JPH062100B2 - Rice cooker - Google Patents

Description

Description: [Industrial application] The present invention relates to a rice cooker and, in particular, to control a heat-retaining process in a configuration in which a lid of an inner pot is heated by heat conduction from a heat-retaining heater provided on a shoulder. The present invention relates to a rice cooker jar capable of appropriately controlling a heater keeper to prevent dew dripping during a warming operation.

[Prior Art] The rice cooker jar currently on the market is a combination of an electric rice cooker and a jar.

In such a rice cooker, a heater is provided at the bottom of the inner pot, and heating power is supplied to the heater to cook rice. Further, a warming heater is provided in the inner pot for the purpose of keeping warm, or in the body of the inner pot housing container, and after the rice is cooked, energization of the warming heater is controlled to keep the cooked rice warm. This is so that cooked rice can be eaten in a warm state at all times.

In addition, for the purpose of cooking delicious rice, the temperature of the pan inside the rice is measured by a controller equipped with a temperature sensor and a microcomputer, and the temperature or temperature rise data is input to the microcomputer to determine the rice cooking capacity. As a result, a microcomputer-controlled automatic rice cooker has been developed that is capable of performing appropriate power control according to the rice cooking capacity.

[Problems to be Solved by the Invention] Such an automatic rice cooker controlled by a microcomputer is
Even in the warming process control, the warming process control can be finely controlled by the program control, but in the conventional warming process control, when the temperature of the inner pot is lowered, the temperature is detected by the temperature sensor provided at the bottom of the inner pot, It is heat retention control that keeps the temperature of the inner pot at a constant heat retention temperature. Therefore, in the rice cooker, there is a problem that the temperature of the rice cooker is lowered relatively quickly and dew is deposited around the lid away from the position where the heater is arranged.

Also, the shoulder part of the inner pot storage container is a part near the opening and closing part of the lid part of the rice cooker body and outside air easily enters, and heat dissipation around this shoulder part lowers the heat retention temperature around the shoulder part. was there.

Further, in the structure in which the lid of the inner pot is heated by radiant heat by the heat retaining heater provided on the lid of the rice cooker body, since the heat retaining heater is heated by radiant heat, this inner heater is heated before the inner pot is heated. It took a long time for the lid to reach a predetermined temperature, and there was a dislike that it was affected by the outside air temperature. Therefore, when correlating the thermal relationship with another warming heater that heats the inner pot side part, since this inner pot side part is also heated and kept warm by radiant heat, there is a time difference from the heating and keeping of the inner pot lid part. Difficulty was required to ensure the installation.

Along with this, a heat-retaining jar with a lid heater, which has a heat-retaining heater on the lid, has been developed to prevent dripping of dew from the lid. Since the electrical connection for energizing the thermal insulation heater must be made through the hinge part between the heat insulation jar body and the heat insulation jar body, the electrical connection of the hinge part of the movable part becomes the movable part and there is a possibility that dew accumulates. There is a problem in that the heat insulating jar becomes expensive in order to form a hinge portion having low reliability and high electric connection reliability.

The present invention has been made to solve the above problems.

An object of the present invention is to provide a rice heating jar that effectively prevents dripping of dew by energizing the heaters by heating control of the shoulder warmer and the body warmer.

The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the rice cooker jar of the present invention is stored in a rice cooker main body including a lid and a main body having an inner pan storage container, and an inner pan storage container. Rice cooker provided at the bottom of the inner pot, a first heat retaining heater provided at the shoulder of the inner pot storage container, a second heat retaining heater provided at the body of the inner pot storage container, and a rice cooking process control and heat retaining process. A rice heating / warming jar having control means for controlling energization of each heater, wherein the control means controls the heating step after controlling the cooking step, and in the heater control of the heating step control, the shoulder part The lid of the inner pot is heated by the heat conduction from the first warming heater, and the side portion of the inner pot is heated by the radiant heat from the second warming heater of the body part. From the heat retention control temperature of the heat retention heater In addition to the high temperature, the heater energization for the heat retention control of the first heat retention heater is started earlier than the heater energization for the heat retention control of the second heat retention heater.

[Operation] According to the means described above, in the rice cooker jar, the warming heater (first warming heater) is provided on the shoulder portion of the inner pot storage container, and the warming heater (second warming heater) is provided on the body part of the inner pot storage container. ) Is provided. The heater energization control of the first warming heater provided on the shoulder portion controls the temperature of the first warming heater and the second warming heater so as to generate a larger amount of heat than the heater energization control of the second warming heater provided on the body portion. Do a good balance. As a result, the shoulder part of the inner pot storage container is a part near the opening and closing part of the lid part of the rice cooker and outside air easily enters, and this heat dissipation around the shoulder part lowers the heat insulation temperature around the shoulder part. However, since the heat retention temperature by the first heat retention heater on the shoulder of the rice heating jar can be increased, a large amount of heat from the heat retention heater (first heat retention heater) can be conducted from the shoulder part where the temperature drops quickly to the lid part. It is possible to prevent a decrease in the heat retention temperature around the shoulder portion, and to uniformly prevent the dew drop of the lid portion during the heat retention operation.

Along with this, the rice heating jar includes a rice heating heater provided at the bottom of the inner pan for cooking rice, a first warming heater on the shoulder of the inner pan storage container, and a second warming heater on the body of the inner pan storage container. In the heat retention process control after the rice cooking process control provided by the control means, energization control of these heaters is performed. In the heat retention process control performed after performing the rice cooking process control, the rice cooking heater provided at the bottom of the inner pan is prevented from being energized, and the heat retention control temperature of the first heat retention heater on the shoulder is controlled by the heat retention control of the second heat retention heater on the body. The temperature is higher than the temperature. In the heat retention process control, in the heater energization control, the heater energization for the heat retention control of the first heat retention heater is started earlier than the heater energization control for the heat retention control of the second heat retention heater, and the first heat retention control heater for the shoulder portion is also started. The inner pot lid is heated by heat conduction from.

As a result, in the rice cooker jar, the heat generated from the heater is transmitted to the lid part of the rice cooker pot where the temperature drops quickly, not by heat radiation but by heat conduction. The heat from the heat retaining heater can be surely transferred to the lid of the inner pot quickly (by making the shoulder heat retaining heater generate a higher heat retaining temperature), and the heater energization of the heat retaining control of the first heat retaining heater is maintained by the second heat retaining heater. Coupled with the fact that the energization starts earlier than the heater energization for control,
The lid part of the inner pan can be heated to a higher temperature surely faster than the side part of the inner pan, and the warming operation can be performed, and the dew drop from the lid part is prevented during the warming operation. In addition, by raising the heat retention temperature of the upper part of the rice cooker faster during heat retention operation, the heat retention temperature of the lower part of the rice cooker is maintained without increasing it, preventing evaporation of water from the rice and causing so-called rice discoloration. Prevent browning.

Therefore, according to this rice heat insulation jar, when the user uses the rice from the rice heat insulation jar when the rice is cooked and kept warm, there is no dripping of dew, which improves usability and prevents browning of the rice. it can.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a cutaway sectional view of a rice cooker heat insulating jar according to an embodiment of the present invention. In FIG. 1, 1 is a rice cooker body, 2 is a lid portion of the rice cooker body 1, 3 is a body portion of the rice cooker body 1, and 4a is a shoulder portion of an inner pot storage container 5 described later when the lid portion 2 is closed. It is the lid portion of the inner pot 4 which abuts the peripheral edge. Body 3
Is an inner pot 4, an inner pot container 5 for storing the inner pot, a rice cooking heater 6 at the bottom of the inner pot, a temperature sensor 7 provided in contact with the bottom of the inner pot 4, and a shoulder portion of the inner pot container 5. The inner pot lid 4a is heated by heat conduction.

Heat-retaining heater (first heat-retaining heater; hereinafter referred to as shoulder heat-retaining heater) 8, heat-retaining heater (second heat-retaining heater; hereinafter referred to as "body") that is provided on the body of the inner pot container and heats the side of the inner pot 4 by radiant heat. 9), a control unit 10 incorporating a microcomputer and the like are provided inside.

Reference numeral 11 is a function display selection operation unit. The function display selection operation unit 11 is arranged at the upper position of the rice cooker body 1. The function display selection operation unit 11 includes a plurality of operation key switches, light emitting diodes for displaying various states, and time display. A 7-segment character display is provided. The operation key switches include hour key switches, minute key switches, reserved key switches, menu key switches, start key switches, and cancel key switches.

FIG. 2 is a front view showing a panel surface of the function selection operation unit. In FIG. 2, 12 is a character display,
For example, it is a 4-digit number display liquid crystal module that displays the characters of each display digit in 7 segments. This character display 1
In 2, a time is displayed and a reserved time for reserved rice cooking is displayed. 13a is a key switch for operating the hour digit, 13b is a minute key switch for operating the minute digit, 13c is a reservation key switch for instructing reservation, and 13d.
Is a menu key switch for instructing the rice cooking menu, 13
Reference numeral e is a start key switch for instructing the start of rice cooking operation operation or reserved rice cooking operation, and 13f is a cancel key switch for canceling each operation. Further, 14 is a status display section for displaying the operation mode. This status display unit 14
Is provided with a plurality of light emitting diodes that display various states of the rice cooker jar. Here, in order to display the states of reservation mode distinction, rice cooking menu type of rice cooking control, and heat insulation mode distinction as states to be displayed, "reservation 1", "reservation 2", "white rice",
Various states are displayed by turning on the light emitting diodes labeled "early cooked", "rice cooked", "rice cooked", "brown rice", "porridge", "warm", and "freshly cooked warm". ing.

FIG. 3 is a block diagram showing a configuration of a main part of a control unit using a microcomputer. In FIG. 3, 6 is a rice cooking heater, 7 is a temperature sensor, 8 is a shoulder warmer heater, 9 is a body warmer heater, 10 is a control unit, and 11 is a function display selection operation unit. As described above, the function display selection operation unit 11 is provided with the 7-segment character display 12, the operation key switches 13 (13a to 13f), and the light emitting diode of the status display unit 14. Further, 15 is a commercial AC power supply, and 16 is a thermal fuse. The control unit 10 has
A relay 17 for switching between rice cooking mode and warming mode, a triac 18 for controlling energization of the rice cooking heater 6, a triac 19a for controlling energization of the shoulder warming heater 8, and a triac 19b for controlling energization of the body warming heater 9. A microcomputer 20, a clock mechanism 21, a buzzer 22 and the like are provided. The temperature sensor 7 is composed of a thermistor or the like, detects the temperature, and outputs an electric signal corresponding to the temperature. The electrical signal of temperature is input to the analog / digital conversion port of the microcomputer 20. The microcomputer 20 includes a processing device CPU, a memory RAM,
It has a program memory ROM, an input port having an analog / digital conversion function, a plurality of input ports for receiving key switch inputs, an output port for outputting a control output signal and a display control signal, etc., and is stored in the program memory. According to the program, a predetermined output signal is output from the output port in response to the input from the input port. That is, the microcomputer 20 receives inputs from the temperature sensor 7, the timepiece mechanism 21, and the operation key switch 13, performs a series of processes in accordance with a processing program contained therein, and sends a control signal to a triac for controlling energization of the heater. At the same time as sending, a lighting control signal to the light emitting diode of the status display unit 14 is sent in order to display the status such as the operation mode. Further, the time signal from the clock mechanism 21 is input to the microcomputer 20, the time is displayed on the character display 12, and the microcomputer 20 is used as a signal for determining the reserved time when timer reserved rice is cooked.
It is input and used in.

Next, the operation of the rice cook heat insulation jar thus configured will be described focusing on the heat insulation operation after cooking rice.

FIG. 4 is a flowchart showing an outline of the overall control flow of the microcomputer. This will be described with reference to FIG.

When the power is turned on, in step 31, rice cooking control preprocessing is performed. In this rice cooking control preprocessing, initialization processing for resetting various internal registers, timers, etc. of the microcomputer is performed, and rice cooking menu instruction settings, rice cooking reservation time settings, and other rice cooking operation instruction data setting processing are performed. When the key switch is turned on, or when the reserved time comes in the case of reserved rice cooking, the processing from step 32 is performed. In step 32, the relay is turned on and the rice cooking heater circuit is turned on to control the rice cooking.
Next, the rice cooking process control of step 33 is performed. This allows
Rice cooking operation is performed to cook rice. When the rice cooking operation is completed, next, in step 34, the relay is turned off, the rice cooking heater circuit is turned off, and the heat retention control mode is performed to perform the heat retention control for keeping the cooked rice warm. In the heat retention control mode, the processing from step 35 is performed.

In this heat retention control mode, normal heat retention control is performed in step 35, and in the next step 36, it is determined whether or not there is a temperature abnormality. If the temperature is abnormal, error processing such as abnormality notification and abnormality display is performed in step 37, and the entire processing ends. If the temperature is not abnormal in step 36, the process returns to step 35 to repeat the normal heat retention control.

Next, a schematic operation of the rice cooking control by the microcomputer control thus configured will be described.

When a desired amount of rice and water corresponding to it are put in the inner pot 4 and the start key switch is turned on, the microcomputer 20 of the control unit 10 performs the processing step of the rice cooking program stored in the program memory ROM therein. Therefore, power control for heating in the rice cooking process is started. At this time, the microcomputer 20 converts the voltage output from the temperature sensor 7 into a digital amount from the input port A / D of the analog / digital conversion function, inputs the digital amount, and converts the input temperature into the temperature. Judge,
Various rice cooking processes will be controlled based on the temperature determination result. To explain the outline of this rice cooking process, in the early stage of rice cooking, a water absorption process is performed in which the heating power is reduced and the rice absorbs water. Next, the heating power is increased, the temperature is rapidly raised, and a boiling step of boiling is performed, and then a boiling maintaining step of continuing boiling is performed. This boiling maintenance process continues, the rice absorbs enough water and the water in the bottom of the inner pot disappears,
When the temperature reaches a predetermined temperature, for example, 130 ° C., the microcomputer 20 detects this temperature and turns off the heater for heating to end the boiling maintaining step. Next, during a predetermined time period, the first muddling step, the first additional cooking step, the second uneven cooking step, the second additional cooking step, etc. are performed, and finally the heat retention step is reached and the rice cooking step is completed. When the rice cooking process control is completed, the process proceeds to the heat retention process control.

FIG. 5 is a diagram showing temperature changes of rice and lid temperature in the heat retention mode for explaining the heat retention control. Also,
FIG. 6 is a flowchart showing the processing flow of heat retention control.

The operation of the heat retention control in the rice cooking heat retention jar will be described with an example of the heat retention process control after the rice cooking process control ends and the rice cooking control ends. First, with reference to FIG. 5, an outline of the whole heat retention control will be described, and then the freshly cooked heat retention control will be described according to the flowchart of FIG.

As shown in FIG. 5, when the rice cooking operation of cooking rice in the rice cooker jar is completed at time t ₁ , the operation mode is to perform the heat keeping control. Since the temperature of the rice is sufficiently high at time t ₁ immediately after the rice is cooked, the energization control of the body heat retaining heater and the shoulder heat retaining heater is not performed even in the heat retaining control mode. When the temperature of the rice drops and the rice control falls below 72 ° C. at time t ₂ , this is detected and first, the energization control of the shoulder heat retention is started and the inner pot lid is overheated by heat conduction.
Next, when the rice temperature drops to 71 ° C or less, this is detected, and the side part of the inner pot is heated by radiant heat by controlling the energization of the body part heat retention heater to energize the heat retention heater and heat the rice Normal heat retention control is performed to keep the heat retention temperature in the jar at 71 ° C. While the normal heat retention control is being performed, the heat retention control is always performed so that the shoulder heat retention heater is maintained at a higher temperature than the body heat retention heater. When controlling the energization of these warming heaters, energization of the shoulder warming heater is always started earlier than the trunk warming heater, and at the same time, the shoulder warming heater causes heat conduction to the inner pot lid. Since it is overheated, it is more surely overheated and the heat retention control is performed.

As a result, the shoulder part of the inner pan storage container is a part near the opening and closing part of the lid part of the rice cooker body and outside air easily enters, but the shoulder heat insulation heater always energizes the heater so that the heat amount is higher than the surroundings. Control can be performed, and the heat retention control of the rice cooker is performed by preventing the heat retention temperature around the shoulder from lowering. The amount of heat generated from the shoulder heat retaining heater is conducted to the lid of the inner pot to prevent dew dripping. That is, the temperature change of the rice and lid during the heat retention control is
As shown in FIG. 5, the temperature of the lid portion of the inner pot is always kept higher than that of the inner pot to prevent dew drop from the lid. Next, an example of the control process of the heat retention process control will be described with reference to the flowchart of FIG.

When the cooking of rice is completed and the control of the rice cooking process is completed, the process proceeds to the heat retention process control. When the heat retention process control is started, first, in step 60, the heat retention LED (light emitting diode) is turned on to display that the operation has entered the heat retention operation mode, and in the next step 61, the rice cooking heater is turned off. . Next, at step 62, the data from the sensor is read to determine whether the temperature of the inner pot is 72 ° C. or lower. If the temperature is not below 72 ° C,
In step 63, the shoulder heat retaining heater is turned off, in step 64 the body temperature heater is turned off, the process returns to step 60, and the processing from step 60 is performed. Inner pot temperature is 7
The processing from step 60 to step 64 is repeated until the temperature falls below 2 ° C. Also, step 62
When it is determined that the temperature of the inner pot is 72 ° C. or lower in the determination process of step S65, the process proceeds to step 65, and it is further determined whether the temperature is 71 ° C. or lower. If the temperature is not lower than 71 ° C., that is, if the temperature is between 72 ° C. and 71 ° C., the process proceeds to step 66, the shoulder heat retaining heater is turned on in step 66, and the body heat retaining heater is turned off in the next step 67. Then, the process returns to step 60 and the processing from step 60 is repeated. If it is determined in step 65 that the temperature is 71 ° C. or lower, the process proceeds to step 68. In step 68, the shoulder heat retention heater is first turned on, and in the next step 69, the trunk heat retention heater is turned on. Turn on.
Then, the process returns to step 60, and the processing from step 60 is repeated. In this way, the temperature of the inner pot is detected and determined, the energization control of each heat retention heater is performed according to the temperature, and the heat retention control of the rice cooking heat retention jar is performed.

Since the heat retention process control is performed as described above,
The shoulder warmer heater is always energized earlier than the body warmer heater, and the shoulder warmer heater has a warmer temperature (72 ° C.) higher than the warmer temperature (71 ° C.) at which the body warmer heater is turned on. It is turned on at (℃), and the inner pot lid is further heated by heat conduction. As a result, the temperature around the shoulder heat retaining heater is always kept higher than the ambient temperature, and this high temperature is surely thermally conducted to the lid portion quickly to prevent the dew drop from the lid portion.

As a result, in the rice cooker jar, the heat generated from the heater is transmitted to the lid part of the rice cooker pot where the temperature drops quickly, not by heat radiation but by heat conduction. The heat from the heat retaining heater can be surely transferred to the lid of the inner pot quickly (by making the shoulder heat retaining heater generate a higher heat retaining temperature), and the heater energization of the heat retaining control of the first heat retaining heater is maintained by the second heat retaining heater. Coupled with the fact that the energization starts earlier than the heater energization for control,
The lid part of the inner pan can be heated to a higher temperature surely faster than the side part of the inner pan, and the warming operation can be performed, and the dew drop from the lid part is prevented during the warming operation. In addition, by raising the heat retention temperature of the upper part of the rice cooker faster during heat retention operation, the heat retention temperature of the lower part of the rice cooker is maintained without increasing it, preventing evaporation of water from the rice and causing so-called rice discoloration. Prevent browning.

Therefore, according to this rice heat insulation jar, when the user uses the rice from the rice heat insulation jar when the rice is cooked and is in a heat retaining state, there is no dew drop and the usability is improved and the browning of the rice is prevented. It can be prevented.

In the case of performing such warming control that prevents the dew drop, it is necessary to provide a warming heater on the shoulder and to provide warming control means for controlling the warming heater of the shoulder, but perform rice cooking control by microcomputer control. In this case, since the control function of the microcomputer can be used as it is for the energization control of the heat retention heater on the shoulder, it is possible to add the heat retention temperature program to the program for rice cooking control without adding special hardware. Well, there is no cost increase. As a result, a rice cooker that does not drop dew even when used can be provided without increasing the cost.

The present invention has been specifically described above based on the embodiments,
It is needless to say that the present invention is not limited to the above-mentioned embodiment, and various modifications can be made without departing from the spirit of the present invention.

[Effects of the Invention] As described above, according to the present invention, in the rice cooker, when the user uses the rice from the rice cooker when the cooked rice is in the heat-retaining state, the dew drop is applied. There is no problem, the usability is improved, and a rice cooker that can prevent browning of rice is provided.

[Brief description of drawings]

FIG. 1 is a partially cutaway sectional view of a rice cooker jar according to an embodiment of the present invention, FIG. 2 is a front view showing a panel surface of a function selection operation unit, and FIG. 3 is a microcomputer. FIG. 4 is a block diagram showing the configuration of the main part of the control unit, FIG. 4 is a flow chart showing the outline of the overall control flow of the microcomputer, and FIG. 5 is the rice temperature and lid in the heat retention mode for explaining the heat retention control. The figure which shows the temperature change of temperature, FIG. 6 is a flowchart which shows the processing flow of freshly cooked heat retention control. In the figure, 1 ... Rice cooker main body, 2 ... Lid part, 3 ... Main body part, 4 ... Inner pan lid, 4a ... Inner pan lid, 5 ... Inner pan storage container, 6 ... Rice heating heater, 7 ... Temperature sensor, 8 ... Shoulder Part heat-retaining heater, 9 ... Body heat-retaining heater, 10 ... Control unit, 11 ... Function display selection operation unit, 12 ... Character display, 13 ... Operation key switch, 14 ...
Status display, 15 ... Commercial AC power supply, 16 ... Thermal fuse, 17
… Relays, 18,19a, 19b… Triacs, 20… Microcomputers, 21… Clock mechanism.

Claims (1)

[Claims] 1. A rice cooker body composed of a main body having a lid and an inner pot storage container, a rice cooker heater provided at the bottom of the inner pot to be stored in the inner pot storage container, and a shoulder portion of the inner pot storage container. The 1st heat retention heater provided and the 2nd provided on the body of the inner pot storage container
What is claimed is: 1. A rice cooking heat retention jar having a warming heater and control means for controlling the heating process and controlling the heating process by energizing each heater, wherein the control means performs the heating process control after performing the cooking process control. In the heater control of the control, the lid of the inner pot is heated by heat conduction from the first heat retaining heater of the shoulder portion, and the side portion of the inner pot is heated by radiant heat from the second heat retaining heater of the body portion. The warming control temperature of the warming heater is set higher than the warming control temperature of the second warming heater, and the heater energization for the warming control of the first warming heater is performed earlier than the heater powering for the second warming heater. A rice heating jar characterized by turning on electricity.