JPS63296705A - Rice cooker - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a rice cooker used in general households.
In particular, it relates to a rice cooker with improved cooking performance using an electric heater.

Conventional technology Conventionally, there are two main types of electric heaters used in rice cookers: (1) a cast aluminum heater in which a sheathed heater is embedded in cast aluminum, and (2) a sheathed heater (high temperature type). When using the cast aluminum heater in 1), a direct heating method is used where the pot and electric heater come into direct contact, and when using the sheathed heater in (2), indirect heating is used where the pot and electric heater do not come into contact. The actual situation is that the position of the pot and electric heater is changed depending on the type of electric heater used.

Problems to be Solved by the Invention However, in the direct heating method (1) using an aluminum cast heater, the pot and electric heater are in contact with each other, so although it is superior in terms of thermal efficiency, Because heat transfer to the pot occurs through thermal conduction, an imbalance in heat transfer may occur depending on the degree of contact between the pot and the electric heater, or depending on the location such as the temperature sensor installed in the center of the electric heater or the top of the pot. As a result, the phenomenon of uneven cooking of rice tends to occur, and there is a problem that the overall taste deteriorates.

In addition, strict dimensional accuracy is required to ensure that the electric heater and pot are in close contact with each other, which increases costs and causes deformation or corrosion during use.If heat transfer becomes unbalanced, uneven cooking becomes more likely. The problem was that it was getting worse.

On the other hand, in the indirect heating method (2) that uses a high-temperature type sheathed heater, heat transfer from the electric heater to the pot occurs through thermal radiation, so the parts near the electric heater become sticky and There was a problem in that the part farther away from the heater (the upper part of the pot) had uneven cooking, such as hardness, and the taste deteriorated.

Furthermore, in order to improve this, if the sheathed heater is made into a spiral shape, it will require modification to improve the flatness of the heater and fixing metal fittings, which will increase the cost. Furthermore, since the heating area of the heater is small, the temperature of the heater itself becomes high.
As a result, the heat shielding structure of the main body also had the disadvantage of being dependent on the structure.

The present invention has been made to solve the above problems, and aims to provide a rice cooker that is inexpensive and capable of ideal heating without requiring strict dimensional accuracy. be.

Means for Solving the Problems In order to solve the above problems, the present invention has a spirally wound heating wire and a groove in which the heating wire is arranged in a spiral shape.
The electric heater is composed of a heat insulating base made of a heat insulating material mainly composed of silica-alumina fibers, and a storage case that houses the heat insulating base, and the outer circumferential surface of the electric heater is black-treated and is suitable for cooking food. The pot to be stored and this pot to be stored,
and a protective frame that is black-treated on the inside, the electric heater is attached to the outside of the protective frame, and a heating space is formed around the pot by the protective frame. It is.

Function: In the rice cooker of the present invention, since the electric heater is attached to the outside of the protective frame, the heat of the electric heater is easily transferred to the protective frame, and the entire protective frame is treated as a single heating source. It's working. For this reason, it is structurally similar to the indirect heating method using a conventional sheathed heater, but unlike the conventional method which uses line heating, it uses surface heating, so it heats the pot more evenly. be able to. As a result, the structure is closer to that of an old-fashioned cooking stove, and the distribution of heat from the electric heater is now in an ideal state, which not only improves the taste of the rice but also significantly improves the problem of uneven cooking, which had been a problem in the past. It also has a significant effect on rice cooking performance. Furthermore, since there is no contact part between the electric heater and the pot, strict dimensional accuracy is not required, and as a result, the cost is low.

On the other hand, in terms of thermal efficiency, the protective frame and pot are treated with black, which is excellent in absorbing and radiating heat, so that heat from the electric heater is efficiently transmitted to the food being cooked.
゛In addition, since the electric heater uses a heat insulating material whose main component is silica-alumina fiber as the heat insulating base, the heat from the heating wire is efficiently transmitted to the protective frame and its movement to the bottom surface is suppressed. be done. For these reasons, the thermal efficiency does not drop significantly compared to the conventional indirect heating method using a sheathed heater.

As is clear from the above explanation, in the rice cooker of the present invention,
It does not require strict dimensional accuracy, is inexpensive, and can provide ideal heating without uneven cooking.

EXAMPLES Hereinafter, specific examples of the present invention will be described based on FIGS. 1 to 6. In the figure, reference numeral 1 denotes a substantially bottomed cylindrical main body with an open top surface, and a substantially cylindrical protective frame 3 serving as a pot storage section is disposed inside this main body 1 via a heat insulating material 2. , and the outer periphery of the upper end of the protective frame 3 is fitted into an annular upper frame 4 made of heat-resistant plastic that is fitted around the inner periphery of the upper end of the main body 1 . Reference numeral 6 denotes a pot having a flange 6 projecting outwardly at the upper opening edge;
is disposed within the protective frame 3 by placing it on the upper surface of the upper frame 4. Further, the outer peripheral surface of the pot 5 is treated with black alumite using a heat-resistant dye.

7 is an electric heater, 7a is a heat insulating base made of a heat insulating material mainly composed of silica-alumina fibers, and this heat insulating base 7a is provided with a spiral groove 7b and a hole 7a/ in the center. ing. 7C is a spirally wound heating wire, and this heating wire 7c is inserted into the groove 7b provided in the insulation board a.
It is located in

7d is a storage case made of 5US430 that stores a heat insulating board 71L on which heating wires 7C are arranged;
A hole 7d' is provided in the center of d, and
Convex lips 76,76' are provided on the inner and outer circumferential surfaces.

The electric heater 7 described above is attached and integrated to the outside of the protective frame 3 by using a storage case 7d for the electric heater 7.

Further, a heating space 8 is provided between the electric heater 7 and the pot 6.

Reference numeral 9 denotes a sensing element for detecting the end temperature of rice cooking, which is attached to the protective frame 3. Reference numeral 1o indicates a lever that is interlocked with the heat-sensitive element 9, and reference numeral 11 indicates a microswitch that controls the energization of the electric heater 7. This microswitch 11 is turned on and off by the lever 1o. 12 is a display board, which is attached to the main body 1. Reference numeral 13 denotes an operation button, which is inserted into the lever 1o. Reference numeral 14 denotes a lid, which is attached to the upper opening of the main body 1 so as to be openable and closable.

Next, the operation of the rice cooker of the present invention having such a configuration will be explained. First, the washed rice 21 and water 22 are stored in the pot 6, and the pot 5 is stored in the protective frame 3.
Close the lid 14. By pressing the operation button 13, the lever 1o is rotated, and the heat-sensitive element 9 that is linked to this lever 10 is rotated.
operates to enter the rice cooking state, and the microswitch 11 is turned on to energize the electric heater 7.

When the electric heater 7 generates heat, the sealed heating space 8
The air inside is heated, and the heated air passes through the pot 6.
is heated. By heating this pot 5, rice cooking in steps f and 21 is performed. And the water 22 in the pot 6
When all of the rice is absorbed by the rice 21 and used up, the bottom of the pot 6 becomes empty and the temperature rises rapidly. At this time, the temperature of the heat-sensitive element 9 also rises, and the lever 10 is pushed down to open the microswitch 11, stopping the power supply to the electric heater 7 and completing the rice cooking.

On the other hand, in order to evaluate uneven cooking during rice cooking using the rice cooker of the present invention, the temperature/degree temperature rise curve of each part of the pot 6 shown in FIG. 3 was measured.

In Fig. 3, the outer diameter d of the pot 6 is φ220ml, point A is the center point of the top of the rice 21, point D is at the same height and 80 mm away from the center point, and point 0 is at the bottom of the pot 5. p10
The center point on ml11, the F point, is at the same height as the 0 point and 5BQmm away from the center point, the 8 point is the middle part between the E point and the 0 point, and the E point is the middle part between the D point and the F point. .

FIG. 4 shows the temperature rise curve during rice cooking (water level line is about 90 mm) at these six measurement points.

Also, for consideration, the temperature rise curve in the case of the indirect heating method using the conventional sheathed heater is also shown in the fifth section.
Shown in the figure.

In addition, in FIG. 5, A/, B/, c/,
Each part of D/, -rt/ and F' is A in FIG.
B, C: corresponds to each part of D, E and F.

As is clear from comparing FIG. 4 and FIG. 6, in the rice cooker of the present invention, there is very little temperature variation when raising the temperature and around 100"C. Therefore, in the rice cooker of the present invention,
When cooking rice, there is almost no uneven cooking that occurs in the past, and ideal heating with less uneven cooking is achieved.

Effects of the Invention As is clear from the description of the above embodiments, the present invention has a spirally wound heating wire, a groove in which the heating wire is arranged in a spiral shape, and a silica-alumina fiber. An electric heater is composed of a heat insulating base made of a heat insulating material whose main component is a heat insulating base, a storage case that houses the heat insulating base, a pot whose outer circumferential surface is black-treated and stores food to be cooked, and The electric heater is mounted on the outside of the protective frame, and the protective frame forms a heating space around the steel. To provide a rice cooker that does not require dimensional accuracy, is inexpensive, and can perform ideal heating without uneven cooking.

[Brief explanation of the drawing]

FIG. 1 is a cutaway side view of a rice cooker showing an embodiment of the present invention;
Figure 2 is a cross-sectional view of the electric heater in the same rice cooker, Figure 3 is a configuration diagram showing the temperature measurement points of each part of the pot in the same rice cooker, and Figure 4 is a temperature rise curve of each part of the pot in the same rice cooker. The graph shown in FIG. 6 is a graph showing temperature rise curves of various parts of a pot in a conventional example using a conventional sheathed heater. 3...Protective frame, 6...Pot, 7...
・・Electric heater, completion a・・・・insulation base, completion b・・
... Groove, 7C ... Heating wire, 7d ...
-Storage case, 8... Heating space. Name of agent: Patent attorney Toshio Nakao and 1 other person3-
Ichiho W na, f-Ichitsuri 7-Idenki Peeda'ya --all sexual grave board 7b--Ichizo Figure 3 Figure 4

Claims (1)

[Claims] A heat insulating base comprising a spirally wound heating wire, a groove in which the heating wire is arranged in a spiral shape, and a heat insulating material mainly composed of silica-alumina fibers, and a storage for storing this heat insulating base. The present invention includes an electric heater consisting of a case, a pot whose outer peripheral surface is treated with black and which houses food to be cooked, and a protective frame which houses the pot and whose inside is treated with black. . A rice cooker, wherein the electric heater is attached to the outside of the protective frame, and a heating space is formed around the pot by the protective frame.