JP4391039B2 - Electric rice cooker - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a rice cooker used for home use and business use.
[0002]
[Prior art]
In recent years, electric rice cookers using electromagnetic induction heating have been proposed. In FIG. 3, reference numeral 1 denotes a cylindrical body whose upper surface is open. Inside the body 1, a coil base 2 which is a storage portion for the pan 3 is disposed, and the coil base 2 is a bottomed cylinder made of a nonmetallic material. It is shaped into a shape. An induction coil 4 serving as a heating means is disposed outside the coil base 2 so as to face the bottom surface and the bottom side surface portion of the pan 3. In the electric rice cooker, first, a predetermined amount of cooked rice and water are put into a pan, and then the induction coil 4 is energized to heat the pan 3. Cooking rice is performed by energizing with a predetermined energization pattern.
[0003]
[Problems to be solved by the invention]
However, in the rice cooker, vegetation is generated in the lower central part of the pan, and the taste is remarkably lowered.
[0004]
Moreover, if the said rice is stirred after cooking rice, the said bech part will collapse and will adhere to the surface of the rice cooked normally. As a result, the rice surface became sticky and became a dumpling, which significantly reduced the taste.
[0005]
In particular, varieties that are called soft rice such as Uonuma Koshihikari and Sasanishiki, and freshly picked rice are prone to the above phenomenon, and special techniques such as reducing the amount of cooking rice and reducing water consumption. I was cooking rice.
[0006]
In addition, because the heating means performs heating concentrated only on the lower part, it is easy for the bottom surface of the pan to be burnt, making it difficult to achieve the “baking process” required in the late rice cooking process, and the side surface of the pan becomes soggy A decrease in taste occurred.
[0007]
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a rice cooker that improves the taste by suppressing the betting at the lower center of the pan.
[0008]
[Means for Solving the Problems]
In order to solve the above problems, the present invention provides a first heating means for heating the bottom surface of the pan, and a second heating means for heating the bottom side surface of the pan located outside the first heating means. When a third heating means for heating the side surface portion of said pot, said control means for controlling the energization of the first and second and third heating means, cook up 1 and cook up sequentially rice to deploy 2 The cooking 1 is energized by the second heating means and the third heating means, and the cooking 2 is energized by the first heating means and the second heating means. is there.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
The invention according to claim 1 is located on the outside of the body, a pan detachably accommodated in the body, a first heating means for heating the bottom surface of the pan, and the first heating means. Second heating means for heating the bottom side surface portion of the pan, third heating means for heating the side surface portion of the pan, and control means for controlling energization of the first, second and third heating means, And a rice cooking process that sequentially develops the cooking 1 and the cooking 2 , the cooking 1 is energized by the second heating means and the third heating means, and the cooking 2 is supplied with the first heating means. And by energizing the second heating means, when heated by the second bottom heating means in the initial rice cooking process, the outer convection through which the water in the cooked food passes through the pan side portion is promoted and the temperature of the upper cooking food rises. To do. Thereafter, by energizing both the first heating means and the second heating means, the temperature of the upper part of the cooked food rises faster than the lower layer part, so that overcooking of the lower part of the cooked food can be prevented.
[0010]
Invention of Claim 2 is equipped with the temperature detection means which detects the temperature of a pan, and after a rice cooking start, until the temperature of a temperature detection apparatus becomes a predetermined value, it continues cooking 1 process, and the amount of rice cooking and the amount of water additions are continued. Even if it changes, it is fed back by the temperature detection device, so the rice cooking performance is more stable.
[0011]
In the invention according to claim 3, when the amount of cooked rice is known in advance by continuing one step of cooking for a predetermined time after the start of cooking, the cooked rice becomes more stable.
[0012]
Fourth aspect of the present invention, the rice cultivar cooking, by varying the energization amount for energizing the second heating means, food upper portion and a lower portion by controlling the energizing time of the second heating means Can control the temperature difference. That is, the longer the energization time of the second heating means, the wider the temperature difference between the upper and lower portions of the cooked product. When this temperature difference is utilized, for example, soft rice tends to promote the alpha conversion of rice with a small amount of heat. On the other hand, hard rice does not become sticky even if it is cooked a little too much, but it has characteristics that it is difficult to promote alpha conversion unless heated with a large amount of heat. Therefore, in soft rice, the energization time of the second heating means is lengthened to suppress the lower layer portion, and in hard rice, the energization time of the second heating means is shortened to increase the heating amount of the lower layer portion and become α. It is easy to cook rice with reduced cooking unevenness by promoting.
[0013]
The invention according to claim 5 can obtain the same effect as that of the invention according to claim 4 even in new rice and old rice.
[0014]
【Example】
An embodiment of the present invention will be described below with reference to FIGS. In the figure, 10 is a body whose upper surface is open, 11 is a coil base formed into a bottomed cylindrical shape with a non-metallic material, and 12 is a pan, which is detachably attached to the body 10. An inner coil 13 serving as a first heating means is disposed at a portion of the coil base 11 that faces the bottom of the pan 12. In addition, an outer coil 14 serving as a second heating means is disposed on a portion of the coil base 11 facing the bottom side of the pan 12. A side coil 15 is a third means provided to face the side surface of the pan 12. Reference numeral 16 denotes a circuit board through which a current for generating an alternating magnetic field is supplied to the inner coil 13, the outer coil 14, and the side coil 15. Reference numeral 17 denotes a bottom sensor which is a temperature detecting means for detecting the temperature of the pan, and is provided on the coil base and abuts on the center of the pan bottom of the pan 12 to detect the temperature of the pan 12. Reference numeral 17 denotes an outer lid, and a lid sensor 18 serving as a boiling detection means is provided on the upper portion of the outer lid 17 to detect the temperature of steam generated from the food 19 and detect boiling. Further, the mass of the base rice in this embodiment is 7 kg, the input of the inner coil 13 and the outer coil 14 is 6.5 kw, and the input of the side coil is 2 kw.
[0015]
The operation in the above configuration will be described below. When the cooked food 19 such as rice water is put into the pan 12 and a current is passed from the circuit board 16 that operates the rice cooker to the outer coil 14 and the side coil 15, the outer coil 14 and the side coil 15 generate an alternating magnetic field and the pan. 12 heats and the temperature of the foodstuff 20 rises. Rice cooking is started and cooked by the heating process shown in FIG. During the heating process, “cooking 1” is mainly cooked by the outer coil 14 and the first side coil 15 is energized as necessary.
[0016]
During the cooking process of cooking rice, when the boiling reaches a temperature that uniformly raises the temperature of the cooked rice, the rice that is the cook absorbs water, the upper layer of the cooked food loses water around the rice relatively quickly, and cooking is reduced, The bottom of the cooked food was overcooked due to the presence of water around the rice until the end, and it was easy to bet.
[0017]
Therefore, when the outer coil 14 and the side coil 15 are energized and heated in the “cooking 1” process, which is the initial process of cooking rice, the water in the cooking 19 becomes an external convection passing through the side of the pan, and the temperature of the upper layer of the cooking 19 increases. To rise. After that, by heating both the inner coil 13 and the outer coil 14 with “cooking 2”, the temperature of the upper layer of the food has already risen faster than the lower layer, so that overcooking of the lower part of the food 19 is prevented. it can. Further, the temperature difference between the upper layer and the lower layer of the cooked product can be controlled by controlling the time of “cooking 1”. That is, the longer the energization time of “cooking 1” is, the wider the temperature difference between the upper layer portion and the lower layer portion of the food.
[0018]
FIG. 3 is a graph showing the temperature of the cooked food when the “cooking 1” time is varied.
In the figure, a indicates the temperature of the lower layer portion of the food 19, b indicates the temperature of the middle layer portion, and c indicates the temperature of the middle layer portion. The time of “cooking 1”, (A) is “cooking 1” time 0, (B) is “cooking 1” time standard, (C) “cooking 1” time is long Indicates. As is clear from the figure, the longer the “cooking 1” time, the wider the difference between the temperature a of the lower layer and the temperature c of the upper layer. According to the experiments by the inventors, the rice in (A) was sticky in the lower layer and deteriorated the taste. Moreover, the rice in (C) became a tattered texture because the lower layer became deficient. The rice of (B) had almost no unevenness in the top and bottom of the rice and the taste was good.
[0019]
Also from the said experiment, the taste of rice can be improved by optimizing the time of "cooking 1".
[0020]
In addition, when this temperature difference is used, for example, new rice tends to be promoted to α-formation of rice with a small amount of heat. On the other hand, old rice is less likely to become a mess even if it is cooked a little too much, but it has the characteristic that it is difficult to promote alpha conversion unless heated with a large amount of heat. Therefore, in the new rice, the energization time of the second heating means is lengthened, thereby suppressing the lower layer portion, and in old rice, the energization time of the lower heating portion is increased by shortening the energization time of the second heating means. Let Similarly, the same effects as described above can be obtained depending on the variety of rice.
[0021]
Moreover, the result of the rice cooking state when the outer coil 14 and the side coil 15 are energized at the same time in the “cooking 1” process and when only the outer coil 14 is energized is substantially the same, but the outer coil 14 and the side coil Since the unevenness of the top and bottom of the cooked food 19 is expanded more quickly when the power is supplied to 15 at the same time, the same effect can be obtained in a short time.
[0022]
In addition, the time of "cooking 1" of a present Example is preset by the program. In the case of a rice cooker incorporated in a rice cooking system as in this embodiment, the rice cooking performance is more stable when set in advance because the amount of rice cooking and the amount of water added are set in advance. However, when the amount of cooked rice cannot be set in advance as in a home-made rice cooker, the rice cooking performance is more stable when energized until the temperature of the bottom sensor 17 reaches a predetermined value. As described above, it is only necessary to select the one where rice cooking is stable according to the use conditions of the rice cooker.
[0023]
In “cooking 2”, which is the middle stage of the rice cooking process, it is necessary to raise the temperature in the cooked food 19 uniformly and quickly. Therefore, in this step, both the inner coil 13 and the outer coil 14 are energized and energized with the maximum power. At this time, if the side coil 15 is also energized, the boiling time can be shortened. However, since the side coil 15 is heated only above the cooked item 19, uneven cooking is increased. Therefore, the side coil 15 is better when not energized, so that the rice is better. Therefore, when both the inner coil 13 and the outer coil 14 are energized, the side coil 15 is forcibly turned off. In this case, the maximum input of this embodiment is 13 kW, and the power supply capacity can be reduced as compared with 15 kW when all the heating coils are energized.
[0024]
Next, “Cooking 1” and “Cooking 2”, which are the latter part of the rice cooking process, but “Cooking 2”, which is the middle part of the rice cooking process, heats the surface where the inner coil 13 and the outer coil face each other more than the other parts. Therefore, a large amount of the cooked food 19 in contact with the nearby pan is heated, so that the cooked rice 19 in contact with the pan surface receives a great deal of heat, and starch granules are eluted, and the inner coil 13 and the surface of the pan that is in contact with the outer coil 14 increases the area of attachment to the surface of the pan. At this time, if the heating is further continued in the inner coil 13 and the outer coil 14, since the adhesion area between the starch grains and the pan surface is large, the heat flow to the starch grains is increased, and the starch flow is colored and burnt. Here, by using the side coil 15 without the adhesion of starch grains, the concentrated heating to the starch is reduced, so that the heating can be continued without worrying about the occurrence of scorching. By continuing the heating as described above, the side surface of the pan 12 can be kept at 100 ° C. or higher, so that whitening that occurs on the side surface of the pan 12 can be suppressed and the temperature in the rice serving as the cooked food 19 is 100. Since it can be maintained at a level higher than ℃, it is possible to achieve sufficient alpha conversion, and surface water (free water) present on the surface of rice can also be removed, providing a rice cooker with an improved beam and sweetness. can do.
[0025]
As is clear from the above description, in the latter stage of the rice cooking process, the side coil 15 is energized to suppress scorching and maintain the temperature in the cooked food at 98 ° C. or higher, thereby promoting the alpha conversion of the cooked rice 19. The surface water adhering to the rice is blown off to realize a so-called “baking process”, which improves the rice paste and greatly improves the taste.
[0026]
【The invention's effect】
As mentioned above, according to invention of Claim 1, the rice cooker which suppressed the stickiness of the pot center part more and improved the taste significantly can be provided.
[0027]
Moreover, according to invention of Claim 2, even if the amount of rice cooking changes, the rice cooker with the stable rice cooking performance can be provided.
[0028]
Moreover, according to invention of Claim 3, the rice cooker which stabilized the rice cooking performance when the amount of rice cooking is known beforehand can be provided.
[0029]
Moreover, according to the invention of Claims 4 and 5, even if there is a difference in new rice / old rice and rice quality of rice, it is possible to provide a rice cooker that can easily cook rice without requiring a special technique.
[Brief description of the drawings]
FIG. 1 is a cutaway longitudinal sectional view of an electric rice cooker in an embodiment of the present invention. FIG. 2 is a diagram showing a rice cooking process of the electric rice cooker. FIG. 3 is a diagram showing a temperature rise of the electric rice cooker. ] Cutaway vertical section of rice cooker in the conventional example [Explanation of symbols]
10 body 12 pan 13 inner coil (first heating means)
14 Outer coil (second heating means)
15 Side coil (third heating means)
17 Bottom sensor (temperature detection means)
18 Lid sensor (boiling detection means)

Claims (5)

A body, a pan detachably housed in the body, a first heating means for heating the bottom surface of the pan, and a bottom side surface of the pan located outside the first heating means and second heating means, and a third heating means for heating the side surface portion of the pot, and control means for controlling the energization of the first and second and third heating means,-out 1 and炊up cooked up A rice cooking process in which 2 is sequentially developed, the cooker 1 is energized with a second heating means and a third heating means, and the cooker 2 is provided with a first heating means and a second heating means. An electric rice cooker that is energized.   The electric rice cooker according to claim 1, comprising a temperature detection means for detecting the temperature of the pan and continuing the cooking process until the temperature of the temperature detection device reaches a predetermined value after the start of rice cooking.   The electric rice cooker according to claim 1, wherein one step of cooking for a predetermined time is continued after the start of rice cooking. The electric rice cooker according to claim 2 or 3, wherein the energization amount for energizing the second heating means is varied depending on the rice varieties to be cooked. The electric rice cooker according to claim 2 or 3, wherein the amount of energization for energizing the second heating means is varied depending on the quality of rice such as new rice and old rice, rice milling conditions and the number of elapsed days of rice polishing.

Images