JPS6312816Y2 - - Google Patents

Description

[Detailed explanation of the idea] This invention relates to improvement of a rice cooker.

In order to cook rice deliciously, it is said that you need to keep the internal temperature of the pot at 98℃ or higher for about 20 minutes. However, in conventional rice cookers, the rice cooking heater is configured to generate heat at the rated output even when the water in the pot is low, so the rice cooking heater reaches the cooking temperature after the water in the pot is low. The time it takes for the rice to turn off is relatively short, and for this reason, conventional rice cookers have been unable to satisfy the above-mentioned conditions for deliciously cooking rice when the amount of rice to be cooked is small.

This invention was developed in view of the above circumstances, and its purpose is to always satisfy the condition for deliciously cooking rice, which is to maintain the internal temperature of the pot at 98°C or higher for about 20 minutes or more. It is possible to provide a rice cooker.

An embodiment of the present invention will be described below with reference to the drawings.

A timer device 1 used in a rice cooker according to the present invention is shown in FIGS. 1 to 3, and this will be described first. That is, 2 is a timer motor,
The rotational force of the rotary shaft 3 is transmitted to the timer shaft 4 via a reduction gear mechanism (not shown), and the timer shaft 4 rotates once every 21 minutes, for example, in response to energization of the timer motor 2. . 5 and 6 are cams connected to the time shaft 4, and 7 and 8 are cam switches opened and closed by the cams 5 and 6, respectively. In such a timer device 1, the time axis 4 is rotated once.
A timed operation is performed in which the cam switches 7 and 8 are closed as indicated by the hatched area in the time chart of FIG. 4 for 21 minutes. Specifically, during 21 minutes during one period of timed operation, the cam switch 7 closes the first 6-minute contact points f and d, and then closes the remaining 15 minutes.
Switching is performed so that the division point fe is closed,
In addition, the cam switch 8 repeats the operation of closing for 1 minute and then opening for 1 minute for the first 6 minutes (that is, while the contacts f and d of the cam switch 7 are closed), and is continuously closed for the remaining 15 minutes. will be accomplished.

On the other hand, in FIG. 5 showing the electric circuit configuration of the rice cooker, 9 is a temperature switch provided to detect the temperature of a pot (not shown) (hereinafter referred to as pot bottom temperature D), which responds to the rice cooking start operation. When the pot bottom temperature D reaches a predetermined cooking temperature, for example, 130 DEG C., contacts c and b are closed in response. In addition, 10 is a rice cooker heater for heating the pot, 11
is a normally open detection switch that detects the temperature of the pot.
This detection switch 11 is configured to be closed only when the bottom temperature D of the pot reaches, for example, 105°C, which is close to the finished cooking temperature (130°C). Reference numeral 12 denotes a power plug, between which the cam switch 8 and the rice cooker heater 10 are connected in series between the contacts c and a of the temperature switch 9, and the contacts of the cam switch 7 are connected in parallel to the series circuit of the cam switch 8 and the rice cooker heater 10. A series circuit of the detection switch 11 and the timer motor 2 is connected between f and d. Reference numeral 13 denotes a thermal reed switch of a well-known configuration for heat-retaining operation, and a series circuit between this and the heat-retaining heater 14 is connected between contacts c and a of the temperature switch 9 and the cam switch 8.
connected in parallel with the series circuit. Further, the rice cooking indicator lamp 15, the unevenness indicator lamp 16, and the heat retention indicator lamp 17 are connected together with resistors 18, 19, and 20, respectively, as shown.

Next, regarding the effect of the above configuration, the temperature characteristic curve of the bottom temperature D of the pot shown in FIG.
The explanation will be made with reference to the temperature characteristic curve of FIG. 8 and the time chart shown in FIG. In addition, in FIGS. 6 and 7, the pot bottom temperature D (°C) and the pot internal temperature E (°C) corresponding to the rice cooking time T shown on the horizontal axis are shown on the vertical axis, respectively, and in FIG. temperature switch 9,
Each closing period of the cam switches 7 and 8 and the energization period of the rice cooking heater 10 are indicated by diagonal lines. Therefore, the rice and water are stored in the pot, and the power plug 12
When the temperature switch 9 is set to close the contacts c and a with the cam switch 9 plugged into the power outlet, the cam switch 8 is closed at this point, so the temperature switch 9 contacts ( c.
-a) and the rice cooking heater 10 is energized via the cam switch 8, thereby heating the pot and starting the rice cooking operation. At the start of the rice cooking operation, the cam switch 7 is in a state where its contacts f and d are closed, but since the detection switch 11 is open, the timer motor 2 is not energized. After that, as the rice cooking continues, the water in the pot boils, and while the water in the pot remains in this state, the bottom temperature D of the pot is maintained at approximately 100°C, but the water in the pot does not melt into the rice. When it is absorbed and evaporated and the remaining amount decreases, the bottom temperature D of the pot gradually rises. Therefore, when the pot bottom temperature D reaches 105°C at time t ₁ , the detection switch 11 detects this and closes, and accordingly, the timer motor 2 is operated between contacts c and a, between contacts f and d, and The timer device 1 starts a timed operation by being energized via the detection switch 11. Then, for 6 minutes after the start of the timed operation, the cam switch 8 is alternately closed and opened every minute, so that the power to the rice cooking heater 10 is periodically interrupted and the output of the rice cooking heater 10 is reduced. As a result, the rate of increase in the bottom temperature D of the pan becomes slower. Then, at time _t2 , which is 6 minutes after the start of the timed operation of the timer device 1, the cam switch 7 switches the contacts fe to the closed state and the timer motor 2 is cut off, and the timer device 1
The timed operation is temporarily stopped, and the cam switch 8 is continuously closed, so that the rice cooking heater 10 is continuously energized. The water in the pot disappears due to the heating of the pot due to the electricity supply, and this causes a so-called dry-up state, and when the bottom temperature D of the pot exceeds 130°C at time _t3 , the temperature at which this is detected Switch 9 is contact c-b
It begins to close the gap. For this reason, rice cooking heater 1
0 is cut off and the rice cooking operation ends, and the timer motor 2 is energized across the contacts c and b, between the contacts fe and through the detection switch 11, and the timed operation of the timer device 1 is resumed. and then shifts to the irregular operation. At time _t4 , which is 15 minutes after the start of the irregular operation, the cam switch 7 switches the contacts f and d to the closed state, so the timer motor 2 is cut off and the timer device 1 is switched off.
When the timed operation of 21 minutes per cycle ends, the rice cooking operation is returned to the state before the start of the rice cooking operation, and accordingly, the uneven operation is ended and the warming operation is started. During this heat retention operation, the thermal reed switch 1 is activated when the internal temperature E of the pot drops below the predetermined heat retention temperature.
By the operation 3, the heat-retaining heater 14 is energized, and the temperature of the cooked rice, that is, the pot internal temperature E, is maintained at around the heat-retaining temperature. In addition, during the rice cooking operation, uneven operation, and warming operation as described above, the rice cooking indicator lamp 15 and the uneven rice cooking indicator lamp 16 are activated.
and the heat retention indicator lamp 17 are lit, respectively, so that each operating state is displayed.

According to the above-mentioned embodiment, when the pot bottom temperature D rises to nearly 130° C., which is the finished rice cooking temperature, the timer device 1 periodically turns on the rice cooking heater 10 to slow down the rate of rise in the pot bottom temperature D. As a result, the period during which the pot internal temperature E is maintained at 98℃ or higher becomes relatively long as shown in Figure 7. The above condition can be maintained for about 20 minutes). In addition, in this embodiment, the timer device 1 is configured to return to the initial state when one period of timed operation is completed, so that the above-mentioned conditions for deliciously cooking rice must be met every time rice is cooked. It is something that can satisfy you.

It should be noted that the present invention is not limited to the above-mentioned embodiments, and can be implemented with various modifications without departing from the gist thereof.

According to the present invention, as is clear from the above explanation, when the temperature of the pot heated by the rice cooking heater reaches the temperature at which the rice is cooked, the rice cooking heater is turned off and the rice cooking operation is terminated. This rice cooker is equipped with a temperature switch that can reliably satisfy the condition for deliciously cooking rice, which is to maintain the internal temperature of the pot at 98°C or higher for about 20 minutes or more.

[Brief explanation of drawings]

The drawings relate to one embodiment of the present invention.
2 and 2 are a side view and a front view of the timer device, respectively, FIG. 3 is a perspective view showing the main parts of the timer device in an exploded state, FIG. 4 is a time chart of the timer device, and FIG. 5 is an electrical diagram of the timer device. Circuit diagram, Figures 6 and 7
The figures are temperature characteristic curve diagrams for explaining the effects, and FIG. 8 is a time chart for explaining the effects. In the figure, 1 is a timer device, 9 is a temperature switch,
10 is a rice cooking heater, and 11 is a detection switch.

Claims (1)

[Scope of utility model registration request] A rice-cooking pot heated by a rice-cooking heater, and a temperature switch that turns off the rice-cooking heater and ends the rice-cooking operation when the temperature of the pot reaches the temperature at which the rice is cooked, wherein the temperature of the pot is a detection switch that is operated when the temperature rises close to the finished cooking temperature; and a timed operation for a predetermined time is started according to the operation of this detection switch, and during the timed operation period, electricity is periodically turned on to the rice cooking heater. A rice cooker characterized by being provided with a timer device that substantially reduces its output intermittently.