JP2010063933A - Electric rice cooker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To cook delicious rice by utilizing the merit of an inner pot made of ceramic, and to keep it delicious for a long time by effectively preventing the degradation of the rice even after it is cooked. <P>SOLUTION: The inner pot is made of ceramic, an induction heating means is provided on the outer side of the bottom part of a protective frame and a curved part from the bottom part to a peripheral side surface, and a heating element such as a metal film is formed at two parts roughly facing the induction heating means in the inner pot. Between the respective heating elements at the bottom part of the inner pot, the foot part of a prescribed thickness for keeping a distance between the heating element and the heating means almost without variance by abutting on the bottom part of a protective frame is formed. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an induction heating type electric rice cooker, and more particularly to a technique for effectively using a ceramic product as an inner pot for cooking rice.

  In a conventional induction heating type electric rice cooker, an inner pot for rice cooking is detachably stored in the rice cooker body, and a protective frame made of a synthetic resin for waterproofing is provided along the shape of the inner pot. An induction coil is provided on the back side of the protective frame as induction heating means for induction heating the inner pot.

  Moreover, the metal thing is conventionally used as the inner pot for rice cooking. That is, for example, a multi-layer structure in which the outer wall of the inner pan is made of stainless steel, the inner wall is made of aluminum, and the inner wall of the aluminum inner wall is coated with fluorine is used (see, for example, Patent Document 1).

  And at the time of cooking rice, energize the induction coil in a state where a predetermined gap is secured between the inner pot and the protective frame by hooking the flange formed on the upper part of the inner pot to the upper opening end of the protective frame. The inner pot is heated by induction.

  By the way, because the inner pan made of metal has the property that it is easy to heat and cool easily, the rice is heated quickly during cooking, so the taste when cooked is still insufficient. is there. Moreover, since it is easy to cool after cooking rice, the energy which uses rice for heat insulation becomes large, and it is not preferable when aiming at an energy-saving measure.

  Therefore, in order to make up for the drawbacks of such a metal inner pot, it is conceivable to use a ceramic inner pot. That is, since the thing made from ceramics has a large heat capacity compared with the thing made from metal, the temperature increase rate at the time of rice cooking is comparatively gentle, and since heat storage property is good, it can cook cooked rice deliciously. Moreover, when there is unprocessed rice in the inner pot, it is possible to reheat the entire inner pot with a microwave oven, and there is an advantage that a warm state can be kept long after the reheating because heat storage is good.

JP 2000-70145 A

  However, simply replacing the conventional metal inner pot with a ceramic inner pot causes the following various problems.

  (1) When the inner pot is made of ceramics, the finished dimensions of the entire inner pot are likely to vary depending on the moisture content during firing and the firing conditions, and the dimensional accuracy is poor compared to that made of metal. For this reason, as in the case of a metal inner pot, when the flange formed on the upper part of the inner pot is hooked on the upper opening end of the protective frame, the distance between the inner pot and the induction coil varies from product to product. End up. As described above, when the distance between the inner pot and the induction coil varies for each product, the resonance condition between the two also fluctuates, and the rice cooking performance quality deteriorates.

  (2) In order to avoid the inconvenience of (1) above, another problem occurs when the bottom of the inner pot is placed directly on the protective frame. In other words, since ceramics are non-conductive, they cannot be induction heated as they are. For this reason, a heating element is formed by applying and baking silver paste or the like at a location facing the induction coil of the inner pot, but even in this case, since the thermal conductivity of the ceramic itself is poor, the heating element Only the formation part of the is likely to become high temperature. Therefore, when the bottom part of the inner pot is placed directly on the protective frame, when the protective frame is made of a synthetic resin, there arises a problem that it cannot withstand the temperature and melts.

  (3) Also, since the ceramics have poor thermal conductivity, the temperature gradient between the heating element formation and the metal coating non-formation is large, and temperature unevenness is likely to occur, and the cooked state of cooked rice may deteriorate. There is.

  (4) As mentioned above, when the inner pot is made of ceramic, there is an advantage that the cooked rice can be cooked deliciously because of its good heat storage, while the cooked rice is kept at a high temperature. Will become longer. For this reason, the cooked rice is likely to deteriorate. That is, when cooked cooked rice is exposed to a high temperature (for example, 80 to 85 ° C.) for a long time, it undergoes a chemical reaction such as oxidation of fatty acids contained in the cooked rice during that time and deteriorates, and deterioration such as turning brown. It is easy to cause.

  The present invention solves the problems as pointed out in the above (1) to (4), can cook delicious cooked rice by taking advantage of the inner pot made of ceramics, and deteriorates cooked rice even after cooking. An object of the present invention is to provide an electric rice cooker that can effectively prevent the above-described problem and keep the taste delicious for a long time.

  In order to achieve the above-mentioned object, the present invention includes a rice cooker body in which an inner pot is detachably stored, and a protective frame is provided outside the inner pot along the shape of the inner pot. In an electric rice cooker in which induction heating means for induction heating the inner pot is provided outside the protective frame, the following configuration is adopted.

  That is, in the electric rice cooker according to the present invention, the inner pot is made of porcelain, and the induction heating means is provided on the outside of the bottom part of the protective frame and the curved part from the bottom part toward the peripheral side surface, A heating element such as a metal coating is formed at two locations substantially opposite to the heating means, and the heating element and the heating means are in contact with the bottom of the protective frame between the heating elements at the bottom of the inner pot. One feature is that a leg portion having a predetermined thickness is formed so as to keep the distance between and a substantially uniform distance.

  In the electric rice cooker according to the present invention, the inner pot is made of porcelain, and the induction heating means is attached to the outside of the bottom part of the protective frame and the curved part from the bottom part toward the peripheral side surface. The heating element such as a metal film is formed at two locations substantially opposite to the induction heating means, and between the heating elements at the bottom of the inner pot, the bottom of the protective frame is in contact with the heating element. Another feature is that a leg portion having a predetermined thickness is formed to keep the distance from the heating means substantially uniform.

  According to the present invention, since the inner pot made of ceramic is used, the cooked rice can be cooked deliciously with a relatively gentle heating rate during cooking. In addition, even if the finished size of the entire inner pot varies from product to product, the change in the thickness of the legs formed on the bottom of the inner pot is extremely small. Variation in the distance between the body and the induction heating means attached to the outside of the bottom of the protective frame is reduced. For this reason, rice cooking performance quality is increased stably. In addition, by providing a leg at the bottom of the inner pot, there is no gap between the heating element formed on the inner pot and the protective frame, so that they do not directly contact each other. However, even when the temperature is locally high, there is no inconvenience that the protective frame made of synthetic resin melts. Furthermore, since it is not necessary to form a flange for hooking on the upper opening end of the protective frame at the upper end portion of the metal inner pot, the flange portion is damaged due to insufficient strength. There is no fear.

In the electric rice cooker in Embodiment 1 of this invention, it is a longitudinal cross-sectional view which shows the form in the case of using the inner pot 6 made from ceramics. In the electric rice cooker of Embodiment 1 of this invention, it is a longitudinal cross-sectional view which shows the form in the case of using metal inner pots 6. FIG. It is a partially cutaway side view of the electric rice cooker in Embodiment 2 of this invention. It is a partially cutaway side view which shows the modification of the electric rice cooker in Embodiment 2 of this invention. It is a partially cutaway side view of the electric rice cooker in Embodiment 3 of this invention. It is a partially cutaway side view of the electric rice cooker in Embodiment 4 of this invention.

[Embodiment 1]
1 is a longitudinal sectional view of an electric rice cooker according to Embodiment 1 of the present invention.

  The electric rice cooker according to the first embodiment includes a rice cooker body 1 and a lid body 2 that opens and closes an upper opening of the rice cooker body 1, and the lid body 2 is attached to the rice cooker body 1 via a hinge unit 3. It is supported so that it can be opened and closed.

  The rice cooker body 1 has an outer case 5 made of a synthetic resin-made integrally molded product, and an inner pot 6 made of ceramics is detachably stored in the outer case 5. A protective frame 7 along the shape of the inner pot 6 is provided on the outside of the inner pot 6. The protective frame 7 is made of a heat-resistant synthetic resin such as polyethylene terephthalate (hereinafter abbreviated as PET), and a sensor insertion hole 7a for facing the temperature sensor 9 is formed at the center of the bottom. Yes. The upper end of the protective frame 7 is integrally coupled to the upper end of the outer case 5 via the shoulder member 8. A space 10 is formed inside the outer case 5, the protective frame 7, and the shoulder member 8. In addition, said shoulder member 8 becomes a latching member by which the flange formed in the upper end part of the said inner pot 6 is latched corresponding to the case where the inner pot 6 is metal.

  Outside the protective frame 7, induction coils 11 and 12 are provided as induction heating means for induction heating the inner pot 6. These induction coils 11 and 12 are provided concentrically around the center of the bottom of the protective frame 7 at each position of the bottom of the protective frame 7 and the curved portion extending from the bottom to the peripheral side. A synthetic resin coil retainer 13 is provided outside the induction coils 11 and 12, and the coil retainer 13 is attached to the protective frame 7 with screws or the like, so that each induction coil 11 and 12 is It is positioned and fixed at the predetermined position. A warming cord heater 14 is provided on the outer peripheral side of the upper portion of the protective frame 7. Further, a ferrite core 15 for confining the magnetic field is provided outside the coil retainer 13.

  On the other hand, the aforementioned inner pot 6 is made of ceramics such as baked ceramics or glass, and an annular leg 6 a that contacts the bottom of the protective frame 7 is formed on the bottom of the inner pot 6. . In addition, this leg part 6a is not restricted to an annular | circular shaped thing, It is also possible to form locally or to form radially. And this leg part 6a is provided in the location located between the induction coil 11 by the side of the bottom part of the protective frame 7, and the induction coil 12 by the side of a curved part, and fixed between the protective frame 7 is fixed. The gap s1 is formed to have a predetermined thickness. In addition, the inner pot 6 is provided with a heating element (not shown) made of a metal film at a location facing the induction coils 11 and 12. The heating element in this case is formed, for example, by applying and baking a silver paste or the like. The leg portion 6a of the inner pot 6 has an uneven surface, so that it is difficult to form a heating element. However, the location where the leg portion 6a is formed deviates from the position facing any of the induction coils 11 and 12. Therefore, there is no effect on rice cooking performance. Accordingly, the portions facing the induction coils 11 and 12 have a flat surface, which is convenient because a heating element can be easily formed.

  Furthermore, the dome-shaped central portion 6b with which the temperature sensor 9 at the bottom of the inner pot 6 abuts is formed to be slightly thinner to the extent that the strength is not impaired compared to the other portions. In this way, by forming the central portion 6b of the inner pot 6 thinly, heat from the heating element is easily conducted to the thin central portion 6b, so that the detection accuracy of the temperature sensor 9 can be increased, The power supplied to the induction coils 11 and 12 can be appropriately controlled.

  In addition, 18 is an operation panel having a liquid crystal display unit, 19 is a microcomputer board on which a microcomputer is mounted, 20 is mounted with a power supply circuit having an inverter or the like for controlling energization of the induction coils 11 and 12. A power supply board 21 is a board cooling fan for cooling the boards 19 and 20. Reference numeral 24 denotes an aluminum inner lid constituting the lid 2, 25 denotes a cord heater provided on the upper portion of the inner lid 24, 26 denotes a steam discharge port, and 27 denotes a handle.

  Thus, since the electric rice cooker of this Embodiment 1 uses the thing made from ceramics as the inner pot 6 for rice cooking, since the temperature increase rate at the time of rice cooking is comparatively gentle, and heat storage property is good. Delicious rice can be cooked.

  Moreover, even if the finished dimensions of the entire inner pot 6 vary from product to product, the change in the thickness of the leg 6a formed on the bottom of the inner pot 6 is extremely small, so the gap between the inner pot 6 and the induction coils 11 and 12 is small. Variation in distance is reduced. For this reason, the resonance conditions by the heating element provided on the surface of the inner pan 6 and the induction coils 11 and 12 are stabilized, and the rice cooking performance quality is improved. Moreover, by providing the leg part 6a at the bottom of the inner pot 6, a gap s1 is formed between the portion of the heating element formed in the inner pot 6 and the protective frame 7, and both 6, 7 can be in direct contact with each other. Therefore, there is no inconvenience that the protective frame 7 made of synthetic resin melts even when the heating element is locally formed at a high temperature.

  Further, when the ceramic inner pot 6 is used, it is not necessary to form a flange for hooking on the upper part of the protective frame 7 at the upper end portion unlike the conventional metal inner pot 6, so that the flange portion There is no risk of damage due to insufficient strength.

  Moreover, in this Embodiment 1, it can replace with said ceramic inner pot 6 and can use the metal inner pot 28. FIG. That is, when using the metal inner pot 28, as shown in FIG. 2, as in the conventional case, a flange 28 a formed on the upper end portion of the shoulder member 8 provided at the upper opening end of the protective frame 7 is provided. Hang. In this way, by allowing the metal inner pot 28 to be hooked on the shoulder member 8, it can be used in exchange for the ceramic inner pot 6, and convenience is enhanced.

  In the first embodiment, a metal film such as silver paste is formed on the surface of the inner pot 6 to form a heating element. However, the present invention is not limited to this. For example, a copper foil or a stainless steel net (lass) is used. It is also possible to adopt a configuration in which a metal heating element such as) is previously embedded integrally in the inner pot 6. In this way, the embedded heating element serves as a reinforcing material for the inner pot 6, so that it is convenient to prevent cracking even when an impact is applied. As an embedding location in this case, in order to reinforce the whole inner pot 6, it is preferable to provide it from a peripheral side part to a bottom face.

[Embodiment 2]
FIG. 3 is a partially cutaway side view of an electric rice cooker according to Embodiment 2 of the present invention, and the same reference numerals are given to components corresponding to or corresponding to Embodiment 1 shown in FIG.

  A feature of the electric rice cooker according to the second embodiment is that a contact portion with the leg portion 6a of the ceramic inner pot 6 is constituted by a ceramic plate 31. That is, the plate 31 is an annular flat plate made of fired ceramics or glass, and a mounting hole 31a for the temperature sensor 9 is formed at the center thereof. And when the inner pot 6 is mounted, the leg part 6a contacts the upper surface of the plate 31. The other part of the protective frame 7 is made of a heat-resistant synthetic resin such as PET.

  In the case of the configuration of the second embodiment, the contact portion of the protective frame 7 with the leg portion 6a of the inner pot 6 is composed of the ceramic plate 31, so that it is protected by friction with the ceramic inner pot 6. The frame 7 is hardly damaged and can be used for a long time. Further, since the surface of the plate 31 is flat, the shape and dimensions are stable, and the variation in the distance between the bottom surface of the inner pot 6 and the induction coils 11 and 12 is further reduced. For this reason, the resonance conditions by the heating element provided on the surface of the inner pan 6 and the induction coils 11 and 12 are stabilized, and the rice cooking performance quality is improved. Moreover, even when the temperature of the inner pot 6 rises abnormally, the portion of the plate 31 with which the leg portion 6a abuts is made of ceramic and has low thermal conductivity. The adverse effect on the part can be reduced.

  Since other configurations and operational effects are the same as those in the first embodiment, detailed description thereof is omitted here.

  In addition, in FIG. 3, although the location of the bottom part contact | abutted with the leg part 6a of the inner pot 6 is comprised with the plate 31, instead, as shown in FIG. It is also possible to use a pot-shaped member 32 made of ceramic.

  In the case of this configuration, as in the case of the second embodiment, the contact portion with the leg portion 6a of the inner pot 6 is made of ceramic, so that it is difficult to be damaged and can be used for a long time. The joint portion between the member 32 and the protective frame 7 made of synthetic resin becomes a high position, the waterproof effect is enhanced, and the maintenance is facilitated. In addition, even when the temperature of the inner pot 6 rises abnormally, the portion facing the induction coils 11 and 12 is composed of the porcelain bowl-shaped member 32, and thus has an adverse effect on the protective frame 7 made of synthetic resin. There is an advantage that it can be further reduced.

[Embodiment 3]
FIG. 5 is a partially cutaway side view of an electric rice cooker according to Embodiment 3 of the present invention. Components corresponding to or corresponding to those of Embodiment 1 shown in FIG.

  The feature of the electric rice cooker of this Embodiment 3 is that the heater 33 for auxiliary heating, and this are utilized using the space part 10 surrounded by the outer case 5, the protective frame 7, and the shoulder member 8 of the rice cooker body 1. The fan 34 is provided to blow the air heated by the heater 33 to the back surface of the inner pot 6 through the opening 7 b formed in the protective frame 7.

  In the case of the configuration of the third embodiment, at the time of cooking rice, both the auxiliary heater 33 and the fan 34 are activated to send hot air toward the gap s1 between the inner pot 6 and the protective frame 7, thereby making the ceramics It is possible to heat the peripheral side portion of the inner pot 6 which is likely to be short of heat supply due to the poor thermal conductivity of the inner pot 6 made of metal. Thereby, generation | occurrence | production of temperature nonuniformity can be eliminated and uniform heating can be performed and rice cooking performance improves.

Immediately after cooking, the energization of the auxiliary heating heater 33 is stopped, and the same fan 34 is used to send cold air to the gap s1 between the inner pot 6 and the protective frame 7 to keep the inner pot 6 at a predetermined temperature. Can cool quickly to temperature. For this reason, the cooked cooked rice is not exposed to high temperatures for a long time, and deterioration of cooked rice can be prevented.

  Since other configurations and operational effects are the same as those in the first embodiment, detailed description thereof is omitted here.

[Embodiment 4]
FIG. 6 is a longitudinal sectional view of the electric rice cooker according to the fourth embodiment.

  Although the electric rice cooker of said Embodiment 1-3 is a direct heating system which induction-heats an inner pot with an induction coil, the electric rice cooker of this Embodiment 4 heats and boiles an inner pot. This is an indirect heating method in which heating is performed indirectly.

  That is, the electric rice cooker according to the fourth embodiment includes a rice cooker body 41 and a lid body 42 that opens and closes the upper opening of the rice cooker body 41, and the lid body 42 is connected to the rice cooker body 41 via the hinge 43. It is supported to open and close freely.

  The rice cooker main body 41 has an outer case 45 made of an integrally molded product made of synthetic resin, and an inner pot 46 is detachably housed inside the outer case 45, and on the outer side of the inner pot 46. Is provided with a heating container 47 along the shape of the inner pot 46. In this case, the inner pot 46 is made of ceramics such as ceramics, porcelain, or glass. The heating vessel 47 is made of a metal such as stainless steel, and a resistance heating type electric heater 48 is disposed at the bottom of the heating vessel 47.

  Moreover, the water storage tank 49 and the pump 50 are attached to the outer side of the peripheral side part of the outer case 5, and the water of the water storage tank 49 passes through the pump 50 and the check valve by starting the pump 50 during rice cooking. A predetermined amount of water is supplied to a gap s2 formed between the inner pan 6 and the heating container 47.

  In addition, 54 is a gasket for preventing steam leakage, 55 is a steam outlet provided in the lid 42, 56 is a pressure regulating valve, and 57 is an aluminum inner lid.

  In the case of the configuration of the fourth embodiment, the water injected into the gap s2 formed between the inner pot 6 and the heating container 47 is heated and boiled by the electric heater 48 to indirectly heat the inner pot 6. Since it is a heating system, uneven heating and scorch are less likely to occur compared to the direct heating system, and it can be cooked deliciously. Moreover, since heat can be uniformly transmitted to the inner pot 6 by the hot water accumulated in the gap s2, it is only necessary to provide a resistance heating type electric heater 48 at the bottom of the heating container 47, and an induction coil is used. Since it is not necessary, the cost required for the heating source can be reduced.

  In addition, after cooking the cooked rice, for example, the inner pot 46 can be cooled relatively quickly by injecting a smaller amount of water into the gap s2 between the inner pot 46 and the heating container 47 than the amount of water injected at the time of cooking. Therefore, the cooked cooked rice is not exposed to a high temperature for a long time, and the cooked rice can be prevented from deteriorating.

DESCRIPTION OF SYMBOLS 1 Rice cooker main body 2 Lid body 6 Inner pan 6a Leg part 6b Center part 7 Protection frame 8 Shoulder member (holding member)
9 Temperature sensor 11 Induction coil (Induction heating means)
12 Induction coil (Induction heating means)
31 Plate (ceramic material)
32 bowl-shaped member (ceramic member)
33 Auxiliary heater 34 Fan s1 Clearance

Claims (2)

In the rice cooker body, an inner pot is detachably stored, and a protective frame is provided outside the inner pot along the shape of the inner pot. The inner pot is guided outside the protective frame. In the electric rice cooker provided with induction heating means for heating,
The inner pot is made of porcelain, and the induction heating means is provided outside the bottom of the protective frame and the curved portion from the bottom to the circumferential side, and the inner pot has a metal coating at two locations substantially opposite the induction heating means. And a heating element such as a heating element is formed between the heating elements at the bottom of the inner pot so that the distance between the heating element and the heating means is kept almost uniform. An electric rice cooker characterized in that a thick leg is formed. In the rice cooker body, an inner pot is detachably stored, and a protective frame is provided outside the inner pot along the shape of the inner pot. The inner pot is guided outside the protective frame. In the electric rice cooker provided with induction heating means for heating,
The inner pot is made of porcelain, and the induction heating means is provided on the outside of the bottom part of the protective frame and the curved part from the bottom part toward the peripheral side surface, and the inner pot is provided at two locations substantially opposite to the induction heating means. A heating element such as a metal film is formed, and between the heating elements at the bottom of the inner pot, abuts against the bottom of the protective frame so as to keep the distance between the heating element and the heating means almost uniform. Another feature is that a leg portion having a predetermined thickness is formed.

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