JP2003102620A - Lid heater structure for electric rice cooker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent dew condensed on a heat radiation plate from falling on rice and altering it in the case of using a stainless material or the like of low heat conductivity as the heat radiation plate regarding a lid structure of an electric rice cooker for which the heat radiation plate on which a heater is mounted is arranged on an inner surface of a lid. SOLUTION: A heat conduction layer 17 is formed of a metal material such as aluminum foil of high heat conductivity on an upper surface of the heat radiation plate 5 formed on the stainless material or the like of the low heat conductivity and the heater 6 is arranged on it. Heat of the heater 6 is transmitted to the entire surface of the heat conduction layer 17 and transmitted from the heat conduction layer 17 to the heat radiation plate 5. Since the heat is transmitted from the heat conduction layer 17 to the heat radiation plate 5 even at a part away from the heater, the entire surface of the heat radiation plate is relatively uniformly heated and dew condensation is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION In an electric rice cooker, water droplets adhering to the inner surface of the lid may drop on the rice in the pot during heat retention, and the rice may deteriorate due to its water content. In order to prevent this phenomenon, it has been conventionally practiced to dispose a heat dissipation plate having a heater mounted on the inner surface of the lid to prevent dew condensation on the inner surface of the lid. The present invention relates to a lid heater structure in an electric rice cooker provided to prevent the above-mentioned dew condensation.

[0002]

2. Description of the Related Art Conventionally, an aluminum material having a high thermal conductivity has been used as a heat radiating plate arranged on the inner surface of a lid.
However, in recent years, a stainless steel material, which has a cleaner appearance and is more aesthetically pleasing, has been often used as a heat sink. In that case, since the thermal conductivity of the stainless steel material is smaller than that of the aluminum material, it has been found that dew condensation is likely to occur in a portion distant from the heater, particularly in a vapor discharge mechanism portion in which the heater cannot be arranged. Therefore, the applicant of the present invention arranges a heat transfer plate made of a metal material having excellent thermal conductivity on the inner surface of the heat dissipation plate of the steam discharge mechanism to prevent dew condensation on the part (Japanese Patent Laid-Open No. 2000-
70128) is being developed.

[0003]

When an aluminum material is used as the heat dissipation plate as in the prior art, the entire heat dissipation plate is heated to a relatively uniform temperature by the heater because the aluminum material has a high thermal conductivity. Therefore, the dew condensation on the inner surface of the lid could be effectively prevented. However, if a metal material with low thermal conductivity such as stainless steel is used as the heat dissipation plate, a temperature difference may occur between the portion directly below the heater and the portion away from the heater, and dew condensation may occur in the low temperature portion. is there. It has been found that this dew condensation phenomenon may occur not only in the area where the heater cannot be arranged, but also in the heater arrangement area, which is a little away from the heater. In view of such an actual situation, the present invention aims to heat the entire surface of the heat sink more uniformly and prevent dew condensation on the surface of the heat sink.

[0004]

In order to achieve the above object, the present invention is an electric rice cooker in which a heat dissipation plate 5 having a heater 6 mounted therein is disposed on the inner surface of a lid 3, and the heat dissipation plate 5 is provided on the inner surface of the electric rice cooker rather than the heat dissipation plate. The heat conducting layer 17 was formed by disposing a metal material having a high heat conductivity, and the heater 6 was mounted thereon.
As a result, the heat of the heater 6 propagates through the heat conducting layer 17 and spreads over the entire surface, so that the entire surface of the radiator plate is relatively uniformly heated through the heat conducting layer.

Specifically, an aluminum foil is used as the heat conductive layer 17 disposed on the heat dissipation plate 5, and the aluminum foil is attached to the heat dissipation plate with the double-sided adhesive sheet 16 to form the heat conduction layer. Place the heater on top. Further, another aluminum foil 18 is attached to the upper surface of the heater 6 using the double-sided adhesive sheet 19 to fix the heater in place. Thereby, the present invention can be easily implemented. At this time, the double-sided adhesive tape 19 on which the aluminum foil forming the heat conduction layer 17 and the other aluminum foil 18 covering the upper surface of the heater are adhered, the double-sided adhesive sheet 16 is interposed by omitting the portion directly below the heater 6. Heater 6 without
When the aluminum foil which is the heat conductive layer 17 is brought into contact with the heat conductive layer 17, the heat of the heater is more efficiently transferred to the heat conductive layer.
The heat sink can be effectively heated.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a lid heater structure in an electric rice cooker according to the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a side view of the entire electric rice cooker, a part of which is cut. In this electric rice cooker, an upper surface of a pot 2 arranged inside a rice cooker body 1 is covered with a lid 3 which can be opened and closed, and a rice cooker 4 cooks cooked rice.

The lid 3 covering the upper surface of the kettle 2 is provided with a radiator plate 5 having a heater 6 mounted on the inner surface (lower surface) of the lid facing the inside of the kettle, and a packing 7 attached to the radiator plate 5 is attached to the upper end of the kettle 2. By closely contacting with the rim, the space inside the pot is sealed to enable efficient cooking of cooked rice. The steam and oneeva generated during rice cooking are through holes 9 formed in the heat dissipation plate 5.
To pass through the steam discharge mechanism 8 to be discharged to the outside of the machine. The steam discharging mechanism of the illustrated example is provided with the Oneva separation structure so that only the steam is discharged to the outside of the machine and the spillage is prevented. As a result of the vapor discharge mechanism 8 having the Oneva separation structure, the vapor discharge mechanism occupies a relatively large space in the entire plane of the heat dissipation plate 5.

The heater 6 disposed on the inner surface of the lid 3 is energized during rice cooking to prevent dew condensation on the inner surface of the lid after rice cooking. Further, even when the temperature is kept warm, an appropriate amount of electricity is supplied to prevent dew condensation on the inner surface of the lid. Further, in order to maintain the temperature of the rice in the cooker 2 at a uniform temperature, a barrel heater 11 is provided on the inner barrel 10 inside the main body so that the barrel portion of the cooker 2 can be heated. With the above-described basic configuration of the rice cooker, after cooking the rice with large heat of the rice cooking heater 5, the heat of the body heater 11 and the heater 6 attached to the heat dissipation plate 5 keeps the rice in the pot 2 constant. It can be kept warm to the temperature.

FIG. 2 is a perspective view of a radiator plate set A facing the inside of the pot, and FIG. 3 is an exploded perspective view of the radiator plate set.
The heat radiating plate 5 is formed in a dish shape from a metal material having a good appearance such as stainless steel, and ribs 12 for mounting the packing 7 are projected on the outer circumference of the body, and the ribs are dispersed all around the upper end of the body. The stop claws 13, 13 are projected so that they can be attached to the back cover 3a of the cover 3 by the locking claws 13. Also, the heat sink 5
A heat transfer plate 14 having a larger thermal conductivity than that of the heat dissipation plate is fixed to the flat portion of the above portion where the vapor discharge mechanism is arranged, and a through hole 9 is provided through the heat transfer plate 14. There is. Then, as shown in FIG. 1, the packing 15 of the steam discharging mechanism 8 is brought into close contact with the surface of the heat transfer plate 14 to form a passage of the steam discharging mechanism which maintains airtightness.

On the inner surface of the heat radiating plate 5, almost the entire surface except for the heat transfer plate 14 is covered with a double-sided adhesive sheet 16 of a metal material having a high thermal conductivity, such as a thin plate or foil of aluminum, copper or an alloy thereof. Aluminum foil is a heat conductive layer
Stick as 17. Double-sided adhesive sheet 19 on top of heat-conducting layer 17
Is arranged, the heater 6 is arranged in a meandering state thereon, and the aluminum foil 18 is stuck on the heater 6 to fix the heater 6 at a fixed position. Except for the heat transfer plate 14 portion, the above-mentioned heat conduction layer is attached, so that the double-sided adhesive sheets 16, 19 and the heat conduction layer 17, the aluminum foil 18 have through holes of the same size, 16a, 17a, 18a, 19a. Have been drilled. As a result, the packing 15 of the steam discharge mechanism is attached to the heat transfer plate 14.
Keep the surface tight and keep it airtight.

With the above structure, the heat dissipation plate set A has a sectional structure shown in FIG. That is, the heat conductive layer 17 is placed on the heat sink 5 made of stainless steel and is located on the lowermost surface facing the inside of the pot via the double-sided adhesive sheet 16, and the aluminum foil is placed on the heat conductive layer 17 via the double-sided adhesive sheet 19. 18 is located. Then, the heater 6 is held between the uppermost aluminum foil 18 and the double-sided adhesive sheet 19 therebelow.

Part of the heat generated by the heater 6 passes through the double-sided adhesive sheet 19 as shown by the arrow A in FIG.
While being transmitted to the heat conducting layer 17, the heat conducting layer 17 is spread over the entire surface, passes through the double-sided adhesive tape 16 and is transmitted to the heat radiating plate 5 as shown by an arrow B, and heats the heat radiating plate 5. At the same time, a part of the heat generated by the heater 6 is transmitted through the surface of the aluminum foil 18 on the surface as indicated by the arrow C, and even at a position away from the heater 6 as indicated by the arrow D, both sides are adhered from the aluminum foil 18. It is transmitted to the heat conduction layer 17 through the sheet 19. Since the heat generated by the heater 6 is transmitted to the heat radiating plate 5 while spreading over the entire surface of the heat conducting layer 17, the heat radiating plate 5 is heated to a relatively uniform temperature over the entire surface thereof with little temperature unevenness. In other words, a low temperature region that causes dew condensation does not occur on the surface of the heat dissipation plate 5, temperature unevenness is eliminated, and a partial dew condensation phenomenon can be prevented.

In the above structure, the double-sided adhesive sheets 16, 19
Comparing the thermal conductivity of the heat conductive layer 17 and the aluminum foil 18, the thermal conductivity of the double-sided pressure-sensitive adhesive sheet is much smaller. Therefore, the speed at which heat is transmitted through the heat conductive layer 17 is higher than the speed at which heat is transmitted through the double-sided adhesive sheet 16 to the heat dissipation plate 5. Therefore, by the presence of the double-sided adhesive sheet 16,
The entire heat conductive layer is easily heated to a more uniform temperature, which promotes the effect of eliminating the temperature unevenness of the heat dissipation plate 5.

On the other hand, the presence of the double-sided adhesive sheet 19 between the heater 6 and the heat conduction layer 17 means that the heater 6 is not
It becomes an element that hinders the transfer of heat to the aluminum foil 17, and a large amount of heat is transferred to the aluminum foil 18 located at the top. Therefore, in order to transfer the heat of the heater 6 to the heat conduction layer 17 more efficiently, if a part of the double-sided pressure-sensitive adhesive sheet 19 interposed between the heater 6 and the heat conduction layer 17 is omitted, the heat from the heater 6 will be reduced. The efficiency of heat transfer to the conductive layer 17 can be improved. However, if the double-sided adhesive sheet 19 is completely omitted, the aluminum foil 18 for fixing the heater 6 cannot be attached. In view of this, the embodiment shown in FIGS. 5 and 6 devised a structure in which an aluminum foil 18 for fixing the heater 6 was adhered and the efficiency of heat transfer from the heater 6 to the heat conduction layer 17 was improved.

In the embodiment shown in FIG. 5, the double-sided adhesive sheet 19 for adhering the heat conducting layer 17 and the aluminum foil 18 with the heater 6 sandwiched therebetween is provided with cut holes 20 along the arrangement pattern of the heaters 6. . The difference between the embodiment shown in FIG. 3 and the embodiment shown in FIG. 5 is that the heater 6 is attached to the double-sided adhesive sheet 19 on which the heat conductive layer 17 and the aluminum foil 18 for pressing the upper surface of the heater 6 are attached.
It is whether or not to provide the cut holes 20 along the arrangement pattern.

The cross-sectional structure of the heat dissipation plate set A of the embodiment shown in FIG. 5 is as shown in FIG. In this structure, the heater 6 and the heat conducting layer 17 are in contact with each other without the double-sided adhesive sheet. Therefore, the heat generated by the heater 6 is directly transferred to the heat conductive layer 17 as shown by the arrow A, and the heat transferred to the wide surface of the heat conductive layer 17 is transferred to the heat dissipation plate 5 through the double-sided adhesive sheet 16. Of course, a part of the heat is transmitted through the upper aluminum foil 18, passes through the double-sided adhesive sheet 19 from the aluminum foil 18, and is transmitted to the heat conduction layer 17. However, a part of the heat transmitted to the aluminum foil 18 on the upper surface is naturally radiated to the space inside the lid. In the structure of the embodiment shown in FIGS. 5 and 6, as a result of the heat of the heater 6 being easily transferred to the heat conduction layer 17, the amount of heat transferred to the aluminum foil 18 on the upper surface can be reduced, and the heat dissipation plate 5 can be efficiently heated. The temperature of the internal space of the lid 3 will be kept low. This is advantageous, for example, when arranging devices that dislike heat inside the lid.

[0017]

According to the lid heater structure of the electric rice cooker of the present invention as set forth in claim 1, the heat of the heater is transferred to the heat conductive layer disposed on the heat dissipation plate, and transferred from the heat conductive layer to the heat dissipation plate.
Therefore, even if the heat sink is made of a stainless steel material having a low thermal conductivity, the entire surface can be heated to a relatively uniform temperature, and a portion near the heater and a portion apart from the heater in the area where the heater is arranged are separated. It is possible to reduce the temperature difference between the two and avoid a situation in which dew drops on the rice that is being kept warm due to the partial dew condensation phenomenon and the quality of the rice is altered.

According to the second aspect of the invention, the lid heater structure according to the first aspect can be easily implemented. Since the double-sided pressure-sensitive adhesive sheet located between the heat sink and the aluminum foil, which is the heat-conducting layer, has low thermal conductivity, sufficient heat is transferred to the heat-conducting layer in the part away from the heater, and the heat conduction This has the effect of heating the layers and thus the entire surface of the heat sink to a more uniform temperature.

According to the third aspect of the invention, in addition to the effect of the second aspect of the invention, heat can be efficiently transmitted from the heater to the heat conduction layer, the thermal efficiency is improved, and the temperature inside the lid rises. Has the effect of keeping it as low as possible. This is advantageous when an operating device or display device that dislikes heat is built in the lid.

[Brief description of drawings]

FIG. 1 is a side view of the whole rice cooker with a part cut away,

FIG. 2 is a perspective view of a radiator plate set having a structure according to the present invention,

3 is an exploded perspective view of the heat dissipation plate set of FIG. 2,

FIG. 4 is an enlarged sectional view of only a part of the heat sink set of FIG.

FIG. 5 is an exploded perspective view of a heat dissipation plate set according to another embodiment.

6 is an enlarged cross-sectional view of only a part of the heat dissipation plate set of the embodiment shown in FIG.

[Explanation of symbols]

1 ... rice cooker body, 2 ... pot, 3 ... lid, 3a ... back lid,
4 ... rice cooking heater, 5 ... heat sink, 6 ... heater, 7 ...
Packing, 8 ... Steam discharging mechanism, 9 ... Through hole, 10 ... Inner case, 11 ... Body heater, 12 ... Rib, 13 ... Locking claw, 14 ...
Heat transfer plate, 15 ... Packing, 16, 19 ... Double-sided adhesive sheet, 17 ... Heat conductive layer, 18 ... Aluminum foil, 20 ... Cut hole, A ... Heat sink set.

Continued front page    F-term (reference) 4B055 AA03 BA22 BA54 BA63 CA21                       CA71 CC43 CC45 DA04 DB01                       FA09 FB01 FB02 FC08

Claims (3)

[Claims] 1. In an electric rice cooker in which a heat dissipation plate equipped with a heater is arranged on the inner surface of a lid, a heat conduction layer is formed by disposing a metal material having a higher thermal conductivity than the heat dissipation plate on the heat dissipation plate. A lid heater structure in an electric rice cooker characterized in that a heater is disposed on the heat conducting layer to heat the heat sink through the heat conducting layer. 2. A heat-conducting layer disposed on the heat-dissipating plate is an aluminum foil, the aluminum foil is adhered to the heat-dissipating plate with a double-sided adhesive sheet, and a heater is provided on the aluminum foil forming the heat-conducting layer. The lid heater structure in an electric rice cooker according to claim 1, wherein the heater is fixed and the upper surface of the heater is fixed in place by adhering another aluminum foil to the upper surface of the heater with a double-sided adhesive sheet. 3. A double-sided pressure-sensitive adhesive tape comprising an aluminum foil for forming a heat-conducting layer and an aluminum foil other than the aluminum foil, wherein the portion directly below the heater is omitted, so that the heater and the heat-conducting layer are not interposed. The lid heater structure in the electric rice cooker according to claim 2, wherein the aluminum foil forming the sheet is contacted.