JPH0436741Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Purpose of the Invention] (Field of Industrial Application) The present invention relates to a rice cooker that reduces the heating amount by approximately half when the boiled food reaches a boil during cooking.

(Prior art) Conventionally, in rice cookers, after the food (generally rice and water) has completely boiled during cooking, the amount of heating can be reduced by about half, that is, even if the input is about 50%, it will still reach 100%. It is already known that rice can be cooked under the same conditions as the input, and some practical versions of this have been provided solely for the purpose of improving economic efficiency. In this case, a thermal switch is installed at the bottom of the pot to detect the boiling of the food.

In the above case, the thermal switch cannot detect boiling at the bottom of the boiling food, but when the rice cooking capacity is large, the amount of boiling food in the pot is large and there is sufficient convection within the pot. Therefore, as shown in Figure 5, the upper part of the boiled food boils quickly and the lower part boils slowly, so that when the boiling of the lower part of the boiled food is detected, the upper part has already boiled, and therefore In a state where the entire food is brought to a boil, an operation can be performed in which the amount of heating is approximately halved by, for example, energizing the rice cooking heater every minute. However, in contrast,
When the rice cooking capacity is small, the amount of cooked food in the pot is small and sufficient convection does not occur within the pot, so as shown in Figure 6, the lower part of the boiled food boils faster and the upper part boils faster. Boiling is slow. For this reason, even when boiling is detected in the lower part of the boiled food, the upper part has not yet boiled, and therefore, the above-mentioned operation is performed to reduce the heating amount by approximately half while the boiled food has not completely boiled. This results in a drop in the temperature of the cooked food, as shown in A in Figure 6, which not only results in less delicious cooked rice, but also prolongs the cooking time, resulting in lower economic efficiency. It was not possible to achieve improvements in

On the other hand, some rice cookers equipped with a microcomputer are equipped with a program that quickly returns the power to 100% input when the temperature of the boiled food drops as mentioned above. Even this is not effective enough to compensate for the drop in temperature of boiled food, and the finished product is not very tasty.
Moreover, the cooking time was prolonged.

Therefore, it has been considered to change the time required to reduce the heating amount by half after the boiling of the cooked food for each model with a different capacity, as well as for the capacity of the rice actually cooked even if the model is the same. However, the control contents are complicated and the microcomputer cannot be shared, leading to an increase in cost. Furthermore, in this case, when the temperature correlation between the temperature at the bottom and the temperature at the top of the boiled food breaks down due to the amount of water or the mixing of ingredients for the cooked rice, the same result as described above will occur.
It was not an effective solution.

Another idea was to make the time from when the boiling of the cooked rice is detected until the amount of heating is reduced by approximately half. There is a problem in that rice cooking may be completed before starting the operation to reduce the heating amount by half, and the effect of controlling the amount of heating to be reduced by approximately half cannot be obtained at all.

(Problems to be Solved by the Invention) As described above, none of the conventional measures has been able to obtain the effect of controlling the amount of heating by approximately half without any problem.

Therefore, an object of the present invention is to provide a rice cooker which is excellent in practical use and can obtain the effect of controlling the amount of heating to be reduced by approximately half without causing any of the above-mentioned problems.

[Structure of the invention] (Means for solving the problems) The rice cooker of the invention includes a first heat-responsive body that operates by detecting boiling at the bottom of the boiled food, and and a second heat-responsive body that operates upon detecting boiling in the upper part of the rice cooker, and when both of the heat-responsive bodies operate to detect boiling during rice cooking, the amount of heating is reduced by approximately half.

(Function) According to the above means, the heating amount is controlled so that the heating amount is reduced by approximately half only when both the lower part and the upper part of the boiled food boil, that is, the entire boiled food boils.

(Embodiment) An embodiment of the present invention will be described below with reference to FIGS. 1 to 3.

First, in Figure 2, 1 is the container frame, and the outer frame 2
and an inner frame 3 and a heat insulating material 4 loaded between the two frames.
A rice cooking heater 5 is disposed at the bottom of the inner frame 3, and a pot 6 is disposed above it. Reference numeral 7 denotes a heat-retaining heater disposed around the upper outer periphery of the inner frame 3 so as to surround the pot 6. On the other hand, 8 is a well-known rice cooking switch mechanism that penetrates the bottom of the inner frame 3 and extends from the bottom of the pot 6 to the lower part thereof, and is placed in the outer bottom of the pot 6 in line with the heat-sensitive part 8a at its tip. A first thermally responsive body, for example a first thermal switch 9, is provided. On the other hand, 10 is a lid, which is also mainly composed of an outer lid 11 and an inner lid 12, both of which are provided with a steam vent tube 13 on one side. Reference numeral 14 denotes a detection tube provided on the other side of the lid 10, passing through the outer lid 11 and the inner lid 12 so that its tip faces the inside of the pot 6. A second thermally responsive body, for example a second A thermal switch 15 is provided. As a result, the first thermal switch 9 is activated by detecting the temperature of the lower part of the rice 16 and water 17, which are boiled food stored in the pot 6. , the second thermal switch 15 is adapted to operate by detecting the temperature of the rice 16 and water 17, that is, the upper part of the boiling food.
Both operate at boiling temperature, which is 100 [℃], and 60
It returns at a temperature below [°C], that is, considerably lower than the warming temperature, but since it does not directly detect the temperature of the boiled food, the activation and return temperatures must be set accordingly in anticipation of the difference. There is.

Next, in FIG. 1, reference numeral 18 denotes a plug that is plugged into a power outlet (not shown), and the rice cooking heater 5 is connected to this plug, and the temperature fuse 19 and the switch body 8 of the rice cooking switch mechanism 8 are connected to the plug.
Between the movable contact piece a and the fixed contact piece b of S and the relay 20
The movable contact piece a and the fixed contact piece b of the switch 20s are connected in sequence, and the rice cooker heater 5 is connected in parallel with the series connection circuit between the contact pieces a and b of the relay switch 20s. , the parallel connection circuit of the first thermal switch 9 and the second thermal switch 15 is connected via the coil 20c of the relay 20. A switch 21s is connected between the fixed contact piece c of the relay switch 20s and one end of the rice cooking heater 5, and is operated by the motor 21m of the timer 21 to repeatedly close and open the switch every minute, for example. Further, the motor 21m is connected between the fixed contact piece c of the relay switch 20s and the other end of the rice cooking heater 5. In addition, the switch body 8s in the rice cooking switch mechanism 8
The heat-retaining heater 7 is connected between the fixed contact piece c and one end of the rice-cooking heater 5 via a thermal switch 22 for heat-retaining.

Now, in the case of the structure as described above, when the operation to start rice cooking is performed, the switch main body 8s in the rice cooking switch mechanism 8 closes between the contact pieces a and b. The switch 9 and the second thermal switch 15 are both normally closed, as is clear from FIG. Since the space between b and b is closed and the rice cooking heater 5 is energized through the contact piece a and b, the rice cooking heater 5 generates heat and cooks rice at 100% input in this case. As a result, when the lower part of the cooked food (rice 16 and water 17) comes to a boil, the first thermal switch 9 detects this and opens, in this case opening, and when the upper part comes to a boil, The second thermal switch 15 detects this and operates. In this case, it also opens, so the coil 20c of the previous relay 20 is cut off and the switch 20s is brought into a state where the contacts a and c are closed. Therefore, when the motor 21m of the timer 21 is energized, the rice cooking heater 5 is energized via the switch 21s, which is repeatedly closed and opened every minute by the motor 21m. The rice cooking heater 5 starts to generate heat when the input power is about 50%, and the amount of heating for boiling food is approximately halved. At the end of rice cooking, the temperature of the pot 6 rises rapidly due to the loss of water in the cooked food, so the rice cooking switch mechanism 8 detects this with the heat sensitive part 8a and switches the switch body 8s to the contact plate a-. Then, the heat-retaining heater 7 and the rice-cooking heater 5 are intermittently energized in series via the heat-retaining thermal switch 22 to keep the cooked rice warm. While this heat retention is being performed, neither the first thermal switch 9 nor the second thermal switch 15 returns to normal, preventing the rice cooking heater 5 from generating heat with 100% input. Continue to do so.

In this way, according to this embodiment, the heating amount is controlled so that the heating amount is reduced by approximately half only when the lower part and the upper part of the boiled food are both boiled, that is, the entire boiled food is boiled. As a result, not only when the rice cooking capacity is large (see Figure 5), but also when it is small, the amount of heating can be reduced by approximately half without causing a drop in the temperature of the cooked rice, as shown in Figure 3. Because you can
Delicious cooked rice can be obtained, and the effect of improving economical efficiency can be surely obtained without prolonging the cooking time. Also, from this, it is possible to share the microcomputers without requiring models with different capacities or microcomputers with different programming in one model.
In addition, as mentioned above, even if you use a rice cooker that does not use a microcomputer, you can control the operation without any problems, so there will be no increase in costs. Even when the temperature correlation between the lower part and the upper part of the boiled food is disrupted due to the presence or absence of ingredients, the above-described operation control can be performed regardless of this. Furthermore, there is no need to make the time extremely long after detecting the boiling of the cooked food until the heating amount is reduced by approximately half.
Inconveniences such as completion of rice cooking with approximately half the heating amount when using a small capacity do not occur, and the effect of improving economic efficiency can be reliably obtained.

FIG. 4 shows a different embodiment of the present invention, in which a diode 23 is used in place of the above-mentioned timer 21 as a means of halving the amount of heating. 23 acts to flow only half-wave current in one direction to the rice-cooking heater 5, and has the effect of approximately halving the amount of heating, but is basically the same as described above, and therefore the same as described above. A similar effect can be obtained.

In addition, the amount of heat that decreases after the bottom and top of the boiled food boils does not have to be exactly half, that is, 50%.
For example, it may be 40% or 60%, as long as it is reduced by approximately half. Further, the first thermally responsive body and the second thermally responsive body are not limited to the aforementioned thermal switches 9 and 15, but may be a thermistor or the like, especially in the case of a rice cooker equipped with a microcomputer.

In addition, the present invention is not limited to the embodiments described above and shown in the drawings, but particularly with regard to the specific placement positions of the first thermally responsive body and the second thermally responsive body, etc. It may be implemented with appropriate changes within the scope of the gist.

[Effects of the invention] As is clear from the above description, according to the rice cooker of the invention, the economical effect of halving the amount of heating when the simmering food reaches a boil in the middle of cooking can be achieved by using a large rice cooking capacity. Needless to say, it can be obtained reliably without sacrificing the taste of the rice even if it is small, and it can be achieved at a low cost. The effect can be obtained regardless of the presence or absence of ingredients, etc., and there is no problem of completing rice cooking before the amount of heating is reduced by half when using a small capacity, and the effect of improving economic efficiency is definitely achieved. It has various excellent effects such as:

[Brief explanation of the drawing]

1 to 3 show an embodiment of the present invention,
FIG. 1 is an electric circuit diagram, FIG. 2 is a cutaway front view of the entire rice cooker, and FIG. 3 is a diagram showing temperature changes in each part of the boiled food and control mode of heating amount during small-capacity rice cooking. Further, Fig. 4 is a diagram corresponding to Fig. 1 showing a different embodiment of the present invention, and Figs. 5 and 6 are diagrams showing the boiling conditions during large-capacity rice cooking and small-capacity rice cooking in a conventional rice cooker. It is a figure showing the control aspect of the temperature change of each part of cooking, and the amount of heating. In the figure, 5 is a rice cooking heater, 6 is a pot, 9 is a first thermal switch (first thermally responsive body), 15 is a second thermal switch (second thermally responsive body), and 16 is a rice ( 17 is water (boiled food), 20 is a relay, 21 is a timer, and 23 is a diode.

Claims (1)

[Scope of utility model registration request] The first heat-responsive body is activated by detecting the boiling of the lower part of the boiled food, and the second heat-responsive body is activated by detecting the boiling of the upper part of the boiled food. A rice cooker characterized in that the amount of heating is approximately halved based on the boiling detection operation of a responsive body.