JPH09248245A - Rice cooker with automatic controller of warming condition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rice cooker with automatic controller of warning condition capable of keeping cooked rice not excessively dried in warming even in the case where the amount of cooked rice in the cooker is little. SOLUTION: This rice cooker 1 is equipped with a cooking pan 3 and heaters 7 and 3 to heat the cooking pan 3. Further, a means (micro switch 25) to detect he weight of the cooking pan 3 and a warming heater control means (controller) to automatically control the amount of neat of the warming heaters 7 and 13 corresponding the weight of the cooling pan 3 are also equipped. Excessive drying of cooled rice is prevented when the amount of rice is little since the heat (temperature) for warming is lowered to prevent unnecessary evaporation of water from cooked rice.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a rice cooker having a heat retaining function for a rice cooker. In particular, the present invention relates to a heat retention automatic adjustment type rice cooker capable of automatically adjusting the heat quantity during heat retention according to the amount of rice in the rice cooker.

[0002]

2. Description of the Related Art A conventional technique will be described by taking a gas rice cooker as an example. FIG. 5 is a system diagram showing a schematic configuration of a heating / heat-retaining system of a conventional general gas rice cooker. Rice cooker 1 in Figure 5
Is equipped with a rice cooker (inner pot) 3. In the rice cooker 3,
Contains rice 11. The rice cooker 3 is covered with a lid 5. A bottom thermistor (temperature sensor) 15 is in contact with the bottom 12 of the rice cooker 3. The bottom thermistor 15 detects the temperature of the bottom of the pot to detect whether the rice is cooked or cooked empty. When the rice cooking is started, the temperature of the water in the pot 3 rises, and when the water is boiling, the bottom thermistor detection temperature is maintained at about 110 ° C. However, when the water in the kettle 3 evaporates and disappears, the temperature of the kettle bottom 12 rises again. When the temperature of the kettle bottom 12 reaches 145 ° C., for example, it is determined that rice has been cooked, and the gas (main) burner 17 is automatically stopped.

The main burner 17 is provided below the bottom 12 of the rice cooking pot 3 and heats the pot bottom 12. A pilot burner 19 is provided beside the main burner 17. The pilot burner 19 is for igniting the main burner 17. The thermocouple 23 provided beside the pilot burner 19 detects the temperature of the flame of the pilot burner 19 and detects its extinction. That is, when the main burner 17 and the pilot burner 19 are extinguished due to spilling or the like after the start of rice cooking, the electromotive force of the thermocouple 23 disappears, and the signals cause the safety valves (solenoid valves) 37 and 39 to close. Igniter 21
Is a device that ignites the pilot burner 19 with sparks. The two solenoid valves, the original solenoid valve 39 and the main solenoid valve 37, are provided in series in order to improve the reliability of gas shutoff. The control solenoid valve 35 on the downstream side of the main solenoid valve 37 is a valve for opening and closing the main burner row pipe 31 and is turned on and off at the start and end of rice cooking. The gas pipe 33 of the 19th row of the pilot burner is branched from the upstream side of the control solenoid valve 35.

Next, the heat retaining mechanism will be described. Bottom 1 of rice cooker 3
A ring-shaped heater 13 (heating wire) is arranged below the unit 2. The bottom heater 13 heats and keeps the rice cooker 3 warm from below. A ring-shaped heater 7 (heating wire) is also arranged on the lid 5. The lid heater 7 heats and keeps the rice cooker 3 warm from above. The temperature during this heat retention is 67 to 68 ° C. as the temperature detected by the bottom thermistor, and about 73 ° C. in rice. The heater is on at 67 ° C, 68
Turns off at ℃. The main board 27 controls each device based on a sensor signal from each sensor and an operation signal from the operation board 29.

[0005]

In the conventional rice cooker, the strength (heat amount) of the heat retaining heater is constant regardless of the amount of rice contained in the pot. Therefore, when the amount of cooked rice is small, the water may evaporate during the warming and the cooked rice may become sticky. It is an object of the present invention to provide a heat-retaining automatic-adjustment rice cooker that does not dry the heat-insulating rice even when the amount of rice in the rice cooker is small.

[0006]

In order to solve the above problems, an automatic heat-retention type rice cooker of the present invention is a rice cooker with a heat-retaining function, which includes a rice cooker and a heater for keeping the rice cooker warm. Yes; a means to detect the weight of the rice cooker,
A warming heater control means for automatically adjusting the heat quantity of the warming heater from small to large according to whether the weight of the rice cooker is light or heavy. When the amount of rice is small,
Since the amount of heat (temperature) for heat retention is lowered, unnecessary evaporation of water from the rice is eliminated, and the rice can be prevented from becoming dry.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described more specifically. FIG. 1 is a system diagram showing an outline of a heating / heat-retaining system of a heat-retention automatically adjusting rice cooker according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view showing details around the bottom thermistor and the micro switch of the heat retention automatic adjustment type rice cooker of FIG. 1. A feature of the rice cooker of FIG. 1 which is controlled automatically by heat retention is compared with the conventional rice cooker with heat retention function of FIG. 5 is that a micro switch 25 for detecting the position of the bottom thermistor 15 is provided.

The structure around the bottom thermistor 15 will be described with reference to FIG. The bottom thermistor 15 is biased upward by a coil spring 51 provided below it. The coil spring 51 is placed in a recess on the upper surface of the thermistor case guide 53. Case guide 5
3 is fixed to the main body (not shown) of the rice cooker.
The weight of the rice cooker (inner pot) 3 and its contents (about 3 kg) is
It is supported by the coil spring 51 via the bottom thermistor 15. Therefore, the amount of expansion and contraction of the coil spring 51 changes depending on the weight of the rice cooker 3, and the vertical position of the bottom thermistor 15 also changes.

A thermistor spindle 55 extending downward is connected to the lower surface of the bottom thermistor 15. A micro switch guide 59 is attached at a position where the thermistor spindle 55 is pulled out below the case guide 53. The micro switch guide 59 extends outward from the axis of the thermistor spindle 57, and the probe 2 of the micro switch 25 installed below the outer side thereof.
Facing 6 When the weight applied to the bottom thermistor 15 becomes heavy to some extent, the coil spring 5
As 1 and 56 contract, the bottom thermistor 15, thermistor spindle 57 and micro switch guide 59 slide down in the case guide 53. Then, when the micro switch guide 59 pushes the probe 26 of the micro switch 25, the micro switch is turned on. by this,
Detects a large amount of rice in the rice cooker.

Next, the structure and operation of the control device for the automatic heat retention type rice cooker of this embodiment will be described. FIG. 3 is a block diagram showing a configuration of a control device of the heat retention automatic adjustment type rice cooker of FIG. 1. FIG. 4 is a flowchart showing the operation of the control device of the heat retention automatic adjustment type rice cooker of FIG. 1. The temperature signals detected by the lid thermistor 9 and the bottom thermistor 15 are sent to the controller 71 (stored in the main board) and processed. The signal of the micro switch 25 is also sent to the controller 71. The controller 71 controls the lid heater 7 and the bottom heater 13 based on the information from the thermistors 9 and 15 and the microswitch 25.

Regarding the control operation of the controller 71, FIG.
This will be described with reference to FIG. After the start (101), it is first determined whether or not the heat is being maintained (102). If NO, the process returns to the start, and if YES, the process proceeds to the next step 103. Next, it is determined whether or not the micro switch is ON, that is, whether or not the amount of rice in the rice cooker is a predetermined amount or more. If NO (small amount of rice), go to step 104, and if YES (small amount of rice), go to step 105.

In step 104, the current temperature T and the low temperature keeping temperature T _L are compared. Here, the low-temperature heat retention temperature is a heat retention temperature set to a low level so that the rice does not crack when the amount of rice in the rice cooker is small. The value is 65 ° C. as an example. When the current temperature T is lower than the low temperature keeping temperature T _L (YES), the process proceeds to step 107 to turn on the heater. If not (NO)
Goes to step 106 to turn off the heater.

In step 105, the current temperature T and the high temperature keeping temperature T _H are compared. The high temperature retained temperature T _H, a reference made temperature incubation time is large amount of rice in rice in the pot. The value is 68 ° C. (as before) as an example. When the current temperature T is lower than the high temperature retained temperature T _H (YES)
Goes to step 107 to turn on the heater. If not (NO), proceed to step 106 to turn off the heater.

In the judgment in steps 104 and 105, a proper hysteresis is usually provided to prevent control hunting. In addition, the heating temperature is controlled by the pot bottom thermistor when the heater is strong or weak.

[0015]

As is clear from the above description, when the automatic heat-retaining type rice cooker of the present invention is used, when the amount of rice in the rice cooker is small, the heat-retaining heat amount and temperature are automatically lowered. The amount of water that evaporates from rice during heat retention is reduced, and the rice can be prevented from becoming dry.

[Brief description of drawings]

FIG. 1 is a system diagram showing an outline of a heating / heat-retaining system of a heat-retention automatically adjusting rice cooker according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing details of a bottom thermistor and a micro switch of the heat retention automatic adjustment type rice cooker of FIG.

FIG. 3 is a block diagram showing a configuration of a control device of the heat retention automatic adjustment type rice cooker of FIG. 1.

FIG. 4 is a flowchart showing the operation of the control device of the heat retention automatic adjustment type rice cooker of FIG. 1.

FIG. 5 is a system diagram showing an outline of the configuration of a heating / heat-retaining system of a conventional general gas rice cooker.

[Explanation of symbols]

1 Gas Rice Cooker 3 Rice Cooker 5 Lid 7 Lid Heater 9 Lid Thermistor 11 Rice 12 Bottom 13 Bottom Heater 15 Bottom Thermistor 17 Main Burner 19 Pilot Burner 21 Igniter 23 Thermocouple 25 Micro Switch 27 Main Board 29 Operation Board 31 Main Burner Row Gas Piping 33 Pilot burner row Gas piping 35 Control solenoid valve 37 Main solenoid valve 39 Main solenoid valve 41 Gas piping 51 Coil spring 53 Case guide 55 Thermistor spindle 56 Coil spring 59 Micro switch guide

Claims (3)

[Claims] 1. A rice cooker having a heat retaining function, comprising: a rice cooker; and a heater for keeping the rice cooker warm; the means for detecting the weight of the rice cooker and the weight of the rice cooker A heat retention automatic control rice cooker comprising: a heat retention heater control means that automatically adjusts the amount of heat of the heat retention heater. 2. The means for detecting the weight of the rice cooker comprises means for elastically holding the rice cooker (cook holding means) and means for detecting the position of the rice cooker on the cooker holding means (cook position detecting means). ), And the rice cooker according to claim 1, further comprising: 3. The hook holding means is a spring, and the hook position detecting means includes a temperature sensor attached to the tip of the spring and pressed against the bottom of the hook, and a micro switch for detecting the position of the temperature sensor. The rice cooker according to claim 2, which is automatically controlled.