JPH0813288B2 - Electric rice cooker - Google Patents

Description

TECHNICAL FIELD The present invention relates to an electric rice cooker having a heat retaining function.

2. Description of the Related Art Recent electric rice cookers having a heat-retaining function are naturally required to be cooked well, and as a result, there has been a demand for a more delicious heat-retaining function.

Figures 4 and 5 of a conventional electric rice cooker of this type
This will be described with reference to the drawings.

As shown in FIG. 4, a container 2 provided with a lid 1 on the top and containing rice and water, a bottom heater 3 for heating the bottom portion of the container 2, and a body heater 4 for heating the side portion of the container 2 And the thermistor 5 for detecting the temperature of the container 2 and a signal from the thermistor 5 are input, and immediately after the heat-insulating process is started from the rice cooking process, the temperature of the container 2 detected by the thermistor 5 is a prescribed heat-insulating property. The control circuit board 6 controls the bottom heater 3 and the body heater 4 so that each of the bottom heater 3 and the body heater 4 is energized or stopped at a constant energization rate so as to reach a temperature.

Next, the operation of this electric rice cooker will be described with reference to the flowchart of FIG.

In FIG. 5, in step 10, the rice cooking process is performed. In step 11, it is determined whether or not the rice cooking process is completed. If the rice cooking is not completed, the process returns to step 10 and steps 10 to 11 are repeated until the rice cooking is completed.

When the rice cooking is completed, the process proceeds to step 12 and the temperature of the container 2 is input by the thermistor 5. Next, in step 13, if the temperature does not reach the heat retention temperature (71.5 ° C),
At 14, the body heater 4 is energized at 15/16 and the bottom heater 3 is energized at a duty ratio of 1/16, and if the temperature exceeds the heat retention temperature, step 15
Then, the energization of the body heater 4 and the bottom heater 3 is stopped. After performing steps 14 and 15, return to step 12. Step 12
15 was repeated, and the temperature of the container 2 was controlled to be the heat retaining temperature, and the rice in the container 2 was kept warm.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention In such a conventional electric rice cooker, when the lid is opened and reclosed while the temperature is kept warm, the lid portion is cold. There was a problem that the rice that dropped on top and kept warm contained a lot of water and lost its shape or became white.

Means for Solving the Problems The present invention solves the above-mentioned problems, and prevents the dew from adhering to the inside of the lid by controlling the heating of the lid on the top of the container, and deteriorating the taste, shape, etc. of the rice due to the dew deposition. It is intended to keep warm without.

Means for Solving the Problems In order to achieve the above-mentioned object, the present invention has a container provided with a lid on the top for containing rice and water, a bottom heater for heating the bottom part of the container, and a side part for heating the container. A body heater, a lid heater for heating the inside of the lid of the container, a bottom temperature detecting means for detecting the temperature of the bottom portion of the container, and a lid temperature detecting means for detecting the temperature of the lid portion of the container, The bottom temperature detecting means and the control means for inputting the output signal of the lid temperature detecting means are provided, and the control means controls the temperature obtained by the output signal of the bottom temperature detecting means immediately after entering the heat retaining step from the rice cooking step. When the lid heater and the body heater are energized at a constant duty ratio until the temperature falls below the specified heat retention temperature, and the temperature obtained by the output signal of the bottom temperature detection means falls below the specified heat retention temperature It's temperature As described above, if the bottom heater and the body heater are controlled so as to energize or stop energizing at a constant energization rate, and if the temperature obtained by the output signal of the lid temperature detecting means exceeds a specified temperature. For example, the control for stopping the heating by the lid heater is a means for solving the problem.

Effect The present invention controls the energization to the lid heater and the body heater until the bottom temperature of the container becomes equal to or lower than the specified heat retention temperature after the rice cooking process to the heat retention process having the above-described configuration, and the lid heater is operated. It is possible to prevent dew from adhering to the inside of the lid above the container by heating and controlling the temperature inside the lid so as not to drop. Further, when the bottom temperature becomes lower than the heat retention temperature, the body heater and the bottom heater are controlled to keep the bottom temperature at a constant heat retention temperature, and the lid heater is not heated beyond the specified temperature by the lid temperature detection means. Can be controlled.

Example Hereinafter, an example of the present invention will be described with reference to FIGS. 1, 2, and 3.

As shown in the figure, the container 21 is provided with a lid 22 on the upper part and is filled with rice and water. The bottom portion of the container 21 is heated by the bottom heater 23, and the side portion is heated by the body heater 24. Lid heater 25
Heats the inside of the lid 22. The bottom temperature detecting means 26 detects the temperature of the bottom portion of the container 21. The lid temperature detecting means 27 detects the temperature of the lid 22. The control means 28 inputs the signals of the bottom temperature detecting means 26 and the lid temperature detecting means 27, and from the time immediately after entering the heat retaining step from the rice cooking process until the output of the bottom temperature detecting means 26 becomes equal to or lower than the specified heat retaining temperature. , The lid heater 25 and the body heater 24 are controlled at a constant duty ratio, and when the output of the bottom temperature detecting means 26 becomes equal to or lower than a specified heat retention temperature, the bottom heater 23 and the body heater 24 are controlled to reach the heat retention temperature. If the output of the lid temperature detecting means 27 is equal to or lower than a specified temperature, the lid heater 25 is energized and the specified temperature is exceeded. The lid heater 25 controls to stop heating.

Next, FIG. 2 is a specific circuit diagram. The start key 29 is for starting the rice cooking process, and the cancel key 30 is for canceling the rice cooking process and the heat retaining process. A bottom temperature detection means (hereinafter referred to as a first thermistor) 26 detects the bottom temperature of the container 21 and inputs it to the first A / D converter 31, and this first A / D converter
Reference numeral 31 A / D converts the signal from the first thermistor 26. The lid temperature detecting means (hereinafter referred to as the second thermistor) 27 is a container
The lid temperature of 21 is detected and input to the second A / D converter 32, and the second A / D converter 32 A / D converts the signal from the second thermistor 27. The relay 33 is for energizing the bottom heater 23 and has a relay coil 33a and a relay contact 33b. The relay drive unit 34 drives the relay 33. The relay 35 is for energizing the body heater 24,
It has a relay coil 35a and a relay contact 35b. The relay drive unit 36 drives the relay 35. The relay 37 is for energizing the lid heater 25.
It has a and a relay contact 37b. The relay drive unit 38 drives the relay 37. The input unit 39 inputs signals from the start key 29, the cancel key 30, the first A / D converter 31, and the second A / D converter 32. The output unit 40 is a relay drive unit 34, 36,
Outputs the relay open / close signal to each of 38. The control unit 41 controls the output unit 40 according to the signal input from the input unit 39. The microcomputer 42 has an input section 39 and an output section 4
0 and the control unit 41.

FIG. 3 is a flow chart showing the operation of the microcomputer 42. The operation will be described with reference to this flow chart.

In FIG. 3, the start key 29 is input in step 50, it is determined in step 51 whether the key pressed is start 29, and steps 50 to 51 are repeated until the start key 29 is pressed. If the start key 29 is pressed in step 51, the process proceeds to step 52 to execute the rice cooking process. In step 53, it is judged whether or not the rice cooking process is completed. If the rice cooking is not completed, the process returns to step 52 and the steps are continued until the rice cooking is completed.
Repeat 52 to 53. If cooking is over, step 54
Then, the body heater 24 is energized at a rate of 3/16 and the lid heater 25 is energized at a rate of 3/16. In step 55, the container is detected by the bottom temperature detecting means 26.
The bottom temperature of 21 is detected, and it is determined whether or not the bottom temperature detected in step 56 is lower than the heat retention temperature (71.5 ° C.). If it is not lower than the heat retention temperature, the process proceeds to step 57. The cancel key 30 is entered in step 57, and the cancel key 30 is entered in step 58.
If it is not determined that is pressed, the process returns to step 54.

Steps 54 to 58 are repeated until it is determined in step 56 that the bottom temperature is lower than or equal to the heat retention temperature or in step 58 that the cancel key 30 is pressed.

If the bottom temperature detected by the bottom temperature detection means 26 is lower than the heat retention temperature in step 56, the process proceeds to step 59, and the bottom temperature detection means 26 detects the bottom temperature of the container 21 again. If the bottom temperature does not reach the heat retention temperature (71.5 ° C) in step 60, the body heater 24 is set to 15/16 and the bottom heater 23 is set to 1/16 in step 61.
When the bottom temperature exceeds the heat retention temperature, the energization of the body heater 24 and the bottom heater 23 is stopped in step 62. After executing steps 61 and 62, the process proceeds to step 63, and the lid temperature of the container 21 is detected by the lid temperature detecting means 27. If the lid temperature has not reached the set temperature (112 ° C.) in step 64, the lid heater 25 is energized in step 65, and if the lid temperature exceeds the set temperature, the lid heater 25 is de-energized in step 66. . After executing step 65 and step 66, the process proceeds to step 67 and the cancel key 30 is input. Step 78
If it is not determined that the cancel key 30 has been pressed in step 1, the process returns to step 59. Steps 59 to 68 are repeated until it is determined in step 68 that the cancel key 30 has been pressed.

When the cancel key 30 is pressed in step 58 and step 68, the process proceeds to step 69, the energization of all heaters is stopped, and the process returns to step 50.

Thus, according to the electric rice cooker of the embodiment of the present invention, after shifting from the rice cooking process to the heat retaining process, the body heater 24 and the lid heater 25 are heated until the temperature falls below the heat retaining temperature, and the dew forms on the lid 22. It does not occur, does not drop on the rice and deteriorates the taste, shape, etc. of the rice, and after the temperature falls below the heat retention temperature, heating control is performed by the bottom temperature and the lid temperature, and the bottom of the container 21 is controlled. The temperature is adjusted to the heat retention temperature. At this time, the bottom temperature detecting means 26 controls the heating of the bottom heater 23 and the body heater 24, and the lid temperature detecting means 27 controls the heating of the lid heater 25. The heating control of the heater 25 is controlled independently of the bottom temperature, and it is possible to always prevent the generation of dew in the container. further,
When the temperature of the lid 22 rises abnormally, the heating of the lid heater 25 is stopped, so that it is possible to prevent the user from being burned and the device from being damaged.

EFFECTS OF THE INVENTION As is clear from the above examples, according to the present invention, when the temperature of the container immediately after the heat retention step is high and a large amount of water vapor is generated, the body heater and the lid heater are heated to cause dew on the lid. Since it is controlled so that it does not occur, it is possible to prevent dew falling on rice and deteriorating the taste and shape of the rice. Even if the bottom temperature of the container falls below the heat retention temperature after entering the heat retention step, the lid heater heating control is independent of the bottom temperature, so that the dew inside the container is always prevented. be able to. Furthermore, if the temperature of the bottom of the container drops below the heat retention temperature after entering the heat retention process, even if the lid temperature rises abnormally due to the heating of the lid heater, the heating of the lid heater is stopped if it reaches the specified temperature. Therefore, it is possible to prevent the user from being burned and the device from being damaged.

[Brief description of drawings]

FIG. 1 is a block diagram of an electric rice cooker according to an embodiment of the present invention,
FIG. 2 is a specific circuit diagram of the electric rice cooker, FIG. 3 is an operation flowchart of a microcomputer in the electric rice cooker, FIG. 4 is a vertical sectional view of a conventional electric rice cooker, and FIG. It is an operation | movement flowchart of an electric rice cooker. 21 ... Container, 22 ... Lid, 23 ... Bottom heater, 24 ... Body heater, 25 ... Lid heater, 26 ... Bottom temperature detecting means, 27 ... Lid temperature detecting means, 28 ... Control means.

Claims (1)

[Claims] 1. A container provided with a lid on the top for containing rice and water, a bottom heater for heating a bottom portion of the container, a body heater for heating a side portion of the container, and an inside of the lid of the container. Lid heater, bottom temperature detection means for detecting the temperature of the bottom portion of the container, lid temperature detection means for detecting the temperature of the lid portion of the container, output of the bottom temperature detection means and the lid temperature detection means A control means for inputting a signal is provided, and the control means energizes the lid heater and the body heater at a constant energization rate immediately after shifting from the rice cooking step to the heat retention step, and then once the bottom temperature detection means After the temperature obtained by the output signal becomes equal to or lower than the specified heat retention temperature, the bottom heater and the body heater are each energized at a constant energization rate or controlled so that the energization is stopped. And the above Electric rice cooker temperature obtained by the output signal of the temperature detecting means becomes controlled to stop heating by the lid heater if exceeds a predetermined temperature.