JP2004236859A - Electric rice cooker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To minimize oscillation sound without reducing the energizing time of the other-side electromagnetic induction heating means even in the case of high output in an electric rice cooker provided with a plurality of electromagnetic induction heating means. <P>SOLUTION: The electric rice cooker provided with: a rice container capable of electromagnetic induction heating; a rice cooker body for housing the rice container; a plurality of the electromagnetic induction heating means positioned on the side of the rice cooker body for electromagnetic induction heating of the housed rice container; and a heating control means for driving and controlling the plurality of the electromagnetic induction heating means with each other at a prescribed ON and OFF timing. As for the mutual ON and OFF patterns of the plurality of the electromagnetic induction heating means, with the finishing timing of the OFF pattern in the ON and OFF patterns of one of the electromagnetic induction heating means as reference, the ON pattern of the other induction heating means is set to make the ON pattern correspond to the OFF pattern as the reference. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a configuration of an electromagnetic induction heating type rice cooker including a plurality of electromagnetic induction heating means such as work coils.
[0002]
[Prior art]
Conventionally, in this type of electric rice cooker, the plurality of electromagnetic induction heating means, for example, the first work coil L on the bottom side of the rice cooker. ₁ And the second work coil L of the rice cooker shoulder (or side) side ₂ In general, as shown in the time chart of FIG. 8, when driving is performed, both are turned on at the first timing of counting 16 seconds (this time is arbitrary) of n / 16 (seconds) for determining the duty ratio, and according to the menu. An ON / OFF control pattern that turns OFF in response to the elapse of n seconds set as described above has been adopted.
[0003]
However, in the case of such a configuration, at the same time, the first and second two sets of work coils L ₁ , L ₂ And the second work coil L ₂ Means that all of the ON periods n of the first work coil L ₁ Is overlapped with the ON period n. Therefore, both work coils L ₁ , L ₂ Resonates and the oscillating sound (beat) increases, while the first and second work coils L ₁ , L ₂ In setting the output of each work coil L in the range of the maximum allowable power consumption 1500 (W) from one outlet in a general household, ₁ , L ₂ Output values must be appropriately distributed and set. ₁ , L ₂ Each output could not be made large enough.
[0004]
Therefore, in order to solve such a problem, for example, a plurality of work coils L as described above are used. ₁ , L ₂ There is a device which is always switched to operate so that at least the ON timing does not overlap (for example, see Patent Document 1).
[0005]
[Patent Document 1]
JP-A-8-196417 (pages 2 to 6, see FIGS. 1 to 6)
[0006]
[Problems to be solved by the invention]
With such a configuration, each work coil L ₁ , L ₂ Since the ON periods of the work coils do not overlap, the oscillation sound can be reduced and ₁ , L ₂ Can be increased up to the maximum allowable power consumption of 1500 (W).
[0007]
However, such a plurality of work coils L ₁ , L ₂ In the configuration in which ON and OFF control is performed by completely switching the ON timings so that the ON timings do not overlap, if an attempt is made to increase the heating output (duty ratio: n / 16) of any one of the work coils, the other work is correspondingly increased. The heating output of the coil (duty ratio: n / 16) decreases, and each work coil L ₁ , L ₂ It is difficult to balance heating output.
[0008]
In particular, each work coil L ₁ , L ₂ However, even if an attempt is made to increase the total heating output, which is a synergistic effect of the above heating outputs, it is impossible to increase the total heating output.
[0009]
The present invention has been made to solve such a problem, and the ON / OFF pattern of the plurality of electromagnetic induction heating means is basically the same as the ON / OFF pattern of any one of the electromagnetic induction heating means. The above-mentioned problem has been solved by setting the ON pattern of the other electromagnetic induction heating means on the basis of the end timing of the OFF pattern in the above and making the ON pattern correspond to the OFF pattern on the basis of the above. It is an object to provide an electric rice cooker.
[0010]
[Means for Solving the Problems]
The present invention has the following problem solving means in order to achieve the above object.
[0011]
(1) First problem solving means
Means for solving the first problem of the present invention are a rice cooker capable of electromagnetic induction heating, a rice cooker main body containing the rice cooker, and electromagnetic induction heating of the stored rice cooker on the rice cooker main body side. An electric rice cooker comprising: a plurality of electromagnetic induction heating means; and a heating control means for drivingly controlling the plurality of electromagnetic induction heating means at predetermined ON and OFF timings. In the ON / OFF pattern of the above, the ON pattern of the other induction heating means is set based on the end timing of the OFF pattern of the ON / OFF pattern of any one of the electromagnetic induction heating means, and the ON pattern is defined as the above reference. It is characterized in that it corresponds to the OFF pattern described above.
[0012]
According to such a configuration, for example, in a normal heating output state having a long control time, by driving a plurality of electromagnetic induction heating means such as a plurality of work coils so as not to overlap each other, oscillation noise due to resonance is reduced as much as possible. On the other hand, in a process requiring high heating output such as a cooking process, it is possible to easily obtain an effective high heating output by driving a plurality of work coils in an overlapping manner only for a necessary period for output setting. It becomes.
[0013]
Moreover, they can be easily realized only by changing the set time of the duty ratio setting timer in the backward calculation direction without changing the heating control pattern which is the basis of each electromagnetic induction heating means.
[0014]
(2) Second problem solving means
According to a second aspect of the present invention, in the configuration of the first aspect, in a normal heating output step, the ON patterns of the plurality of heating units are not overlapped with each other. And
[0015]
As described above, in a process in which the control time is long and a normal heating output is sufficient, such as a boiling maintaining process that does not particularly require a large heating output, the ON timings of the plurality of electromagnetic induction heating units are overlapped. The heating is controlled by the heating output of each of the electromagnetic induction heating means without causing any oscillation sound as much as possible.
[0016]
(3) Third problem solving means
According to a third aspect of the present invention, in the configuration of the first aspect, in the high heating output step, the ON patterns of the plurality of heating units overlap each other for a predetermined period. And
[0017]
According to such a configuration, it is possible to obtain a desired high heating output within the range of the maximum allowable power value in which the heating outputs of the plurality of electromagnetic induction heating means are synergistic.
[0018]
(4) Fourth problem solving means
According to a fourth aspect of the present invention, in the configuration of the first aspect, the high heating output step is a full power heating step such as a heating step, a cooking step, or a reheating step. And
[0019]
In such a temperature raising step after completion of the water absorption heating step, a cooking step or a reheating step after completion of rice cooking, high heating output with full power is generally required.
[0020]
Therefore, in such a process, the required high heating output is realized by effectively synergizing the outputs of the respective electromagnetic induction heating means by overlapping the ON timings of the plurality of electromagnetic induction heating means.
[0021]
(5) Fifth problem solving means
According to a fifth aspect of the present invention, in the configuration of the first, second, third or fourth aspect, the plurality of electromagnetic induction heating means are provided at a bottom portion of the rice cooker main body. And a second work coil on the shoulder of the rice cooker main body for inductively heating the bottom of the rice cooker body and heating the edge of the rice cooker opening and the inner lid radiator plate.
[0022]
Thus, the above-mentioned plurality of electromagnetic induction heating means are provided at the bottom of the rice cooker main body for induction heating the bottom of the rice cooker, and at the shoulder of the rice cooker main body at the edge of the rice cooker opening edge. And a second work coil that heats the inner lid heatsink portion, the two work coils have a positional relationship between the lower part and the upper part of the rice cooker main body, which are hardly influenced by each other, in a large distance. It will be.
[0023]
Therefore, in the same configuration, when they are simultaneously turned on at the time of the high heating output as described above, there is little effect and no large oscillation sound is generated.
[0024]
【The invention's effect】
As a result, according to the electric rice cooker of the present invention, the oscillation sound is reduced as much as possible by driving the electromagnetic induction heating means such as a plurality of work coils so as not to overlap in a normal heating output state having a long control time. On the other hand, in a process requiring a high heating output such as a cooking process, an effective high heating output can be obtained by driving a plurality of work coils in an overlapping manner.
[0025]
Moreover, they can be easily realized only by changing the set time of the duty ratio setting timer without changing the heating control pattern which is the basis of each electromagnetic induction heating means.
[0026]
Further, in the high heating output step such as the above-described full power step, the total control time is shorter than that in the ordinary heating output step such as the boiling maintaining step, and the oscillation sound is less likely to cause a problem.
[0027]
BEST MODE FOR CARRYING OUT THE INVENTION
(Embodiment 1)
1 to 6 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.
[0028]
(Configuration of rice cooker body and lid unit)
First, FIGS. 1 to 3 show a configuration of a rice cooker main body and a lid unit of the electric rice cooker.
[0029]
The electric rice cooker is basically composed of a rice cooker main body in which the rice cooker is stored and a lid unit for 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 electromagnetic induction heating of the rice cooker (inner pot), and a secondary induction heated member inside the lid unit, which has high heat radiation performance into the rice cooker (inner pot), A heat radiation plate made of a metal material is provided, and an electromagnetic induction heating type is further provided with a second work coil on the shoulder of the rice cooker body for electromagnetic induction heating the heat radiation plate. .
[0030]
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.
[0031]
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, and the first work coil L ₁ Is designed to heat the entirety by uniformly heating the central side and the side of the bottom 1b of the rice cooker 1 housed in the inner case 2 so as to efficiently cook rice. As shown in FIG. 2, a heat retaining heater 6 is provided on the outer surface of the inner case 2 near the upper side of the side wall portion 2a, and the heat retaining heater 6 fixes the side surface portion 1a of the rice cooker 1 when keeping the temperature. It is designed to be heated.
[0032]
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 a second primary work coil L for heating the radiating plate 10 serving as a secondary-side electromagnetically-induced heated member by electromagnetic induction heating. ₂ Is provided.
[0033]
The second work coil L ₂ Has a flat ring structure in which a litz wire is wound a plurality of times from the horizontal inner circumferential side to the outer circumferential side of the coil holder 8 having an L-shaped cross section and having an engaging rib 8a rising upward on the inner circumferential side. The upper and both sides are covered by a synthetic resin coil cover 9 having an inverted J-shaped cross section, and are integrated with the upper end of the inner case 2 and the shoulder member 3b of the outer case 3 to form The opening edge of the rice cooker main body 4 is configured.
[0034]
Then, as described above, the second work coil L ₂ The opening edge of the rice cooker 1 whose opening 1b is reduced in diameter corresponds to the opening edge of the rice cooker main body 4 provided with It is supposed to.
[0035]
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 fixed and provided.
[0036]
Below the inner cover 5B of the lid unit body, a heat sink 10 made of a magnetic metal material capable of 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.
[0037]
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.
[0038]
In the configuration of the lid unit 5, the heat radiating plate 10 includes a heat radiating portion 10 a slightly protruding downward corresponding to the diameter of the reduced opening 1 a 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 portion 10b. Edge second work coil L ₂ And an induced heating portion 10c facing the other side via a predetermined gap G.
[0039]
Then, for example, a second work coil driving circuit shown in FIG. ₂ Is driven, the inductively heated portion 10c on the outer periphery of the heat radiating plate 10 is correspondingly induction-heated to generate heat, and the heat is transmitted to the heat radiating portion 10a via the seal portion 10b. From the whole surface of rice cooker 1 to rice cooker.
[0040]
On the other hand, the outer cover 5A extends deeply downward until the outer peripheral edge of the outer periphery of the inner frame portion continues to the outer peripheral surface of the shoulder member 3b while increasing the outer diameter. ₂ 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.
[0041]
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 portions of touch keys).
[0042]
(Structure of rice cooker body side control circuit part)
Next, FIG. 4 shows a configuration of a control circuit portion mainly of a microcomputer control unit for controlling rice cooking and heat retention on the rice cooker main body configured as described above.
[0043]
In the figure, reference numeral 32 is a microcomputer control unit (CPU) for controlling rice cooking and heat keeping provided with 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 inner pot 3, first and second work coil drive control circuit sections, a presence / absence detection circuit section of the inner pot 3, an oscillation circuit section, and a reset. It has a circuit section, a drive control circuit section such as a heat retention heater and a shoulder heater, a buzzer notification section, a power supply circuit section, and the like.
[0044]
Then, first, a temperature detection circuit 43 and a rice cooker detection circuit 44 provided corresponding to the inner pan temperature detection sensor S and the rice cooker detection switch LS of the center sensor on the bottom wall 1b side of the rice cooker (inner pan) 1 are described. For example, a temperature detection signal of the bottom wall 3a of the rice cooker 1 by the rice cooker temperature detection sensor S and a rice cooker detection signal by the rice cooker detection switch LS are input.
[0045]
Further, the first and second work coil drive control circuit units include, for example, first and second pulse width modulation circuits 41A and 41B, first and second synchronization trigger circuits 40A and 40B, The second IGBT drive circuits 42A and 42B, the first and second IGBTs 37A and 37B, the first and second resonance capacitors 38A and 38B, and the like. By controlling the first and second pulse width modulation circuits 41A and 41B by the first and second work coil drive control circuits of the microcomputer control unit 32, the first and second pulse width modulation circuits 41A and 41B are controlled in accordance with, for example, the rice cooking process. 1, the second work coil L ₁ , L ₂ By appropriately changing the wattage and the ON duty ratio (for example, n seconds / 16 seconds) at the same wattage, the heating temperature and heating pattern of the rice cooker 1 in each step of the rice cooking process are determined in consideration of the amount of cooked rice. Appropriate heating output control is performed so as to achieve variable water control, uniform water absorption and cooking of rice without uneven heating.
[0046]
In the present embodiment, in those cases, the first and second work coils L ₁ , L ₂ The mutual ON and OFF patterns are, for example, the first work coil L as shown in FIGS. ₁ From the second work coil L based on the end timing of the OFF pattern of the ON and OFF patterns. ₂ And the first work coil L based on the ON pattern ₁ Corresponding to the OFF pattern.
[0047]
Then, for example, in the normal heating output state where the control time is long, the first and second work coils L ₁ , L ₂ Are driven so that they do not overlap each other, so that the oscillation sound due to resonance is reduced as much as possible. On the other hand, in a process requiring a high heating output such as a cooking process, as shown in FIG. The first and second work coils L only during the short period t ₁ , L ₂ By driving them in a superposed manner, it is possible to easily obtain an effective high heating output.
[0048]
Moreover, they are each work coil L ₁ , L ₂ This is simply realized by changing the set time n of the duty ratio setting timer in the backward calculation direction without changing the basic heating control pattern.
[0049]
In a process in which the control time is long and a normal heating output is sufficient, such as a boiling maintaining process that does not require a particularly large heating output, as shown in FIG. ₁ , L ₂ Work coil L without overlapping each other's ON timing. ₁ , L ₂ Heating is controlled by each heating output so that oscillation noise is not generated as much as possible.
[0050]
On the other hand, in the high heating output step, as shown in FIG. ₁ , L ₂ The first and second work coils L are configured so that their mutual ON patterns overlap for a predetermined period. ₁ , L ₂ It is possible to obtain a desired high heating output within the range of the maximum allowable power value in which the respective heating outputs are synergistic.
[0051]
In these cases, for example, as is apparent from the time chart of FIG. 6, in the normal heating output step, the first and second work coils L are controlled within one control cycle of 16 seconds. ₁ , L ₂ Are OFF in some cases. Further, the first and second work coils L ₁ , L ₂ May be alternately switched from ON to OFF and from OFF to ON at the opposite timing, for example.
[0052]
Further, the first and second work coils L ₁ , L ₂ May start the ON control from either side. However, from the viewpoint of giving priority to the detection of empty cooking, as shown in FIGS. ₁ It is preferable to start the ON control from.
[0053]
Furthermore, both the first and second work coils L are used during the heat insulation. ₁ , L ₂ In the case of using the two work coils L, the large output is not required. ₁ , L ₂ It is not necessary to perform the ON control by superimposing, but it is also possible to perform the ON control by superimposing, for example, at the time of reheating.
[0054]
Further, in the above case, the first and second work coils L ₁ , L ₂ Is the first work coil L when cooking rice. ₁ The ON time is longer, and the second work coil L ₂ Make the ON time longer.
[0055]
Further, by controlling the warming heater drive circuit 33 and the shoulder heater drive circuit 34 by the warming heater drive control circuit and the shoulder heater drive control circuit of the microcomputer control unit 32, respectively, for example, according to the warming or rice cooking heating process, Heating heater H ₁ , Shoulder heater H ₂ By appropriately changing the ON duty ratio (for example, n seconds / 16 seconds), the heating temperature and the heating pattern of the rice cooker 1 in each step of the warming or the rice heating step can be considered in consideration of the actual amount of cooked rice and the amount of water. Appropriate output control for appropriately variable control is performed.
[0056]
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. A desired rice cooking or heat retention pattern is set according to the content, and the desired rice cooking or heat retention is performed by appropriately operating the rice heating control means or the heat retention control means.
[0057]
Therefore, the user can use the input switches 22a to 22h to cook or keep rice, timer reservation, reservation time setting, white rice or brown rice, fast-cooking, rice porridge, mash or soft, sushi, cook, etc. If you select and set various kinds of rice cooking or steaming, such as steaming, normal heat insulation or low temperature insulation, and heat insulation function, the corresponding function contents will be cooked or steamed through the above-mentioned recognition means of the microcomputer control unit 32, and the heat insulation will be performed. 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.
[0058]
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).
[0059]
(Cooking rice control)
Next, with reference to the flowchart of FIG. 5, the contents of the rice cooking to heat keeping control by the microcomputer control unit 32 will be described.
[0060]
That is, as shown in the flowchart of FIG. 5, the control is started by turning on the rice cooker switch 22a.
[0061]
Then, first, step S ₁ To enter the water absorption process, and step S ₂ And the first and second work coils L ₁ , L ₂ Is set to a predetermined power, and heated to the water absorption temperature (40 to 45 ° C.) in the ON / OFF pattern of FIG. After that, the water absorption heating at the same water absorption temperature is executed within a predetermined time while the output is slightly adjusted in the ON / OFF pattern of FIG.
[0062]
Next, when the water absorption step is completed, step S ₂ To the first and second work coils L ₁ , L ₂ Is set to full power A (W) (wattage: maximum, duty ratio: 16/16), and heating is performed in the ON / OFF pattern of FIG. Then, further step S ₃ The temperature T of the rice cooker 1 is detected by the temperature detection sensor S, and the temperature T is set to a predetermined reference number T for determining the total number. ₁ It is determined whether the temperature is at least ℃.
[0063]
This step S ₃ As a result of the determination, the temperature T of the rice cooker 1 is equal to the total number determination reference ₁ If the temperature is not higher than ℃, the above step S ₂ Returning to FIG. 7, while the temperature increase heating after the water absorption heating is continued with the full power A (W) of the ON / OFF pattern of FIG. ₄ Then, the total number determination control is started.
[0064]
Then, further step S ₅ The temperature T of the rice cooker 1 is detected again, and the detected temperature T is equal to the total number determination reference temperature T. ₂ It is determined whether the temperature is equal to or higher than ° C.
[0065]
On the other hand, step S ₅ The temperature of the rice cooker 1 still determined to be NO as a result of the determination in the above is the sum determination reference temperature T. ₂ If the temperature has not reached ℃ or more, the same temperature T ₂ Step S until the temperature reaches ₄ ~ S ₅ Is repeated. On the other hand, the result of the determination is YES, and the total number determination reference temperature T ₂ ℃, the above T ₁ ° C to T ₂ The total number is determined based on the counting time until the temperature reaches ° C.
[0066]
Then, further step S ₆ , S _Thirteen , S _Fifteen Then, it is determined whether the result of the total number determination is a large amount, a medium amount, or a small amount. ₇ , S ₁₄ , S _Fifteen For example, the work coil L sequentially becomes smaller for each rank in accordance with the large number, medium amount, and small amount of the determined total number. ₂ , The heating outputs C (W), D (W), and E (W) are set, and the subsequent step S ₈ Then, the heating in each cooking step is executed with the ON / OFF pattern of FIG. 7 and full power. Then, when it is detected that the temperature of the rice cooker 1 has reached the boiling temperature of 100 ° C., the process proceeds to step S. ₉ Then, the process is shifted to the boiling maintaining step, and the boiling state is maintained in the ON / OFF pattern shown in FIG. As a result, the rice is eventually cooked.
[0067]
Therefore, the next step S ₁₀ To determine whether or not the temperature T of the rice cooker 1 has reached the cooking completion temperature of 130 ° C. or higher. ₁₁ (“ON” and “OFF” patterns in FIG. 6 are used). When the “mura” step is completed, step S is further performed. ₁₂ (The ON / OFF pattern of FIG. 6 is used) and the control is terminated.
[0068]
As described above, in the configuration of the electric rice cooker according to the present embodiment, a rice cooker capable of electromagnetic induction heating, a rice cooker main body storing the rice cooker, and the stored rice stored in the rice cooker main body side. An electric rice cooker comprising: a plurality of electromagnetic induction heating means for electromagnetically heating a cooking vessel; and heating control means for drivingly controlling the plurality of electromagnetic induction heating means at predetermined ON and OFF timings. For the ON / OFF pattern of the electromagnetic induction heating means, the ON pattern of the other induction heating means is set based on the end timing of the OFF pattern of the ON / OFF pattern of one of the electromagnetic induction heating means. It is characterized in that the ON pattern is made to correspond to the OFF pattern based on the above reference.
[0069]
According to such a configuration, for example, in a normal heating output state having a long control time, by driving a plurality of electromagnetic induction heating means such as a plurality of work coils so as not to overlap each other, oscillation noise due to resonance is reduced as much as possible. On the other hand, in a process requiring high heating output such as a cooking process, it is possible to easily obtain an effective high heating output by driving a plurality of work coils in an overlapping manner only for a necessary period for output setting. It becomes.
[0070]
Moreover, they can be easily realized only by changing the set time of the duty ratio setting timer in the backward calculation direction without changing the heating control pattern which is the basis of each electromagnetic induction heating means.
[0071]
Further, in the above configuration, in the same configuration, the ON patterns of the plurality of heating means are not overlapped in the normal heating output step.
[0072]
As described above, in a process in which the control time is long and a normal heating output is sufficient, such as a boiling maintaining process that does not particularly require a large heating output, the ON timings of the plurality of electromagnetic induction heating units are overlapped. If the heating is controlled by the heating output of each of the electromagnetic induction heating means, the oscillation sound can be prevented from being generated as much as possible.
[0073]
Further, in the above configuration, in these configurations, in the high heating output step, the ON patterns of the plurality of heating units are configured to overlap for a predetermined period.
[0074]
With such a configuration, it is possible to obtain a desired high heating output within the range of the maximum allowable power value in which the heating outputs of the plurality of electromagnetic induction heating means are synergistic.
[0075]
Further, the above configuration is characterized in that, in those configurations, the high heating output step is a full power heating step such as a temperature raising step, a cooking step, or a reheating step.
[0076]
In such a temperature raising step after completion of the water absorption heating step, a cooking step or a reheating step after completion of rice cooking, high heating output with full power is generally required.
[0077]
Therefore, in such a process, when the ON timings of the plurality of electromagnetic induction heating means are overlapped with each other, the outputs of the respective electromagnetic induction heating means can be effectively synergized to realize a required high heating output.
[0078]
Further, in the above configuration, in those configurations, the plurality of electromagnetic induction heating means such as the first and second work coils are provided on the bottom of the rice cooker main body and the first work for induction heating the bottom of the rice cooker. A coil and a second work coil on the shoulder of the rice cooker main body for heating the edge of the opening of the rice cooker and the heat radiation plate of the inner lid.
[0079]
Thus, the above-mentioned plurality of electromagnetic induction heating means are provided at the bottom of the rice cooker main body for induction heating the bottom of the rice cooker, and at the shoulder of the rice cooker main body at the edge of the rice cooker opening edge. And a second work coil that heats the inner lid heatsink portion, the two work coils have a positional relationship between the lower part and the upper part of the rice cooker main body, which are hardly influenced by each other, in a large distance. It will be.
[0080]
Therefore, in the same configuration, when they are simultaneously turned on at the time of high heating output as described above, there is little effect and no large oscillation sound is generated.
[0081]
As a result, according to the electric rice cooker of the present embodiment, in the normal heating output state having a long control time, the oscillation sound is reduced as much as possible by driving the electromagnetic induction heating means such as a plurality of work coils so as not to overlap. On the other hand, in a process requiring high heating output such as a cooking process, an effective high heating output can be obtained by driving a plurality of work coils in an overlapping manner.
[0082]
Moreover, they can be easily realized only by changing the set time of the duty ratio setting timer without changing the heating control pattern which is the basis of each electromagnetic induction heating means.
[0083]
Further, in the high heating output step such as the above-described full power step, the total control time is shorter than that in the ordinary heating output step such as the boiling maintaining step, and the oscillation sound is less likely to cause a problem.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a configuration of an entire rice cooker main body of an electric rice cooker according to an embodiment of the present invention.
FIG. 2 is an enlarged sectional view of an upper portion of the rice cooker main body of the electric rice cooker.
FIG. 3 is an enlarged sectional view of a lower portion of the rice cooker main body of the electric rice cooker.
FIG. 4 is an electric circuit diagram of first and second work coil drive control circuit portions which are main parts of the electric rice cooker.
FIG. 5 is a flowchart showing a control operation of the electric rice cooker during rice cooking to warming.
FIG. 6 is a time chart showing ON and OFF patterns of first and second work coils in a heating step of a normal output of the electric rice cooker.
FIG. 7 is a time chart showing ON and OFF patterns of first and second work coils in a high-power heating step of the electric rice cooker.
FIG. 8 is a time chart showing ON and OFF patterns of first and second work coils in a heating step of a normal output 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 IGBT, 37B is a second IGBT, 38A is a first resonance capacitor, 38B is a second resonance capacitor, 30 is a buzzer, L ₁ Is the first work coil, L ₂ Is a second work coil.

Claims (5)

A rice cooker capable of electromagnetic induction heating, a rice cooker main body containing the rice cooker, a plurality of electromagnetic induction heating means on the rice cooker main body side for electromagnetic induction heating the stored rice cooker, An electric rice cooker comprising: a heating control means for drivingly controlling the electromagnetic induction heating means at predetermined ON and OFF timings, wherein the ON / OFF pattern of the plurality of electromagnetic induction heating means is any one of The ON pattern of another induction heating means is set based on the end timing of the OFF pattern of the ON and OFF patterns of the electromagnetic induction heating means, and the ON pattern is made to correspond to the OFF pattern based on the above reference. Characterized electric rice cooker. 2. The electric rice cooker according to claim 1, wherein in a normal heating output step, the ON patterns of the plurality of heating means are not overlapped with each other. 2. The electric rice cooker according to claim 1, wherein in the high heating output step, the ON patterns of the plurality of heating means overlap each other for a predetermined period. The electric rice cooker according to claim 3, wherein the high heating output step is a full power heating step such as a heating step, a cooking step, or a reheating step. The electromagnetic induction heating means includes a first work coil at the bottom of the rice cooker main body for induction heating the bottom of the rice cooker, a rice cooker opening edge at the shoulder of the rice cooker main body, and an inner lid heat sink. 5. The electric rice cooker according to claim 1, comprising a second work coil for heating a portion.

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