JP2848294B2 - Electric rice cooker - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric rice cooker in which the steam pressure and the amount of released steam are controlled in accordance with a rice cooking process or a heat retaining process.

[0002]

2. Description of the Related Art Generally, rice cooking in an electric rice cooker is performed.
The warming step is, for example, as shown in a rice cooking temperature curve shown in FIG.

(1) Water Absorption Step A large amount of water is required to completely pregelatinize rice starch (to convert α-starch from β-starch, also referred to as gelatinization). To do this, the rice must first be washed and then soaked in water to absorb the water. For example, when rice is immersed in water at 20 ° C., it absorbs about 20 to 30% of the weight of rice in about 2 hours. Since about 2/3 of the water is absorbed in the first 30 minutes, it must be immersed in water for at least 30 minutes.

[0004] However, in the case of an electric rice cooker, it is not possible to maintain an excessively long water absorption time, and quick and quick cooking is required. Therefore, after being immersed in water of about 20 ° C. for a predetermined time, the temperature is raised by heating (performing so-called pre-cooking) to a temperature of about 60 ° C. and maintained at the temperature of about 60 ° C. for a considerable period of time. Kana water absorption is possible.

(2) Cooking Step Next, in order to pregelatinize rice starch, further heating is required. Generally, the temperature for pregelatinizing rice starch is required to be at least 65 ° C. or higher.

Therefore, when rice is actually cooked by an electric rice cooker, an inner pot (cooker) is heated by a rice cooker such as a rice cooker.
Heat it all at once or from the bottom with high heat and heat up to a temperature around 100 ° C.

(3) Boiling maintaining step When the temperature reaches about 100 ° C. as described above, rice starch can be pregelatinized. However, in order to sufficiently pregelatinize starch, the heating time at that temperature is required. Is also relevant.

Therefore, the pregelatinization is promoted by maintaining the above-mentioned boiling state within a predetermined time necessary for sufficiently pregelatinizing rice starch.

(4) Additional Cooking Step By the way, the amount of water in the water absorption step is generally 1.5 times the weight of rice and about 1.2 times the volume ratio. But, of course, the amount of water must be adjusted according to all factors, such as rice origin, brand and whether it is new or old.

[0010] In the cooked rice, when the components of rice, such as "starch" and "protein", are sufficiently bound to water and there is no excess water, it can be said that the water is moderately adjusted. .

[0011] Therefore, it can be said that adjusting the water so that excess water does not remain in the cooked state is a trick of water adjustment, but it is difficult. Therefore, in the case of the old hagama-cooking, a small amount of straw bundle is burned at the end of the rice cooking process from the water absorption to the boiling maintenance process to drive out the extra water, in order to expel this excess water The wisdom of life, such as burning the fox color and adding a delicious scent, is transmitted.

In the case of an electric rice cooker, the amount of heating of the rice heating means is increased for a predetermined period of time, followed by additional cooking and heating, so that excess water is blown off.

(5) Rice steaming step When the additional cooking step is completed, the heating of the rice heating means is stopped, and the rice is dried with residual heat within a predetermined time.

As a result, the starch is pregelatinized up to the rice core.

(6) Insulation step When the rice cooking steps (1) to (5) are completed as described above, the process proceeds to the insulation step at the set insulation temperature after the transition to the set insulation temperature while the heating is stopped. I do.

In the warming step, warming is performed at a set warming temperature by turning on and off warming means such as a warming heater.

In recent electric rice cookers, the heat retention is performed at a low temperature of about 60 ° C. to maintain the deliciousness of the cooked rice for a long time. Intermittent heating control is employed at regular time intervals for sterilization.

In the case of a conventional electric rice cooker, the steam pressure and the amount of released steam in the rice cooking / heating step are generally controlled by opening and closing a steam pressure adjusting valve having a weight structure provided on a lid of the rice cooker main body. When the steam pressure in the inner pot becomes equal to or higher than the set pressure, a predetermined amount of steam is released from the steam release passage in accordance with the pressure increase amount, thereby preventing the spill in the boiling maintaining process and boiling. Pressure adjustment for pregelatinizing rice starch was carried out in the maintenance step and the rice peeling step, and the water content could be adjusted in the additional cooking step.

[0019]

By the way, the temperature curves in the rice cooking process from (1) to (5) shown in FIG. 8 are known from the old days as to how to control the fire, such as "Initially chorochoro (water absorption), This is exactly the case for "medium papa (cooked)", "jujuju" (fired), set a fire (keep boiling), burn a small amount of straw (additional cooking), do not cover even if a baby cry (murashi). If the heating control is properly realized, it is possible to cook sufficiently delicious rice as far as the heat is concerned.

However, in order to cook truly delicious rice, it is necessary to further control the steam pressure in the inner pot, control the amount of steam released from the inner pot to the outside, and prevent spilling over in each cooking step. . In addition, appropriate removal of tsuyu during the heat retaining process is also necessary to prevent white blur and stickiness and finally maintain a delicious heat retaining state of the rice.

For example, in the case of the old rice cooker, corresponding to each of the above-described rice cooking processes, for example, the lid is shifted to prevent spilling over, to remove excess moisture, and to further remove the water from the lid. It has been practiced to increase the pressure in the pot by placing heavy materials such as stones to effectively promote the pregelatinization of rice starch.

In the heat retaining step, rice is transferred to a wooden absorbent sheet having high water absorbency, thereby eliminating the occurrence of tsuyu.
The heat was kept without white bokeh or stickiness.

However, in the case of the present electric rice cooker, even if it has a steam pressure regulating valve as described above, its operation is merely in response to a change in the internal pressure in the inner pan. However, it is not possible to realize the same function as the above-mentioned lid and the fin of the feather pot, and there is a limit to cook delicious rice similar to the feather pot and to realize the same heat retaining performance as the chick.

[0024]

Means for Solving the Problems The inventions of claims 1 to 7 of the present application have been made for the purpose of solving the above-mentioned problems, respectively. It is configured with effective problem solving means.

(1) Invention of Claim 1 Next, the electric rice cooker of the invention of claim 1 of the present application is provided with a passage opening / closing means for opening / closing a steam release passage, and has a rice cooking step and a heat retaining step. The electric rice cooker is provided with a drive unit for opening and driving the passage opening / closing unit, and an operation control unit for operating the drive unit in each of the rice cooking step and the warming step.

Therefore, by the above operation control means,
In each of the rice cooking step and the warming step, when the drive means is operated to open and drive the passage opening / closing means, the appropriate steam pressure, the amount of steam released, and the amount of steam released in accordance with the rice cooking step and the warming step, respectively. It is possible to control the generation amount and keep the temperature.

(2) The invention of claim 2 First, the electric rice cooker of the invention of claim 1 of the present application has a passage opening / closing means for opening / closing a steam release passage, and absorbs water, cooks, keeps boiling, additionally cooks, and cooks. In an electric rice cooker having a rice cooking process consisting of a plurality of processes such as sushi, a driving device for opening and driving the passage opening / closing device, and the driving device in a plurality of predetermined processes in the rice cooking process. And an operation control means for operating.

Therefore, by the above operation control means,
In a plurality of predetermined steps in the rice cooking process including a plurality of steps, such as water absorption, cooking, maintaining boiling, additional cooking, and rice roasting, the driving means is operated to open the passage opening / closing means. By doing so, it becomes possible to appropriately control the vapor pressure and the amount of released steam in accordance with each of the plurality of predetermined processes.

(3) Invention of Claim 3 Next, in the electric rice cooker of the invention of a third aspect of the present invention, in the configuration of the invention of the second aspect, the plurality of predetermined steps are at least boiling. The driving means is operated in an initial stage including a maintenance step.

Therefore, in the initial stage of the boiling maintaining step of the rice cooking step, the operation control means
When the drive means is operated to open the passage opening / closing means to open the steam release passage, a predetermined amount of steam is appropriately discharged to the outside through the opened steam release passage.

(4) Invention of Claim 4 Next, in the electric rice cooker of the invention of the present invention, in the configuration of the invention of the above-mentioned claim 2, at least the plurality of predetermined steps are added at least. In the cooking process, the driving means is operated in the additional cooking process.

Therefore, in the additional cooking step of the rice cooking step, when the drive means is operated by the operation control means to open the passage opening / closing means and the steam release passage is opened, the opened steam is released. The steam can be appropriately released to the outside through the escape passage.

(5) Invention of Claim 5 Next, the electric rice cooker of the invention of claim 5 of the present application is directed to an electric rice cooker having a passage opening / closing means for opening / closing a vapor release passage and having a heat retaining step. A drive means for driving the passage opening / closing means to open, and an operation control means for operating the drive means in accordance with a heat retaining step of a heat retaining step.

Therefore, in the heat retaining step of the heat retaining step, when the drive means is operated by the operation control means to open the passage opening / closing means and open the steam release passage, the opened steam release passage is opened. Through this, the tsuyu, which is likely to occur due to a drop in the temperature of the rice, for example, is appropriately released to the outside in a vapor state.

(6) Invention of Claim 6 Next, in the electric rice cooker of the invention of the present invention, in the configuration of the invention of the above claim 5, the heating step in which the driving means is operated includes an unevenness in the rice cooking process. This is an initial stage in which the process is shifted from the heating process to the heat retaining process.

Therefore, at the initial stage of the heat retention after the end of the washing process in the rice cooking process, the operation control means operates the drive means to open the passage opening / closing means, thereby driving the steam release passage. Is released, the steam is appropriately discharged to the outside through the opened steam release passage.

(7) Invention of Claim 7 Next, in the electric rice cooker of the invention of the present invention, the temperature is maintained by intermittent heating in the heat retaining step. The driving means is intermittently operated in response to the intermittent heating in the heat retaining step.

As described above, when the heat-retaining heating in the heat-retaining step is performed by intermittent heating, the operation control means intermittently operates the driving means corresponding to the intermittent heating in the heat-retaining step. Then, the passage opening / closing means is driven to open in synchronization with the generation of steam due to the intermittent heating, and the steam release passage is opened in an intermittent state, so that the steam is appropriately released from the steam release passage to the outside.

[0039]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration and operation of an electric rice cooker according to an embodiment of the present invention will be described below with reference to the accompanying drawings.

FIGS. 1 and 2 show the structure of the main body of the electric rice cooker.

First, the electric rice cooker according to the present embodiment is configured as a so-called rice cooker type that serves both rice cooking and heat retention. A bottomed cylindrical outer case 1 configured so that an inner pot (rice cooker) 3 can be set therein, and the outer case 1
And a lid unit 2 for covering the upper part of the container.

The outer case 1 includes a bottomed cylindrical cover member 4 made of a synthetic resin, and a synthetic resin shoulder member 5 coupled to the upper end of the cover member 4. Is provided with a bottomed cylindrical inner case (protection frame) 6 for setting the inner pot 3 so that it can be taken out.

The inner case 6 is formed of a bottomed cylindrical thin metal plate, the upper end of which is engaged with the shoulder member 5, and is provided at the center in the vertical direction of the outer peripheral surface of the side wall portion 6a as a heat retaining heating means. Is provided. A center sensor 7 is provided at the center of the bottom wall 6b of the inner case 6 to be in contact with the center of the bottom surface of the inner pot 3.

The center sensor 7 detects the temperature of the inner pot 3,
That is, it functions as a temperature detecting means for detecting the temperature of water and rice in the inner pot 3 and an inner pot detecting means, and detects whether or not the thermistor 8 serving as a temperature detecting unit and the inner pot 3 are set. A sensor unit 7a containing an inner pot set detection sensor and the like is provided.

On the upper surface side of the bottom wall 6b of the inner case 6, a heater plate 9 having a rice cooker MH as a rice cooker is disposed so as to surround the sensor section 7a of the center sensor 7. I have. This heater plate 9
Is tightly adhered to the bottom surface of the inner pot 3 set in the inner case 6 without any gap, and heats the bottom 3a of the inner pot 3 and its outer peripheral surface with good heat conductivity.

On the other hand, the lid unit 2 has an outer cover 10 made of synthetic resin constituting the outer peripheral surface thereof and an inner cover (poly cover) made of synthetic resin constituting an annular frame portion on the inner peripheral surface of the outer cover 10. A hollow structure without an inner cover as shown in the figure is formed by a heat radiating plate 11 which detachably covers an inner opening of the inner cover 11 in the radial direction through a polycover packing 12 having a V-shaped cross section. Have been.
The lid unit 2 is attached to the rear end of the shoulder member 5 via a hinge mechanism 14 so as to be freely rotatable in the vertical direction.
Is provided with a lock mechanism 15 which engages with a predetermined position to maintain the closed state of the lid unit 2.

Reference numeral 16 denotes a steam release passage, reference numeral 20 denotes a passage opening / closing valve as passage opening / closing means which is freely fitted and supported in the vapor release passage 16 so as to be vertically movable, and reference numeral 25 denotes a lid heater as heat radiating plate heating means. . The lid heater 25 is mounted on the upper surface side of the radiator plate 21 with good heat conductivity by covering the upper surface side with a radiator cover.

The steam release passage 16 is formed by forming a portion 10a of the outer cover 10 into a cylindrical body having a different diameter as shown in the figure, and first forming a large-diameter valve body fitting groove 17a on the upper side. Then, a small-diameter cylindrical hole 17b is formed so as to extend downward from the center of the valve body fitting groove 17a.

The lower edge 10b of the cylindrical portion of the outer cover 10 forming the steam release passage 16 is bent radially outward to form a flange, and the flange end 1
8 is bent upward to fix the inner peripheral edge 13a of the heat sink 13 by crimping, and an electromagnet 19 composed of an electromagnetic coil 19a and an iron core (core) 19b is provided above the flange.
Is supported and fixed. The electromagnet 19 is configured as an opening driving means for the passage opening / closing valve 20. The electromagnet 19 is excited when the electromagnetic coil 19a is turned on, that is, when an electric current is applied to the electromagnetic coil 19a. The N pole and the lower end are magnetized to the S pole.

On the other hand, the passage opening / closing valve 20 is composed of a large-diameter valve element 21 and a cylindrical guide part 22, which are formed as described above with the valve element fitting groove 17a and the cylindrical hole. 17b are fitted and supported so as to be freely movable up and down. The valve element portion 21 has a ring-shaped magnet 23 corresponding to the iron core 19b of the electromagnet 19 provided on the inner periphery thereof, and the magnet 23 has a predetermined weight and performs a pressure cone function for pressure setting. On the other hand, the upper end is magnetized to the S pole and the lower end is magnetized to the N pole.

Therefore, as described above, the electromagnetic coil 19
The iron core 19b of the electromagnet 19 corresponding to the ON of a
When the upper end side is magnetized to the N pole (same polarity), the repulsive magnetic force causes the valve body portion 21 from the state in which the steam release passage 16 is completely closed by its own weight in FIG.
The steam release passage 16 of (B) is lifted in an open state. That is, the steam release passage 16 is opened to release the steam and the pressure in the inner pan 3 to the outside.

Reference numeral 24 denotes the above-mentioned steam release passage 16.
An engagement portion provided at a lower end of the guide portion 22 which is loosely fitted with a predetermined passage cross-sectional area (gap) in the portion and serves as an ascent / descent guide for the valve body portion 21, and controls an ascending position. It is. The engaging portion 24 has a locking function of preventing the passage opening / closing valve 20 itself from coming off.
(See FIG. 2A) shows a sufficient clearance distance even in a state where the valve body 21 is raised by turning on the electromagnetic coil 19a and the steam release passage 16 is opened to the outside as shown in FIG. 2B. S ₁ is set to a value of only be ensured.

The opening / closing operation of the passage opening / closing valve 20 by turning on / off the electromagnetic coil 19a is automatically performed by the control of the microcomputer control unit 100, which will be described later, corresponding to the rice cooking / heating step shown in FIGS.

Further, between the inner case 6 and the outer case 1, a control board 29 having a microcomputer control unit 100 for controlling the energization of the rice cooking heater MH, the lid heater 25 and the heat retaining heater SH is accommodated. Have been. On the front end side of the shoulder member 5, an operation panel 30 constituting an operation unit is provided. This operation panel 3
At 0, various switches (menu, heat retention, start, separate cooking, timer, etc.) necessary for rice cooking, a rice cooking menu selected by each of the switches, a switch operation level, and the like are displayed and made visible to the user. And a display unit.

Next, FIG. 3 shows that the passage opening / closing valve 2 is controlled by turning on / off the electromagnetic coil 19a of the electromagnet 19.
The configuration and operation of the passage opening / closing valve control circuit (operation control means) for opening / closing 0 will be described.

First, the above-described electromagnetic coil 19a is connected in series to the secondary side of the power transformer TR via a smoothing circuit composed of a diode D ₁ and a capacitor C ₁ , and via a collector and an emitter of a switching transistor Q. Dropped to ground. The base of the switching transistor Q is connected to the channel opening and closing valve control signal output terminal P ₁ of the microcomputer control unit 100 via a current limiting resistor R ₁ and the base resistor R _2.

On the other hand, reference numeral 41 denotes a constant voltage power supply circuit.
The constant voltage power supply circuit 41 has a diode D ₂
And is connected to the secondary side middle point of the power transformer TR, also the output side to the power supply terminal (+ 5V) P ₂ of the microcomputer control unit 100 via a smoothing circuit composed of the capacitor C _2.

Reference numeral 42 denotes the power transformer TR.
Is an AC power supply (100V) connected to the primary side.

For example, as shown in the flowchart of FIG. 4, the microcomputer control unit 100 specifically determines the status and stage of each step of the rice cooking or warming step during or after rice cooking using time, temperature, and the like as parameters. Then, in accordance with the determination result, the O of the electromagnetic coil 19a is set in accordance with each stage of the rice cooking / heating process as shown in the time chart of FIG.
It outputs N (H) and OFF (L) signals.

When the electromagnetic coil ON signal (H) is output, the switching transistor Q is turned ON, and a current flows through the electromagnetic coil 19a. FIG.
From the lowering (closed) state due to its own weight in (A), it is lifted upward as shown in FIG. 2 (B) to open the steam release passage 16.
As a result, the steam in the inner pot 3 is released to the outside, and the pressure is reduced.

On the other hand, when the electromagnetic coil ON signal (H) is cut off and becomes the OFF signal (L) state, the iron core 19b of the electromagnet 19 is demagnetized, so that the valve body 21 of the passage opening / closing valve 20 has its own weight. Thereby, the steam release passage 16 shown in FIG. 2A is returned to a completely closed state. The own weight of the passage opening / closing valve 20 is
The weight of the magnet 23 is considerably heavy, and the pressure in the inner pan 3 can be maintained at a considerably high level when the steam release passage 16 is closed.

Next, the flowchart of FIG. 4 shows the specific contents of the opening / closing control of the passage opening / closing valve 20 by the microcomputer control unit 100.

The content of the control is described as a rice cooking process (consisting of a plurality of processes of water absorption, cooking, maintaining boiling, additional cooking, and steaming).
5 to the heat retention process (which includes an initial stage of reaching the target heat retention temperature after completion of the rice cooking process unevenness process and a heat retention stage by intermittent heating near the target heat retention temperature). I do.

That is, first, the rice cooker start switch O
The control is started by N, and various data such as sensor data is read first (step S ₁ ). Then, it is determined whether or not the inner pot 3 is actually set from the data of the inner pot set detection sensor (step S ₂ ).

As a result, when the determination is YES, the water absorption heating is started for the first time, and after maintaining the water temperature at 20 ° C. for a predetermined time,
By further increasing the heating amount and maintaining the water temperature at 60 ° C. for a predetermined time, the rice is sufficiently absorbed by water (step S ₃ ). At the same time, in the water absorption step, the electromagnetic coil 19a is used.
Is kept OFF to prevent the steam and the temperature from escaping (step S ₄ ).

The water absorption step is performed within a predetermined time ta set in advance.

Next, the end of the water absorption step is determined using the elapse of the set time ta as a determination parameter (step S ₅ ).
When it is determined that the water absorption time ta has elapsed and the water absorption process has been completed (YES), the rice cooker MH and the heat retaining heater SH each start heating at full power and heat up to about 100 ° C. at a stretch over a high heat ( Along with step S ₆ ), the OFF state of the electromagnetic coil 19 a is also maintained (step S ₇ ) to efficiently heat the steam and the temperature without escaping.

Thus, the pregelatinization of the starch of the rice which has been sufficiently absorbed in the water absorption step is started.

When the temperature of the water in the inner pot 3 reaches 100 ° C., the end of the cooking step is determined based on the output of the thermistor using the reaching of 100 ° C. as a determination parameter (step S ₈ ). .

As a result, if it is determined to be YES (end), subsequently, the heating amount is slightly reduced to maintain the boiling state at the water temperature of 100 ° C. within a predetermined time tb. Predetermined set time t at the same time as the maintenance process
And a ₁ in the electromagnetic coil 19a is turned ON to open driving the channel opening and closing valve 20 opens the vapor release path 16 to the outside as in the case where ajar lid old Hagama as shown in FIG. 2 (B) (Steps S ₉ and S ₁₀ ).

As a result, a sufficient boiling state is maintained while the generation of steam and squid that is about to start to spill is suppressed at a good timing.

Next, it is determined whether the set time t ₁ has elapsed (step S ₁₁ ). If YES (t _{1 has} elapsed),
Figure by an electromagnetic coil 19a to OFF (step S ₁₂₎ 2
As shown in (A), the steam release passage 16 is completely closed, and the steam pressure in the inner pot 3 is sufficiently increased in the same manner as in the case where the lid of the old pot is weighed to reduce the pregelatinization of rice starch. Promote as efficiently as possible.

Then, the elapse of the above-mentioned boiling maintenance time tb is determined (step S ₁₃ ). If the determination is YES after the elapse of the boiling maintenance time tb, the heating amount of the rice cooking heater MH is further increased slightly to make an advance. One of the predetermined processes is to start heating after heating, and the electromagnetic coil 19a is turned on.
N to open the passage opening / closing valve 20 for a predetermined time t ₂
Opening the inner steam escape passage 16 (step S _14,
S _15).

As a result, the excess water content in the inner pot 3 is blown off, and the water content around each rice grain becomes uniform and appropriate.

Then, the O of the electromagnetic coil 19a is
The elapse of the N set time t ₂ is determined (step S ₁₆ ), and when the set time t ₂ elapses, the electromagnetic coil 19a is turned off once.
A manner (step S _17), the OFF state for a predetermined time t ₃
After inner maintained, when the time t ₃ is determined that the elapsed (YES in step S _18), the channel opening and closing valve 20 and opening operation by an electromagnetic coil 19a to a predetermined set time t ₂ in ON again, permit vapors to escape by opening the vapor release path 16 by the same purpose (step S _19).

[0076] Then, the ON set time t ₂ has passed (YES at step S ₂₀₎ Then, again the electromagnetic coil 19a O
In the FF close the steam release passage 16 (step S _21).

In this manner, the adjustment of the water content in a necessary and sufficient range is appropriately performed.

Finally, the set time t of the additional cooking process
c is determined (step S ₂₂₎ that has passed, YES
If it is determined, stop heating by the left cooking heater MH continued to OFF of the electromagnetic coil 19a is turned OFF (step S _23), a predetermined set time td Nomura said utilizing residual heat only performed with.

As described above, the pressure in the inner pan 3 is sufficiently increased by executing the swashing process in the swashing process while the steam release passage 16 is completely closed by turning off the electromagnetic coil 19a. The action is synergistic and the pregelatinization of the rice core progresses sufficiently.

[0080] Eventually to the steaming the set time td elapses step (YES in Step S _24), if the steaming process is completed, into the subsequently incubating process.

At the time of the transition to the heat retaining step, a relatively large amount of wood is likely to be generated around the inner pot as the temperature of the inner pot 3 and the rice decreases. And that causes white blur and stickiness of the rice. In addition, this tendency is more remarkable when the target temperature is as low as 60 ° C. and the temperature is low.

[0082] Therefore, as described above As a countermeasure, with the lapse of set time td, it is determined steaming the end of step (becomes YES at step S _24), when entering the insulation process, the insulation slightly in synchronization with the transition to step to a longer predetermined time t ₄ in the electromagnetic coil 19a is turned oN to open driving the channel opening and closing valve 20, and opening the vapor release path 16, remains in the steaming step the steam in Uchinabe 3 have to pre Ji fit fully released (step S _25).

By doing in this way, the occurrence of squeeze due to a subsequent decrease in temperature is suppressed as much as possible.

[0084] When the ON setting time t ₄ of the electromagnetic coil 19a has elapsed (YES in step S _26), set retained temperature targeted by the electromagnetic coil 19a to OFF 6
Wait for the temperature to drop to 0 ° C. (step S ₂₇ ).

Next, temperature data based on the output of the thermistor is read (step S ₂₈ ), and it is determined whether or not the temperature of the rice has dropped to the target set temperature of 60 ° C. (step S ₂₉ ). ℃ if YES it is determined that the decrease in the performs intermittent heating at a predetermined period (step S _30),
Simultaneously sterilizing the putrefactive bacteria, it corresponds ON the predetermined short time t ₅ in the electromagnetic coil 19a relief vapor passage 1
6 was opened, control the constant humidity of the inner pot 3 to the optimum humidity level causing no soup by releasing it to a vapor occurring intermittently (step S _31).

[0086] Thereby, a good heat retaining performance having the same hygroscopicity as that of the old ohitsu is realized.

Then, while performing the intermittent heating and the intermittent humidity control, the heat retention control is executed within a long set time te of, for example, about 12 to 24 hours. When There is determined (YES at step S _32), and ends all the control in the OFF warmth heater SH, etc. (end).

The following changes and improvements that make the points of the present invention more effective are arbitrarily adopted as necessary to the configuration of each unit in the above embodiment. These are all included in the embodiment of the present invention.

(1) Instead of an electric rice cooker having a heat retaining function (a so-called rice cooker), an electric rice cooker having no heat retaining function is used, and a control program for the above rice cooking process alone is applied. In addition, a control program for only the heat retaining step is applied instead of the electric rice cooker instead of the heat retaining container.

(2) The rice cooking heater MH as the inner pan heating means is changed to a work coil (so-called IH type).

(3) A reversible rotating motor is used in place of the electromagnet 19, the valve body 21 is supported by the screw shaft so as to be relatively movable in the vertical direction, and the rotation direction of the screw shaft is changed by the motor. Thus, the valve body 21 is moved up and down to open and close the steam release passage 16.

(4) As shown in FIG. 6, a piston type motor 30 is employed in place of the electromagnet 19, and the piston rod 31 is moved up and down by forward and reverse rotation of the motor 30 so that the valve body 21 of the passage opening / closing valve 20 is moved. To open and close. Motor 3
Reference numeral 0 denotes a mechanism (rack and rack) that is supported in a support housing 32 provided on an inner cover (or heat radiating plate) 40 of the lid unit 2 and converts the forward / reverse rotation of the motor 30 into a vertically moving operation. The piston rod 31 is moved up and down via a pinion or other mechanism. The piston rod 31 supports a support portion 34 at the lower center position of the valve body portion 21,
The valve body 21 is moved up and down as shown by the arrow by the elevation, and the steam release passage 16 is opened and closed in the same manner as in the first embodiment. Reference numeral 33 denotes a cylindrical body that performs a guiding function when the valve body 21 moves up and down.

(5) As shown in FIG.
Is supported by a coil spring 37 made of a shape memory alloy that can be electrically deformed through a cap 36, and the heating coil 3
By changing the energization state such as the current application state to the coil 8, the temperature is changed, and the coil spring 37 made of a shape memory alloy is deformed and expanded, and the valve body 21 is moved up and down to open and close the vapor release passage 16. .

In this case, an electric current may be supplied to the coil spring 37 itself to generate heat.

(6) The valve body 21 is returned to the passage closing direction not by its own weight but by the biasing force of a coil spring or the like.

(7) By changing the direction of the current applied to the electromagnetic coil 19a, the magnet 23 is repelled or attracted to move the valve body 21 up and down, thereby opening and closing the steam release passage 16.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a structure of a main body of an electric rice cooker according to an embodiment of the present invention.

FIG. 2 is an enlarged sectional view showing different operation states of the main part of the electric rice cooker main body in correspondence with each other.

FIG. 3 is an electric circuit diagram of a main part of the electric rice cooker.

FIG. 4 is a flowchart showing control contents of a microcomputer control unit of the electric rice cooker.

FIG. 5 is a time chart showing control contents of a microcomputer control unit of the electric rice cooker.

FIG. 6 is a sectional view of a main part of an electric rice cooker according to another embodiment of the present invention.

FIG. 7 is a sectional view of a main part of an electric rice cooker according to another embodiment of the present invention.

FIG. 8 is a temperature curve of a conventional rice cooker / heat keeping process of a general electric rice cooker.

[Explanation of symbols]

2 is a lid unit, 3 is an inner pot, 7 is a center sensor, 9 is a heater plate, 16 is a steam release passage, 19 is an electromagnet,
19a is an electromagnetic coil, 19b is an iron core, 20 is a passage opening / closing valve, 23 is a magnet, 100 is a microcomputer control unit, and MH is a rice cooking heater.

Claims (7)

(57) [Claims] 1. A passage opening / closing means for opening / closing a steam release passage.
Electric cooking comprising a rice cooking step and a heat retaining step
Driving means for opening the passage opening / closing means in the rice cooker
And the driving means for each of the rice cooking process and the heat retaining process.
Operation control means for operating the
Electric rice cooker. 2. A steam opening / closing means for opening / closing a steam release passage , and water absorption, cooking, maintaining boiling, additional cooking, and unevenness.
In electric cooker comprising a plurality of made of step cooking process, such as by a driving means for driving for opening the passage opening and closing means, said driving means defined pre Ji fit in the cooking process
Electric rice cookers, characterized in that a and operation control means for Ru is operated in a plurality of steps were. 3. The method according to claim 1, wherein a plurality of predetermined steps are reduced.
Both include a boiling-preserving process, in its initial stage, electric cooker according to claim 2, wherein the driving <br/> hand stage is characterized that it is so that the operation. 4. The method according to claim 1, wherein a plurality of predetermined steps are reduced.
Both include add cooking process, in the add cooking step, electric cooker according to claim 2, wherein the drive means is characterized that it is so that the operation. 5. comprises a channel opening and closing means for opening and closing the steam escape passage, and in an electric rice cooker comprising a heat insulating step, driving means for driving for opening the passage opening and closing means, the driving means of the incubating process electric rice cookers, characterized in that a and operation control means for Ru is operated in accordance with the thermal insulation stage. 6. A heat insulating step of driving means is actuated, electric cooker according to claim 5, wherein the initial stage der Rukoto migrated from step steaming in cooking process incubating process. 7. In the heat keeping step , heat is kept by intermittent heating.
Has become as I will, drive means, you in the incubating process
Kicking electric cooker according to claim 5, wherein that it is so that the actuated intermittent in response to the intermittent heating.