JPH0759226B2 - rice cooker - Google Patents

Description

TECHNICAL FIELD The present invention relates to a rice cooker capable of cooking rice and keeping heat.

2. Description of the Related Art Conventionally, this type of rice cooker has a structure as shown in FIG. 3, as disclosed in, for example, Japanese Patent Publication No. 63-60606.

That is, a lid 2 that is openably and closably provided on the main body 1, an inner pan 3 that is detachably accommodated in the main body 1, a rice cooking heater 4 that heats the bottom portion of the inner pan 3, and an inner side surface of the main body 1 are provided. A warmer heater 5 and a cover heater 6 provided on the lower surface of the cover 2 are provided. When heating rice, all the plurality of heating elements are energized, and when the heat is maintained, the warmer heater 5 and the cover heater 6 are energized to lower the inner pot 3. It was designed to keep a constant temperature with the pan sensor 7 provided in the.

However, with such a structure, the rice in the inner pot 3 has an optimum heat retention temperature of 73 ° C after switching to the heat retention mode at the end of rice cooking.
Until the temperature reaches, the lid heater 6 and the warming heater 5 are not energized, the temperature in the inner pot 3 is lowered, and when the pot sensor 7 reaches a predetermined temperature, it is energized and controlled to a constant temperature.
When the lid 2 is opened to remove the rice from the inner pot 3, the temperature of the lid 2 drops sharply, but since the rice remains inside the inner pot 3, the temperature is kept high. Next, when the lid 2 is closed, the temperature difference between the inner pot 3 and the lid 2 is large, so the steam generated from the rice adheres to the inside of the lid 2 and causes dew condensation, so that water drops drop on the rice. The taste of the rice that was kept warm by bleaching a part of the rice was deteriorated. Further, when the lid 2 is opened again, there is a problem that water droplets attached to the lid 2 may flow down.

Therefore, an object of the present invention is to provide a rice cooker that does not condense on the lid even when the lid is opened and closed while the temperature is kept warm, the taste is less deteriorated by the heat retention, and the dew does not flow out when the lid is opened.

Means for Solving the Problem And in order to achieve the above-mentioned object, the present invention, at the time of heat retention, energizes at least the heating means for heating and the heating means for lid to control the temperature by a pan sensor, and the temperature of the lid sensor is a pan sensor. The lid heating means is forcibly energized when the temperature falls below a predetermined temperature and reaches a predetermined temperature.

Effect The rice cooker of the present invention has the above-described structure, and at the time of keeping warm, at least the heating means for lid and the heating means for keeping warm are energized by the pan sensor to keep a constant optimum warming temperature, and when the outer lid is opened during warming. When the temperature of the outer lid falls and becomes lower than the temperature of the rice, the energization of only the heating means for the lid is started immediately to minimize the temperature difference with the rice and prevent dew condensation when the outer lid is closed. , Prevents the bleaching phenomenon that can be caused by the dew drop on warm rice. Also, when the outer lid is opened again, water droplets attached to the outer lid do not flow down.

Embodiment One embodiment of the present invention will be described below with reference to the accompanying drawings.

In FIG. 1, reference numeral 10 denotes a main body having an open upper surface, and a heat-retaining heater 12 and a body heater 13 as heat-retaining heating means are provided on the upper side surface of a protective frame 11 disposed inside the main body 10. A rice cooking heater 14, which is a heating means for rice cooking, is attached to the bottom. A pan sensor 15 is arranged at the center of the rice cooking heater 14 so as to come into contact with the bottom surface of a pan 16 which is detachably mounted inside the protection frame 11. Reference numeral 17 is an outer lid which covers the upper opening of the pot 16 and which can be freely opened and closed.On the underside of the pot 16 is provided a heat dissipation plate 18 made of a material having good thermal conductivity such as aluminum, and the outer lid is provided. A heat insulating material 19 is disposed between the upper side of 17 and the outside air side. A lid heater 20 as a lid heating means and a lid sensor 21 are attached to the heat dissipation plate 17.

As for the circuit configuration, as shown in FIG. 2, a heat retaining heater 12 and a switch element A23 are connected in series with a parallel circuit of a rice cooking heater 14 and a body heater 13 to a power source 22. Also, switch element B
24 is connected in parallel with the series circuit of the heat retention heater 12 and the switch element A23. Further, the lid heater 20 is connected to the power source 22 in series together with the switch element C25.

Next, the operation of the configuration of this embodiment will be described. At the time of rice cooking, the switch element 24 is first closed and the rice cooking heater 14 and the body heater 13 are energized to heat the rice and water in the pan 16 and start boiling. When boiled, steam rapidly raises the temperature of the lid sensor 21 to detect the set temperature, and the pot sensor 15
The amount of rice cooked in the pan 16 is accurately determined based on the difference between the time measured by and the boiling time, and the rice cooker 14
Will be input. At the same time, switch element C25 is closed,
The lid heater 20 is energized to heat the pot 16 from the entire surface. When the water content in the pan 16 decreases, the temperature of the pan bottom rapidly rises, the pan sensor 15 senses it, the switch element B24 is opened, and the heater is de-energized. When the Murashi process is completed,
The switch element C25 is opened, the lid heater 20 is de-energized, and the cooked rice is informed and cooking is completed. When the temperature of the rice gradually decreases and reaches the optimum heat retention temperature (73 ° C), the switch element A23 is closed and the heat retention heater 12, the body heater 13 and the rice cooking heater 14 are energized for a certain period with good balance, and then the switch element A23 is opened. , Switch element C25 is closed and lid heater 20
The product is energized for a predetermined time, and the whole heat retention heating is carried out in good balance. If the outer lid 17 is opened during this heat retention process, the temperature of the outer lid 17 will drop sharply and the lid sensor 21 attached to the heat sink 18
Senses the temperature and keeps the temperature of the pan sensor 15 set (72 ° C)
When the temperature is further lowered to 65 ° C, the switch element C25 is closed and the lid heater 20 is forcibly energized to maintain the temperature at a constant temperature near 65 ° C regardless of the determination of the pan sensor 15. Next, when this outer lid 17 is closed, the temperature of the rice and the heat sink 18 are sealed in a state where the temperature difference between them is small, so there is very little condensation, and the dew does not drip into the rice and the whitening phenomenon does not occur, keeping the delicious rice warm. it can. Further, even if the outer lid 17 is repeatedly opened and closed, dew does not flow down through the heat dissipation plate 18, so that there is no fear of soiling the body, desk, etc.

In the present embodiment, the lid heater temperature is set to 65 ° C. forcing the lid heater to be compulsory, but the lid heater temperature is not limited to this, and may be set to be slightly lower than the temperature of the pan bottom sensor at all times within a range not departing from the gist. It can be changed appropriately.

Although the heater is used as the heating means, the same effect can be obtained by using an induction heating coil, for example.

As described above, the present invention controls at least the heating means for heating and the heating means for lid at the time of heat retention by the pan sensor, and when the temperature of the lid sensor falls below the temperature of the pan sensor and reaches a predetermined temperature. Since a means for forcibly energizing the lid heating means is provided, it is possible to control the heating means for lids and the heating means for lids with a pan sensor during normal warming to keep the heat in a well-balanced manner. When the temperature of the outer lid decreases when the outer lid is opened, and the temperature of the pan sensor, that is, the temperature of the rice, drops, the heating means for the lid is forcibly energized to reduce the temperature difference between the outer lid and the pan and the rice. It can be made as small as possible, and it is possible to prevent dew condensation when the outer lid is closed, and it is possible to prevent rice from bleaching due to water drops falling on the rice while keeping it warm and to obtain rice with little deterioration. Further, even when the outer lid is opened and closed again, water droplets can be prevented from dripping and the container and the table can be prevented from becoming dirty.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a rice cooker showing an embodiment of the present invention, FIG. 2 is a circuit diagram of the rice cooker, and FIG. 3 is a partially cutaway front view of a conventional rice cooker. 12 …… Insulation heater, 14 …… Rice cooking heater, 15 …… Pan sensor, 16 …… Pan, 17 …… Outer lid, 20 …… Lid heater, 21 …… Lid sensor.

Claims (1)

[Claims] Claim: What is claimed is: 1. A pan for containing cooked rice, a heating means for cooking rice arranged at the bottom of the pan, a heating means for heating the body, and a heating means for the lid covering the upper opening of the pan. An outer lid provided, a lid sensor that senses the temperature of the pot side of the outer lid, a pot sensor that senses the temperature of the pot, and at the time of heat retention, at least the heating means for heating and the heating means for lid are energized, A rice cooker having a means for controlling the heat retention temperature by a pan sensor and forcibly energizing the lid heating means when the temperature of the lid sensor falls below the temperature of the pan sensor and reaches a predetermined temperature.