JPS63267312A - 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 Field of Application of G-beam The present invention relates to a rice cooker used in general households.

Conventional technology Traditionally used as an electric heater for rice cookers.

■ Sheathed heater is cast into aluminum.Aluminum cast-in heater.

■ Sheathed heater (for temperature).

Two are mainly used. When using the Ayumi cast-in heater (■), a direct heating method is used in which the pot and electric heater come into direct contact, and when using a sheathed heater (■), an indirect heating method is used where the pot and electric heater do not come into contact. The actual situation is that the positions of the pot and electric heater are changed depending on the electric heater used.

However, in the direct heating method using a cast-in aluminum heater, the pot and electric heater are in contact with each other, so although the heat efficiency is excellent, the heat transfer from the electric heater to the pot is mainly due to conduction. Because of this, depending on the degree of contact between the pot and the electric heater, there is an imbalance in heat transfer depending on the location, such as a part of the temperature sensor installed in the center of the electric heater or the top of the pot.

There was a problem that the rice tends to be unevenly cooked and the overall taste is poor.

In addition, since the electric heater and pot require strict dimensional accuracy to ensure tight contact between the electric heater and the pot, if an imbalance in heat transfer occurs due to deformation or corrosion during use, uneven cooking may occur. The problem was that it was getting worse.

On the other hand, in the indirect heating method using a high-temperature type sheathed heater (■), heat transfer from the electric heater to the pot occurs through thermal radiation, so the part 1 m closer to the electric heater becomes soft, and the part far from the electric heater (pot) There was a problem in that the center part of the rice cake was cooked unevenly, such as hardness, and the taste of the food deteriorated.

Furthermore, if the sheathed heater is made into a spiral shape in order to improve this problem, it will require modification to improve the flatness of the heater and fixing fittings, which will increase the cost. Also, the heating area of the heater is small.

This has the disadvantage that the temperature of the heater itself becomes high, and that the heat shielding structure of the cooker body also needs to be large-scale.

Therefore, in order to solve these problems, the inventor of the invention developed a top plate 30 in the shape of a reverse circular shape, which is made of a metal plate and has a hole 80a in the center, as shown in FIG.

It has a spirally wound double heating wire 81, a groove 82a in which the heating wire 31 is spirally arranged, and a hole a2b in the center, and is made of a heat insulating material mainly composed of silica-alumina fibers. A heat insulating base 82, a cylindrical storage case 38 that houses the heat insulating base 82 and has a bottom with a hole aaa in the center, and the top plate 80 and the storage case 88 are provided in their respective centers. An electric heater is proposed that includes a fixing ring 34 that is inserted into the holes 30a and 38a and fixed.

Furthermore, a rice cooker using the above-mentioned electric heater is also proposed in which the pot, the electric heater, and the pot are located apart from each other with a certain heating space. This rice cooker is structurally similar to the conventional indirect heating method using a sheathed heater, but unlike the conventional rice cooker, which uses wire heating, it uses single-sided heating.
The pot can be heated more evenly. For this reason, 1!
The heat transfer from the air heater became ideal, and the uneven cooking, which had been a problem in the past, was significantly improved, and the taste of the rice was also improved, resulting in significant improvements in rice cooking performance.

Problems to be Solved by the Invention However, in the above-mentioned rice cooker using the m-air heating method, the thermal efficiency is inferior, as in the case of the indirect heating method using a sheathed heater. ■The temperature of the rice cooker becomes high. Although it has excellent rice cooking performance, there are some problems.

In reality, the above two drawbacks have become major problems.

An object of the present invention is to solve the above-mentioned problems and provide a rice cooker that has excellent rice cooking performance, thermal efficiency, and heat insulation properties for the rice cooker body.

Means to solve problems In order to solve the above problems, the rice cooker of the present invention is provided.

A top plate made of a metal plate and a heating wire wound in a spiral shape.

It has a groove in which the heating wire is arranged in a spiral shape, and
An electric heater consisting of a heat insulating base made of a heat insulating material mainly composed of alumina fibers, a storage case made of a metal plate that houses the heat insulating base, a pot that houses the food to be cooked, and a protection housing that houses the pot. 01 protective frame and OM
A heating space is provided between the heating space and the protective frame, and the electric heater is connected to the bottom of the protective frame within the heating space through a disc-shaped heater fixing base between the heater and the pot and the heater fixing base. and between the heater fixing base and the bottom of the protective frame.

Function In the above configuration, the electric heater used has a much wider heating area compared to the conventional indirect heating method using a sheathed heater, so that the pot can be heated evenly and uneven cooking can be avoided. Decrease.

Moreover, the electric heater is attached to the bottom of the protective frame via the disc-shaped heater fixing base in the heating space, between the bottom of the pot, between the heater fixing base, and between the heater fixing base and the bottom of the protective frame. Since they are installed at a predetermined interval to form an air layer, the heater fixing base stops heat radiation from the 1m electric heater to the protective frame and heat conduction between metals, and also prevents the electric heater and the heater from being fixed. Each air layer between the base and the bottom of the protective frame stops the heat transfer by air convection, reducing the heat transfer from the electric heater to the protective frame, suppressing the temperature rise of the protective frame, and thus reducing the temperature of the rice cooker. Temperature can be kept low. As a result, heat transfer to the pot improves and thermal efficiency improves.

Example An embodiment of the present invention will be described below based on the drawings.

FIG. 1 is a partially cutaway side view of a rice cooker according to an embodiment of the present invention. In FIG. 1, the rice cooker main body l has a substantially cylindrical shape and has a bottom plate, and is open at the top. A protective frame 8 having a bottom portion is provided. The inner side surface of the protective frame 8 is painted black. An annular upper frame 4 made of heat-resistant plastic is fitted onto the inner peripheral surface of the upper end of the rice cooker main body l, and the outer peripheral surface of the upper end of the protective frame 8 is fitted into the upper frame 4. A pot 5 is removably housed inside the protective frame 8. A flange 6 is formed outwardly at the edge of the upper opening of the pot 5, and by placing the flange 6 on the upper surface of the upper frame 4, the pot 5 is stably housed inside the protective frame 8.

An electric heater 7 is installed below the pot 5 in a heating space 8 formed between the bottom of the protective frame 8 and the bottom of the vortex 5. As shown in FIG. 2, the electric heater 7 includes a top plate 7a made of stainless steel (SO8804), a heat insulating base 7b made of silica fiber as a main component, a heating wire 7C, and the heat insulating base 7b. The top plate 7a is formed with a storage case 7d made of stainless steel (SO5480) for storing the base plate 7b, and the top plate 7a is provided with claws 7e bent inwardly at six locations on the side edges in a lid shape. A hole is formed in the center, and the entire body has a convex R2000 spherical press and is coated with a heat-resistant coating. The heat insulating base 7b is provided with a spiral groove 7f and a hole in the center, and the heating wire 7c is arranged along the spiral inside the s7f. The storage case 7d has a hole in the center and six square holes 7g in the side edges, with which the claws 7e engage when fitted with the top plate 7a. will be combined. Assembling the electric heater 7
The heating wire 7c is stored in the heat insulating base 7bft arranged inside the It 7f and the storage case 7d, the top plate 7a is placed over the top, the claw part 7e is locked in the square hole 7g, and the central part What is necessary is to penetrate each company and insert the fixing ring 7h to integrate them.

The electric heater 7 has a disk-shaped heater fixing stand (
9), an air layer ga is provided at a predetermined interval between the pot 5 marked 0 above, between the heater fixing base 9 below, and between the heater fixing base 9 and the protective frame 1. , sb and 8c are formed. A heat-sensitive element 1O for detecting the end temperature of rice cooking is disposed in the center of the heating space 8, and is attached to the protection frame 3. ball,
At U%1 between the bottom of the cooker body l and the bottom of the protective frame 8, there is a microswitch 12 that is turned on and off by a lever 11 interlocking with the heat-sensitive element 1G to control energization of the electric heater 7. It is arranged. Furthermore, a 1 display plate 18 is attached to the side surface of the rice cooker main body l, and the button 14 is attached to the lever 11. Further, a lid 15 is attached to the opening of the rice cooker body l so as to be openable and closable.

The operation of the above rice cooker will be explained. First, washed rice and water are placed in the pot 5, the pot 5 is housed inside the protective frame 3, and the lid 15 is closed. When the button 14 is pressed, the lever 11 is rotated, and the heat-sensitive element 10 linked to the lever 11 is operated, and the rice is in the cooking state.

Micro switch 12 is turned on and t! ! The air heater 7 is energized. When the electric heater 7 generates heat, the air inside the sealed heating space 8 is heated, and the pot 5 is heated through this heated air. Then, the rice is cooked by heating the pot 5, and when all the water inside the pot 6 is absorbed by the rice and disappears, the bottom of the pot 5 becomes empty and the temperature rises rapidly. At this time, the temperature of the heat sensitive element 10 also rises, the lever 11 is pushed down, and the micro switch 1
2 is open.

The electricity to the electric heater 7 is stopped, and rice cooking is completed.

In the above rice cooker, the heat generating area of the electric heater 7 is made into a wider area than when using a conventional sheathed heater, so that the pot 5 can be heated uniformly and there is less uneven cooking. 7 is attached to the bottom of the protective frame 8 via a disc-shaped heater fixing base 9 inside the heating space 8 .
Since the heater is installed with a space provided between it and the bottom of the heater fixing base 9, between the heater fixing base 9 and the bottom of the protective frame 8, and forming air Jm8a, 8b, 8c, Protective frame 8 from electric heater 7 and rice cooker body l
The heat transfer to the rice cooker is reduced, temperature rise is suppressed, and thermal efficiency is increased, making it possible to efficiently cook delicious rice.

The thermal efficiency and the temperature of the rice cooker main body 1 of the rice cooker of the above example were evaluated in comparison with a conventional rice cooker not equipped with a heater fixing stand, and the results are shown in Table 1. In addition,
Regarding thermal efficiency, it is 1.84! The evaluation was made by measuring the cooking time required to cook rice at a constant power consumption.

As is clear from the results shown in Table 1, the tX heater 7
air layers 8a and 8b via the heater fixing table 9.

8c were respectively formed and attached to the bottom of the protective frame 8.

The rice cooker of the above embodiment has a shorter rice cooking time and higher thermal efficiency than the conventional rice cooker, and the temperature of the rice cooker main body 1 is kept low, so that it has excellent heat shielding properties.

Effects of the Invention As described above, the rice cooker of the present invention mainly includes a top plate made of a metal plate, a spirally wound heating wire, and silica-alumina fibers having a groove in which the heating wire is arranged in a spiral shape. An electric heater consisting of a heat insulating base made of a heat insulating material and a storage case made of a metal plate that houses the heat insulating base is located at the bottom of the protective frame in the heating space formed between the protective frame and the pot. The electric heater, the heater fixing base, and the protective frame are each installed at a predetermined interval through a disc-shaped heater fixing base, and an air layer is formed in each of them, so that the electric heater can be heated evenly. The rice cooking performance is very good, as it heats up evenly and cooks delicious rice.Moreover, the heat transfer from the electric heater to the protective frame is reduced, suppressing the rise in temperature of the protective frame and the rice cooker itself. At the same time, heat transfer to the pot is increased, and thermal efficiency and heat shielding properties for the rice cooker body are also significantly superior.

[Brief explanation of drawings]

Fig. 1 is a partially cutaway side view showing a rice cooker according to an embodiment of the present invention, Fig. 2 is a sectional view of the electric heater of the same rice cooker, and Fig. 8 is an exploded perspective view of a conventional electric heater. be. 2...Insulating material, 8...Protection frame, 5...Platform, 7...
・Electricity and -ta, 7a...Top plate, 7b...Insulation base,? C... Heating wire? d...Storage case, 7f...
-Groove, 8... Heating space section, 9... Heater fixing stand.

Claims (1)

[Claims] 1. A top plate made of a metal plate, a spirally wound heating wire,
It has a groove in which the heating wire is arranged in a spiral shape, and
An electric heater consisting of a heat insulating base made of a heat insulating material mainly composed of alumina fibers, a storage case made of a metal plate that houses the heat insulating base, a pot that houses the food to be cooked, and a protection housing that houses the pot. A heating space is provided between the protective frame and the pot, and the electric heater is attached to the bottom of the protective frame in the heating space through a disc-shaped heater fixing base. and the heater fixing base, and between the heater fixing base and the bottom of the protective frame.