JPS5844009A - Electric rice cooker - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is an electric rice cooker (including an electronic jar rice cooker) that is configured to automatically perform additional cooking and heating for a fixed interval after the rice reaches a predetermined temperature F after the end of cooking.

The same applies hereafter).

rt-r to cook rice deliciously, remove excess water that clings to the rice after cooking,
It is important to promote the gelatinization of starch in the rice grains even after the rice has been cooked, and to allow the gelatinization to proceed within the rice grains. The gelatinization of starch in rice grains has the property that when the temperature of the rice reaches a predetermined temperature Vcfx, the progress of gelatinization stops, or once stops, and the gelatinization process ceases to occur.

For this reason, in the past, a motor cam timer was used to perform additional cooking and heating at one batch time interval after the end of cooking (σ)t & after a predetermined period of time had elapsed, to remove the moisture that had stuck to the rice and to clean the inside of the rice cooker. If (maintain, starch α
The process was made to proceed in the core part of the rice grain, resulting in fluffy and delicious rice.

However, in the conventional electric rice cooker that performs additional heating using the motor cam timer, there is a difference in the rotational speed K of the motor because the power frequency is different between Kanto and Kansai.
There was a problem with the setting time changing. For this reason, there is peace of mind for vendors to indicate the timing and heating time of C-measuring heating for each of the Kanto and Kansai regions, while for those with low demand, it is important to note that if the frequency is different from that of a snowy region, , I took great care in cooking the rice with due care.

In addition, if the motor cam timer stops operating midway due to a power outage or unplugging the outlet plug, etc., if the motor cam timer is then turned on for warming, the motor cam timer VJ When the subsequent operations started I7, the timing VC was delayed (there was a problem when cooking and heating.

In addition, the conventional electric rice cooker #Ii, '(5) 11 of the rice cookers (≦ consists of members such as temperature-sensitive magnetic material, magnets, and springs in the lower position, and is movable to detect the end of rice cooking.

Equipped with a non-returnable temperature-sensitive rice cooking switch, it is designed to operate a lever operating part protruding from the window of the outer case of the rice cooker.
The movable non-recursive feeling LL rice cooking switch was mechanically operated to start rice cooking. Therefore, it is necessary to provide a space at the bottom of the rice cooker for arranging members such as a lever and a bearing member that transmits the f1 force applied to the lever operation part to the mechanical part of the rice cooking switch. I had no choice but to use an expensive electric rice cooker, which was one of the reasons for the cost increase.

The lever operating part had a design problem in that it had to be protruded from the lower part Km of the outer case of the rice cooker.

In view of the above-mentioned shortcomings of conventional electric rice cookers, this new rice cooker does not use a motor cam timer, but uses an automatic return type heat response switch and an OR circuit to perform additional heating, and only requires a manual operation switch. The purpose of the present invention is to provide a rice cooker that automatically starts cooking rice by energizing the rice cooker heater Kl by using mechanical members such as levers. It is.

The electric rice cooker according to the present invention (hereinafter referred to as the rice cooker of the present invention) will be described below with reference to drawings showing embodiments thereof.

The rice cooker lamp of the present invention is equipped with an electric circuit as shown in FIG. 1, and is a rice cooker heater for heating cooked rice. The rice cooking heater is shown in FIG. 2 and is embedded in the hot plate 2. In FIG.

is a break-type thermostat that opens when the rice is cooked, and an automatic return Mi-type heat-responsive switch.
As shown in the first factor, a heat transfer VC is installed on the bottom of the rice cooker heater l and the main switch SW to be described later!
A series circuit is formed with L, and the series circuit is connected to the AC power supply 6. In Figure 2, 8W.

outside case 8σ] Appropriate location K Ill/ ("I kera")
1. Hands that close only when operated! It is a %lJ switch with automatic return after operation, and as shown in FIG.

11, a discharge switch linked to the thermally responsive switch SW1 so as to close when the self-returning type thermally responsive switch SW1 is opened and open when the thermally responsive switch SWl is closed; The tTIU capacitor IO is connected in parallel to the tTIU capacitor IO via a resistor 17 to form a h1 discharge path. In the illustrated embodiment, the discharge switch 11 and the thermally responsive switch 8W1 are formed with switching contacts of one transfer type switch, and are interlocked with each other.

3 is a comparator, to which the voltage across the VCσ writing capacitor 100 is input, and to the negative input terminal K.
H constant voltage ■ is input. The voltage (1) is obtained by rectifying the voltage of the AC power supply 6 by the rectifying element 9, and then making it a constant voltage by the smoothing capacitor 5 and Zener diode 7. This is the voltage at point W. The output of the comparator 3 is input to the base of the transistor 14. The transistor 14
The collector is connected to one end of the AC power supply 6 via the relay RY and the rectifier 9, and the emitter is connected to the other end of the AC power supply 6. The main switch SW, a is a normally open contact that operates behind the relay RY. In the figure,
SW is an end switch for discharging the charge of the capacitor 10 connected in parallel with the capacitor IOK to stop rice cooking or cancel additional cooking;
As shown in the figure, it is provided below the manual operation automatic return lf6MJi switch svr. As shown in FIG. As shown in FIG. 3, the tool 16 has an open top box 163 placed inside an open top box 162 having a flange 61 at the top and biased upward against a spring 164. The upper opening box 163
As shown in the figure +7), there is a curve on the underside of the ceiling! , a thermally responsive switch SW□ is fixed in contact. Therefore, the ceiling of the upper closed box 163 is in direct contact with the bottom of the inner pot 4, and the heat-responsive switch 8W□ can detect the rice temperature extremely well.

In FIG. 1, 15 is a heater for keeping warm.

Next, the construction 111 of the rice cooker of the present invention will be explained.

When the manually operated automatic return type switch SW is suppressed, a voltage is applied from the AC power supply 6 to the capacitor lOK, and the h1 capacitor 1OVi is charged. In addition, FIG. 4(a) is a graph showing the time course of the voltage v2 across the iJ capacitor 10. As a result, the power supply voltage Vc is applied to the + side input terminal of comparator 3.
A voltage V' c c close to c K is input.

On the other hand, a constant voltage v1 is input to one side input terminal of the comparator 3, Vcr, j, and the constant voltage v1 is lower than the voltage V'cc as described below, so the comparison is not possible. A voltage close to the tJ power supply voltage Vcc is output from the device 3, and the transistor 14 becomes conductive. As a result, relay RY operates and l-1 main switch SW2 closes (see FIG. 4(b)). In addition, since the temperature is still low, the thermally responsive switches s W,+ are closed (see FIG. 4(C)), so the rice cooking heater 1 is energized, and rice cooking and heating begins. Figure 4 (, i) shows the heat Qσ generated by the rice cooking heater l.
) is a graph showing the passage of time. As the rice is heated, the value of the heat-responsive switch sW1 increases as shown in FIG. 4(θ)K. When the rice is cooked, the heat-responsive switches s w and h are opened [see Fig. 4 (c3)], and the rice cooking and heating are completed [see Fig. 4 (d)]. At the same time, the discharge switch 11 is closed, The charge stored in the capacitor IO begins to discharge through the resistor 17, and the voltage v2 across the capacitor 10 gradually begins to decrease as shown in FIG. , additional heating starts [Figure 4 (see al)]
. At the same time, the discharge switch 11 is opened, and the capacitor l (
The discharge 11 of No. 1 is stopped [see FIG. 4(a)]. When the temperature rises by 1° again, l') and thermal response switch 8W1
is opened [-1] The additional cooking heating by the rice cooking heater IK is completed [see Fig. 4 (0) and (d)].

At the same time, the discharge switch 11 is closed again, and the capacitor 10
is discharged, and the voltage v2 of the capacitor IO becomes as shown in Fig. 4(a).
As shown in K, it begins to decrease again. Then, when the voltage V of the capacitor lO drops to the low voltage V, VC,
Comparator 3 outputs only a low level voltage. As a result, the transistor 14 becomes non-conductive, the relay RY does not operate, and the main switch 5W2ij opens.
Figure 4(b) #Sho]. Therefore, even if the temperature T further decreases and the thermally responsive switch sW1 closes [see FIG. 4(e)],
The rice-cooking heater is not energized, no heating is performed, and the control level is lowered further, resulting in a heat-retaining state. In addition, F
The value of the voltage vl described in JII is set to match the value of the voltage v2 of the capacitor 10 after the time when the additional heating is completed and before the time when the thermal response switch BW□ is fully closed [Fig. (See X in alK) This is set in advance.

Furthermore, when the relay RY is operated by the voltage of the capacitor IO, an electric field transistor with high input impedance is used instead of the ordinary transistor 140, and the voltage of the capacitor IO is directly connected to the gate of the electric field transistor without going through the comparator 3. You can input it (not shown).

From the above, it is clear that the rice cooker of the present invention performs additional heating using an automatic post-clamping type heat-responsive switch and a CR circuit. There is no need to worry about the t1 additional heating time being different depending on the region.Therefore, the rice will not burn.Also, since it does not use a motor cam timer that requires a large space, The rice cooker is compact and has the advantage of being 111 (3R circuit is cheaper) in terms of cost.Furthermore, the rice cooker of the present invention has the following advantages:
Since no space is required to house mechanical members such as levers and bearing members, the electric rice cooker can be made low in volume, and from this point of view as well, significant cost reductions can be achieved.

Since it does not use mechanical parts such as levers and bearing members, it also has the advantage of not requiring the effort of assembling. Since the switch can be installed anywhere on the outside of the rice cooker, it also has the advantage of allowing the switch to be installed at the most desirable location in terms of design.
If you unplug it from the outlet, the automatic Kojikaku 1 type heat-responsive switch will close due to the drop in temperature.
When power is supplied again, additional heating is performed at rJ[f, and the advantage is that additional heating is not performed with a delay of VC, unlike the conventional motor cam timer.

[Brief explanation of the drawing]

The drawings are all for explaining the embodiments of the rice cooker of the present invention, and FIG. 1 is a wiring diagram of the electrical circuit of the rice cooker of the present invention, and FIG. 2 is a longitudinal sectional view of the rice cooker of the present invention. Fig. 3 is a cross-sectional view of the heat-responsive switch fitting of the rice cooker of the present invention, Fig. 4 is a graph showing the change in voltage v2 (vertical axis) of the rJ capacitor over time (horizontal axis), Fig. 4 (1: +) Graph showing the change in opening/closing of main switch 8W2 (vertical axis) over time (horizontal axis), Fig. 4(c) tlff thermal response switch sW engineering (
A graph showing changes in opening/closing over time (horizontal axis) (vertical axis), Figure 4 (
cl) tTf A graph showing the internalization of the heat Q (vertical axis) generated by the rice cooking heater over time (horizontal axis), Figure 4(e) H Heat response switch temperature T (vertical axis) over time (irl axis) )
It is a graph showing internalization. l... Rice cooking heater 9... Adjustable 151f element 10.
...Capacitor 11...Discharge switch 17...
Resistor SW, automatic rear type thermal response switch SW2...
・Main switch SW...Manual operation automatic reset type switch Patent applicant
Tiger Thermos Industry Co., Ltd. Representative Patent Attorney Toshihiko Uchida

Claims (1)

[Claims] l In an electric rice cooker that is equipped with a rice cooker and that automatically stops heating the rice once the rice is cooked and performs additional heating after a predetermined period of time, the rice cooker, the main switch, and the automatic A circuit consisting of a reset type thermally responsive switch is connected between the AC power supplies, and a capacitor is connected between the AC power supplies via a V flow element and a manually operated automatic reset switch. V(tJ, a discharge switch interlocked with the automatic reset type thermally responsive switch is connected in series through a resistor, and is controlled by adjusting the voltage of the capacitor No. 111 to the rillA-K switch.' Electric rice cooker.