JP3287741B2 - Jar rice cooker - Google Patents

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.

[0002]

2. Description of the Related Art In a conventional jar rice cooker, electric power supplied to a heater as heating means for cooking rice is as follows.
Since the power varies depending on the power supply voltage, the microcomputer of the control unit needs to execute the rice cooking sequence in accordance with the electric power supplied to the heater in order to obtain an optimal rice cook. Therefore, the power supplied to the heater is identified by detecting the voltage value of the power supply, and a rice cooking sequence for obtaining an optimal rice cook has been executed.

FIG. 11 is a circuit diagram of a conventional jar rice cooker, and FIG. 12 is a flowchart showing an operation of a microcomputer of the conventional jar rice cooker. In FIG. 11, reference numeral 51 denotes an AC power supply. The AC power supply 51 includes a heater 52 for heating at least a pot in which water and rice are put, and a relay contact 53 of a relay 53.
The relay circuit 53a is connected and opened (ON, OFF) by passing a current through the relay coil 53b via the resistor 66 and the transistor 67 by a signal from the output port of the microcomputer 60. ing. Note that the resistor 66 and the transistor 67 constitute a relay drive circuit.

A primary side of a transformer 54 is connected to an AC power supply 51.
And its secondary side is connected to the rectifying bridge 55. Reference numeral 56 denotes an electrolytic capacitor for smoothing the voltage rectified by the rectifying bridge 55. And 6
8 and 69 are rectifier bridge 55 and electrolytic capacitor 56
The resistors 68 and 69 are connected to the input port of the microcomputer 60. With the above configuration, the voltage value of the AC power supply 51 that supplies power to the heater 52 is indirectly detected.

The voltage detected as described above is applied to the microcomputer 6
0, the microcomputer 60 compares the voltage value stored in advance in the memory with the detected voltage value, and determines whether the power supply voltage is equal to or higher than the rated value (the power supplied to the heater 52). ), The duty ratio of the heater 52 is controlled by the ON-OFF duty of the relay 53. The resistor 57, the constant voltage diode 58 and the transistor 59 are provided to stabilize the voltage supplied to the relay coil 53b of the relay 53 and the voltage supplied to the microcomputer 60.

[0006] 64 is a thermistor for detecting the temperature of the pot,
Reference numeral 65 denotes a voltage dividing resistor for the thermistor 64, and a temperature signal is input to the microcomputer 60 by a voltage divided by the thermistor 64 and the resistor 65. Reference numeral 61 denotes a key switch for starting rice cooking.
Is connected to the input port of the microcomputer 60 so that it can be determined whether or not is pressed. Reference numeral 70 denotes a display unit for displaying that reading of voltage detection has been completed by a signal from an output port of the microcomputer 60. In addition, 62 is a key switch for stopping rice cooking or heat retention, and 63 is a key switch for executing heat retention.

The operation of the jar rice cooker constructed as described above will be described with reference to the flowchart of FIG. First, rice cooking is started by pressing the key switch 61 (S51), and the microcomputer 60 executes a rice cooking sequence (S52). Subsequently, according to a signal from the output port of the microcomputer 60, a current flows through the relay coil 53b through the resistor 66 and the transistor 67, and the relay contact 53
is closed and the relay 53 is turned on (S53). Thus, the heater 52 is energized (S54) to heat the pot.

Then, the voltage output to the secondary side of the transformer 54 is rectified by a rectification circuit composed of a rectification bridge 55 and an electric field capacitor 56, and then divided by resistors 68 and 69, and Indirectly detects the voltage value of the power supply that supplies power to the power supply. The signal of the detected voltage is input to the microcomputer 60, and the microcomputer 60 compares the voltage value stored in the memory with the detected voltage value to determine whether the power supply voltage is equal to or higher than the rated value. Is determined (S55).

In step 55 (S55), the microcomputer 60
Determines that the power supply voltage is equal to or higher than the rated value (YE
S), the power supply rate to the heater 52 is reduced (S56).
On the other hand, when the microcomputer 60 determines that the power supply voltage is lower than the rated value (NO), the microcomputer 60 increases the duty ratio of the heater (S
57).

Next, a signal of the temperature of the pan detected by the thermistor 64 is input to the microcomputer 60,
Determines whether the temperature of the pot has reached or exceeds the rice cooking temperature (120 ° C.) (S58). Step 58 (S5
In step 8), when the microcomputer 60 determines that the temperature of the pot is lower than 120 ° C. (NO), steps S55 to S57 are repeated until the temperature of the pot reaches or exceeds the rice cooking temperature. On the other hand, when the microcomputer 60 determines that the temperature of the pan is equal to or higher than 120 ° C. (YES), the microcomputer 60 executes the spotting mode (S5).
9) Then, the rice cooking is finished (S60).

[0011]

However, according to the above-mentioned conventional jar rice cooker, commercial jar rice cookers are used as voltage detecting means for detecting the voltage value of a power supply for supplying power to a heater which is a heating means for cooking rice. Since the power supply voltage was indirectly detected based on the secondary output voltage of the transformer that transforms the power supply voltage and supplies the secondary voltage to the control unit, errors in the transformer and its peripheral circuits were detected. However, there is a problem that the error is large and a larger error is generated.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to provide a jar rice cooker in which an error of a means for detecting electric power supplied to a heater as a heating means is minimized. With the goal.

[0013]

A first gist of the present invention is as follows .
A pan for at least rice and water, a heating unit for heating the pan, a temperature detection unit for detecting the temperature of the pan, and control for controlling the heating unit based on the temperature detected by the temperature detection unit. And a voltage detecting means for detecting a voltage value of a power supply for supplying power to the heating means.
A reference value, which is a rating of the voltage value of the power source, is previously set in the control unit.
The internal or external memory of the
A voltage detection setting mode to be stored is provided, and the control unit
It is characterized by correcting rice cooking sequence by reference value
Jar rice cooker.

[0014] A second gist of the present invention is that a pot containing at least rice and water, heating means for heating the pot, temperature detecting means for detecting the temperature of the pot, and temperature detected by the temperature detecting means. A jar rice cooker comprising a control unit for controlling the heating means based on the temperature detected, and voltage detection means for detecting a voltage value of a power supply for supplying power to the heating means, wherein the voltage detection means is directly In order to detect the voltage value of the power supply, one phase on the primary side where the power supply is located and the secondary side where the voltage detecting means is connected, and the control unit detects the voltage directly detected by the voltage detecting means. A rice cooker characterized in that a rice cooking sequence is corrected based on a voltage value of a power supply.

A third gist of the present invention is that a pot containing at least rice and water, heating means for heating the pot, temperature detecting means for detecting the temperature of the pan, and temperature detected by the temperature detecting means. A control unit that controls the heating unit based on the temperature, and a current detection unit that detects a current value of a power supply that supplies power to the heating unit, wherein the heating unit is connected in series. While connected to a resistor, the power supply connects a single-phase on the primary side with the current detection means to the secondary side, and the control unit performs the rice cooking sequence based on the voltage value of the voltage drop of the resistor. A jar rice cooker characterized by performing a correction.

[0016]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a block diagram of a first embodiment of a jar rice cooker according to the present invention. In FIG. 1, reference numeral 1 denotes a pot which is detachably housed in a jar rice cooker main body and at least puts rice and water, and 2 denotes a heater provided in the jar rice cooker main body for heating the pan 1 to cook and keep warm. 3 is a power supply for supplying power to the heater 2, 4 is a temperature detecting means for detecting the temperature of the pan 1, 6 is a voltage detecting means for detecting the voltage of the power supply 3, 5 is a signal from the temperature detecting means 4 and a voltage detecting means. 6 on the basis of the signal from
The control unit includes a microcomputer that performs N.OFF control and executes a rice cooking sequence.

FIG. 2 is a circuit diagram of the first embodiment of the jar rice cooker according to the present invention, and FIG. 3 is a flowchart showing the operation of the microcomputer of the first embodiment of the jar rice cooker according to the present invention. In FIG. 2, reference numeral 11 denotes an AC power supply. A series circuit of a heater 12 for heating at least a pot for putting water and rice and a relay contact 13a of a relay 13 is connected to the AC power supply 11, and a signal from an output port of the microcomputer 20 is provided. A current flows through the relay coil 13b through the resistor 26 and the transistor 27, thereby forming the relay contact 13a.
Are opened and closed (ON, OFF). In addition,
The resistor 26 and the transistor 27 constitute a relay drive circuit.

The primary side of the transformer 14 is connected to the AC power supply 11.
And its secondary side is connected to the rectifying bridge 15. Reference numeral 16 denotes an electrolytic capacitor for smoothing the voltage rectified by the rectifying bridge 15. And 2
8 and 29 are rectifier bridge 15 and electrolytic capacitor 16
The resistors 28 and 29 are connected to the input port of the microcomputer 20.

A reference value, which is a rating of a voltage value of a power supply for supplying electric power to the heater 12, is stored in an internal memory of a storage unit of the microcomputer 20, which comprises a resistor 30, a diode 31, and a backup power supply 32. Are stored in advance. The voltage corresponding to this rated value is
4 and the transformed voltage is output to the secondary side of the transformer 14. The voltage output to the secondary side of the transformer 14 is rectified by the rectifier circuit including the rectifier bridge 15 and the electric field capacitor 16 as described above. Resistance 1
7. The constant voltage diode 18 and the transistor 19 are provided to stabilize the voltage supplied to the relay coil 13b of the relay 13 and the voltage supplied to the microcomputer 20.

When a current flows through the relay coil 13b to turn on the relay 13, the voltage output to the secondary side of the transformer 14 drops. At this time, the voltage rectified by the rectifier circuit is divided by the resistors 28 and 29, whereby the voltage value of the AC power supply 11 that supplies power to the heater 12 is indirectly detected. The microcomputer 20
To enter.

Reference numeral 24 denotes a thermistor for detecting the temperature of the pot.
Reference numeral 25 denotes a voltage dividing resistor for the thermistor 24, and a temperature signal is input to the microcomputer 20 by a voltage divided by the thermistor 24 and the resistor 25. Reference numeral 21 denotes a key switch for starting rice cooking.
Is connected to the input port of the microcomputer 20 so that it can be determined whether or not is pressed. Reference numeral 33 denotes a display unit for displaying that reading of voltage detection has been completed by a signal from an output port of the microcomputer 20. In addition, 22 is a key switch for stopping rice cooking or heat retention, and 23 is a key switch for executing heat retention.

The operation of the jar rice cooker configured as described above will be described with reference to the flowchart of FIG. First, in step 11 (S11), a reference value which can be set in advance in the production process and is a rated value of a voltage value of a power supply for supplying power to the heater 12 is stored in the microcomputer 20 .
A mode for storing data in the internal memory is provided, and the voltage of the power supplied to the circuit is adjusted to the rated value.

In step 12 (S12), the key switch 2
It is determined whether or not the mode has been executed according to 1 to 23, and if the mode has been executed (YES),
Proceeding to step 13 (S13), the transistor 27 is turned on by the signal from the microcomputer 20, and the relay 13 is turned on.
It becomes N. Therefore, electric power is supplied to the heater 12.

Next, in step 14 (S14), the voltage rectified by the rectifier circuit is indirectly detected by the voltage division of the resistors 28 and 29, and it is determined whether or not the microcomputer 20 has read the detected voltage. Steps 13 and 14 are repeated until the reading of the detection is completed. If the reading of the voltage detection is completed (YES), step 15 (S
In step 15), the reading of the voltage detection is completed on the display 33.
Displays the door, the flow proceeds to step 16 (S16), it enters the normal operation mode. It should be noted that, even if the voltage detection setting mode has not been set in step 12 (S12) (NO), the process proceeds to step 16 (S16), and the operation mode is set to the normal operation mode.

A second embodiment of the jar rice cooker according to the present invention will be described with reference to FIGS. The block diagram of the second embodiment of the jar rice cooker according to the present invention is the same as the block diagram of the first embodiment shown in FIG. 1, and the description thereof will be omitted here.

FIG. 4 is a circuit diagram of a second embodiment of the jar rice cooker according to the present invention, and FIG. 5 is a flowchart showing the operation of the microcomputer of the second embodiment of the jar rice cooker according to the present invention. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted. Unlike the first embodiment in which an internal memory is provided in the microcomputer 20 to store in advance in the production process a reference value that is a rating of the voltage value of the power supply 11 that supplies power to the heater 12, unlike the first embodiment. The microcomputer 20 is provided with an external memory 34 (E ² ROM) for storing a reference value, which is a rating of the voltage value of the power supply 11 that supplies power to the heater 12, in advance in the production process.

The operation of the jar rice cooker configured as described above will be described with reference to the flowchart of FIG. First, in step 21 (S21), there is provided a mode in which a reference value, which can be set in advance in the production process and is a voltage value of a power supply for supplying power to the heater 12, is stored in the external memory 34 of the microcomputer 20. Adjust the power supply voltage to the rated value. Step 22 (S2
At 2), it is determined whether or not the mode is executed by the key switches 21 to 23. If the mode is executed (YES), the process proceeds to step 23 (S23), and the transistor 27 is turned on by a signal from the microcomputer 20. And the relay 13 is turned on. Therefore, electric power is supplied to the heater 12.

Next, in step 24 (S24), the voltage rectified by the rectifier circuit is indirectly detected by the voltage division of the resistors 28 and 29, and it is determined whether or not the microcomputer 20 has read the detected voltage. Steps 23 and 24 are repeated until the reading of the detection is completed. If the reading of the voltage detection is completed (YES), step 25 (S
In step 25), the data is transferred to the external memory (E2ROM) 34 and stored therein. Then, in step 26 (S26), it is determined whether or not the external memory (E2ROM) has read the detected data, and steps 25 and 26 are repeated until the reading of the data is completed. Step 26
When the reading of the data from the external memory (E2ROM) 34 is completed in (S26) (YES), step 27 is performed.
Displays that you read the voltage detection has been completed on the display unit 33 in (S27), step 28 proceeds to (S28), enters the normal operation mode. Note that, even if the voltage detection setting mode has not been set in step 22 (S22) (NO), the process proceeds to step 28 (S28), and the operation mode is set to the normal operation mode.

A third embodiment of the jar rice cooker according to the present invention will be described with reference to FIGS. The block diagram of the third embodiment of the jar rice cooker according to the present invention is the same as the block diagram of the first embodiment shown in FIG. 1, and thus the description thereof is omitted here.

FIG. 6 is a circuit diagram of a third embodiment of the jar rice cooker according to the present invention, and FIG. 7 is a flowchart showing the operation of the microcomputer of the third embodiment of the jar rice cooker according to the present invention. In the third embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted. The difference from the first embodiment is that, as shown in the circuit diagram of FIG. 6, a primary side of a power supply 11 for supplying power to a heater 12 and a secondary side resistor 29 for detecting a voltage are connected. And resistors 28 and 2
Reference numeral 9 is connected to an input port of the microcomputer 20 via a diode 35. As a result, the voltage of the commercial power supply 11 can be directly divided and detected by the resistors 28 and 29, and the detected voltage can be input to the microcomputer 20.

The operation of the jar rice cooker configured as described above will be described with reference to the flowchart of FIG. As a rice cooking sequence of the jar rice cooker, first, rice cooking is started by the key switch 21 in step 30 (S30), and the microcomputer 20 executes the rice cooking sequence in step 31 (S31). Next, step 32 (S
32) In order to supply electric power to the heater 12 in
, A relay drive circuit including a resistor 26 and a transistor 27 is driven, the relay 13 is turned on,
In step 33 (S33), the heater 12 is energized.

At this time, as voltage detecting means for detecting the voltage value of the power supply 11 for supplying power to the heater 12, the voltage of the commercial power supply 11 is directly divided by the resistors 28 and 29 and detected. In step 34 (S34), the detected voltage is input to the microcomputer 20 and compared with a voltage detection value stored in the microcomputer 20 in advance.
To determine whether the voltage supplied to the
If the power supply voltage is equal to or higher than the rated value (YES), step 3
Proceeding to 5 (S35), the energization rate of the heater 12 increases. On the other hand, if the power supply voltage is lower than the rated value (NO), the process proceeds to step 36 (S36), and the duty ratio of the heater 12 decreases.
That is, the duty ratio of the heater 12 is set to the ON-O
It is adjusted by the duty of FF.

Subsequently, in step 37 (S37), the temperature of the pot is input to the microcomputer 20 by the thermistor 24, and it is determined whether or not the temperature has reached the cooking temperature of rice (120 ° C.). Steps 34-3 until it reaches
Repeat 6. When the rice cooking temperature (120 ° C.) has been reached (YES), the rice cooker terminates the rice cooking in step 39 (S39) after executing the fly mode in step 38 (S38).

A fourth embodiment of the jar rice cooker according to the present invention will be described with reference to FIGS. FIG. 8 is a block diagram of a first embodiment of a jar rice cooker according to the present invention. In FIG. 8, reference numeral 1 denotes a pot that is detachably housed in a jar rice cooker main body and that contains at least rice and water;
A heater provided in the jar rice cooker main body for heating rice, and for performing rice cooking and heat retention, 3 is a power supply for supplying electric power to the heater 2, 4 is a temperature detecting means for detecting the temperature of the pan 1, 7 is a power supply 3 A current detection means 5 for detecting the current of the heater 5 is a control unit including a microcomputer for controlling ON / OFF of the heater 2 based on a signal from the temperature detection means 4 and a signal from the current detection means 6 and executing a rice cooking sequence. is there.

FIG. 9 is a circuit diagram of a fourth embodiment of the jar rice cooker according to the present invention, and FIG. 10 is a flowchart showing the operation of the microcomputer of the fourth embodiment of the jar rice cooker according to the present invention. In the fourth embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted. The difference from the first embodiment is that, as shown in the circuit diagram of FIG. 9, a resistor 36 is connected in series to the heater 12, and a power supply 11 for supplying power to the heater 12 is provided on the primary side of the circuit. One phase is directly connected to the input port of the microcomputer 20 on the secondary side of the circuit. As a result, the microcomputer 20 detects the resistance 3 directly detected.
The current value of the power supply 11 supplied to the heater 12 can be detected based on the voltage value corresponding to the voltage drop of 6, and the rice cooking sequence can be corrected.

The operation of the jar rice cooker configured as described above will be described with reference to the flowchart of FIG. As a rice cooking sequence of the jar rice cooker, first, rice cooking is started by the key switch 21 in step 40 (S40), and the microcomputer 20 is started in step 41 (S41).
To execute the rice cooking sequence. Next, step 42
In step (S42), a relay drive circuit including a resistor 26 and a transistor 27 is driven by a signal from the microcomputer 20 to supply power to the heater 12, the relay 13 is turned on, and the heater 12 is energized in step 43 (S43). I do.

At this time, the resistor 36 serves as current detecting means for detecting the current value of the power supply 11 for supplying power to the heater 12.
Is directly detected. Step 44
In step (S44), the voltage detected in this manner is input to the microcomputer 20 and compared with a current detection value stored in the microcomputer 20 in advance to determine whether the current supplied to the heater 12 is higher than the rated value. It is determined whether or not the power supply current is equal to or higher than the rated value (YES), and the process proceeds to step 45 (S45) to increase the duty ratio of the heater 12. On the other hand, if the power supply current is less than the rated value (NO), the process proceeds to step 46 (S46), and the duty ratio of the heater 12 decreases. That is, the duty ratio of the heater 12 is adjusted by the ON / OFF duty of the relay 13.

Subsequently, in step 47 (S47), the temperature of the pot is input to the microcomputer 20 by the thermistor 24, and it is determined whether or not the temperature has reached the rice cooking temperature (120 ° C.). Steps 44-4 until it reaches
Repeat 6. When the rice cooking temperature (120 ° C.) has been reached (YES), the rice cleaning mode is executed in step 48 (S48), and the rice cooking is terminated in step 49 (S49).

[0039]

According to a first aspect of the rice cooker of the present invention, in the production process, electrostatic power supplies power to the heating means
The reference value is a rating of the pressure value, by storing the internal memory or external memory of the microcomputer provided in the control portion, it is possible to correct variations in circuit components of the voltage detecting means, a stored value The rice cooking sequence can be corrected, and a rice cooking sequence for obtaining optimal rice cooking can be executed.

According to the jar rice cooker according to the second aspect of the present invention, as a circuit of the voltage detecting means for detecting the voltage value of the power supply for supplying electric power to the heating means, the primary side one phase and the secondary side are connected. By connecting, it is possible to directly detect the voltage value of the primary-side power supply which is a power supply for supplying power to the heating means, and to reduce a detection error of the voltage value of the power supply for supplying power to the heating means, The control unit corrects the rice cooking sequence based on the directly detected voltage value, and can execute the rice cooking sequence for obtaining optimal rice cooking.

According to the jar rice cooker of the third aspect of the present invention , a resistor is connected in series to the heating means, and the circuit of the current detection means for detecting the current value of the power supply for supplying power to the heating means is provided. By connecting the primary side one phase and the secondary side, the current value of the primary side power supply supplied to the heating means is heated by the voltage value of the voltage drop of the resistor connected in series to the heating means. The detection error of the value of the current supplied to the means can be kept small, and the control unit corrects the rice cooking sequence by the voltage value of the voltage drop of the resistor connected in series with the heating means, and obtains the optimal rice cooking. Rice cooking sequence can be executed.

[Brief description of the drawings]

FIG. 1 is a block diagram of first, second and third embodiments of a jar rice cooker according to the present invention.

FIG. 2 is a circuit diagram of a first embodiment of a jar rice cooker according to the present invention.

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

FIG. 4 is a circuit 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 second embodiment of the rice cooker according to the present invention.

FIG. 6 is a circuit diagram of a third embodiment of the jar rice cooker according to the present invention.

FIG. 7 is a flowchart showing an operation of the microcomputer of the third embodiment of the rice cooker according to the present invention.

FIG. 8 is a block diagram of a fourth embodiment of a jar rice cooker according to the present invention.

FIG. 9 is a circuit diagram of a fourth embodiment of a jar rice cooker according to the present invention.

FIG. 10 is a flowchart showing the operation of the microcomputer of the fourth embodiment of the rice cooker according to the present invention.

FIG. 11 is a circuit diagram of a conventional jar rice cooker.

FIG. 12 is a flowchart showing an operation of a microcomputer of the conventional jar rice cooker.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pot 2 Heater 3 Power supply 4 Temperature detection means 5 Control part 6 Voltage detection means

Claims (1)

(57) [Claims] 1. A pan for at least rice and water, a heating unit for heating the pan, a temperature detection unit for detecting a temperature of the pan, and the heating based on a temperature detected by the temperature detection unit. A jar rice cooker comprising a control unit for controlling means and a current detection means for detecting a current value of a power supply for supplying power to the heating means, wherein the heating means is connected to a resistor in series, One phase on the primary side where the power source is located and the secondary side where the current detecting means is located are connected, and the control unit corrects the rice cooking sequence based on the voltage value of the voltage drop of the resistor. Jar rice cooker.