JPH05228050A - Rice boiler - Google Patents

Abstract

PURPOSE:To let a user know that boiled rice is at a suitable temperature for eating without directly eating the boiled rice in a container. CONSTITUTION:After rice boiling operation by a rice boiling controller 1, a hot-keeping controller 52 controls the power supply to side and cover hot- keeping heaters 11 and 12 so that the boiled rice in a container is kept at 73 deg.C. When a heating controller 53 is selected at this time, the boiled rice is heated up to 90 deg.C. When a temperature sensor 13 detects the fact that the boiled rice is at 80 deg.C or higher during hot-keeping action, a hot mode indicator 27 is turned on to show that the boiled rice is at a suitable temperature for eating.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rice cooker, and more particularly to a rice cooker that performs a heat retaining operation.

[0002]

2. Description of the Related Art Generally, a rice cooker is disclosed in, for example, JP-A-3-63.
As disclosed in No. 015 etc., rice, which is rice to be cooked, and water are contained in a container, and the container is heated by energization of a rice cooking heater provided on the inner bottom portion of the main body to cook rice. Then, when the temperature sensed by the temperature sensor that detects the temperature of the container reaches the predetermined cooking temperature, the rice cooking heater is turned off and the rice cooking is completed through the unevenness stroke, and then the temperature sensed by the temperature sensor keeps the predetermined temperature. When the temperature drops to the temperature, the warming heaters provided on the inside and lid of the bowl are turned off to heat the container to keep the cooked rice at a constant warming temperature. ..

According to JIS, the optimum rice temperature during the heat retaining operation is determined to be about 70 ° C. This is because, in the range of 20 to 60 ° C, which is the normal temperature of the rice, the rice rots due to various bacteria contained in the atmosphere in a short time, and the low temperature makes it unsuitable for the taste. Is maintained at a high temperature of 70 ° C or higher, the so-called Maillard reaction between sugar and amino acid causes yellowing,
This is because the odor is generated due to the oxidation of fatty acids.

[0004]

In the rice cooker according to the above-mentioned prior art, the rice temperature during the heat retaining operation is from 67 ° C to 76 ° C.
It is known that, although the temperature is kept in the range of 0 ° C, the most preferred taste of rice is about 85 ° C or higher at which the texture of freshly cooked food can be obtained. For this reason, it is considered to heat the container while keeping it warm to raise the rice temperature temporarily, but the rice temperature is about 85 ° C or higher even after the rice is cooked immediately after the rice cooking operation. There was a problem in that it was necessary to open the lid and eat the rice directly in order to know whether the temperature was suitable for.

Therefore, the present invention solves the above problems and provides a rice cooker capable of knowing that the temperature of the rice is at a temperature suitable for the taste without directly eating the rice in the container. With the goal.

[0006]

The present invention relates to a container for containing cooked food, a heating means for heating the container, a temperature detecting means for detecting the temperature of the container, and a temperature detected by the temperature detecting means. Rice cooking control means for controlling rice cooking operation based on
A warming control means for keeping the cooked food at about 67 ° C. to 78 ° C. after the rice cooking operation, a heating control means for heating the cooked rice kept at this predetermined temperature to about 80 ° C. to 95 ° C., After the rice cooking operation, a display means is provided for displaying the fact that the rice to be cooked is at 80 ° C. or higher.

[0007]

With the above construction, by selecting the heating control means, it is possible to heat the cooked food kept at about 67 ° C to 78 ° C to about 80 ° C to 95 ° C by the heating means. Also, when the temperature detecting means detects that the temperature of the cooked rice is 80 ° C. or higher immediately after the rice cooking operation or by the selection of the heating control means, the display means informs the user of the fact. Close.

[0008]

EXAMPLE An example of the rice cooker of the present invention will be described below with reference to FIGS. In FIG. 2, which is a cross-sectional view of the rice cooker, 1 is rice, which is a rice to be cooked, and 2 is water.
Reference numeral 3 denotes a container body whose upper surface is opened, and the container body 3 includes an inner case 4 and a plastic outer case 5. A container 6 having an open upper surface is housed in the inner case 4 so as to be freely inserted and removed. Reference numeral 7 denotes a lid, and the lid 7 has a hollow outer lid 8 that openably covers the upper opening of the container body 3, and an open upper opening of the container 6 provided below the outer lid 8. And an inner lid 9 that covers Further, a rice cooking heater 10 that heats the container 6 from below during rice cooking is provided at the bottom of the inner case 4. Furthermore, inner case 4
A side heat retention heater 11 that heats the container 6 from the side is provided on the outer side surface around, and a lid heat retention heater 12 that heats the lid body 7 is provided at the lowermost part of the outer lid 8. The heaters 10, 11 and 12 constitute heating means.
13 is a temperature sensor that is arranged at the bottom of the inner case 4 and includes a thermistor that detects the temperature of the container 6,
The temperature sensor 13 is provided via a heat sensitive plate 14 so as to come into pressure contact with the lower surface of the container 6. Also, 15 is the outer case 5
It is an electronic circuit unit provided inside.

FIG. 3 shows a display unit 21 and an operation unit 22. The display unit 21 includes a current time display unit 23 for the current time, which is composed of a 4-digit 7-segment LCD, and the cooking time. A cooking time display unit 24 for displaying is provided. Further, the display unit 21 has mode display units 25, 26, 27 and 28 consisting of four LEDs, 25 for cooking rice, 26 for keeping warm, 27 for hot display, 28 for timer. Yes, the mode being processed is displayed. Operation part
22 has a plurality of switches, and a rice cooking switch 29,
It has a heat retention switch 30, a hot switch 31, a current time setting clock switch 32, a timer switch barrel forward switch 33 and a back switch 34, a timer rice switch 35, and a cancel switch 36 for cancellation. ..

Next, the structure of the electric circuit will be described with reference to FIG. In the figure, 41 is a commercial AC power supply of 100V, and a transformer 42 is connected to this AC power supply 41,
42 is connected to a microcomputer 44 with a built-in A / D converter via a constant voltage circuit 43. Thus, the microcomputer 44 is supplied with the 5V DC power supply. In addition, between the two poles of the AC power supply 41, the rice cooking heater 10
And a relay 45 contact point 45A are connected in series, and the side heat retention heater 11 and the lid heat retention heater 12 are connected.
A series circuit of a parallel circuit and a triac 46 is connected. The coil 45B of the relay 45 is a relay drive circuit.
The gate of the triac 46 is connected to the microcomputer 44 via the triac drive circuit 48 while being connected to the microcomputer 44 via the 47. Therefore, the contact signal 45A is closed and the rice cooking heater 10 is energized only when the coil 45B is energized via the relay drive circuit 47 by the output signal from the microcomputer 44, and the signal from the microcomputer 44
Side insulation heater only when TRIAC 46 is energized
11 and the lid heat retaining heater 12 are energized. The power consumption of the rice cooking heater 10 is 650 W, the power consumption of the side heat retaining heater 11 is 50 W, and the power consumption of the lid heat retaining heater 12 is 2 W.
It is 0W. Further, the rice cooker switch 29, the off switch 36, and the like are connected to the microcomputer 44, and a buzzer 49, which is a notification means, is connected through a buzzer drive circuit 50.

As shown in FIG. 1, the microcomputer 44 has a software function to control the heaters 10, 11 and 12 by using the temperature sensor.
The rice cooking control means 51 for controlling the rice cooking operation based on the sensed temperature from 13, the heat retention control means 52 for keeping the rice 1 in the container 6 at 73 ° C. after the rice cooking operation by the rice cooking control means 51, and the hot switch 31 Insulated rice that operates by operation 1
It has a control means 54 provided with a heating control means 53 for heating up to 90 ° C. Further, the hot-spot mode display section 27 is in a blinking state when the heating control means 53 is in operation by the hot-switch switch 31, while the temperature sensor indicates that the temperature of the rice 1 is 80 ° C. or higher after the rice is cooked.
When it is detected by 13, it is controlled to be in a lighting state. Further, the storage means 55 stores whether or not the hot switch 31 has been pressed, and when the hot switch 31 is pressed again when the heating control means 53 has already been operated,
The operation of the hot switch 31 is invalidated through the control means 54, and the buzzer 49 notifies that effect.
The control means 54 also has a function of timer reservation control means for starting the rice cooking operation before the set time of the cooked rice reserved time set by the timer rice switch 35.

Next, the operation of the above configuration will be described. First, the operation of the circuit will be described with reference to FIG.
By pressing the rice cooking switch 29, the mode display for rice cooking
25 is turned on, and the rice cooking operation by the rice cooking control means 51 is started. During this rice cooking operation, the rice cooker heater 10 is turned on and off by controlling the opening and closing of the relay 45, and the triac 46 is controlled to be turned on and off, and the side warmer heater 11 and the lid warmer heater 12 are shut off and heated. Done. On the other hand, at the time of the heat retention operation after the completion of rice cooking, the mode display section 25 for rice cooking
Is turned off, and the heat retention mode display portion 26 is turned on. At this time, the relay 35 is normally open, and the side heat retention heater 11
And, only the lid warming heater 12 is turned on and off to perform heating. Further, during the heat retaining operation, when the hot switch 31 is operated when the inside of the container 6 has a predetermined heat retaining temperature,
The hot mode display 27 flashes and the relay
By the open / close control of 45 and the on / off control of the triac 46, the heaters 10, 11 and 12 are turned on and off to perform heating. When the heat retention switch 30 is pressed, the rice cooking operation is not performed, and only the heat retention operation is performed. Further, when the off switch 36 is pressed during both the rice cooking and the heat retention, the operation is forcibly stopped. ..

Next, details of the operation will be described with reference to FIG. The graph shown in FIG. 5 shows the time-dependent change in the temperature sensed by the temperature sensor 13, and the lower two graphs show the timings at which the heaters 10, 11 and 12 are turned on and off. At the beginning of rice cooking, the hot water cooking operation is first performed for 8 minutes. During the hot water cooking operation, first, only the rice cooking heater 10 is energized to heat the container 6, and then all the heaters 10, 11 and 12 are cut off for 5 minutes. The main rice cooking operation is performed subsequent to the hot water cooking operation. The rice cooking heater 10 is continuously energized from the start of the main rice cooking operation, but when the container 6 boils thereafter, the rice cooking heater 10
Repeats energization and disconnection at intervals of 30 seconds. On the other hand, during the main rice cooking operation, the side heat retaining heater 11 and the lid heat retaining heater 12 are continuously energized. The microcomputer 44 is
The boiling point is determined based on the temperature sensed by the temperature sensor 13. Then, when the temperature sensed by the temperature sensor 13 reaches 120 ° C. while the rice cooking heater 10 is intermittently energized, after that, the operation shifts to the wiping operation. During the wiping operation, the side warming heater 11 and the lid warming heater 12 are continuously energized, and the rice cooking heater 10 is cut off.
After a lapse of minutes, the rice cooking heater is energized for only 30 seconds
It is cooked and heated. This purging operation is performed for 15 minutes, and then the warming operation is started. During the heat retention operation, the rice cooking heater 10 is always in a power-off state, but the side heat-retaining heater 11 and the lid heat-retaining heater 12 are controlled to switch on and off to heat the container 6. That is, at the start of heat retention, all heaters
If 10, 11, 12 are cut off, and then the temperature sensed by the temperature sensor 13 is less than 73 ° C, the side warmer heater 11 and the lid warmer heater 12 are energized, while the temperature sensor 13 If the sensed temperature is above 73 ° C,
The heaters 11 and 12 are cut off, and the rice temperature in the container 6 is controlled to be maintained at a predetermined temperature.

Next, the details of each operation after the rice cooking operation will be described with reference to the graph shown in FIG. In addition, in FIG. 6, the graph shows the temperature sensor as in FIG.
Change in temperature sensed by 13 and each heater 10,
It shows the timing of disconnection of 11 and 12, and further,
The display states of the heat retention mode display section 26 and the hot mode display section 27 at the time of each operation are shown on the upper side. When the wiping operation is completed by a series of rice cooking operations by the rice cooking control means 51, the warming control means 52 then shifts to the warming operation, and the warming mode display section 26 is turned on. At this time, all the heaters 10, 11 and 12 are cut off and the temperature sensed by the temperature sensor 13, that is, the rice temperature in the container 6 decreases, but at the start of the heat retaining operation, the rice temperature is 80 ° C or higher. The temperature is suitable for the taste, and this rice temperature is 80 ° C.
During the time A, which is the above, the hot mode display unit 27 that indicates when to eat is lit, and then the rice temperature is 80 ° C.
When the temperature is lowered below, the hot mode display unit 27 is turned off, and the heat retention control means 52 controls the side heat retention heater 11 and the lid heat retention heater 12 so that the rice temperature is maintained at 73 ° C. Next, when the hot switch 31 is pressed in this state, the hot mode display unit 27 causes the heating control means 53.
A blinking display indicating that the operation of is being performed. The heating control means 53 energizes and heats the side warming heater 11 and the lid warming heater 12 until the rice temperature reaches 90 ° C., and the rice cooking heater 10 is turned on and off at intervals of 30 seconds to strengthen. In order to prevent charring of the rice 1 in the container 6, after heating, the rice cooking heater 10 is energized for 10 seconds and then cut for 60 seconds to repeat the pattern, thereby heating the bottom of the container 6 weakly.
In this way, when the rice temperature is heated to 80 ° C or higher again, the hot mode display unit 27 performs continuous lighting display indicating the eating condition during the time A when the rice temperature is 80 ° C or higher, and then the rice temperature is changed. When the temperature sensor 13 detects that the temperature has reached 90 ° C, the rice cooking heater 10 is turned off, and the side heat retention heater 11 and the lid heat retention heater 12 are turned off to reduce the rice temperature to 9
Keep at 0 ° C. Then, after a lapse of a predetermined time, for example, 10 minutes, the side heat retaining heater 11 and the lid heat retaining heater 12
The power is cut off to forcibly stop heating, and the temperature control means 52 shifts to normal temperature control. At this time, when the rice temperature drops to 80 ° C. or lower, the hot mode display unit 27
Turns off again.

FIG. 7 is a flow chart showing each operation during heat retention. When shifting to the heat retention operation, the heat retention control means 52 turns off the rice cooking heater 10 and, if the temperature T sensed by the temperature sensor 13 is T ≧ 73 ° C., the side heat retention heater.
11 and lid insulation heater 12 are turned off, while T <73
If it is ℃, the side heat insulation heater 11 and the lid heat insulation heater 12
To keep the rice temperature at 73 ° C. (step 1).
At this time, it is determined in step 2 whether the temperature T sensed by the temperature sensor 13 is 80 ° C. or higher, and T ≧ 80.
If the temperature is ° C, the LEDs of the heat retention mode display section 26 and the hot mode display section 27 are lit (step 3), and the process proceeds to step 4 to determine whether or not the hot switch 31 is pressed. If the hot switch 31 is pressed, the rice in the container 6 is already ready to be eaten,
While disabling the operation of this hot switch 31,
The buzzer 49 notifies to that effect (step 5), and the process proceeds to step 1 again. If the hot switch 31 is not pressed in step 4, the process directly goes to step 1 to continue the on / off control of the heaters 10, 11 and 12. On the other hand, according to the determination in step 2, T <8
If it is 0 ° C, the LED of the heat retention mode display section 26 lights up,
The LED of the hot-mode display unit 27 is turned off (step 6), the process proceeds to step 7, and it is determined whether or not the hot-switch 31 is pressed. Then, if the hot switch 31 is not pressed, the process directly proceeds to step 1, while if the hot switch 31 is pressed, the process proceeds to step 8 and based on the contents stored in the storage means 55, the hot-warm hot It is determined whether the number of times the switch 31 is pressed is the first time. At this time, if the number of times of pressing is the first time, the process proceeds to step 9, and the heating control means 53 turns on and off the rice cooking heater 10 at intervals of 30 seconds, then turns on the power for 10 seconds and turns off for 60 seconds. Repeat and T ≧ 9
If it is 0 ° C, the side heater 11 and the lid heater
Turn off 12, while if T <73 ℃, side heat insulation heater
11 and the lid heat retaining heater 12 are energized to perform heating.
At the same time, the LED of the heat retention mode display section 26 is turned on and the LED of the hot mode display section 27 is blinked, thereby displaying that heating is in progress.
Then, in step 10, it is determined whether the sensed temperature T is 80 ° C. or higher, and if T <80 ° C., step 9
Then, the heating control based on this step 9 is continued, and if T ≧ 80 ° C., the LEDs of the heat retention mode display section 26 and the hot mode display section 27 are turned on (step 11), and it is ready to eat. Is displayed and the process proceeds to step 12. In step 12, it is determined whether or not the sensed temperature T is 90 ° C. or higher. If T <90 ° C., the process proceeds to step 9, and the heating control based on this step 9 is continued, and T ≧
If it is 90 ° C, move to step 13 and cook rice heater 10
Power off, side heat retention heater 11 and lid heat retention heater
12 is cut off at T ≧ 90 ° C. and turned on at T <90 ° C. When 10 minutes have passed in step 14, heating by the heating control means 53 is stopped, and step 1
Then, the heat retention control means 52 performs heat retention again.
In step 8, when the hot switch 31 is pressed twice or more, the process proceeds to step 5, where the operation of the hot switch 31 is invalidated and the buzzer 49 notifies the heating control means 53. It prevents the deterioration of rice due to multiple operations.

As described above, according to the above embodiment, when the heating control means 53 controls the heating while the temperature is kept warm by the operation of the hot switch 31, or when the rice is cooked immediately after the rice cooking operation, the rice temperature is about to be eaten. When the temperature of 80 ° C or higher is reached, the LED of the hot-mode display unit 27 lights up to display the state, so that the user does not have to open the lid 7 and eat the rice directly as in the conventional example. You can see that the temperature is suitable for the taste.

Further, when the rice temperature is 80 ° C. or higher, heating by the heating control means 53 is unnecessary, but if the user mistakenly operates the hot switch 31, the buzzer is immediately activated.
Since the notification by 49 and the invalidation of the operation of the hot switch 31 are performed, the misuse can be prevented and the user can understand the misuse. Furthermore, the notification by the buzzer 49 and the disabling of the operation of the hot switch 31 also operate when the control by the heating control means 53 is performed again during the heat retention, so that the heating control means 53 is repeatedly used. By heating, it is possible to prevent yellowing of rice caused by so-called Maillard reaction, which occurs when the temperature of rice becomes high, and to prevent deterioration of fatty acid due to oxidation.

During the heating operation by the heating control means 53,
Since the inside of the container 6 is kept warm and there is almost no water 2 for transferring heat, the heat is hard to be transferred to the center of the container 6. That is, in order to heat the rice 1 in the container 6 without scorching, the side heat insulation heater 11 and the lid heat insulation heater 12 are used to indirectly heat the rice for about 30 to 60 minutes with a small heating amount. It is necessary to control the switching on and off while applying electricity, but this causes a problem that it takes too much heating time. Therefore, in this embodiment, first, the rice cooking heater 10 is turned on and off at intervals of 30 seconds to increase the amount of heat as the primary heating, and then the rice cooking heater is used as the secondary heating.
The amount of heat is reduced by repeating the pattern of 10 seconds of energization for 10 seconds and 60 seconds of power interruption to gradually heat from the bottom of the container 6, and the rice heating heater 10 switches the electricity on and off to burn the rice temperature. In addition to the indirect heating by the side warming heater 11 and the lid warming heater 12, the rice cooking heater 10 is energized up to the eating temperature of 90 ° C. The heating time can be significantly shortened by directly heating with a reduced rate so as not to cause charring.

The present invention is not limited to the above embodiment, and various modifications can be made. For example, the rice cooking heater may be one that heats the container by electromagnetic induction heating.

[0020]

According to the present invention, a container for containing cooked rice, a heating means for heating the container, a temperature detecting means for detecting the temperature of the container, and a rice cooking operation based on the temperature sensed by the temperature detecting means. Rice cook control means for controlling, heat retention control means for keeping the cooked food at about 67 ° C to 78 ° C after the cooking operation, and heating the cooked rice kept at this predetermined temperature to about 80 ° C to 95 ° C. It is provided with a heating control means and a display means for displaying the fact when the cooked food is 80 ° C. or higher after the rice cooking operation, and the rice temperature can be controlled without directly eating the rice in the container. It is possible to provide a rice cooker capable of knowing that the temperature is suitable for the taste.

[Brief description of drawings]

FIG. 1 is a block diagram showing a first embodiment of the present invention.

FIG. 2 is a sectional view of the same rice cooker.

FIG. 3 is a front view of the same display operation unit.

FIG. 4 is a circuit diagram of the same as above.

FIG. 5 is a graph showing changes in temperature with time and timing of heating.

FIG. 6 is a graph showing the display state and the timing of each control pattern after the above rice cooking operation.

FIG. 7 is a flowchart of the same heat retention operation.

[Explanation of symbols]

 1 rice (cooked food) 6 container 10 rice cooking heater (heating means) 11 side heat retention heater (heating means) 12 lid heat retention heater (heating means) 13 temperature sensor (temperature detection means) 27 hot mode display (display) Means) 51 Rice cooking control means 52 Heat retention control means 53 Heating control means

Claims (1)

[Claims] 1. A container for containing rice to be cooked, a heating means for heating the container, a temperature detecting means for detecting the temperature of the container, and a rice cooking operation for controlling the rice cooking operation based on the temperature sensed by the temperature detecting means. Control means, heat retention control means for keeping the cooked food at about 67 ° C. to 78 ° C. after the rice cooking operation, and the cooked food kept at this predetermined temperature is about 80 ° C.
A rice cooker comprising: heating control means for heating to 95 ° C. to 95 ° C .; and display means for displaying the fact when the cooked food is 80 ° C. or higher after the rice cooking operation.