JPH11137419A - Electric rice cooker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To cool electronic parts by a natural air current instead of a cooling fan. SOLUTION: An electric rice cooker is provided with a rice cooker body 1 constituted so that an inner pot 3 can be housed in its interior, and solenoid induction coils 12 and 13 are used as the heating means of the inner pot 3. While air flow inlets 23 are formed in the bottom of the rice cooker body 1, air flow outlets 24 are formed in the upper part of the rice cooker body 1, and a heat sink 7 fitted with electric parts 74 is installed in the air flow passage flowing from the air flow inlets 23 toward the air flow outlets 24 so as to be oppositely near to the air flow inlets 23. Thus, the air A flowing in through the air flow inlets 23 rises naturally toward the air flow outlets 24, and in this process the air A deprives heat from the heat sink 7 to cool the electronic parts 74.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric rice cooker, and more particularly to a cooling structure for electronic components in an electric rice cooker using an electromagnetic induction coil as an inner pot heating means.

[0002]

2. Description of the Related Art In general, in the case of an electric rice cooker using an electromagnetic induction coil as an inner pot heating means, electronic parts such as semiconductors (for example, power transistors) in a power supply unit generate heat, so that a cooling fan is provided in the rice cooker body. To cool the electronic component.

[0003]

However, when the electronic components are cooled by the cooling fan as described above, since the cooling fan needs to be operated during rice cooking, the rotation noise of the cooling fan is reduced. In addition to being annoying, there is a problem that the number of parts increases and power consumption also increases.

[0004] The present invention has been made in view of the above points, and has as its object to enable electronic components to be cooled by natural airflow instead of a cooling fan.

[0005]

In the basic structure of the present invention (the invention of claim 1), as a means for solving the above-mentioned problems, a rice cooker main body configured to be able to store an inner pot therein is provided. In the electric rice cooker using an electromagnetic induction coil as a heating means of the inner pan, an air inlet is formed at a bottom of the rice cooker main body, and an air outlet is formed at an upper part of the rice cooker main body. And, in the flow path of the air flowing from the air inlet to the air outlet,
A heat sink to which an electronic component is attached is installed in close proximity to the air inlet.

[0006] With the above configuration, the air that has flowed in from the air inlet is naturally opposed to the air inlet in the process of naturally rising toward the air outlet formed in the upper part of the rice cooker main body. The heat is taken from the installed heat sink to cool the electronic components. That is, electronic components can be cooled by natural airflow without using a cooling fan as in the related art.

[0007] As in the invention of claim 2, the rice cooker main body has an inner case in which the inner pot is housed and an outer case forming an outer body, and the inner case and the outer case. When the space formed between the inner case and the outer case is used as the air flow path, the electronic component can be cooled by effectively utilizing the space formed between the inner case and the outer case.

[0008] As in the third aspect of the present invention, a handle receiver for receiving a handle for carrying an electric rice cooker is provided at an upper portion of the rice cooker main body, and the air outlet is provided near a position below the handle receiver. When forming
The handle receiver located above the air outlet functions as an eaves for water or oneva flowing down from above, and it is possible to prevent water or oneva from entering the rice cooker main body from the air outlet.

[0009] As in the invention of claim 4, a cord reel for winding a power cord is provided at the bottom of the rice cooker main body, and the heat sink is provided in the space portion. If the air inlet is formed in a surplus space formed by the above and the air inlet is formed at a position below the surplus space, the surplus space formed by installing a code reel in a space portion in the rice cooker main body is effective. Therefore, it is not necessary to form a special space for installing the heat sink in the space inside the rice cooker main body, and the size of the rice cooker main body can be reduced.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Some preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

First Embodiment (Corresponding to Claims 1 to 4) FIGS. 1 to 4 show an electric rice cooker according to a first embodiment of the present invention.

This electric rice cooker has a double-structured rice cooker main body 1 which is configured to be able to store the inner pot 3 therein and has a space portion 4, and an upper opening of the rice cooker main body 1 can be opened and closed freely. And a cover 2 for covering.

The rice cooker main body 1 has a body 5 serving as an outer wall.
a and a synthetic resin having a shoulder 5b serving as an upper wall (for example,
An outer case 5 formed of an integrally molded product of polypropylene and serving as an exterior body, and a bottomed cylindrical shape made of a synthetic resin (for example, made of polypropylene) whose upper end is connected to an inner peripheral edge of the shoulder portion 5b by a screw 8. And a dish-shaped bottom member 7 made of synthetic resin (for example, made of polypropylene) having an upper end coupled to the lower end of the body 5a of the outer case 5. The space 4 is formed by being surrounded by the inner case 6 and the bottom member 7. Note that the inner pan 6 is housed in the inner case 6 so as to be removable.

The inner pot 3 is of a round bottom type in which a radius of curvature of a curved portion 3b from the bottom 3a to the side peripheral portion 3c is large, and a central portion of the bottom 3b has an upwardly curved curve. The protrusion 9 is formed integrally. The curved protrusion 9 is for causing internal convection (that is, convection upward of the curved protrusion 9) during rice cooking, and the external convection generated along the inner peripheral wall of the inner pot 3 and the curved protrusion are generated. 9 allows uniform heating of the contents.

A curved protruding portion 6a corresponding to the curved protruding portion 9 is also integrally formed at the center of the bottom surface of the inner case 6, and the central portion of the curved protruding portion 6a acts as a temperature detecting means. The temperature sensor 10a of the center sensor 10
A sensor hole 11 is formed for receiving the sensor hole. A center sensor 10 is provided in the sensor hole 11 such that the temperature detection unit 10a comes into contact with the lower surface of the curved protrusion 9 of the inner pan 3. On the outside of the bottom surface of the inner case 6 and the curved portion between the bottom surface and the side peripheral surface, annular electromagnetic induction coils 12 and 13 acting as heating means so as to surround the sensor hole 11.
Is installed. That is, the electromagnetic induction coil 12,
Reference numerals 13 are provided corresponding to the bottom 3a and the curved portion 3b of the inner pot 3, respectively.

The electromagnetic induction coils 12 and 13 are sandwiched between a coil die 15 fixed to the bottom surface of the inner case 6 by screws 14 and the bottom surface of the inner case 6.

The coil die 15 is, as shown in FIG.
An annular portion 15a for inserting and supporting the center sensor 10
And three coil supporting portions 15b, 15b, 15b, 15b projecting radially from the annular portion 15a and having tip portions inclined upward.
15b and a substrate support 15c integrally formed between two of the coil supports 15b, 15b, 15b, and the electromagnetic induction coils 12, 13 are provided in each of the coil supports 15b. The ferrite cores 16 and 17 are provided so as to close the apparatus so that the magnetism caused by the magnetic field does not affect the underlying equipment.

Each of the coil support portions 15b is provided with the annular portion 1
A core holder 18 extending radially from 5a and having a substantially U-shaped cross section including a horizontal portion 18a and an inclined portion 18b continuing from the horizontal portion 18a; and a core retainer 19 for closing an upper opening of the core receiver 18. The core receiver 18
The flat plate-like ferrite cores 16 and 17 of the same shape are housed in the horizontal portion 18a and the inclined portion 18b, respectively.

At the tip of the core presser 19, a locking claw 20 is formed integrally with the tip of the core receiver 18, and the locking claw 20 is engaged with the tip of the core receiver 18. The ferrite cores 16 and 17 are clamped by fixing the intermediate portion of the core retainer 19 to the tip of the horizontal portion 18a of the core receiver 18 with screws 21 in the stopped state. Therefore, the work of fixing the ferrite core with the adhesive as in the related art becomes unnecessary, and
Instead of a ferrite core having a complicated shape (that is, a curved shape) as in the related art, a flat ferrite core 16 of the same shape,
17 can be adopted, so that the ferrite cores 16 and 17
You just have to prepare the kind. Reference numeral 22 denotes a thermal fuse.

The electric rice cooker is of a fanless type that does not include a cooling fan for cooling the heat-generating electronic components 74 such as a power transistor. From the air inlet 23 formed at an appropriate position of the material 7, an upper portion of the body 5 a of the outer case 5 (for example, a handle 25 for carrying an electric rice cooker)
The flow path (for example, a position above the air inlet 23) of the rising air A flowing through the space 4 toward the air outlet 24 formed near the lower position of the handle receiver 26 for receiving the air. The heat sink 75 to which the component 74 is attached is placed so as to be close to and facing.

Further, in the present embodiment, an electric cord (not shown) is provided on the rear side of the bottom of the rice cooker main body 1 (specifically, the bottom member 7) (that is, on the hinge side of the rice cooker main body 1). ) Is formed with an upward concave portion 77 for installing a code reel 76 for winding up the heat sink 75.
7 is provided in a surplus space 78 formed at a position adjacent to and in front of. Further, the air inlet 23 is formed at a position below the surplus space 78. A heat shield 79 is provided on the upper surface of the cord reel 76, and a heat insulating space 80 is formed between the heat shield 79 and the top surface of the upward recess 77. In this way, the thermal effect on the code reel 76 can be prevented as much as possible.

The heat sink 75 is attached by screws 82 to a heat shield plate 81 arranged at a predetermined distance below the coil die 15. A predetermined interval is also maintained between the ribs 83 integrally protruding from the upper surface of the heat sink 75 so as to surround the front screw 82. The upper end of the rib 83 is formed in an arc shape, and the rib 83 and the heat shield plate 81 are in line contact with each other. By doing so, the influence of heat from the inner pot 3 on the heat sink 75 can be prevented as much as possible.

At the front edge of the air inlet 23, a rearward guide piece 23a for guiding the incoming air A to the air outlet 24 is formed integrally with the bottom member 7.

At the lower edge of the air outlet 24, an upward guide piece 24a for guiding the outflowing air A upward and covering the inside so that the inside can not be seen from the air outlet 24 is provided with the outer case 5. It is formed integrally.

The rising air A flowing through the space 4 from the air inlet 23 to the air outlet 24 takes heat from the heat sink 75 to cool the electronic component 74. By doing so, the number of parts can be reduced and the cost can be reduced, and at the same time, the operating noise (that is, the rotating noise) of the cooling fan does not occur during cooking of rice. The air outlet 24
Formed near the lower position of the handle receiver 26,
The handle receiver 26 located above the air outlet 24 acts as an eaves for water or Oneva flowing down from above,
Water or oneva can be prevented from entering the rice cooker main body 1 from the air outlet 24.

Further, the trunk 5a of the outer case 5
A microcomputer board cover 28 to which a microcomputer board 27 is assembled is attached to the upper inside of the front side. The microcomputer board cover 28 has a box shape that covers substantially the entire front and side surfaces of the front microcomputer board 27, and has an opening 2 formed at the upper front side of the outer case body 5 a.
9 is attached. That is, the locking claws 3 integrally protruded from the upper end of the microcomputer board cover 28.
1 is a locking projection 3 formed on the upper opening edge of the opening 29
In a state where the rib 32 is engaged with the boss 33, the rib 32 formed integrally with the lower end of the microcomputer board cover 28 is connected to a boss 33 formed at the lower opening edge of the opening 29 with a screw 34. The opening 29 is covered by a name plate 35 having an operation section for various switches, a liquid crystal display section (not shown), and the like. In this manner, the microcomputer board cover 2 is mounted with the microcomputer board 27 assembled.
8 can be assembled, and the microcomputer board cover 28 can be removed by removing the screw 34. Therefore, the assembling workability and after-sales property are improved.

The microcomputer board 27 is provided with a volume 36 for adjusting the output of the electromagnetic induction coils 12 and 13. The volume 36 needs to be readjusted at the time of aftercare or at the time of repair. Therefore, in the present embodiment, working through holes 37 and 38 are formed in the microcomputer board cover 28 and the nameplate 35 corresponding to the front of the volume 36 so that the operation of adjusting the volume 36 can be performed from the outside. Then, the working through hole 38 formed in the nameplate 35 is covered with an affixing seal 39 displaying a trademark or the like. In this way, when the volume 36 is readjusted, it is only necessary to peel off the sticker 39 without removing the nameplate 35, and the readjustment work becomes easy.

Further, a shoulder heater 43 for heating an inner lid 63 to be described later by heat conduction is attached to a shoulder portion 5b of the outer case 5 via a shoulder ring 44.
The lower end of the shoulder 5b is in contact with the tip of a flange 40 formed integrally with the upper end of the inner case 6, and the lower end of a hanging wall 41 extending from the inner peripheral edge of the shoulder 5b is connected to the flange. It is to be engaged with a step portion 42 formed on the inner peripheral edge of the portion 40. That is, the shoulder 5b and the flange 4
An annular space portion 45 is formed between the space portion 45 and the zero.

The shoulder ring 44 is attached by forcibly fitting locking pieces 46, 46 vertically provided from appropriate locations on the shoulder ring 44 into engagement holes 47, 47 formed in the shoulder 5b. Hanging wall 4 suspended from the inner peripheral edge
The lower end of 8 is engaged with the step portion 42. The hanging wall 41 of the shoulder 5b and the hanging wall 4 of the shoulder ring 44
Drainage outlets 49 and 50 are formed at the lower end of the drain 8. In this way, when water is accidentally applied to the shoulder 5b, the water enters through the engagement holes 47, 47, but is discharged to the inside of the inner case 6 through the drain holes 49, 50. Therefore, it is possible to prevent water from entering the rice cooker main body 1 and causing a failure of electric components and the like disposed therein.

On the other hand, the lid 2 has a hollow insulation 53 having a hollow portion 53 between an upper lid plate 51 made of synthetic resin (for example, polypropylene) and a lower lid plate 52 made of synthetic resin (for example, polypropylene). The rice cooker main body 1 (specifically, is attached to a hinge receiver 54 formed integrally with the outer case shoulder 5b via a hinge pin 55 so as to be detachable and openable. Reference numeral 56 denotes a spring for urging the lid 2 in the opening direction, and the spring 56 is assembled from inside the outer case 5. Reference numeral 57 denotes a spring for urging the lid 2 in the closing direction. It is a brake spring that reduces the urging force.

The upper cover plate 51 is, as shown in FIG.
Gas injection molding is performed to reduce the weight, and has hollow portions 70 and 71 formed by gas injection molding.

A cylindrical portion 58 is integrally formed on the lower surface of the central portion of the upper lid plate 51, while a cylindrical portion inserted into the cylindrical portion 58 is formed on the upper surface of the central portion of the lower cover plate 52. 5
9 are integrally erected, and the upper cover plate 5 is connected to the two cylindrical portions 58 and 59 via a helicoid 60.
1 and the lower lid plate 52 are detachably connected. Reference numeral 72 denotes a seal packing provided on an outer peripheral portion of a lower end of the cylindrical portion 59 on the lower lid plate 52 side,
When the upper cover plate 51 and the lower cover plate 59 are connected, the lower end of the cylindrical portion 59 on the upper cover plate 51 side is pressed to keep airtight. In this way, when the lid 2 is washed, the lid 2 can be washed in a state where it is disassembled into the upper lid plate 51 and the lower lid 52, so that it is easy to discharge the intruded water and to keep the inside of the lid 2 constantly. It can be kept clean. In addition, as a connecting means of the upper cover plate 51 and the lower cover plate 52, a screw connection may be employed instead of the helicoid 60.

The inside of the cylindrical portions 58 and 59 is
A steam discharge passage 61 for discharging steam S generated during rice cooking is provided, and the steam S passing through the steam discharge passage 61 is an exhaust port formed in a portion of the upper cover plate 51 surrounded by the cylindrical portion 58. 62 to be discharged outside. A pressure regulating cylinder 64 fixed to an inner lid 63 that seals the opening of the inner pan 3 when the lid 2 is closed is attached to and detached from the lower edge of the cylindrical portion 59 on the lower lid plate 52 side. It is freely inserted. That is, the inner lid 63 is detachable from the lid 2 via the pressure adjusting cylinder 64. The outer peripheral edge of the inner pan 3 is provided with the shoulder heater 4 described above when the lid 2 is closed.
3, the inner lid 3 is heated by the heat transfer from the shoulder heater 43, and the dew is prevented.
Reference numeral 65 denotes a steam port formed in the inner lid 63, and 66 denotes an inner lid 6
A seal packing 73 for maintaining airtightness between the opening 3 and the opening edge of the inner pot 3 is a steam inlet formed in the pressure regulating cylinder 64.

The lower lid plate 52 has a smaller diameter than the upper lid plate 51, and a seal packing 67 for maintaining airtightness with the inner lid 63 is attached to an outer peripheral edge thereof. . On the upper surface of the seal packing 67, an annular ridge 67a having a shape slightly protruding above the outer peripheral edge of the lower lid plate 52 is integrally formed. The outer peripheral edge of the lower end cover plate 52 is airtightly held so as to bite the ridge 67 a of the seal packing 67 against a step portion 68 formed on the lower surface of the upper cover plate 51 at the time of coupling by the helicoid 60. It is to be abutted. That is, between the upper lid plate 51 and the lower lid plate 52,
The inner peripheral portion is kept airtight by a seal packing 72, and the outer peripheral portion has a ridge 67 of the seal packing 67.
Thus, a hermetically sealed hollow portion 53 which is kept airtight is formed.

In the lower cover plate 52, a pair of operating portions 69, 69 for catching fingers when removing the lower cover plate 52 are provided outside the cylindrical portion 59. In the operating portions 69, 69, a portion close to the cylindrical portion 59 has an arc shape having a small curvature so as to easily catch a finger, and a portion away from the cylindrical portion 59 has an arc shape having a large curvature. By doing so, the operation unit 69,
If the finger is scratched on the reference numeral 69, the lower cover plate 52 can be easily removed, and the disassembling operation becomes easy.

Second Embodiment (Corresponding to Claims 1 to 4) FIG. 5 shows an electric rice cooker according to a second embodiment of the present invention.

In this case, an upward recess 77 for arranging the cord reel 76 is formed on the front side of the rice cooker main body 1 (specifically, the bottom member 7) (that is, on the side opposite to the hinge in the rice cooker main body 1). ing. Therefore, the surplus space 78 for installing the heat sink 75 is formed behind the front upward concave portion 77. Further, in the case of the present embodiment, a downward guide piece 24a that guides the outflowing air A upward and covers the inside so that the inside cannot be seen from the air outlet 24 is provided above the inner edge of the air outlet 24. It is formed integrally with the outer case 5. With this configuration, the flow path of the rising air A from the air inlet 23 to the air outlet 24 is a shortened upward flow path of the rising air A from the air inlet 23 to the air outlet 24. And the cooling effect of the heat sink 75 is further improved. The other configuration and operation and effect are the same as those in the first embodiment, and the description is omitted.

[0038]

According to the invention of the present application (the invention of claim 1),
An electric rice cooker using an electromagnetic induction coil as a heating means for the inner pan, comprising a rice cooker main body configured to accommodate an inner pan therein, wherein an air inlet is formed at the bottom of the rice cooker main body. On the other hand, an air outlet is formed in an upper part of the rice cooker main body, and a heat sink having electronic components attached thereto is provided near the air inlet in a flow path of air flowing from the air inlet toward the air outlet. Installed facing, air flowing from the air inlet, naturally rises toward the air outlet formed in the upper part of the rice cooker body, from the heat sink installed facing the air inlet in the process of By taking heat and cooling electronic components, electronic components can be cooled by natural airflow without using a cooling fan as in the past, reducing the number of components and It is possible to Sutodaun, cooling fan operation noise during cooking (i.e., rotation noise)
There is an excellent effect that no longer occurs.

According to a second aspect of the present invention, the rice cooker body has an inner case in which the inner pot is stored and an outer case forming an outer body. When the space formed between the inner case and the outer case is used as the air flow path, the electronic component can be cooled by effectively utilizing the space formed between the inner case and the outer case.

According to a third aspect of the present invention, a handle receiver for receiving a handle for carrying the electric rice cooker is provided at an upper portion of the rice cooker main body, and the air outlet is provided near a position below the handle receiver. When forming
The handle receiver located above the air outlet functions as an eaves for water or oneva flowing down from above, and it is possible to prevent water or oneva from entering the rice cooker main body from the air outlet.

As in the fourth aspect of the present invention, a cord reel for winding a power cord is provided at the bottom of the rice cooker main body, the heat sink is provided at the space, and the code reel is provided at the space. If the air inlet is formed in a surplus space formed by the above and the air inlet is formed at a position below the surplus space, the surplus space formed by installing a code reel in a space portion in the rice cooker main body is effective. Therefore, it is not necessary to form a special space for installing the heat sink in the space inside the rice cooker main body, and the size of the rice cooker main body can be reduced.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an electric rice cooker according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a plan view of a coil die in the electric rice cooker according to the first embodiment of the present invention.

FIG. 4 is an enlarged front view of a handle receiving portion of the electric rice cooker according to the first embodiment of the present invention.

FIG. 5 is a longitudinal sectional view of an electric rice cooker according to a second embodiment of the present invention.

[Explanation of symbols]

1 is a rice cooker body, 2 is a lid, 3 is an inner pot, 4 is a space, 1
2, 13 are electromagnetic induction coils, 23 is an air inlet, 24 is an air outlet, 25 is a handle, 26 is a handle receiver, 74 is an electronic component, 75 is a heat sink, and A is air.

Claims (4)

[Claims] 1. An electric rice cooker comprising an rice cooker body configured to accommodate an inner pot therein, and an electromagnetic induction coil as heating means for the inner pot, wherein a bottom portion of the rice cooker body is provided. In the upper part of the rice cooker body, while forming an air inlet, an air outlet is formed,
An electric rice cooker, wherein a heat sink to which an electronic component is attached is installed in a flow path of air flowing from the air inlet to the air outlet so as to be in close proximity to the air inlet. 2. The rice cooker main body has an inner case in which the inner pot is housed and an outer case forming an exterior body, and a space formed between the inner case and the outer case. 2. The air flow path of claim 1, wherein
An electric rice cooker as described. 3. An upper part of the rice cooker main body is provided with a handle receiver for receiving a handle for carrying the electric rice cooker, and the air outlet is formed near a position below the handle receiver. The electric rice cooker according to any one of claims 1 and 2, wherein the electric rice cooker is characterized in that: 4. A cord reel for winding a power cord is provided at a bottom of the rice cooker main body,
The said heat sink was installed in the surplus space formed by the said code reel being provided in the said space part, and the said air inlet was formed in the lower position of the said surplus space, The said Claim 2 characterized by the above-mentioned. Claim 3
An electric rice cooker according to any one of the preceding claims.