JP2011258338A - Heating cooker - Google Patents

Abstract

The load side is provided with a plurality of heating coils equivalently having the same inductance and resistance, and a high frequency power is supplied from a common drive circuit to a target heating coil, which is smaller and less expensive than the conventional one. Provided is a cooking device that can reduce the cost of the cooking device body by using a drive circuit.
In a heating cooker according to the present invention, a central IH heating unit and an oven heating unit share a single inverter. Therefore, compared to a cooking device in which an original inverter is provided for each of these two heating units 22 and 28, the power supply circuit including the inverter can be made smaller, the number of parts can be reduced, and the manufacturing cost can be reduced.
[Selection] Figure 2

Description

  The present invention relates to an electromagnetic induction heating cooker.

  Conventionally, a microwave oven function that radiates microwaves from a magnetron to inductively heat food, and a high-frequency current is supplied to an electromagnetic induction heating coil to inductively heat the walls of the heating chamber, and the radiant heat from the heated walls causes food to be heated. There has been proposed a combined cooking device having two functions of an electric oven function that heats (see, for example, Patent Document 1).

  According to this composite heating cooker, it is possible to switch between a state in which high-frequency power is supplied from the voltage resonance type inverter circuit to the induction heating coil and a state in which a high voltage is supplied to the magnetron by using the changeover switch.

JP-A-62-93893

  However, the combined cooking device described in Patent Document 1 requires a switching element having a very high breakdown voltage when a voltage resonance inverter is used when the input voltage is a high voltage of AC 200V, for example. Therefore, the switching elements that can be used are limited to expensive ones, and the cooking device becomes expensive.

  In addition, the induction heating coil is equivalent to inductance and resistance (LR load) on the load side, whereas the magnetron is equivalent to mainly resistive load instead of inductance load, so it can be shared when viewed from the control side. There is a circuit part that cannot be shared with the circuit part. As a result, it is difficult to simplify control and circuit design.

  Therefore, the present invention has been made to solve such problems, the purpose of which comprises a plurality of heating coils whose load side is equivalently the same inductance and resistance, A heating cooker that supplies high-frequency power to a target heating coil from a common drive circuit, and that can reduce the cost of the heating cooker body by using a drive circuit that is smaller and less expensive than the conventional drive circuit. Is to provide.

  The cooking device of the present invention includes a casing, a first heating coil disposed on the upper surface of the casing, a heating chamber having a heated portion made of a metal magnetic material at least partially, and the vicinity of the heated portion And a switching means for selectively connecting one of the first heating coil and the second heating coil to the power supply section. .

  According to the heating cooker of the present invention, since the inverter that supplies power to the first and second heating coils whose load side is equivalently the same reactor and resistor is shared, the inverter circuit is reduced in size, weight, and heating. The cost of the cooking device can be reduced, and the control and circuit design can be simplified by sharing the control circuit.

It is a schematic perspective view which shows the heating cooker main body which concerns on embodiment of this invention. It is a schematic block diagram of the heating cooker of Embodiment 1. FIG. It is a figure which shows the circuit structure of the heating cooker of Embodiment 1. FIG. It is a figure which shows the circuit structure of another heating cooker which concerns on Embodiment 1. FIG. It is a schematic block diagram of the heating cooker of Embodiment 2. FIG. It is a figure which shows the circuit structure of the heating cooker of Embodiment 2. FIG. It is a schematic block diagram of the heating cooker of Embodiment 3. It is a schematic block diagram of another heating cooker which concerns on Embodiment 3. FIG. It is a figure which shows the circuit structure of the heating cooker of Embodiment 4. FIG. It is a figure which shows the circuit structure of the heating cooker of Embodiment 5. FIG. It is a longitudinal cross-sectional view of the heating chamber of the heating cooker which concerns on Embodiment 7. FIG. It is a perspective view of the heating chamber of the cooking-by-heating machine concerning Embodiment 7.

  Hereinafter, a combined induction heating cooker according to an embodiment of the present invention will be described with reference to the accompanying drawings. In the following description, terms indicating the direction and position (for example, “upward” and “downward”) are used for convenience, but these are for facilitating the understanding of the invention. The technical scope should not be interpreted in a limited way. Moreover, in the following description, the same code | symbol is attached | subjected to the same or similar structure contained in several embodiment.

Embodiment 1 FIG.
As shown in FIG. 1, a composite induction heating cooker (hereinafter referred to as “heating cooker”) 1 according to Embodiment 1 has a box-shaped casing (cooker body) 10. The upper surface of the housing 10 is covered with a top plate 12 made of heat-resistant glass. An upper surface operation unit 14 and a ventilation unit 16 (for example, an intake port 18 and an exhaust port 20) are provided on the front side and the back side of the top plate 12, respectively. Three IH heating units (a central IH heating unit 22, a left IH heating unit 24, and a right IH heating unit 26) are arranged in a central region of the housing 10 (a region between the upper surface operation unit 14 and the ventilation unit 16). ing. In the first embodiment, the left and right IH heating units 24 and 26 are arranged on the front side, and the central IH heating unit 22 is arranged on the back side, but these three IH heating units 22, 24, and 26 are arranged. May be arranged in a line in the left-right direction.

  An oven heating unit 28 is provided at the center of the housing 10. The oven heating unit 28 includes a heating chamber (heating chamber) 30 (see FIG. 2) opened on the front surface (side wall on the front side) of the housing 10. The opening of the heating chamber 30 can be opened and closed by a door 32. More specifically, the door 32 is detachably connected to a pair of grill rails that can be pulled out along a pair of guide portions fixed to the left and right in the heating chamber 30 as in a normal oven heating unit. . In addition, the grille can be attached to and detached from the pair of grille rails.

  Each of the IH heating units 22, 24, and 26 includes heating coils 34, 36, and 38 disposed under the top plate 12.

  As shown in FIG. 2, the ceiling wall 40 and the bottom wall 42 constituting the heating chamber 30 of the oven heating unit 28 are formed of plates made of a metal magnetic material (for example, iron), and the ceiling wall 40 and the bottom wall are formed. Heating coils 44 and 46 are disposed behind 42.

  Returning to FIG. 1, the upper surface operation unit 14 is a group of operation switches for the central IH heating unit 22, the left IH heating unit 24, and the right IH heating unit 26 (on / off switches 48, 50, 52, thermal power adjustment switch, timer switch). And an operation switch group (on / off switch 54, heating power adjustment switch, timer switch) of the oven heating section 28 are provided. A display unit 56 is arranged on the central upper surface of the housing 10 covered with the top plate 12, and this appears through the top plate 12. For example, the display unit 56 includes a high temperature caution lamp that is turned on when the IH heating units 22, 24, and 26 are in a high temperature state.

  On the front surface of the housing 10, a left front operation unit 58 and a right front operation unit 60 are disposed on both sides of the door 32, respectively. These left and right front operation units 58 and 60 include a group of operation switches (on / off switches 62 and 64, heating power adjustment switches) of the left and right IH heating units 24 and 26.

  Referring back to FIG. 2, the heating cooker 1 has a power supply unit (power supply circuit) 66. The power supply unit 66 includes an IH / oven changeover switch (hereinafter referred to as “changeover switch”) 68 serving as changeover means. The changeover switch 68 is composed of a switching element such as a relay or a power semiconductor, for example, and is movable so as to selectively contact only two contact terminals 70 and 72 and only one of these two contact terminals 70 and 72. A contact 74 is provided. In the first embodiment, one contact terminal 70 is connected to the heating coil 34 of the central IH heating unit 22, the other contact terminal 72 is connected to the heating coils 44 and 46 of the oven heating unit 28, and the movable contact 74 is connected. The inverter 76 is connected. The movable contact 74 connects the heating coil 34 of the central IH heating unit 22 to the inverter 76 and also disconnects the heating coils 44 and 46 of the oven heating unit 28 from the inverter 76, and the heating coil 44 of the oven heating unit 28. 46 is connected to the inverter 76, and the heating coil 34 of the central IH heating unit 22 can be moved between the dotted line positions where the heating coil 34 is cut off from the inverter 76. The movable contact 74 is moved from the solid line position to the dotted line position or from the dotted line position to the solid line position based on a signal output from the switch switching control unit 78. The movable contact 74 takes a solid line position when the off switch 48 is in the “on” state, and takes a dotted line position when the oven heating unit on / off switch 54 is in the “on” state. In the first embodiment, the movable contact 74 is set at a position indicated by a solid line in the initial state.

  As shown in FIG. 3, in the first embodiment, the inverter 76 is a half-bridge inverter that converts an alternating current into a direct current and then converts the direct current into a high-frequency alternating current. The inverter 76 is connected to the DC power supply unit 80 of the power supply unit 66. The DC power supply unit 80 is connected to an AC power supply 82. The AC power source 82 is a single-phase or three-phase commercial AC power source. The AC power source 82 is connected to a rectifier circuit 84 that full-wave rectifies the AC current output from the AC power source 82. The rectifier circuit 84 is connected to a smoothing capacitor 86 that smoothes the DC voltage that has been full-wave rectified by the rectifier circuit 84. A pair of switching elements 88 (switching elements 90 and 92) included in the inverter 76 is connected in series to the DC power supply unit 80. A series resonance circuit including a changeover switch 68, heating coils 34, 44, and 46 and a resonance capacitor 94 is connected between the switching elements 90 and 92. Further, the switching elements 90 and 92 are connected to the control unit 96, and the switching elements 90 and 92 are alternately turned on and off based on a signal output from the control unit 96 so that a desired high frequency is supplied to the heating coil 34 or 44. , 46 is applied. The heating coil 34 and the heating coils 44 and 46 are designed so that the impedance of the heating coil 34 and the combined impedance of the heating coils 44 and 46 connected in parallel are substantially equal.

  Although not shown, among the three IH heating units 22, 24 and 26, the power circuits of the left IH heating unit 24 and the right IH heating unit 26 have their own power supply units, and each power supply unit has a predetermined high frequency. An electric current can be applied to the heating coils 36 and 38.

  Operation | movement of the heating cooker 1 comprised in this way is demonstrated. Usually, the changeover switch 68 is in the position of the solid line shown in FIGS. 2 and 3 and connects the central IH heating unit 22 to the inverter 76. From this state, when the ON / OFF switch of the central IH heating unit 22 in the upper surface operation unit 14 is turned “ON”, the output from the AC power supply 82 (AC) is converted to DC and then output from the control unit 96. By the on / off operation of the switching elements 90 and 92 based on the above, the direct current is converted again into a high frequency alternating current, and a high frequency current is applied to the heating coil 34 of the central IH heating unit 22. As a result, if a cooking container including a magnetic metal member is placed on the central IH heating unit 22, an eddy current is generated in the magnetic metal member, and the cooking container is induction-heated by the Joule heat.

  When the ON / OFF switch of the oven heating unit 28 in the upper surface operation unit 14 is set to the ON state, the changeover switch 68 is switched from the solid line position to the dotted line position based on a signal from the switch change control unit 78. At the same time, the central IH heating unit 22 is disconnected from the inverter 76. As a result, a high frequency current is applied to the heating coils 44 and 46 of the oven heating unit 28. Thereby, an eddy current is generated in the ceiling wall 40 and the bottom wall 42 of the heating chamber 30, and the entire ceiling wall 40 and the bottom wall 42 are uniformly heated by the Joule heat. Therefore, if a heating target (for example, food) is placed on the grill of the oven heating chamber 30, the heating target is uniformly and uniformly heated by the radiant heat of the heated ceiling wall 40 and bottom wall 42. Moreover, since there is no heating member such as a sheathed heater inside the oven heating chamber 30, a large effective volume (cooking space) can be secured inside the heating chamber 30 and the inside of the heating chamber 30 can be easily cleaned.

  According to the cooking device 1 of the first embodiment configured as described above, the central IH heating unit 22 and the oven heating unit 28 share one inverter 76. Therefore, compared with the heating cooker in which these two heating units 22 and 28 are each provided with an original inverter, the heating cooker according to Embodiment 1 can reduce the power supply circuit including the inverter and reduce the number of components. Manufacturing costs can be reduced.

  Further, as shown in FIG. 3, since the heating coil 34 of the central IH heating unit 22 and the heating coils 44 and 46 of the oven heating unit 28 are both loads, they have a series load of inductance and resistance on the equivalent circuit. Constitute. In addition, since the impedance of the heating coil 34 of the central IH heating unit 22 and the combined impedance of the heating coils 44 and 46 of the oven heating unit 28 can be designed to be substantially equal, the load on the inverter 76 does not change before and after the changeover switch 68 is switched. Therefore, the control circuit of the central IH heating unit 22 and the control circuit of the oven heating unit 28 can be shared, and as a result, the design of the control circuit is simplified.

  Furthermore, since the inverter 76 is formed of a current resonance type half-bridge inverter, the voltage applied to the switching elements 90 and 92 can be lowered. As a result, since a small, lightweight and inexpensive low withstand voltage switching element can be used, the power supply circuit including the inverter can be reduced in size, and the manufacturing cost of the cooking device 1 can be reduced.

  Although the current resonance type herb bridge inverter is employed in the first embodiment shown in FIGS. 2 and 3, a current resonance type full bridge inverter may be used instead. In this embodiment, as shown in FIG. 4, the inverter 176 has two pairs of switching elements 188 a and 188 b connected in parallel to the rectifier circuit 84. As shown in the figure, the first switching element pair 188a shown on the left side of the figure has two switching elements 190a and 192a connected in series, and the second switching element pair 188b shown on the right side of the figure is connected in series. Two switching elements 190b and 192b are provided. And between the output points of the switching elements 190a and 192a and between the output points of the switching elements 190b and 192b, the changeover switch 68, the heating coil 34 of the central IH heating unit 22 and the heating coils 44 and 46 of the oven heating unit 28, A series resonance circuit including a resonance capacitor 94 is connected. According to the cooking device 1 configured as described above, according to the output from the control unit 96, the switching elements 190a and 192b are on, the switching elements 190b and 192a are off, and the switching elements 190a and 192b are off, The switching elements 190b and 192a are alternately turned on, and a predetermined high-frequency current is applied to the heating coil 34 or the heating coils 44 and 46. Also in this embodiment, it is preferable that the heating coils 34, 44 and 46 are designed so that the impedance of the heating coil 34 and the combined impedance of the heating coils 44 and 46 connected in parallel are substantially equal.

  In the above description, the power circuit of the central IH heating unit 22 and the power circuit of the oven heating unit 28 are shared. Instead, the power circuit of the left IH heating unit 24 or the right IH heating unit 26 is used as the power source of the oven heating unit 28. It may be shared with a circuit. Moreover, in Embodiment 1, although the ceiling wall 40 and the bottom wall 42 of the heating chamber 30 were formed with the magnetic metal material, both or one of the back side wall 98 of the heating chamber 30, and the left and right side walls 100 (see FIG. 2). One of them is made of the same magnetic metal material, and a heating coil (not shown) is arranged behind the side wall made of the magnetic metal material, and these heating coils are connected to the power supply circuit together with the upper and lower heating coils 44 and 46. May be. In this case, not only can the temperature in the heating chamber 30 be kept more uniform, but also the object to be heated can be heated from the lateral direction. Furthermore, in Embodiment 1, although the heating coils 44 and 46 of the oven heating unit 28 are connected in parallel, they may be connected in series, and when four or more coils are arranged, they can be connected in series and parallel. It is. Also in these cases, it is preferable that the heating coils 34, 44, and 46 are designed so that the impedance of the heating coil 34 and the combined impedance of the heating coils 44 and 46 connected in parallel or in series and parallel are substantially equal.

Embodiment 2. FIG.
A cooking device 1 according to Embodiment 2 will be described. In the first embodiment, the power supply unit of any one of the three IH heating units is shared with the power supply unit of the oven heating unit. However, in the second embodiment, two arbitrarily selected IH heating units are used. The power supply unit of the unit is shared with the power supply unit of the oven heating unit.

  In the heating cooker 1 according to the second embodiment, the inverters of the left IH heating unit 24 and the right IH heating unit 26 are used as the inverter of the oven heating unit 28. More specifically, referring to FIG. 5, the power supply unit 266 has two changeover switches (a first changeover switch 268a and a second changeover switch 268b). In the first changeover switch 268a, one contact terminal 270a is connected to the heating coil 36 of the left IH heating unit 24, and the other contact terminal 272a is connected to the ceiling heating coil 44 of the oven heating unit 28. In the second changeover switch 268b, one contact terminal 270b is connected to the heating coil 38 of the right IH heating unit 26, and the other contact terminal 272b is connected to the bottom heating coil 46 of the oven heating unit 28. The movable contact 274a of the first changeover switch 268a is connected to an AC power supply (for example, commercial power supply) 282 via the first inverter 276a, and the movable contact 274b of the second changeover switch 268b is connected to the second inverter 276b. To the AC power supply 282. The first and second inverters 276a and 276b are connected to the control unit 296.

  In the first changeover switch 268a, the movable contact 274a is normally located at the solid line position and connects the heating coil 36 of the left IH heating unit 24 to the first inverter 276a. Similarly, in the second changeover switch 268b, the movable contact 274b is normally located at the solid line position, and connects the heating coil 38 of the right IH heating unit 26 to the second inverter 276b. Further, the movable contacts 274a and 274b of the first changeover switch 268a and the second changeover switch 268b are switched from the solid line position to the dotted line position when the oven heating part on switch in the upper surface operation unit 14 is turned on. It is.

  As shown in FIG. 6, the first inverter 276a and the second inverter 276b have a configuration similar to that of the current resonance type full bridge inverter of the first embodiment described with reference to FIG. More specifically, the first (second) inverter 276a (276b) has two pairs of switching elements 288a and 289a (288b and 289b). As shown in the figure, the first switching element pair 288a (288b) has two switching elements 290a and 292a (290b, 292b) connected in series, and the second switching element pair 289a (289b) is connected in series. Two switching elements 291a and 293a (291b and 293b) are provided. The changeover switch 268a (268b) and the left side IH heating unit 24 (right side IH heating unit) are arranged between the output points of the switching elements 290a and 292a (290b and 292b) and between the output points of the switching elements 291a and 293a (291b and 293b). The heating coil 36 (38) of the unit 26), the ceiling heating coil 44 (bottom heating coil 46) of the oven heating unit 28, and a series resonance circuit including the resonance capacitor 294a (294b) are connected. Also in this embodiment, it is preferable that the heating coils 36 and 44 (38, 46) are designed so that the impedance of the heating coil 36 (38) and the impedance of the heating coil 44 (46) are substantially equal.

  According to the cooking device 1 configured as described above, when the on / off switch 50 of the left IH heating unit 24 of the upper surface operation unit 14 is turned on, the output (alternating current) of the AC power source 282 is output from the DC power source unit 280. After being converted to direct current, the switching elements 290a, 293a and 292a, 291a of the first inverter 276a are alternately turned on / off based on the output from the control unit 296, and the direct current is converted again into high frequency alternating current, A high frequency current is applied to the heating coil 36 of the left IH heating unit 24. Further, when the on / off switch 52 of the right IH heating unit 26 of the upper surface operation unit 14 is turned on, the output (AC) of the AC power supply 282 is converted into DC, and then the second based on the output from the control unit 296. The switching elements 290b, 293b and 292b, 291b of the inverter 276b of the inverter 276b are turned on / off to convert the direct current into high frequency alternating current, and a high frequency current is applied to the heating coil 38 of the right IH heating unit 26.

  The frequency of the switch drive signal output from the control unit 296 to the first inverter 276a is equal to the frequency of the switch drive signal output to the second inverter 276b. For this reason, for example, when the left IH heating unit 24 and the right IH heating unit 28 are driven at different frequencies, an abnormal noise (beat) is generated with the frequency difference between them, as described above, the second embodiment. Then, since the drive frequencies of the left and right IH heating units 24 and 26 are the same, such abnormal noise does not occur.

  Next, when the on / off switch 54 of the oven heating unit 28 in the upper surface operation unit 14 is set to the on state, the changeover switches 268a and 268b are switched from the solid line position to the dotted line position. At the same time, the left and right IH heating units 24 and 26 are disconnected from the inverters 276a and 276b. As a result, a high-frequency current is applied to the heating coils 44 and 46 of the oven heating unit 28, eddy currents are generated in the ceiling wall 40 and the bottom wall 42 of the heating chamber 30, and the Joule heat causes the ceiling wall 40 and the bottom wall 42 to The whole is heated uniformly.

  In the above description, when the oven heating unit 28 is driven, the upper and lower heating coils 44 and 46 are driven at the same time. For example, the upper surface operation unit 14 has an upper surface heating switch for driving only the upper heating coil 44, a lower part. A lower surface heating switch that drives only the heating coil 46 and a double-sided heating switch that drives the two heating coils 44 and 46 are provided. When these upper surface heating switch and lower surface heating switch are turned on, the corresponding changeover switch 268a, Only 268b may be switched from the solid line position to the dotted line position, and only the upper or lower surface of the heating target may be heated. It should be noted that switching between top surface heating, bottom surface heating, and double-sided heating can be configured to be switched with a single switch (for example, a cycle switch).

  Thus, according to the heating cooker 1 which concerns on Embodiment 2, the effect similar to the effect demonstrated in Embodiment 1 is acquired. Moreover, according to the form which driven the upper heating coil 44 and the lower heating coil 46 of the oven heating part 28 separately, fine electric power control and temperature control of a heating chamber are possible according to the cooking content.

Embodiment 3 FIG.
The heating cooker 1 which concerns on Embodiment 3 is demonstrated. In the third embodiment, any one of the three IH heating units is provided with a plurality of heating coils, and the power supply unit corresponding to the plurality of heating coils is shared with the power supply unit of the oven heating unit. is there.

  In the heating cooker 1 according to the third embodiment, the central IH heating unit 22 includes a plurality of heating coils. FIG. 7 shows an embodiment in which the central IH heating unit 22 is provided with two heating coils arranged concentrically, an outer heating coil 334a and an inner heating coil 334b. In this case, the power supply unit 366 has two switching means—a first changeover switch 368a and a second changeover switch 368b−. In the first changeover switch 368a, one contact terminal 370a is connected to the outer heating coil 334a, and the other contact terminal 372a is connected to the ceiling heating coil 44 of the oven heating unit 28. In the second changeover switch 368b, one contact terminal 370b is connected to the inner heating coil 334b, and the other contact terminal 372b is connected to the bottom heating coil 46 of the oven heating unit 28. The movable contact 374a of the first changeover switch 368a is connected to an AC power supply (for example, commercial power supply) 382 via the first inverter 376a, and the movable contact 374b of the second changeover switch 368b is connected to the second inverter 376b. Is connected to an AC power source 382. The first and second inverters 376 a and 376 b are connected to the control unit 396.

  In the first changeover switch 368a, the movable contact 374a is normally located at the solid line position and connects the outer heating coil 334a of the central IH heating unit 22 to the first inverter 376a. Similarly, in the second changeover switch 368b, the movable contact 374b is normally located at the solid line position, and connects the inner heating coil 334b of the central IH heating unit 22 to the second inverter 376b. Further, the movable contacts 374a and 374b of the first changeover switch 368a and the second changeover switch 368b are dotted lines from the solid line position when an ON switch (not shown) for the oven heating unit in the upper surface operation unit 14 is turned on. It switches to the position.

  The upper surface operation unit 14 drives the two heating coils 334a and 334b simultaneously in three modes, that is, an outer heating mode in which only the outer heating coil 334a is driven, an inner heating mode in which only the inner heating coil 334b is driven. A mode selection switch for switching between the overall heating modes is provided.

  Although not shown, the configurations of the first and second inverters 376a and 376b are substantially the same current resonance type full-bridge inverter as that described with reference to FIG.

  According to the cooking device 1 configured as described above, when the outside heating mode is selected by the mode selection switch of the upper surface operation unit 14, the output (AC) of the AC power supply 382 is converted into DC by the DC power supply unit. Thereafter, a high-frequency current is applied to the outer heating coil 334a based on the output from the control unit 396. When the inner heating mode is selected by the upper surface operation unit 14 mode selection switch, the output of the AC power supply 382 (AC) is converted into DC by the DC power supply unit, and then the outer heating is performed based on the output from the control unit 396. A high frequency current is applied to the coil 334b. Further, when the overall heating mode is selected by the mode selection switch, a high frequency current is applied to the outer and inner heating coils 334 a and 334 b based on the output from the control unit 396.

  The frequency of the switch drive signal output from the control unit 396 to the first inverter 376a is equal to the frequency of the switch drive signal output to the second inverter 376b. Therefore, even when the outer and inner heating coils 334a and 334b are driven simultaneously, for example, there is no substantial difference between the frequencies, so that no abnormal noise is generated.

  Next, when the on / off switch 54 of the oven heating unit 28 in the upper surface operation unit 14 is set to the on state, the changeover switches 368a and 368b are switched from the solid line position to the dotted line position. As a result, a high-frequency current is applied to the heating coils 44 and 46 of the oven heating unit 28, eddy currents are generated in the ceiling wall 40 and the bottom wall 42 of the heating chamber 30, and the Joule heat causes the ceiling wall 40 and the bottom wall 42 to The whole is heated uniformly.

  The upper heating coil 44 and the lower heating coil 46 of the oven heating unit 28 may be driven and controlled separately. In this case, for example, an upper surface heating switch that drives only the upper heating coil 44, a lower surface heating switch that drives only the lower heating coil 46, and a double-sided heating switch that drives the two heating coils 44, 46 are provided on the upper surface operation unit 14. When the upper surface heating switch and the lower surface heating switch are turned on, only the corresponding changeover switches 368a and 368b may be switched from the solid line position to the dotted line position to heat only the upper or lower surface to be heated. . Note that switching between top surface heating, bottom surface heating, and double-sided heating can be configured to be switchable with a single switch (eg, a cycle switch).

  In Embodiment 3 mentioned above, you may comprise an outer side heating coil, an inner side heating coil, or both with a some coil part (divided coil). FIG. 8 shows a form in which the outer heating coil 334a is composed of four divided coils 334a (1) to 334a (4). In the case of this form, the four divided coils 334a (1) to 334a (4) are connected in parallel to the contact terminal 370a. The combined impedance of the four divided coils 334a (1) to 334a (4) is designed to be equal to the impedance of the inner heating coil 334b. Instead of the outer heating coil or in addition to the outer heating coil, the inner heating coil 334b may be constituted by a plurality of divided coils. Further, at least one of the heating coils 44 or 46 of the oven heating unit 28 may be formed by a plurality of divided coils. In addition, in the form of FIG. 8, although the outer side heating coil is comprised by four division coils, the number should just be two or more. A plurality of coils may be connected in series.

  In the above description, the central IH heating unit 22 is provided with a plurality of heating coils, and the inverter corresponding to the heating coils is shared with the oven heating unit. However, the left IH heating unit or the right IH heating unit has a plurality of heating coils. And an inverter corresponding to the plurality of heating coils may be shared with the oven heating unit.

  Thus, according to the heating cooker 1 which concerns on Embodiment 3, the effect similar to the effect demonstrated in Embodiment 1 and 2 is acquired. In particular, since the inverter corresponding to the plurality of heating coils provided in one IH heating unit is shared with the oven heating unit, the heating temperatures of the IH heating unit and the oven heating unit can be set finely according to the cooking contents.

Embodiment 4 FIG.
The cooking device 1 according to the fourth embodiment shares one switching element pair (shared switching element pair) of the first inverter with one switching element pair of the second inverter. More specifically, referring to FIG. 9, the first inverter 476a has two pairs of switching elements 488a and 488c. The switching element pair 488a has two switching elements 490a and 492a connected in series, and the switching element pair (common) 488c has two switching elements 491c and 493c connected in series. Between the output points of the switching elements 490a and 492a and between the output points of the switching elements 491c and 493c, the changeover switch 468a, the heating coil 36 of the left IH heating unit 24, the ceiling heating coil 44 of the oven heating unit 28, A series resonance circuit including a resonance capacitor 494a is connected. It is preferable to design the impedance of the heating coil 36 and the impedance of the heating coil 44 equal.

  The second inverter 476b has two pairs of switching elements 488b and 488c, and the latter switching element pair (common) 488c also serves as the switching element pair of the first inverter 476a. The switching element pair 488b has two switching elements 490b and 492b connected in series. As described above, the switching element pair 488c includes the two switching elements 491c and 493c connected in series. Between the output points of the switching elements 490b and 492b and between the output points of the switching elements 491c and 493c, the resonance switch 468b, the heating coil 38 of the right IH heating unit 26, the bottom heating coil 46 of the oven heating unit 28, and the resonance A series resonant circuit including a capacitor 494b is connected. It is preferable to design the impedance of the heating coil 38 and the impedance of the heating coil 46 equal.

  According to the heating cooker 1 configured as described above, when the right and left IH heating units 24 and 26 are driven simultaneously, the movable contacts 274a and 274b of the changeover switches 468a and 468b are set to the solid line positions shown in the drawing, Based on the signal output from the control unit 496, on and off of the switching element 491c (or 493c) as a reference, 490a, 492a, 490b, and 492b are arbitrarily controlled on and off at the same frequency, and a high frequency current is applied. To do.

  When only the left or right IH heating unit 24 (26) is driven, the movable contact 474a (474b) of the changeover switch 468a (468b) is set to the solid line position shown in the drawing. At this time, the movable contact 474b (474a) may be in either the solid line position or the dotted line position. In this state, based on the signal output from the control unit 496, the switching elements 490a, 493c (490b, 493c) are simultaneously turned on or off, the switching elements 492a, 491c (492b, 491c) are simultaneously turned off or on, A high frequency current is applied to the heating coil 36 (38).

  When the upper and lower heating coils 44 and 46 of the oven heating unit 28 are driven, the changeover switches 468a and 468b are both set to the dotted line positions. In this state, based on the signal output from the control unit 496, the 490a, 492a, 490b, and 492b are arbitrarily controlled to be turned on and off at the same frequency with the switching element 491c (or 493c) on and off as a reference. Apply high-frequency current.

  When only one heating coil 44 (46) of the oven heating unit 28 is driven, the movable contact 474a of the changeover switch 468a is set to the dotted line position. At this time, the movable contact 474b may be in either a solid line position or a dotted line position. In this state, based on a signal output from the control unit 496, the switching elements 490a and 493c (or 490b and 493c) are simultaneously turned on or off, and the switching elements 492a and 491c (or 492b and 491c) are simultaneously turned off or on. Then, a high frequency current is applied to the heating coil 44 (46).

  The left or right IH heating unit 24 (26) and the upper or lower heating coil 44 (46) of the oven heating unit 28 may be driven simultaneously. For example, when driving the heating coil 36 (38) of the left (right) IH heating unit 24 (26) and the upper heating coil 44 (lower heating coil 46) of the oven heating unit 28, the movable contact 474a of the changeover switch 468a is a solid line. The movable contact 474b of the changeover switch 468b is set to the dotted line position. In this state, the control unit 496 turns on or off the switching elements 490a and 493c (or 490b and 493c) at the same time, turns off or turns on the switching elements 492a and 491c (or 492b and 491c) at the same time, and heats the heating coil 36 (38). ) And the heating coil 44 (46).

  In FIG. 9, the first inverter 476 a selectively drives the heating coil 36 of the left IH heating unit 24 and the upper heating coil 44 of the oven heating unit 28, and the second inverter 476 b is connected to the right IH heating unit 26. Although the heating coil 38 and the upper heating coil 46 of the oven heating unit 28 are selectively driven, by combining the fourth embodiment with the third embodiment, the first inverter 476a can be connected to an arbitrary IH heating unit. The outer heating coil and the upper heating coil 44 of the oven heating unit 28 are selectively driven, and the second inverter 476b selectively drives the inner heating coil of the IH heating unit and the upper heating coil 46 of the oven heating unit 28. You may make it do.

Embodiment 5 FIG.
In the first to fourth embodiments, one resonance capacitor is used for the series resonance circuit of each inverter, but a resonance capacitor may be provided corresponding to each heating coil. Specifically, with reference to FIG. 10, in the heating cooker 1 of the fifth embodiment, the inverter 576 includes two resonant capacitors 594 and 595. One resonant capacitor (first resonant capacitor) 594 is connected between the contact terminal 570 and the output points of the switching elements 591 a and 593 a together with the heating coil 34. The other resonance capacitor 595 (second resonance capacitor) is connected between the contact terminal 572 and the output points of the switching elements 591a and 593a together with the heating coil 44.

  According to the heating cooker 1 configured as described above, even if there is a difference between the impedance of the heating coil 34 and the impedance of the heating coil 44, the difference is compensated by the characteristics of the resonance capacitor. The resonance frequency of the series resonance circuit including the capacitor 594 and the resonance frequency of the series resonance circuit including the heating coil 44 and the resonance capacitor 595 can be made equal.

  Therefore, according to the fifth embodiment, the resonance frequency of each series resonance circuit can be made equal regardless of the state of the changeover switch, so that the control becomes easy.

  In the above description, the case where the heating coils 34 and 44 are selectively driven by the changeover switch is shown, but the combination of these two heating coils is arbitrary. Further, as in the embodiment, it is particularly preferable to equalize the resonance frequency of the series resonance circuit including the heating coil 34 and the resonance capacitor 594 and the series resonance circuit including the heating coil 44 and the resonance capacitor 595. Even if the resonance frequencies of the series resonance circuits are not equal, it is possible to selectively connect either the former series resonance circuit or the latter series resonance circuit to the inverter 576 by the changeover switch.

Embodiment 6 FIG.
The cooking device 1 according to Embodiment 6 will be described with reference to FIGS. 11 and 12. As shown in the figure, in the heating cooker 1 of the present embodiment, heating coils are arranged on the left and right sides of the heating chamber 610, and induction heating members are arranged in the heating chamber, and induction in the heating chamber is performed by the heating coils. The heating member is heated, and the food or the like is heated by the heat of the induction heating member.

  Specifically, in the heating cooker 1 according to the sixth embodiment, openings 614 and 616 extending horizontally from the near side to the far side are formed above and below the left and right side walls 612 constituting the heating chamber 610. The heat insulating members 618 and 620 are fitted in the openings 614 and 616, respectively. As shown in the drawing, the heat insulating members 618 and 620 are formed with grooves 622 and 624 extending from the near side to the far side by bending the center in the vertical direction outward in a “U” shape. Heating coils 626 are disposed outside the left and right side walls 612, respectively. In each heating coil 626, a part of the coil bundle portion is disposed behind the upper heat insulating member 618 (upper groove portion 622), and another coil bundle portion is disposed behind the lower heat insulating member 620 (lower groove portion 624). . Then, magnetic bodies 628 and 630 having a “U” cross section are disposed so as to surround the coil bundle portion located behind the heat insulating members 618 and 620 and the groove portions 622 and 624 of the heat insulating members 618 and 620. Inside the heating chamber 610, endless heater members (heated members) 632 and 634 made of metal having excellent heat conductivity are arranged, and a part of the heater members 632 and 634 is formed in the upper and lower groove portions 622. , 624.

  The magnetic bodies 628 and 630 are preferably composed of a ferrite core. In addition, the heating coil 626 is formed by winding a so-called litz wire in which a copper wire having a diameter of 0.3 mm is covered with a resin or the like into a plurality of (for example, 19) stranded wires in a substantially rectangular shape (for example, 25 times) Formed by winding).

  The heat insulating member 618 has a two-layer structure of a heat insulating material layer such as glass wool or ceramic wool and a ceramic layer.

  Furthermore, the side wall of the heating chamber 610 may be made of ceramics or may be made of metal such as iron or stainless steel.

  In the heating chamber 610, a grill hole 636 is disposed between the upper and lower heater members 632 and 634, and a tray 637 is disposed under the lower heater member 634.

  According to the cooking device 1 configured as described above, when a high frequency current of 20 to 100 kHz is supplied to the heating coil 626 from a power supply circuit (not shown), a high frequency magnetic flux is generated around the heating coil 626. At this time, the high-frequency magnetic flux generated from the coil portion surrounded by the magnetic bodies 628 and 630 is between the U-shaped magnetic bodies 628 and 630 and the distal end portions (inner end portions) of the U-shaped magnetic bodies 628 and 630. A magnetic circuit passing through the heater members 632 and 634 positioned is formed. Therefore, every time the current flowing through the heating coil 626 reverses in the forward and reverse directions, the direction of the magnetic flux passing through the heater members 632 and 634 changes, and an induction current is generated in the endless heater members 632 and 634, so that the heater members 632 and 632 634 is heated uniformly. Thereby, the to-be-heated object accommodated in the heating chamber 610 is heated uniformly. For example, when 2 kW is supplied from the power supply circuit to each heating coil 626, the heater members 632 and 634 reach about 800 ° C. or more, and the object to be heated can be directly heated by radiant infrared rays.

  The heater members 632 and 634 heat the surrounding air. And the air inside the heating chamber 610 becomes a uniform high temperature by convection and indirectly heats the object to be heated. In this way, the object to be heated accommodated in the oven heating unit is heated and cooked by the radiant heat from the heater members 632 and 634 and high-temperature air. Fat generated from the object to be heated by heating is received by the tray 637.

  Thus, according to Embodiment 6, the heater member in the heating chamber can be pulled out along the groove.

  In addition, although the specific electric circuit which applies a high frequency to a heating coil is not shown about Embodiment 6, the several embodiment mentioned above can be utilized suitably.

  In the sixth embodiment, the upper and lower two heater members are arranged inside the heating chamber, but only one heater member may be provided.

Embodiment 7 FIG.
In general, wide band gap semiconductors are known to have high voltage resistance, high allowable current density resistance, high heat resistance, and low power loss. On the other hand, since the oven heating unit heats food and the like at a high temperature, the temperature around the oven heating unit is very high. Therefore, the heating cooker according to the seventh embodiment is configured such that the switching element of the power supply unit in the plurality of embodiments described above is a wide band gap semiconductor element made of silicon carbide, a gallium nitride material, or diamond. is there. Thereby, it becomes possible to arrange an inverter circuit near the high temperature grill heating section, in particular, below the intake port or the exhaust port shown in FIG. In addition, the power loss and the amount of heat generated in the switching element are reduced, and the heat radiation fin and cooling fan for cooling the switching element are reduced in size, weight, cost, and high temperature reliability. An effect can be obtained.

  As mentioned above, although several embodiment of this invention was described separately, these several embodiment can be combined unless there is a problem in particular. For example, in the second to sixth embodiments, the inner side and the left and right side walls of the oven heating chamber are made of a metal magnetic material, and heating coils are arranged behind them to selectively drive the heating coils. You may make it heat the side wall to do.

1, 2, 3 Heating cooker 10 Case (cooker body)
12 Top plate 14 Upper surface operation unit 16 Ventilation unit 18 Intake port 20 Exhaust port 22 Central IH heating unit 24 Left IH heating unit 26 Right IH heating unit 28 Oven heating unit 30 Heating chamber (heating chamber)
32 Door 34, 36, 38 (IH heating unit) heating coil 40 Oven heating unit ceiling wall 42 Oven heating unit bottom wall 44, 46 Oven heating unit heating coils 48, 50, 52 IH heating unit on / off switch (upper surface operation unit) )
54 Oven heating section on / off switch (top operation section)
56 Display unit 58 Left front operation unit 60 Right front operation unit 62, 64 IH heating unit on / off switch (front operation unit)
66,166 Power supply unit (power supply circuit)
68 IH / Oven switch 70, 72 Contact terminal 74 Movable contact 76 Inverter 78 Switch switching control unit 80 DC power supply unit 82 AC power source 84 Rectifier circuit 86 Smoothing capacitor 88 Switching element pair 90, 92 Switching element 94 Resonance capacitor 96 Control unit 98 Oven heating cabinet back side wall 100 Oven heating cabinet left and right side walls

Claims (16)

A housing,
A first heating coil disposed on an upper surface of the housing;
A heating chamber having a heated portion made of a metal magnetic material at least in part;
A second heating coil disposed in the vicinity of the heated portion;
A power supply that outputs a high-frequency current;
A heating cooker comprising switching means for selectively connecting either the first heating coil or the second heating coil to the power supply unit. The heated portion is at least one wall constituting the heating chamber,
The cooking device according to claim 1, wherein a second heating coil is disposed in the vicinity of the wall. The wall is a ceiling wall and a bottom wall of the heating cabinet, left and right side walls, all or any one of the back walls,
A second heating coil is disposed in the vicinity of the ceiling wall and the bottom wall, the left and right side walls, or all or one of the back walls,
The cooking device according to claim 2, wherein the second heating coils are connected in series, parallel, or series-parallel to each other. The power supply unit includes a direct current power source and an inverter that converts direct current output from the direct current power source into alternating current,
The cooking device according to any one of claims 1 to 3, wherein the inverter is a half-bridge inverter or a full-bridge inverter.   The cooking device according to claim 4, wherein the inverter is a current resonance type half bridge inverter or a current resonance type full bridge inverter. A housing,
At least two first heating coils disposed on an upper surface of the housing;
A heating chamber having a heated portion made of a metal magnetic material at least in part;
At least two second heating coils disposed in the vicinity of the heated portion;
A power supply that outputs a high-frequency current;
A heating cooker comprising switching means for selectively connecting at least one of the two first heating coils or at least one of the two second heating coils to the power supply unit.   The cooking device according to claim 6, wherein at least one of the first heating coil or the second heating coil is configured by a plurality of divided coils. The power supply unit includes a direct current power source, and first and second inverters that convert direct current output from the direct current power source into alternating current,
Each of the first and second inverters has two pairs of switching elements in which two switching elements are connected in series, and the two switching element pairs are connected in parallel to the DC power supply. It consists of first and second full-bridge inverters,
The cooking device according to claim 6 or 7, wherein one switching element pair of the first full-bridge inverter and one switching element pair of the second full-bridge inverter are shared. .   The said power supply part outputs the high frequency of the same frequency to the said 1st heating coil and said 2nd heating coil selectively connected to the said power supply part, Any of Claim 6-8 characterized by the above-mentioned. The cooking device according to claim 1.   The cooking device according to any one of claims 6 to 9, wherein the first and second inverters are current resonance type full bridge inverters.   The heating according to any one of claims 1 to 10, wherein the first heating coil and the second heating coil selectively connected to the power supply unit have the same impedance. Cooking device. The power supply unit includes a first resonance capacitor and a second resonance capacitor connected in series with the first heating coil and the second heating coil that are selectively connected to the power supply unit, respectively.
The first heating coil and the first resonant capacitor connected in series form a first series resonant circuit;
The second heating coil and the second resonant capacitor connected in series form a second series resonant circuit;
12. The switch according to claim 1, wherein the switching unit selectively connects one of the first series resonance circuit and the second series resonance circuit to the power supply unit. The heating cooker according to item. The heated parts are arranged above and below the heating chamber,
The said 2nd heating coil is arrange | positioned so that the magnetic flux formed with the said 2nd heating coil may pass at least one part of the said to-be-heated part, The Claim 1-12 of Claim 12 characterized by the above-mentioned. The heating cooker of any one of Claims.   The cooking device according to claim 13, wherein the heated portion is formed of an endless member.   The cooking device according to any one of claims 1 to 14, wherein the power supply unit includes a switching element using a wide band gap semiconductor element.   The cooking device according to claim 15, wherein the wide band gap semiconductor element is made of any one of silicon carbide, a gallium nitride-based material, and diamond.

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