JP2004290659A - Rice cooker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive rice cooker which can cook tasty rice by promoting the grueling of the rice without making the rice dry in the upper layer thereof. <P>SOLUTION: The rice cooker is provided with a pot induction heating coil 4 for induction heating a pot 2 made of a magnetic material, a pot opening part induction heating coil 13 which induction heats a heating plate 12 made of the magnetic material covering the opening part of the pot 2, a steam generation part which evaporates the water in a water tank 6 made of the magnetic material with a water tank induction heating coil 7 to generate the steam, a steam path 8 which has one end thereof connected to the steam generation part communicating therewith while the other end thereof is opened to the pot, a first inverter circuit for supplying the high-frequency currents to the pot induction heating coil 4, a second inverter circuit for supplying the high-frequency currents to the pot opening part induction heating coil and/or the water tank induction heating coil according to the rice cooking process and a control part. The control part drives the first and second inverter circuits so as not to energize both simultaneously. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a rice cooker that uses steam having a boiling point higher than that of water to improve rice cooking performance.

  In a general household rice cooker, a main heating means disposed at the bottom of the pan and heating the rice and water in the pan is a main heating means. In addition to the pan heating means, to heat the rice pan uniformly during heating and to evaporate excess water on the rice surface in the final step of rice cooking, There is known a rice cooker that energizes and heats a heating means (heater) provided in a rice cooker.

However, since the heating by the heating means in the lid is performed through the space above the rice and water in the pot, the heating is auxiliary. Therefore, the heating amount of rice in the upper layer in the pot was insufficient, and rice and water in the pot could not be heated uniformly.
Furthermore, in the rice cooking, the water is almost lost and the fluidity of the rice is lost. In the steaming step, which is the final step of the rice cooking, the heating up to that point is continued to complete the gelatinization of the rice starch. It is indispensable to cook rice, but in this process, if heating is continued, rice near the bottom of the pot will be scorched, and heating is often weakened.

  Means to prevent insufficient gelatinization due to reduced heating and to improve rice cooking performance include heating the rice from above the pot opening with an induction heating coil that is a high heat source inside the lid. (For example, see Patent Documents 1 and 2).

  FIG. 6 shows a configuration of a rice cooker described in Patent Document 1. In FIG. 6, reference numeral 101 denotes a main body case to which a bottom plate 103 having a support leg 102 is fixed on the lower surface. Reference numeral 104 denotes a protection frame made of heat-resistant plastics, and a flange 105 provided on an upper peripheral portion is fixed to an upper surface of the main body case 101. 106 is a bottom surface heating induction coil mounted on the lower bottom of the protection frame 104, 107 is a side surface heating induction coil installed on the lower bottom of the protection frame 104, and has a magnetic metal layer housed in the protection frame 104. The pot 108 is heated by the bottom surface heating induction coil 106, and the contents of rice and water in the pot 108 are cooked. Reference numeral 109 denotes a temperature sensor mounted in a through hole provided at the center of the bottom surface of the protection frame 104. Reference numeral 110 denotes a lid having a knob 111, which is removably mounted on the upper end flange 105 of the protection frame 104. In addition, an inner cover 112 made of heat-resistant plastics is fixed via a heat insulating material 113. Reference numeral 114 denotes an inner lid detachably mounted on the inner cover 112 by means of pins 120. The peripheral edge of the inner lid is placed on the flange of the pot 108 to cover the pot 108. Reference numeral 115 denotes a main body side upper induction coil installed on the inner surface of the flange 105 of the protection frame 104, which is connected to a power supply unit (not shown) in the main body case 101.

  Reference numeral 116 denotes a lid-side induction coil that is energized by the main-body-side upper induction coil 115 and is mounted on a portion of the lid 110 facing the main-body-side induction coil 115. The current excited by the lid-side induction coil 116 flows through the induction coil 119, and the magnetic flux of the induction coil 119 heats the heating plate 117 formed of a magnetic metal plate by induction heating. Can be done.

  The basic configuration of Patent Literature 2 is the same as that of Patent Literature 1, and the details are omitted here.

Japanese Patent No. 2988050 JP-A-6-62956

  However, in the rice cooker of the above-mentioned conventional configuration, since the rice in the upper layer in the pot is directly heated by the heat radiation of the induction heating coil, in the steaming step, the water of the rice is evaporated and dried. The phenomenon was occurring. Therefore, if the rice cooked in the pot is heated from the top of the pot with the lid-side induction heating coil to a temperature at which sufficient cooking performance can be ensured, the upper layer of the pot will dry and conversely lose its taste. No, the taste was not perfect throughout the pot.

  Furthermore, although the amount of cooked rice and the amount of heating must be increased, as the amount of cooked rice increases, the rice in the upper layer approaches the lid-side induction heating coil and becomes easier to dry. Had to be weakened.

  The first problem can be solved by providing a steam generator and a steam path from the steam generator to the pot, and providing a rice cooker that supplies steam into the pot. By configuring the steam generator with a water tank made of a magnetic material and a water tank induction heating coil that induces and overheats the water tank, the water inside the water tank can be quickly moved as compared with the case of heating by a conductive heating means such as a cord heater. Water can be boiled. This makes it possible to quickly supply high-temperature steam to the upper part of the pot at an appropriate timing in the rice cooking process.

  Further, since steam having a temperature higher than the boiling point of water under atmospheric pressure (100 ° C.) is supplied to the rice from above the opening of the pot, the rice is not dried, and since the steam temperature is 100 ° C. or higher, the steam Promotes the gelatinization of rice without liquefying and adhering to the rice grain surface. The taste of rice can be completely over the whole pot. Furthermore, even when the amount of cooked rice is large, there is no problem that the rice in the upper layer approaches the lid-side induction heating coil and dries. Therefore, the optimum heating amount can be set regardless of the amount of cooked rice.

However, in the case of the above configuration, the second and third problems newly arise.
When the water tank heating means is constituted by an induction heating coil, the rice cooker has at least three induction heating coils as means for heating the pot, the heating plate and the water tank. However, when an inverter circuit for supplying a high-frequency current is attached to each induction heating coil, a second problem that an inexpensive and compact rice cooker cannot be realized has arisen.

  A second problem is that induction heating is performed by supplying a high-frequency current to the heating plate and the induction heating coil of the water tank by one inverter circuit, switching switches connected in series to the respective induction heating coils, and supplying current. This can be solved by selecting a coil.

  In the steaming step, which is the final step of rice cooking, continuing the heating without interruption is a condition for promoting gelatinization and finishing sweet and delicious rice. However, when the steam is generated in the steam generating section while the temperature of the heating plate provided in the pan opening is kept low, when the steam passes through the pan opening, the steam temperature decreases and the temperature in the pan is low. Steam is supplied. Therefore, the temperature of the rice will be lowered, and in the steaming step, the continuation of the heating will be interrupted, preventing the promotion of gelatinization and causing a third problem that delicious rice cannot be cooked. . Furthermore, dew condensation occurs on the heating plate, and dew condensation water stays on the heating plate, rots, and may be mixed into the pot, causing a problem of unsanitation.

  The present invention also solves the third problem described above. Without drying the rice in the upper layer, high-temperature steam is cooked in the pot and supplied immediately after the cooking is completed, thereby promoting gelatinization and improving the taste. It is an object of the present invention to provide an inexpensive rice cooker capable of cooking rice.

  In order to solve the above problems, the present invention has the following configurations. The invention described in claim 1 is a magnetic pot, a pot induction heating coil for induction heating the pot, a magnetic heating plate covering an opening of the pot, and induction heating the heating plate. A pot opening induction heating coil, a water tank made of a magnetic material for filling water, and a water tank induction heating coil for induction heating the water tank, wherein water in the water tank is supplied by the water tank induction heating coil. A steam generator for evaporating to generate steam, a steam path having one end connected to the steam generator and the other end open to the pan, and a first inverter for supplying a high-frequency current to the pan induction heating coil A second inverter circuit that supplies a high-frequency current to one or both of the pan opening induction heating coil and the water tank induction heating coil, and a control unit, wherein the control unit includes 1 inverter times And the second inverter circuit are driven so that they are not energized at the same time, and in accordance with the rice cooking process, the second inverter circuit causes either the pan opening induction heating coil or the water tank induction heating coil to operate. A rice cooker characterized by energizing one or both.

  Thereby, high-temperature steam can be supplied into the pot during steaming, and delicious rice can be cooked without drying the upper rice. Since the pot opening induction heating coil and the water tank induction heating coil are energized by the common second inverter circuit, an inexpensive rice cooker can be realized.

The invention according to claim 2 is characterized in that the water tank induction heating coil is energized to heat the water in the water tank before starting the step of raising the temperature in the pot to about 100 ° C. Item 2. A rice cooker according to item 1.
Before the cooking process of raising the temperature in the pot to about 100 ° C. (also before supplying high-temperature steam into the pot in the steaming process), the water tank induction heating coil is energized to discharge water in the water tank. Preheat. This makes it possible to quickly generate high-temperature steam in the steaming step, and to raise the temperature of the rice without lowering the temperature of the rice once. be able to.

  Preferably, the water tank induction heating coil is energized in the latter half of the pre-cooking step (immediately before the cooking step) to pre-heat the water in the water tank. Since the water in the water tank is not heated for an unnecessarily long time, there is no waste in power consumption and the time until the steaming process is short, so after heating the water in the water tank and before starting steaming, Water temperature does not drop so much. In general, a large amount of electric power is supplied to the pot induction heating coil during the cooking process, so that there is little room for energizing the water tank induction heating coil. Further, the time of the cooking process varies depending on the amount of rice to be cooked. When a very small amount of rice is cooked, the water in the water tank may not be sufficiently heated even when the water tank induction heating coil is energized during the cooking process. By energizing the water tank induction heating coil in the latter half of the pre-cooking step (immediately before the cooking step) and pre-heating the water in the water tank, the water in the water tank can be heated to a high temperature without waste.

  The invention according to claim 3 further comprises a pan temperature detecting means for detecting the temperature of the pan, wherein the control unit detects the temperature in the pan before starting the step of raising the temperature in the pan to about 100 ° C. Having a step of maintaining a state substantially maintained at a predetermined temperature, wherein in the step, when the pan temperature detected by the pan temperature detecting means is higher than a predetermined temperature, only the water tank induction heating coil is energized. The rice cooker according to claim 2, which is a rice cooker.

  When the pan temperature detected by the pan temperature detecting means is higher than a predetermined temperature, only the water tank induction heating coil is energized, and when the pan temperature is lower than the predetermined temperature, the pan induction heating coil is energized to cook rice before cooking. And a rice cooker that performs optimal steaming by preheating the water in the water tank in advance. For example, by energizing only the pot induction heating coil when the pot temperature is lower than the predetermined temperature, the rice cooker does not change its peak power consumption in the pre-cooking process as compared to a rice cooker without a water tank induction heating coil. To achieve.

  The invention according to claim 4 further comprises a pan temperature detecting unit for detecting the temperature of the pan, or a heating plate temperature detecting unit for detecting the temperature of the heating plate, and the control unit is configured to detect the temperature of the heating plate. After detecting that the heating plate temperature detected by the means is a predetermined temperature, or after detecting that the pan temperature detected by the pan temperature detecting means is a predetermined temperature, energize the water tank induction heating coil, The rice cooker according to claim 1, wherein steam is supplied to the pot from the steam path.

  In the present invention, in the steaming step, steam is introduced into the pot while the upper portion of the pot is sufficiently hot. Since the steam generated in the steam generating section is heated by the heating plate heated to 100 ° C. or more, the temperature of the steam quickly rises to 100 ° C. or more, and raises the temperature of the rice without lowering the rice temperature once. be able to. Therefore, gelatinization of starch is promoted, and delicious rice can be cooked.

  The invention according to claim 5 is a state in which the water tank induction heating coil is stopped until the first temperature, which is the temperature of the heating plate or the temperature of another portion of the upper surface of the pan, reaches a predetermined temperature. Energizing the pot opening induction heating coil, after the first temperature reaches a predetermined temperature, energizing the water tank induction heating coil while maintaining the energization state of the pan opening induction heating coil; The rice cooker according to claim 1, characterized in that:

  First, the pot opening induction heating coil is energized to make the upper part of the pan sufficiently hot, and in this state, the water tank induction heating coil is energized to generate steam. According to the present invention, steam can be introduced into the pot after the upper portion of the pot has reliably become hot. Since the steam generated in the steam generating section is heated by the heating plate heated to 100 ° C. or more, the temperature of the steam quickly rises to 100 ° C. or more, and raises the temperature of the rice without lowering the rice temperature once. be able to. Therefore, gelatinization of starch is promoted, and delicious rice can be cooked.

  The state in which the energized state of the pan opening induction heating coil is maintained means a state in which the energized state is substantially maintained. It is not limited to a state where the pot opening induction heating coil does not stop at all (the same applies to other claims). For example, in a rice cooker that distributes an energizing time (an energizing distribution time in the embodiment) to each induction heating coil within a predetermined period in units of a predetermined period (the energizing cycle time in the embodiment), , And the time during which the pot opening induction heating coil is stopped and another time when the pot opening induction heating coil is energized are included. This is because the energized state is substantially maintained also in the latter state.

  The invention according to claim 6 further comprises a heating plate temperature detecting means for detecting a temperature of the heating plate, wherein the control section raises the temperature in the pan to about 100 ° C., If the temperature is equal to or higher than a predetermined temperature, then the output of the pot opening induction heating coil, lower than the output of the pot opening induction heating coil when the temperature of the heating plate is less than a predetermined temperature, The operation of the rice cooker according to claim 5, wherein the temperature of the heating plate is set to the first temperature.

According to the present invention, it is possible to supply appropriately heated steam to rice in the steaming step by using a heating plate temperature detecting means for preventing an excessive rise at the upper part of a pot provided in a conventional rice cooker. . The present invention realizes an inexpensive rice cooker capable of cooking delicious rice by promoting gelatinization of starch.
The “after” of “the subsequent output of the pot opening induction heating coil” may be immediately after or may be the next step.

The invention according to claim 7 is such that the pot opening induction heating coil and the water tank induction heating coil are energized, and then the water tank induction heating coil is energized while the energization state of the pan opening induction heating coil is maintained. The rice cooker according to any one of claims 1 to 6, wherein the rice cooker stops and ends the steaming.
At the end of steaming, prevent low temperature moisture from entering the pot from the water tank. After the new steam is no longer supplied into the pot, a period is provided for the rice to absorb the high-temperature steam in the pot while only the pot opening induction heating coil is energized. As a result, the gelatinization of the rice is further advanced, and the amount of steam contained in the air in the pot is reduced to some extent when the rice cooking is completed (in a state where the rice has been kept warm). When the state changes from the steamed state to the heat-retained state, the temperature in the pot decreases, and the vapor contained in the air is prevented from dew condensation and adhering to the surface of the rice.

  The invention according to claim 8, wherein a check valve that allows steam to flow only from the steam path to the pot side is provided at a pot-side end of the steam path, according to any one of claims 1 to 7. It is a rice cooker.

  At the time of cooking, there is no possibility that steam or rice generated from the pot enters the steam path and contaminates the steam path. In addition, since the infiltration of moisture into the steam path can be prevented, there is no water retention in the steam path, so that when the steam generated in the steam generating section passes through the steam path, a temperature drop due to the moisture of the steam can be prevented. .

According to a ninth aspect of the present invention, the second inverter circuit includes a series-connected body in which the pan opening induction heating coil and a first switch are connected in series, the water tank induction heating coil and a second switch. A control circuit configured to control the opening and closing of the first switch and the second switch in accordance with a rice cooking process; The rice cooker according to claim 1, wherein one or both of the partial induction heating coil and the water tank induction heating coil are energized.
According to the present invention, an inexpensive rice cooker can be provided with a simple configuration.

According to a tenth aspect of the present invention, the second inverter circuit includes a first contact detection circuit that detects opening and closing of a contact of the first switch, and a second contact detecting circuit that detects opening and closing of a contact of the second switch. And a control unit for controlling the open / close state of the first switch and the second switch based on a detection result of the first and second contact detection circuits in the rice cooking process. Determining whether the switch is normal or not, and stopping the power supply to the first inverter circuit and the second inverter circuit when at least one of the switches has an open / closed state that is abnormal. 9. The rice cooker according to 9.
The rice cooker according to the present invention stops rice cooking when the first switch or the second switch is not operating normally. In the rice cooking step, in the step of energizing both the pot opening induction heating coil and the water tank induction heating coil, the first switch or the second switch causes a contact failure and an excessive current flows to the other switch. Can be prevented. ADVANTAGE OF THE INVENTION According to this invention, the rice cooker excellent in safety which an induction heating coil does not abnormally heat can be provided.

The invention according to claim 11, wherein the second inverter circuit includes a first contact detection circuit that detects opening and closing of a contact of the first switch, and a second contact detection circuit that detects opening and closing of a contact of the second switch. And a control unit for controlling the open / close state of the first switch and the second switch based on a detection result of the first and second contact detection circuits in the rice cooking process. It is determined whether or not the current is normal, and energization is performed so that the amount of electricity to the pot opening portion induction heating coil and the water tank induction heating coil does not exceed the amount of electricity according to the rice cooking process. Item 10. A rice cooker according to item 9.
The rice cooker according to the present invention includes a step of energizing both the pot opening induction heating coil and the water tank induction heating coil even when the first switch or the second switch is not operating normally. The switch or the second switch controls the amount of power supply so that contact failure does not occur and an excessive current does not flow to the other switch, and rice cooking is performed to the end. ADVANTAGE OF THE INVENTION According to this invention, the rice cooker excellent in safety which an induction heating coil does not abnormally heat can be provided.

In a twelfth aspect of the present invention, the second inverter circuit includes a first contact detection circuit that detects opening and closing of a contact of the first switch, and a second contact that detects opening and closing of a contact of the second switch. And a second contact detection circuit, wherein the control unit determines whether the open / close state of the first switch and the second switch is normal based on the detection results of the first and second contact detection circuits. Determining whether the open / close state of at least one of the switches is abnormal, stopping the power supply to the second inverter circuit, and supplying power to the first inverter circuit to continue the rice cooking process. The rice cooker according to claim 9, wherein
The rice cooker according to the present invention stops the power supply to the pot opening induction heating coil and the water tank induction heating coil even when the first switch or the second switch is not operating normally, and the pot induction heating coil And then cook rice until the end. ADVANTAGE OF THE INVENTION According to this invention, the rice cooker excellent in safety which an induction heating coil does not abnormally heat can be provided.
In the rice cooker having the third inverter circuit in addition to the first and second inverter circuits, when the first switch or the second switch is not operating normally, the energization to the third inverter circuit is continued. Alternatively, the energization may be stopped.

The invention according to claim 13 further comprises a display unit for displaying a detection result of the first detection circuit and / or the second contact detection circuit. A rice cooker according to the claim.
ADVANTAGE OF THE INVENTION According to this invention, the rice cooker excellent in safety which can make a user recognize the failure of a rice cooker can be provided.

  The rice cooker of the present invention supplies high-temperature steam into the pot after cooking, so that it is possible to promote the gelatinization of starch and to cook delicious rice without drying the upper rice. Having. Since the pot opening induction heating coil and the water tank induction heating coil are energized by the common second inverter circuit, an inexpensive rice cooker can be realized.

  Since the rice cooker of the present invention supplies high-temperature steam into the pot immediately after the completion of cooking, it is possible to cook gelatinized rice by promoting gelatinization of starch without drying the rice in the upper layer. . Since the pot opening induction heating coil and the water tank induction heating coil are energized by the common second inverter circuit, there is an advantageous effect that an inexpensive rice cooker can be realized.

  DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments that specifically show the best mode for carrying out the present invention will be described below with reference to the drawings.

<< Embodiment 1 >>
First Embodiment A rice cooker according to a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a sectional view of a rice cooker according to Embodiment 1 of the present invention. In FIG. 1, reference numeral 1 denotes a main body of a rice cooker, in which a detachable magnetic pot 2 is provided. A cover 3 that covers the upper surface of the main body 1 is installed to be openable and closable.

  The main body 1 has a pot induction heating coil 4 for induction heating the pot 2, a pot temperature detecting means 5 for detecting the temperature of the pot 2, and a water tank induction heating coil 7. The main body 1 includes a removable water tank 6 made of a magnetic material. The water tank 6 and the water tank induction heating coil 7 constitute a steam generating means 38. The steam generating means 38 and a part of the upper surface of the pan 2 are connected by a steam path 8 provided in the lid 3. The opening on the upper surface of the pot 2 in the steam path 8 is referred to as a steam hole 9.

  The lid 3 further includes a heating plate 12 made of a magnetic material, a pot opening induction heating coil 13, and a heating plate temperature detecting means 14 for detecting the temperature of the heating plate 12. The heating plate temperature detecting means 14 is provided in contact with the heating plate 12. A check valve 15 made of silicone rubber that allows steam to pass only from the steam path 8 to the pot side is provided in the steam hole 9 at the tip of the steam path 8 on the pot side.

  Hereinafter, when the pan induction heating coil 4, the pan opening induction heating coil 13, and the water tank induction heating coil 7 are not distinguished, they are referred to as "induction heating coils". The pot induction heating coil 4 has a larger number of turns, a larger linearity of the coil, and the largest heating output as compared with the other two induction heating coils.

  FIG. 2 is a circuit diagram of the rice cooker according to Embodiment 1 of the present invention. The diode bridge 252, the choke coil 253, and the smoothing capacitor 254 input the commercial AC power supply 250 via the power switch 251, and perform full-wave rectification on the commercial AC power supply. The choke coil 253 prevents the AC component of the inverter from leaking to the commercial AC power supply 250 as noise.

  211 is a first inverter circuit. The first inverter circuit 211 includes the pot induction heating coil 4, the resonance capacitor 231, and the first switching element 221. When the first switching element 221 is turned on / off, the first inverter circuit 211 generates a resonance current between the pan induction heating coil 4 and the resonance capacitor 231 to heat the pan 2.

  212 is a second inverter circuit. The second inverter circuit 212 includes the pot opening induction heating coil 13, the water tank induction heating coil 7, the resonance capacitor 232, the first switch 261 and the second switch 262. In the second inverter circuit 212, the pot opening induction heating coil 13 and the first switch 261 are connected in series, the water tank induction heating coil 7 and the second switch 262 are connected in series, and these series circuits are connected. Connected in parallel. When the second switching element 222 is turned on / off, the second inverter circuit 212 includes one or both of the pot opening induction heating coil 13 and the water tank induction heating coil 7 or both of the induction heating coil and the resonance capacitor. 232 and a resonance current. When the first switch 261 is ON, the heating plate 12 is induction heated by the pot opening induction heating coil 13. When the second switch 262 is ON, the water tank 6 is heated by the water tank induction heating coil 7.

  Reference numeral 201 denotes a control unit. The control section 201 includes a control circuit 202, a first switching element driving section 203, a second switching element driving section 204, a first switch driving section 205, and a second switch driving section 206. The first switching element driving unit 203 and the second switching element driving unit 204 receive a signal from the control circuit 202 and drive the first switching element 221 and the second switching element 222 on / off. The first switch driver 205 and the second switch driver 206 receive a signal from the control circuit 202 and open and close the first switch 261 and the second switch 262.

  The rice cooker according to the first embodiment of the present invention has three induction heating coils as means for heating pot 2, heating plate 12, and water tank 6. When an inverter circuit for energizing each induction heating coil is provided one by one, the size of the rice cooker main body 1 increases, and the number of components and the manufacturing process of the rice cooker increase. In the rice cooker according to the first embodiment of the present invention, the supply of the high-frequency current to the induction heating coil for heating the heating plate 12 and the water tank 6 is performed by one inverter circuit (the second inverter circuit 212). Can be reduced, and an inexpensive rice cooker has been realized.

  The control unit 201 sets an energization cycle time with an interval of 16 seconds, and divides one energization cycle time into an energization distribution time to each induction heating coil and a rest time in which energization is not performed. The control unit 201 switches the current distribution time during the repetition of the current cycle time to cook rice. The microprocessor incorporated in the control circuit 202 determines the distribution time of the power distribution to each induction heating coil according to the signals from the heating plate temperature detecting means 14 and the pan temperature detecting means 5 according to the rice cooking process.

  In Embodiment 1, the power consumption of the pot induction heating coil 4 is 1400 W, and the current consumption is 14 A. The power consumption of the pot opening induction heating coil 13 is 300 W, and the current consumption is 3 A. The power consumption of the water tank induction heating coil 7 is 300 W, and the current consumption is 3 A. In general, the rated current of a household breaker is 15 A. Therefore, when energizing the pot induction heating coil 4, the control unit 201 always stops the pot opening induction heating coil 13 and the water tank induction heating coil 7 without fail, and Control is performed so that the total current consumption does not exceed 15A. During one energization cycle time, the first inverter circuit 211 and the second inverter circuit 212 are not driven at the same time but always driven at different timings. Time does not overlap.). Even if the pot opening induction heating coil 13 and the water tank induction heating coil 7 are simultaneously energized, the current consumption (6 A) of the whole rice cooker does not exceed 15 A. Therefore, the control unit 201 performs the first step in the rice cooking process. The switch 261 and the second switch 262 may be turned on at the same time, and both may be energized simultaneously.

  In each energization cycle time, energization distribution times of the pan induction heating coil 4, the pan opening induction heating coil 13, and the water tank induction heating coil 7 are defined as T1, T2, and T3, respectively. When the second inverter circuit 212 is driven and only one of the first switch 216 and the second switch 262 is ON, the entire energization time T within one energization cycle time (T = T1 + T2 ( T3 = 0) or T = T1 + T3 (T2 = 0)) is set to 16 seconds or less, and the current distribution time of each induction heating coil is set. When the second inverter circuit 212 is driven and both the first switch 216 and the second switch 262 are ON, T2 and T3 are equal, and the total energization time T (T = T1 + T2, T3 = The current distribution time of each induction heating coil is determined so that T2) is 16 seconds or less. When the total energization time is less than 16 seconds, the remaining time in one energization cycle time is a pause time in which energization to all the heating coils is stopped.

The operation of the rice cooker according to Embodiment 1 of the present invention will be described according to a rice cooking process. FIG. 3 is a diagram illustrating a rice cooking process of the rice cooker according to the first embodiment of the present invention.
The rice to be cooked and water corresponding to the amount of the rice are put into the pot 2 and the main body 1 is housed in a predetermined state. Further, when a predetermined amount of water is put into the water tank 6 provided in the main body 1 and the power switch 251 for starting rice cooking is turned on, the following rice cooking process is performed.

  The rice cooking process is largely divided into pre-cooking, cooking and steaming. FIG. 3 shows the distribution time of the current of each induction heating coil, the process time, the pot temperature (TE1) detected by the pot temperature detecting means 5 and the heating plate temperature (TE2) detected by the heating plate temperature detecting means 14 in each step. Show.

The pre-cooking process is roughly divided into pre-cook 1, pre-cook 2, and pre-cook 3.
In one pre-cooking step, the power distribution time of the pan induction heating coil 4 is set to a maximum (16 seconds) until the temperature of the pan 2 reaches a temperature (60 ° C.) suitable for water absorption of rice. Heat rice and water inside. The pot opening induction heating coil 13 and the water tank induction heating coil 7 are stopped. When it is detected that the pot temperature TE1 has reached 60 ° C., one pre-cooking step is ended.

  In the two pre-cooking steps, energization of the pan induction heating coil 4 is controlled so that the pan temperature is maintained at 60 ° C. When the pan temperature TE1 is higher than 60 ° C., the energization of the pan induction heating coil 4 is stopped. When the pan temperature TE1 is equal to or lower than 60 ° C., the power distribution time T1 of the pan induction heating coil 4 is set to 8 seconds, and the pan 2 is heated. The pot opening induction heating coil 13 and the water tank induction heating coil 7 are stopped. When the sum of the process times of the pre-cooking 1 and the pre-cooking 2 reaches a predetermined time (about 15 minutes), the pre-cooking 2 is ended, and the process proceeds to the pre-cooking 3 step.

  Also in the three pre-cooking steps, energization to each induction heating coil is controlled so that the pot temperature is maintained at 60 ° C. When the pan temperature TE1 is equal to or lower than 60 ° C., the power distribution time T1 of the pan induction heating coil 4 is set to 8 seconds, and the pan 2 is heated. At this time, the pot opening induction heating coil 13 and the water tank induction heating coil 7 are stopped. When the pot temperature TE1 is higher than 60 ° C., power is supplied to the water tank induction heating coil 7 with the power distribution time T3 of 15 seconds. Thereby, the water in the water tank can be heated in advance before generating high-temperature steam in the steaming step. At this time, the pot induction heating coil 4 and the water tank induction heating coil 7 are stopped. When the process time of the pre-cooking 3 reaches a predetermined time (about 5 minutes), the pre-cooking 3 step is completed, and the process shifts to the cooking step.

The cooking process is largely divided into determination of the amount of cooked rice and maintenance of boiling.
In the rice cooking amount determination step, similarly to the pre-cooking one step, the power distribution time of the pan induction heating coil 4 is set to the maximum (16 seconds), and the temperature of the heating plate temperature detecting means 14 is determined by the steam temperature at which the water in the pan 2 is boiled. The power supply to the pot induction heating coil 4 is continued until the temperature reaches about 90 ° C. At this time, the amount of cooked rice is determined using the correlation between the temperature rise rate of the heating plate 12 (heating plate temperature TE2) and the amounts of rice and water inside the pan 2. The pot opening induction heating coil 13 and the water tank induction heating coil 7 are stopped.

  In the boiling maintaining step, the power distribution time between the pot induction heating coil 4 and the pot opening induction heating coil 13 is set to T1 = 8 seconds and T2 = 7 seconds, respectively, and power is supplied to raise the temperature of the heating plate 12. . When the bottom of the pan 2 is depleted and the temperature TE1 of the pan 2 reaches a predetermined temperature (136 ° C.) exceeding 100 ° C., the heating by the pan induction heating coil 4 is stopped, and the cooking process is completed. Move to the steaming process. In the boiling maintaining step, the heating plate temperature detecting means 14 detects the temperature of the heating plate 12. If the temperature of the heating plate 12 becomes equal to or higher than 130 ° C., the control unit 201 sets the distribution time of the power supply to the pot opening induction heating coil 13 in the boiling maintaining process to be shorter than T2 = 7 seconds. In the boiling maintaining step, the water tank induction heating coil 7 is stopped.

  The steam hole 9 is provided with a check valve 15 made of silicone rubber which allows steam to pass only from the steam path 8 to the pot side at the tip of the steam path 8 on the pot side. Therefore, the steam and the rice cake generated in the pot 2 during the cooking process do not enter the steam path 8 and the steam path is not contaminated.

The steaming process is roughly divided into a pause 1, an additional cook 1, a pause 2, an additional cook 2, and a pause 3.
In the pause 1 step, only the pot opening induction heating coil 13 is energized for a predetermined time (about 1 minute) with the energization distribution time T2 set to 10 seconds. Thereby, the temperature of the heating plate 12 rises. The pan induction heating coil 4 and the water tank induction heating coil 7 are stopped. When the heating plate temperature detection means 14 detects that the heating plate 12 has reached a predetermined temperature (130 ° C.), the heating plate opening induction heating coil 13 and the water tank induction heating coil 7 are connected to each other by energizing distribution time T2 = T3. = 10 seconds. The pan induction heating coil 4 is stopped. The water in the heated water tank 6 boils, and the generated steam is supplied into the pot 2 through the steam path 8. The water in the water tank 6 is heated in advance in the three pre-cooking steps and is quickly heated by the water tank induction heating coil 7 as compared with a normal sheath heater or the like, so that it boils quickly. Since the temperature of the heating plate 12 has already been increased to 130 ° C., the supplied steam becomes high-temperature steam whose temperature has increased to around 130 ° C. This can prevent the vapor from liquefying and sticking to the surface of the rice in the upper layer of the pot. By the above rice cooking process, the temperature of the rice in the pot can be raised by the high-temperature steam without lowering the temperature in the pot, so that the gelatinization of the starch in the rice in the pot is promoted and the rice becomes delicious. .

  In one additional cooking step, the pan 2 is heated while supplying high-temperature steam into the pan for about 3 minutes. The energization distribution time T1 of the pot induction heating coil 4 is set to 4 seconds, and the energization distribution time of the opening induction heating coil 13 and the water tank induction heating coil 7 is set to T2 = T3 = 7 seconds.

In the pause 2 step, high-temperature steam is supplied into the pan for about 2 minutes, and the heating of the pan 2 is stopped. The current is distributed between the opening induction heating coil 13 and the water tank induction heating coil 7 by setting T2 = T3 = 7 seconds. The pan induction heating coil 4 is stopped.
The additional cooking process performs the same operation as the additional cooking process.
In the reheating 1, pause 2 and reheating 2 processes, the pot opening induction heating coil 13 and the water tank induction heating coil 7 are simultaneously energized, so that high-temperature steam can be continuously supplied to the inside of the pan 2, and rice starch Gelatinization can be promoted.

  In the pause 3 step, only the opening induction heating coil 13 is set to T2 = 2 seconds for about 2 minutes to energize (the pan induction heating coil 4 and the water tank induction heating coil 7 are stopped), and cook rice. finish. Since the heating of the water tank 6 is stopped and the heating plate 12 is heated after the steam generation is completed, excess water on the surface of the rice can be skipped to make the rice more delicious. By stopping (finally) the water tank induction heating coil 7 in the pause 3 step, supply of new steam from the water tank 6 is stopped. By energizing only the opening induction heating coil 13, the steam contained in the air above the pot is absorbed by the rice without the temperature drop from 130 ° C. so much. Thereby, when the rice cooking is completed, excess steam in the air above the pot is not included (when the rice cooking is completed and the temperature in the pot decreases, the excess steam is liquefied and adheres to the surface of the rice). .

  After the rice cooking is completed, the operation is shifted to heat retention, and the power supply to the pot induction heating coil 4 and the pot opening induction heating coil 13 is controlled so that the temperature in the pot approaches 70 ° C. At this time, in order to prevent dew drops on the heating plate 12, the temperature of the heating plate 12 needs to be higher than the temperature in the pot. Therefore, the distribution time T2 of the power distribution to the pot opening induction heating coil 13 is set longer than the distribution time T2 of the power distribution to the pan induction heating coil 4. When the pot temperature TE1 is higher than 70 ° C., the power supply to all the induction heating coils is stopped. When the pan temperature TE1 is 70 ° C. or lower, the power distribution is performed by setting the power distribution time T1 to the pan induction heating coil 4 to 1 second and the power distribution time T2 to the pan opening induction heating coil 13 to 2 seconds. The water tank induction heating coil 7 is stopped.

  In the first embodiment, the water tank is preheated in the three pre-cooking steps. However, the water tank may be heated any time before the high-temperature steam is supplied into the pot 2 in the steaming step. For example, heating may be performed in two pre-cooking steps.

<< Embodiment 2 >>
Second Embodiment A rice cooker according to a second embodiment of the present invention will be described with reference to FIGS. 1 and 3 to 5. The rice cooker according to the second embodiment differs from the rice cooker according to the first embodiment only in the electric circuit diagram. Other configurations are the same as those of the rice cooker according to the first embodiment. The same portions are denoted by the same reference numerals, and description thereof will be omitted.
FIG. 4 is an electric circuit diagram of the rice cooker according to Embodiment 2 of the present invention. The electric circuit of the rice cooker according to the second embodiment includes the control unit 201 of the electric circuit (FIG. 2) of the rice cooker of the first embodiment as the control unit 401, and the second inverter circuit 212 as the second inverter circuit 412. Each of them is replaced and a display element 465 is added. The control unit 401 is obtained by replacing the control circuit 202 of the control unit 201 of the first embodiment with a control circuit 402. The second inverter circuit 412 is obtained by adding a first contact detection circuit 463 and a second contact detection circuit 464 to the second inverter circuit 212 of the first embodiment.
The display element 465 is means for displaying the operation of the rice cooker. In the first embodiment, display element 465 is an LED (Light Emitting Diode).

The first contact detection circuit 463 detects opening / closing (ON / OFF) of the first switch 261. FIG. 5 is a circuit diagram of first contact detection circuit 463 of the rice cooker according to Embodiment 2 of the present invention. The first contact detection circuit 463 includes resistors 501, 502, and 505, a transistor 504, a capacitor 506, and a diode 503. The resistor 501 and the resistor 502 are connected in series between the contact and the ground when the first switch 261 is open. A diode 503 is connected in parallel with the resistor 502. The anode of the diode 503 is connected to the ground, and the cathode is connected to the connection point between the resistors 501 and 502. The base of the transistor 504 is connected to the connection point between the resistors 501 and 502, and the emitter is grounded. A resistor 505 is connected between the power supply (for example, +5 V) of the control circuit and the collector of the transistor 504. The capacitor 506 has one end connected to the collector of the transistor 504 and the other end grounded. The voltage of the collector of the transistor 504 is input to the control circuit 402 as an output signal of the first contact detection circuit 463. When the first switch 261 is closed (switched to the solid line side), no signal is input to the base of the transistor 504. The output signal of the first contact detection circuit 463 is at a high level. When the first switch 261 is in an open state (when switched to the broken line side), a high-frequency signal is input to the base of the transistor 504. When the high-frequency signal has a positive value, a current flows to the base of the transistor 504, and the collector potential is grounded. When the high frequency signal has a negative value, a current flows through the diode 503. When a high-frequency signal is input to the base of the transistor 504, the capacitor 506 holds the collector potential at a low level. The output signal of the first contact detection circuit 463 is at a low level.
The second contact detection circuit 464 detects opening / closing (ON / OFF) of the second switch 262. The second detection circuit 464 has the same configuration as the first detection circuit 463 (FIG. 5) and performs the same operation.

  In the control unit 401, the first switching element driving unit 203 and the second switching element driving unit 204 receive a signal from the control circuit 402 and turn on / off the first switching element 221 and the second switching element 222. Drive. The first switch driving unit 205 and the second switch driving unit 206 receive a signal from the control circuit 402 and open and close the first switch 261 and the second switch 262.

  The control unit 401 sets an energization cycle time with an interval of 16 seconds as in the case of the control unit 201 of the first embodiment, and sets one energization cycle time to the distribution time and the energization to each induction heating coil. Cut to rest time. The control unit 401 switches the current distribution time during the repetition of the current cycle time and cooks rice. The microprocessor incorporated in the control circuit 202 determines the distribution time of the power distribution to each induction heating coil according to the signals from the heating plate temperature detecting means 14 and the pan temperature detecting means 5 according to the rice cooking process.

  The control unit 401 compares the output signal of the first contact detection circuit 463 with the signal input to the first switch driving unit 205, and determines whether the first switch 261 is in a normal open / closed state. . In addition, the output signal of the second contact detection circuit 464 is compared with the signal input to the second switch driver 206 to determine whether the second switch 262 is in a normal open / closed state. The controller 401 blinks the display element 465 when detecting that either the first switch 261 or the second switch 262 is not operating normally in the rice cooking or warming process. Further, the first switching element 221 and the second switching element 222 are turned off, and power is supplied to all the induction heating coils (the pan induction heating coil 4, the pan opening induction heating coil 13, and the water tank induction heating coil 7). To stop. That is, cooking is stopped.

  Since the first switch 261 and the second switch 262 pass a large current of 3 A at the maximum, the contact deteriorates with long-term use, and there is no possibility that the contact is welded in the open state or the closed state. I can't say. If one switch is welded in the open state, an excessive current may flow through the other switch and the induction heating coil connected in series with the switch. For example, in a normal reheating one step (FIG. 3), both the first switch 261 and the second switch 262 are closed, and a current of 3 A is applied to the pot opening induction heating coil 13 and the water tank induction heating coil 7, respectively. Flows. However, when the first switch 261 is welded in the open state, a current of 6 A, twice the normal current, flows through the second switch 262 and the water tank induction heating coil 7. Therefore, the temperature of the water tank 6 and the water tank induction heating coil 7 becomes high, which is dangerous. In the three normal rest steps, only the first switch 261 is closed, and a current of 3 A flows through the water tank induction heating coil 7. However, when the second switch 262 is welded in the closed state, the current of less than 3 A flows through the pot opening induction heating coil 261 and the surface of the rice becomes sticky. The rice cooker according to Embodiment 2 stops cooking rice when the first switch 261 or the second switch 262 is not operating normally. ADVANTAGE OF THE INVENTION According to this invention, the rice cooker excellent in safety which can notify a user of a failure without abnormal heating of an induction heating coil can be provided.

  When any one of the first switch 261 and the second switch 262 does not operate normally, the amount of electricity supplied to the pot opening induction heating coil 13 and the water tank induction heating coil 7 is a predetermined amount according to the rice cooking process. Electricity may be supplied so as not to exceed the amount of electric current (see FIG. 3), and rice may be cooked to the end. When detecting that one of the first switch 261 and the second switch 262 does not operate normally, the control circuit 402 performs control according to the situation. For example, when the first switch 261 is welded in an open state, if it is in a normal state, a rice cooking process (for example, one additional cooking in FIG. 3) in which both the pot opening induction heating coil 13 and the water tank induction heating coil 7 are energized. In, the control circuit 402 controls so that only the water tank induction heating coil 7 is energized. This can prevent an excessive current from flowing through the second switch 262 and the water tank induction heating coil 7. For example, when the first switch 261 does not operate normally, rice can be cooked although the upper rice is sticky. When the second switch 262 does not operate normally, rice can be cooked at the same level as a conventional rice cooker without a water tank. According to the present invention, even when the first switch 261 or the second switch 262 does not operate normally, rice cooking is performed to the end, the induction heating coil does not abnormally heat, and the user can be notified of a failure, and is excellent in safety. Rice cooker can be provided. If the rice cooker breaks down, even if the taste is inferior, if the rice to be eaten on that day can be cooked, the troubles experienced by the user can be minimized.

  When any of the first switch 261 and the second switch 262 does not operate normally, the power supply to the second inverter circuit 412 (the power supply to the pot opening induction heating coil 13 and the water tank induction heating coil 7) is applied. The current supply may be stopped, and the first inverter circuit 211 (the pot induction heating coil 4) may be supplied with electricity to cook rice to the end. Even if only the pot induction heating coil 4 is used, it is possible to cook rice at the same level as the conventional induction heating rice cooker having the simplest structure. According to the present invention, even when the first switch 261 or the second switch 262 does not operate normally, rice cooking is performed to the end, the induction heating coil does not abnormally heat, and the user can be notified of a failure, and is excellent in safety. Rice cooker can be provided. If the rice cooker breaks down, even if the taste is inferior, if the rice to be eaten on that day can be cooked, the troubles experienced by the user can be minimized.

Note that the display element 465 is not limited to an LED. Any display means such as a liquid crystal display that allows the user to easily recognize the abnormality of the rice cooker may be used.
The circuit configuration of the rice cooker of the present invention is not limited to those shown in FIGS. 2, 4, and 5.
The conditions of the power distribution time, the power cycle time, and the temperature in each of the rice cooking and heat retaining processes are not limited to those shown in FIG.

  The rice cooker of the present invention is useful as a domestic or commercial rice cooker.

Sectional view of rice cookers according to Embodiments 1 and 2 of the present invention Electric circuit diagram of rice cooker according to Embodiment 1 of the present invention The figure which shows the rice cooking process of the rice cooker of Embodiment 1 and Embodiment 2 of this invention. Electric circuit diagram of rice cooker according to Embodiment 2 of the present invention Circuit diagram of first contact detection circuit of rice cooker according to Embodiment 2 of the present invention Sectional view of conventional electric rice cooker

Explanation of reference numerals

DESCRIPTION OF SYMBOLS 1 Main body 2 Pot 3 Lid 4 Pot induction heating coil 5 Pot temperature detecting means 6 Water tank 7 Water tank induction heating coil 8 Steam path 9 Steam hole 12 Heating plate 13 Pot opening induction heating coil 14 Heating plate temperature detecting means 15 Non-return Valve 38 Steam generating means 201, 401 Control unit 202, 402 Control circuit 203 First switching element drive unit 204 Second switching element drive unit 205 First switch drive unit 206 Second switch drive unit 211 First inverter Circuit 212, 412 Second inverter circuit 221 First switching element 222 Second switching element 231 Resonant capacitor 232 Resonant capacitor 250 Commercial AC power supply 251 Power switch 252 Diode bridge 253 Choke coil 254 Smoothing capacitor 261 First switch 2 62 second switch 463 first contact detection circuit 464 second contact detection circuit 465 display element

Claims (13)

A magnetic pot,
A pan induction heating coil for induction heating the pan,
A heating plate made of a magnetic material covering the opening of the pan,
A pot opening induction heating coil for induction heating the heating plate,
A water tank made of a magnetic material for storing water, and a water tank induction heating coil for induction heating the water tank, wherein steam is generated by evaporating water in the water tank by the water tank induction heating coil. Generating part,
A steam path, one end of which is connected to the steam generator and the other end is open to the pan;
A first inverter circuit for supplying a high-frequency current to the pan induction heating coil;
A second inverter circuit for supplying a high-frequency current to one or both of the pot opening induction heating coil and the water tank induction heating coil,
And a control unit,
The control unit drives the first inverter circuit and the second inverter circuit so that they are not energized at the same time, and in accordance with the rice cooking process, the second inverter circuit guides the pot opening part induction. A rice cooker characterized by energizing one or both of a heating coil and the water tank induction heating coil. The rice cooker according to claim 1, wherein the water tank induction heating coil is energized to heat the water in the water tank before starting the step of raising the temperature in the pot to about 100 ° C. Further comprising a pan temperature detecting means for detecting the temperature of the pan,
The control unit has a step of maintaining a state in which the temperature in the pan is maintained at a substantially predetermined temperature before starting the step of raising the temperature in the pan to about 100 ° C., and in the step, the pan temperature detecting unit includes: The rice cooker according to claim 2, wherein when the detected pot temperature is higher than a predetermined temperature, only the water tank induction heating coil is energized. Further comprising a pan temperature detecting means for detecting the temperature of the pan, or a heating plate temperature detecting means for detecting the temperature of the heating plate,
The controller, after detecting that the heating plate temperature detected by the heating plate temperature detection means is a predetermined temperature, or after detecting that the pan temperature detected by the pan temperature detection means is a predetermined temperature, The rice cooker according to claim 1, wherein the water tank induction heating coil is energized to supply steam from the steam path to the pan. The pot opening induction heating coil is energized with the water tank induction heating coil stopped until the temperature of the heating plate or the first temperature of the other part of the upper surface of the pan reaches a predetermined temperature. Then, after the first temperature reaches a predetermined temperature, the water tank induction heating coil is energized while the energization state of the pan opening induction heating coil is maintained. Rice cooker. Further comprising a heating plate temperature detecting means for detecting the temperature of the heating plate,
In the step of raising the temperature in the pot to about 100 ° C., the control unit outputs the output of the pot opening induction heating coil after the temperature of the heating plate reaches a predetermined temperature or higher, and outputs the temperature of the heating plate. Is lower than the output of the pan opening induction heating coil when the temperature is lower than a predetermined temperature, and in the operation according to claim 5, the temperature of the heating plate is set to the first temperature. The rice cooker according to claim 5, wherein Energizing the pot opening induction heating coil and the water tank induction heating coil, and then stopping the water tank induction heating coil while maintaining the energized state of the pan opening induction heating coil, and terminating the steaming. The rice cooker according to any one of claims 1 to 6, characterized in that: The rice cooker according to any one of claims 1 to 7, further comprising a check valve provided at a pot-side end of the steam path to pass steam only from the steam path to the pot. The second inverter circuit includes a series connection body in which the pot opening induction heating coil and a first switch are connected in series, and a series connection body in which the water tank induction heating coil and a second switch are connected in series. And a circuit connected in parallel with
The control unit controls opening and closing of the first switch and the second switch in accordance with a rice cooking process, and energizes one or both of the pot opening induction heating coil and the water tank induction heating coil. The rice cooker according to claim 1, wherein the rice cooker is operated. The second inverter circuit further includes a first contact detection circuit that detects opening and closing of a contact of the first switch, and a second contact detection circuit that detects opening and closing of a contact of the second switch. And
In the rice cooking process, the control unit determines whether or not the open / closed state of the first switch and the second switch is normal based on the detection results of the first and second contact detection circuits. 10. The rice cooker according to claim 9, wherein when the open / close state of the switch is abnormal, the power supply to the first inverter circuit and the second inverter circuit is stopped. The second inverter circuit further includes a first contact detection circuit that detects opening and closing of a contact of the first switch, and a second contact detection circuit that detects opening and closing of a contact of the second switch. And
In the rice cooking process, the control unit determines whether or not the open / closed state of the first switch and the second switch is normal based on the detection results of the first and second contact detection circuits. When the open / close state of the switch is abnormal, the power is supplied to the pot opening induction heating coil and the water tank induction heating coil so that the amount of current does not exceed the amount of current according to the rice cooking process. The rice cooker according to claim 9, wherein The second inverter circuit further includes a first contact detection circuit that detects opening and closing of a contact of the first switch, and a second contact detection circuit that detects opening and closing of a contact of the second switch. And
The control unit determines whether the open / close state of the first switch and the second switch is normal based on the detection results of the first and second contact detection circuits, and determines whether at least one of the switches is open or closed. The rice cooker according to claim 9, wherein when the open / close state is abnormal, the power supply to the second inverter circuit is stopped, and the power supply to the first inverter circuit is continued to continue the rice cooking process. The rice cooker according to any one of claims 10 to 12, further comprising a display unit that displays a detection result of the first detection circuit and / or the second contact detection circuit.

Images