JPH0838347A - Rice cooker - Google Patents

Abstract

PURPOSE:To provide a rice cooker for uniformly heating an inner pan with inexpensive structure. CONSTITUTION:A heating element 6 with a built-in electrothermal heater 5 is provided at an inner bottom part 2B of an outer pan 2. On the other hand, a flange-shaped projecting part 4E is formed on the outer surface of the side part 4C of an inner pan 4. When the inner pan 4 is housed in the outer pan 2, a heating space 9 is formed under the projecting part 4E. Thus, just by forming the projecting part 4E on the outer surface of the side part 4C of the inner pan 4, uniform heating is enabled just as covering the lower part of the inner pan 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rice cooker such as an electric cooker, and more particularly to a rice cooker for heating cooked food contained in an inner cooker at a high temperature.

[0002]

2. Description of the Related Art Generally, a rice cooker of this type stores rice to be cooked and water in an inner pot, and after closing the upper opening of the inner pot with an inner lid, heating means such as an electric heater is used. This heats the inner pot to perform a series of heating operations from water absorption of rice to heat retention of rice. In this case, in order to cook the rice deliciously and fluffy, it is necessary to wrap the inner pot and perform high-temperature and uniform heating. Conventionally, the wall thickness of the entire inner pot has been increased, or pressure has been increased. There has been known a method of electromagnetically heating the inner pot itself by a pot or an induction heating system (IH system).

[0003]

SUMMARY OF THE INVENTION In the above-mentioned prior art method, the wall thickness of the entire inner pot is increased in order to obtain high temperature and uniform heating, or in the case of a pressure cooker, a dedicated pressure vessel or pressure relief valve is used. A complicated structure such as is required, which causes a cost increase. Further, when the induction heating method is adopted, it is necessary to separately form a heating layer made of a magnetic material in the inner pot, facing the coil that generates a high frequency current, and there is a concern that the cost will be further increased. .

The present invention is intended to solve the above problems, and an object of the present invention is to provide a rice cooker capable of uniformly heating the inner pot at a high temperature with an inexpensive structure.

[0005]

According to the present invention, there is provided an inner pot for accommodating cooked food, an outer pot for accommodating the inner pot so that the inner pot can be inserted and removed, and an inner pot provided at an inner bottom portion of the outer pot. In a rice cooker having heating means for heating, a protrusion is formed over the entire circumference in a substantially intermediate portion between an upper end and a lower end of a side outer surface of the inner pot, and is located below the protrusion of the inner pot. A heating space is formed between the outer pot and the inner pot.

[0006]

With the above-mentioned structure, only by forming the protrusion over the entire circumference of the outer surface of the side portion of the inner pot to form the heating space, the radiant heat emitted to the heating space below the protrusion causes the lower portion of the inner pot. The high temperature and uniform heating is performed so as to wrap around.

[0007]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows a first embodiment of the present invention,
In the figure, reference numeral 1 denotes a bowl of a rice cooker, which is composed of an outer pot 2 made of, for example, aluminum having high thermal conductivity, and a case 3 made of synthetic resin or the like. Reference numeral 4 denotes a bottomed cylindrical inner pot for containing rice to be cooked and water, which is housed in the outer pot 2 in a removable state. The inner pot 4 is formed in a flat bottom portion 4A formed substantially in the center, an inclined portion 4B formed on the outer periphery of the bottom portion 4A, and an outer periphery of the inclined portion 4B in an upright state than the inclined portion 4B. And an opening end portion 4D that is an upper end of an outer surface of the side portion 4C of the inner pot 4.
It should be noted that the flange-shaped protrusion 4E is formed thicker than the other portions in the substantially middle portion of the bottom portion 4A which is the lower end over the entire circumference.

On the other hand, the outer pot 2 has a bottomed tubular shape as a whole, and is composed of a side portion 2A formed in a substantially upright state and an inner bottom portion 2B having a smaller diameter than the side portion 2A. A heating element 6 having an annular electric heater 5 as a heating means is provided above the inner bottom portion 2B. Further, a temperature sensor 7 for detecting the temperature of the inner pot 4 is provided by penetrating substantially the center of the heating body 6, and this temperature sensor 7 is provided by the elasticity of the spring 8 when the inner pot 4 is housed. It comes into contact with the outer surface of the bottom portion 4A. The upper surface of the heating body 6 is formed into a substantially concave spherical shape, and when the inner pot 4 is housed in the outer pot 2, the upper surface of the heating body 6 is covered with a part of the bottom portion 4A of the inner pot 4 and the outer surfaces of the inclined portions 4B. And a heating space 9 heated by the heating body 6 together with the inner pot 4 is formed between the inner pot 4 and the outer pot 2 below the protrusion 4E.

Reference numeral 11 denotes a pair of connection terminals which are provided so as to penetrate the outer pot 2 from below one side of the heating body 6.
Thus, electrical connection with the outside is achieved. Reference numeral 12 denotes an operation display unit having a timer switch 13 and the like, which is provided on one side of the case 3. Reference numeral 14 denotes an openable / closable lid that covers the upper opening of the vessel frame 1. This is an open end 4D of the inner pot 4 via an outer lid 15 made of synthetic resin and an elastic member 16.
And an inner lid 17 that is pressed against. The inner lid 17 has an opening 17
A is provided and communicates with this opening 17A,
The outer lid 15 is provided with a steam hole 18 for discharging the steam in the inner pot 4 to the outside. In addition, 19 is a handle provided in the upper center of the outer lid 15, and 20 is an outer peripheral recessed portion 17B of the inner lid 17 and an open end portion 4D of the inner pot 4.
It is a packing interposed between and.

In the rice cooker having the above-mentioned structure, the temperature sensor 7 detects the temperature of the inner pot 4, and the electric heater 5 is turned on and off to perform a predetermined rice cooking and heat-retaining operation from water absorption of rice to heat retention of rice. I do. When the electric heater 5 is energized, the heating body 6 surrounding the electric heater 5 is heated by the heat emitted from the electric heater 5. Therefore, the inner kettle 4 in contact with the heating body 6 is not limited to the bottom portion 4A and the inclined portion 4B around the heating body 6 due to its good thermal conductivity, but also to the portion above the side portion 4C apart from the heating body 6. Is quickly heated to. On the other hand, radiant heat is radiated from the side portion and the bottom portion of the heating body 6 which are not in contact with the inner pot 4 toward the heating space 9 formed between the inner pot 4 and the outer pot 2. Since the protrusion 4E formed over the entire circumference of the inner pot 4 receives it substantially uniformly, the lower portion of the inner pot 4 located below the protrusion 4E is further heated by the radiant heat from the heating body 6. Therefore, irrespective of the amount of cooked rice, the lower part of the inner pot 4 in which the rice to be cooked is housed is always wrapped, and the radiant heat from the heating body 6 is used for uniform heating. Further, even after cooking rice, the radiant heat accumulated in the protrusion 4E and the heating space 9 can keep the high temperature so as to wrap the lower portion of the inner pot 4, so that delicious plump rice can be eaten.

The rice cooker of the present embodiment does not have to be thicker as a whole, or a pressure cooker having a complicated structure or an induction heating type rice cooker is adopted unlike the conventional case. By merely forming a thick annular protrusion 4E on the outer surface of the side portion 4C constituting the inner pot 4, the inner pot 4 is heated by the radiant heat emitted to the heating space 9 below the protrusion 4E. It is possible to perform high temperature and uniform heating by enclosing the lower part of the. That is, according to claim 1, an inner pot 4 for containing the rice to be cooked, an outer pot 2 for housing the inner pot 4 provided while forming a heating space 9 with the inner pot 4, and a heating space 9. And an electric heater 5 for heating the inner pot 4, and by forming a flange-shaped (collar-shaped) protrusion 4E on the outer surface of the side portion 4C of the inner pot 4 over the entire circumference, an inexpensive structure can be obtained. It is possible to heat the kettle 4 uniformly at high temperature.

Next, a second embodiment of the present invention will be described with reference to FIGS.
It will be described based on. The same parts as those in the first embodiment are designated by the same reference numerals, and detailed description of the common parts will be omitted. In FIG. 2 showing a cross-sectional view of the rice cooker, an outer pot 2
A step portion 2C is formed over the entire circumference on the side portion 2A, and a concave portion 2D formed in the center of the inner bottom portion 2B is
A temperature sensor 7 having a spring 8 is provided. A mounting table 21 is provided on the inner bottom portion 2B of the outer pot 2, and an electric heater 5 is disposed above the mounting table 21 in an exposed state with respect to the heating space 9. When the inner hook 4 is housed in the outer hook 2, the protrusion 4E of the inner hook 4 contacts the step 2C of the outer hook 2, and the inner hook 4 is supported in a suspended state. The other points are the same as those of the rice cooker in the first embodiment.
In the present embodiment, the radiant heat emitted from the electric heater 5 to the heating space 9 quickly heats the inner pot 4 having a high thermal conductivity, but the radiant heat is received by the protrusion 4E of the inner pot 4 and the protrusion 4E. The lower portion of the inner pot 4, which is located further below, is further heated by the radiant heat from the electric heater 5.

Experimental results in this embodiment are shown in FIGS. 3 and 4. The graph of FIG. 3 shows the temperature change of each part at the time of rice cooking after absorbing water, the solid line shows the detection point A shown in FIG. 4, that is, the detection temperature of the inner surface of the protrusion 4E, and the broken line shows 4 shows the detection point B shown in FIG. 4, that is, the detection temperature of rice in the approximate center of the inner pot 4. As is clear from the graph of FIG. 3, when the electric heater 4 is energized, the temperature detected at the detection point B is maintained at the boiling temperature of 100 ° C. by the water contained in the inner pot 4 together with the rice. Point A
It was confirmed that the detected temperature of 1 was raised to 105 ° C., which is higher than the boiling temperature of 100 ° C., by the radiant heat emitted to the heating space 9 below the protrusion 4E.
In order to remove excess water, it is necessary to keep the temperature high for a certain period of time after the rice is cooked, so that it is possible to efficiently perform the process after the rice is cooked without using the electric heater 5. Become.

As described above, also in this embodiment, similarly to the first embodiment, the protrusion 4E is formed only on the outer surface of the side portion 4C forming the inner hook 4, and the lower portion than the protrusion 4E is formed. With the radiant heat emitted to the heating space 9 of the above, the lower portion of the inner pot 4 is wrapped and high-temperature and uniform heating can be performed. Further, by bringing the protrusion 4E of the inner pot 4 into contact with the stepped portion 2C of the outer pot 2, it is possible to prevent heat from escaping from the heating space 9 to the outside, and it is possible to enhance the heating efficiency for the inner pot 4. Become.

Next, the third to fifth embodiments of the present invention will be described with reference to FIG.
It will be described with reference to FIG. In each of these embodiments, the same parts as those in the first and second embodiments are designated by the same reference numerals, and detailed description of the common parts will be omitted.

The third embodiment shown in FIG. 5 is formed so that the side portion 4C of the inner pot 4 and the side portion 2A of the outer pot 2 are substantially parallel when the inner pot 4 is housed. Further, in the fourth embodiment shown in FIG. 6, the projection 4E has a substantially triangular cross section, and in the fifth embodiment shown in FIG. 7, the projection 4E has a rectangular cross section. It is a thing. The protrusion 4E in the third to fifth embodiments is obtained by forming a part of the side portion 4C of the inner hook 4 to have an uneven thickness over the entire circumference, whereby the same action and effect as in the first embodiment can be obtained. Can play. In these third to fifth embodiments, the step portion 2C is formed on the side portion 2A of the outer pot 2 as in the second embodiment, and the step portion 2C is formed.
Alternatively, the protrusion 4E of the inner hook 4 may be brought into contact with the inner hook 4.
Further, it is preferable that the protrusion 4E of the inner hook 4 and the side portion 2A of the outer hook 2 have a slight gap when the inner hook 4 is housed, in consideration of thermal expansion and the like. The gap formed between the protrusion 4E and the side portion 2A can prevent the inner hook 4 from being taken out of the outer hook 2.

The present invention is not limited to the above embodiment, and various modifications can be made within the scope of the present invention. For example, the method for heating the inner pot is not limited to the one using heat transfer from the heating body or the radiant heat described in the embodiment, and for example, a blower fan may be provided to dissipate the heat from the heat-generating heater. May be.

Further, in the embodiment, the inner pot 4 is provided with the inclined portion 4B, but the side portion 4 is formed from the bottom portion 4A through the inclined portion 4B.
A continuous R portion may be formed such that the portion reaching C has a substantially spherical shape.

[0019]

The rice cooker of the present invention is provided with an inner pot for containing cooked food, an outer pot for accommodating the inner pot so that the inner pot can be inserted and removed, and an inner pot provided at the inner bottom of the outer pot for heating the inner pot. In the rice cooker having a heating means for performing, a protrusion is formed over the entire circumference at a substantially intermediate portion between an upper end and a lower end of a side outer surface of the inner pot, and the protrusion is located below the protrusion of the inner pot. Since the heating space is formed between the outer pot and the inner pot, the inner pot can be heated uniformly at a high temperature with an inexpensive structure.

[Brief description of drawings]

FIG. 1 is a sectional view of a rice cooker showing a first embodiment of the present invention.

FIG. 2 is a sectional view of a rice cooker showing a second embodiment of the present invention.

FIG. 3 is a graph showing a temperature change of each part of the above.

FIG. 4 is a schematic explanatory diagram showing measurement points of the same as above.

FIG. 5 is a cross-sectional view of an essential part showing a third embodiment of the present invention.

FIG. 6 is a cross-sectional view of an essential part showing a fourth embodiment of the present invention.

FIG. 7 is a cross-sectional view of an essential part showing a fifth embodiment of the present invention.

[Explanation of symbols]

 2 Outer pot 4 Inner pot 4C Side 4E Projection 5 Electric heater (heating means) 9 Heating space

Claims (1)

[Claims] 1. A rice cooker having an inner pot for containing a rice to be cooked, an outer pot for accommodating the inner pot so that the inner pot can be inserted and removed, and a heating means provided at an inner bottom portion of the outer pot for heating the inner pot. In the container, a protrusion is formed over the entire circumference at a substantially middle portion between the upper end and the lower end of the side outer surface of the inner pot, and the outer pot and the inner pot are located below the protrusion of the inner pot. A rice cooker characterized by forming a heating space between the rice cookers.