JP2004313404A - Electric rice cooker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric rice cooker which enables the obtaining of the output as high as possible while preventing the mutual interference of magnetic fields between a plurality of work coils when the plurality of work coils are provided. <P>SOLUTION: In the electromagnetic induction heating type electric rice cooker with more than three sets of the plurality of work coils, a work coil drive control means which drives and controls drive the plurality of work coils individually is provided so as to prevent the work coils adjacent to each other from being driven simultaneously out of the plurality of the coils. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a configuration of an electromagnetic induction heating type rice cooker having a plurality of work coils.
[0002]
[Prior art]
Conventionally, in this type of electric rice cooker, when driving the plurality of work coils, for example, the first work coil on the bottom part of the rice cooker and the second work coil on the lid part of the rice cooker, the duty ratio is determined to be n. The first and second work coils are turned on at the first timing of the count of T seconds (cycle T is arbitrary) of / T (seconds), and turned off in response to the lapse of n seconds set according to the menu. ON / OFF control pattern is adopted.
[0003]
However, in such a configuration, the first and second two sets of work coils are energized at the same time, and the second work coil is entirely turned on during the ON period n of the first work coil. Will be duplicated. For this reason, the magnetic field between the two work coils interferes with each other, and the beat becomes high. On the other hand, in setting the output of the first and second work coils, the allowable maximum power consumption 1400 (W) from one outlet in a general household is set. ), The output value of each work coil must be appropriately distributed and set, and the output of each work coil cannot be sufficiently increased.
[0004]
Therefore, in order to solve such a problem, for example, there is a configuration in which the plurality of work coils are always operated individually by switching between ON and OFF states so that at least ON timings of the plurality of work coils do not overlap (see, for example, US Pat. See, for example, Patent Document 1.
[0005]
In the case of this configuration, for example, when the work coils are the first and second two sets, the ON and OFF patterns are as shown in FIG. 9, and when the work coils are the first, second and third sets, the work coil shown in FIG. Such an ON / OFF pattern is obtained.
[0006]
With such a configuration, since the ON periods of the first, second, or first, second, and third work coils do not overlap with each other, noise due to the interference of the magnetic field between the work coils can be reliably prevented. At the same time, the output value of each work coil can be increased to the maximum allowable power of 1400 (W).
[0007]
[Patent Document 1]
JP-A-8-196417 (pages 2 to 6, see FIGS. 1 to 6)
[0008]
[Problems to be solved by the invention]
However, as described above, in the configuration in which the operation timings are completely switched so that the ON timings of a plurality of work coils do not overlap each other, the ON / OFF control is performed. When trying to increase the above-described duty ratio: n / T, the heating output (duty ratio: n / T) of the other work coil decreases by that amount, and the heating output between the work coils is balanced. Is difficult.
[0009]
In particular, even if an attempt is made to increase the total heating output obtained by synergizing the heating outputs of the respective work coils, it is impossible to increase the total heating output. This problem becomes more remarkable as the number of work coils increases when the number of work coils is three (FIG. 10) than when the number of work coils is two (FIG. 9).
[0010]
The present invention has been made in order to solve such a problem. In the case where a plurality of work coils are provided as described above, it is possible to prevent interference of magnetic fields between work coils as much as possible. It is an object of the present invention to provide an electric rice cooker capable of obtaining as high an output as possible.
[0011]
[Means for Solving the Problems]
The present invention has the following problem solving means in order to achieve the above object.
[0012]
(1) First Problem Solving Means A first problem solving means of the present invention is an electromagnetic induction heating type electric rice cooker including three or more sets of a plurality of work coils, wherein each of the plurality of work coils is provided. Work coil drive control means for driving control is provided, and the work coil drive control means is configured not to simultaneously drive mutually adjacent work coils among the plurality of work coils.
[0013]
According to such a configuration, at least work coils that are not adjacent to each other can be driven at the same time, and the output is controlled such that the total heating output of the plurality of work coils driven at the same time is within the range of the rated output. This makes it possible to meet the demand for high heating output in the heating process during cooking and the like.
[0014]
On the other hand, the plurality of non-adjacent work coils that are simultaneously driven are spatially separated from each other, so that the magnetic fields generated by the individual work coils are unlikely to interfere with each other, and the interference sound (beats) ) Is less likely to occur.
[0015]
(2) Second Problem Solving Means According to a second problem solving means of the present invention, in the configuration of the first problem solving means, the plurality of work coils respectively heat the same electromagnetic induction heating object by electromagnetic induction heating. It is characterized by that.
[0016]
If the work coils driven at the same time heat electromagnetically different objects to be heated by electromagnetic induction, the objects to be vibrated (vibration characteristics) of the generated magnetic field are different, and interference noise is less likely to be generated.
[0017]
Therefore, what should be particularly considered as a problem in noise reduction is a case where a plurality of work coils each heat the same electromagnetic induction heating object by electromagnetic induction. In this case, the first problem is solved. The configuration of the solving means is particularly effective.
[0018]
(3) Third Problem Solving Means A third problem solving means according to the present invention is the configuration according to the first or second problem solving means, wherein any of the plurality of work coils is one of the following: It is characterized in that different electromagnetic induction heating objects are subjected to electromagnetic induction heating.
[0019]
Of course, if the work coils driven at the same time as described above heat electromagnetically different objects to be heated by electromagnetic induction, the object of vibration (vibration characteristics) of the generated magnetic field differs, and the Although it is difficult to generate noise, it does not mean that no interference sound is generated.
[0020]
Therefore, also in this case, the configuration of the first problem solving means works beneficially.
[0021]
(4) Fourth Problem Solving Means A fourth problem solving means according to the present invention is the configuration according to the third problem solving means, wherein the electromagnetic induction heated object is a rice cooker and a lid provided on an upper part of the rice cooker. Wherein the different electromagnetic induction heated object is a heat sink of the lid.
[0022]
As an example in which any one of the work coils in the plurality of work coils heats a different electromagnetic induction heated object by electromagnetic induction, various cases can be considered. There are two types of objects: a rice cooker and a heat radiating plate of a lid provided above the rice cooker, and a different electromagnetic induction heated object heated by any one of the work coils by electromagnetic induction heating is a heat radiating plate of the lid. The case is considered as a typical example.
[0023]
(5) Fifth problem solving means According to a fifth problem solving means of the present invention, in an electromagnetic induction heating type electric rice cooker comprising three or more sets of a plurality of work coils, each of the plurality of work coils is provided. Work coil drive control means for controlling the drive is provided, and the work coil drive control means does not simultaneously drive the work coils for electromagnetically heating the same electromagnetic induction heating object among the plurality of work coils, but different drive coils. It is characterized in that the work coils for heating the electromagnetic induction heating object by electromagnetic induction are driven simultaneously.
[0024]
According to such a configuration, at least work coils having different electromagnetic induction heating objects can be driven simultaneously, and the total heating output of the plurality of simultaneously driven work coils is within the range of the rated output. By controlling the output in such a manner as described above, it is possible to respond to a high heating output request in a temperature raising step or the like during cooking.
[0025]
In this case, when the work coils driven at the same time are configured to perform electromagnetic induction heating on different objects to be subjected to electromagnetic induction heating, the vibration target (vibration characteristics) of the generated magnetic field is different, Interference sound hardly occurs.
[0026]
(6) Sixth Problem Solving Means According to a sixth problem solving means of the present invention, in the configuration of the first, second, third, fourth, or fifth problem solving means, the work coils that are driven simultaneously are different from each other. Are characterized in that the output magnitudes are different from each other.
[0027]
As described above, when a plurality of work coils are driven simultaneously, the total heating output of each of the work coils must be set within a predetermined rated output.
[0028]
On the other hand, when the work coil is employed as the heating means, the electromagnetic induction heating means does not function effectively unless there is at least an output of a predetermined magnitude.
[0029]
Therefore, in order to adjust the total heating output to within the rated output as described above, the outputs of the plurality of work coils are made to differ in magnitude, and the output of the work coil having a small output is first set to a predetermined required magnitude. Then, the output is adjusted by reducing the output of the work coil having a large output.
[0030]
【The invention's effect】
As a result, according to the electric rice cooker of the present invention, it is possible to drive the work coils adjacent to each other among the plurality of work coils or sharing the object to be heated so as not to overlap each other. By reducing the interference of the magnetic field and driving the work coils that are not adjacent to each other or different from each other, the total output of the work coils in each case corresponds to the high heating output. As a result, an effective high heating output can be obtained.
[0031]
BEST MODE FOR CARRYING OUT THE INVENTION
(Embodiment 1)
1 to 7 show a configuration of an electromagnetic induction heating type electric rice cooker according to Embodiment 1 of the present invention having a plurality of work coils.
[0032]
(Configuration of rice cooker body and lid unit)
First, FIGS. 1 to 4 show a configuration of a rice cooker main body and a lid unit of the electric rice cooker.
[0033]
The electric rice cooker is basically composed of a rice cooker main body in which the rice cooker is stored and a lid unit covering an upper part of the rice cooker main body, and a bottom of the rice cooker (inner pot) in the rice cooker main body. A first work coil for electromagnetically heating the lower side of the rice cooker, a second work coil for electromagnetically heating the side of the rice cooker to the side of the rice cooker, and a secondary work coil inside the lid unit. As induction heating members, each of the rice cookers (inner pot) is provided with a heat sink made of a magnetic metal material having a high heat dissipation performance, and the heat sink is further provided on the shoulder of the rice cooker body by electromagnetic induction heating. And an electromagnetic induction heating type provided with a third work coil.
[0034]
That is, as shown in FIGS. 1 to 3, the electric rice cooker is entirely made of a magnetic metal material (iron-based metal material) such as a stainless steel material capable of self-heating by an eddy current induced therein as a whole. A rice cooker (inner pot) 1, an inner case (protection frame) 2 made of a synthetic resin formed into a bottomed cylindrical shape so that the rice cooker 1 can be arbitrarily stored and set, and the inner case 2 is held. An opening is formed at the upper part of a rice cooker main body 4 which is a cylindrical outer case 3 which is an outer casing, and which is formed by joining and integrating the outer case 3 and the inner case 2 to form a bottomed cylindrical body having an open top. And a cover unit 5 that can be opened and closed.
[0035]
As shown in FIG. 3, the bottom wall 2a of the inner case 2 has a first work coil L for heating a rice cooker concentrically shunted, for example, at different positions on the inside and outside in the radial direction. ₁ is provided, the work coil L ₁ of said first heating the whole by heating the central surface and the side surface side of the bottom portion 1b of the rice instrument 1 housed in the inner case 2 uniformly, They cook rice efficiently. Further, the side wall 2a of the same inside the casing 2 is adapted to the second work coil L ₂ is provided, the work coil L ₂ of said second, side of the rice apparatus 1 at the time of cooking time and kept The section 1a is heated.
[0036]
The outer case 3 includes, for example, a vertically-covered cylindrical cover member (side plate) 3a formed of a synthetic resin plate, a synthetic resin shoulder member 3b provided at an upper end of the cover member 3a, And a bottom member 3c provided at the bottom of the cover member 3a. An inner hook-like shoulder piece 7 of the shoulder member 3b is engaged with and supported by an upper portion of the shoulder member support piece 2b on the upper end side of the inner case 2 and bent upward on the hook in the outer circumferential direction. and integrated, to their top, the heat radiating plate 10 is a secondary side the electromagnetic induction heating member 3 is the work coil L ₃ is provided a primary electromagnetic induction heating means for electromagnetic induction heating I have.
[0037]
Work coil L ₃ of said third litz wire is made more than once around the outer periphery side from the horizontal direction in the peripheral side of the L-shaped cross section of the coil holder 8 which has an engaging rib 8a standing upright upwardly on the inner peripheral side The upper and both sides are covered by a synthetic resin coil cover 9 having an inverted J-shaped cross section, and the upper end of the inner case 2 and the shoulder member of the outer case 3 are formed. Together with 3b, it forms an opening edge of the rice cooker main body 4.
[0038]
The opening edge of the rice cooker 1 in which the opening 1b is reduced in diameter with respect to the opening edge of the rice cooker main body 4 including the _third work coil L3 in the storage set state. The position is adapted to the positional relationship in which electromagnetic induction heating is possible as shown.
[0039]
On the other hand, the lid unit main body portion, which is a non-magnetic member of the lid unit 5, has an outer cover 5A made of a synthetic resin, which constitutes the outer peripheral surface thereof, and an inner frame portion which is a ridge in the circumferential direction inside the outer cover 5A. An inner space 5C is formed in a hollow heat insulating structure from the synthetic resin inner cover 5B fixedly provided.
[0040]
Below the inner cover 5B of the lid unit main body, a radiator plate 10 made of a magnetic metal material capable of electromagnetic induction heating is detachably provided. At the center of the outer cover 5A and the inner cover 5B constituting the lid unit main body, a pressure adjusting port 11 is formed penetrating in both up and down directions. A large-diameter pressure adjusting unit 12 having a structure is detachably fitted from above. At the lower part of the pressure adjusting port 11, a cylindrical portion 13 for mounting the heat radiating plate 10 is provided, and a relatively small-diameter fitting portion provided at the center of the heat radiating plate 10 in the cylindrical portion 13 is provided. The radiator plate 10 itself is detachably mounted by fitting and locking the cylindrical portions 14 via convex and concave portions provided between them.
[0041]
On the other hand, a base portion of a first packing 15a is fixed to an outer peripheral side fixing portion between the inner frame portion of the outer cover 5A and the inner cover 5B, and the heat sink 10 has an outer peripheral upper surface (sealing portion). 10b) is sealed by the first packing 15a.
[0042]
In the configuration of the lid unit 5, the heat radiating plate 10 has a heat radiating portion 10 a projecting slightly downward corresponding to the diameter of the reduced opening 1 c of the rice cooker 1, and an outer peripheral side of the heat radiating portion 10 a. And a seal portion 10b having an inverted U-shaped cross section which covers the upper end of the opening 1a of the rice cooker 1 via a second packing 15b, and an opening of the rice cooker main body 4 on the outer peripheral side of the seal 10b. It is formed from the electromagnetic induction heating unit 10c facing face through the third work coil L ₃ with a predetermined gap G edges.
[0043]
Then, for example, the third work coil L ₃ is driven by the third work coil driving circuit of FIG. 5 to be described later, correspond to the electromagnetic induction heating section 10c of the heat radiating plate 10 periphery by electromagnetic induction heating thereto Then, heat is generated, and the heat is transmitted to the heat radiating portion 10a via the seal portion 10b, and is radiated from the entire surface of the heat radiating portion 10a to the rice in the rice cooker 1.
[0044]
On the other hand, the outer cover 5A is deeply extends downwardly to the outer edge of the inner frame portion periphery is continuous with the outer peripheral surface of the shoulder member 3b with enlarged outer diameter, the third work coil L ₃ The outer peripheral surface of the portion is reliably covered so that heat generated in the induction heating area is not released to the outside.
[0045]
Above the front part of the rice cooker main body 4, for example, a substantially half-moon-shaped operation panel section 17 as shown in FIG. 1 is provided. The operation panel section 17 includes a liquid crystal display section 19 having a sufficiently large and large display area, a rice cooker switch 17a, a timer reservation switch 17b, a cancel switch 17c, a heat / reheat switch 17d, an off switch 17e, and a menu operation switch 17f. , An hour switch 17g, a minute switch 17h, and other various operation switches (touch key portion of the touch key switch).
[0046]
(Structure of rice cooker body side control circuit part)
Next, FIG. 5 shows a configuration of an electric control circuit portion centering on a microcomputer control unit for controlling rice cooking and heat retention of the rice cooker main body configured as described above.
[0047]
In the figure, reference numeral 32 denotes a microcomputer control unit (CPU) for controlling rice cooking and heat keeping, which includes rice cooking heating control means, heat keeping heating control means, inner pot temperature determining means, inner pot detecting means, buzzer notifying means, and the like. The microcomputer control unit 32 is mainly composed of a microcomputer, and includes, for example, a temperature detection circuit section of the rice cooker 1, first, second, and third work coil drive control circuit sections, a presence / absence detection circuit section of the rice cooker 1, and an oscillation circuit. , A reset circuit section, a heater control circuit section, a buzzer notification section, a power supply circuit section, and the like.
[0048]
First, a temperature detection circuit 43 provided corresponding to the rice cooker temperature detection sensor S of the center sensor section on the bottom wall 1b side of the above rice cooker (inner pot) 1 is provided with, for example, the rice cooker temperature detection sensor S. The temperature detection signals of the bottom wall 3a of the rice cooker 1 are respectively input.
[0049]
Further, the first, second, and third work coil drive control circuit units respectively include, for example, first, second, and third pulse oscillation circuits 41A, 41B, and 41C, first, second, and third synchronization circuits. Trigger circuits 40A, 40B, 40C, first, second, and third IGBT drive circuits 42A, 42B, 42C, first, second, and third IGBTs 37A, 37B, 37C, first, second, and third The feedback circuits 34A, 34B, 34C and the first, second, and third resonance capacitors 38A, 38B, 38C and the like are formed. By controlling the first, second, and third pulse oscillation circuits 41A, 41B, and 41C by the first, second, and third work coil drive control circuits of the microcomputer control unit 32, for example, The wattage of the first, second, and third work coils L ₁ , L ₂ , and L ₃ and the ON duty ratio (for example, n seconds / 16 seconds) at the same wattage are determined according to the rice cooking (or warming) process. By appropriately changing each, the heating temperature and heating pattern of the rice cooker 1 in each step of the rice cooking (or warming) process are appropriately variably controlled in consideration of the amount of the rice (warming), so that uniform water absorption and uneven heating can be obtained. Appropriate heating output control for realizing the cooking and keeping the heat of rice is not performed.
[0050]
In the present embodiment, in these cases, the ON, OFF patterns of the first, second, and third work coils L ₁ , L ₂ , and L ₃ are, for example, as shown in a time chart of FIG. The ON, OFF patterns of the first, second, and third work coils L ₁ , L ₂ , and L ₃ suitable for the required heating amount are appropriately set and corresponded to the respective steps of the rice cooking (heating) step. Like that.
[0051]
The ON / OFF patterns of the first, second, and third work coils L ₁ , L ₂ , and L ₃ are set and controlled, for example, as shown in a flowchart of FIG. 6 described later.
[0052]
Reference numerals 22a to 22h denote the various input switches described above. When the necessary switches are properly operated, the recognition means of the microcomputer control unit 32 recognizes the contents of the user's instruction and recognizes the contents. The desired rice cooking or heat retention heating pattern as described above is set according to the contents, and the rice heating control means or the heat retention heating control means is appropriately operated to perform desired rice cooking or heat retention.
[0053]
Therefore, the user uses the same input switch 22a to 22h to cook or keep rice, timer reservation, reservation time setting, white rice or brown rice, fast-cooking, rice porridge, kamagami or soft or soft, sushi, cooking, etc. If you select and set various types of rice cooking or steaming, such as steaming, normal warming or low-temperature warming, and heat insulating functions, the corresponding function contents will be cooked or steamed via the above-described recognition means of the microcomputer control unit 32, and will be warmed. The setting is automatically input to the heating pattern setting unit, and the corresponding rice cooking, steaming, and heat-retaining heating control is appropriately performed.
[0054]
Further, reference numeral 17 denotes a buzzer notification unit for notifying completion of rice cooking and the like, and reference numeral 21 denotes a liquid crystal display unit. In the case of this embodiment, necessary items such as a desired menu and time are displayed on the liquid crystal display unit 21 in response to the ON operation of the input switches 22a to 22h. (Such as a frame).
[0055]
In FIG. 5, 31 is a power supply circuit, 33 is a zero cross signal circuit, 35 is a rectifier circuit, 36 is a smoothing capacitor, and CL is a choke coil.
[0056]
(First to third work coil output control methods)
Next, FIG. 6 shows a method of controlling the output of each work coil of the electric rice cooker in this embodiment.
[0057]
In the control, firstly in step _{S 1,} the first to third work coil _L 1 ~L ₃ output time (ON time during one period T shown in Figure 7: heating time) is set, respectively ( _{L 1> L 2 = L 3} ).
[0058]
Thereafter in step S _2, first to drive the rice vessel bottom first side work coil L _1. And thereby, the heating control by the output of the _first work coil L1 is executed.
[0059]
In step S _3, the first work coil L ₁ determines whether or not the setting heating time of the main shoulder side third work coil L ₃ nonadjacent has passed, when NO is step S proceed to ₄ to drive the same third work coil L _3.
[0060]
As a result, as shown in the time chart of FIG. 7, spaced lower and upper part of the rice device 1, that the first work coil L ₁ and the third work coil L ₃ that is not adjacent to each other are driven simultaneously (At least within the heating time of the _third work coil L3).
[0061]
On the other hand, when the YES setting the heating time of the third work coil _{L 3} of YES has elapsed, the process proceeds to step _{S 5,} to OFF the third work coil _{L 3.}
[0062]
Then the process proceeds to step S _6, the simultaneous of the first it is judged whether or not the set heating time of the work coil L ₁ has elapsed, the first when NO, the third work coil L _1, L ₃ driving or first driving work only coil L ₁ after the third work coil L ₃ OFF is continued until YES, and whereas becomes to YES, and stops the first driving of the work coil L _1, the following second driving work only coil _{L 2} in step _{S 8} in. Drive state of the second work coil L ₂ is continued in the following step S ₉ to set the heating time of the second work coil L ₂ is determined to have elapsed.
[0063]
As a result, as is apparent from the time chart of FIG. 7, first, in the case of the second work coil L _1, rice unit side wall second work coil L ₂ of the intermediate position with any adjacent L ₂ will always be only the second work coil L ₂ is driven solely.
[0064]
In step S _9, when it has elapsed set heating time of the second work coil L ₂ is is determined, the same second work coil L ₂ is turned OFF at step S ₁₀ that follows.
[0065]
In the next cycle, is repeated again over the same first to third driving control of the work coil _L 1 ~L ₃ (Step _S 1 _{to S 10)} (see FIG. 7), a predetermined time (N × T... N is the number of times of control), the heating control to reach a predetermined target rice cooker temperature in a predetermined process in the rice cooking process is realized.
[0066]
As described above, in this embodiment, as described above, in the electromagnetic induction heating type rice cooker including three or more sets of the work coils L ₁ , L ₂ , and L ₃ adjacent to each other, Work coil drive control means for driving and controlling each of the plurality of work coils L ₁ , L ₂ , L ₃ is provided, and the work coil drive control means is provided among the plurality of work coils L ₁ , L ₂ , L ₃ . the work coil L ₁ and L _2, L ₂ and L ₃ which are adjacent to each other simultaneously are characterized by being configured so as not to drive.
[0067]
With this configuration, the other mutual work coil L ₁ and L ₃ together not adjacent to can be driven simultaneously, the total heat output of the plurality of work coils L _1, L _3, which is driven during of identity is one By controlling the output so as to be within the range of the maximum rated output of the outlet of 1400 (W), it is possible to respond to a high heating output request in a temperature raising step or the like during cooking.
[0068]
On the other hand, the plurality of work coils L ₁ and L _{3 that} are not adjacent to each other and are driven at the same time are spatially largely separated between the lower part and the upper part of the rice cooker 1. _1, the magnetic field generated by the L ₃ is less likely to interfere with each other, interference noise (beat) is less likely to occur.
[0069]
In the above configuration, the plurality of work coils L ₁ and L ₂ are each configured to perform electromagnetic induction heating on the rice cooker 1 that is the same electromagnetic induction heated object.
[0070]
On the other hand, the other hand, in the case of a plurality of work coils L ₁ and L ₃ are driven simultaneously, as in the above rice unit 1 and the heat radiating plate 5, a different the electromagnetic induction heated to electromagnetic induction heating Has become. Therefore, in this case, the object to be vibrated (vibration characteristics) of the generated magnetic field is different, and it is difficult to generate interference sound.
[0071]
Therefore, what should be considered as a problem in noise reduction is the case of L ₁ and L _{2 in which} the plurality of work coils respectively heat the same electromagnetic induction heating object by electromagnetic induction. Is particularly effective in a configuration that does not perform simultaneous driving as described above.
[0072]
From such a viewpoint, in the above configuration, the work coils L ₁ and L ₃ driven at the same time electromagnetically heat different electric induction heating objects such as the rice cooker 1 and the heat sink 5. .
[0073]
Therefore, even when driven at the same time, the object to be vibrated (vibration characteristics) of the generated magnetic field is different, and it is difficult to generate interference sound.
[0074]
Therefore, also in this sense, the above-described configuration is beneficial for reducing noise.
[0075]
In still above structure, the work coil L ₁ and L ₃ in which the driven simultaneously, the magnitude of the output to each other becomes different from (L _{1> L 3).}
[0076]
As described above, when a plurality of work coils L ₁ and L ₃ are driven simultaneously, the total heating output of each of the work coils L ₁ and L ₃ is set within a predetermined rated output 1400 (W). There must be.
[0077]
On the other hand, when each of the work coils L ₁ and L ₃ is employed as the heating means, the work does not function effectively as the electromagnetic induction heating means unless there is at least an output of a predetermined magnitude.
[0078]
Accordingly, the adjustment of the total heating output to within the rated output 1400 (W) as described above is performed by making the outputs of the plurality of work coils L ₁ and L ₃ different in magnitude (L ₁ > L ₃ ), and small sets the output towards the work coil L ₃ first, a predetermined required size, so as to adjust by decreasing towards the large output of the work coil L ₁ of the output thereon.
[0079]
As a result, according to the electric rice cooker of this embodiment, the magnetic field interference is reduced as much as possible by driving the mutually adjacent work coils among the plurality of work coils so as not to overlap each other, On the other hand, by superimposing and driving the work coils which are not adjacent to each other and which are different from each other with the electromagnetic induction heating object, the total output thereof is adapted to the high heating output. Therefore, an effective high heating output can be obtained while reducing noise.
[0080]
(Embodiment 2)
In the case where the work coils that are simultaneously driven as described above heat electromagnetic induction heating objects that are different from each other, the object to be vibrated (vibration characteristics) of the generated magnetic field is different, and interference occurs. Although it is difficult to generate sound, it does not mean that no interference sound is generated.
[0081]
Therefore, even in such a case, it is preferable not to simultaneously drive at least when the work coils are adjacent to each other.
[0082]
(Embodiment 3)
Next, FIG. 8 shows a configuration of an electromagnetic induction heating type rice cooker according to Embodiment 3 of the present invention.
[0083]
In the configuration of the first embodiment, the first, the second, third work coil L _1, L _2, a third body shoulder the work coil L ₃ of the of L _3, the lid unit 5 side radiating it is assumed that corresponds to the electromagnetic induction heated 10c of the plate 10, in this embodiment, arranged in a vertical corresponding to the third work reduced diameter opening 1c of the coil L ₃ rice instrument 1 and were of the structure, yet the U-shaped cross section of the indirect heating member 6 made of a magnetic metal material capable induction heating between the opening 1c and the third work coil L ₃ of rice device 1 in a ring shape The configuration is provided.
[0084]
When employing such a configuration, the third work coil L _3, unlike the first embodiment, both the the electromagnetic induction heated 10c of the indirect heating member 6 and the heat sink 10 It will be heated by electromagnetic induction.
[0085]
Therefore, also in this case, the third work coil L ₃ are also different in the first, second work coil L _1, the electromagnetic induction heating thereof and L ₂ for electromagnetic induction heating of the food unit 1 Will be.
[0086]
As a result, first the work coil L ₁ and the third work coil L _3, it is possible to simultaneously drive as in the second embodiment.
[Brief description of the drawings]
FIG. 1 is a partially cutaway front view showing an entire configuration of a rice cooker main body of an electric rice cooker according to Embodiment 1 of the present invention.
FIG. 2 is an enlarged cross-sectional view of a portion where a second and third work coils are installed on an upper part of the rice cooker main body of the electric rice cooker.
FIG. 3 is an enlarged sectional view of a portion where a first work coil is installed at a lower portion of the rice cooker main body of the electric rice cooker.
FIG. 4 is a skeleton diagram schematically showing a basic configuration of the electric rice cooker.
FIG. 5 is an electric circuit diagram of first, second, and third work coil drive control circuit portions which are main parts of the electric rice cooker.
FIG. 6 is a flowchart showing a basic control operation of first to third work coils during normal rice cooking of the electric rice cooker.
FIG. 7 is a time chart showing ON and OFF patterns of first, second, and third work coils in a rice cooking process of the electric rice cooker.
FIG. 8 is a skeleton diagram showing an outline of a basic configuration of a rice cooker main part of an electric rice cooker according to Embodiment 2 of the present invention.
FIG. 9 is a time chart showing ON and OFF patterns of first and second work coils in a heating step of a conventional electric rice cooker.
FIG. 10 is a time chart showing ON / OFF patterns of first, second, and third work coils in a heating step of a conventional electric rice cooker.
[Explanation of symbols]
1 is a rice cooker, 2 is an inner case, 3 is an outer case, 3a is a cover member, 3b is a shoulder member, 4 is a rice cooker main body, 5 is a lid unit, 10 is a heat sink, 32 is a microcomputer control unit, and 37A is a 1 of IGBT, 37B the second IGBT, the 38A first resonance capacitor, 38B is a second resonance capacitor, 30 is a buzzer, _{L 1} is the first work coil, _{L 2} is the second work coil. L ₃ is a third work coil.

Claims (6)

In an electromagnetic induction heating type electric rice cooker comprising three or more sets of a plurality of work coils, a work coil drive control means for driving and controlling each of the plurality of work coils is provided, and the work coil drive control means comprises: An electric rice cooker characterized in that work coils adjacent to each other among a plurality of work coils are not driven simultaneously. The electric rice cooker according to claim 1, wherein each of the plurality of work coils heats the same electromagnetic induction heating object by electromagnetic induction heating. 2. The electric rice cooker according to claim 1, wherein any one of the plurality of work coils heats a different electromagnetic induction heating object by electromagnetic induction. 4. The electric device according to claim 3, wherein the object to be heated by electromagnetic induction is a rice cooker and a radiator plate of a lid provided above the rice cooker, and the different object to be heated by induction is a radiator plate of the lid. rice cooker. In an electromagnetic induction heating type electric rice cooker comprising three or more sets of a plurality of work coils, a work coil drive control means for driving and controlling each of the plurality of work coils is provided, and the work coil drive control means comprises: The work coils for electromagnetically heating the same electromagnetic induction heating object among a plurality of work coils are not simultaneously driven, but the work coils for electromagnetically heating different electromagnetic induction heating objects are simultaneously driven. An electric rice cooker. The electric rice cooker according to any one of claims 1, 2, 3, 4, and 5, wherein the work coils that are driven simultaneously have different outputs.

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