JPS6135843B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a rice cooker, and in particular, it is an object of the present invention to provide a rice cooker that can automatically double-cook rice while preventing it from emitting noise or malfunctioning due to a temporary power outage. It is.

In the rice cooking method known as "double cooking" or "additional cooking," when the moisture at the bottom of the rice cooker's pot is absorbed into the rice and the temperature at the bottom of the pot rises, a heat-responsive switch is opened and electricity is turned on to the heating element for rice cooking. After that, when the temperature at the bottom of the pot drops a little, the rice heating element is energized again to reheat the rice. According to this rice cooking method, it has been confirmed that the moisture attached around the rice grains is evaporated or absorbed into the rice by reheating, improving the flavor, texture, and taste.

However, with conventional rice cookers, you have to wait until the time is right to cook twice and then manually turn the switch on again.
It has the disadvantage that it has to be turned on, making it inconvenient to handle, and devices that have a built-in microcomputer to perform this operation are expensive and impractical.

The present invention solves the drawbacks of the conventional rice cooker described above, and embodiments of the present invention will be described below with reference to the accompanying drawings.

In the figure, 1 is a heating element for cooking rice, 2 is a heat-responsive switch that senses the temperature at the bottom of the pot and opens the pot.
The heating element 1 for rice cooking and the thermally responsive switch 2 are connected in series. 3 is a timer that starts operating when the thermally responsive switch 2 is opened, and 4 is a switch that can be set to forcibly block the supply of electricity to the timer 3. The serial connection of the timer 3 and switch 4 is It is connected in parallel to the response switch 2. 5 is a solenoid that is energized and driven after a certain period of time after the timer 3 starts energizing;
The thermal response switch 2 is activated by driving this solenoid 5.
is configured to reclose.

The specific circuit configuration is as shown in FIG.
are connected in series, and the Zener diode 7 is connected to a capacitor 8, a series connection body of a resistor 9, a resistor 10, and a capacitor 11, a series connection body of a resistor 12 and a resistor 13,
The series-connected bodies of the solenoid 5 and the thyristor 14 are connected in parallel. 15 is PUT, and the anode electrode is the connection point a between resistor 9 and resistor 10.
The gate electrode is connected to the connection point b between the resistors 12 and 13, and the cathode electrode is connected to the resistor 16.

Further, the structural relationship among the thermally responsive switch 2, switch 4, and solenoid 5 is as shown in FIGS. 3 and 4.

That is, 16 is a center thermostat, which senses the temperature at the bottom of the pot and rotates the rice cooking lever 17. A thermally responsive switch 2 is provided below the rice cooking lever 17, and when its actuator is pressed by the rice cooking lever 17, it opens its contacts. 18 is a double-cooking lever, and a switch 4 is provided below this double-cooking lever 18, and when its actuator is pressed by the double-cooking lever 18, the contact point is opened. 1
A spring 9 biases the double-cooking lever 18 in the direction of pressing the actuator of the switch 3. 20 is a rice cooking button provided on the rice cooking lever 17, and 21 is a double cooking button provided on the double cooking lever 18. The solenoid 5 is the main body 22
Fixed. A rod 23 is attracted by the solenoid 5 and moves downward when the solenoid 5 is energized, and is urged upward by a spring 24 when the solenoid 5 is not energized. The rod 23 is integrally provided with a hook 25 that protrudes inward, and when the double-cooking button 21 is pressed downward, the hook 26, which is a bent part of the double-cooking lever 18, is hooked onto this hook. It engages with the metal fitting 25 and holds the double-cooking lever 18 in a state where the actuator of the switch 4 is pressed against the biasing force of the spring 19.

Next, a rice cooking method with the above configuration will be explained.

First, when the rice cooking button 20 is pressed downward, the suction action of the center thermostat 16 causes the rice cooking lever 1 to
7 is maintained in a state in which the actuator of the thermally responsive switch 2 is not pressed. Therefore, the thermal response switch 2 closes the contact, the power supply voltage is applied to the heating element 1 for rice cooking, and the temperature of the pot rises. Next, when the double-cooking button 21 is pressed, the double-cooking lever 18
The hook portion 26 engages with the hook 25 of the rod 23, and due to this engagement, the double-cooking lever 18 is maintained in a state in which the actuator of the switch 4 is released against the biasing force of the spring 19. . Therefore, the contacts of switch 4 are closed. Note that the order of operation of the rice cooking button 20 and the double cooking button 21 may be reversed. The temperature of the pot rises by energizing the heating element 1 for rice cooking, and when the bottom temperature of the pot reaches point A shown in FIG. The contact of the thermally responsive switch 2 that was pressed is opened. By opening this contact, a power supply voltage is applied to the timer 3, and the timer 3 starts operating. At this time, due to the engagement between the hook 25 and the hook 26, the double-cooking lever 18 is not pressing the actuator of the switch 4, and the contact of the switch 4 remains closed. The operation of timer 3 is as follows. First, connect capacitor 8 through diode 6.
Then, it is charged to a voltage regulated by the Zener diode 17. From this point on, the capacitor 11 is gradually charged through the resistors 9 and 10, and after a certain period of time,
For example, after 5 minutes, the PUT 15 is turned on when the potential at point a becomes higher than the potential at point b. PUT15
The electric charge charged in capacitor 11 due to ON is
It flows into the gate pole of the thyristor 14 via the PUT 15, turning the thyristor 14 ON. When the thyristor 14 is turned on, the electric charge stored in the capacitor 8 flows to the solenoid 5 and is discharged. At this time, the solenoid 5 attracts and lowers the rod 23 against the biasing force of the spring 24 due to the electric charge, that is, the current flowing through the solenoid 5. In addition, solenoid 5
The current that flows through the device only needs to flow for an extremely short period of time, and a large output can be obtained instantaneously without considering the self-heating amount. However, if the time that the current flows through the solenoid 5 is too short, the actual force may not be generated due to inertia even if a large output can be obtained, and the impedance of the solenoid 5 and the capacity of the capacitor 8 By appropriate selection of the voltages determined by the Zener diodes 7, it is possible to generate very large forces.

When current flows through this solenoid 5,
When the rod 23 descends, the hook 25 integrated with the rod 23 also descends, and the hook 25 and the hook 26
is disengaged, and the double-cooking lever 18 is rotated by the biasing force of the spring 19 in the direction of pressing the actuator of the switch 4. That is, the contacts of the switch 4 are opened, and the timer 3 is no longer energized. On the other hand, as the rod 23 descends, the rice cooking lever 17 is pressed against the lower end of the rod 23, closing the contact of the thermally responsive switch 2 (point B in FIG. 5).

Thereafter, a power supply voltage is applied to the heating element 1 for rice cooking, and the temperature of the pot rises. When the pot temperature reaches point C in Figure 5, the center thermostat 16 moves away again, the rice cooking lever 17 rotates, and the heat response switch 2
The actuator is pressed to open the contact of the thermally responsive switch 2 and rice cooking is completed.

In the above embodiment, an electric rice cooker has been described, but it goes without saying that the present invention can also be applied to a gas rice cooker by using the rice cooking heater 1 as a gas heat source and using the thermally responsive switch 2 to open and close the gas valve.

Further, the timer 5 may be a clockwork type timer instead of an electronic circuit.

As is clear from the above description, according to the present invention, there is a heat-responsive switch that is connected in series with a rice-cooking heating element and opens by sensing the temperature at the bottom of the pot, and the operation starts when the heat-responsive switch is opened. and a solenoid that is driven by the timer after a certain period of time, and when the solenoid is driven, the switch is opened to forcibly stop the power supply to the timer, and the thermally responsive switch is closed again. Therefore, if the user needs to cook additional rice, he/she can simply operate the double-cooking lever when starting rice cooking, and the rice-cooking mode will automatically start after a certain period of time after the first rice is cooked. Since the heating element is re-energized, the user does not have to operate the rice cooking lever again when the first rice is cooked, and can perform double cooking, or additional cooking. By employing a switch that forcibly stops energization, the rice cooker is extremely easy to use, as the rice cooking time does not become longer than necessary, since the operation is performed only once.

[Brief explanation of the drawing]

Fig. 1 is a schematic electrical circuit diagram of a rice cooker showing an embodiment of the present invention, Fig. 2 is a specific electrical circuit diagram of the rice cooker, Fig. 3 is a side view of main parts of the rice cooker, and Fig. 4 The figure is a side view of the same main part showing the operation state of the double-cooking lever 18 of the same rice cooker, and FIG. 5 is a diagram showing the change in pot temperature over time by the same rice cooker. 1...Heating element for rice cooking, 2...Heat-responsive switch,
3...Timer, 5...Solenoid.

Claims (1)

[Claims] 1. A heat-responsive switch that senses the temperature at the bottom of the pot and opens the pot, a heating element for cooking rice that is connected in series to this heat-responsive switch, a timer that starts operating when the heat-responsive switch is opened, and a timer that starts operating when the heat-responsive switch is opened. and a solenoid that is driven after a certain period of time, and the solenoid is driven to open the switch to forcibly stop the power supply to the timer and to reclose the thermally responsive switch. Characteristic rice cooker.