JP7298878B2 - gas cooker - Google Patents

Description

TECHNICAL FIELD The present invention relates to a gas rice cooker capable of cooking rice by using a burner as a heat source.

A gas rice cooker is equipped with a clock function that counts the number of oscillation clocks of a crystal oscillator and measures the current time based on the integrated value so that timer rice cooking can be performed by setting the completion time of rice cooking.
The number of oscillation clocks of this crystal oscillator is easily affected by the ambient temperature. Therefore, in Patent Document 1, the temperature characteristics of a crystal oscillator are measured in advance, the values of the deviation of the oscillation frequency from the standard value in each temperature range are stored as a frequency fluctuation table, and the temperature measured by the temperature sensor is stored. An invention of a clock program is disclosed that calculates an error from data with reference to a frequency fluctuation table and corrects the time.

JP 2007-78405 A

However, if this timing program is applied to a gas rice cooker with a burner, the heat from the burner may cause a large error, and if timer cooking is used, the time when the rice is finished cooking may deviate greatly from the actual time.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a gas rice cooker having a highly reliable timekeeping function by reducing time lag.

In order to achieve the above object, the invention according to claim 1 provides a rice cooker with an open top, a lid closing the opening of the rice cooker, a burner for heating the rice cooker from below, and a bottom surface of the rice cooker. Equipped with a bottom temperature sensor that detects the temperature, an internal temperature sensor that is provided on the lid to detect the internal temperature of the rice cooker, and a clock function that measures the current time based on the clock count from the crystal oscillator. A gas rice cooker comprising control means for controlling combustion of a burner based on temperatures detected by a sensor and an internal temperature sensor , and a power cord having a power plug ,
The control means is provided below the rice cooker and the burner,
The control means controls when the temperature difference between the bottom surface temperature sensor and the internal temperature sensor is within a predetermined temperature while power is being supplied from the power plug , and the detected temperature of the bottom surface temperature sensor is a second predetermined temperature or less. Only in this case, the current time is corrected by correcting the clock count from the crystal oscillator using the temperature detected by the bottom temperature sensor and a frequency fluctuation table that presets the correction time for the clock count corresponding to the detected temperature. characterized by

According to the first aspect of the invention , it is possible to avoid correction when the difference between the temperatures detected by the bottom surface temperature sensor and the internal temperature sensor is large. Therefore, it is possible to provide a highly reliable timekeeping function by reducing time lag.
In particular , the control means is provided below the rice cooker and the burner , and the control means uses the temperature detected by the bottom temperature sensor and the frequency fluctuation table, so that the temperature detected by the bottom temperature sensor in the same temperature environment as the crystal oscillator. Based on this, the clock count number can be corrected more accurately.
Further, it is possible to avoid correction in a state where the temperature of the crystal oscillator, which is in the same temperature environment as the bottom surface temperature sensor, is high.

It is a perspective view of a gas rice cooker. 1 is a schematic diagram of the configuration of a gas rice cooker; FIG. FIG. 10 is a diagram showing correction characteristics of the number of clock counts;

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings.
FIG. 1 is a perspective view showing an example of a gas rice cooker, and FIG. 2 is a schematic view.
The gas rice cooker 1 includes a main body 2 with an upper opening and a lid 3 for opening and closing the upper opening of the main body 2. At the front lower part of the main body 2, there are operations for selecting a cooking menu, timer-cooking rice, and the like. A panel 4 is provided. The main body 2 is provided with a gas pipe 5 to which an external hose is connected, and a power cord (not shown).
A rice cooking pot 6 having an upper opening is detachably accommodated in the main body 2, and the lid body 3 is provided with an inner lid 7 for opening and closing the upper opening of the rice cooking pot 6 when the main body 2 is closed.
A burner 8 for heating the rice cooking pot 6 from below and a pot heater 9 for heating the lower region of the rice cooking pot 6 are provided in the main body 2 . A contacting lid heater 10 is provided.

On the other hand, the gas pipe 5 is provided with a main solenoid valve 11 for opening and closing the gas pipe 5, and a branch passage branched downstream of the main solenoid valve 11 is provided with a first solenoid valve 12 for opening and closing each branch passage. A second electromagnetic valve 13 is provided, respectively.
Further, inside the main body 2, there is provided a pot thermistor 14 that contacts the center of the bottom surface of the rice cooking pot 6 and detects the temperature of the bottom of the rice cooking pot 6. A lid thermistor 15 is provided to detect the temperature inside the rice cooker 6 by coming into contact therewith, and detection signals from the thermistors 14 and 15 can be input to the controller 20 .

The controller 20 is installed below the rice cooker 6 and the burner 8 and performs opening/closing control of the main solenoid valve 11 and the first and second solenoid valves 12 and 13 and ignition control of the burner 8 . The controller 20 includes an arithmetic unit 21 that performs various arithmetic processing using a CPU, a storage unit 22 that stores a cooking program, a frequency fluctuation table described later, and the like using ROM, RAM, EEPROM, etc., and a crystal oscillator. A clock unit 23 for clocking the current time by accumulating the number of clock counts from a crystal oscillator and a battery (not shown) are provided and electrically connected to the operation panel 4 .

The operation panel 4 includes a display screen 25 consisting of a 7-segment display, a menu button 26 for selecting cooking menus other than normal rice cooking such as cake cooking and rice porridge cooking, a keep warm button 27 for switching on/off of keep warm, timer rice cooking and the like. A time setting button 28 for setting timer cooking and the current time, a reservation button 29 for reserving timer cooking, etc., a start button 30 for starting cooking, and a cancel button 31 for canceling the menu input with each button are provided.
Therefore, when a cooking menu is selected by operating the operation panel 4 and the start button 30 is turned on, the controller 20 detects by the kettle thermistor 14 and the lid thermistor 15 based on the cooking program corresponding to the cooking menu. By monitoring the temperature, the electromagnetic valves 11 to 13 are opened and closed to control the combustion of the burner 8, and the energization of the kettle heater 9 and lid heater 10 is controlled to perform the selected cooking.

In addition, the controller 20 counts the number of clocks counted by the timer unit 23 only under a predetermined condition at a predetermined time (for example, midnight) or at predetermined time intervals while power is being supplied from the power plug. can be corrected to correct the current time. This condition is
(1) When the temperature difference between the kettle thermistor 14 and the lid thermistor 15 is within a predetermined temperature (for example, 10° C.).
(2) When the detected temperature of the pot thermistor 14 is 40° C. or less.
is.

Here, the temperature difference between the pot thermistor 14 and the lid thermistor 15 in (1) is used as a condition because, for example, when a short time has passed since the end of rice cooking (for example, within 3 hours), the pot thermistor 14 and the lid thermistor 15, the difference from the current time is increased if the clock count number is corrected based on the detected temperature from one of the thermistors.
The reason why the temperature detected by the pot thermistor 14 is used as a condition in (2) is that the controller 20 is arranged below the rice cooker 6 so that the crystal oscillator of the timer unit 23 and the pot thermistor 14 are in the same temperature environment. The reason why the upper limit temperature of 40° C. is set as a condition is that the temperature of the crystal oscillator, which is the same temperature environment as that of the pot thermistor 14, is high. This is to avoid

Therefore, when the temperature difference between the pot thermistor 14 and the lid thermistor 15 is within a predetermined temperature range and the detected temperature of the pot thermistor 14 is 40° C. or less, the controller 20 stores the detected temperature of the pot thermistor 14 and the storage unit 22. Using the stored frequency fluctuation table, the number of clocks counted from the crystal oscillator in the timing unit 23 is corrected at a predetermined timing (for example, the number of clocks is added or subtracted from the number of clocks per second). Become. However, when operating on a battery with a power failure or with the power plug unplugged, correction of the clock count is not performed even if the above conditions (1) and (2) are satisfied.
The frequency variation table is set, for example, as shown in Table 1 below. The left column of the table shows the detected temperature (temperature range) of the pot thermistor 14, and the right column shows the correction time (seconds) per day corresponding to the temperature range. The number of clocks to be corrected from this correction time is calculated by the calculating section 21 and corrected by the timer section 23 .

In setting the correction time here, the correction time is set to 0 in the temperature range of 11.4° C. to 15.0° C. and in the temperature range of 35.0° C. to 38.6° C., and 21.0° C. between the two temperature ranges. The correction time decreases as the temperature goes from 6°C to 28.4°C. Conversely, the correction time increases as the temperature decreases from 11.4°C to 15.0°C, and the correction time also increases when the temperature increases from 35.0°C to 38.6°C. ing. That is, as shown in FIG. 3, the correction characteristic is similar to a shape that curves downward as a whole.
The dotted line in the figure is the correction characteristic of the crystal oscillator according to the invention described in the aforementioned Patent Document 1. FIG. Before the correction, the error was 0 when the temperature was 25°C, and the error increased as the temperature deviated from 25°C. It has a shape. On the other hand, in the present embodiment, since the correction characteristic is such that the curve swells downward, the error due to the temperature change is effectively canceled.

As described above, according to the gas rice cooker 1 of the above-described embodiment, the controller 20 (control means) operates when the temperature difference between the pot thermistor 14 (bottom temperature sensor) and the lid thermistor 15 (internal temperature sensor) is within a predetermined temperature. , the current time is corrected by correcting the clock count number from the crystal oscillator using the temperature detected by the kettle thermistor 14 and the frequency variation table in which the correction time for the clock count number corresponding to the detected temperature is preset. Correction can be avoided when the temperature difference between the thermistor 14 and the lid thermistor 15 is large. Therefore, it is possible to provide a highly reliable timekeeping function by reducing time lag.

Especially here, the controller 20 is provided below the rice cooker 6 and the burner 8, and when the difference between the detected temperatures of the kettle thermistor 14 and the lid thermistor 15 is within a predetermined temperature, the controller 20 controls the detected temperature of the kettle thermistor 14. and the frequency variation table, the clock count can be corrected more accurately based on the detected temperature of the pot thermistor 14 which is in the same temperature environment as the crystal oscillator.
Further, when the detected temperature of the pot thermistor 14 is lower than the predetermined temperature, the controller 20 uses the detected temperature of the pot thermistor 14 and the frequency variation table, so the temperature of the crystal oscillator, which is in the same temperature environment as the pot thermistor 14, is high. It is possible to avoid corrections in the state.

Note that the difference in detected temperature between the kettle thermistor and the lid thermistor when correcting the clock count, and the upper limit temperature when using the detected temperature of the kettle thermistor are not limited to the numerical values in the above form, and can be changed as appropriate. . The temperature range and correction time of the frequency variation table can also be changed as appropriate.
Moreover, in the above embodiment, the controller is arranged below the rice cooker and the burner, but the controller may be arranged at another location. In this case, the temperature detected by the lid thermistor may be used to correct the clock count, and the upper limit temperature of the pot thermistor may not be used as a correction condition.
Furthermore, it is possible to change the design such that a plurality of thermistors are used instead of one thermistor for each of the bottom surface temperature sensor and the internal temperature sensor, and the average detected temperature is used. Sensors other than thermistors can also be employed.

DESCRIPTION OF SYMBOLS 1... Gas rice cooker, 2... Main body, 3... Lid body, 4... Operation panel, 5... Gas pipe. 6 Rice cooker 7 Inner lid 8 Burner 11 Main solenoid valve 12 First solenoid valve 13 Second solenoid valve 14 Pot thermistor 15 Lid Thermistor 20 Controller 21 Arithmetic unit 22 Storage unit 23 Clock unit 25 Display screen.

Claims (1)

A rice cooker with an open top,
a lid that closes the opening of the rice cooker;
a burner for heating the rice cooker from below;
a bottom temperature sensor that detects the bottom temperature of the rice cooker;
an internal temperature sensor that is provided on the lid and detects the internal temperature of the rice cooker;
control means for controlling combustion of the burner based on the temperatures detected by the bottom surface temperature sensor and the internal temperature sensor, the control means having a timekeeping function for measuring the current time based on the number of clock counts from a crystal oscillator;
a power cord having a power plug, the gas rice cooker comprising:
The control means is provided below the rice cooker and the burner,
When the temperature difference between the bottom surface temperature sensor and the internal temperature sensor is within a predetermined temperature while power is being supplied from the power plug , the control means detects a temperature detected by the bottom surface temperature sensor. 2, the clock count from the crystal oscillator is performed using the temperature detected by the bottom surface temperature sensor and a frequency variation table in which the correction time for the clock count number corresponding to the detected temperature is preset. A gas rice cooker characterized by correcting a current time by correcting a number.

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