JP3159018B2 - Electric rice cooker - Google Patents

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 used in ordinary households.

[0002]

2. Description of the Related Art In recent years, electric rice cookers utilizing electromagnetic induction heating have been proposed. In FIG. 4, reference numeral 1 denotes a cylindrical body having an open upper surface, in which a coil base 2 serving as a storage portion for an inner pan 3 is disposed, and the coil base 2 is made of a nonmetallic material and has a bottom. It is formed in a cylindrical shape.

An induction coil 4 is disposed outside the coil base 2, and the induction coil 4 has tightly wound innermost and outermost turns. Further, the induction coil 4 is supported by a ferrite table 5 formed of a heat-resistant resin material on the lower part of the outer periphery of the coil base 2 so that the distance to the outer peripheral surface of the inner pot 3 is constant. A ferrite 6 is adhered to the ferrite base 5.

[0004]

However, in the configuration of the electric rice cooker, the weight of the induction coil 4 is large,
As a result, the weight of the electric rice cooker has increased, the usability has been poor, and resources have been wasted. Also, if the average distance between the inner pot 3 and the induction coil 4 is reduced, the rice cooking performance is improved,
For that purpose, for example, it is necessary to reduce the thickness of the coil base 2 or to reduce the gap between the inner pot 3 and the coil base 2, and in such a case, the strength of the coil base 2 decreases in the former, and in the latter, Since the amount of heat received from the inner pot 3 of the coil base 2 increases, it is necessary to improve the heat resistance by making the material of the coil base 2 a heat-resistant ceramic. Therefore, it is not easy to make the average distance between the inner pot 3 and the induction coil 4 close to each other, and the average distance between the inner pot 3 and the induction coil 4 cannot be reduced.

[0005] In view of the above circumstances, an object of the present invention is to provide an electric rice cooker which is lightweight and easy to use, improves rice cooking performance, and realizes resource saving.

[0006]

Means of the present invention to solve the above problems SUMMARY OF THE INVENTION becomes a body, an inner pot which is freely housed removably in the body, the bottom side portion of the inner bowl and encirclement A coil base and a bottom portion of the inner pan for induction heating the inner pan.
And an induction coil arranged on the bottom side surface portion , wherein the induction coil is configured by spirally winding a collective wire obtained by twisting a plurality of strands, and the collective wire is formed by the inner pot and an induction coil. In order to reduce the average distance of the coil, the winding width is made larger than the winding thickness.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 is to reduce the average distance between the inner pot and the induction coil by increasing the winding width of the collecting wire constituting the induction coil to a value greater than the winding thickness. It is possible to provide an electric rice cooker which can be reduced in thickness by the winding width-winding thickness of the wire, is lightweight, easy to use, and saves resources.

According to the second aspect of the present invention, the winding thickness of the induction coil is reduced by setting the ratio between the winding thickness and the winding width of the collective wire constituting the induction coil to be about 1: 1.3 to 3.0. Since the average distance between the induction coil and the inner pot is determined by the sum of the spatial distance between the inner pot and the induction coil and half the thickness of the induction coil, the distance between the inner pot and the induction coil is reduced to improve rice cooking performance. An electric rice cooker can be provided.

According to the third aspect of the present invention, the distance from the surface to the center of the conductor is reduced by setting the diameter of the conductor of the wire to 0.4 mm or less. Generally, a skin effect is known in which high-frequency current flows intensively on the surface layer of a conductor. By providing a predetermined surface area by reducing the diameter of the wire conductor portion and increasing the number of wires by this skin effect, an electric rice cooker is provided which suppresses self-heating of the induction coil and improves thermal efficiency and reliability. can do.

According to a fourth aspect of the present invention, the product of the diameter (in mm) of the conductor portion of the strand, the number of strands to be assembled, and the number of twists per 30 cm is substantially 50 or less.
Even if the cross-sectional shape of the collecting wire is easily deformed, and therefore, even if the winding thickness and the winding width ratio of the collecting wire are largely shifted, the electric rice cooker can be easily formed along the shape, so that an electric rice cooker with improved workability can be provided.

An embodiment of the present invention will be described below with reference to the drawings. (Embodiment) In FIG. 1, reference numeral 10 denotes a substantially cylindrical body having an open upper surface, reference numeral 11 denotes a coil base formed of a nonmetallic material into a bottomed cylindrical shape, and reference numeral 12 denotes an inner pot which is detachably mounted in the body 10. It is arranged. An induction coil 13 is provided outside the coil base 11. Further, the induction coil 13 is supported on a lower part of the outer periphery of the coil base 11 by a ferrite table 14 formed of a heat-resistant resin material so that the distance to the outer peripheral surface of the inner pot 12 is constant. A ferrite 15 is fixed to the ferrite table 14 to prevent the magnetic flux generated from the induction coil 13 from leaking downward. Reference numeral 15 denotes a circuit board for supplying a current for generating an alternating magnetic field to the induction coil 13, and reference numeral 16 denotes a synthetic resin outer lid.

In FIG. 2 and FIG. 3, reference numeral 17 denotes an insulating layer 17b and a fusion layer 17c so as to cover the entire circumference of a conductor 17a having a diameter of 0.3 mm. Reference numeral 18 denotes a collective wire, which is formed by bundling 34 strands of wire 17 and fitting them together three times within 30 cm. The assembly coil 18 is spirally wound to form the induction coil 13. Further, the winding width of the collecting wire 18 is W, the winding thickness is t, and the spatial distance from the inner pot 12 is d. In the present embodiment, the winding width W is 3 mm, and the winding thickness t is
Is 1.8 mm, and the spatial distance d is 5.5 mm. As described above, the collective wire 1 forming the induction coil 13
By making the winding width W of No. 8 larger than the winding thickness t, as shown in (Table 1), it is possible to reduce the thickness of the collecting wire 18 by (the winding width W-the winding thickness t), and it is lightweight and easy to use. Moreover, an electric rice cooker that saves resources can be provided.

[0013]

[Table 1]

The average distance between the induction coil 13 and the inner pot 12 is determined by the sum of the spatial distance d between the inner pot 12 and the induction coil 13 and 1/2 of the winding thickness t of the collecting wire. 1
The ratio of the winding thickness to the winding width of the collecting wire 18 constituting
Considering the weight of the coil 8 and the temperature of the induction coil at the time of use, for example, by setting the ratio to about 1: 1.3 to 3.0,
8 becomes thin, the inner pot 12 and the induction coil 13
Rice cooking performance can be improved by reducing the distance of the rice. In addition, since the rice cooking performance largely depends on the number of turns and the winding width of the induction coil 13, it matches the optimum value of rice cooking.

The diameter of the conductor portion of the wire 17 is set to 0.4
mm or less, the distance from the surface of the conductor 17a to the center is reduced, but a skin effect is generally known in which high-frequency current flows intensively on the surface layer of the conductor. By reducing the diameter of 17a and increasing the number of strands 17 to obtain a predetermined surface area, it is possible to provide an electric rice cooker in which self-heating of the induction coil is suppressed and thermal efficiency and reliability are improved.

Further, the diameter (in mm) of the conductor portion 17a of the wire 17, the number of wires 17 to be assembled, and 30 cm
By setting the product of the number of twists per round to approximately 50 or less, the cross-sectional shape of the collecting wire 18 is easily deformed, and the shape of the collecting wire 18 conforms to the shape even if the ratio between the winding thickness t and the winding width w is largely shifted. This facilitates the processability.

[0017]

As described above, according to the first aspect of the present invention, in order to reduce the average distance between the inner pot and the induction coil, the winding width of the collecting wire forming the induction coil is made larger than the winding thickness. This makes it possible to provide an electric rice cooker that is lightweight, easy to use, and resource saving.

Further, according to the second aspect of the present invention, the winding thickness and the winding width ratio of the collective wire forming the induction coil are set to approximately 1: 1.3.
By setting it to about 3.0, it is possible to provide an electric rice cooker in which the distance between the inner pot and the induction coil is reduced and the rice cooking performance is improved.

According to the third aspect of the present invention, the electric rice cooker in which the self-heating of the induction coil is suppressed and the thermal efficiency and reliability are improved by setting the diameter of the conductor portion of the wire to approximately 0.4 mm or less. Vessel can be provided.

Further, according to the fourth aspect of the present invention, the product of the diameter (in mm) of the conductor portion of the wire, the number of wires to be assembled, and the number of twists per 30 cm is approximately 50 or less. Thereby, an electric rice cooker with improved workability can be provided.

[Brief description of the drawings]

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

FIG. 2 is a cross-sectional view of a wire of the electric rice cooker.

FIG. 3 is a sectional view showing the vicinity of an inner pot of the electric rice cooker.

FIG. 4 is a cutaway sectional view of a conventional electric rice cooker.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Body 11 Coil base 12 Inner pan 13 Induction coil 17 Element wire 17a Conductor 17b Insulation layer 18 Assembly wire

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Masafumi Kubo 1006 Kazuma Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. (72) Inventor Seiichi Uemoto 1006 Kadoma Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. (72) Inventor Shoji Shimotani 1006 Kadoma Kadoma, Kadoma City Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. (72) Inventor Toshihiro Fujita 1006 Kazuma Kadoma, Kadoma City, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. (72) Inventor Atsushi 1006 Kadoma Kadoma, Kadoma City, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. 1006 Kazuma, Kamon, Fumonma-shi Matsushita Electric Industrial Co., Ltd. (56) Reference JP-A-6-261827 (JP, A) JP-A 61-240586 (JP A) Japanese Unexamined Patent Publication No. Hei 4-337606 (JP, A) Japanese Utility Model Application No. Sho 61-57490 (JP, U) Japanese Utility Model Application No. 54-31252 (JP, U) Japanese Utility Model Application No. Sho 55-44555 (JP, U) (58) Survey Field (Int.Cl. ⁷ , DB name) A47J 27/00

Claims (4)

(57) [Claims] 1. A body with an inner pot which is detachably accommodated in the body, and a coil base bottom side portion of the inner bowl formed by encirclement, inner bowl bottom portion及 for induction heating the inner bowl
And an induction coil arranged on the bottom side surface portion , wherein the induction coil is configured by spirally winding a collective wire obtained by twisting a plurality of strands, and the collective wire is formed by the inner pot and an induction coil. An electric rice cooker whose winding width is larger than the winding thickness to reduce the average distance of the coil. 2. The electric rice cooker according to claim 1, wherein a ratio of a winding width to a winding thickness of the collecting wire is approximately 1.3 to 3.0. 3. The strand has a diameter of a conductor portion of about 0.4.
The electric rice cooker according to claim 1 or 2, wherein the thickness is not more than mm. 4. The product according to claim 1, wherein the product of the diameter (in mm) of the conductor of the strand, the number of strands to be assembled, and the number of twists per 30 cm is approximately 50 or less. An electric rice cooker according to claim 1.