JP2011217783A - Electric rice cooker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric rice cooker provided with a Sushi rice boiling course wherein uneven boiling is eliminated and rice seasoned with vinegar that has more Umami taste and is favorably vinegared can be boiled.SOLUTION: The electric rice cooker carries out a series of rice cooking steps including: a water absorption step at which a predetermined quantity of water is absorbed by rice to be boiled in a pot; a start heating step at which the rice that absorbed water is heated until the water is boiled; a boiling sustaining step at which the interior of the pot is kept in a boiled state after the completion of the start heating step; and a steaming step at which the rice is steamed after the completion of the boiling sustaining step. When the Sushi rice course is selected, a controller closes a pressure valve after the water absorption step and carries out the start heating step to increase the temperature and pressure of the interior of the pot. After the completion of the start heating step, the boiling sustaining step is entered. At the boiling sustaining step, it makes the boiling sustaining power larger than the boiling sustaining power in the standard course and forcibly opens the pressure valve by a predetermined number of times. Thereafter, it maintains the open state and carries out the subsequent rice cooking step.

Description

  The present invention relates to an electric rice cooker, and more particularly to an electric rice cooker provided with a sushi rice rice cooker course in addition to a white rice / standard rice cooker course.

  Electric rice cookers (hereinafter referred to as rice cookers) are already a necessity in general households, and various types of rice cookers have been commercialized. This type of rice cooker is roughly divided into a type that cooks the pressure in the pan at about normal pressure during cooking and a type that cooks by raising the pressure to a predetermined pressure. In recent years, these rice cookers have been equipped with microcomputers, which can be used to adjust various rice cooking courses, for example, rice rice cooking courses according to rice varieties such as white rice and brown rice, hard and soft. Now, you can do your favorite rice cooking course where you can cook your favorite rice and sushi rice rice cooking course that cooks sushi rice. All of these rice cooking courses have a water absorption process in which a predetermined amount of water is absorbed by the rice in the pot, a rising heating process in which the pot is heated and boiled at once after water absorption, and this boiling state is maintained to maintain the rice starch. Rice is cooked by a series of rice cooking steps including a boiling maintaining step of gelatinizing and cooking, a steaming step of removing extra water from the cooked rice and further promoting gelatinization.

  For example, Patent Document 1 below describes a normal pressure rice cooker having a rice cooking course such as sushi rice.

  This rice cooker includes a steam port for releasing steam generated during rice cooking, a steam port opening and closing device for opening and closing the steam port, a rice cooking sequence selecting means for allowing the user to select a cooking menu, and a steam port opening and closing device. And a control device for controlling and executing a series of rice cooking processes. The cooking menus are, for example, katakana, soft, soft rice and sushi rice menus. Moreover, a series of rice cooking processes are a water absorption process, a temperature rising process, a cooking process, a boiling maintenance process, and a supplementary cooking process. In this rice cooker, the pressure in the pan rises slightly during rice cooking, but the upper limit pressure is 1.01 atm.

  In this rice cooker, when the menu is normally selected by the rice cooking sequence selection means, the steam inlet is closed in the water absorption process, and this closed state is continued until the cooking process. In the subsequent boiling maintenance process and additional cooking process, this steam opening is opened and closed intermittently 3 to 7 times every predetermined time, and this rice cooking menu is usually executed.

  Further, when the sushi rice menu is selected as the rice cooking sequence selection means, the steam opening is closed in the water absorption process, and the steam opening is opened as the energization of the heating means is started in the next temperature raising process. Thereafter, this open state is continued until the cooking process, the boiling maintenance process, and the additional cooking process, and this sushi course is executed.

  Moreover, the following patent document 2 describes the pressure-type rice cooker provided with the same rice cooking courses, such as sushi rice.

  This rice cooker is a pot that contains rice and rice containing water, a rice cooker body that houses the pot and has heating means for heating the cooked rice in the pot, and a lid that closes the opening of the rice cooker body A pressure valve for communicating or blocking the body, the inside of the pan and the outside air, a pressure valve opening mechanism attached to the pressure valve for forcibly opening the pressure valve, and controlling the heating amount of the heating means and the pressure valve A control device that performs a series of rice cooking processes that are forcibly opened for a predetermined unit time during rice cooking, and a white rice / standard (normal) rice cooking course (hereinafter referred to as the standard course), white rice / applied rice (sushishi) rice cooking A selection means that allows a user to select an arbitrary rice cooking course from a group of rice cooking courses including a course (hereinafter referred to as a sushi rice course).

Hereinafter, with reference to FIG. 12, FIG. 13, the rice cooking process of this rice cooker is demonstrated. In addition, FIG. 12, FIG. 13 shows the rice cooking process of the rice cooker described in the following patent document 2, FIG. 12 is the rice cooking process figure of a standard course, and FIG. 13 is the rice cooking process figure of a sushi rice course. These rice cooking process diagrams show temperature and pressure changes in the pan.
(■) Standard Course When the standard course is selected by the selection means, the control device executes the following rice cooking process. Referring to FIG. 12, first, in the water absorption step, the heating means is energized with the pressure valve opened, and the temperature in the pan is set at a predetermined water absorption temperature (55 ° C.) over a predetermined time. Is executed. When this water absorption process is completed, the process proceeds to the start-up heating process. In this start-up heating process, the pressure valve is closed and at the same time the full power is supplied to the heating means to bring the pot into a pressurized state and boil the pot. Put it in a state. A steam temperature sensor installed in a lid or the like detects the steam temperature in the pan, and when the steam temperature reaches a predetermined temperature (75 ° C.), the process proceeds to the next boiling maintenance step. In this boiling maintenance step, the pressure valve opening mechanism is operated to forcibly open the pressure valve a plurality of times in a predetermined unit time. When the pressure valve is opened, the state in the pan is reduced from the pressurized state to the vicinity of the atmospheric pressure at once, and a pressure fluctuation occurs in the pan, and this pressure fluctuation is intermittently repeated a plurality of times. Due to the intermittent opening of the pressure valve, the pressure in the pan fluctuates greatly, and each time a severe boiling phenomenon, so-called bumping phenomenon occurs in the pan, a large amount of bubbles is generated. At the same time, the rice grains in the center of the pan move sideways in the pan, or the rice grains in the pan are efficiently stirred by repeating the reverse movement. By this stirring, sufficient heat is applied to the whole rice grain, and uneven heating is eliminated. In addition, by this stirring, sticky paste-like juice (hereinafter referred to as “rice bean”) containing a umami component is also efficiently mixed, and the periphery of the rice grains is coated with this rice bean. Since rice balls contain a large amount of umami ingredients, the cooked rice is coated with this rice cake and becomes delicious. In this boiling maintenance process, after the pressure valve is forcibly opened a plurality of times, the remaining boiling maintenance process is continued without performing such a forced opening operation. In the remaining boiling maintenance step, the pressure valve is repeatedly opened and closed in a short time so that a substantially constant pressure state is maintained by the balance between the weight of the ball closing the valve opening and the pressure in the pan. After the boiling maintaining process is continued for a predetermined time, when the pan bottom sensor installed in the vicinity of the pan bottom detects a predetermined pan bottom temperature (130 ° C.), the controller stops energizing the heating means and shifts to the steaming step 1. At this time, the opening operation of the pressure valve is not performed. When this steaming process ends, the process proceeds to the additional cooking process, and the pressure valve is opened and reheating is performed by the heating means. When this reheating is completed, the process proceeds to the steaming process 2 and the series of rice cooking processes of this standard course is completed.
(■) Sushi rice course When the sushi rice course is selected, the control device executes the following rice cooking process. The sushi rice course is cooked in the same manner as the standard course. The contents different from this standard course will be described below.

  Referring to FIG. 13, in the water absorption step, the pressure valve is opened and the water absorption time is shorter than the standard course time (15 minutes) (10 minutes). This shortening of the water absorption time reduces the water content of rice. After the end of this water absorption process, the start-up heating process is performed by heating the pan with the total heating amount (full power) with the pressure valve opened. When the steam temperature sensor detects the predetermined steam temperature (75 ° C.), the process proceeds to the boiling maintenance process, and this maintenance process is continued. When the pot bottom temperature sensor detects the predetermined pot bottom temperature (130 ° C.), the heating is stopped. To steaming step 1. Even in this boiling maintaining step, the pressure valve is maintained in an open state, and the pressure in the pan is always close to atmospheric pressure. After the steaming process 1, the process proceeds to the additional cooking process and the steaming process 2, and the series of rice cooking processes of the sushi rice course is completed. In this sushi rice course, you can cook rice that has reduced water absorption more than necessary (rice that is easy to grasp as sushi or has a texture as a pilaf).

As described above, the (■) standard course and the (■) sushi rice course are executed. When the opening and closing states of the pressure valves in these rice cooking courses are summarized, the standard course is closed and added in the start-up heating process. During the pressure and boiling maintenance process, the closed / pressurized state and the open / depressurized state are repeated, and during the steaming process, it becomes open (approximately atmospheric pressure), while the sushi rice course is open during the entire process (approximately atmospheric pressure). ) State.

Japanese Patent No. 3536495 (paragraphs [0016], [0022], FIG. 34) Japanese Patent No. 4094020 (paragraphs [0064] and [0074], FIG. 12)

  According to the rice cooker of the above-mentioned patent document 1, the rice obtained by cooking in the sushi rice course is harder than the rice cooked in the standard course, and on the other hand, it is cooked with less stickiness and suitable for vinegar combination Sushi rice is cooked. However, this rice cooker is a normal pressure type, and according to the structure and a series of rice cooking processes, the stirring of the cooked rice during cooking may be insufficient. As a result, it becomes difficult to apply sufficient heat to the whole rice grain, that is, heating unevenness, that is, a temperature difference occurs between the rice grain in the center of the pot and the rice grain on the inner wall side, and uneven cooking may occur, Due to the lack of stirring of the cooked rice, the umami component may not spread evenly over the whole rice grains, resulting in a lack of deliciousness.

Moreover, in the rice cooker of the said patent document 2, a pressure valve is open | released during rice cooking in the rice cooking of a standard course (above (■)), and the intense boiling phenomenon generate | occur | produces in a pan by opening of this pressure valve, Since the cooked rice is efficiently stirred, uneven heating, that is, uneven cooking is eliminated. Moreover, the cooked rice is coated with a umami-flavored rice, so delicious rice is cooked. However, in this rice cooker, the pressure valve opening control is performed in the standard course, but in the rice cooking of the sushi rice course ((■) above), this opening control is not performed and the whole rice cooking process is in an open state. . Therefore, the problem which the rice cooker of the said patent document 1 has remains as it is, and is not solved. In addition, if you try to make rice cooked in this standard course into sushi rice, the rice flavor is coated around the grain of rice, which prevents vinegar from entering during vinegar combination, making it unsuitable as sushi rice . In particular, it cannot be used at sushi shops that use Edo-mae sushi.

  In addition, when a large amount of rice is cooked at the same time, gas cookers are often used in place of this kind of electric rice cooker, but this gas cooker can cook delicious rice as described above. Can not. From this situation, for example, a sushi restaurant or the like demands the commercialization of a large electric rice cooker that can cook a large amount of delicious sushi rice at once.

  Therefore, the present inventors have been able to cook delicious rice with the rice cooker of Patent Document 2, but since the above problem is inherent, a method for solving this problem was studied. As a result, the number of opening of the pressure valve is limited to the minimum number of times in the boiling maintenance process of the sushi rice course, and the boiling maintenance power is increased more than the boiling maintenance power in the standard course, so that the cooking unevenness is eliminated and the taste component The present invention has been completed by ascertaining that the rice balls are properly mixed and that vinegar can be added well.

  The present invention is a sushi rice cooking course that solves the problems of the prior art and is based on the above knowledge, eliminates uneven cooking, and can cook sushi rice with umami and good vinegar. It aims at providing the rice cooker provided with.

  In order to achieve the above-mentioned object, the invention according to claim 1 is a rice cooker provided with a pot for storing a rice cooked product composed of rice and water, and a heating means for storing the pot and heating the cooked rice in the pot. A main body, an openable / closable lid for closing the opening of the rice cooker main body, a pressure valve provided on the lid for adjusting the pressure in the pan, and a pressure valve opening mechanism for forcibly opening the pressure valve And a control device for controlling the heating means and the pressure valve opening mechanism to execute a series of rice cooking processes, and a rice cooking course group including white rice / standard (normal) rice cooking course, white rice / applied rice cooking course A selection means that allows a person to select an arbitrary rice cooking course, and the control device absorbs a predetermined amount of water into the cooked rice in the pan according to the selected rice cooking course, and the absorbed rice cooking Heat the object until it heats to boiling In an electric rice cooker that performs a series of rice cooking steps including an upper heating step, a boiling maintenance step for maintaining the inside of the pan in a boiling state after the completion of the rising heating step, and a steaming step for steaming the cooked rice after the boiling maintenance step When the white rice / application (sushimeshi) rice cooking course is selected by the course selection means, the control device closes the pressure valve and raises and pressurizes the inside of the pan after the water absorption step. The start-up heating process is performed, and after the start-up heating process is completed, the process proceeds to the boiling maintenance process. In the boiling maintenance process, the boiling maintenance power is made larger than the boiling maintenance power of the white rice / standard rice cooking course, The pressure valve is forcibly opened a predetermined number of times, and thereafter has a control means for maintaining the open state and executing the subsequent rice cooking process.

  The invention described in claim 2 is the electric rice cooker according to claim 1, wherein the boiling maintenance power in the boiling maintenance step is white rice / standard rice cooking course in the white rice / application (sushimeshi) rice cooking course. The boiling power is increased in the range of 10 to 30%, and the number of times the pressure valve is opened is one or two times.

  According to a third aspect of the present invention, when the control device opens the pressure valve, the controller lowers the inside of the pan from a pressurized state to near atmospheric pressure at a stroke, and causes a bumping phenomenon in the pan. Control to stir the cooked rice is performed.

  According to the inventions of claims 1 and 2, in the white rice / application (sushimeshi) rice cooking course, the boiling maintenance power is made larger than the boiling maintenance power of the white rice / standard rice cooking course in the boiling maintenance process. Time required for the process is reduced. As a result, the moisture content of the cooked rice is reduced, and excess cooked water can be cooked to make it harder and less sticky. Furthermore, since the number of times the pressure valve is opened is limited to a minimum, excessive twisting does not adhere to the rice grains, and vinegar combination is not hindered.

  According to the invention of claim 3, the pressure valve is forcibly opened in the boiling maintenance step, and the cooked rice in the pan is stirred, so that there is no unevenness in heating, that is, unevenness in cooking rice, and the umami component has a large amount. Rice with good taste is cooked up because it adheres to the rice grains moderately.

It is a front view of the rice cooker which concerns on embodiment of this invention. It is a longitudinal cross-sectional view of the rice cooker of FIG. It is the expanded sectional view which expanded the pressure valve of FIG. 2, and the open mechanism part of this pressure valve. It is a block diagram of the control apparatus which controls a rice cooker. It is an outline block diagram of each rice cooking process of a standard course, a sushi rice course, and a brown rice course. It is a rice cooking process figure of a standard course. It is a rice cooking process figure of a sushi rice course. It is a flowchart figure of the rice cooking process of the standard course of FIG. It is a flowchart figure following the rice cooking process of FIG. It is a flowchart figure of the rice cooking process of the sushi rice course of FIG. It is a flowchart figure following the rice cooking process of FIG. It is a rice cooking process figure of the standard course in the rice cooker of a prior art. It is a rice cooking process figure of the sushi rice course in the rice cooker of a prior art.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the embodiment shown below exemplifies a rice cooker for embodying the technical idea of the present invention, and is not intended to specify the present invention. It is equally applicable to the other embodiments included.

  The rice cooker of the present invention is a pressure-type rice cooker that cooks rice by raising the pressure in the pan to atmospheric pressure or higher, for example, about 1.2 atm during rice cooking, and is particularly characterized by rice cooking control of the sushi rice course. It has become a thing. This rice cooker is suitable as a commercial rice cooker that can cook a large amount of rice, for example, about 33 cups at a time, and can cook a large amount of sushi rice at a time.

  This rice cooker plugs the rice cooker consisting of rice and water, the rice cooker body in which the pot is housed and heating means for heating the cooked rice in the pot, and the opening of the rice cooker body is closed. Controls the lid that can be opened and closed, the pressure valve that is provided on the lid to adjust the pressure in the pan, the pressure valve opening mechanism that forcibly opens the pressure valve during cooking, and the heating means and pressure valve opening mechanism And the control apparatus which performs a series of rice cooking processes, and the rice cooking course selection means which a user can select a rice cooking course are provided. Rice cooking courses are white rice / standard (normal) rice cooking course (hereinafter referred to as standard course), white rice / application (sushi rice) cooking rice course (hereinafter referred to as sushi rice course) and brown rice / standard (normal) rice cooking course (hereinafter referred to as brown rice course). ) Etc. All of these rice cooking courses have a water absorption process in which a predetermined amount of water is absorbed by the rice in the pot, a rising heating process in which the pot is heated and boiled at once after water absorption, and this boiling state is maintained to maintain the rice starch. It is cooked by a series of rice cooking processes including a boiling maintenance process for gelatinizing and cooking, a steaming process for removing extra water from the cooked rice and further promoting gelatinization.

With reference to FIG. 6, FIG. 7, the outline | summary of the rice cooking process of a standard course and a sushi rice course is demonstrated. FIG. 6 is a rice cooking process diagram of the standard course, and FIG. 7 is a rice cooking process chart of the sushi rice course. These rice cooking process diagrams show the temperature change in the pan, the solid line shows the pan bottom temperature curve, and the alternate long and short dash line shows the steam temperature.
(I) Standard course When a standard course is selected by the rice cooking course selection means, the control device executes the following rice cooking process. In addition, the rice cooking control of this standard course is substantially the same as the control of the (■) standard course of the prior art.

  The solid line of FIG. 6 has shown the temperature change in the pan in the rice cooking process of a standard course. In the water absorption process I, the heating means is energized with the pressure valve opened, and the temperature in the pan is set at a predetermined water absorption temperature (40 ° C.) for a predetermined time (20 minutes), and water is absorbed into the rice. To do.

  When this water absorption process is completed, the energization to the heating means is stopped for 40 seconds, the temperature in the pan is stabilized, and the process proceeds to the rising heating process II. In the start-up heating process II, the pressure valve is closed and at the same time the full power is supplied to the heating means to bring the inside of the pan into a pressurized state and a boiling state. The steam temperature sensor installed in the lid or the like detects the steam temperature in the pan, and when this steam temperature reaches a predetermined temperature (75 ° C.), the process proceeds to the next boiling maintenance step III.

  In the boiling maintenance process III, the inside of the pan is maintained in a boiling state with a predetermined boiling maintenance power P1. In the boiling maintaining step III, the pressure valve opening mechanism is operated to forcibly open the pressure valve a plurality of times (four times or more) in a predetermined unit time. In addition, it is preferable that the frequency | count of opening of a pressure valve is changed with the amount of rice cooking. For example, it is preferable to reduce the number of times the pressure valve is opened when the amount of cooked rice is small, and to increase the number of times the pressure valve is opened when the amount of cooked rice is large. Due to the intermittent opening of the pressure valve, the state in the pan is reduced from the pressurized state to the vicinity of the atmospheric pressure at once, and the pressure fluctuation occurs in the pan, and this pressure fluctuation is intermittently repeated a plurality of times. Due to the intermittent opening of the pressure valve, the pressure in the pan fluctuates greatly, and every time a severe boiling phenomenon, so-called bumping phenomenon occurs in the pan, a large amount of foam is generated. The rice grains move to the side in the pan, or the rice grains in the pan are efficiently stirred by repeatedly moving in the opposite direction. By this stirring, sufficient heat is applied to the whole rice grain, and uneven heating is eliminated. In addition, the agitation mixes efficiently with this stirring, and the periphery of the rice grains is coated with this agitation. Since rice balls contain a lot of umami ingredients in rice, the cooked rice becomes delicious when coated with this rice cake. After the pressure valve is forcibly opened several times in the boiling maintenance step III, the remaining boiling maintenance step is continued without performing such a forced opening operation. In the remaining boiling maintenance step, the pressure valve is repeatedly opened and closed in a short time so that a substantially constant pressure state is maintained by the balance between the weight of the ball closing the valve opening and the pressure in the pan.

After the boiling maintaining process is continued for a predetermined time, when a pan bottom sensor installed near the pan bottom detects a predetermined pan bottom temperature (130 ° C.), the control device stops energizing the heating means and proceeds to the steaming step 1. . Note that the pan bottom temperature of 130 ° C. is a temperature at which it is determined that the water in the boiling pan has run out, the forced dry-up is performed, and the dry-up is finished before long (hereinafter, also referred to as a cutting temperature). At this time, the opening operation of the pressure valve is not performed. When this steaming step 1 is completed, the process proceeds to the additional cooking step, and the pressure valve is opened and reheated by the heating means. When this reheating is completed, the process proceeds to the steaming process 2 and the series of rice cooking processes of this standard course is completed. In addition, although the rice cooking process of this standard course is substantially the same as the rice cooking process of the prior art (■) standard course, the water absorption time and the size (4600 W) of the heater used are different.
(B) Sushi rice course When the sushi rice course is selected as the rice cooking course selection means, the control device executes the following rice cooking process.

  The solid line of FIG. 7 has shown the temperature change in the pan in the rice cooking process of a sushi rice course. In addition, the broken line of FIG. 7 has shown the temperature change in the pan in the rice cooking process of a standard course for the comparison with a sushi rice course, and has shown the same thing as the continuous line of FIG. First, in the water absorption step I ′, the heating means is energized with the pressure valve opened, the temperature in the pan is set to a predetermined water absorption temperature (40 ° C.), and this is performed over a predetermined water absorption time (4 minutes). Execute the water absorption process. Since this water absorption time (4 minutes) is shorter than the water absorption time (10 minutes) of the standard course, the water content of the rice is reduced, and it is possible to cook hard rice.

  When this water absorption process is completed, after the energization to the heating means is stopped for 40 seconds, the pan is initially heated with the full heating amount with the pressure valve opened, and the pressure valve is turned on the way. Close and perform the start-up heating step II ′. The steam temperature sensor detects the steam temperature in the pan, and when the steam temperature reaches a predetermined temperature (75 ° C.), the process proceeds to the next boiling maintenance step III ′.

  In this boiling maintenance step III ', the boiling maintenance power P2 is increased by 10 to 30% from the boiling maintenance power P1 of the standard course, and the inside of the pan is maintained in a boiling state. The amount of increase in boiling maintenance power is low when the amount of cooked rice is small and high when the amount of cooked rice is large, depending on the amount of cooked rice. Note that the amount of cooked rice is determined in the rising heating step II 'or the like, and a known method is used as the determination method. By increasing the boiling maintenance power P2 from P1, the time required for the boiling maintenance process III 'is shortened. In FIG. 7, the temperature curve of the sushi rice course reaches the maximum temperature earlier than the temperature curve of the standard course indicated by a broken line, indicating that the boiling maintaining step III 'is shortened. By shortening the boiling maintaining step III ', water absorption of rice is suppressed, and the rice becomes less sticky and hard rice can be obtained.

  In the boiling maintaining step III ', the pressure valve is forcibly and intermittently opened only once for a predetermined unit time. The number of times of opening is not limited to once or twice, but is preferably set to the minimum number. This number of times is determined by the amount of cooked rice and sushi rice conditions. That is, the number of times is increased when the amount of cooked rice is large, and the number of times is decreased when the amount of cooked rice is small. When the number of times of opening is increased, stirring of the cooked rice in the pot becomes intense, and as a result, too much rice sticks to the rice grain, making it difficult to match vinegar.

  The pressure valve is preferably opened at the beginning of the boiling maintenance step III ', that is, immediately after the start-up heating step II' is completed and the process proceeds to the boiling maintenance step III '. If it is made to open at this time, a lot of moisture still remains in the pan, and the cooked rice in the pan can be efficiently stirred using this moisture.

  After the intermittent forced opening of the pressure valve, the pressure valve is kept open and the remaining boiling maintaining step III 'is executed. When this boiling maintenance step III 'is continued and the pan bottom sensor detects a predetermined pan bottom temperature (125 ° C.), the control device stops energizing the heating means and proceeds to the steaming step 1. This pan bottom temperature (cutting temperature) is set lower than the cutting temperature (130 ° C.) of the standard course, making it difficult for rice to be cooked. When the steaming step 1 is completed, the process proceeds to the additional cooking step, the pressure valve is opened, and reheating is performed by the heating means. When this reheating is completed, the process proceeds to the steaming process 2, and thereafter, the process proceeds to the heat retaining process, and the series of rice cooking processes in the sushi rice course is completed.

  In this sushi rice course, in the boiling maintenance process III ', the boiling maintenance power P2 is increased by 10 to 30% as compared with the boiling maintenance power P1 of the standard course, so the time required for the boiling maintenance process III' can be shortened. As a result, the moisture content of the cooked rice is low compared to the cooked rice of the standard course, that is, the excess moisture can be suppressed, and the cooked rice can be hardened and less sticky. In addition, in the boiling maintenance step III ′, the pressure valve is forcibly opened, so that the cooked rice in the pan is agitated and there is no uneven heating, that is, uneven rice cooking, and the umami component rice sticks properly to the rice grains. So, cook it with delicious rice. Furthermore, since the number of times the pressure valve is opened is limited to a minimum, the rice grains do not excessively adhere to the rice grains, and the vinegar combination is not hindered.

  Furthermore, the cutting temperature (125 ° C.) of the sushi rice course is lower than the cutting temperature (130 ° C.) of the standard course. If the cooked rice is cooked, the cooked rice and its surroundings cannot be used as sushi rice. However, since it is difficult to cook rice in the sushi rice course, all cooked rice can be used as sushi rice without waste.

  As explained above, the rice cooker of the present invention is a pressure-type rice cooker, and is particularly characterized in rice cooking control of a sushi rice course. Hereinafter, the concrete structure of this rice cooker, a control apparatus, and rice cooking control by this control apparatus are explained in full detail.

  First, with reference to FIGS. 1-3, the structure of the rice cooker which concerns on embodiment of this invention is demonstrated. 1 is a front view of a rice cooker according to an embodiment of the present invention, FIG. 2 is a longitudinal sectional view of FIG. 1, and FIG. 3 is an enlarged sectional view of the pressure valve of FIG. 2 and an opening mechanism portion of the pressure valve. It is.

  The rice cooker 1 which concerns on embodiment of this invention uses the large-sized pan which can put a large quantity of rice, for example, about 33 cups at a time, and can cook rice, and the pressure in a pan at the time of rice cooking is more than atmospheric pressure, for example, 1.2 atmospheres It is a pressure-type rice cooker suitable for business use in which the pressure is increased to a level. Hereinafter, such a large-sized rice cooker for business use will be described, but the present invention is not limited to such a large-sized rice cooker, and may be 10 cups or less or more. Although a large output heater is used as a large-sized business rice cooker, this heater is also appropriately changed according to the size of the rice cooker.

  As shown in FIG. 2, the rice cooker 1 has a large pot 10 in which rice and water containing rice and water are put, an opening in which the pot 10 is accommodated above, and the pot 10 heated inside to cook rice. A large rice cooker main body (hereinafter simply referred to as “main body”) 2 having a pan bottom heater H1 and a side heater H2 for heating an object, and pivotally supported on one side of the main body 2 to cover the opening of the main body 2 and the pan 10 And a large lid 11 having a lock mechanism 16 for locking in the closed state and a lid heater H3.

  As shown in FIG. 2, the main body 2 includes an outer case 3 and an inner case 4 that is accommodated in the outer case 3 and accommodates the pot 10 therein. The outer case 3 and the inner case 4 A predetermined gap is formed between the control circuit board and the like (not shown) constituting the control device 30 (see FIG. 4). In addition, although not shown, a cooling fan for forcibly cooling the inside of the main body and a motor for driving the cooling fan are accommodated in the gap.

  As shown in FIG. 2, the pan 10 has an opening 10a on the upper side and a bowl-shaped flange portion 10b on the periphery of the opening, and is formed of a large container that can cook a predetermined amount of rice, for example, about 33 cups. Yes. The pan 10 has an inner layer made of a material having high thermal conductivity, such as copper or aluminum, and an outer layer made of a magnetic material, such as stainless steel, and the surface of the inner layer is covered with a fluororesin or the like. ing.

  The main body 2 includes a display operation unit 5 (see FIG. 1) for performing operations such as start of rice cooking, timer reservation, and heat retention, and a pan bottom heater H1, a side heater H2, and a lid in accordance with a rice cooking start signal from the display operation unit 5 A heating circuit comprising a heater H3 and a control circuit board (not shown) for controlling the pressure valve opening mechanism 19 are provided.

  The outer case 3 is formed of a decorative box having a larger outer shape than the inner case 4. The exterior case 3 is provided with an opening 31 above it. Since the outer case 3 accommodates the inner case 4 inside, and a gap is provided between the cases 3 and 4 to dispose the control circuit board and the like, the opening 31 of the outer case is the opening of the inner case 4. It is larger than 41 and its shape is substantially elliptical. In addition, the opening 41 of the inner case is substantially circular like the opening of the pan 10. Further, as shown in FIG. 1, a display operation unit 5 is provided on the front surface of the outer case 3. The display operation unit 5 includes an operation panel 5a provided with various operation keys and a display panel 5b for displaying a setting state set by the operation switches. The operation panel 5a is provided with a start key, a course selection key (rice cooking course selection means), a reservation key, a heat retention key, and the like. On the display panel 5b, rice varieties to be cooked and rice cooking courses such as a standard course, a sushi rice course, a brown rice course, and the like are displayed and can be selected by a course selection key.

  The inner case 4 has a substantially bowl-shaped bottom part 4a having a predetermined diameter, and a cylindrical side wall part 4b erected for a predetermined length from the periphery of the bowl-shaped bottom part 4a. The upper part of 4b opens and it consists of a container of the magnitude | size in which the pan 10 is accommodated from this opening 41, and is formed with the resin molding which has heat resistance. A pot bottom heater H1 made of an electromagnetic induction coil wound in a donut shape is fixed to the bowl-shaped bottom portion 4a by a support (not shown). The pan bottom heater H1 is, for example, 4,600W. Due to this electromagnetic induction coil, an eddy current is generated in the pan 10 and the pan 10 self-heats. The bottom 4a is provided with a pan bottom sensor S1 composed of a thermistor or the like for detecting the pan bottom temperature. By detecting the temperature of the bottom of the pan 10 by the pan bottom sensor S1, the amount of rice cooked in the pan 10 can be determined. Detected. Moreover, the cylindrical side wall part 4b has the attachment part 42 with which the side surface heater H2 is mounted | worn on the inner peripheral wall surface, ie, the inner peripheral wall surface of the side in which the pan 10 is accommodated. The attachment portion 42 is a recess hole that is between the upper opening 41 and the bottom portion 4a and is recessed to a predetermined depth from the inner peripheral wall surface on the side where the pan 10 is accommodated toward the outer peripheral wall surface. A side heater H2 is mounted in the recessed hole.

  As shown in FIG. 2, the openings 31 and 41 of the outer case 3 and the inner case 4 are covered with the frame cover 6 with the frame cover reinforcing member 7 interposed therebetween. The frame cover 6 has an opening that is slightly larger than the opening 10a of the pan 10 inside, and a bowl-shaped periphery that extends outward from the opening and covers the opening 41 of the inner case 4, the outer case 3, and the opening 31. And a substantially oval plate-like body having a predetermined thickness and having a portion, and is formed of a resin molded body. The periphery of the opening on the surface of the frame cover 6 is a placement portion on which the flange portion 10b of the pan 10 is placed. The mounting portion is provided with a locking member 8 that locks the locking mechanism 16 of the lid 11 at one end. The locking member 8 includes a locking piece 8b made of a metal plate to which the locking claw 17a of the locking mechanism 16 is locked, and a base that is positioned above the locking piece 8b and fixes the locking piece 8b. The base 8a, the locking piece 8b, the frame cover 6, and the frame cover reinforcing member 7 are formed with screw holes, which are laminated and screwed. On the base 8a, the flange portion 10b of the pan 10 is placed. The base 8a is formed of a heat resistant resin material. Moreover, the mounting part is provided with a hinge member 9 that pivotally supports the pedestal 8a 'and the lid 11 on which the flange portion 10b of the pan is placed at the same level as the pedestal 8a. The hinge member 9 has a short first mounting portion 9a fixed to the frame cover 6, and a relatively long second mounting portion 9b on which one end of the lid 11 is pivotally supported. It is substantially L-shaped and is formed of a rigid member. This member is formed of a thick metal material, for example, a die-cast molded body made of any of stainless steel, aluminum or aluminum alloy having a thickness of about 2 to 5 mm, and a large and heavy lid. Reinforced to withstand the pressure rise in the pan. Screw holes are formed in the base 8 a ′, the frame cover 6, the frame cover reinforcing member 7, and the first attachment portion 9 a of the hinge member 9, and these are stacked and screwed. On the base 8a ', the flange portion 10b of the pan 10 is placed.

  As shown in FIG. 2, the lid 11 includes an inner lid 12 that closes the opening 10 a of the pan 10, and an outer lid 15 that is positioned above the inner lid 12 and closes the opening of the main body 2. The outer lid 15 is formed with a recess 24 ′ for mounting the storage tank 24, and the periphery is covered with a decorative cover 18. Further, the outer lid 15 is constituted by a solid lid frame.

  As shown in FIGS. 2 and 3, the inner lid 12 is formed of a large disc-shaped lid having a size for closing the large pan opening 10 a, and the pressure valve 13 and the pressure in the pan 10 are abnormal in the upper part. A safety valve V1 and the like are provided for releasing the steam in the pan 10 to the outside when it rises. A seal member that is in contact with the opening 10 a of the pan 10 is attached to the outer periphery of the inner lid 12. Further, a locking member (not shown) is provided on the outer periphery of the inner lid 12 so as to protrude outward and be detachably locked to a fixing means of the outer lid 15. As shown in FIG. 3, the pressure valve 13 includes a valve seat 13a in which a valve hole 131 having a predetermined diameter is formed, a metal ball 14 placed on the valve seat 13a so as to close the valve hole 131, A cover 13b that restricts the movement of the metal ball 14 and holds it on the valve seat 13a. The metal ball 14 has a predetermined weight and closes the valve hole 131 by its own weight. The pressure valve 13 is operated by a pressure valve opening mechanism 19 provided in the outer lid 15. The outer lid 15 is provided with a locking mechanism 16 for the lid 11 at one end, a pressure valve opening mechanism 19 at a location adjacent to the locking mechanism 16, and the outer lid 15 supported by the hinge member 9 at the other end. In addition, a spring pivot mechanism (not shown) that supports the opening operation and holds the opening state is provided. The outer lid 15 is provided with a lid heater H3. Further, a recessed portion 24 ′ to which a storage tank 24 is mounted is provided between the pressure valve opening mechanism 19 and the spring pivot mechanism. As shown in FIG. 2, the lock mechanism 16 has a swing rod 17 that is swingably fixed to the frame of the outer lid 15, and is engaged with the locking member 8 of the main body 2 at one end of the swing rod 17. A locking claw 17a to be stopped and a release button 17b for releasing the locking claw 17a are provided at the other end.

  As shown in FIG. 3, the pressure valve opening mechanism 19 is attached to a cylinder 20 around which an electromagnetic coil is wound, a plunger 21 that moves a metal ball 14 by excitation of the electromagnetic coil, and a tip of the plunger 21. It comprises a spring body and an operating rod 22. The spring body is an extension coil spring. The operating rod 22 is supported by a sealing member 23 having elasticity. The pressure valve opening mechanism 19 operates the pressure valve 13 as follows. As shown in FIG. 2, the pressure valve normally has a valve hole 131 opened because the plunger 21 protrudes and pushes the metal ball 14 by extension of the spring body. When the electromagnetic coil is excited on the basis of a command from the control device 30 (see FIG. 4), the plunger 21 is pulled into the cylinder 20 against the extension force of the spring body, and so far, the operating rod 22 is made of metal. The pushing force that pushed the ball 14 is lost, the metal ball 14 moves sideways due to the inclination of the valve seat 13a, and the valve hole 131 is closed by the weight of the ball itself. Also, in this closed state, when excitation to the electromagnetic coil is stopped, the plunger 21 protrudes again by the extension force of the spring body and pushes the metal ball 14 to open the valve hole 131. Further, a steam sensor S <b> 2 for detecting the steam temperature is attached to the upper part of the pressure valve 13.

  As shown in FIG. 2, the reservoir tank 24 includes a discharge cylinder 24a that discharges steam discharged through the pressure valve 13, an empty chamber 24b that temporarily stores a flavor of umami components, and steam that is externally supplied. A steam return valve V2 is provided at the bottom of the empty chamber 24b to return the stored powder into the pot 10. When the steam is ejected from the pressure valve 13, the rice balls that are umami components are led out from the pot 10 together with the steam through the pressure valve 13, and enter the empty space 24 b of the rice tank 24. Temporarily stored. When the amount of rice stored in the empty chamber 24b reaches a predetermined amount, the rice return valve V2 is opened and returned to the inside of the pan 10. In this container storage tank 24, the discharge cylinder 24 a of the container storage tank 24 is press-fitted and fixed into the mounting hole 15 a provided in the recess 24 ′ of the outer lid 15.

  With reference to FIG. 4, a control apparatus and the rice cooking process by this control apparatus are demonstrated. FIG. 4 is a block diagram of the control device.

  As shown in FIG. 4, the control device 30 includes a CPU that performs various arithmetic processes, a storage unit that includes a ROM and a RAM that store various data, a rice cooking course detection circuit that detects a selected rice cooking course, and a pressure valve 13. A valve opening / closing timer for setting the opening / closing time of the pressure, a counter for counting the number of times the pressure valve 13 is opened / closed, a heating control circuit for controlling the heating temperature and heating time in the pan 10, and a display screen displayed on the display panel 5b And a drive circuit for the pressure valve opening mechanism 19 that controls the opening / closing timing of the pressure valve 13 by driving the pressure valve opening mechanism 19. The storage means stores rice cooking programs corresponding to various rice cooking menus. This rice cooking program performs a water absorption process, a start-up heating process, a boiling maintenance process, a steaming process, an additional cooking process, and a heat retention process after the completion of these rice cooking processes. The heating control circuit is connected to the pan bottom heater H1, the side heater H2, and the lid heater H3, respectively.

  With reference to FIGS. 5-11, control of the rice cooking process of each rice cooking course by this control apparatus is demonstrated.

FIG. 5 shows a rice cooking process of three rice cooking courses, that is, a standard course, a sushi rice course, and a brown rice course. All of these rice cooking courses have a water absorption process in which a predetermined amount of water is absorbed by the rice in the pot, a rising heating process in which the pot is heated and boiled at once after water absorption, and this boiling state is maintained to maintain the rice starch. It is cooked by a series of rice cooking processes including a boiling maintenance process for gelatinizing and cooking, a steaming process for removing extra water from the cooked rice and further promoting gelatinization. The opening control of the pressure valve 13 is performed during the series of rice cooking processes. Further, the user selects the rice cooking course with the course selection key and cooks rice.
(A) Standard course The rice cooking process of a standard course is demonstrated with reference to FIG.5, FIG.6, FIG.8 and FIG. 5 is a schematic block diagram of the rice cooking process in the standard course, the sushi rice course and the brown rice course, FIG. 6 is a cooking process diagram of the standard course, FIG. 8 is a flowchart of the standard course of FIG. 5, and FIG. 9 is the rice cooking process of FIG. It is a flowchart figure following a process.

  First, before starting the rice cooker 1, the cooked rice which consists of a predetermined amount of rice and water in the pot 10 is put. The rice in the pot 10 is white rice. Next, the pan 10 containing the cooked rice is set in the main body 2 and the lid 11 is closed.

  The display operation unit 5 is operated to select a white rice / standard rice cooking course (S1).

  When the rice cooking course is selected (S2) and the white rice / standard course is selected (S29), a high frequency current is applied to the pot bottom heater H1 and the side heater H2, and an eddy current flows between the pot and the pot generates heat. Water and rice are heated (S30). At the same time, the pressure valve 13 is forcibly opened by the pressure valve opening mechanism 19 (S31), and the water absorption step I is executed (S32).

  In the water absorption process I, the water absorption timer starts measuring a predetermined water absorption time (T1 = 10 minutes) (S33), and at the same time, the pot bottom temperature (K1) is measured by the pot bottom sensor (S34). The water absorption time is set to 10 minutes.

  When the pan bottom temperature (K1) reaches 40 ° C. (S35), the heating amount is controlled to continue to measure the preset water absorption time (T1) (S36). When the water absorption time (T1) reaches 10 minutes (S37), the energization to the heating means is stopped for 40 seconds to stabilize the temperature in the pan, and then the whole heating amount (full power) is heated (S38) ( In the start-up heating process II), simultaneously, the pressure valve opening mechanism 19 is operated to pull the operating rod 22 into the cylinder 20, and the metal ball 14 is placed on the valve hole 131 by its own weight to close the valve hole 131, and the inside of the pan The pressure is increased (S39).

  The steam temperature (K2) is measured by the steam sensor S2 (S40). Eventually, when it is detected that the steam temperature (K2) has reached 75 degrees (S41), the process proceeds to the boiling maintenance step III (S42). In the boiling maintaining step, the operation of changing the pressure intermittently by the opening operation of the pressure valve 13 by the pressure valve opening mechanism 19 is performed a plurality of times (S43). In other words, the pressure valve 13 is forcibly opened multiple times, and the pressure in the pan is reduced at a stroke by communicating / blocking the pressurized pan and the atmosphere repeatedly (in this case, the number of times of opening and closing is increased). To increase the stirring effect). Every time the pressure in the pan drops greatly, a bumping phenomenon occurs, foam is generated in the pan, water and rice are stirred, and the rice grains that were in the center move to the side of the pan, and as a result Sufficient heat will be applied to the whole rice grain.

  As soon as the process proceeds to the boiling maintenance step III, the first pressure change operation is performed. This is because immediately after entering the boiling maintenance step III, the amount of residual water in the pot is large, and the larger the amount of residual water is, the easier the rice grains are stirred and moved in the pan. Since the amount of residual water decreases as time passes, the rice grains can be stirred more vigorously by forcibly opening the pressure valve 13 by the pressure valve opening mechanism 19 in the initial stage of boiling maintenance step III where the residual water amount is large. it can. In the second half of the boiling maintenance step III, the amount of residual water in the pan is reduced, and it is difficult for rice to move, so that it is difficult to obtain a large stirring effect even if a bumping phenomenon occurs.

  In this way, by opening and closing the pressure valve several times and stirring the rice grains in the underheated region, the heating state can be averaged, so that the top surface of the cooked rice is finally flattened. be able to.

  This process is HYPERLINK "http://www6.ipdl.inpit.go.jp/Tokujitu/tjitemdrw.ipdl?N0000=231&N0500=4E#M/??;?6;?=?///&N0001=29&N0552=9&N0553 = 000008 "\ t" tjitemdrw "Shown in FIG. The setting of the number of opening and closing of the pressure valve is set in advance by a program (S44). When the amount of cooking rice is large, the number of opening and closing is increased, and when it is small, the number of opening and closing is set small (S45) to (S47). . In this embodiment, when the amount of cooked rice is large, the pressure valve 13 is opened and closed more frequently than when the amount of cooked rice is small, so that averaging by stirring rice grains and prevention of uneven cooking are achieved.

  When the forced opening operation of the pressure valve 13 and the closing operation of the pressure valve 13 due to the weight of the metal ball 14 are repeated a predetermined number of times (S48), the forced opening operation of the pressure valve 13 is not performed thereafter (S48). S49), the pressure valve 13 repeats the opening / closing operation little by little so that a substantially constant pressurized state is maintained by the balance between the weight of the metal ball 14 and the pressure in the pan. Further, the heating amount control in the boiling maintenance process III is continued (S50), and the boiling maintenance process is continued until the pan bottom temperature (K3) detects 130 degrees (S51). When the pan bottom temperature (K3) detects 130 degrees (S52), heating is stopped (S53), and the process proceeds to the steaming step 1.

  In the steaming step 1, the time for the steaming time (T2 = 4 minutes) is started (S54), and the pressure valve 13 is not opened by the pressure valve opening mechanism 19 until the time is 4 minutes.

When the steaming time elapses 4 minutes (S55), the process proceeds to the additional cooking process and the pressure valve opening mechanism 19 forcibly opens the pressure valve 13 (S56), and the reheating time (T3 = 3 minutes). Is started (S57). During the reheating, the valve hole 131 is opened, and the steam in the pan is released from the valve hole 131 to the atmosphere through the steam discharge port 24c. This makes it possible to cook rice deliciously by steaming while removing unnecessary moisture on the surface of the rice grain.In addition, when the lid is opened, the inside of the pan becomes the same as the atmospheric pressure, and the lid can be opened and closed. It becomes easy. When 3 minutes of the reheating time (T3) is finished (S58), the process proceeds to the steaming step 2 to start measuring the steaming time (T4 = 3 minutes) (S59), and when the 6 minutes are finished ( S60), the rice cooking is finished (S61), and the process proceeds to the heat retaining step (S62).
(B) Sushi rice course The rice cooking control of a sushi rice is demonstrated with reference to FIG.5, FIG.7, FIG.10 and FIG. 7 is a rice cooking process diagram of the sushi rice course, FIG. 10 is a flowchart of the rice cooking process of the sushi rice course of FIG. 5, and FIG. 11 is a flowchart following the rice cooking process of FIG.

  In the following flow, the measurement time and temperature settings are the same as those in the standard course unless otherwise explained.

  When white rice / application (sushimeshi) rice cooking course is selected (S63), water and rice are heated (S64) and simultaneously the pressure valve 13 is forcibly opened by the pressure valve opening mechanism 19 (S65). Step I ′ is executed (S66). The water absorption timer starts measuring the water absorption time (T1 = 4 minutes) (S67), and simultaneously measures the temperature at the bottom of the pan (K1) (S68). This sushi rice course cooks rice used for sushi and pilaf. In this case, it is preferable to suppress the water content in the rice grains. Therefore, the water absorption time is shorter than the standard rice cooking course, and is set to 4 minutes, for example. When the pan bottom temperature (K1) reaches 40 degrees (S69), the heating amount is controlled to continue the time measurement of the preset water absorption time (T1) (S70). When the water absorption time (T1) reaches 4 minutes (S71), the energization to the heating means is stopped for 40 seconds to stabilize the temperature in the pan, and then heating is performed with the total heating amount (full power). The process proceeds to II ′ (S72).

  The steam temperature (K2) is measured (S73), and when it is detected that the steam temperature (K2) reaches 75 degrees (S74), the process proceeds to the boiling maintenance step III 'and the heating amount control is continued (S75). The boiling maintenance power in the sushi rice is set to be 10 to 30% larger than the boiling maintenance power in the standard course. Depending on the amount of cooked rice, this set value decreases the amount of increase when the amount of cooked rice is small, and increases the amount of increase when the amount of cooked rice is large.

  In the boiling maintenance step, the pressure valve is forcibly and intermittently opened only once for a predetermined unit time (S76). The number of times of opening is not limited to once or twice, but is preferably set to the minimum number. This number of times is determined by the amount of cooked rice and sushi rice conditions. That is, when the amount of cooked rice is large, the number of times is increased, and when the amount is small, the number is decreased. When the number of times of opening is increased, stirring of the cooked rice in the pot becomes intense, and as a result, too much rice sticks to the rice grain, making it difficult to match vinegar.

  The opening of the pressure valve is preferably performed at the initial stage of the boiling maintenance process, that is, immediately after the start-up heating process is finished and the process proceeds to the boiling maintenance process. If it is made to open at this time, a lot of moisture still remains in the pan, and the cooked rice in the pan can be efficiently stirred using this moisture.

  After the intermittent forced opening of the pressure valve, the heating valve is kept open and the heating amount control is continued (S77).

  When the pan bottom temperature (K3) detects 130 degrees (S78, S79), the heating is stopped (S80), the process proceeds to the steaming step 1, and the steaming time (T2 = 4 minutes) is started (S81). During this time, the pressure valve 13 remains open. When the steaming time elapses 4 minutes (S82), the pressure valve 13 remains in the open operation state (S83), the process proceeds to the additional cooking step, and the reheating time (T3 = 3 minutes) is started (S84). When 3 minutes of reheating time is measured (S85), the process proceeds to the steaming step 2 and the steaming time (T4 = 3 minutes) is measured (S86). When the steaming time of 3 minutes is counted (S87), rice cooking is terminated (S88), and the process proceeds to a heat retaining step (S89).

In this way, in the rice cooking process of the sushi rice course, by suppressing excessive water absorption of rice, the cooked rice can be cooked with low moisture content, hard and less sticky, easy to grip as a sushi, or texture as a pilaf You can get some spicy rice.
(C) Brown rice course With reference to FIG. 5, cooking rice of a brown rice course is demonstrated. When the brown rice / standard (normal) rice cooking course is selected (S3), a water absorption process is executed (S6). This water absorption time is longer than that of white rice, for example, 30 minutes, because brown rice hardly absorbs water.

  If this water absorption time passes, it will transfer to a start-up heating process (S12), and it heats by the total heating amount (full power heating), and simultaneously closes a pressure valve and raises the pressure in a pan (S13). When the inside of the pan boils and the steam sensor detects a predetermined temperature (75 ° C.), the process proceeds to the boiling maintenance step (S16).

  In this boiling maintenance step, the pressure valve 13 repeats the opening / closing operation little by little so as to maintain a substantially constant pressurized state. During this time, sufficient pressure can be applied to absorb moisture in the brown rice.

  When the pan bottom sensor detects a predetermined pan bottom temperature (130 ° C.), the heating is stopped, the process proceeds to the steaming step 1, and the predetermined steaming time is started, and the pressure valve opening mechanism 19 opens the pressure valve 13. The pressure valve 13 is set to the “closed” state (S20).

  After a predetermined time has elapsed, the pressure valve 13 is opened (S22), the heating means is heated again, the process proceeds to the additional cooking step, and the reheating time is started (S23). When the timing of the reheating time is completed, the process proceeds to the steaming step 2 and the timing of the steaming time is started (S25). When the timing is completed, the cooking is terminated and the process proceeds to the heat retaining process (S28).

  As described above, according to the rice cooker of the present embodiment, in the sushi rice course, the boiling maintenance power P2 in the boiling maintenance process III ′ is increased by 10 to 30% compared to the boiling maintenance power P1 of the standard course, so the boiling maintenance is performed. The time required for step III ′ can be shortened. As a result, the moisture content of the cooked rice is lower than that of the cooked rice of the standard course, that is, excess water can be suppressed, the cooked rice can be hardened and less sticky, and rice suitable for vinegar combination can be obtained.

  Moreover, in the boiling maintenance step III ′, the pressure valve is forcibly opened, so that the cooked rice in the pan is stirred and there is no uneven heating, that is, uneven rice cooking, and the umami component of the rice is moderately suitable for the rice grain. Because it adheres, it is cooked into delicious rice. Furthermore, since the number of times the pressure valve is opened is limited to a minimum, excessive twisting does not adhere to the rice grains, and vinegar combination is not hindered.

  Furthermore, since the cutting temperature of the sushi rice course (125 ° C) is lower than the cutting temperature of the standard course (130 ° C), it is difficult to cook in the sushi rice course, and all the cooked rice is used without waste as sushi rice. be able to.

DESCRIPTION OF SYMBOLS 1 ... Rice cooker 2 ... Rice cooker main body 3 ... Exterior case 4 ... Inner case 5 ... Display operation part 6 ... Frame cover 7 ... Frame cover reinforcement member 8 ... Locking member 9 ... Hinge member 10 ... Pan 11 ... Cover 12 ... Inner lid 13 ... Pressure valve 14 ... Metal ball 15 ... Outer lid 16 ... Lock mechanism 17 ... Oscillating rod 18 ... Cosmetic cover 19 ... Pressure valve release mechanism 20 ... Cylinder 21 ... Plunger 22 ... Actuation rod 23 ... Seal member 24 ... Oneba storage tank 30 ... control device

Claims (3)

A pot for containing rice and water rice cooker, a rice cooker main body provided with a heating means for heating the rice cooked in the pot, and an openable lid for closing the opening of the rice cooker main body A body, a pressure valve for adjusting the pressure in the pan provided on the lid, a pressure valve opening mechanism for forcibly opening the pressure valve, and a series of controls by controlling the heating means and the pressure valve opening mechanism A control device that performs the rice cooking process, and a selection means that allows the user to select an arbitrary rice cooking course from a group of rice cooking courses including white rice / standard (normal) rice cooking course, white rice / application (sushimeshi) rice cooking course,
In accordance with the selected rice cooking course, the control device absorbs a predetermined amount of water into the cooked rice in the pan, and the rising heating that heats up the cooked rice cooked and heats up the cooked rice until it boils. In the electric rice cooker that executes a series of rice cooking steps including a step, a boiling maintenance step for maintaining the inside of the pan in a boiling state after the completion of the start-up heating step, and a steaming step for steaming the cooked rice after the boiling maintenance step,
When the white rice / application (sushimeshi) rice cooking course is selected by the course selection means, the control device closes the pressure valve and raises and pressurizes the inside of the pan after the water absorption step. The upper heating step is performed, and after the start-up heating step, the process proceeds to the boiling maintenance step, and in the boiling maintenance step, the boiling maintenance power is made larger than the boiling maintenance power of the white rice / standard rice cooking course, An electric rice cooker comprising control means for forcibly opening the pressure valve a predetermined number of times and then maintaining the open state to execute the subsequent rice cooking process.   In the white rice / application (sushimeshi) rice cooking course, the boiling maintenance power in the boiling maintenance step is increased in the range of 10-30% from the boiling maintenance power in the white rice / standard (normal) rice cooking course, and the pressure valve is opened. The electric rice cooker according to claim 1, wherein the number of times is one or two.   When the pressure valve is opened, the control device lowers the inside of the pan from a pressurized state to near atmospheric pressure at a stretch, and generates a bumping phenomenon in the pan to stir the cooked rice. The electric rice cooker of Claim 1 or 2 characterized by the above-mentioned.

Images