JP2020053321A - Induction heating cooker - Google Patents

Abstract

To suppress a pot made of a buoyant material from easily tilting and falling during heating of the pot.SOLUTION: Current which is made to flow through a heating coil unit 3 is controlled in accordance with movement of a heating target object 11a, and the ratio of currents to flow through first and second heating coils 3a and 3b and the frequencies thereof can be changed by the operation of first and second inverter portions 5a and 5b, whereby the magnitude of first buoyancy 12a and second buoyancy 12b can be changed. Therefore, when heating a pot such as a single-handed pot which has a grip, has the center of gravity near the grip side, and easily tilts or falls, the second buoyancy 12b of the second heating coil 3b near to the grip side of the pot is strengthened while the first buoyancy 12a of the first heating coil 3a apart from the grip is weakened, whereby it is possible to keep the balance of the pot and make the pot difficult to tilt.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to an induction heating cooker having a function of controlling buoyancy generated when heating a metal such as non-magnetic aluminum or copper, particularly for heating an object to be heated of various materials. is there.

  Conventionally, this type of induction heating cooker includes a main body constituting an outer shell, a top plate provided on an upper surface of the main body, and at least one inverter unit. The inverter unit has four switching elements and one heating coil (for example, see Patent Document 1).

  According to the above prior art, when heating an object to be heated such as aluminum or copper, high-frequency high current can be passed through the heating coil to heat the object.

JP 2008-010165 A

  However, in the above-mentioned prior art, when the object to be heated such as aluminum or copper is heated, there is a problem that the position of the center of gravity of the pan is displaced from the heating coil, and the pan is easily tilted due to the influence of buoyancy.

  An object of the present disclosure is to solve the above-described conventional problems, and to provide an induction heating cooker that can reduce the ease of tilting and falling of a pan.

  In order to solve the above-mentioned conventional problems, an induction heating cooker of the present invention includes a smoothing circuit for smoothing a power supply, and at least two or more heating coils capable of inductively heating an object to be heated by a high-frequency current. A heating coil unit, and an inverter unit supplied with power from the smoothing circuit and supplying a high-frequency current to the heating coil unit, and controls a current flowing through the heating coil in accordance with movement of the object to be heated. It is characterized by the following.

  When the object to be heated is a nonmagnetic metal material such as aluminum or copper, a first buoyancy is generated between the first heating coil of the heating coil portion and the object to be heated when the object to be heated is heated. A second buoyancy is generated between the second heating coil of the heating coil unit and the object to be heated. The movement of the object to be heated includes a displacement of the pan in which the pan moves horizontally from above the heating coil, or a tilt of the pan due to a part of the pan moving away from the top plate.

  According to this aspect, the ratio of the current flowing through the first and second heating coils and the frequency can be varied by the operations of the first and second inverter units of the inverter unit. Thereby, the magnitudes of the first buoyancy and the second buoyancy can be varied.

  Since the magnitudes of the first buoyancy and the second buoyancy can be varied, there is a handle such as a one-handed pot that is the object to be heated, the center of gravity is close to the handle side, and the pot is easily tilted and easily falls down. At this time, the first buoyancy of the first heating coil close to the handle side of the pan is increased, and the second buoyancy of the second heating coil away from the handle is reduced, thereby maintaining the balance of the pan, Can be hardly inclined.

Block diagram of induction heating cooker according to Embodiment 1 Block diagram of induction heating cooker according to Embodiment 1 Block diagram of induction heating cooker according to Embodiment 2. Block diagram of induction heating cooker according to Embodiment 2. Operation transition diagram of the induction heating cooker executed in the second embodiment Operation transition diagram of the induction heating cooker executed in the second embodiment Block diagram of induction heating cooker according to Embodiment 3.

  According to a first aspect of the present invention, power is supplied from a smoothing circuit configured to smooth a power supply, a heating coil unit including at least two or more heating coils capable of inductively heating an object to be heated by a high-frequency current, and a smoothing circuit. An inverter unit for supplying a high-frequency current to the heating coil unit, wherein the current flowing through the heating coil is controlled according to the movement of the object to be heated, thereby controlling the currents of the plurality of heating coils. Then, the distribution of buoyancy generated between the heating coil and the object to be heated can be adjusted by adjusting the buoyancy distribution of the pan, and the pan can be heated without moving by the buoyancy.

  In the second invention, in particular, in the first invention, the buoyancy of the object to be heated is controlled by controlling a current flowing through the heating coil so as to decrease the buoyancy generated in the object to be heated as the distance from the center of gravity of the object to be heated decreases. The generation of buoyancy at the end of the object to be heated which is easily affected can be reduced.

  According to a third aspect of the present invention, in particular, the heating coil unit according to the first or the second aspect of the present invention includes a first heating coil and a second heating coil that are divided and arranged in the front-rear direction. Thus, it is possible to provide an easy-to-use induction heating cooker.

  Usually, when a user cooks using a pot with a handle, the handle is often arranged in front of the user, and the arrangement of the first heating coil and the second heating coil of the heating coil unit. However, since one is located closer to the user and the other is located farther from the user, the opposite side of the handle (that is, the back side of the induction heating cooker) where the object to be heated is likely to generate buoyancy. Buoyancy is easier to control.

  In addition, since the magnitude of buoyancy can be changed before and after, there is a handle such as a one-handed pot that is the object to be heated, the center of gravity is close to the handle side, it is easy to tilt and it is easy to fall down By increasing the first buoyancy of the first heating coil near the handle side and weakening the second buoyancy of the second heating coil away from the handle, maintaining the balance of the pan and making the pan less inclined Can be.

  According to a fourth aspect, in the third aspect, when it is detected that the object to be heated has moved from the top plate, the buoyancy is controlled by controlling a current flowing through a heating coil near the side moved from the top plate. It is possible to suppress the movement of the pot by reducing it.

  According to a fifth aspect, in the third or fourth aspect, when it is detected that the object to be heated has moved from the top plate, the heating power of the heating coil far from the side moved from the top plate is increased. It is possible to make the pot difficult to move even with high thermal power while suppressing buoyancy.

According to a sixth aspect of the present invention, in any one of the first to fifth aspects, the first heating coil and the second heating coil are arranged at positions where they mutually interfere with each other, and the first inverter unit and the second inverter coil are connected to each other. By controlling the inverter unit, a third heating unit and a third buoyancy are generated between the first heating coil and the second heating coil, and the object to be heated is controlled by buoyancy at three points. By being characterized by being harder to move and capable of being heated with higher heating power, by supporting the pot at three points, it is possible to generate higher heating power while suppressing the movement of the pot.

  Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the following description, the same or corresponding parts have the same reference characters allotted, and overlapping description will be omitted. The present invention is not limited by the embodiment.

(Embodiment 1)
FIG. 1 is a block diagram of an induction heating cooker 1a according to Embodiment 1 of the present disclosure. As shown in FIG. 1, the induction heating cooker 1a includes a top plate 2 provided on an upper surface of a main body constituting an outer shell, an inverter unit 5a, an inverter unit 5b, and an inverter unit 5a provided below the top plate 2. And a smoothing circuit 6 for supplying DC power to the inverter unit 5b, and a control unit 10 for controlling operations of the inverter unit 5a and the inverter unit 5b.

  The top plate 2 is made of an electrical insulator such as glass. The inverter unit 5a includes a heating coil unit 3a, a resonance capacitor 8a, a switching element 7a, and a switching element 7b. The inverter unit 5b includes a heating coil unit 3b, a resonance capacitor 8b, a switching element 7c, and a switching element 7d. .

  The heating coil unit 3a and the heating coil unit 3b are arranged at positions where the same object to be heated can be heated, and the heating coil 3a and the heating coil 3b correspond to first and second heating coils, respectively.

  The smoothing circuit 6 has a diode bridge, a capacitor, and a coil, which are full-wave rectifier circuits. The smoothing circuit 6 rectifies the AC voltage supplied from the commercial power supply 4 and smoothes the rectified DC voltage. The smoothing circuit 6 corresponds to a DC power supply.

  The switching element 7a and the switching element 7b are connected in series between output terminals of the DC power supply. The switching element 7a is arranged on the high potential side, and the switching element 7b is arranged on the low potential side. The switching element 7c and the switching element 7d are connected in series between output terminals of the DC power supply. The switching element 7c is arranged on the high potential side, and the switching element 7d is arranged on the low potential side.

  The switching element 7a, the switching element 7b, the switching element 7c, and the switching element 7d are configured by an IGBT or the like, and include a diode connected in the reverse direction.

  One ends of the resonance capacitor 8a and the resonance capacitor 8b are connected to the low potential side of the output terminal of the DC power supply. The other end of the resonance capacitor 8a is connected to the inside terminal of the heating coil 3a. The other end of the resonance capacitor 8b is connected to the inside terminal of the heating coil 3b. An outer terminal of the heating coil 3a is connected to a connection point between the switching element 7a and the switching element 7b. An outer terminal of the heating coil 3b is connected to a connection point of the switching element 7c and the switching element 7d. The heating coil 3a and the resonance capacitor 8a form a resonance circuit 9a. The heating coil 3b and the resonance capacitor 8b form a resonance circuit 9b.

  The resonance circuits 9a and 9b correspond to first and second resonance circuits, respectively.

The control unit 10 outputs a control signal to each of the switching elements 7a, 7b, 7c, and 7d to control the switching elements 7a, 7b, 7c, and 7d. The control unit 10 controls the heating output by controlling the frequency, the duty ratio, and the phase of the control signal.

  The inverter unit 5a and the inverter unit 5b generate a high-frequency current from the AC voltage supplied from the commercial power supply 4, output the generated high-frequency current to the heating coil unit 3a and the heating coil unit 3b, and output the high-frequency current to the heating coil unit 3a and the heating coil unit 3a. The coil unit 3b is driven. The heating coil unit 3a and the heating coil unit 3b perform induction heating on the pan, which is the object to be heated 11a, mounted on the top plate 2 by high-frequency current. Then, by the operation of the first and second inverter units 5a and 5b of the inverter unit, it is possible to change the ratio and frequency of the current flowing through the first and second heating coils 3a and 3b. Thereby, the magnitudes of the first buoyancy 12a and the second buoyancy 12b can be changed.

  When performing induction heating, the first heating coil 3a and the second heating coil 3b of the heating coil unit 3 are arranged at positions where the same object to be heated 11a can be heated, and the object to be heated 11a is heated. A first buoyancy 12a is generated between the first heating coil 3a and the object to be heated 11a, and a second buoyancy 12b is generated between the second heating coil 3b and the object to be heated 11a. . Specifically, a buoyancy 12a is generated between the heating coil unit 3a and the object to be heated 11a, and a buoyancy 12b is generated between the heating coil unit 3b and the object to be heated 11a.

  The switching elements 7a, 7b, 7c, and 7d correspond to first, second, third, and fourth switching elements, respectively. The resonance capacitor 8a and the resonance capacitor 8b correspond to a first resonance capacitor and a second resonance capacitor, respectively. The buoyancy 12a and the buoyancy 12b correspond to a first buoyancy and a second buoyancy, respectively.

  In the present embodiment, when the object to be heated 11a moves in a direction far away from the top plate 2 on the side of the heating coil, the output of the inverter unit 5 is reduced to reduce the buoyancy, whereby the object to be heated 11a is reduced. Movement can be suppressed.

  The movement of the object to be heated 11a is detected by providing an electric characteristic detecting means for detecting a change in the electric characteristic of the voltage or the current of the resonance circuit, and detecting the change in the electric characteristic of the voltage or the current. May be detected, or the top plate 2 may be provided with an electrode, and the change of the electrode may be detected to detect that the object to be heated 11a has left. Further, the separation of the object to be heated 11a may be detected using a pressure sensor, a temperature sensor, a motion sensor, or the like.

  As described above, the buoyancy 12a and the buoyancy 12b can be increased or decreased by controlling the frequency and the duty ratio of the inverters 5a and 5b in accordance with the movement of the object to be heated 11a. You can do it.

  The pot can be heated without moving by buoyancy. The movement of the object to be heated 11a includes a displacement of the pan in which the pan moves horizontally, or a tilt of the pan due to a part of the pan separating from the top plate 2.

  FIG. 2 is a block diagram of the induction heating cooker according to the present embodiment. In the present embodiment, the arrangement of the heating coil 3a and the heating coil 3b is arranged before and after (front side and back side) when viewed from the direction of the user 13.

  Usually, when a user cooks using a one-handed pan with a handle, cooking is often performed such that the handle is arranged on the user side. For this reason, the one-handed pan is affected by the weight of the handle, and the back side of the pan is easily affected by buoyancy when viewed from the user and tilts.

  For this reason, in the present embodiment, the heating object 3b is received by arranging the heating coil 3a and the heating coil 3b in the front and back, one of which is arranged near the user and the other is arranged far from the user. The structure is such that it is easy to control the buoyancy on the opposite side of the handle where buoyancy is likely to occur (that is, on the back side of the induction heating cooker 1a).

  Thus, when the movement of the object to be heated 11b is detected, the generation of the buoyancy 12a can be suppressed by weakening the current on the heating coil 3a side.

  FIG. 3 is a block diagram of the induction heating cooker according to the present embodiment. FIG. 3 also illustrates a case where a one-handed pan with a handle is used as the object to be heated 11b. The control unit 10 controls the buoyancy 12b closer to the center of gravity of the object to be heated 11b so as to increase. By doing so, the buoyancy 12b becomes relatively larger than the buoyancy 12a, so that the thermal power can be increased while suppressing the influence of the buoyancy 12a.

  Further, in the present embodiment, one end of the resonance capacitor 8a is connected to the low voltage side of the DC power supply, but may be connected to the high voltage side of the DC power supply, or the number of resonance capacitors may be increased to increase the high voltage side. And the low voltage side.

  Also, one end of the resonance capacitor 8b is connected to the low voltage side of the DC power supply, but it may be connected to the high voltage side of the DC power supply, or the number of resonance capacitors may be increased to increase both the high voltage side and the low voltage side. May be connected.

  The inner terminals of the heating coils 3a and 3b are connected to the resonance capacitors 8a and 8b, and the outer terminals are connected to the connection points of the switching elements 7a, 7b, 7c and 7d. The outer terminals of the heating coil 3a and the heating coil 3b may be connected to the resonance capacitor 8a and the resonance capacitor 8b, and the inner terminal may be connected to a connection point of the switching element 7a, the switching element 7b, the switching element 7c, and the switching element 7d.

  The position of the heating coil 3a and the position of the resonance capacitor 8a may be reversed, or the position of the heating coil 3b and the position of the resonance capacitor 8b may be reversed.

  The heating coils 3a, 3b may have the same number of turns or different numbers of turns. The heating coils 3a, 3b may have the same shape or different shapes.

The connection point between the heating coil 3a and the resonance capacitor 8a and the connection point between the heating coil 3b and the resonance capacitor 8b are not connected, but may be connected. The resonance circuit 9a includes the heating coil 3a and the resonance capacitor 8a. The resonance capacitor 8c may be added in series between the heating coil 3a and the connection point between the switching element 7a and the switching element 7b.

  Although the resonance circuit 9b includes the heating coil 3b and the resonance capacitor 8b, a resonance capacitor 8d may be added in series between the heating coil 3b and a connection point between the switching element 7c and the switching element 7d.

(Embodiment 2)
FIG. 4 is a block diagram of the induction heating cooker 1b according to the present embodiment. Hereinafter, Embodiment 2 of the present disclosure will be described.

  As shown in FIG. 4, the present embodiment is different from the first embodiment in that it has an electric characteristic detecting unit 14a for detecting the electric characteristic of the inverter unit 5a and an electric characteristic detecting unit 14b for detecting the electric characteristic of the inverter unit 5b. Different from the heating cooker 1a. Other configurations are the same as those of the induction heating cooker 1a according to the first to third embodiments.

  The control unit 10 detects the movement of the object to be heated 11b from the electric characteristic detecting means 14a and the electric characteristic detecting means 14b, and reduces the buoyancy 12 of the one that has detected that the object to be heated 11b has largely moved away. The inverter unit 5 is controlled.

  According to the present embodiment, the movement of the object to be heated 11b is detected, and the buoyancy 12 of the portion where the object to be heated 11b is easily movable is accurately and quickly reduced, so that the movement of the object to be heated 11b is further suppressed and heating is performed. Can be done.

  FIG. 5 shows an example of an operation transition of the inverter unit 5 when the object to be heated 11b moves.

  As shown in FIG. 5, when the object to be heated 11b moves far away on the heating coil 3a side, this is detected by the electric characteristic detecting means 14a and the electric characteristic detecting means 14b, and the output of the inverter 5a is output. By lowering the buoyancy 12a, the movement of the object to be heated 11b can be suppressed.

  FIG. 6 is an operation transition diagram illustrating an example of the operation of the inverter unit 5 when the object to be heated 11b moves.

  The control unit 10 detects the movement of the object to be heated 11b from the electric characteristic detection unit 14a and the electric characteristic detection unit 14b, and lowers the thermal power of the inverter unit 5a that has detected that the object to be heated 11b has largely moved away. The inverter unit 5 is controlled so that the buoyancy 12 is reduced and the thermal power is increased only by the other inverter unit 5b.

  As described above, by detecting the movement of the object to be heated 11b and accurately and quickly reducing the buoyancy 12 of the portion where the object to be heated 11b is easy to move, the movement of the object to be heated 11b can be further suppressed and heating can be performed. Further, by increasing only the buoyancy of a portion where the object to be heated 11b is difficult to move, it is possible to suppress the movement of the object to be heated 11b and to increase the thermal power.

  FIG. 6 shows a transition diagram of an operation example of the inverter unit 5 when the object to be heated 11b moves.

  As shown in FIG. 6, when the object to be heated 11b moves far away on the heating coil 3a side, this is detected by the electric characteristic detecting means 14a and the electric characteristic detecting means 14b, and the output of the inverter 5a is output. By lowering the buoyancy 12a, the movement of the object to be heated 11b is suppressed. Further, by increasing only the output of the other inverter unit 5b, it is possible to increase the thermal power while suppressing the movement of the object to be heated.

  As described above, in the present embodiment, the electric characteristic detecting means 14a and 14b for detecting the change in the electric characteristic of the voltage or the current of the resonance circuit are provided, and the change in the electric characteristic of the voltage or the current is detected. The movement of the object to be heated 11b is detected. Thereby, when the object to be heated 11b moves in a direction far away from the top plate 2 on the side of the heating coil, the output of the inverter unit 5 is reduced to reduce the buoyancy, thereby suppressing the movement of the object to be heated 11b. I can do it.

  In the present embodiment, the case where the object to be heated 11a is inclined has been described as an example. However, the movement of the object to be heated 11a is controlled in the same manner even if the pan is horizontally displaced. In this way, the displacement of the pot can be suppressed.

(Embodiment 3)
FIG. 7 is a block diagram of the induction heating cooker according to the present embodiment. Hereinafter, Embodiment 6 of the present disclosure will be described.

  As shown in FIG. 7, in the present embodiment, the heating coil 3a and the heating coil 3b are arranged at positions where they mutually interfere with each other, and by controlling the inverter unit 5a and the inverter unit 5b, the place where the buoyancy 12a is generated The point that buoyancy 12c is generated between places where buoyancy 12b is generated is different from any of the first to fifth embodiments in the object to be heated 11c. Other configurations are the same as those of the induction heating cookers according to the first to fifth embodiments.

  According to the present embodiment, by generating the buoyancy 12c, for example, by using the buoyancy 12c in a pot having a convex center at the bottom of the pot like the object to be heated 11c shown in FIG. Buoyancy can be generated near the center of gravity of the object to be heated 11c, and the pot is supported at three points of buoyancy 12a, buoyancy 12b, and buoyancy 12c, thereby suppressing the movement of the object to be heated and increasing the heating power. Can be generated.

  The present disclosure is applicable to home or business induction heating cookers.

1a, 1b induction heating cooker 2 top plate 3 heating coil section 3a, 3b heating coil section 4 commercial power supply 5 inverter section 5a, 5b inverter section 6 smoothing circuit 7a, 7b, 7c, 7d switching element 8a, 8b resonance capacitor 9a, 9b Resonant circuit 10 Control unit 11 Heated object 11a, 11b, 11c Heated object 12 Buoyancy 13 User 14a, 14b Electrical characteristic detecting means

Claims (6)

A smoothing circuit for smoothing the power supply,
A heating coil unit comprising at least two or more heating coils capable of inductively heating an object to be heated by a high-frequency current;
An inverter unit supplied with power from the smoothing circuit and supplying a high-frequency current to the heating coil unit;
With
According to the movement of the object to be heated,
An induction heating cooker characterized by controlling a current flowing through the heating coil section. 2. The induction heating cooker according to claim 1, wherein a current flowing through the heating coil is controlled so that buoyancy generated in the heated object is reduced as the distance from the center of gravity of the heated object increases. 3. The induction heating cooker according to claim 1, wherein the heating coil unit includes a first heating coil and a second heating coil divided and arranged in the front-rear direction. 4. The induction heating cooker according to claim 3, wherein when detecting that the object to be heated has moved from the top plate, a current flowing in a heating coil near a side moved from the top plate is controlled. 5. The induction heating cooker according to claim 3 or 4, wherein when detecting that the object to be heated has moved from the top plate, the heating power of a heating coil far from the side moved from the top plate is increased. By arranging the first heating coil and the second heating coil at positions where they interfere with each other and controlling the first inverter unit and the second inverter unit, the first heating coil and the second heating coil The third heating unit and the third buoyancy are generated during, and the object to be heated is harder to move by controlling by the buoyancy at three points, and can be heated with higher heating power. The induction heating cooker according to any one of claims 1 to 5.

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