JPS6025963B2 - rice cooker - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rice cooker equipped with a forced unevenness function.

Conventional rice cookers automatically switch from the rice cooking circuit to the heat retention circuit when rice cooking is completed, and maintain the heat retention state for 10 to 2 flours to achieve uneven cooking.

For this reason, there was a drawback that excess steam left in the pot adhered to the inner surface of the lid, etc., and the water droplets were returned to the pot, giving excessive moisture to the cooked rice. In addition, a method has been proposed in which water droplets forming on the inner surface of the lid are prevented by heating with an insulating heater, but even with this method, the amount of heat generated is insufficient due to the insulating heater, and the effect is sufficiently satisfactory. was not obtainable. The present invention has been made in view of the above circumstances, and uses two thermostats and a timer to control the power supply to the rice-cooking heater, thereby causing forced unevenness to occur after a predetermined period of time has elapsed after the completion of rice cooking. The object of the present invention is to provide a rice cooker that can improve the taste of cooked rice by releasing excess steam in the pot.

An embodiment of the present invention will be described below with reference to FIGS. 1 to 4.

In the figure, reference numeral 1 denotes a cylindrical outer case with openings on the upper and lower surfaces. Inside this, an approximately bottomed cylindrical inner case 3 serving as a pot storage area is disposed via a heat insulating material 2. The upper end of the case is fixed by screws or the like to an annular fog ring 4 made of heat-resistant plastic, for example, which is attached to the inner periphery of the upper end of the outer case 1. Reference numeral 5 denotes a bottom plate having support legs 6, which is fixed to the lower end of the outer case 1 by iron.

Reference numeral 7 designates a pot having a flange 8 facing outward formed on the green part of the upper end, and is disposed within the inner case 3 by placing the flange 8 on the upper surface of the dew receiving ring 4.

The height and outer diameter of this pot are each set to be smaller than the inner case 3. Therefore, a space 9 that is substantially sealed by the inner case 3 is formed around the outer periphery of the pot 7, and this space is Continuously faces the outer bottom surface and outer surface of 7. Reference numeral 10 denotes a rice-cooking heater consisting of a sheathed heater bent in an S-shape, which is placed in a space 9 at a predetermined distance from the pot 7 and attached to the inner bottom of the inner case 3 via an insulator 11 as a support member. 12, and the terminal portions 13 provided at both ends are passed through the insulator 11 and the bottom of the inner case 3 and pulled out into a space 14 closed by the outer bottom surface of the inner case 3 and the bottom plate 5. ing.

Reference numeral 15 denotes an automatic return type thermostat disposed at the inner bottom of the inner case 3, and is supported by a compression spring 17 so as to be able to move up and down within a guide cylinder 16 which is formed into a substantially cylindrical bulge. , the upper surface is brought into pressure contact with the outer bottom surface of the pot 7.

18 is a safety switch, which is closed when the upper surface of the thermostat 15 is pressed against the outer bottom surface of the pot 7;
It opens and closes in conjunction with the vertical movement of the thermostat 15 so that it opens when the thermostat 15 is removed.

Reference numeral 19 denotes a heat shield plate, and a lower heat insulating material 20 is held on the upper surface of the heat shield plate.

Reference numeral 21 indicates a timer 22, and reference numeral 23 indicates a heat-retaining heater attached to the upper outer peripheral surface of the inner case 3.

Reference numeral 24 denotes a plastic outer lid rotatably supported at the upper end of the outer case 1 by a hinge member 25, and a handle portion 26 for carrying is integrally formed on the upper surface.

Reference numeral 27 denotes an inner cover made of plastic, which is fixed to the inner surface of the outer cover 24 with screws 29 via a heat insulating material 28 .

3. A holding member located on the opposite side of the hinge member 25 and fixed to the upper end of the outer case 1. When the outer cover 24 is closed, the outer cover 24 is engaged with a latch 31 provided on the handle 26. An engaging portion 32 integrally formed with the dew receiving ring 4 is held so as to maintain the dew receiving ring 4 in a closed state.

The engagement between the latch 31 and the engaging portion 32 can be released by a push spade 33. A heating plate 34 is fixed to the lower surface of the inner cover 27 with screws 35, and a heat-retaining heater 36 is disposed on the upper surface thereof.

Reference numeral 37 denotes a thermostat for detecting food temperature, which is sandwiched between the inner cover 27 and the heating plate 34 at a substantially central portion thereof, and is biased by a compression spring 38 so as to be able to move up and down.

Reference numeral 39 denotes an inner lid whose peripheral edge is fixed to the flange 8 of the pot 7, and when the outer lid 24 is closed, the heat transfer cover 40 of the thermostat 37 comes into pressure contact with the center of this inner lid.

Reference numeral 41 denotes a steam vent tube, which passes through the outer cover 24 and the inner cover 27 and exits to the outside. It is attached airtightly and removably through the cable.

Reference numeral 45 denotes a dew tray detachably attached to the hinge portion 25.

Next, the electric circuit of the rice cooker having the above configuration is connected as follows.

That is, in FIG. 5, 46 is a power plug, 47 is a thermal fuse, 48 is a timer motor of the timer 21,
49,50' at the first and second contacts of the timer 21,
The first contact 49 is closed when the timer 21 is set,
Even after the timer motor 48 has been operated for the set time, it remains closed unless operated externally, and the second contact 5
It is closed when the timer is set, and is automatically opened after the timer motor 48 has operated for the set time. Reference numerals 51 and 52 indicate a heat retention indicator lamp and its protective resistor, 53 and 54 indicate a rice cooking indicator lamp and its protective resistor, and 55 indicates a temperature-sensitive reed switch.

The rice cooking heater 10 and the thermostat 15 are connected in series, and are connected in parallel to the series circuit of the timer motor 48 and the thermostat 37, and the second contact 5 of the timer 21 is connected to the series circuit of the timer motor 48 and the thermostat 37.
0 are connected in series.

The heat-retaining heaters 23 and 36 are connected in two halves, and one of the heat-retaining heaters 23 and 36 is connected so that the temperature-sensitive reed switch 55 can control energization during the heat-retention. In the above, the thermostat 15 is normally open, and turns OFF when the temperature reaches the end of rice cooking (e.g., about 133 qo), and turns ON when the temperature drops to L (e.g., about 118 qo).
On the other hand, the operating temperature of the thermostat 37 is set so that it is turned on at a temperature T (for example, about 870 degrees).

Next, the operation of the device having the above configuration will be explained.

Rice and the necessary amount of water are put into the pot 7, stored in the inner case 3, and the outer lid 24 is closed. When the pot 7 is stored, the thermostat 15 is pressed by its outer bottom, and the safety switch 18 is activated.
is closed. Next, the timer knob 22 is operated to appropriately set the operating time of the timer 21. As a result, the first contact 49 and the second contact 50 of the timer 21 are closed, energization of the rice cooking heater 01 is started, and rice cooking is started. At this time, one of the heat-retaining heaters 23 and 36 is also energized, but since the temperature-sensitive reed switch 55 is in the OFF state, these heat-retaining heaters 23 and 36 constitute a Z series circuit, and the amount of heat generated is extremely small. At this time, the rice cooking indicator lamp 53
lights up to indicate the rice cooking status. When the rice cooking heater 0 generates heat, the air in the almost sealed space 9 is heated and convection occurs, and this heated air and the inner case 3
The pot 7 is heated from almost the entire surface by the radiant heat reflected from the inner surface of the pot 7, and rice is cooked.

However, when the temperature of the cooked rice in the pot 7 reaches the predetermined temperature,
When the temperature T is reached, this temperature is detected, the thermostat 37 is turned on, and the timer motor 48 is activated.

After a few minutes, when all of the water in the pot 7 is absorbed by the cooked rice or turned into steam, the temperature of the bottom of the pot 7 rises rapidly, causing the thermostat 15 to When the temperature, that is, the temperature T3, is detected, the rice cooker is opened and power to the rice cooking heater 10 is cut off. At this time, the timer motor 48 is still within the set time and keeps the second contact 50 closed.
3 After that, as time passes, the temperature of the pot 7 decreases to temperature T2, and the thermostat 15 turns ON again to start energizing the rice cooker heater 101, discharging the excess steam remaining in the pot 7 to the outside. The so-called forced murashu, in which people are forced to let go, is carried out.
After that, the timer motor 48 completes its operation and the second contact 50
Open and switch to Keep Warm mode. In this state, the temperature-sensitive reed switch 55 is in the ON state, so all the heat-retaining heaters 2
3 and 36 are energized, and the amount of heat generated is changed to an amount sufficient for keeping warm. What is shown in FIG. 6 is a graph representing the temperature characteristics from the start of rice cooking to the transition to the heat retention state. The dashed line in the figure varies depending on the amount of cooked rice.
5 shows that the OFF temperature changes. As explained above, the present invention is an automatic return type thermostat that detects the temperature at the completion of rice cooking, cuts off power to the rice-cooking heater, and then restarts power to the rice-cooking heater when the temperature drops to a predetermined temperature. Then, the thermostat for detecting rice overflow, which operates at a temperature lower than the operating temperature of this thermostat, and the thermostat for detecting rice temperature start timing before the rice reaches the cooking completion temperature, and the set time is reached. Equipped with a timer device that opens the rice-cooking heater circuit after the rice-cooking heater circuit has elapsed, it is possible to detect rice-cooking completion and control false heating with a single automatic return thermostat without using any other parts, thereby eliminating forced unevenness ( This has the practical effect of being able to provide a rice cooker with a function (fake heating) at a low cost.

[Brief explanation of the drawing]

The figure shows one embodiment of the rice cooker according to the present invention.
The figure is a cutaway perspective view showing the internal structure, FIG. 2 is a vertical sectional view also showing the internal structure, FIG. 3 is a plan view with the outer lid removed, and FIG. 4 is a partial sectional view of the outer lid. FIG. 5 is an electric circuit diagram, and FIG. 6 is a temperature characteristic diagram. In the figure, 7 is a pot, 10 is a rice cooking heater, 15 and 37 are thermostats, 21 is a timer, 48 is a timer motor,
49 and 50 are the first and second contacts of the timer. Figure 1 Figure 4 Figure 2 Figure 3 Figure 5 Figure 6

Claims (1)

[Claims] 1. A rice-cooking heater, an automatic reset type thermostat that detects the temperature when rice cooking is completed and cuts off the power to the rice-cooking heater, and then starts energizing the rice-cooking heater again when the temperature drops to a predetermined temperature; There is a thermostat for detecting rice temperature that operates at a temperature lower than the operating temperature of this thermostat, and in conjunction with the operation of this thermostat for detecting rice temperature, it starts timing before the rice reaches the cooking completion temperature and waits for a set time. and a timer device that opens the rice-cooking heater circuit after the lapse of time.