JPS60851B2 - electric rice cooker - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides an electric rice cooker (including an electronic jar rice cooker) having a function equivalent to the "place fire" function of rice cooking in a stove.

The same applies hereafter). Conventional electric rice cookers have the following drawbacks because the rice heater turns off when the rice boils, and after that the rice is simply steamed using residual heat.

In other words, at the point of boiling, the water sucked into the rice grains makes the grains themselves appear solid with no fluidity, but there is still excess water left in the pot, and this water is absorbed by the residual heat. Simply steaming the rice does not remove it completely, resulting in only sticky, raw-cooked rice. In addition, in the steaming process using residual heat, the rice temperature decreases relatively quickly and Q conversion of starch in the rice grains stops, so Q conversion does not progress to the core of the rice grains, resulting in delicious rice. There were disadvantages such as: (Note that once the Qization stops, the Qization does not proceed even if reheated).

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide an electric rice cooker that heats rice over a calender after boiling.

The present invention will be described below with reference to drawings showing embodiments thereof.

FIG. 1 shows a lower section of the electric rice cooker according to the present invention, and shows 1
2 is an outer pot; 2 is a disk-shaped hot plate fixed to the upper surface of the bottom wall la of the outer pot 1; 3 is a heater; a sheathed heater of about 600 W is cast into the hot plate 2 in an annular shape. 4. A non-returnable thermal switch (hereinafter referred to as a rice cooking switch) whose operating temperature T, is set to match the ambient temperature corresponding to the end temperature of rice cooking, and is set at the center of the heating plate 2. It is located and installed inside the through hole.

Reference numeral 41 indicates a contact point of the rice cooking switch 4, which is closed only when the operating pestle 42, which moves up and down, is in the raised position shown by the solid line.

5 is a capacitor switch, and 51 is a contact thereof, which is open when the operating punch 42 is in the raised position shown by the solid line.

That is, the rice cooking switch 4 and the capacitor switch 5 are in a relationship such that when one is closed, the other is opened. 6
is an inner pot detachably housed in the outer pot 1, and the approximately central portion 6b of the bottom wall 6a is the heat sensitive part 4 of the rice cooking switch 4.
3 and the lower surface of the bottom wall 6a other than the central portion 6b are in heat conductive contact with the upper surface of the hot plate 2, respectively.

Reference numeral 7 denotes a lever for setting the operating pestle 42 of the rice cooking switch 4 to the raised position, and is pivoted by a shaft 8. Its tip 7a is connected to the lower end of the operating lever 42 with a pin or the like, and its rear end 7b is Opening □ formed on the side wall of the rice cooker main body case 9
The oil that protrudes from the part 10 so that the lever 7 can be operated from the outside is a temperature-sensitive switch consisting of a thermal reed switch that is heat-conductively attached to the bottom surface of the hot plate 2, and the It closes when the temperature drops below T2, which is slightly lower than the operating temperature T of the rice cooking switch 4, and opens when the temperature drops below T3, which is even lower than that.

The temperature T2 is preferably set to a temperature that matches the temperature at the temperature-sensitive switch attachment site at least 2 to 3 minutes after the power supply to the main heater is stopped due to boiling of the cooked rice. Further, the temperature T3 may be higher than the atmospheric temperature at the start of rice cooking. Reference numeral 12 denotes a manually operated automatic return type calendar fire button attached to the side wall of the rice cooker main body case 9, and is used to charge a capacitor to be described later.

Reference numeral 13 denotes a rice cooking switch actuating section composed of a solenoid 13a and an iron core 13b, which is held by a holder (not shown) screwed onto the top surface of the bottom wall of the rice cooker main body case 9, and which controls the tip end 7a of the lever 7. The rice cooking switch 4 is closed by pushing up the iron core 13b.

FIG. 2 shows an electric circuit of an electric rice cooker according to the present invention.
The heater 3 and the contact 41 of the rice cooking switch 4 are connected in series, and the series circuit is connected to the ACIOOV power source.

14 is the capacitor 15, contact 5 of the capacitor switch 5
1. Counterfeit button 12 "It is a charging circuit in which a diode 19 is connected in series, and is connected to the ACIOOV power supply.

Reference numeral 12 denotes a manually operated automatic return type layered fire button, which is closed only when pressed to start rice cooking for the first time, and is in the open state at other times.

Also, break type thermal reed switch 1 with operating temperature T2.
1a, a series circuit of the make-type thermal reed switch 11b with an operating temperature of T2 is connected in series with a temperature-sensitive switch 11 and a resistor 16. The discharge circuit 17 is connected in parallel to the circuit. Reference numeral 18 denotes a discharge detection circuit for detecting the occurrence of discharge in the discharge circuit, which is composed of a transistor 18a, whose emitter terminal is connected to one of the power supply terminals c, and whose collector terminal is connected to the solenoid 1.
It is connected to the connection point A between the calendar fire button 12 and the diode 19 via the terminal 3a, and its base terminal is connected to the connection point B between the resistor 16 and the temperature-sensitive switch 11.

The electric rice cooker of the present invention constructed as described above operates as explained in detail below. FIG. 3a shows the circuit state when the false fire button 12 is closed in order to charge the capacitor 5 before pushing down the rear end 7b of the lever 7 to start cooking rice.

Since the contact 41 of the rice cooking switch 4 is not yet closed, the contact 51 of the capacitor switch 5, which operates in the opposite direction, is closed, and the diode 19, the hawk fire button 12, the contact 51 of the capacitor switch 5, and the capacitor A voltage is applied to a charging circuit 14 consisting of a series circuit, and the capacitor 5 is charged. At this time, the ambient temperature of the temperature sensitive switch 11 is lower than T3, so the make type thermal reed switch 1ib is opened, and no voltage is applied to the base emitter of the transistor 18a, so no collector current flows. Therefore, no current flows through the solenoid 13a and the iron core 1
3b doesn't move. Next, by pushing down the rear end 7b of the lever 7, the rice cooking switch 4 is closed, the contact 51 of the capacitor switch 5 is opened (the state shown by the solid line in FIG. (See Figure 3 b). As a result, the ambient temperature rises and the make-type thermal reed switch 11
When the operating temperature T3 of b is reached, the thermal reed switch 1
1b is closed as shown in FIG. 3c, and at this time the operating temperature T
2 (>T3) break type thermal reed switch 11
a is also closed, but the contact 51 of the capacitor switch 5
Since the capacitor 15 is open, no discharge occurs in the capacitor 15.
When the temperature rises, the break type thermal reed switch 11a
When the operating temperature T2 is reached, the switch 11a opens,
When the temperature further rises and reaches the operating temperature T of the rice cooking switch 4, the contact 41 of the rice cooking switch 4 opens and the contact 51 of the capacitor switch 5 closes (as shown by the two-dot chain line in Fig. 1). situation). However, since the break type thermal reed switch 11a is already open at this time as described above, no discharge occurs (see FIG. 3d). When the non-heating state continues for a while due to the opening and closing of the rice cooking switch 4, the temperature decreases and reaches the operating temperature T2 of the break type thermal reed switch 11a. At this time, since the switch 11a is opened, the discharge circuit 17 is also closed, and therefore the capacitor 5 is discharged. As a result, a voltage is applied between the base and emitter of the transistor 18a by the resistor 16, and a collector current flows to the solenoid 13a (see FIG. 3e). Since it is pushed up by the iron core 13b, the contact 41 of the rice cooking switch is closed (see FIG. 3f). As a result, heating by the heater 3 is started again. This is heating over a standing fire. When the temperature rises to T, the contact 41 of the rice cooking switch 4 is opened and closed again, so that the heating over the stove is completed and the contact 51 of the capacitor switch 5 is closed. When the temperature drops to L due to the end of heating, the break type thermal reed switch 11a closes, but since the capacitor 15 is not charged, no discharge occurs and the solenoid 13 is closed again.
The rice cooking switch 4 is not closed due to the action of a.
Therefore, false heating will not be started again. It goes without saying that the discharge detection circuit 18 may be a thyristor or the like. Further, the temperature-sensitive switch 11 may be composed of a bimetal 20, an electrode 21, an insulator 22, etc. as shown in FIG. 4, instead of being composed of the thermal reed switches 11a and 11b as described above. i.e. bimetal 2
When the ambient temperature at 0 rises, the bimetal 201 bends in the direction of the arrow, contacts the electrode 21 at the temperature T3 mentioned above (the state shown by the two-dot chain line 20a), and further separates from the electrode 21 at a temperature T2 or higher (2 (state shown in dashed dotted line 20b). Therefore, the temperature-sensitive switch using this bimetal 20 has the characteristic of opening at temperatures below T3, closing between temperatures T3 and L, and opening at temperatures above T2. As mentioned above, the electric rice cooker according to the present invention performs pupil heating in a timely manner after heating the rice and completely drains excess water, so there is no chance of the rice being cooked raw, and the rice is quickly salted. Since the quality of the starch in the rice grains does not decrease, the Q conversion of starch in the rice grains can be sufficiently promoted, resulting in delicious rice.

Furthermore, a non-heating state is provided for a certain period of time immediately after the rice is heated.
Since the extra water interposed between the rice grains is condensed and then heated in a subsequent layer, the above-mentioned pupil fire effect can be made even greater.

[Brief explanation of the drawing]

Fig. 1 is a schematic lower longitudinal sectional view of the electric rice cooker according to the present invention, Fig. 2 is an electric circuit diagram of the electric rice cooker, and Fig. 3a shows the state when the capacitor is charged by pressing the pupil button. b is when the rice cooking switch is closed, Fig. 3c is when the temperature rises and the temperature sensitive switch is closed, Fig. 3d is when the rice has boiled and the rice cooking switch is opened, Fig. 3e is When the temperature drops and the temperature-sensitive switch closes and discharge occurs, Figure 3 f shows the circuit states when the rice-cooking switch opens due to electromagnetic force, and Figure 4 shows the circuit state when the rice-cooking switch opens due to electromagnetic force. Figure 4 shows the temperature-sensitive switch using bimetal. It is a figure showing a switch. 3. ．． ．． ．． ．． ．． Heater, 4...Rice cooking switch,
41... Rice cooking switch contact, 5... Capacitor switch, 51... Capacitor switch contact,
11...Temperature sensitive switch, 11a...Break type thermal reed switch, 11b...Make type thermal reed switch, 12...Layer fire button, 1
3...Rice cooking switch operating section, 13a...Solenoid, 13b...Iron core, 14...Charging circuit, 15...Capacitor, 16... Resistor, 17...Discharge circuit, 18...Discharge detection circuit, 18a...Transistor, 19...Diode, 20...Noguimetal, 21""" electrode, 2
2...Insulator. Figure 1 Figure 2 Figure 4 Figure 3

Claims (1)

[Claims] 1. In an electric rice cooker equipped with a rice cooking circuit in which a heater and a thermal rice cooking switch that controls energization to the heater are connected in series, the charging circuit in which a capacitor, a capacitor switch, a fire button, etc. are connected in series is connected to the rice cooking circuit. A discharge detection circuit is connected to a power supply in parallel with the circuit, and a temperature-sensitive switch and a resistor connected in series are connected in parallel to the capacitor and the capacitor switch to form a discharge circuit, and detect discharge in the discharge circuit. is connected in relation to the discharge circuit, and is provided with a rice cooker switch actuator that causes the rice cooker switch to perform a heating operation based on the output from the discharge detection circuit, and the rice cooker switch and the capacitor switch are capable of opening and closing operations. The electric rice cooker is characterized in that the temperature-sensitive switch is connected in a reverse manner, and the temperature-sensitive switch is set to close the discharge circuit at a temperature slightly lower than the boiling opening operation temperature of the rice cooking switch. .