JP2013022334A - Rice cooker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rice cooker having a heat-retention function of improving energy saving property by performing heat-retention with a small amount of power consumption only for preventing dew attachment on a lid.SOLUTION: The rice cooker includes: a double-structure vacuum container 6 constituting the inner wall of a body 1 and configured by a vacuum layer 6h inside; an inner pot 2 to be stored in the vacuum container 6; a lid body 31 for covering the body 1 and the inner pot 2; a heating means 9 for heating the inner pot 2; a temperature sensor 16 for detecting temperature on the bottom surface of the inner pot 2 thereby to detect the temperature of cooked rice; and a control means 5 for supplying power to the heating means 9 in accordance with the detection temperature of the temperature sensor 16. When a heat-retention operation is set, the control means 5 does not supply power to the heating means 9, detects the temperature of the cooked rice inside the inner pot 2, and stops the heat-retention operation when the temperature becomes equal to or less than specific temperature.

Description

  The present invention relates to a rice cooker, and more particularly to a rice cooker having a heat retaining function.

  In conventional rice cookers equipped with this type of heat retention function, if the rice is kept warm at a high temperature for a long period of time, it will cause a problem such as discoloration of the rice or drying of the rice, and much power to maintain the high temperature. There was a bug that required. In addition, if the temperature is kept at a low temperature, there is a problem that the odor of the rice is caused by the spoilage bacteria, or the rice is spoiled.

  Therefore, in recent years, as shown in Patent Document 1, as a method for solving such a problem, a cooked rice warming container has been proposed in which heat is kept by repeatedly heating at a high temperature after being kept at a low temperature for a certain period of time.

JP-A-8-299168

  In recent years, there has been a strong demand for eating delicious rice, and it has been demanded that cooked rice can be eaten as well as freshly cooked.

  In addition, there is a growing interest in energy conservation.

  What is shown in the above-mentioned Patent Document 1 does not cover the rice with a heat insulating structure with good heat retention, so it is necessary to heat the rice frequently during the heat insulation, the rice is not a little dried, There is a problem of needing electric power.

  In order to solve the above-mentioned problem, in claim 1, a double-structured vacuum vessel comprising an inner wall of a main body and having an inner portion constituted by a vacuum layer, an inner pot accommodated in the vacuum container, the main body and the inner pot are provided. A lid for covering, a heating means for heating the inner pot, a temperature sensor for detecting the temperature of the rice by detecting the temperature of the bottom surface of the inner pot, and power to the heating means in accordance with the detected temperature of the temperature sensor And a control means for detecting the temperature of the rice in the inner pot without supplying power to the heating means when the heat retention operation is set, and the temperature is a specific temperature. The heat retention operation was stopped when the following occurred.

  According to a second aspect of the present invention, a heater for preventing condensation is provided above the inner hook, and the heater is energized during the heat retaining operation.

  ADVANTAGE OF THE INVENTION According to this invention, the heat radiation from the rice after cooking can be suppressed, and the heat-retaining operation | movement rice can be hold | maintained in a deliciously warm state with little power consumption.

It is a figure which shows the cross section of the rice cooker of one Example. It is a figure which shows the operation display part of the rice cooker of one Example. It is sectional drawing of the vacuum vessel of the rice cooker of one Example. It is explanatory block diagram of the control system of the rice cooker of one Example. It is an operation | movement transition diagram explaining the display at the time of the heat retention operation | movement of the operation display part of the rice cooker of one Example. It is an operation | movement figure of the specific heat retention operation | movement of the rice cooker of one Example.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS.

  In the cross-sectional view of the rice cooker in FIG. 1, the inner wall of the main body 1 includes a vacuum vessel 6. As shown in FIG. 3, the vacuum vessel 6 has a substantially cylindrical shape in which a vacuum layer 6h is formed between a double structure of an inner case 6a and an outer case 6b, and an upper opening 6f and a lower opening 6g. A side frame 21 is attached to the relief portion 6 k inside the upper portion of the vacuum vessel 6.

  The side frame body 21 is a stainless steel frame body having a substantially U-shaped cross section with an opening facing outward. The side frame 21 is provided with an upper heater 20 formed by winding a heater wire. The upper heater 20 is used for heating the upper portion of the inner hook 2 during heat insulation or the like to prevent dew condensation from occurring on the upper portion of the inner hook 2.

  The upper opening 6f of the vacuum vessel 6 is supported by a frame 8 provided on the upper part of the main body 1. The frame body 8 is provided with a ring-shaped inner pot mounting portion 8a.

  The inner pot 2 is detachably accommodated in the vacuum container 6 of the main body 1 through the upper opening 6f of the vacuum container 6. The inner hook 2 is provided with a flange portion 2 a around the entire upper surface opening, and is placed on the inner hook placing portion 8 a so that the inner hook 2 is held by the main body 1.

  A lid 31 composed of an inner lid 4 that covers the upper opening of the inner hook 2 and an outer lid 3 that covers the outer side of the inner lid 4 is provided at the upper portion of the main body 1 so as to be freely opened and closed. A flat lid heater 30 for heating the inner lid 4 is provided on the lower surface of the outer lid 3 inside the lid 31. The lid heater 30 is used to prevent dew condensation by heating the upper portion of the inner hook 2 and the inner lid 4 when keeping warm. The lid heater 30 and the upper heater 20 are referred to as a heater 50 that prevents condensation above the inner hook.

  A dish-shaped bottom container 7 is provided in the lower part of the vacuum container 6. A heating means 9 for heating the inner pot 2 and a temperature sensor 16 for detecting the temperature of the rice by detecting the temperature of the bottom face of the inner pot 2 are provided on the lower surface of the bottom container 7. In addition, since the heating means 9 should just be able to heat the inner pot 2, a sheathed heater may be used as a heating source, and the heating coil which induction-heats the inner pot 2 may be used. In this embodiment, an example in which a heating coil is used as the heating means 9 will be described.

  The main body 1 includes a control unit 5 that is a control unit that controls the power supplied to the upper heater 20, the lid heater 30, and the heating unit 9 based on information from the temperature sensor 16.

  The heating means 9 arrange | positioned in the lower surface of the bottom face container 7 and the cooling fan 15 which cools the control part 5 are provided.

  On the upper surface of the lid 31, there is provided an operation display section 37 provided with a heat retention button 38 (FIG. 2) for selecting a heat retention operation and a selection display section 32 a (FIG. 2) for displaying selection contents.

  In the operation display part 37 shown in FIG. 2, every time the rice cooking button 11 to be executed by the control means for reheating to the temperature suitable for eating the start of rice cooking or the temperature of the heat-retaining rice and a plurality of heat-retaining operations are pressed. In addition, a heat retention button 38 is provided for selecting and selecting in order.

  Also, a reservation button for inputting the setting button 51 to be operated when the setting is cut off or the heat insulation is turned off, and the time at which the reheating to the temperature suitable for eating is completed. The input means 48 and the function input means 49 which select and input the kind of rice, a menu, and how to cook are provided.

  The display unit 32 of the operation display unit 37 includes a liquid crystal display unit 32b that displays liquid crystal with 7 segments or characters, and a lighting display unit 32c that informs the user more strongly than the liquid crystal display 32b by lighting an LED or the like. The

  The liquid crystal display unit 32b includes a heat retaining display 41 for displaying the word “heat retaining” when retaining heat, and a heat retaining number display 41a for displaying the numbers “1” or “2” for the two heat retaining operation numbers.

  In addition, the lighting display unit 32 c includes a selection display unit 32 a that notifies that the specific heat retaining operation is selected by the heat retaining button 38. In the present embodiment, the selection display section 32a displays the characters “power saving and warming”.

  A block diagram of the control system will be described with reference to FIG.

  The conditions input to the control unit 5 include a temperature sensor 16 that is a temperature detection unit that detects the temperature of the inner pot 2 and inputs temperature information detected by the control unit 5, and, as described above, the operation display unit 37. There are a cooking rice button 11, a heat retention button 38, a turn-off button 51, a reservation input means 48 and a function input means 49.

  In addition, what is controlled by the control unit 5 with respect to the input is the heating means 9, the upper heater 20, the lid heater 30, the cooling fan 15, and the display unit 32 provided in the operation display unit 37 as described above.

  Further, the control unit 5 displays the selection display unit 32a for notifying that the specific heat retaining operation is performed when the specific heat retaining operation is selected from the plurality of heat retaining operations with the heat retaining button 38, and the rice in the inner pot 2 is not heated. In order to prevent the cover 31 from being dewed, when the electric power is supplied only to the upper heater 20 and the lid heater 30 and the temperature sensor 16 detects that the temperature of the inner pot 2 is lower than the specific temperature, the specific heat retaining operation is performed. A specific heat retaining operation means 91 is provided that stops and stops the supply of power to the upper heater 20 and the lid heater 30.

  The control unit 5 is an electronic control unit mainly composed of a microcomputer, and executes various control functions by software. Naturally, the reheating start means and reheating end proposed in this embodiment are performed. The function is given to the control unit 5 as an application executed by software or the like.

  Next, with reference to FIG. 5, a method for selecting a warming operation by the warming button 38 of the operation display unit 37 and a state transition of the display unit 32 will be described. There are three types of heat retention operations. It is a heat retention 1 operation, a heat retention 2 operation, and a specific heat retention operation.

  The heat insulation 1 operation and the heat insulation 2 operation are those described in the background art. The heat retention 1 operation is a heat retention period that keeps the temperature constant at about 74 ° C. so that the rice does not spoil during the heat retention, a heat retention time that keeps the temperature lower at 50-60 ° C., and a temperature of about 80 ° C. that prevents the growth of spoilage This is a heat-retaining operation that enables long-term heat retention while preventing the breeding of germs that occur in rice by periodically repeating a heat-retaining period that is kept at a high temperature.

  The heat retaining 2 operation is a heat retaining operation that keeps the temperature constant at about 74 ° C. so that the rice does not rot during the heat retaining. In the heat retention 1 operation, this is for setting when the user feels that the heat retention temperature is low.

  The specific heat-retaining operation of this embodiment is to keep the rice in the inner pot 2 without heating by the heating means 9 and to operate within a range where the rice can be eaten warmly without being spoiled. For this reason, when the temperature of the rice is lower than the above range, the specific heat retaining operation is stopped. In the present embodiment, the above range is up to 50 ° C., and when the temperature is 50 ° C. or less, the specific heat retaining operation is stopped (hereinafter, 50 ° C. is referred to as a specific temperature). However, the temperature of 50 ° C. is not particularly limited as long as the rice in the inner pot 2 is kept warm without being heated by the heating means 9 as described above, and the rice can be eaten warmly without rotting. Any number of times.

  Further, during the specific heat retaining operation, electric power is supplied to the heater 50 in order to prevent dew condensation that occurs at the top of the inner pot 2.

  The initial setting is the heat retention 1 operation and the first state. In the liquid crystal display unit 32b, the heat insulation display 41 displays “heat insulation”, and the heat insulation number display 41a displays “1”. The selection display part 32a of the lighting display part 32c is not displayed.

  Next, when the heat retaining button 38 is pressed, the heat retaining 2 operation is selected and the second state is entered. In the liquid crystal display unit 32b, the heat insulation display 41 displays “heat insulation”, and the heat insulation number display 41a displays “2”. The selection display part 32a of the lighting display part 32c is not displayed.

  Next, when the heat retaining button 38 is pressed, the specific heat retaining operation is selected and the third state is entered. In the liquid crystal display part 32b, the heat insulation display 41 displays “heat insulation” and the heat insulation number display 41a is not displayed. The selection display part 32a of the lighting display part 32c displays.

  Next, when the heat retention button 38 is pressed, the heat retention 1 operation is selected and the first state is restored. In the liquid crystal display unit 32b, the heat insulation display 41 displays “heat insulation”, and the heat insulation number display 41a displays “1”. The selection display part 32a of the lighting display part 32c is not displayed.

  Next, the operation of the above configuration will be described.

  FIG. 6 shows a case where the heat retaining operation after cooking rice is set by selecting the specific heat retaining operation. When rice cooking is completed and the process proceeds to heat insulation, the supply of power to the heating means 9 is stopped, and power is supplied only to the upper heater 20 and the lid heater 30. Then, the temperature of the rice in the inner pot 2 gradually decreases from about 100 ° C. immediately after the completion of the rice cooking due to the heat capacity of the inner pot 2 and the heat capacity of the rice in the inner pot 2 due to the highly insulated structure by the vacuum vessel 6. Go. And it continues until it detects that the temperature sensor 16 fell below about 50 degreeC.

  Here, the operation of keeping the temperature of the rice at a predetermined temperature by supplying electric power to the heating means 9 and induction heating the inner pot 2 is not performed. Therefore, by not heating the inner pot 2 positively, water vapor is not actively emitted from the rice. Thereby, the upper heater 20 and the lid heater 30 are kept in a state in which the dew of the lid 31 is not attached by supplying a smaller amount of electric power than during rice cooking.

  When the specific heat-retaining operation is performed after rice cooking, the time until the temperature sensor 16 detects that the temperature has decreased below about 50 ° C. differs in the following cases. First, when the amount of cooked rice is large, the heat capacity of the rice is larger than when a small amount is cooked, and it is detected that the temperature sensor 16 has fallen below about 50 ° C. after a long period of time. In the case of a 5.5-go rice cooked product, it takes 3 hours for about 5 hours. In addition, since the amount of heat radiation increases at about 5 ° C. compared to room temperature of about 20 ° C., it takes about 1 hour 30 minutes when cooking one rice with a small heat capacity. In addition, if the specific heat-retaining operation is performed after mixing rice with plump immediately after cooking, the temperature is lowered by mixing with room air rather than after cooking, so it takes about 1 hour when cooking 3 meals. .

  From the above, during the specific heat-retaining operation, the rice does not rot and operates in a range where the rice can be eaten warmly. The temperature sensor 16 allows the temperature of the rice in the inner pot 2 to reach a specific temperature (about 50 ° C.). ) Is detected, the specific heat-retaining operation is stopped without heating the heat-retaining rice by the heating means 9.

  And the selection display part 32a is light-extinguished and the display of the heat insulation label | marker 41 is light-extinguished. The user can not only know that the heat insulation has been completed by turning off the selection display portion 32a that has been informed to the user strongly by turning on this LED, but can also serve the rice in the inner pot 2 When trying to eat, even if the temperature is low, it can be recognized that it is a normal operation by the specific heat retention operation set by the user.

  As described above, in this embodiment, by providing a highly heat-insulated vacuum container, heat dissipation from cooked rice is suppressed, and during heat-retaining operation, cooked rice with less power consumption is tasty and moderately warm. be able to.

DESCRIPTION OF SYMBOLS 1 Main body 2 Inner hook 3 Outer lid 4 Inner lid 5 Control part 6 Vacuum container 6a Inner case 6b Outer case 6f Upper opening part 6g Lower opening part 6h Vacuum layer 7 Bottom container 9 Heating means 11 Rice cooking button 16 Temperature sensor 20 Upper heater 21 Side frame body 30 Cover heater 31 Cover body 32a Selection display section 37 Operation display section 38 Thermal insulation button 50 Heater

Claims (2)

  A double-structured vacuum vessel that forms the inner wall of the main body and the inside is constituted by a vacuum layer, an inner pot accommodated in the vacuum container, a lid that covers the main body and the inner pot, and heating that heats the inner pot Means, a temperature sensor for detecting the temperature of the bottom of the inner pot to detect the temperature of the rice, and a control means for supplying electric power to the heating means in accordance with the temperature detected by the temperature sensor, the control means Is configured to detect the temperature of the rice in the inner pot without supplying electric power to the heating means when the heat retention operation is set, and stop the heat retention operation when the temperature falls below a specific temperature. Rice cooker.   The rice cooker according to claim 1, wherein a heater for preventing condensation is provided above the inner pot, and the heater is energized during the heat retaining operation.