JPH08224167A - Jar-type rice cooker - Google Patents

Abstract

PURPOSE: To prevent a lid section from collecting condensation, and rice from getting dried and rotten, by giving fluctuation to temperature adjustment by disposing a apparatus temperature adjusting means, lid temperature adjusting means, and a changing means to change temperatures adjusted on the lid side at a constant cycle. CONSTITUTION: A control unit 11 is disposed with an apparatus temperature adjusting means 12 to adjust temperatures in an inner pot 6, a lid temperature adjusting means 13 to control a lid heating means 9 and adjust temperatures of a lid 7, and a changing means 14 to change the adjusted temperatures in the lid temperature adjusting means 13 at a constant cycle. The control unit 11 controls the inner pot 6 temperature at 74 deg.C and the lid 7 temperature at 73 deg.C, but under this condition, the lid 7 collects condensation because of its temperature being lower. At this time, the changing means 14 changes the adjusted temperature once every five minutes, for example, repeatedly. Specifically, the temperature adjusted by the lid temperature adjusting means 13 is changed from 72 deg.C to 78 deg.C to retain the lid 7 temperature at 79 deg.C for five minutes. Water condensed on the lid 7 moves into the inner pot 6. This process is repeated alternately. Thus, either of the lid 7 or the inner pot 6 can be kept free from condensation which occurs concentratedly in one of these two parts.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a jar rice cooker for improving the heat retention performance after cooking rice and providing delicious rice even if it is kept warm for a long time.

[0002]

2. Description of the Related Art A conventional jar rice cooker has an inner pot to be housed in the body and a lid for covering the body and the upper opening of the inner pot.
The main body is equipped with a main body heating means for heating the inner pot, a lid heating means for heating the lid to the lid, and a temperature adjusting means for the main body. The main body heating means and the lid heating means are energized by the temperature adjusting means to control the main body. And the rice is kept warm by keeping the lid at a substantially constant temperature. As an example of the temperature control method by the temperature control means, a pan bottom temperature sensor that is thermally coupled to the inner pan bottom part is provided at the bottom of the main body, and when the temperature of the pan bottom temperature sensor falls below a certain temperature, the main body heating means and the lid heating means are energized. Then, when the temperature of the pan bottom temperature sensor rises above a certain temperature, the energization is stopped to adjust the temperature so that the main body and the lid are kept at a predetermined substantially constant temperature. By keeping the main body and the lid at a substantially constant temperature, both the inner pot and the rice in the inner pot can be kept at an appropriate temperature (for example, Shoukai 62-10012).
No. 6 publication).

As a second example, in order to suppress temperature unevenness and dew condensation on the lid, a lid temperature sensor is newly provided on the lid, and the temperature of the main body heating means is controlled by the output of the pan bottom temperature sensor as in the first example. In some cases, the temperature of the lid heating means is adjusted independently by the output of the lid temperature sensor (see, for example, Japanese Utility Model Laid-Open No. 4-36922).

[0004]

In the first example in which the electric power control of the main body heating means and the lid heating means in the past is synchronized to adjust the temperature to a predetermined regulated temperature, or a lid sensor is newly provided in the lid part. In the second example in which the temperature of the lid heating means is controlled independently, the inner pot and the lid are configured to adjust the temperature to a predetermined substantially constant temperature. The inner pot is stabilized at a predetermined substantially constant temperature and the lid is maintained at a predetermined substantially constant temperature, and this stable state continues as long as the heat retention is continued.

However, it is very difficult to make the inner pot and the lid substantially constant temperature exactly the same temperature, and even if they are set to the same temperature, the heating amount (electric power) of the main body heating means and the lid heating means.
And temperature difference due to variations in the operating temperature of the pan bottom temperature sensor and the lid temperature sensor. In addition, there are differences in temperature between the inner pot and the lid. For example, the temperature of the inner pot near the main body heating means is high, and the farther away it is, the lower it is.

A problem here is that water is evaporated from the rice during the heat retention, and the evaporated water is condensed on a portion having a low temperature. When the temperature of the inner pot is lower than the temperature of the lid, moisture condenses on the inner pot, and the condensed water flows downward along the side wall of the inner pot and the rice in contact with the side wall of the inner pot gets wet and collapses like a paste. Occurs. Conversely, if the temperature of the lid is lower than that of the inner pot, dew will condense on the lid, the dew will drip from the lid onto the rice surface, and the rice surface will become paste-like, and when the lid is opened, a large amount of condensed water will flow to the main body side. There was a problem that it would get into the inner pot or flow over the top of the main unit to make it dirty.

[0007]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and includes an inner pot to be housed in a main body, a lid for covering the main body and an upper opening of the inner pot, and an inner pot. It has a main body heating means provided for heating the inner pan and a lid heating means provided for the lid to heat the lid, and a control section for controlling the power supply to the main body heating means and the lid heating means is provided to cook rice. Also, in a jar rice cooker that keeps rice at an appropriate temperature, the control unit controls the power supply to the main body heating means to control the inner pot on the main body side to a predetermined control temperature, and the power supply to the lid heating means. Then, a lid temperature adjusting means for adjusting the lid to another predetermined adjustment temperature and a changing means for changing the predetermined adjustment temperature on the lid side at a constant cycle are provided to give fluctuation to the predetermined adjustment temperature.

[0008]

According to the structure of the present invention, the predetermined adjusting temperature of the lid is changed to high or low at constant intervals by the changing means. Therefore, the temperature of the lid changes relative to the temperature of the inner pot adjusted to a substantially constant predetermined temperature, the temperature of the lid relatively increases or decreases, or the difference greatly increases or slightly increases. As a result, the dew condensation water of the one having a low temperature and dew condensation starts to evaporate, and the inside of the inner pot becomes high in humidity. Next, the moisture contained in the high-humidity air slowly begins to condense toward the newly lowered temperature. If the temperature rise / fall relationship is reversed at a constant cycle every time the dew condensation is completely changed to one side by the changing means, dew condensation will not be concentrated on either the inner pot or the lid. Condensation water does not drip into the inner pot, and a large amount of condensation water does not drip to the main body when the lid is opened. Furthermore, it becomes possible to keep condensation on the lid and to keep the rice dry and dry with minimal stickiness, and the evaporation of the condensed water keeps the inside of the inner pot at a high humidity to prevent the rice from drying.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view of a jar rice cooker according to an embodiment of the present invention, FIG. 2 is an operation flowchart during a heat retaining operation of the jar rice cooker, and FIG. 3 is an operation of the jar rice cooker and each part. FIG. 4 is a temperature characteristic diagram, and FIG. 4 is an operation flowchart during a heat retaining operation of a jar rice cooker to which another embodiment of the present invention is applied.

In the figure, an inner container 2 forming an inner wall of the container is attached inside a cylindrical main body 1 having an upper opening and a bottom. Main body heating means 3 composed of an electric heater is attached to the side surface of the inner container 2, and rice cooking heating means 4 composed of an electric heater or an induction heating coil and a pan bottom temperature sensor 5 are attached to the bottom of the inner container 2. The inner pot 6 is detachably accommodated in the inner container 2, and the bottom of the inner pot 6 and the pot bottom temperature sensor 5 are in contact with each other and thermally coupled.

A lid 7 is attached to the main body 1 via a hinge portion 8 so as to be openable and closable, and when the lid 7 is closed, the main body 1 is opened.
And the upper opening of the inner pot 6 is covered. A lid heating means 9 composed of an electric heater and a lid temperature sensor 10 are attached to a surface of the lid 7 facing the inner pot 6.

Inside the main body 1, there is provided a control section 11 to which the main body heating means 3, rice cooking heating means 4, pan bottom temperature sensor 5, lid heating means 9 and lid temperature sensor 10 are connected. Further, the control unit 11 receives the temperature of the pan bottom temperature sensor 5 and controls the energization of the main body heating means 3 and the cooked rice heating means 4 to adjust the temperature of the main body 1 side, that is, the inner pan 6 to adjust the main body temperature. A lid temperature adjusting means 13 for controlling the energization of the lid heating means 9 in response to the temperature of the lid temperature sensor 10 and adjusting the temperature of the lid side, and a change for changing the regulated temperature of the lid temperature adjusting means 13 at a constant cycle. It has means 14.

Next, the operation of this embodiment having the above configuration will be described.

The user puts the washed rice and an appropriate amount of water in the inner pot 6, stores it in the inner container 2 and closes the lid 7. Next, when a rice cooking operation is performed, rice cooking is started via the control unit 11, electricity is supplied to the rice cooking heating means 4, and the inner pot 6 is heated. Eventually, the inside of the inner pot 6 boils and the rice absorbs water, and when the water runs out, the temperature at the bottom of the inner pot 6 begins to rise sharply. When the pan bottom temperature sensor 5 catches the rapid rise in the pan bottom temperature, the control section 11 stops the energization of the cooked rice heating means 4 and finishes the heating. The control unit 11 continues to automatically shift to the purging operation, and after about 15 minutes, the cooked rice (including the Murashi) is finished and the cooked rice is cooked. The operation of the control unit 11 thereafter shifts to the heat retention operation.

Next, a description will be given of the operation after shifting to the heat retention operation with reference to FIGS. When the temperature of the pan bottom temperature sensor 5 falls below the control temperature T1 (for example, 72 ° C.) by the operation of the main body temperature adjusting means 12 of the control unit 11, the heat retaining operation energizes the main body heating means 3 to heat the inner pan 6 from the side. At the same time, a small amount of electricity is also applied to the rice cooking heating means 4 to heat the inner pan 6 from the bottom, and when the temperature of the pan bottom temperature sensor 5 becomes equal to or higher than the control temperature T1 due to heating, the main body heating means 3 and the rice cooking heating means 4 are heated. The operation of stopping energization is repeated. This keeps the inner pot 6 at a substantially constant temperature, for example, 74 ° C.

In parallel with the operation of the body temperature adjusting means 12, the operation of the lid temperature adjusting means 13 of the control section 11 causes
When the temperature of the lid temperature sensor 10 falls below the adjustment temperature FT1 (for example, 72 ° C.), the lid heating means 9 is energized to heat the lid 7, and when the temperature of the lid temperature sensor 10 becomes equal to or higher than the adjustment temperature FT1, The operation of stopping the power supply to the lid heating means 9 is repeated. This makes the lid 7
Is maintained at a substantially constant temperature, for example 73 ° C. When the temperature of the inner pot 6 is 74 ° C. and the temperature of the lid 7 is 73 ° C., the water evaporated from the rice is condensed on the lid 7 having a low temperature.

In this embodiment, the changing means 1 of the control unit 11
According to 4, the regulated temperature is repeatedly changed every fixed period, that is, every 5 minutes. As a result, the control temperature of the lid temperature control means 13 for 5 minutes is changed from FT1 (72 ° C.) to TF2 (78 ° C.) having a high temperature. This raises the temperature of the lid 7 and keeps it at, for example, 79 ° C. During this period, the temperature of the lid 7 becomes higher than the temperature of the inner pot 6 of 74 ° C., so that the water that has condensed on the lid 7 evaporates from the lid 7 to make the air in the inner pot 6 highly humid and the inner pot 6 Condensation begins to shift to the side.

After 5 minutes, the control temperature of the lid temperature control means 13 returns to FT1. As a result, the temperature of the lid 7 becomes lower than the temperature of the inner pot 6 again, and the condensed water on the side surface of the inner pot 6 becomes
Evaporates inside and starts to form condensation on the lid 7. As described above, during the heat retention operation, FT1 is alternately repeated for 5 minutes and FT2 is repeated for the next 5 minutes, and the operation of reversing the temperature relationship between the lid 7 and the inner pot 6 is repeated.

As described above, since the dew does not concentrate on either the lid 7 or the inner pot 6 and a large amount of dew water does not drip to break the rice, the rice can be kept warm in a delicious state. . Further, there is no problem that a large amount of condensed water flows when the lid 7 is opened. Furthermore, since the inside of the inner pot 6 is kept at a high humidity due to the evaporation of dew condensation water, it is possible to prevent the rice from drying and keep the rice warm in a delicious state with little drying even when it is kept warm for a long time.

Next, another embodiment of the present invention shown in FIG. 4 will be briefly described. Unlike the above-described embodiment, the lid temperature sensor 10 is not provided, and the temperature adjusting means of the control unit 11 operates only by the temperature of the pan bottom temperature sensor 5, and the main body heating means 3,
The temperature is adjusted by adjusting the electricity supplied to the rice cooking heating means 4 and the lid heating means 9.

For example, when the temperature of the pan bottom temperature sensor 5 becomes lower than the adjustment temperature T1 (for example, 72 ° C.), the main body heating means 3 is energized and the rice cooking heating means 4 is energized in a very small amount. At the same time, the lid heating means 9 is energized by controlling the energization amount to 70%. When the temperature of the pan bottom temperature sensor 5 becomes higher than T1, the power supply to each heating means is stopped. By repeating this, the inner pot 6 is kept at about 74 ° C, and the lid 7 is kept at about 72 ° C by repeating 70% energization and OFF.

Here, the electricity is supplied to the lid heating means 9 by 70% when the temperature of the pan bottom temperature sensor 5 is lower than the control temperature T1 by the changing means 14 of the control unit 11 at regular intervals.
To 100%. As a result, lid 7 is 100%
It is kept at about 78 ° C by repeating energization and OFF. As described above, even in the case where the temperature control by the temperature of the lid 7 is not performed, the temperature of the lid 7 is changed by changing the energization rate to the lid heating means 9 at a constant cycle, and the temperature of the inner pot 6 and the temperature Since the height relationship is reversed, the same effect as that of the one embodiment can be obtained.

[0023]

As described above, according to the present invention, in a jar rice cooker that cooks rice and then keeps the rice warm at an appropriate temperature, the controller controls the energization of the main body heating means to bring the inner pot on the main body to a predetermined adjustment temperature. A main body temperature adjusting means for adjusting, a lid temperature adjusting means for controlling energization to the lid heating means to adjust the lid to another predetermined adjusting temperature, and a changing means for changing the predetermined adjusting temperature on the lid side at a constant cycle, Since fluctuation is given to the lid's predetermined control temperature, it is possible to prevent dew condensation on the lid, rice drying due to the lid temperature rising too much, and rotting and stickiness due to the inner pot temperature falling too low.
It has the effect of providing a jar rice cooker that can keep warm for a long time.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a jar rice cooker showing an embodiment of the present invention.

FIG. 2 is an operation flowchart during a heat retention operation of the jar rice cooker.

FIG. 3 is a temperature characteristic diagram of the operation and each part of the rice cooker.

FIG. 4 is an operation flowchart during a heat retaining operation of a jar rice cooker according to another embodiment of the present invention.

[Explanation of symbols]

 1 Main Body 3 Main Body Heating Means 6 Inner Pan 7 Lid 9 Lid Heating Means 11 Controller 12 Main Body Temperature Adjusting Means 13 Lid Temperature Adjusting Means 14 Changing Means

Claims (1)

[Claims] 1. An inner pot to be housed in the main body, a lid for covering the upper opening of the main body and the inner pot, a main body heating means provided in the main body for heating the inner pot, and a lid provided in the lid for heating. In a jar rice cooker which has a lid heating means and which controls the main body heating means and the energization to the lid heating means, and cooks the rice and then keeps the rice at an appropriate temperature, the control part (11) has a main body. Main body temperature adjusting means (12) for controlling the energization to the heating means (3) to adjust the inner pot (6) on the main body (1) side to a predetermined adjustment temperature, and energization for the lid heating means (9). A lid temperature adjusting means (13) for adjusting the lid (7) to another predetermined adjustment temperature, and a changing means (14) for changing the predetermined adjustment temperature on the lid (7) side at a constant cycle. And a jar rice cooker.