JPH0630842A - Rice boiler - Google Patents

Abstract

PURPOSE:To provide a rice boiler preventing such deterioration of food taste that the boiled rice under heat retention is locally dried and solidified or whitened and softened by dew condensation and capable of tastily retaining heat. CONSTITUTION:A rice boiler is provided with a container having a cover, a cover heater 14 heating the cover, temperature detecting means 15, 16 detecting the temperatures of the cover and the bottom of the container, and a control means 20 inputted with the signals of the temperature detecting means 15, 16 and controlling the cover heater 14, the heat retention process is started after the rice boiling process is completed, and the temperature of the cover heater 14 is controlled higher than the temperature of the bottom temperature detecting means 15 by the bottom temperature detecting means 15 and the cover temperature detecting means 16 until the preset heat retention temperature is reached, and the temperature difference is reduced with the passage of time. The temperature of the cover heater 14 can optimumly be controlled, and the whitening due to dew condensation on the cover or the yellowing due to drying can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rice cooker having a heat retaining function.

[0002]

2. Description of the Related Art Recent rice cookers having a heat-retaining function are naturally capable of cooking rice, and as a matter of course, there has been a demand for a heat-retaining function that can keep the food delicious.

A conventional rice cooker of this type is shown in FIGS.
Will be described with reference to. As shown in FIG. 3, a container 12 provided with a lid 11 at the top for containing rice and water, and this container 12
A protective frame 13 for supporting the lid 11, a lid heater 14 for heating the inside of the lid 11, a bottom temperature detecting means 15 for detecting the temperature of the bottom portion of the container 12, and a lid temperature detecting means 16 for detecting the temperature of the lid 11. The protective frame 13 has a bottom heater 17 for heating the bottom portion of the container 12, the upper portion of the protection frame 13 has a body heater 18 for heating the side surface portion of the container 12, a bottom temperature detecting means 15 and a lid temperature detecting means 16. Input the signal from the lid heater 14
And a control circuit board 19 for controlling the energization rates of the bottom heater 17 and the body heater 18.

Next, the operation of this rice cooker will be described. In the rice cooking process, the lid heater 14 is controlled by the signal from the lid temperature detecting means 16, and the bottom heater 17 and the body heater 18 are controlled by the control circuit board 19 by the signal from the bottom temperature detecting means 15, respectively. To do.

As shown in FIG. 4, after the rice cooking process is completed, in the heat retaining process, the bottom temperature detecting means 15 sets the prescribed heat retaining temperature T.
During the period until detecting w, the lid heater 14 is controlled at a constant energization rate, and after detecting the heat retention temperature Tw, the lid heater 14, the bottom heater 17, and the body heater 18 are all controlled by a signal from the bottom temperature detecting means 15. The control circuit board 19 controls the energization rate so that the temperature of the container 12 becomes the heat retention temperature Tw, and the heat is maintained.

[0006]

In such a conventional rice cooker, in the heat retaining step, the lid heater is controlled at a constant duty ratio until the bottom temperature detecting means detects the heat retaining temperature. When the room temperature was low, the dew condensation on the inside of the lid dropped onto the rice and turned white, and when the room temperature was high, the surface of the rice dried and turned yellow, which deteriorated the taste of the rice. .

The present invention solves the above problems,
The purpose is to keep warm so that the taste of rice does not deteriorate.

[0008]

In order to achieve the above object, the first means of the present invention is to provide a container having a lid on the top for containing rice and water, and a bottom heater for heating the bottom portion of the container. ,
A body heater that heats the side surface of the container, a lid heater that heats the inside of the lid of the container, a bottom temperature detection unit that detects the temperature of the bottom portion of the container, and a temperature of the lid portion of the container. And a control means for inputting signals from the bottom temperature detection means and the lid temperature detection means. The control means enters the heat retention step from the rice cooking step until a predetermined heat retention temperature is reached. During the period, the temperature of the lid heater is controlled by the bottom temperature detecting means and the lid temperature detecting means to be higher than the temperature obtained by the bottom temperature detecting means by a constant temperature.

The second means is to change the temperature of the lid heater to the bottom temperature detecting means by the bottom temperature detecting means and the lid temperature detecting means during the period from the rice cooking step to the heat retaining step until the temperature reaches a predetermined heat retaining temperature. The temperature is controlled to be higher than the temperature obtained by the above, and the difference between the temperature of the lid heater and the temperature due to the output of the bottom temperature detecting means is controlled to become smaller with the lapse of time.

[0010]

According to the present invention, with the above-described structure, the humidity in the container is high immediately after the rice cooking process is completed and the lid is closed during the period until the bottom temperature of the container reaches the specified heat retention temperature after the rice cooking process is transferred to the heat retaining process. Even when it is liable to form condensation or when the humidity is low and it is difficult to form
Since the temperature of the lid heater is constantly controlled to be higher than the temperature of the rice, the lid can be heated appropriately, and no condensation or drying occurs.
It is possible to prevent the surface of the rice from deteriorating in taste such as whitening due to dew drop or yellowing due to drying due to the ambient temperature.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.
Will be described with reference to.

The basic structure of the rice cooker of this embodiment is similar to that shown in FIG. That is, a container 12 having an upper lid 11 for containing rice and water, a protective frame 13 for supporting the container 12, a lid heater 14 for heating the inside of the lid 11, and a temperature of the bottom portion of the container 12 are detected. Bottom temperature detecting means 15
A lid temperature detecting means 16 for detecting the temperature of the lid 11, and a bottom heater 17 for heating the bottom portion of the container 12 in the protective frame 13.
Further, on the upper part of the protective frame 13, there is provided a body heater 18 for heating the side surface portion of the container 12. Further, as shown in FIG. 1, signals from the bottom temperature detecting means 15 and the lid temperature detecting means 16 are input to the lid heater 14, the bottom heater 17, and the body heater 1.
Control means 20 for controlling the duty ratio of No. 8 is provided. This control means 20 controls the heaters 14 and 1 from rice cooking to heat retention.
The energization control of each heater 14, 17, 18 is performed in accordance with the process storage means 22 that stores the energization rate of 7, 18, etc. Moreover, the temperature difference detecting means 21 detects the temperature difference between the bottom temperature and the lid temperature during the period from the completion of cooking rice until reaching the heat retention temperature, and the lid heater 14 of the lid heater 14 reduces the temperature difference with the lapse of time. Control energization.

Next, the operation of this rice cooker will be described. In the rice cooking process, the lid heater 14 receives signals from the lid temperature detecting means 16, and the bottom heater 17 and the body heater 18 receive signals from the bottom temperature detecting means 15, and the control means 20 controls the energization rate to perform rice cooking. .

As shown in FIG. 2, the lid heater 14 is obtained by the bottom temperature detecting means 15 during the period after the rice cooking step until the bottom temperature detecting means 15 detects the prescribed heat retaining temperature Tw in the heat retaining step. Controlled above the temperature.
At this time, immediately after the completion of the rice cooking process, when the humidity and temperature inside the container are high and dew condensation is likely to occur on the lid, the temperature difference between the lid heater 14 and the temperature obtained by the bottom temperature detection means 15 is large, and then the container is heated. It is programmed to reduce the temperature difference as the humidity and temperature inside the chamber decrease. Therefore, the temperature of the lid does not drop below the temperature of the rice, and no condensation occurs on the lid. Also, when the humidity and temperature in the container are low, the temperature difference between the lid and the rice is made small, so that the rice is not overheated and dried. After detecting the heat retention temperature Tw, the lid heater 14, the bottom heater 17, and the body heater 1
All of the control circuit boards 1 are controlled by the signal from the bottom temperature detecting means 15 so that the temperature of the container 12 becomes the heat retention temperature Tw.
The duty ratio is controlled by 9 to maintain heat.

In the present embodiment, the temperature difference between the lid heater and the bottom temperature detecting means is changed by a program, but it goes without saying that the same effect can be expected even if the temperature difference is constant.

[0016]

As is apparent from the above embodiments, according to the present invention, the lid heater temperature and the bottom temperature are high when the temperature of the container immediately after the heat retention step is high and a large amount of steam is generated and the humidity is high. Since the temperature difference between the temperatures due to the output of the detection means is increased and the temperature of the lid heater is controlled to be high, dew does not occur on the lid. In addition, as the temperature of the container decreases and the humidity decreases accordingly, it becomes difficult for dew condensation to occur, so the temperature difference is reduced and the amount of heating to the lid is not unnecessarily increased. Absent.
As a result, it is possible to provide a rice cooker that can keep warm deliciously without deteriorating the taste of rice such as whitening of rice due to dew attached to the lid and yellowing due to drying.

[Brief description of drawings]

FIG. 1 is a block diagram of a rice cooker according to an embodiment of the present invention.

FIG. 2 is a heat insulating process diagram of the rice cooker in one embodiment of the present invention

FIG. 3 is a side sectional view of a rice cooker according to an embodiment of the present invention and a conventional example.

FIG. 4 is a heat insulating process diagram of a rice cooker in a conventional example

[Explanation of symbols]

 11 Lid 12 Container 13 Protective Frame 14 Lid Heater 15 Bottom Temperature Detection Means 16 Lid Temperature Detection Means 17 Bottom Heater 18 Body Heater 20 Control Means

Claims (2)

[Claims] 1. A container provided with a lid on the top for containing rice and water, a bottom heater for heating a bottom portion of the container, a body heater for heating a side portion of the container, and an inside of the lid of the container. Lid heater, bottom temperature detection means for detecting the temperature of the bottom portion of the container, lid temperature detection means for detecting the temperature of the lid portion of the container, signals of the bottom temperature detection means and the lid temperature detection means And a control means for inputting the temperature of the lid heater by the bottom temperature detection means and the lid temperature detection means during the period from the rice cooking process to the heat retention process until the temperature reaches a predetermined heat retention temperature. A rice cooker that is controlled to have a constant temperature higher than the temperature obtained by the bottom temperature detecting means. 2. The control means enters the heat retention step from the rice cooking step,
The temperature of the lid heater is controlled by the bottom temperature detection means and the lid temperature detection means to be higher than the temperature obtained by the bottom temperature detection means during the period until reaching the predetermined heat retention temperature, and the lid heater The rice cooker is controlled so that the difference between the temperature and the temperature due to the output of the bottom temperature detecting means becomes small with the passage of time.