JP2001078884A - Rice cooker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To heat rice and water inside a rice cooker without nonuniformity in temp. and also to inexpensively heat them by forming electrodes on at least the paired opposing surfaces of an inner pot, connecting an AC power source between the pair of electrodes and heating rice and water by means of energizing. SOLUTION: Power is supplied from a commercial power source to the AC power source 4, boosting is executed by the power source 4, a current is permitted to flow in rice and water 3 between the electrodes 2 of the rice cooker, rice and water 3 are heated by joule heat generated in the rice and water 3 and rice is cooked. The inner surface of the inner pot 1 is coated by an electric isolating object such as a ceramic, a voltage is impressed on a part between the electrodes 2 without any problem, the shape of the inner pot 1 is made to be nearly a rectangular solid box shape and the electrodes 2 are disposed to be adjacent to the side surface of the inner pot 1. The electrodes 2 are of each a flat plate and arranged mutually in parallel, a uniform electric field distribution is obtained in rice and water 3 between the electrodes 2 so that they are heated without nonuniformity in temp. to obtain delicious cooked rice. The AC power source 4 is constituted of a transformer but can be constituted of an inverter.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rice cooker for heating and cooking rice by passing an electric current through rice water.

[0002]

2. Description of the Related Art As shown in FIG. 6, a conventional rice cooker stores rice water 3 in an inner pot 1 and energizes a heating means 2 such as a heater to heat the inner pot 1 to cook rice. It is.

[0003]

However, the rice cooker of the above-mentioned conventional construction has a problem that the heating efficiency is not good because the rice pan 3 is heated after the inner pot 1 is heated by the heating means 2 once. Had.

[0004]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is to form electrodes on at least a pair of opposing surfaces of an inner pot, connect an AC power supply between the electrodes, and heat the rice water. It is made.

[0005]

According to the first aspect of the present invention, rice water generates heat evenly.

According to the second aspect of the present invention, the inner pot is made of an electrically insulating material such as ceramic, so that the rice water generates heat more uniformly at a lower cost.

[0007] According to the third aspect of the present invention, since the electrical insulator has low thermal conductivity, rice water, which has particularly high thermal efficiency, generates heat evenly.

According to the invention described in claim 4, induction heating can be performed.

According to the fifth aspect of the present invention, the cooking unevenness is reduced at lower cost as a whole.

[0010] According to the invention described in claim 6, it is possible to carry out a heating pattern according to the amount of cooked rice.

[0011] According to the invention described in claim 7, it is possible to detect the end of rice cooking.

[0012] According to the invention described in claim 8, rice can be stored for a longer time.

[0013]

(Embodiment 1) An embodiment of the present invention will be described below. FIG. 1 is a sectional view of the rice cooker of the present embodiment. A power is supplied from a commercial power supply (not shown) to the AC power supply 4, the voltage is increased by the AC power supply 4, and a current flows through the rice water 3 between the electrodes 2.
The rice water 3 is heated by the Joule heat generated in the rice water 3 and cooked. The inner pot has an inner surface covered with an insulator (not shown) so that a voltage can be applied between the electrodes 2 without any problem. The shape of the inner pot 1 is a substantially rectangular box, and the electrode 2 is provided near the side surface of the inner pot. Since the electrodes 2 are flat plates and are installed in parallel with each other, the rice water 3 between the electrodes 2 has a uniform electric field distribution, and the rice water generates heat without unevenness in temperature, so that the rice cooker can produce delicious rice. I have.

In this embodiment, the AC power supply 4 is composed of a transformer, but may be an inverter. In this case, the size and weight can be further reduced.

The electrodes may be attached to the inner pot by a method such as bonding to an inner pot or bending into a U-shape and hooking on the edge of the inner pot. It is possible.

In FIG. 1, the inner pot 1 may be made of an electrical insulator, in this embodiment, a ceramic. The effect is the same as above, but the insulation processing of the inner pot becomes unnecessary,
It can be implemented at lower cost. Further, a configuration in which the inner pot 1 is made of an electrical insulator and has low thermal conductivity is also conceivable.

In the conventional rice cooker, rice water is heated via the inner pot, so that the inner pot needs to have good heat conductivity in order to improve the rice cooking performance. Since the rice cooker directly heats the rice water, the inner pot has low heat conduction, so that it can be a rice cooker with high thermal efficiency without releasing heat.

(Embodiment 2) A configuration having a sectional view as shown in FIG. 2 is also conceivable. That is, the heating coil 6 is installed on at least one surface of the inner pan, in this embodiment, near the outer surface of the bottom surface, and the inverter 5 supplies a high-frequency current to the heating coil 6. In the above-described embodiment, particularly, the temperature of cooked rice near the bottom surface relatively decreases due to the influence of heat radiation from the bottom surface. This is heated by the high-frequency magnetic field from the heating coil 6 to heat the bottom surface of the inner pot, thereby compensating for the temperature drop and reducing uneven cooking as a whole.

(Embodiment 3) It is also conceivable to adopt a configuration having a sectional view as shown in FIG. That is, in addition to the second embodiment, a metal plate is placed in the inner pot 1 and the heating coil 6 is installed near the outer surface of the placed inner pot, and the heating coil 6 is connected to the inverter 5. Thus, a high-frequency current is supplied. This configuration eliminates the need for insulation processing of the inner pot, can be performed at lower cost, and can easily achieve the heating of the bottom surface of the inner pot to compensate for the temperature drop and reduce uneven cooking as a whole.

(Embodiment 4) It is also conceivable to adopt a configuration having a sectional view as shown in FIG. That is, in addition to the first embodiment, the current detecting means 8 is provided between the AC power supply 4 and the electrode 2.
Is provided. In this embodiment, the current detecting means 8 uses a current transformer. The impedance of rice water between the electrodes 2 changes according to the amount of rice water, that is, the amount of cooked rice. When the amount of cooked rice is large, the impedance of the rice water decreases, and when the voltage from the AC power supply 4 is kept constant, the current flowing between the electrodes increases, and the output of the current detecting means also increases.

Thus, by inputting the output of the current detecting means to the rice cooking amount determining means (not shown), the rice cooking amount can be determined. As the rice cooking amount determination means, for example, a microcomputer can be used. By determining the amount of cooked rice, it is possible to implement a heating pattern according to the amount of cooked rice.

Also, a configuration having the same sectional view as shown in FIG. 4 may be employed. That is, the output of the current detection means 8 is input to the rice cooking completion determination means (not shown). As the rice cooking progresses, the water in the rice water decreases and becomes rice, so that the impedance between the electrodes increases. Therefore, when the current between the electrodes 2 becomes lower than a certain value, it can be determined that the rice water has become rice and cooking is to be completed. By judging that the rice cooking has been completed, the user can be notified of the completion of the rice cooking or use the power supply by ending the energization. The rice cooking completion determination means can be easily implemented by a comparator or a microcomputer.

(Embodiment 5) A configuration having a sectional view as shown in FIG. 5 is also conceivable. That is, a pulse voltage generating means is provided between the electrodes 2 in addition to the first embodiment. After cooking rice to convert rice water into rice as in the first embodiment, the pulse generator 9 is driven to generate a high-voltage pulse between the electrodes 2 and a pulse current is applied to the rice to produce rice. It destroys cell membranes such as bacteria adhering to, so that it can be sterilized. Therefore, rice can be stored longer.

[0024]

As described above, according to the first aspect of the present invention, a rice cooker capable of producing delicious cooked rice, in which rice water generates heat without uneven temperature.

According to the second aspect of the present invention,
By using an electrically insulating material such as ceramic for the inner pot, a rice cooker capable of producing delicious cooked rice at a lower cost can be realized, with rice water generating heat evenly.

According to the third aspect of the present invention,
By making the electrical insulator have low thermal conductivity, rice cooker which can produce delicious cooked rice by producing rice with high thermal efficiency without uneven temperature.

According to the fourth aspect of the present invention,
By providing a heating coil near at least one outer surface of the inner pot and performing induction heating, a rice cooker in which uneven cooking is reduced as a whole is realized.

According to the invention described in claim 5,
By placing a metal plate in the inner pan and installing a heating coil near the outer surface of the inner pan adjacent to the metal plate and performing induction heating, a rice cooker that is less expensive and less cooked as a whole is realized. is there.

According to the invention described in claim 6,
By providing a current detection means for detecting a current flowing between the electrodes, and a rice-cooking amount determination means for determining a rice-cooking amount based on the detection output of the current detection means, a heating pattern corresponding to the rice-cooking amount can be implemented. A rice cooker that is possible is realized.

According to the seventh aspect of the present invention,
By providing current detection means for detecting the current flowing between the electrodes, and rice cooking completion determination means for determining that rice cooking has been completed when the detection output of the current detection means is equal to or less than a certain value, the end of rice cooking can be notified. , A rice cooker that can be used, for example, by stopping power supply.

According to the eighth aspect of the present invention,
By providing a pulse voltage generating means for applying a pulse voltage of 1 kV or more between the electrodes, a rice cooker capable of storing rice for a longer time is realized.

[Brief description of the drawings]

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

FIG. 2 is a sectional view of a rice cooker according to a second embodiment of the present invention.

FIG. 3 is a sectional view of a rice cooker according to a third embodiment of the present invention.

FIG. 4 is a sectional view of a rice cooker according to a fourth embodiment of the present invention.

FIG. 5 is a sectional view of a rice cooker according to a fifth embodiment of the present invention.

FIG. 6 is a sectional view of a conventional rice cooker.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Inner pot 2 Electrode 3 Rice water 4 AC power supply 5 Inverter 6 Heating coil 7 Metal plate 8 Current detection means 9 Pulse voltage generation means

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) A47J 36/04 A47J 36/04 (72) Inventor Hideki Omori 1006 Odakadoma, Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. In-house F term (reference) 4B055 AA02 AA09 BA22 CA09 CA90 CC01 CC04 CC10 DA02 DA05 DB01 DB14

Claims (8)

[Claims] 1. A rice cooker wherein electrodes are formed on at least a pair of opposing surfaces of an inner pot, and an AC power supply is connected between the electrodes to heat and heat rice water. 2. The rice cooker according to claim 1, wherein the inner pot is made of an electrical insulator such as ceramic. 3. The rice cooker according to claim 2, wherein the electrical insulator has low thermal conductivity. 4. The rice cooker according to claim 1, wherein the inner pot is induction-heated. 5. The rice cooker according to claim 2, wherein the metal plate is placed in an inner pot, and a heating coil is installed near an outer surface of the inner pot adjacent to the metal plate to perform induction heating. 6. The method according to claim 1, further comprising a current detecting means for detecting a current flowing between the electrodes, and a rice cooking amount determining means for determining a rice cooking amount based on a magnitude of a detection output of the current detecting means. 6. The rice cooker according to any one of 5 above. 7. A rice cooking end determining means for detecting a current flowing between the electrodes, and a rice cooking end determining means for determining that the rice cooking is completed when a detection output of the current detecting means is less than a predetermined value. The rice cooker according to any one of claims 1 to 6. 8. The rice cooker according to claim 1, further comprising a pulse voltage generating means for applying a pulse voltage of 1 kV or more between the electrodes.