JP2013255543A - Rice cooker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve such problems that deterioration of rice such as yellowing and drying of rice is promoted, which leads to decrease in a heat insulation performance, if estimated temperature conditions are not met, when the heat insulation temperature is controlled with the same DUTY without any relation to room temperature at a high temperature heat insulation temperature control (for instance, 72°C or 74°C temperature control).SOLUTION: A rice cooker is composed to presume an actual room temperature based on a threshold preset by using temperature data recorded by a room temperature recording means at the start of rice cooking or a room temperature recording means during heat insulation upon high temperature insulation, and control a heating means by the input from a voltage fluctuation detecting means, so as not to be influenced by the fluctuation of the atmospheric temperature and a power source voltage. The rice cooker performs an optimal heat insulation temperature control, that is, control with larger DUTY when the room temperature is low, and with fewer DUTY when the room temperature is high, which enables more optimal heat insulation corresponding the a quantity of cooked rice without depending on the room temperature, prevention of the deterioration of rice such as yellowing and drying of rice, and improvement in the heat insulation performance.

Description

  The present invention relates to a rice cooker.

  Conventionally, in order to pursue the deliciousness of rice, this type of rice cooker has continuously evolved so that the cooked rice and the heat-retaining state are stable (for example, see Patent Document 1).

JP 2003-339525 A

  However, when the rice is kept warm by the above-described conventional rice cooker warming sequence, especially at high temperature warming temperature control (for example, 72 ° C or 74 ° C temperature control), the heat is kept at the same DUTY regardless of the room temperature. When temperature control is performed, temperature control is controlled by DUTY determined under low temperature and low voltage conditions (worst lower limit conditions assumed for ambient temperature and power supply voltage), so high temperature and high voltage (atmosphere temperature and power supply voltage and (The worst upper limit condition assumed in (1)) promotes the deterioration of the rice such as yellowing and drying of the rice, leading to a decrease in heat insulation performance. In addition, there is a problem that the amount of power consumption increases due to excessive heating.

  This invention solves the said conventional subject, and it aims at providing the rice cooker which prevented deterioration of rice, such as yellowing of rice and drying, and aimed at the improvement of heat retention performance.

  In order to solve the above-mentioned conventional problems, the rice cooker of the present invention includes a rice pot and a water pot detachably stored in the rice cooker body, a heating means for heating the pot, and the temperature in the pot or pan. Pan temperature detecting means for detecting the room temperature, room temperature detecting means for detecting the room temperature, rice cooking start room temperature recording means for recording the room temperature detected by the room temperature detecting means at the start of cooking, room temperature, at a predetermined time, at room temperature A control means comprising: a room temperature recording means for recording the room temperature detected by the detection means; a voltage fluctuation detection means for detecting a power supply voltage fluctuation; and a control means for controlling the heating means at the time of cooking and during the heat retention after the completion of rice cooking. When the temperature is kept warm, the actual room temperature is estimated based on a preset threshold value using the temperature data recorded by the cooking room temperature recording means or the warming room temperature recording means, and input from the voltage fluctuation detection means By It is obtained by the configuration for controlling the heat means.

  Thereby, since the temperature control DUTY at the time of high temperature heat insulation can be set for each room temperature, it is possible to provide a rice cooker that can perform optimum heat insulation regardless of the room temperature.

  The rice cooker of this invention can perform the more optimal heat retention according to the amount of rice cooking irrespective of room temperature and a voltage. As a result, it is possible to provide a rice cooker that prevents deterioration of the rice, such as yellowing and drying of the rice, and achieves improved heat retention performance.

Sectional drawing of the rice cooker in Embodiment 1-7 of this invention The block diagram of the rice cooker in Embodiment 1-7 of this invention The temperature chart which showed the relationship between the heat retention elapsed time of the rice cooker and pan temperature sensor detection temperature in Embodiment 1 of this invention

  1st invention is the pan which puts the rice and water detachably accommodated in the rice cooker main body, the heating means which heats a pan, the pan temperature detection means which detects the temperature in a pan or a pan, and room temperature Room temperature detection means for detecting the temperature, rice cooking start room temperature recording means for recording the room temperature detected by the room temperature detection means, and during the heat retention, when the predetermined time elapses, the room temperature detection means for recording the room temperature detected by the room temperature detection means Room temperature recording means, voltage fluctuation detection means for detecting power supply voltage fluctuation, and control means for controlling the heating means at the time of cooking and at the time of heat retention after the completion of rice cooking, the control means records the room temperature at the start of rice cooking at high temperature heat insulation This means that the actual room temperature is estimated based on a preset threshold value using temperature data recorded by the room temperature recording means, and the heating means is controlled by input from the voltage fluctuation detection means. Ah .

  As a result, even when room temperature fluctuations or power supply voltage fluctuations occur, the temperature adjustment DUTY during high temperature insulation can be set for each room temperature. In other words, the heating means can be controlled with a large DUTY when the room temperature and voltage are low, and with a small DUTY when the room temperature is high and the voltage is high. Temperature control, that is, control with a large DUTY when the room temperature is low and the voltage is low, and control with a small DUTY when the room temperature is high and the voltage is high. It is possible to prevent the deterioration of the rice such as yellowing and drying of the rice and improve the heat retaining performance.

  In a second aspect of the invention, in particular, in the first aspect of the invention, the predetermined time is a time during which the temperature in the pot or the pot is stabilized during the low-temperature temperature adjustment during the heat retention.

  As a result, even if it is room temperature data obtained by inferring heat retention control in the high-temperature temperature control process, it is not significantly different from the actual measurement value, and it is affected by changes in the environment because it is stable data during heat insulation. In addition, since the data used is stable temperature data, accurate control can be performed.

  The third invention uses the temperature data at the time of low temperature heat stabilization before the temperature rise, particularly in the first or second invention, when there is a temperature raising step during the temperature keeping.

  As a result, even if there is a temperature raising process at the time of heat retention, the temperature data at the time of stabilization before the temperature rise is used for the high temperature heat insulation control after the temperature raising process, so the adopted data is stable temperature data. Therefore, accurate control can be performed.

  In the fourth invention, in particular, in any one of the first to third inventions, when the temperature raising step is performed a plurality of times during the heat retention, the temperature data at the time of the low temperature heat retention before the final temperature rise is used. It is what.

  As a result, even if the room temperature data obtained by estimating the temperature control in the temperature control section is not significantly different from the measured value, it is the data immediately before the temperature control that performs the high temperature temperature control, so the change in the environment Since it is not affected and the data used is the latest stable temperature data, more accurate control can be performed.

  5th invention, especially in any one of 1st-4th invention, when it has two temperature data recorded by the room temperature recording means at the time of rice cooking, and the room temperature recording means at the time of heat retention, it records by the room temperature recording means at the time of heat insulation The temperature data is used.

  As a result, even if it is room temperature data obtained by inferring heat retention control in the temperature control section, it is not significantly different from the actual measured value, and it is affected by changes in the environment because it is data immediately before heat insulation, not during cooking. In addition, since the data to be used is stable temperature data, the high-temperature temperature control based on the recorded room temperature can be performed more accurately.

  6th invention, especially in any one of 1st-4th invention, when it has only the temperature data recorded by the room temperature recording means at the time of rice cooking, when using the temperature data recorded by the room temperature recording means at the time of rice cooking start It is what.

  Thereby, even when there is no temperature data during heat retention, temperature control can be performed based on the temperature data at the start of rice cooking, so that the influence of the room temperature can be suppressed as much as possible and optimal heat retention can be performed.

  The seventh aspect of the invention relates to the heating means in which, in particular, in any one of the first to fourth aspects of the invention, when both the temperature data recorded by the room temperature recording means at the start of rice cooking and the temperature data recorded by the warming room temperature recording means are not included, it is assumed that the temperature is low. Is supposed to be controlled.

  As a result, when there is no temperature data at the start of cooking or during warming, when the actual room temperature is low by controlling with DUTY based on the temperature data at low temperature, that is, with a large DUTY In addition, it is possible to prevent spoilage due to insufficient heating of the rice being kept warm, and to perform optimum heat keeping control.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
1 is a cross-sectional view of a rice cooker in the first embodiment of the present invention, FIG. 2 is a block diagram of the rice cooker in the first embodiment of the present invention, and FIG. 3 is in the first embodiment of the present invention. The temperature chart which showed the relationship between the heat retention elapsed time of a rice cooker, and pan temperature sensor detection temperature is shown.

  1 and 2, the rice cooker body 1 of the rice cooker according to the present embodiment is formed of a magnetic material such as stainless steel or iron, and detachably houses a pan 2 for putting rice and water therein. Yes. The upper opening 2a of the pan 2 is covered with an outer lid 5 so as to be freely opened and closed.

  A heating coil 3 as a heating means for heating the pan 2 is disposed outside the bottom surface of the pan 2 and generates an alternating magnetic field by a high-frequency current supplied from a high-frequency power source (not shown). The induction heating.

  A ferrite (not shown) made of a highly permeable magnetic material is disposed near the outside of the heating coil 3 so that the winding direction of the heating coil 3 is substantially perpendicular to the winding direction. The ferrite prevents the magnetic field generated by the heating coil 3 from leaking to the outside of the rice cooker body 1 and promotes induction heating to the pan 2.

  In the present embodiment, the case where the heating method for the pot 2 is based on induction heating is described, but the effect of the present invention is not changed even if the heating method for the pot 2 is based on a sheathed heater.

  The pan temperature sensor 6 as a pan temperature detecting means detects the temperature of the pan 2 and is composed of a thermistor (not shown), and detects the temperature of the pan 2 by its resistance value.

  The room temperature sensor 30 as a room temperature detection means detects the temperature outside the rice cooker body 1 of the rice cooker, that is, the room temperature, and is composed of a thermistor (not shown), and detects the room temperature by its resistance value. ing.

  The rice cooking start room temperature recording means 31 records the temperature input value from the room temperature sensor 30 when the operation unit 22 receives the rice cooking start switch 21.

  Also, the room temperature recording means 32 at the time of heat retention is supplied from the room temperature sensor 30 when a predetermined time has elapsed (for example, when 3 hours have elapsed since the start of heat retention) during the heat retention process in the heat retention sequence stored in advance in the control means 11. The temperature input value is recorded.

  The control board 7 includes a control unit 11 and a power supply unit 12. The control unit 11 includes an output from the pan temperature sensor 6, an output from the room temperature sensor 30, a rice cooking start switch 21, and a heat retention start switch 24. , An input signal from the menu selection means 4, a room temperature recording means 31 at the start of rice cooking, a room temperature recording means 32 at the time of warming, and an input signal from the voltage fluctuation detection means 33 are input.

  The control board 7 supplies a high-frequency current to the heating coil 3 by switching a semiconductor power element such as an IGBT provided between the high-frequency power source (not shown) constituting the power supply means 12 and the heating coil 3. The supply power can be controlled by the switching frequency, the heating amount of the heating coil 3 is controlled, the pan 2 is heated, and rice and water in the pan 2 are cooked.

  When the heating method of the pan 2 is a sheathed heater, the control means 11 and the power supply means 12 heat the pot 2 by energizing the sheathed heater by switching a relay or the like provided between the sheathed heater and the inside of the pot 2 Configure to cook rice and water.

  Moreover, the notification means (not shown) comprised with the buzzer is provided, and when the rice cooking start switch 21 or the heat retention start switch 24 is received in the operation part 22, it rings at the end of rice cooking.

  Operation | movement and an effect | action of the rice cooker in this Embodiment comprised as mentioned above are demonstrated.

  After completion of rice cooking or when a heat retention start switch 24 is received, a heat retention and temperature adjustment operation is performed based on a heat retention sequence stored in advance in the control means 11. In the heat insulation temperature control operation based on the heat insulation sequence, especially at the time of high temperature insulation (for example, 74 ° C. heat insulation temperature control), in the heat insulation sequence equipped with the conventional rice cooker, the heat insulation control is performed with a fixed DUTY value that is independent of the room temperature. .

  This fixed DUTY value is used in order to prevent the spoilage of the rice during the heat insulation, so that the temperature is low (for example, −5 ° C.) and the voltage is low (for example, 90 V) Since it was determined assuming the worst lower limit condition), the actual use environment was high temperature (for example, 35 ° C.) and high voltage (for example, 110 V) under the normal environment assumed by the ambient temperature and the power supply voltage (for example, 110 V). The worst upper limit condition), the rice was yellowed and burned due to excessive heating.

  In the rice cooker of the present embodiment, a low temperature (−5 ° C. in the present embodiment), a medium temperature (25 ° C. in the present embodiment), and a high temperature (35 ° C. in the present embodiment). Since the DUTY value corresponding to each voltage (in this embodiment, 90V, 95V, 100V, 105V, 110V) is recorded in advance in the control means 11 under each condition, the room temperature at the start of cooking is high temperature The DUTY value can be selected according to the input results from the recording means 31, the room temperature recording means 32 during warming, or the voltage fluctuation detection means 33.

  When the actual room temperature is estimated on the basis of a predetermined threshold value, 33 ° C. of the temperature recorded in the rice cooking start room temperature recording unit 31 or the warming room temperature recording unit 32 is set in the low temperature region. The threshold temperature of 42 ° C. is made correspond to the threshold temperature of the high temperature region, a temperature lower than 33 ° C. is estimated as a low temperature, a temperature of 33 ° C. or higher and lower than 42 ° C. is estimated as a medium temperature, and a temperature higher than 42 ° C. is set as a high temperature. As a result of the estimation, the temperature control can be performed by the optimum DUTY suitable for the external environment including the fluctuation of the power supply voltage, and the heat insulation performance can be improved.

  As described above, according to the present embodiment, by recording the room temperature at the start of rice cooking or at the time of heat retention, the temperature is maintained by optimum DUTY control that matches the room temperature without being affected by fluctuations in the ambient temperature or power supply voltage. As shown in FIG. 3, the pan temperature can be maintained, and the deterioration of the rice such as rotting, yellowing, and drying of the rice can be prevented, and the heat retention performance can be improved.

  In the present embodiment, the predetermined temperature threshold when determining the DUTY value is shared by the rice cooking start room temperature recording unit 31 and the warming room temperature recording unit 32, but depending on the installation location of the room temperature sensor, Because the temperature of the heater at the time of starting rice cooking is different from that at the time of adjusting the heater temperature at the time of stable heating, the temperature recorded in the room temperature recording means 31 at the start of cooking and the temperature recorded in the room temperature recording means 32 at the time of heating are independent. The estimated temperature may be retained.

  In the present embodiment, the DUTY value at the time of high-temperature temperature adjustment can be selected according to the input result from the room temperature recording means 32 during the heat retention. However, if there is room in the heat retention sequence recording memory of the control means 11 For example, it may be possible to select from a storage memory of a heat retention sequence for each capacity of the rice cooker (for example, 10 go cooking, 5.5 go cooking).

  In the present embodiment, only the DUTY value at the time of high-temperature temperature adjustment can be selected according to the input result from the room temperature recording means 32 at the time of heat retention. If there is a margin in the recording memory of the sequence, the DUTY value in a process other than the high-temperature temperature control may be selected according to the input result from the room temperature recording means 32 during the warming.

(Embodiment 2)
The rice cooker in Embodiment 2 of this invention is demonstrated using FIG. 1, FIG. In the present embodiment, the difference from the first embodiment is that the predetermined time is set to a time (for example, 5 hours) during which the temperature in the pot or the pot is stabilized during the low-temperature temperature adjustment during the heat retention.

  With such a configuration, even if it is room temperature data obtained by inferring heat retention control in the temperature control section, it is not significantly different from the actual measurement value, and since it is data during heat retention, it may be affected by environmental changes. In addition, since the data to be used is stable temperature data, accurate control can be performed.

(Embodiment 3)
The rice cooker in Embodiment 3 of this invention is demonstrated using FIG. 1, FIG. In this embodiment, the difference from Embodiments 1 and 2 is that temperature data at the time of low-temperature heat retention stability before temperature increase is used.

  With such a configuration, even if there is a temperature raising process during the heat retention, the temperature data at the time of stable temperature rise is used for the high temperature heat insulation control after the temperature raising process, so accurate control without malfunction It can be performed.

(Embodiment 4)
The rice cooker in Embodiment 4 of this invention is demonstrated using FIG. 1, FIG. In the present embodiment, the difference from the third embodiment is that, when the temperature raising process is performed a plurality of times during the temperature keeping, the temperature data at the time of the low temperature keeping stability before the final temperature raising is used.

  With such a configuration, even if the room temperature data obtained by inferring the heat retention control in the temperature control section is not significantly different from the actual measurement value, it is the data immediately before the heat retention that performs the high temperature heat insulation temperature control, so the environment Since the data used is stable temperature data, accurate control can be performed.

(Embodiment 5)
The rice cooker in Embodiment 5 of this invention is demonstrated using FIG. 1, FIG. In the present embodiment, the difference from the first embodiment is that, when there are two temperature data recorded by the room temperature recording means 31 at the start of rice cooking and the room temperature recording means 32 during the heat retention, the temperature data recorded by the room temperature recording means 32 during the heat retention. Is to use.

  With such a configuration, even if it is room temperature data obtained by inferring heat retention control in the temperature control section, it does not differ greatly from the actual measurement value, but it is data immediately before the heat retention, not during cooking, so the environmental change Since the data used is stable temperature data, high-temperature temperature control based on the recorded room temperature can be performed more accurately.

(Embodiment 6)
The rice cooker in Embodiment 6 of this invention is demonstrated using FIG. 1, FIG. In this embodiment, the difference from the fifth embodiment is that when only the temperature data recorded by the room temperature recording means 31 at the start of rice cooking is used, the temperature data recorded by the room temperature recording means 31 at the start of rice cooking is used. .

  With such a configuration, even when there is no temperature data during heat retention, temperature control can be performed based on the temperature data at the start of rice cooking, so that it is possible to perform optimum heat insulation without being affected by the room temperature.

(Embodiment 7)
The rice cooker in Embodiment 7 of this invention is demonstrated using FIG. 1, FIG. In the present embodiment, the difference from the sixth embodiment is that when both the temperature data recorded by the room temperature recording means 31 at the start of rice cooking and the temperature recording means 32 at the time of heat retention are not included, the heating means is controlled on the assumption that the temperature is low. That is.

  With such a configuration, even when there is no temperature data at the start of rice cooking or during warming, the actual room temperature can be determined by controlling with DUTY based on the temperature data at low temperature, that is, with a large DUTY. When the temperature is low, rotting due to insufficient heating of the rice being kept warm can be prevented, and optimum heat keeping control can be performed.

  As mentioned above, since the rice cooker concerning this invention can perform the more suitable heat retention according to the amount of rice cooking irrespective of room temperature and a power supply voltage fluctuation | variation, the heat retention in an overheating state can be reduced. As a result, it is useful as a rice cooker because the deterioration of the rice such as yellowing and drying of the rice can be prevented and the heat retention performance can be improved.

DESCRIPTION OF SYMBOLS 1 Rice cooker main body 2a Upper opening part 2 Pan 3 Heating coil (heating means)
4 Menu selection means 5 Outer lid 6 Pan temperature sensor (pan temperature detection means)
7 control board 11 control means 12 power supply means 21 rice cooking start switch 22 operation part (operation means)
24 Thermal insulation start switch 30 Room temperature sensor (room temperature detection means)
31 Room temperature recording means at the start of rice cooking 32 Room temperature recording means during warming 33 Voltage fluctuation detection means

Claims (7)

A pan for rice and water detachably stored in the rice cooker body, a heating means for heating the pan, a pan temperature detecting means for detecting the temperature in the pan or the pan, and a room temperature detecting means for detecting the room temperature A rice cooking start room temperature recording means for recording the room temperature detected by the room temperature detection means at the start of cooking, a warming room temperature recording means for recording the room temperature detected by the room temperature detection means when a predetermined time has elapsed during heat insulation, and a power source A voltage fluctuation detecting means for detecting voltage fluctuation and a control means for controlling the heating means at the time of cooking and at the time of heat retention after the completion of rice cooking, the control means at the time of high temperature heat retention, at the time of rice cooking start room temperature recording means, or at the time of heat retention A rice cooker configured to estimate the actual room temperature based on a preset threshold value using temperature data recorded by the room temperature recording means, and to control the heating means by an input from the voltage fluctuation detection means. The rice cooker according to claim 1, wherein the predetermined time is a time during which the temperature in the pot or the pot is stabilized during the low-temperature temperature adjustment during the heat retention. 3. The rice cooker according to claim 1, wherein when there is a temperature raising process at the time of heat insulation, temperature data at a low temperature heat insulation stability before temperature rise is used. The rice cooker according to any one of claims 1 to 3, wherein when the temperature raising step is performed a plurality of times at the time of heat retention, temperature data at the time of low temperature heat retention stability before the final temperature rise is used. The rice cooking according to any one of claims 1 to 4, wherein when two temperature data recorded by the room temperature recording means at the start of rice cooking and the room temperature recording means at the time of keeping warm are used, the temperature data recorded by the room temperature recording means at the time of keeping warm is used. vessel. The rice cooker of any one of Claims 1-4 which uses the temperature data recorded by the room temperature recording means at the time of rice cooking start, when it has only the temperature data recorded by the room temperature recording means at the time of rice cooking start. The rice cooker according to any one of claims 1 to 4, wherein when the temperature data recorded by the room temperature recording means at the start of rice cooking and the temperature recording means at the time of keeping warm are not included, the heating means is controlled assuming that the temperature is low.

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