JPH067616U - rice cooker - Google Patents

Abstract

(57) [Summary] [Purpose] To completely prevent the attachment of soup to the lid during heat retention. [Structure] The control means 25, 28 controls the heating means 7 to sequentially execute the rice cooking process, and then detects the rice temperature detected by the rice temperature detecting device 9 and the lid temperature detecting device 19 in the heat retaining process. The body heating means 8 and the lid heating means 18 are controlled on the basis of the lid temperature to maintain the temperature. The lid temperature control temperature by the control means 25, 28 is constantly higher than the rice detection temperature by the rice temperature detection means 9 so that the temperature of the lid 17 does not fall below the rice temperature. Thereby, the steam in the rice cooking container 5 is not cooled and condensed by the lid 17, and the attachment of the soup to the lid 17 is prevented.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a rice cooker, and more particularly to a rice cooker that prevents the sauce from adhering to the lid during heat retention.

[0002]

[Prior art]

Generally, in a rice cooker, when the steaming process is completed and the rice cooking is completed, the process proceeds to the heat retaining process and the heat retention heater is turned on / off to keep the cooked rice at a predetermined temperature. ing. During this heat retention, the water vapor generated in the rice cooker is cooled by the lid with a small heat capacity and solidifies to form sauce, which then adheres to the inner surface of the lid, causing the sauce to drop onto the rice and cause it to cook. Whitening occurs, and when the lid is opened, the soup may spill around. Therefore, conventionally, in order to prevent such soup from adhering to the lid, a heater is provided on the lid to heat the lid in addition to the above-mentioned heat-retaining heater. Specifically, as shown in FIG. 6, after the rice is cooked, the temperature of the lid is adjusted to a constant temperature Tb ₁ until the temperature of the rice falls to a predetermined transition temperature Ta ′, and then the temperature of the rice is adjusted to a constant temperature Ta. While adjusting the temperature, the temperature of the lid is adjusted at a temperature Tb ₂ (= Ta + Δ) which is higher than the rice temperature adjustment temperature Ta by a constant temperature Δ.

[0003]

[Problems to be solved by the device]

However, when the controlled temperature of the lid is changed from Tb ₁ to Tb ₂ , the temperature of the lid, which has a smaller heat capacity than rice, drops rapidly below the temperature of the rice, as shown in Fig. 6, and soup is attached to the lid. There was something to do. For this reason, it was not possible to avoid the problems such as the above-mentioned whitening of rice and the outflow of soup sauce. The present invention has been made in view of the above problems, and an object of the present invention is to provide a rice cooker capable of completely preventing attachment of soup to the lid during heat retention.

[0004]

Means for Solving the Problems In order to achieve the above object, the present invention provides a main body for accommodating a rice cooking container in an inner case, a lid having a heat dissipation plate covering the above rice cooking container, and the rice cooking device. Rice heating means for heating the container, body heating means for heating the inner shell to keep the rice cooking container warm, lid heating means for heating the radiator plate to keep the rice cooking container warm, and the temperature of the side surface of the rice cooking container. The rice temperature detecting means for detecting the rice temperature, the lid temperature detecting means for detecting the temperature of the heat sink, and the heating means are controlled to sequentially execute the rice cooking process, and then the rice temperature detecting means detects the rice temperature in the heat retaining process. And a control means for controlling the temperature of the lid heating means and the lid heating means based on the cooked rice temperature and the lid temperature detected by the lid temperature detecting means, and controlling the lid temperature controlled by the control means. From the temperature detected by the rice temperature detection means It is obtained by constant temperature high in.

[0005]

[Action]

 According to the above configuration, the lid temperature control temperature at the time of heat retention is always higher than the rice detection temperature by a constant temperature, so that the lid temperature does not fall below the rice temperature. Therefore, the steam in the rice cooking container is not cooled and condensed by the lid, and the attachment of the sauce to the lid is prevented.

[0006]

【Example】

 Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a rice cooker according to the present invention, in which 1 is a main body and 2 is an openable / closable lid. The main body 1 is provided with an inner bottom 3 and an inner case 4, and a rice cooking container 5 is accommodated in the inner case 4. A coil mount 6 is provided below the inner bottom 3, and an induction heating coil 7 is arranged between the coil mount 6 and the inner bottom 3. A body heater 8 is arranged on the outer peripheral surface of the inner body 4. Further, a bottom temperature sensor 9 is provided below the inner case 4, and a side temperature sensor 10 is provided above it. The bottom temperature sensor 9 is in pressure contact with the outer surface of the rice cooking container 5 near the bottom, and the side temperature sensor 10 is in contact with the outer surface of the rice cooking container 5 above the bottom temperature sensor 9. A first control board 11 is provided below the coil mount 6, and a second control board 12 is provided in front of the inner case 4. The second control board 12 is provided with an operation display panel 15 on which a rice cooking switch 13, a rice cooking switch 14, and the like are arranged.

On the inner surface of the lid body 2, a heat radiating plate 17 is attached which comes into pressure contact with the upper end flange portion of the rice cooking container 5 via a seal packing 16. A lid heater 18 and a lid temperature sensor 19 are attached to the upper surface of the heat dissipation plate 17. FIG. 2 shows an electric circuit of the rice cooker shown in FIG. A full-wave rectifier circuit 21 is connected to the AC power supply 20, and an induction heating coil 7 and a transistor 22 are connected in series to the output terminal of the full-wave rectifier circuit 21. A resonance capacitor 23 is connected in parallel to the induction heating coil 7, and a diode 24 is connected in parallel to the transistor 22. A transistor control circuit 25 that controls the transistor 22 is connected to the base of the transistor 22.

A body heater 8 and a lid heater 18 are connected in parallel to the AC power source 20 via triacs 26 and 27, respectively. The rice cooking control circuit 28 has a DC power supply circuit for obtaining a DC power supply Vcc from the AC power supply 20 and a microcomputer. Temperature sensors 9, 10, and 19 are connected in parallel to the DC power supply Vcc, and reference resistors 29, 30, and 31 are connected in series to the temperature sensors 9, 10, and 19, respectively. The microcomputer of the rice cooking control circuit 28 cooperates with the built-in timer based on the temperature detection signal input as the divided voltage between the temperature sensors 9, 10, 19 and the reference resistors 29, 30, 31. By executing the program by executing the program, the control signal is output to the transistor control circuit 25 to control the heating by the induction heating coil 7, while the drive signal is output to the triacs 26 and 27 via the relays 32 and 33. The body heater 8 and the lid heater 18 are controlled.

The control operation of the rice cooker having the above configuration will be described below with reference to the flowchart shown in FIG. First, in step 101, a rice-sorting menu using the rice-rice sorting switch 14, that is, soft rice, firm or firm, is accepted, and in step 102, the rice cooking switch 13 is turned on, and then in step 103, the rice cooking process is sequentially performed. Run. As shown in FIG. 5, this rice cooking process is performed in the order of preheating 1, preheating 2, middle pappa, electric power control I, electric power control II, cooking, and spotting. In the preheating 1 step, the heating is not performed, and the process stands by for 1 minute. In the preheating 2 step, the temperature of the rice cooking container 5 is adjusted to 60 ° C. based on the temperature detected by the bottom temperature sensor 9 by controlling the induction heating coil 7 on / off and the body heater 8 on / off for 20 minutes. By controlling the on / off of the lid heater 18, the temperature of the heat sink 17 is adjusted to 85 ° C. based on the temperature detected by the lid temperature sensor 19.

For the on / off control of the induction heating coil 7, the rice cooking control circuit 28 outputs an on / off signal and a necessary input power signal to the transistor control circuit 25 based on the temperature detected by the bottom temperature sensor 9. Done by. That is, when the ON signal and the input power signal of 65% are input from the rice cooking control circuit 28, the transistor control circuit 25 drives the transistor 22 so that the power is 65%, and the induction heating coil 7 and the capacitor 23 are connected. To oscillate the LC resonant circuit. As a result, the rice cooking container 5 placed above the induction heating coil 7 generates heat to heat the water and rice inside. If the signal from the rice cooking control circuit 28 is off, the transistor control circuit 25 stops driving the transistor 22, and as a result, heating is stopped.

In addition, for the on / off control of the body heater 8, the rice cooking control circuit 28 outputs an on / off signal to the relay 32 based on the detected temperature from the bottom temperature sensor 9 to turn on the triac 26. , It is turned off and the energization to the body heater 8 is controlled. The ON / OFF control of the lid heater 18 is similarly performed. By this preheating step, as shown in FIG. 5, the temperature detected by the bottom temperature sensor 9 equilibrates at 60 ° C., and the temperature detected by the side temperature sensor 10 at a position distant from the bottom temperature sensor 9 equilibrates later than this. To do. Further, the temperature detected by the lid temperature sensor 19 is in equilibrium at 85 ° C.

[0012] In the middle tapping process, the temperature detected by the side temperature sensor 10 is controlled by an inverter control of the induction heating coil 7 so that the temperature rises at a constant rate of rise that differs for each cooking. The inverter control of the induction heating coil 7 is performed by the rice cooking control circuit 28 outputting an ON signal and an input power signal to the transistor control circuit 25. The input power signal is adjusted so that the temperature rise rate is constant. In this mid-pappa process, a certain pattern of the body heater 8 is turned on and off, and the lid heater 18 is turned on and off based on the temperature detected by the lid temperature sensor 19 to radiate the heat. Is temperature adjusted to 85 ° C. In addition, the rice cooking control circuit 28 calculates the amount of electric power input within a fixed time while determining the amount of rice to be cooked based on the magnitude of the amount of electric power input, while the middle-papper process is performed.

When the temperature detected by the side temperature sensor 10 reaches a predetermined transition temperature that varies depending on the type of rice cooked and the amount of rice cooked, the process proceeds to the power control I process, in which the induction heating coil is operated for a predetermined time. The inverter control of 7 heats for a predetermined time with constant power. Further, in the power control I step, the body heater 8 is controlled to be turned on and off in a fixed pattern, and the lid heater 18 is turned on and off to adjust the temperature of the radiator plate 17 to 85 ° C. In the electric power control II step, the induction heating coil 7 is controlled by an inverter to heat the electric power with a constant electric power for a predetermined time which is different for each cooking. In the electric power control II step, ON / OFF control of a fixed pattern of the body heater 8 is performed, and the temperature of the heat radiating plate 17 is adjusted to 125 ° C. by ON / OFF control of the lid heater 18. The control of the body heater 8 and the lid heater 18 is continued until the stripping process.

In the cooking process, the induction heating coil 7 is controlled by an inverter to heat with different electric power and time depending on the amount of rice cooked and the amount of rice cooked. If the temperature detected by the bottom temperature sensor 9 reaches about 108 ° C. Move to the process. In the Murashiri process, after heating by the induction heating coil 7 is stopped and the Murashi 1 is performed for a predetermined time, the induction heating coil 7 is turned on and off to control the cooking time and the amount of cooked rice to be different for a certain time. Heat and cook twice for 1. Next, after the rice 2 has been cooked twice after the rice 2 has been cooked for a predetermined time, the rice 3 is cooked for a predetermined time and the rice cooking is completed.

When the above rice cooking process is completed, as shown in FIG. 3, the heat retaining process is executed in steps 104 to 106. That is, first, in step 104, the heat retention step 1 is executed. In this warming 1 step, the heat radiation plate 17 is temperature-controlled to a constant temperature Tb ₁ (125 ° C.) by controlling ON / OFF of the lid heater 18 based on the temperature detected by the lid temperature sensor 19. As a result, as shown in FIG. 4, the lid temperature is maintained at Tb ₁ (125 ° C.), but the temperature of the rice cooking container 5 is lowered by natural cooling. If the bottom temperature sensor 9 detects the predetermined temperature Ta '(95 ° C.) in step 105 during the execution of the heat retention 1 step, the process moves to the heat retention 2 step of step 106.

In the heat retention 2 step, the temperature of the rice cooking container 5, that is, the rice temperature is adjusted to a constant temperature Ta (72 ° C.) by controlling the on / off of the body heater 8 based on the temperature detected by the bottom temperature sensor 9. As a result, the rice temperature is naturally lowered by cooling until the bottom temperature sensor 9 detects the transition temperature Ta ′ (95 ° C.) from the heat retention 1 to the first detected temperature Ta (72 ° C.). Go on. On the other hand, in addition to the temperature adjustment of the rice temperature, the temperature adjustment of the radiator plate 17 is performed. The lid temperature control temperature Tb ₂ is set to a temperature Tas + Δ which is higher than the temperature Tas detected by the bottom temperature sensor 9 by a constant temperature Δ. As a result, as shown in FIG. 4, the rice temperature is adjusted in proportion to the natural cooling from the transition point, so that the rice temperature does not fall below the rice temperature. Therefore, the water vapor in the rice cooking container 5 is not cooled and condensed by the heat radiating plate 17 having a temperature higher than the rice temperature, and there is no fear that the soup will adhere.

[0017]

[Effect of device]

 As is clear from the above explanation, according to the present invention, the lid is always adjusted to a temperature higher than the rice temperature during the heat retention, and the temperature does not drop below the rice temperature, so that the sauce is completely attached to the lid. To be prevented. Therefore, the rice does not turn white during heat retention, and the rice can be kept warm. In addition, since the soup does not leak when the lid is opened, it is safe.

[Brief description of drawings]

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

FIG. 2 is an electric circuit diagram of the rice cooker shown in FIG.

FIG. 3 is a flowchart of a rice cooking process.

FIG. 4 is a diagram showing a temporal change in temperature detected by a bottom temperature sensor and a lid temperature sensor during heat retention.

FIG. 5 is a diagram showing temporal changes in temperature and electric power detected by each temperature sensor from rice cooking to heat retention.

[Fig. 6] Fig. 6 is a diagram showing changes over time in the temperatures detected by the bottom temperature sensor and the lid temperature sensor during heat retention in a conventional rice cooker.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Main body, 2 ... Lid body, 4 ... Inner body, 5 ... Rice cooking container, 7 ... Induction heating coil (rice cooking heating means), 8 ... Body heating heater (body heating means), 9 ... Bottom temperature sensor (rice temperature detection) Means), 17 ... radiating plate (lid), 18 ... lid heater (lid heating means), 19 ... lid temperature sensor (lid temperature detecting means), 25 ... transistor control circuit (control means), 28 ... rice cooking control circuit (control) means).

Claims (1)

[Scope of utility model registration request] 1. A main body for accommodating a rice cooking container in an inner case, a lid body having a heat radiating plate for covering the upper side of the rice cooking case, a rice heating means for heating the rice cooking case, and a heating means for heating the inner case. The body heating means for keeping the rice cooking container warm, the lid heating means for heating the heat dissipation plate to keep the rice cooking container warm, the rice temperature detecting means for detecting the rice temperature by the temperature of the side surface of the rice cooking container, and the temperature of the heat sink. After performing the rice cooking step by controlling the lid temperature detecting means for detecting and the heating means, the rice temperature detected by the rice temperature detecting means in the heat retaining step and the lid temperature detected by the lid temperature detecting means A control means for controlling the temperature of the body heating means and the lid heating means based on the above, and controlling the lid temperature by the control means to be constantly higher than the rice temperature detection temperature by the rice temperature detection means. Rice cooker.