operation | movement of the separate heating mode which controls a thermal power separately by a 1st heating port and a 2nd heating port is demonstrated. The process shown in FIG. 7 is roughly a flow of first performing control on the first heating port and then performing control on the second heating port.

  First, it is determined whether or not the heating setting of the first heating port set by the first heating power setting unit 5a has been changed (S111). If there is no change, the process proceeds to step S113. If there is a change, the number of lighting elements of the first thermal power display unit 6a is changed to a number corresponding to the set thermal power, and the notification unit 43 One notification sound is generated (S112). This first notification sound is a sound indicating that the heating power setting has been changed in the individual heating mode.

  Subsequently, the input voltage, the input current, and the output current of the first heating port are detected using the input voltage detector 12, the first input current detector 13, and the first output current detector 15 (S113). Then, the detected output current is compared with a predetermined threshold value to determine whether or not the output current of the first heating port is excessive (S114).

If the output current of the first heating port is not an overcurrent in step S114, the set power set by the first heating power setting unit 5a is compared with the input power calculated from the input voltage and input current detected in step S113. (S115). If the input power is larger, the drive circuit 35 is controlled to increase the drive frequency of the first inverter circuit 19 to suppress the heating output of the first heating port (S116), and if the input power is smaller, the first inverter The drive frequency of the circuit 19 is lowered to increase the heating output of the first heating port (S117). If the set power and the input power are equal (S115), the process proceeds to step S118.
If the output current of the first heating port is an overcurrent in step S114, the process proceeds to step S116 and the output of the first inverter circuit 19 is suppressed (S116).

The control for the second heating port is performed in the same manner.
First, it is determined whether or not the heating setting of the second heating port set by the second heating power setting unit 5b has been changed (S118). If there is no change, the process proceeds to step S120. If there is a change, the number of lighting elements of the second thermal power display unit 6b is changed to a number corresponding to the set thermal power, and the notification unit 43 One notification sound is generated (S119).

  Subsequently, the input voltage, input current, and output current of the second heating port are detected using the input voltage detection unit 12, the second input current detection unit 14, and the second output current detection unit 16 (S120). Then, the detected output current is compared with a predetermined threshold value to determine whether or not the output current of the second heating port is excessive (S121).

If the output current of the second heating port is not an overcurrent in step S121, the set power set by the second heating power setting unit 5b is compared with the input power calculated from the input voltage and input current detected in step S120. (S122). If the input power is larger, the drive circuit 36 is controlled to increase the drive frequency of the second inverter circuit 20 to suppress the heating output of the second heating port (S123), and if the input power is smaller, the second inverter The drive frequency of the circuit 20 is lowered to increase the heating output of the second heating port (S124). If the set power and the input power are equal (S122), the process proceeds to step S125.
If the output current of the second heating port is an overcurrent in step S121, the process proceeds to step S123, and the output of the second inverter circuit 20 is controlled.

  Next, it is determined whether or not both the first heating port and the second heating port are instructed to stop heating by the input setting unit 5 (S125). If not instructed, the process returns to step S111 to continue the processing.

  Next, based on FIG. 8, the operation in the integrated heating mode in which the first heating port and the second heating port are integrated into one heating port and the heating power is integrally controlled will be described. In the integrated heating mode, the heating power is set by the first heating power setting unit 5a.

First, it is determined whether there is a change in the thermal power setting set by the first thermal power setting unit 5a (SS131). If there is no change, the process proceeds to step S133. If there is a change, the number of lighting elements of the first thermal power display unit 6a and the second thermal power display unit 6b is set to a number corresponding to the set integral heating thermal power. At the same time, the notification unit 43 generates a second notification sound (S132). The second notification sound is a sound indicating that the heating power setting has been changed in the integrated heating mode, and is different in tone color from the first notification sound described with reference to FIG. In this way, the user can be surely recognized the difference in the operation mode.
Further, as described above, the display of the thermal power on the display unit 6 may be different in lighting color from the display in the individual heating mode, for example. In the integrated heating mode, the first thermal power display unit 6a and the second thermal power display unit 6b may be handled as one display unit and used for thermal power display.

  Next, using the input voltage detection unit 12, the first input current detection unit 13, the second input current detection unit 14, the first output current detection unit 15, and the second output current detection unit 16, The input voltage, input current, and output current of the second heating port are detected (S133). Then, the detected output current of the first heating port (hereinafter referred to as the first output current) is compared with the output current of the second heating port (hereinafter referred to as the second output current) (S134).

  If the first output current is larger, it is determined whether or not the first output current is an overcurrent (S135). If the first output current is not an overcurrent, the power corresponding to the set heating power, the input voltage detected in step S133, and the first A comparison is made with the sum of the input power of the first heating port and the second heating port calculated from the second input current (S136).

When the sum of the input power is smaller in step S136, the drive circuit 36 is controlled to increase the output of the second inverter circuit 20 (S137), and the process proceeds to step S143. If the sum of the input powers is larger, the drive circuit 35 is controlled to suppress the output of the first inverter circuit 19 (S138), and the process proceeds to step S143. If the sum of the set power and the input power is equal, the process proceeds directly to step S143.
If the first output current is an overcurrent in step S135, the process proceeds to step S138 and the output of the first inverter circuit 19 is suppressed (S138).

  If the second output current is larger in step S134, it is determined whether the second output current is an overcurrent (S139). If the second output current is not an overcurrent, the power corresponding to the set heating power and the step S133 are determined. Is compared with the sum of the input power of the first heating port and the second heating port calculated from the input voltage and the first and second input currents detected in step S140.

If the sum of the input power is smaller in step S140, the drive circuit 35 is controlled to increase the output of the first inverter circuit 19 (S141), and the process proceeds to step S143. If the sum of the input powers is larger, the drive circuit 36 is controlled to suppress the output of the second inverter circuit 20 (S142). If the sum of the set power and the input power is equal, the process proceeds directly to step S143.
If the second output current is an overcurrent in step S139, the process proceeds to step S142 to suppress the output of the second inverter circuit 20 (S142).

  Subsequently, it is determined whether or not the first heating power setting unit 5a is instructed to stop heating (S143). If the heating stop is instructed, the integrated heating process is terminated. If the heating stop is not instructed, step S131 is performed. Return to and continue processing.

  As described above, in the integrated heating mode, the sum of the input powers of the first heating port and the second heating port is controlled to be the power corresponding to the set heating power, and the first heating coil 37 and the second heating coil 38 are controlled. Control is performed so as to suppress the difference in current flowing in the current. By doing in this way, the shift | offset | difference of the electric current which flows into the several switching element with which the 1st inverter circuit 19 and the 2nd inverter circuit 20 are provided is reduced, and it avoids that stress concentrates on a part of switching elements. Therefore, uneven heating between the heated portion by the first heating coil 37 and the heated portion by the second heating coil 38 can be suppressed.

  As described above, according to the induction heating cooker according to the first embodiment, the individual heating mode for individually controlling the heating of the plurality of heating ports, and the integrated heating mode for controlling the plurality of heating ports as one heating port. Provided. In the integrated heating mode, the first heating coil 37 and the second heating coil 38 are integrally controlled. For this reason, a pot having a diameter larger than the diameter of the first heating coil 37 or the second heating coil 38 can be heated.

  In the integrated heating mode, the sum of the input powers of the first heating port and the second heating port is controlled so as to be the power corresponding to the set heating power, and flows to the first heating coil 37 and the second heating coil 38. Control to reduce the difference in current. For this reason, the heating unevenness of the pan at the time of heating by integral heating mode can be suppressed.

  In addition, the second heating coil 38 has an elliptical shape and is arranged so that the first heating coil 37 is positioned in the minor axis direction. For this reason, when heating in the integral heating mode, since the shape of the pan bottom portion heated by the first heating coil 37 and the second heating coil 38 becomes elongated, it is possible to suppress the heating unevenness of the pan bottom from becoming large. it can.

  Moreover, it comprised so that the difference of the coil conducting wire density of the 1st heating coil 37 and the coil conducting wire density of the 2nd heating coil 38 might not become large. For this reason, it is possible to obtain a heating density that is not greatly different between the first heating port and the second heating port by flowing an equivalent high-frequency current through the first heating coil 37 and the second heating coil 38. In particular, if the coil conducting wire density of the first heating coil 37 and the coil conducting wire density of the second heating coil 38 are made substantially equal, the first heating coil and the second heating coil are caused to pass the same high frequency current, whereby the first heating coil 37 A substantially equivalent heating density can be obtained at the mouth and the second heating mouth. By doing in this way, the heating unevenness can be further reduced.

  Moreover, while operating in the individual heating mode and operating in the integrated heating mode, the display of the thermal power by the display unit 6 and the notification sound by the notification unit 43 are made different. For this reason, it can tell clearly by the user which heating mode it is operating.

  In the first embodiment, the first heating coil 37 has a substantially circular shape and the second heating coil 38 has an elliptical shape. However, as shown in FIG. 9, both heating coils have an elliptical shape. You may comprise by winding. By doing in this way, the shape of the pan bottom part heated with the 1st heating coil 37 and the 2nd heating coil 38 at the time of heating by integrated heating mode approaches circular, and further suppressing the heating nonuniformity of a pan bottom. It becomes easy.

Embodiment 2. FIG.
FIG. 10 is a flowchart of the heating control process in the integral heating mode of the induction heating cooker according to Embodiment 2 of the present invention. The control process (FIGS. 6 and 7) other than the heating control process in the induction heating cooker according to the second embodiment and the integrated heating mode is the same as in the first embodiment. Therefore, the second embodiment will be described focusing on the differences.

  In the first embodiment described above, the first heating coil 37 and the second heating coil 38 having the same coil line density shown in FIG. 3 are used, and in the integrated heating mode, each heating coil is used as shown in the flowchart of FIG. By controlling the high-frequency current to flow closer, the uneven heating of the pan was suppressed. On the other hand, in the second embodiment, in the integrated heating mode, the ratio of the input power of the first high-frequency power circuit 8 and the input power of the second high-frequency power circuit 10 is set to the area S1 of the first heating coil 37 and the second heating. By making it close to the ratio of the area S2 of the coil 38, uneven heating of the pan is suppressed.

  10, step S231 to step S233 correspond to step S131 to step S133 of FIG. 8 in the above-described second embodiment, and the same operation is performed.

In step S234, it is determined whether or not the first output current and the second output current detected in step S233 are overcurrent (S234).
If one or both of the first output current and the second output current is an overcurrent, the corresponding drive circuit 35 or drive circuit 36 is controlled to suppress the output current that is the overcurrent, and the first The output of the one inverter circuit 19 or the second inverter circuit 20 is suppressed (S235).

  If both the first output current and the second output current are not overcurrent in step S234, the power corresponding to the set thermal power, the input voltage detected in step S233, and the first and second input currents are used. The calculated input power (W1) of the first heating port and the sum of the input power (W2) of the second heating port are compared (S236).

  If the sum of the input power is larger in step S236, the ratio of the input power (W1) of the first heating port to the area (S1) of the first heating coil 37 (hereinafter, heating density W1 / S1), Comparison is made with the ratio (hereinafter referred to as heating density W2 / S2) of the input power (W2) of the second heating port to the area (S2) of the second heating coil 38 (S237).

  In step S237, when the heating density W1 / S1 is larger than the heating density W2 / S2, it can be said that the heating density of the first heating port is higher than the heating density of the second heating port. In this case, the drive circuit 35 is controlled to suppress the output of the first inverter circuit 19. By doing in this way, while reducing the sum of the input electric power of a 1st heating port and a 2nd heating port, the difference of the heating density of a 1st heating port and the heating density of a 2nd heating port can be reduced ( S238).

  If the heating density W1 / S1 is not greater than the heating density W2 / S2 in step S237, the drive circuit 36 is controlled to suppress the output of the second inverter circuit 20. By doing in this way, while reducing the sum of the input electric power of a 1st heating port and a 2nd heating port, the heating density of a 2nd heating port is reduced (S239).

In step S236, the heating density W1 / S1 of the first heating port is also compared with the heating density W2 / S2 of the second heating port even when the sum of the input power is equal to the power corresponding to the set thermal power ( S240).
If the heating density W1 / S1 of the first heating port is larger in step S240, the process proceeds to step S238 and the output of the first inverter circuit 19 is suppressed (S238). When the heating density W2 / S2 of the second heating port is larger (S240), the process proceeds to step S239 and the output of the second inverter circuit 20 is suppressed (S239). By doing in this way, the difference of the heating density of a 1st heating port and a 2nd heating port is reduced.
Moreover, if the heating density of a 1st heating port and the heating density of a 2nd heating port are equivalent by step S240, a process will be complete | finished as it is.

In step S236, when the sum of the input power is smaller than the power corresponding to the set heating power, the heating density W1 / S1 of the first heating port is compared with the heating density W2 / S2 of the second heating port ( S241).
If the heating density of the first heating port is smaller, the drive circuit 35 is controlled to increase the output of the first inverter circuit 19 (S242). When the heating density of the first heating port is not smaller than the heating density of the second heating port, the drive circuit 36 is controlled to increase the output of the second inverter circuit 20 (S243). By doing in this way, the difference of the heating density of a 1st heating port and a 2nd heating port is reduced.

  As mentioned above, according to the induction heating cooking appliance which concerns on this Embodiment 2, in the integrated heating mode which heats one pot with a some heating coil, the area of each heating coil is considered and heating of each heating coil is carried out. The driving state of each heating coil was controlled so as to suppress the difference in density. For this reason, the heating nonuniformity resulting from the difference in the heating density of each heating coil can be suppressed.

Embodiment 3 FIG.
In the third embodiment, thermal power display by the display unit in the individual heating mode and the integral heating mode will be described.
FIG. 11 is a diagram illustrating details of the thermal power display unit 60 according to the third embodiment, in which FIG. 11A is a thermal power display in the individual heating mode, and FIG. 11B is a thermal power display in the integrated heating mode. An example is shown. The thermal power display unit 60 corresponds to the first thermal power display unit 6a and the second thermal power display unit 6b of the first embodiment described above.

As shown in FIG. 11, the thermal power display unit 60 includes a plurality of light emitting elements 61 to 6n (hereinafter simply referred to as light emitting elements) arranged in series. Note that in FIG. 11, light-emitting elements that are turned on are indicated by solid lines, and light-emitting elements that are turned off are indicated by broken lines.
In the third embodiment, the light emitting element is, for example, an LED capable of displaying two colors of blue and red. When the heating port is in a heatable state, all the corresponding light emitting elements are lit in blue. Then, the number of light emitting elements corresponding to the thermal power being output is lit in red, and the number of light emitting elements lit in red is increased or decreased according to the thermal power level of each heating port.

  As shown in FIG. 11 (A), in the individual heating mode, the plurality of light emitting elements arranged in series are divided into a heating power display for the first heating port and a heating power display for the second heating port, and positioned in the middle part. Several light emitting elements to be turned off are turned off (indicated by broken lines in FIG. 11A), and the thermal power display portions of the two heating ports are separated. And the thermal power display of a 1st heating port and the thermal power display of a 2nd heating port are performed by changing the lighting color of a light emitting element.

As shown in FIG. 11B, in the integrated heating mode, the heating power display of the heating port that is integrally controlled is performed using the light emitting elements that are continuously located among the plurality of light emitting elements arranged in series. Do. In the example of FIG. 11B, some light emitting elements located at both the left and right ends are turned off and are not used. However, all the light emitting elements may be used to display the thermal power. In this way, by performing the heat display using the light emitting elements that are continuously located, it is possible to clearly notify the user that the first heating port and the second heating port operate as one heating port. .
Further, in the integrated heating mode, the display of the thermal power level may be displayed in a different color from the display of the thermal power level in the individual heating mode. For example, it can be displayed in purple by simultaneously lighting red and blue. Thus, the distinction between the heating modes can be further clarified by changing the display colors of the thermal power levels in the integrated heating mode and the individual heating mode.

As described above, according to the induction heating cooker according to the third embodiment, in the individual heating mode in which the plurality of heating ports are individually heated and controlled, and in the integrated heating mode in which the plurality of heating ports are controlled as one heating port. The fire power level is displayed using the light emitting elements arranged in series. Then, the individual heating mode and the integrated heating mode are distinguished by controlling the lighting state of the light emitting element. For this reason, while being able to make a user grasp | ascertain the present heating mode state intuitively, the thermal power level of a heating port can be notified.
Note that Embodiment 3 can be used in combination with any of the other embodiments.

Embodiment 4 FIG.
In the fourth embodiment, an embodiment in which the pan placement position is displayed on the top plate and the individual heating mode and the integral heating mode can be distinguished will be described.

  FIG. 12 is a schematic side sectional view of the induction heating cooker according to the fourth embodiment, and only the main part is shown. FIG. 13 is a top view of the top plate 2 in the individual heating mode, and FIG. 14 is a top view of the top plate 2 in the integrated heating mode.

  In FIG. 12, below the top plate 2, a first light source 46 and a first light guide 47, a second light source 48 and a second light guide 49, a third light source 50 and a third light guide 51, Is provided. The 1st light source 46, the 2nd light source 48, and the 3rd light source 50 are comprised with the light bulb, LED, etc. which emit light, and the 1st light guide 47, the 2nd light guide 49, and the 3rd light guide 51 are transparent, for example It is composed of a light guide member such as acrylic resin or transparent glass. The first light guide 47 has a shape corresponding to the outer periphery of the first heating coil 37, and the second light guide 49 has a shape corresponding to the outer periphery of the second heating coil 38. The third light guide 51 has a shape corresponding to a substantially elliptical shape surrounding the first heating coil 37 and the second heating coil 38. In the fourth embodiment, the first light source 46, the first light guide 47, the second light source 48, the second light guide 49, the third light source 50, and the third light guide 51 are the guide display of the present invention. It corresponds to the part.

The top plate 2 is configured such that at least positions corresponding to the first light guide 47, the second light guide 49, and the third light guide 51 can transmit light. The light from the first light source 46 is guided by the first light guide 47, the light from the second light source 48 is guided by the second light guide 49, and the light from the third light source 50 is guided by the third light guide 51. It is irradiated through the top plate 2.
In the induction heating cooker configured as described above, the first light source 46 in an individual heating mode in which a plurality of heating ports are individually controlled to be heated and an integrated heating mode in which the plurality of heating ports are controlled as one heating port. By switching the lighting state of the second light source 48 and the third light source 50, the placement position of the pan is displayed.

  In the individual heating mode, the first light source 46 and the second light source 48 are turned on, the third light source 50 is turned off, and the pan is placed at a position corresponding to the first heating port and the second heating port as shown in FIG. The placement position is displayed. In FIG. 13, circular displays 52 and 53 indicated by solid lines are pan placement position displays corresponding to the first heating port and the second heating port that are displayed when the first light source 46 and the second light source 48 are turned on. . Note that the circular display 54 indicated by a broken line is not displayed because the third light source 50 is turned off.

  In the integrated heating mode, the first light source 46 and the second light source 48 are turned off, and the third light source 50 is turned on, and a circular display 54 surrounding both the first heating port and the second heating port as shown in FIG. , Display the pan placement position. The circular displays 52 and 53 indicated by broken lines are not displayed because the first light source 46 and the second light source 48 are turned off.

As described above, according to the induction heating cooker according to the fourth embodiment, in the individual heating mode in which the plurality of heating ports are individually heated and controlled, and in the integrated heating mode in which the plurality of heating ports are controlled as one heating port. The state of the display that guides the placement position of the pan was changed. For this reason, the user can place the pan at an appropriate position according to the heating mode. Therefore, the shift | offset | difference of the mounting position of a pan can be suppressed and the fall of the heating efficiency accompanying a pan shift can be suppressed. Moreover, since the display state of the mounting position of the pan is switched according to the heating mode, the user can easily grasp which operation mode is in operation. Furthermore, it is possible to inform the user of an appropriate pan size according to the heating mode.
Note that Embodiment 4 can be used in combination with any of the other embodiments.

  In the above description, an induction heating cooker having two heating ports (heating coils) has been described as an example, but the number of heating ports (heating coils) is not limited to this. For example, the present invention can be applied to an induction heating cooker having three heating ports (heating coils). In this case, two of the three heating ports can be used for integral heating. All of the two heating ports may be used for integral heating.

  DESCRIPTION OF SYMBOLS 1 Main body, 2 Top plate, 3 1st mounting position display part, 4 2nd mounting position display part, 5 Input setting part, 5a 1st thermal power setting part, 5b 2nd thermal power setting part, 5c changeover switch, 6 display Part, 6a first thermal power display part, 6b second thermal power display part, 6c mode indicator lamp, 7 commercial AC power supply, 8 first high frequency power supply circuit, 9 load circuit, 10 second high frequency power supply circuit, 11 load circuit, 12 input Voltage detector, 13 First input current detector, 14 Second input current detector, 15 First output current detector, 16 Second output current detector, 17, 18 DC power supply circuit, 19 First inverter circuit, 20 Second inverter circuit, 21, 22 Rectifier circuit, 23, 24 Choke coil, 25, 26 Smoothing capacitor, 27, 28 High potential side switching element, 29, 30 Low potential side switching element, 3 , 32, 33, 34 Diode, 35 Drive circuit, 36 Drive circuit, 37 First heating coil, 38 Second heating coil, 39 Resonance capacitor, 40 Resonance capacitor, 41 Clamp diode, 42 Clamp diode, 43 Notification unit, 44 Control Part, 45 cooking container, 45a cooking container, 45b cooking container, 45c cooking container, 46 first light source, 47 first light guide, 48 second light source, 49 second light guide, 50 third light source, 51 third Light guide, 52 circular display, 53 circular display, 54 circular display, 60 thermal power display, 61-6n Light emitting element.

Claims (9)

A top plate on which the object to be heated is placed;
Two heating coils arranged under the top plate and arranged side by side with different center positions;
Two inverter circuits for supplying a high-frequency current to the heating coil,
Power detection means for detecting input power or output power of the inverter circuit;
Input setting means capable of setting the heating output and the heating operation mode;
Control means for driving and controlling the inverter circuit in response to an input from the input setting means,
The heating operation modes that can be set by the input setting means include a heating output integrated mode that controls the heating output to the two heating coils as a whole, and a heating output that individually controls the heating output to the two heating coils. Mode
One of the heating coils is configured by winding a coil conductor in a substantially elliptic shape,
The other of the heating coils is configured by winding a coil conductor in a substantially circular shape,
The pitch P0 of the coil lead wire of the heating coil wound in the substantially circular shape is wider than the pitch P1 of the coil lead wire in the short diameter direction of the heating coil wound in the substantially elliptical shape, and the coil lead wire in the long diameter direction. An induction heating cooker characterized by being narrower than the pitch P2. The induction heating cooker according to claim 1, wherein the other heating coil is disposed in a minor axis direction of the heating coil wound in the substantially elliptical shape. Provided with mode display means capable of displaying the operation status such as heating output and heating operation mode
When the heating output integrated mode is set,
The induction heating cooker according to claim 1 or 2, wherein the control means causes the mode display means to display that it is operating in a heating output integrated mode. The induction according to any one of claims 1 to 3, further comprising heating output display means for displaying the heating output in different display states according to the heating operation mode set by the input setting means. Cooking cooker. Voice output means for outputting voice when the heating output is changed by the input setting means;
The induction heating cooker according to any one of claims 1 to 4, wherein the sound output means outputs different sounds according to the heating operation mode set by the input setting means. A guide display unit that switches and displays a position on the top plate on which the object to be heated is placed according to a heating operation mode set by the input setting unit is provided. The induction heating cooker according to claim 5. When operating in the heating output integrated mode,
The control means drives and controls the two inverter circuits so that the sum of the detected power detected by the power detection means becomes the power of the heating output set by the input setting means. The induction heating cooker according to any one of claims 1 to 6. When operating in the heating output integrated mode,
The induction according to any one of claims 1 to 7, wherein the control means drives and controls the two inverter circuits so that the heating densities of the two heating coils are substantially equal to each other. Cooking cooker. The high-frequency current that flows in the inverter circuit of either one of the two heating coils is approximately the reverse direction of the high-frequency current that flows in the inverter circuit of the other heating coil. The induction heating cooker according to claim 7 or claim 8.

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