JPH0489010A - Rice boiler - Google Patents

Abstract

PURPOSE:To obtain delicious rice by the synergism of lid heating and an effect of controlling the application of electric current to a heater for boiling rice by switching to the second set temperature higher than the first set temperature when a temperature sensor detects a temperature set higher than the first set temperature. CONSTITUTION:When it enters a boil-up process, electric current is fully applied to a rice boiling heater 2 by a current application control means 7. When the water temperature rises in a short time and the steam starts to be generated, the steam is applied to a lid 4, and the lid 4 is heated by the steam this time. A temperature sensor 6 provided on the lid 4 detects such a temperature rise, it is judged to be boiled when the sensor detects a temperature T (about 70 deg.C). When boiling is judged, the heating amount for the rice boiling heater 2 is decreased by the current application control means 7. Simultaneously, the set temperature of a temperature control means 8 is switched to the second set temperature (about 120 deg.C), so that the temperature of the lid 4 is controlled to the second set temperature from now and after. As the steam is generated before the interior of an inner pot 3 is completely boiled and the temperature T is set to a comparatively low temperature, about 70 deg.C, boiling can be detected a little before the interior is actually boiled and steam is generated hard.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a rice cooker that evenly heats rice by heating from the lid during cooking.

BACKGROUND OF THE INVENTION Conventional rice cookers have a technology that detects boiling by installing a temperature sensor on the lid to detect the temperature of the lid and utilizing the fact that the temperature of the lid rises due to boiling.

Based on the detection of boiling, the power supply to the rice cooking heater installed on the main unit is controlled, and the control is equivalent to the old saying, ``Start the rice slowly and slowly...'' 3 ( For example, JP-A-59-13
On the other hand, there is a technique in which a lid heater is provided on the lid and the rice is heated evenly and quickly by heating the rice from the lid as well. (For example, Japanese Utility Model Application Publication No. 62-100126) Problems to be Solved by the Invention Both of the above techniques are techniques for cooking rice deliciously, and if both are implemented simultaneously, very delicious rice can be obtained. However, if the lid is heated, the temperature of the temperature sensor provided on the lid will rise and boiling will be detected, so it has been impossible to do both at the same time.

Therefore, if the lid is equipped with only a temperature sensor, the temperature rise in the lid will be low and dew will easily form on the lid after boiling, while if the lid is equipped with only a lid heater, the temperature will rise quickly but the temperature will become too high. The drawback was that a lot of heat was dissipated from the lid.

Means for Solving the Problems The present invention has been made to solve the above problems, and includes a rice cooking heater and an energization control means for controlling the second energization in the main body of the rice cooker. A lid heater and a temperature sensor to detect the temperature are installed on the lid that closes the lid. Furthermore, the main body is provided with a temperature adjustment means for controlling the electricity supply to the lid heater so that the temperature detected by the temperature sensor becomes the set temperature.

The set temperature of the temperature control means is set to the first set temperature at the start of rice cooking, and when the temperature sensor reaches a temperature T (boiling detection temperature) set higher than the first set temperature, the set temperature is set to the first set temperature higher than the first set temperature. I switched to the second temperature setting.

Further, a timer was provided in the control section for controlling the temperature adjusting means, and the temperature was switched to the second set temperature after a certain period of time after the temperature T was reached.

Effects In the configuration of the present invention described above, the temperature control means energizes the lid heater based on the temperature detected by the temperature sensor from the start of cooking until the rice boils, and the temperature of the lid is controlled to be constant at the first set temperature. When it boils, the lid is heated by the steam, so the temperature of the lid rises above the first set temperature even though it is controlled at the first set temperature. When the temperature eventually rises to T, it is determined that boiling has occurred. When it is determined that boiling has occurred, the set temperature of the temperature adjustment means is switched to a second set temperature higher than the first set temperature and the temperature T. Thereafter, the temperature of the lid is adjusted to the second set temperature. At the same time, the heating amount of the rice cooking heater on the main body side is also controlled by the electricity supply control means.

With the above configuration, it is possible to perform heating from the lid using the lid heater, and at the same time, detect boiling and control the heating amount of the rice cooking heater. In this way, the lid heater can heat only at the first set temperature, which is relatively low, from the start of rice cooking to the detection of boiling, but since the water temperature is also low at the beginning of rice cooking, a sufficient heating effect can be obtained.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to the drawings. 1st
The figure is a sectional view of the rice cooker according to the present invention, FIG. 2 is a diagram showing the configuration of the heater circuit of the rice cooker, and FIG. 3 is an example showing the temperature characteristics of the lid and the current supply status to the lid heater. 1 in the figure is the main body,
2 is a rice cooking heater 3 is an inner pot, 4 is a lid, 5 is a lid heater, 6 is a temperature sensor, 7 is an energization control means, 8 is a temperature adjustment means, and 9 is a time measurement means.

Its structure is that a rice cooking heater 2 is attached to the inside of the main body 1, and an inner pot 3 is detachable (and stored in the main body 1).A lid 4 is attached to the main body 1, and a lid heater 5 and a A temperature sensor 6 is attached. Inside the main body l, an energization control means 7, a temperature adjustment means 8, and a clock means 9 which are controlled by a control section are provided, and the energization control means 7 includes a rice cooking heater 2. However, the lid heater 5 and the temperature sensor 6 are connected to the temperature adjustment means 8.

Next, the operation of this embodiment having the above configuration will be explained. A user puts rice and water in the inner pot 3, stores it in the main body 1, and closes the lid 4. Next, when the rice cooking switch (not shown) is pressed, the energization control means 7 starts energizing the rice cooking heater 2. At the same time, temperature adjustment is started by the action of the temperature adjustment means 8 so that the output temperature of the temperature sensor 6 becomes the first set temperature. That is, when the output temperature of the temperature sensor 6 is less than the first set temperature, the lid heater 5 is energized, and when it is higher than the first set temperature, the energization is stopped, thereby adjusting the temperature to the first set temperature. In this example, the first set temperature is set at 55°C.

The rice and water inside the inner pot 3 are heated from the top by the rice cooking heater 2, and at the same time they are also heated from above by the lid heater 5. The higher the water temperature, the more quickly rice absorbs water. If the rice heater 2 is used to heat only from the bottom, the temperature at the bottom will rise first, and only the rice at the bottom will absorb water. It becomes soft and the upper part becomes hard.

However, in this embodiment, since the lid heater 5 heats the rice from above as well, the temperature unevenness between the upper and lower parts can be reduced, and the rice can absorb water in the same way. In particular, in the microcomputer-controlled rice cookers that have become common in recent years, there is a step in the early stage of rice cooking, called ``preheating'' (referred to as immersion cooking J, etc.), in which the water temperature is kept constant for a certain period of time. If the water temperature of rice exceeds 60℃, the surface of the rice will start to gelatinize and will not absorb water to the core, so keep it at 40-50℃ for a certain period of time to allow the rice to absorb water to the core, and then cook it. There is. The configuration of this embodiment is particularly effective in allowing uniform heating in the second step.

When this process is completed and the rice cooking process begins, the electricity supply control means 7 fully energizes the rice cooking heater 2, and eventually the water temperature rises and when steam starts to come out, the steam hits the lid 4, which in turn heats the lid 4. . The temperature sensor 6 provided on the lid 4 detects this temperature rise, and the temperature T (approximately 70°
When C) is reached, boiling is determined. When the rice boils, the amount of heating by the rice cooking heater 2 is reduced by the energization control means 7. At the same time, the set temperature of the temperature adjustment means 8 changes to the second set temperature (approximately 1
20℃), and then the lid is switched to the second set temperature.
temperature is regulated. Steam is generated before the inside of the inner pot 3 completely boils, and the temperature T is set relatively low at approximately 70°C, so boiling is detected shortly before it actually boils and steam comes out violently. I can do it. Therefore, switching to the second set temperature from point 2 and holding the lid 4 at a high temperature has the effect of heating the rice. In addition, after violent boiling begins, it has the effect of preventing heat radiation from the lid 4, and the effect of preventing the above-mentioned dew condensation on the lid 4, and preventing dew from dripping onto the rice after the steaming process starts. As described above, in the present invention, the set temperature of the temperature control means for controlling the energization of the lid heater is set to the first set temperature lower than the boiling detection temperature (water temperature T) at the start of rice cooking. It is possible to detect boiling without heating, and when the temperature of the lid rises after boiling, the temperature is switched to the second set temperature which is higher than the first set temperature, thereby preventing heating and heat radiation. , the effect of preventing dew formation can be obtained, and the synergy of the effect of heating the lid and the effect of controlling the energization of the rice cooking heater by detecting boiling makes it possible to provide very delicious rice.

In this example, the power supply to the rice-cooking heater was controlled immediately after boiling was detected, and the set temperature of the temperature control means was switched. The operation of the energization control means may be delayed, or conversely, the switching of the set temperature of the temperature adjustment means may be delayed.

Alternatively, both the switching of the setting temperature of the energization control means and the temperature adjustment means may be delayed until the time measurement is completed.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a rice cooker according to an embodiment of the present invention, and FIG.
The figure shows the configuration of the heater circuit of the rice cooker, and Figure 3 shows the temperature characteristics of the lid and the current status of the lid heater. 1.Main body, 2.Rice cooking heater 4.Lid, 5..Lid heater 6..Temperature sensor, 7.Electrification control means, 8..Temperature adjustment means, 9..
Timekeeping means. Applicant Hitachi Hometech Co., Ltd. 7, Genden Bo/i Yanagi Handprint S, Temperature Control Means q Nail Fff Means Figure 2 Figure 3

Claims (2)

[Claims] (1), a rice cooker body (1) and a rice cooking heater (2),
An energization control means (7) for controlling this energization is provided, and a lid heater (4) is provided on the lid (4) that closes the upper opening of the main body (1).
5) and a temperature sensor (6) that detects the temperature, and further includes a temperature adjustment means (8) that controls the energization of the lid heater (5) so that the temperature detected by the temperature sensor (6) becomes the set temperature. The temperature adjusting means (8) is provided in the main body (1).
) is the first set temperature when rice cooking starts, and when the temperature sensor (6) reaches a temperature T higher than the first set temperature, the second set temperature is set higher than the first set temperature. A rice cooker characterized in that the rice cooker can be switched to. (2) The rice cooker according to claim 1, further comprising a timer (9) for measuring a certain time so as to switch to the second set temperature after a certain period of time after the temperature sensor (6) reaches the temperature T.