JPH0515433A - Thermos type rice cocker - Google Patents

Abstract

PURPOSE:To provide a thermos type rice cooker which can reduce affection variations in the room temperature give to a temperature detecting means during a temperature holding mode, and which can maintain the temperature of the inside of a pot constant. CONSTITUTION:A control means 7 controls a heater 12 so as to set the temperature of a pot 11 at a temperature holding and controlling value, and a first timer means 15 measures the passage of time by 30min while a second timer means 16 counts a heating time for the heater 12. Temperature holding and controlling data stored in a memory means is changed in accordance with a percentage of the energization time for the heater 12 within 30min, thereby it is possible to allow the temperature of boiled rice to approach the temperature holding and controlling value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a jar rice cooker mainly used at home and having a heat retaining function.

[0002]

2. Description of the Related Art In recent years, various efforts have been made to improve the rice cooking performance of jar rice cookers. But,
The heat-retaining performance of the jar function has not been studied so much, but with the growing need for heat-retaining for a long time, measures such as odor during heat-retention and yellowing of rice have become necessary.

The heat retaining process of the conventional jar rice cooker will be described below. FIG. 6 shows the configuration of a conventional jar rice cooker. In FIG. 6, 1 is a pot for putting rice and water, 2
Is a heater for heating the pot 1, 3 is temperature detecting means for detecting the temperature in the pot 1, 4 is a storage means, and the heater 2 is
Control temperature data including heat retention control temperature data for controlling the temperature is stored. Reference numeral 5 is a control means for controlling the heater 2 so that the temperature in the pan 1 reaches a heat retention control temperature preset in the storage means 4 during heat retention.

The operation of the heat retaining process of the conventional jar rice cooker configured as described above will be described below. When entering the heat retention step, the temperature inside the pan detected by the temperature detection means is controlled by the heat retention control temperature (about 7
If the temperature is below 1.5 ℃, heat the pot 1 with the heater 2
When the temperature exceeds the heat retention temperature, the power supply to the heater 2 is stopped and the pot 1 is not heated. By continuing this control operation, the temperature inside the pan 1 is attempted to be maintained at a constant heat retention control temperature. FIG. 7 shows the above operation, in which the vertical axis indicates the amount of heating by the heater and the temperature inside the pan, and the horizontal axis indicates time.
From this FIG. 7, it can be seen that there is a difference in the temperature that is actually controlled with respect to the heat retention control temperature point. FIG. 8 shows the correlation between the heat retention control temperature of a conventional jar rice cooker and room temperature. FIG. 8 shows the dependence of the rice temperature on the room temperature when the temperature is controlled at the heat retention control temperature point. FIG. 9 shows the correlation between the heating time per 30 minutes of the heater and the room temperature.

[0005] Next, the rice that is kept warm will be described. The yellowing of the color of the rice means that the rice temperature is the heat retention control temperature (around 70 ° C).
If you go over, it will proceed rapidly. The odor of rice becomes stronger when the temperature of the rice exceeds the heat retention control temperature (around 70 ° C) because the fatty acids contained in the rice are decomposed by the oxidation action.
It is known that when the temperature is lower than the heat retention control temperature, the odor becomes strong due to the propagation of various bacteria.

[0006]

However, in the above-mentioned conventional structure, as is apparent from FIG. 7, the temperature change due to room temperature affects the temperature detecting means, so that the temperature between the heat retention control temperature and the actual rice temperature is increased. There was a problem that the deviation occurred.

The present invention solves the above-mentioned conventional problems by reducing the effect of room temperature changes on the temperature detecting means,
It is an object to provide a jar rice cooker that keeps the temperature of rice in a pan constant.

[0008]

In order to achieve this object, the jar rice cooker of the present invention detects the temperature inside the pan, the pan for putting rice and water, the heating means for heating the pan. A temperature detecting means, a storage means for storing control temperature data including a plurality of heat retention control temperature data for controlling the heating means, and a time measurement start after the heat retention step and output at a predetermined time. A first timer means, a second timer means for measuring and outputting a heating time of the heating means until the output of the first timer means is received after shifting to the heat retaining step, and the first timer means for shifting to the heat retaining step. The timer means is started to control the heating means so that the temperature in the pan reaches the heat retention control temperature preset in the storage means during heat retention, and the storage is performed by the output of the second timer means. Remembered by means It has a configuration of a control means for changing the heat keeping control temperature data.

Further, the control means starts the clocking of the first timer means at the time of transition to the heat retention step, and the heating is performed so that the temperature in the pan reaches the heat retention control temperature preset in the storage means at the time of heat retention. The temperature control data stored in the storage means is changed by the output of the second timer means, and at the same time the contents of the time counts of the first timer means and the second timer means are initialized. It is configured to change.

[0010]

With this construction, the heating means is controlled by the control means so as to reach a predetermined heat retention control temperature after the heat retention step is started, and the second timer means is operated when the predetermined time has elapsed by the first timer means. If the timed heating time of the heating means is more than a predetermined time, the temperature of the heat retention control stored in the storage means can be changed to bring the temperature of the rice close to the temperature of the heat retention control.

Further, after the heat retention step is started, the control means controls the heating means so that the temperature becomes a predetermined heat retention control temperature.
If the heating time of the heating means measured by the second timer means is equal to or longer than the predetermined time when the predetermined time has elapsed by the second timer means, the heat retention control temperature stored in the storage means is changed at the same time as the first time. It is possible to initialize the timekeeping contents of the timer means and the second timer means to bring the temperature of the rice close to the heat retention control temperature while correcting the temperature of the rice at a constant cycle.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, 11 is a pot for putting rice and water, 12 is a heater for heating the pot 11, 13 is a temperature detecting means for detecting the temperature in the pot 11, and 14 is for controlling the heater 12. Storage means for storing control temperature data including a plurality of heat retention control temperature data for measuring the heating time of the heater 12 until the output of the first timer means 15 is received after shifting to the heat retention step. The second timer means 17 for outputting the output is a control means for starting the time measurement of the first timer means 15 at the time of transition to the heat retention step.
The heater 12 is controlled so that the temperature in 1 becomes the heat retention control temperature preset in the storage means 14 during heat retention, and is stored in the storage means 14 by the output of the second timer means 16. Change the heat retention control temperature data.

FIG. 2 shows a concrete circuit diagram of the jar rice cooker according to the first and second embodiments of the present invention.
In FIG. 2, reference numeral 20 denotes an AC power supply, and this AC power supply 2
A series circuit of a heater 21 for heating the pan 11 and a relay contact 22 is connected to 0, and a signal from an output port of a microcomputer 29 causes a current to flow through a relay coil 23 via a transistor 24 to open / close the relay contact 22. Is configured as follows. 25 is a power supply for the microcomputer 29. Reference numeral 26 is a thermistor for detecting the temperature in the pot 11, which is connected to the A / D converter 27 and inputs data to the microcomputer 29. Reference numeral 28 is a switch for starting rice cooking and ending heat retention. A microcomputer 29 controls rice cooking and heat retention.

The operation of the jar rice cooker configured as described above will be described with reference to the flowchart of FIG. Wait until the switch 28 is pressed in step 31.
If the switch 28 is pressed, the process proceeds to step 32 to cook rice. In step 33, the temperature of the pan 11 is input from the thermistor 26 and it is determined whether or not the temperature reaches the rice cooking end temperature. Steps 32 and 33 are repeated until the rice cooking end temperature is reached. When the temperature reaches the rice cooking end temperature, 72 ° C. is set as the heat retention control temperature in step 34. In step 35, the time after the heat retention is started is measured. In step 36, the temperature inside the pan 11 is input from the thermistor 26. Step 37
In step 38, it is determined whether or not the temperature exceeds 72 ° C., and if it does not exceed 72 ° C., the heater 21 is controlled to be energized in step 38, the energization time of the heater 21 is measured in step 39, and the process proceeds to step 41. If the temperature exceeds 72 ° C. in step 37, the heater 21 is controlled to be de-energized in step 40 and the process proceeds to step 41. In step 41, it is determined whether the heat retention time has exceeded 30 minutes, and if not, the flow proceeds to step 42. In step 42, it is determined whether the switch 28 has been pressed, and if it has been pressed, step 31
Return to step 35, and if not pressed, return to step 35. Steps 35 to 42 are repeated if the switch 28 is not pressed within 30 minutes from the start of heat retention. If the heat retention time exceeds 30 minutes in step 41, step 4
If the energization time of the heater 21 measured in step 39 is 10 minutes or more in step 39, the heat retention control temperature is reset to 70 ° C. in step 44 and the process proceeds to step 45. Step 43
If the energization time of the heater 21 is less than 10 minutes, the process proceeds to step 45 and the temperature of the pan 11 is input from the thermistor 26. In step 46, it is judged whether or not the temperature has exceeded the heat retention control temperature (here, 70 or 72 ° C.), and if not, the heater 21 is controlled to be energized in step 47. If the temperature has exceeded the heat retention control temperature in step 46, the power supply to the heater 21 is controlled to be cut off in step 48, and the process proceeds to step 49. Switch 2 in step 49
It is determined whether or not 8 is pressed. If it is pressed, the process returns to step 31, and if it is not pressed, the process returns to step 45. Step 4
If switch 28 is not pressed in step 9, step 4
Repeat 5 to 49.

As described above, according to the jar rice cooker of the embodiment of the present invention, energization is controlled so as to reach the heat retention control temperature (72 ° C.) in the heat retention step, and the energization time of the heater is extended when the room temperature is low. , This energizing time is 1 every 30 minutes
If it is 0 minutes or more, it is detected that the room temperature is low. If the room temperature is low, the temperature of the rice will be higher than the temperature control temperature (Fig. 8).
(See), so lower the temperature control setting (72 ℃
Changed to 70 ° C). From the above operation, the actual temperature of the rice is kept around 72 ° C even when the room temperature is low.

A second embodiment of the present invention will be described below with reference to the drawings. In FIG. 4, 11 is a pot for putting rice and water, 12 is a heater for heating the pot 11, 13
Is a temperature detecting means for detecting the temperature in the pot 11, 14 is a storage means for storing control temperature data including a plurality of heat retention control temperature data for controlling the heater 12.
Reference numeral 5 is a first timer means for starting time measurement after shifting to the heat retention step and outputting at a predetermined time, and 16 is the heater 12 of the heater 12 from the transition to the heat retention step until receiving the output of the first timer means 15. Second timer means for measuring and outputting the heating time. The above is the same as in FIG. The difference from the configuration of FIG. 1 is that the control means 18 starts the timekeeping of the first timer means 15 at the time of transition to the heat retention process, and the temperature inside the pan 11 is preset in the storage means 14 at the time of heat retention. The heater 12 is controlled so as to reach the temperature, and the second
The temperature control data stored in the storage means 14 is changed by the output of the timer means 16 and the timing contents of the first timer means 15 and the second timer means 16 are initialized at the same time. Is.

The operation of the jar rice cooker configured as described above will be described with reference to the flowchart of FIG. In step 61, the process waits until the switch 28 is pressed.
If the switch 28 is pressed, the process proceeds to step 62 to cook rice. In step 63, the temperature of the pot 11 is input from the thermistor 26 and it is determined whether or not the temperature reaches the rice cooking end temperature. Steps 62 and 63 are repeated until the rice cooking end temperature is reached. When the rice cooking end temperature is reached, in step 64, the heat retention control temperature is set to 72 ° C. First in step 65
The contents of the timer means 15 are initialized, and the contents of the second timer means 16 are initialized in step 66. Step 67
Measure the time since you started to keep warm. In step 68, the temperature inside the pan 11 is input from the thermistor 26. In step 69, it is determined whether or not the temperature exceeds the heat retention control temperature (here, 70 or 72 ° C.), and if not, the heater 21 is controlled to be energized in step 70, and the energization time of the heater 21 is measured in step 71. Do step 73
Go to. If the temperature has exceeded the heat retention control temperature in step 69, control is performed in step 72 so that the heater 21 is de-energized, and the process proceeds to step 73. In step 73, it is determined whether the heat retention time has exceeded 30 minutes, and if not, the flow proceeds to step 74. In step 74, it is determined whether or not the switch 28 is pressed. If the switch 28 is pressed, the process returns to step 61, and if not, the process returns to step 67. If the switch 28 is not pressed within 30 minutes after the warming is started, steps 67 to 74 are repeated. Step 7
If the heat retention time exceeds 30 minutes in step 3, the process proceeds to step 75 and the energization time of the heater 21 measured in step 71 is set to 1
If it is 0 minutes or more, in step 76, the heat retention control temperature is set to 7
Reset 0 ° C. and proceed to step 78. If the energization time of the heater 21 is less than 10 minutes in step 75, the heat retention control temperature is set to 72 ° C. in step 77. Next, at step 78, it is determined whether the switch 28 has been pressed. If it has been pressed, the procedure returns to step 61, and if not, step 65
Return to.

As described above, according to the jar rice cooker of the second embodiment of the present invention, the heat retention step is started and the heat retention control temperature (72
The energization is controlled so that the temperature becomes room temperature), and the energization time of the heater is extended when the room temperature is low. Therefore, if the length of the energization time is 10 minutes or more per 30 minutes, the room temperature is detected to be low.
If the room temperature is low, the temperature of the rice is higher than the temperature control temperature (see FIG. 8), so the temperature control temperature is lowered (change from 72 ° C. to 70 ° C.). Further, when the heat retention control temperature is reset, the first timer means and the second timer means are initialized, so that the heat retention control temperature is reset at any time in a 30-minute cycle. From the above operation, the effect of room temperature on the thermistor can be reduced and the actual temperature of the rice can be maintained at around 72 ° C. while the temperature is kept warm.

Although a heater is used as the heating means in this embodiment, an induction heating coil, a gas combustor, or a heating means combining a heater and an induction heating coil may be used.
In short, any heating means for keeping the temperature may be used.

[0021]

As is apparent from the above embodiments, according to the present invention, it is possible to reduce the influence of changes in room temperature on the temperature detecting means, and bring the temperature of the rice in the pan close to a predetermined temperature control temperature. , It is possible to reduce the odor and yellowing of rice during heat retention.

Further, according to the present invention, since the temperature of the rice is controlled so as to approach the predetermined temperature control temperature at regular intervals, it is possible to reduce the odor and yellowing of the rice when it is kept warm for a long time.

[Brief description of drawings]

FIG. 1 is a block diagram of a jar rice cooker according to a first embodiment of the present invention.

FIG. 2 is a specific circuit diagram of the jar rice cooker according to the first and second embodiments of the present invention.

FIG. 3 is a flowchart showing the operation of the microcomputer of the jar rice cooker according to the first embodiment of the present invention.

FIG. 4 is a block diagram of a jar rice cooker according to a second embodiment of the present invention.

FIG. 5 is a flowchart showing the operation of the microcomputer of the jar rice cooker according to the second embodiment of the present invention.

FIG. 6 is a block diagram of a conventional jar rice cooker.

FIG. 7 is a diagram showing a heat retaining operation of a conventional jar rice cooker.

FIG. 8 is a diagram showing a correlation between rice temperature and room temperature during the heat retention process of the conventional jar rice cooker.

FIG. 9 is a diagram showing the correlation between the heating time of the pan by the heater and the room temperature during the heat retention process of the conventional jar rice cooker.

[Explanation of symbols]

11 pots 12 heater 13 Temperature detection means 14 storage means 15 First timer means 16 Second timer means 17 Control means 18 Control means 29 Microcomputer

Claims (2)

[Claims] 1. A pot for containing rice and water, a heating means for heating the pot, a temperature detecting means for detecting the temperature in the pot, and a plurality of heat retention control temperature data for controlling the heating means. Storage means for storing control temperature data including, a first timer means for starting time measurement after shifting to the heat retention step and outputting at a predetermined time, and a first timer after shifting to the heat retention step Second timer means for measuring and outputting the heating time of the heating means before receiving the output of the means, and for starting the time counting of the first timer means at the time of transition to the heat retention step, the temperature in the pan is stored when the temperature is kept warm. The heating means is controlled so as to reach the heat retention control temperature preset in the means, and the heat retention control temperature data stored in the storage means is changed by the output of the second timer means. Jar rice cooker. 2. The control means controls the heating means so that the temperature of the first timer means is started at the time of transition to the heat retention process and the temperature in the pan reaches the heat retention control temperature preset in the storage means at the time of heat retention. Then, the heat retention control temperature data stored in the storage means is changed by the output of the second timer means, and at the same time, the clocked contents of the first timer means and the second timer means are initialized. Jar rice cooker.