JP2892565B2 - Electric 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 cooker (typically, a rice cooker) for heating an inner pot with a heating plate and heating and cooking an object to be cooked in the inner pot. This is related to temperature detection for performing

[0002]

2. Description of the Related Art As a rice cooker capable of cooking rice with uniform heating by uniform heating, a cooker in which an inner pot and a heater plate are formed in a hemispherical shape and the heat conduction between the outer periphery and the central portion is made uniform has been realized. No. 55-124216.

In Japanese Patent Publication No. 3-49245, a thermoswitch is removed from a central portion of a rice-cooking heater disposed on a bottom portion of an inner pot, and uniform heating is performed from the entire bottom surface of the inner pot so that there is no uneven cooking. A rice cooker that cooks rice is disclosed, and a temperature detection unit that detects the temperature of the side surface of the inner pot as an essential component thereof, and a rice cooking amount detection unit that detects a rice cooking amount based on the temperature detected by the temperature detection unit. Further, there is disclosed an electric power control unit for terminating the rice cooking when the temperature detecting unit detects a predetermined temperature according to the amount of cooked rice.

[0004]

In order to cook delicious rice, a uniform heating structure disclosed in the prior art is employed, and the amount of rice cooked is accurately detected to accurately cook rice according to the amount of rice cooked. It is important to control.

[0005] Therefore, an object of the present invention is to detect an accurate amount of cooked rice. Incidentally, the above-mentioned Japanese Utility Model Application
No. 16 discloses no technical idea for detecting the amount of cooked rice, and the means for detecting the amount of cooked rice disclosed in Japanese Patent Publication No. 3-49245 detects the amount of cooked rice based on the temperature of the inner pot side surface. Since the temperature rise is saturated at 100 ° C., the temperature rise width is small, and it is difficult to accurately detect the amount of cooked rice.

[0006]

Means for Solving the Problems An inner pan, a heating plate for heating the bottom and side portions of the inner pan, a temperature detecting element for detecting a temperature at an upper side of the heating plate, and a temperature detected by the temperature detecting element. And an amount detecting means for detecting an amount of the object to be cooked based on a temperature gradient at an upper portion of the heating plate side.

The upper side of the heating plate preferably has a portion corresponding to the water level line of the rated maximum capacity of the inner pot, but the position corresponding to the water level line is not limited as long as the position is suitable for detecting the amount.

The invention of claim 2 is an invention in which the essential parts of the essential components are the same as those of claim 1, wherein the removable inner pot and the heating for heating the bottom and sides of the inner pot are provided. A plate, a temperature detecting element for detecting a temperature at an upper side of the heating plate, and an abnormal state detecting means for detecting a no-load state or an unmounted state of the inner pot based on the temperature of the upper side of the heating plate detected by the temperature detecting element. And It is considered that the abnormal state detecting means detects a predetermined attained temperature or a predetermined temperature gradient.

[0009]

[Function] Since the heating plate is arranged to the bottom and side surfaces of the inner pan, uniform heating can be performed so as to wrap the food, and the temperature gradient (degree of temperature rise) at the upper part of the heating plate side detected by the temperature detection element is inside. Since the amount changes remarkably in accordance with the amount of the food stored in the pot, the amount can be easily detected and the accuracy can be increased.

[0010] The reason why the temperature rise at the upper portion of the heating plate changes remarkably in accordance with the amount of the food to be cooked is that the temperature rise is large (the saturation temperature is high) because of the temperature of the heating plate. This is because heat is taken away through the inner pot by the water level according to the amount.

When the amount of the object to be cooked is large, the temperature gradient is gentle, and when the amount of the object to be cooked is small, the temperature gradient becomes steep. Further, in a state where there is no load in the inner pot or an abnormal state where the inner pot is not mounted, the temperature gradient is steeper and the saturation temperature is higher, so that the abnormal state can be detected early.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A rice cooker which is a typical electric cooker will be described as an example. FIG. 1 is a vertical sectional view of a rice cooker according to the present invention. The rice cooker is roughly composed of a main body 1 and a lid 2. Reference numeral 3 denotes a substantially hemispherical inner pot removably housed in the main body 1 and has an inner surface treated with a fluororesin.
4 is a heating plate for heating the bottom surface and side peripheral surface of the inner pot 3,
It is formed so as to wrap the entire outer peripheral surface of the inner pot 3 with an aluminum casting having good thermal conductivity, and the heating sheath heater 5 is embedded therein.

Reference numeral 6 denotes a heat shield plate provided outside the heating plate 4 so as to surround the heating plate 4, and a heating plate 4 is provided on an upper side of the inner pot 3 corresponding to a water level line of the rated maximum rice cooking amount. A temperature detecting element 7 for detecting the temperature of the inner pan 3 is mounted in a state of being pressed against the heating plate 4, and a thermosensitive device 9 having a built-in temperature detecting element 8 for detecting the temperature of the inner pan 3 is mounted at the center of the bottom surface. .

Reference numeral 10 denotes a heat insulating heater provided on the outer surface of the heat shield plate 6, reference numeral 11 denotes a control circuit 12, which controls the entire rice cooker,
A control board incorporating the rice cooker relay 13 and the like, 14 is an outer case of the rice cooker, 15 is a bottom cover, and 16 is a code reel. 17, 18, 19, and 20 are upper lids that constitute the lid 2,
An inner lid, inner lid packing, and a lid heater for keeping warm.

The rice cooking operation of the electric rice cooker will be described with reference to a basic electric circuit diagram shown in FIG.

When rice washing and water are put into the inner pot 3 and rice cooking is started, the control circuit 12 drives the rice cooking relay 13 to energize the sheath heater 5 to heat the heating plate 4. The heat of the heating plate 4 is transmitted to the inner pot 3 to heat the water in the inner pot 3, and the preheating operation and the rice cooking operation are performed.

At the start of the rice cooking operation, the temperature detecting element 7 and the temperature detecting element 8 detect the temperature of the heating plate 4 and the temperature of the inner pot 3, and the calculating means (not shown) in the control circuit 12 operates the temperature per predetermined time. The amount of cooked rice is detected by calculating the rise, that is, the temperature gradient, and comparing it with a data table previously obtained by an experiment and stored in a storage means (not shown).

The detection of the amount of cooked rice is generally more accurate based on the temperature gradient of the heating plate 4 than the one obtained from the temperature gradient of the inner pot 3, but even under various conditions with both temperature gradients involved. By creating a data table so that it can be applied, it is possible to more accurately detect the amount of cooked rice.

The heating power control after boiling in the rice cooking operation is performed in accordance with the detected amount of cooked rice. The smaller the amount of cooked rice, the more the conduction rate of the sheathed heater 5 is suppressed, and the overheating of the heating plate 4 and the overflow. To prevent scorching.

When the water content evaporates and disappears and the temperature of the bottom surface of the inner pot 3 rises rapidly to 100 ° C. or more, the end of the rice cooking operation is detected by the heat sensing device 9 and the steaming operation is started. Then, when the steaming operation is completed, the energization control of the warming heater 10 and the warming lid heater 20 according to the amount of cooked rice is performed by the semiconductor switching elements 21 and 22, and the warming operation for keeping the temperature of the rice at about 74 ° C. is performed. .

The reason "the detection of the amount of cooked rice determined from the temperature gradient of the heating plate 4 is generally more accurate than the detection of the amount of cooked rice determined from the temperature gradient of the inner pan 3" is because the temperature rise of the heating plate 4 This is because the width is larger than the temperature rise width of the inner pot 3, and this is obvious from the temperature diagram shown in FIG.

When the amount of the object to be cooked is large, the temperature gradient is gentle, and when the amount of the object to be cooked is small, the temperature gradient becomes steep, and there is no load in the inner pot 3 or an abnormal state in which the inner pot 3 is not mounted. In this case, the temperature gradient becomes steeper and the saturation temperature becomes higher. Therefore, by storing a data table for detecting an abnormal state in the control circuit 12 in a storage means (not shown), the abnormal state can be detected early.

[0023]

According to the present invention, since the heating plate is disposed to the bottom and side surfaces of the inner pan, uniform heating can be performed so as to wrap the food, and the temperature gradient of the upper portion of the heating plate detected by the temperature detecting element can be obtained. (Temperature rise) changes remarkably according to the amount of the food stored in the inner pot, so that the amount can be easily detected and accurate detection can be performed.

As a result, when the present invention is applied to a rice cooker, it is possible to perform an optimal heating sequence according to the amount of cooked rice, and to cook delicious rice.

In addition, a state in which no load is present in the inner pot or an abnormal state in which the inner pot is not mounted can be detected at an early stage, which can contribute to improvement in safety and reliability.

[Brief description of the drawings]

FIG. 1 is a vertical sectional view of an electric rice cooker showing one embodiment of the present invention.

FIG. 2 is a basic electric circuit diagram of the electric rice cooker showing one embodiment of the present invention.

FIG. 3 is a temperature diagram of a heating plate and an inner pot for explanation of the present invention.

[Explanation of symbols]

 3 inner pot 4 heating plate 5 sheathed heater 6 heat shield plate 7 temperature detecting element (for heating plate) 8 temperature detecting element (for inner pot) 9 heat sensitive device 12 control circuit

──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Hideshi Nakagawa 22-22 Nagaikecho, Abeno-ku, Osaka-shi, Osaka Inside Sharp Corporation (56) References JP-A-4-272720 (JP, A) JP-A-56- 168722 (JP, A) JP-A-61-76116 (JP, A) JP-A-59-211415 (JP, A) JP-A-51-12563 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) A47J 27/00

Claims (2)

(57) [Claims] 1. An inner pot, a heating plate for heating a bottom portion and a side portion of the inner pot, a temperature detecting element for detecting an upper side temperature of the heating plate, and an upper heating plate side detected by the temperature detecting element. An electric cooker comprising an amount detecting means for detecting an amount of the object to be cooked based on the temperature gradient of the electric cooker. 2. A detachable inner pot, a heating plate for heating a bottom portion and a side portion of the inner pot, a temperature detecting element for detecting an upper side temperature of the heating plate, and heating detected by the temperature detecting element. An electric cooker comprising abnormal state detection means for detecting a no-load state or an unattached state of the inner pot based on the temperature of the upper side of the plate.