JP3709844B2 - rice cooker - Google Patents

Description

[0001]
[Technical field to which the invention belongs]
The present invention relates to a rice cooker that employs an electromagnetic induction heating method, and in particular, obtains room temperature data and abnormal temperature data with a single sensor provided on a substrate, and uses these data to perform rice cooking and heat retention control. It is about.
[0002]
[Prior art]
Recently, the demand for rice cookers has increased, and many functions have been added to rice cookers. For example, electromagnetic induction heating using a work coil as a heating means has been adopted. Rice cookers have come to be widely used as one of the easy-to-use products, such as being able to appropriately perform control and heat retention control over a long period of time thereafter.
[0003]
As described above, in the rice cooker, when rice cooking control by electromagnetic induction heating using a work coil and subsequent heat retention control are performed, not only safety but also more precise heating control is required. As a result, many parts are used, which is also a factor in raising product prices. For this reason, not only a reduction in manufacturing cost but also a measure to reduce the total production cost by reducing the number of parts even if only one screw is considered.
[0004]
FIG. 10 shows a conventional rice cooker. If the outline is demonstrated, the outline of the rice cooker a consists of the container main body b which forms a trunk | drum, and the cover part c which is located in the upper part of the container main body b and can be attached or detached to the container main body b. The container body b includes an inner case d disposed on the inner side, an outer case e that forms an outer shell, and a bottom case f that forms a bottom. A work coil h, which is a main component of electromagnetic induction heating, is disposed at the bottom of the inner case d, and an inner pot g for storing rice or the like is accommodated in the inner case d. In addition, an inner pot sensor i for detecting the temperature of the inner pot g necessary for performing heating control is provided at the bottom center of the inner case d.
[0005]
A space j is formed in front of the rice cooker a. In the front space j, an operation board k to which a display unit, various switch buttons, and the like are attached, and heating control of an IGBT, a diode bridge, and the like are performed. A control board m to which various necessary electronic control elements are attached is provided, and precise heating control of the rice cooker a is performed by the action of these various electronic control elements.
[0006]
By the way, the heating control of the rice cooker a is provided with a safety device that cuts off the circuit system when the heating temperature is abnormally increased so that the heating does not become abnormal, and a temperature sensor that detects this abnormal temperature. This temperature sensor is shown as r in FIG. Since the abnormal temperature at the time of heating can be almost identical to the abnormal temperature of the control board m, the temperature sensor r is provided on the control board m, and the abnormality of the heating control is determined by detecting the temperature of the control board m. .
[0007]
In addition, in order to precisely control the heating of the rice cooker a, it is necessary to know room temperature data, and a temperature sensor for that purpose is required. As described above, the temperature sensor r is used for the control board m in order to detect an abnormal temperature of the control board m. However, since the temperature sensor r is provided on the control board m, the initial temperature is measured. However, if it is attempted to capture room temperature data again during the heat insulation process, the temperature sensor r is warmed to a considerable temperature, so that accurate room temperature data cannot be captured. It was necessary to install it in an unaffected part.
[0008]
For this reason, as shown in FIG. 10, a room temperature sensor q, which is a separate temperature sensor, is provided on the operation board k. The reason why it is provided at this location is because it is far from the control board m.
[0009]
However, the use of two temperature sensors in this way naturally leads to an increase in cost, and the following problems also occur. That is, since the room temperature sensor q is provided on the operation board k that is distant from the control board m, the room temperature sensor q is hardly affected by the temperature of the heating element provided on the control board m. The forward space j is a substantially sealed space, and communicates with the outside air through an air inlet p provided at the lower part of the cooling fan n. For this reason, the atmosphere around the room temperature sensor q is unlikely to interact with the outside air, and there is no problem if it is used as room temperature data in the initial stage of cooking rice. It was warmed by the influence of the temperature at the time of cooking rice or keeping warm, and it was not very room temperature data, and could not be reflected in accurate heating control.
[0010]
[Problems to be solved by the invention]
The object of the present invention is to make the temperature sensor one on the control board, and to measure the room temperature at the start of cooking rice or at the start of heat retention, the cooling fan drives the cooling fan and takes in the temperature sensor from the intake port to the outside air temperature. An object of the present invention is to provide an induction heating rice cooker that can reduce the production cost and can perform proper heating control by measuring the room temperature after cooling to substantially the same temperature.
[0011]
[Means for Solving the Problems]
In order to achieve the above object, the present invention adopts the following configuration.
[0012]
In the invention according to claim 1, an inner case that can accommodate the inner pot and forms an inner wall, a container body that forms an outer wall, a lid member that can be opened and closed with respect to the container body, a heat retaining heater, and electromagnetic induction heating A heating means for performing, a substrate on which various electronic control elements including a heat generating component for controlling the heating means are mounted, an inner pot sensor for detecting the temperature of the inner pot, and a cooling fan for cooling the heat generating component; In the rice cooker provided with a sensor, a sensor is provided in the vicinity of the heat generating component, and at least room temperature and an abnormal temperature of the heat generating component are measured by the sensor, and the measurement data is used for heating control in the rice cooking process and / or the heat retaining process. In addition, during the heat retaining process following the rice cooking process, the output of the heat retaining heater is changed in accordance with the initial room temperature data already measured by the sensor, and the inner pot regardless of the room temperature. Changing the output of said heating means in accordance with the heat retaining temperature measured by capacitors, the initial room temperature data, Oh at room temperature data before heating during cooking process is carried out The room temperature data after driving the cooling fan Configuration.
[0013]
In the invention which concerns on Claim 2, the inner case which can accommodate an inner pot and forms an inner wall, the container main body which forms an outer wall, the lid member which can be opened and closed with respect to this container main body, and the heating means for performing electromagnetic induction heating A rice cooker comprising: a substrate on which various electronic control elements including a heat generating component for controlling the heating means are mounted; an inner pot sensor for detecting the temperature of the inner pot; and a cooling fan for cooling the heat generating component. In the cooker, a sensor is provided in the vicinity of the heat generating component, and at least the room temperature and the abnormal temperature of the heat generating component are measured by the sensor, and the measurement data is used for heating control in the rice cooking process and / or the heat retaining process, and the rice cooking process At the start of the measurement, the sensor measurement data is used as room temperature data for controlling the heating amount, and during the rice cooking process, it is used as abnormal temperature data. F, and at the initial stage of the warming step, the initial room temperature data already measured by the sensor is used, and at the subsequent warming time, the room temperature at the subsequent warming measured by the sensor is used. Is room temperature data before heating during the rice cooking process The room temperature data after driving the cooling fan Configuration.
[0014]
And by such a structure, since one temperature sensor can measure room temperature and the abnormal temperature in rice cooking, it becomes cheap. In addition, the temperature in the vicinity of the substrate at the start of rice cooking and heat retention varies greatly depending on whether it was in the previous state, for example, whether it was cooking rice, was warming, or was waiting. Therefore, more accurate room temperature can be measured, and rice cooking control and heat retention control are improved. Furthermore, it is possible to quickly cope with an abnormality in the temperature near the substrate during rice cooking, and there is no inconvenience of blowing the current fuse or turning off the breaker.
[0015]
Claim 3 In the invention according to the present invention, an inner case capable of storing an inner pot and forming an inner wall, a container body forming an outer wall, a lid member that can be opened and closed with respect to the container body, a heating means for performing electromagnetic induction heating, In a rice cooker comprising a substrate on which various electronic control elements including heating parts for controlling heating means are mounted, an inner pot sensor for detecting the temperature of the inner pot, and a cooling fan for cooling the heating parts, A sensor is provided in the vicinity of the heat-generating component, and at least the room temperature and the abnormal temperature of the heat-generating component are measured by the sensor, and the measurement data is used for heating control in the rice cooking process and / or the heat-retaining process. Alternatively, when a predetermined temperature lower than the heat retention temperature is detected, it is determined that the heat retention has ended, and the cooling fan is turned on.
[0016]
And by such a structure, since one temperature sensor can measure room temperature and the abnormal temperature in rice cooking, it becomes cheap. In addition, the temperature in the vicinity of the substrate at the start of rice cooking and heat retention varies greatly depending on whether it was in the previous state, for example, whether it was cooking rice, was warming, or was waiting. Therefore, more accurate room temperature can be measured, and rice cooking control and heat retention control are improved. Furthermore, it is possible to quickly cope with an abnormality in the temperature near the substrate during rice cooking, and there is no inconvenience of blowing the current fuse or turning off the breaker. Also, For example, even if the contents of the pan are replaced at the time of warming and the rice cooking is newly started, since the temperature sensor is adjusted to the room temperature, the temperature is measured, so that the room temperature can be measured more accurately and the temperature keeping control is improved.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1: shows sectional drawing which applied this invention to the rice cooker. As shown in FIG. 1, the rice cooker 1 is roughly divided into a container main body 2 that can accommodate the inner pot 10 therein, and a lid portion 3 that can freely open and close the upper opening of the container main body 2. The lid 3 is made of resin and includes an upper lid 31, a lower lid 32, a heat radiating plate 33, and an inner cover 35. A heat insulating material 36 is interposed in the internal space formed between the upper lid 31 and the lower lid 32. A lid heater 34 is disposed on the upper surface of the heat radiating plate 33, the heat radiating plate 33 is heated by the lid heater 34, and the rice in the inner pot 10 is heated from above and condensed on the inner surface of the heat radiating plate 33. Evaporates condensed water to prevent white blur of rice. The lid heater 34 is used in the rice cooking process and the heat retaining process.
[0018]
A pressure regulating lid 37 is provided at the center of the lid 3, and a valve member (not shown) is provided therein. When the internal pressure of the inner pot 10 rises above a predetermined level, the internal steam is regulated. It is discharged to the outside through a steam port 39 through a steam passage 38 formed in the lid 37. Further, on the rear side of the lid portion 3, a hinge mechanism 3 a that already contains a known spring material is provided, and the lid portion 3 is attached by the locking or unlocking action of the lock member 3 b provided on the upper front side of the rice cooker 1. The container body 2 can be opened and closed freely.
[0019]
The container body 2 includes an outer case 4 that forms an outer wall, an inner case 5 that is in the outer case 4 and forms an inner wall, shoulder members 6 that form upper ends of the inner and outer cases 4 and 5, and the rice cooker 1. It consists of a bottom case 8 that forms the bottom. Although these show what is formed separately, in order to reduce production cost, the inner case 5 and the shoulder member 6 can also be formed integrally.
[0020]
The outer case 4 is made of a metal such as stainless steel and has a cylindrical shape with upper and lower openings, and forms a body portion of the rice cooker 1. The upper and lower ends of the outer case 4 are recessed in a form in which a step is provided inward, that is, a form comprising a horizontal part 4a and a vertical part 4b. At the upper end portion of the outer case 4, the horizontal portion 4 a is in contact with the lower end portion of the shoulder member 6, and the vertical portion 4 b is positioned at the lower end side wall portion of the shoulder member 6. The horizontal part 4a abuts on the upper end part of the bottom case 8, and the vertical part 4b is positioned on the upper end side wall part of the bottom case 8, and the three members 4, 6, 8 are integrally connected by screws (not shown). .
[0021]
The shoulder member 6 is made of resin and forms an upper end portion of the container main body 2, and a hinge mechanism 3 a and a handle 7 are provided on the rear side inside and the outer peripheral side portion, respectively. When carrying the rice cooker 1, the handle 7 is rotated 90 degrees to the top, and is carried with the handle 7 at that position. After carrying, it is again rotated 90 degrees backward and stored in the position shown in the figure.
[0022]
The inner case 5 forming the inside of the container main body 2 has a W shape substantially the same shape as the inner pot 10. On the outer periphery of the inner case 5, a ring-shaped heat retaining heater 9 is attached with an aluminum sheet and stored inside. The inner pot 10 is kept warm from the side. The outer case 4 and the inner case 5 are firmly fixed to the shoulder member 6 by a forcible fitting means using a locking piece and a locking groove (not shown) and a screw (not shown).
[0023]
The bottom case 8 that forms the bottom of the rice cooker 1 is made of resin and is attached to the inner case 5 or the like with a screw (not shown), like the inner case 5. The bottom case 8 constitutes a bottom shell of the rice cooker 1, an intake port 8 a is provided in front of the bottom case 8, an exhaust port 8 b is provided in the rear thereof, and a plurality of legs 8 c are arranged on the bottom surface. Established.
[0024]
Reference numeral 10 denotes an inner pot housed in the inner case 5, which is made of iron, magnetic stainless steel, or the like made of a high magnetic material that increases eddy current induced inside, or is light in weight as a whole. Further, it is possible to use aluminum made of aluminum having a low skin resistance and formed by pressure-bonding magnetic stainless steel having a high skin resistance only on the bottom portion where the magnetic flux of the work coil hits or welding iron.
[0025]
The whole has a W-shaped cross section similar to that of the inner case 5, and when the inner pot 10 is stored in the inner case 5, a central bottom surface of the inner pot 10 is formed in the bottom center of the inner case 5. The top of the inner pot sensor 11 protruding through the mouth 5a is pressed. Then, the inner pot sensor 11 is pushed down to enable heating control of the rice cooker 1. That is, if the inner pot 10 is not stored in the inner case 5, the inner pot 10 and the inner pot sensor 11 serve as a safety device for the rice cooker 1 so that heating control is not performed. The inner pot sensor 11 includes a reed switch that detects the set state of the inner pot 10 and a thermistor that detects the temperature of the inner pot 10, and detects the temperature of the inner pot 10 with the thermistor to control rice cooking and keep warm. Take control. In addition, this inner pot sensor 11 may exist not in the lower center position of the inner pot 10, but the side part position of the inner pot 10, etc., for example.
[0026]
A bottom coil 12 and a corner coil 13, which are work coils, are disposed on the bottom and sides of the inner case 5, respectively. The bottom coil 12 and the corner coil 13 are fixed by a coil base (not shown). The bottom coil 12 and the corner coil 13 are formed by connecting a copper wire concentrically as many times as necessary and connecting it in series to a central portion and an outer peripheral portion. Reference numeral 14 denotes a cord winding box.
[0027]
A resin-made operation board holding member 16 is disposed in the front space 15 of the rice cooker 1. The operation board holding member 16 is provided with an operation board 17 to which various switch buttons 19 and a display unit 20 are attached in the vicinity of the operation panel 18. Further, a control board holding member 22 is fixedly disposed on the shoulder member 6 with a screw (not shown) in the vertical direction behind the operation board holding member 16. A control board 23 is attached to the control board holding member 22 with screws 24. Various electronic control elements 27 necessary for induction heating are attached to the control board 23. These various electronic control elements 27 include elements that generate heat, such as IGBTs (power transistors) and diode bridges, and the control board 23 includes a heat sink 26 for promoting the heat dissipation of these heat generation elements and the heat sink 26. A cooling fan 25 for cooling is attached by screws (not shown).
[0028]
A perspective view thereof is shown in FIG. A gate-shaped notch 23a is provided in the lower portion of the control board 23, and a heat sink 26 and a cooling fan 25 are inserted and disposed in the gate-shaped notch 23a so that the control board 23 is substantially in the center. The heat sink 26 is disposed on the control board 23 with a screw (not shown), and the cooling fan 25 is disposed below the heat sink 26 and attached to the heat sink 26 with a screw (not shown) from below.
[0029]
The cooling fan 25 is provided with a circular rotary blade 25b that is supported on a vertical axis in a rectangular fan case 25a. The rotary fan 25b rotates to rotate from an intake port 8a provided below the cooling fan 25. The air is sucked and sent to the heat sink 26 disposed on the upper portion thereof, and the heat sink 26 is efficiently cooled.
[0030]
The heat sink 26 is made of an aluminum material having a good heat dissipation effect and has a plurality of fins 26a. An upper opening 26b is provided on the upper surface, and a side opening 26c is provided on the side surface. Cooling air is supplied to the upper surface and side surfaces of the heat sink 26. The cooling air flows in the front-rear direction across the control board 23, the cooling air that flows forward further cools elements on the operation board 17, and the cooling air that flows backward further cools the bottom coil 12, the corner coil 13, and the like. And is discharged from the exhaust port 8b. The IGBT 27a and the diode bridge 27b, which are particularly heat generating elements, are directly attached to the upper surface of the heat sink 26 as shown in FIG.
[0031]
On the control board 23, a temperature sensor 28 which is a main part of the present invention is attached. The temperature sensor 28 is disposed in the vicinity of the side opening 26 c of the heat sink 26. Therefore, as shown in FIG. 2, the cooling air flowing out from the side opening 26c of the heat sink 26 as shown by the arrow hits the temperature sensor 28, and cools the temperature sensor 28 efficiently. This temperature sensor 28 is constituted by a diode type thermistor.
[0032]
Next, a control circuit for performing rice cooking control and heat retention control based on signals from the temperature sensor 28 and the inner pot sensor 11 will be described with reference to FIG.
[0033]
In the figure, reference numeral 40 is a microcomputer control unit (CPU) for rice cooking and heat retention control, and the CPU 40 is centered on a microcomputer, for example, an inner pot 10 portion or a temperature detection circuit section at room temperature, a work coil drive control circuit section, An oscillation circuit unit, a reset circuit unit, a drive control circuit unit such as a heat retaining heater and a shoulder heater, a power supply circuit unit, a display unit such as a liquid crystal display and an LED lamp, and an operation switch unit are provided.
[0034]
And first, the inner pot temperature signal by the inner pot sensor 11 is input to the inner pot temperature detection circuit 48 provided corresponding to the inner pot sensor 11 provided at the bottom of the inner pot 10, and further on the control board 23. A room temperature or abnormal temperature signal is input to the temperature detection circuit 49 by the temperature sensor 28 provided in the temperature detection circuit 49.
[0035]
The work coil drive control circuit unit is formed by, for example, a pulse width modulation circuit 46, a synchronization trigger circuit 53, an IGBT drive circuit 45, an IGBT 50, and a resonance capacitor 51. Then, by controlling the pulse width modulation circuit 46 by the CPU 40, for example, the output value of the bottom coil 12 and the corner coil 13 and the ON duty ratio at the same output value (for example, n seconds / 16 seconds) by appropriately changing the target heating temperature and heating pattern of the inner pot 10 in each step of rice cooking and heat retention, taking into account the amount of rice cooking, variably controlled, uniform water absorption action and no heating unevenness Appropriate heating output control for realizing cooking of rice and high-quality heat retention is performed.
[0036]
Reference numeral D denotes a flywheel diode of the IGBT 50, reference numeral 55 denotes a power supply side rectifier circuit incorporating a diode bridge for driving a work coil inserted between the household AC power supply 57, and reference numeral 52 denotes a smoothing circuit thereof.
[0037]
On the other hand, reference numeral 9 is the above-mentioned heat retaining heater, 34 is a lid heater, the heat retaining heater 9 is turned on and off at a desired output and duty ratio by a heat retaining heater driving circuit 56, and the lid heater 34 is turned on by a lid heater driving circuit 54, respectively. It is to be driven. Further, reference numeral 20 denotes a display unit such as a liquid crystal or LED, 43 denotes a notification unit such as a buzzer, 19 denotes various operation switch units such as a rice cooking switch, a heat retention switch, a timer switch, and a cancel switch, 47 denotes a clock reference control signal formation An oscillation circuit 44 is a reset circuit.
[0038]
Next, the contents of rice cooking and heat retention control of the rice cooker of the present invention, which is performed using the CPU 40 described above, will be described with reference to the time chart of FIG. 4 and the flowcharts of FIGS.
[0039]
First, the outline of the rice cooking process and the heat retaining process will be described according to the time chart of FIG. 4. In the rice cooking process, the water absorption for causing the rice to absorb water first by raising the outputs of the bottom coil 12 and the corner coil 13 to predetermined values. There is a process, and if enough water is absorbed into the rice, there is a temperature rising process that suddenly increases the output and cooks the rice at once, based on the temperature rising temperature per unit time in this temperature rising process The total number that is the amount of rice in the pan 10 is determined, and the temperature raising time in the subsequent temperature raising step is determined based on the total number of rice items. And the temperature rising process based on the determined temperature rising time is executed to cook rice. Then, the rice cooked in the uneven process is sufficiently uneven, and the rice cooking process is completed after making the rice ready for eating.
[0040]
In this case, when the rice cooking process is started, the cooling fan 25 is driven for 1 minute without heating from the work coil, the temperature sensor 28 is sufficiently cooled by the cooling air, and the temperature sensor 28 is set to the atmospheric temperature for 1 minute. Later, the temperature at that time is measured as an initial chamber temperature, and the data is stored in the CPU 40 and is called up and used in the subsequent temperature raising process.
[0041]
In addition, measurement by the temperature sensor 28 is performed in the water absorption process and the temperature raising process, and it is checked whether or not the temperature is abnormal. If the temperature is abnormal, the heating control is stopped to ensure safety. The reason is that the cooling fan 25 stops due to failure, the rice cooker 1 is cooked on a carpet with long hairs, and the intake port 8a is blocked by the carpet, so that sufficient cooling air is not supplied. Alternatively, when rice is cooked in a room having an abnormally high room temperature, the rice cooker 1 becomes dangerous, so that such danger is avoided.
[0042]
Also in the heat retaining process, the temperature sensor 28 is used to detect the room temperature, and the heat retaining control is performed based on the room temperature data. The heat retaining process may be performed following the rice cooking process or by pressing the heat retaining switch. First, when it is performed following the rice cooking process, even if it enters the heat retaining process, it is immediately after the rice cooking process and the temperature in the vicinity of the temperature sensor 28 is high. In this case, the room temperature data read at the start of the rice cooking process is used as it is because it does not readily drop to the atmospheric temperature.
[0043]
In the case where the heat retention process is further continued after 3 hours have passed, the temperature at that time is detected by the temperature sensor 28, the temperature is set to room temperature, and the subsequent heat retention control is continued. When the temperature sensor 28 periodically performs measurement in the subsequent heat retention control and the heat retention temperature falls below a predetermined value, the state of the inner pot 10 is detected again and it is determined that rice cooking will be performed anew. In this case, the cooling fan 25 is driven to cool the temperature sensor 28 and wait.
[0044]
Next, when the heat retention switch is pressed and the heat retention process is performed, the temperature in the vicinity of the temperature sensor 28 may be equal to or higher than room temperature, so the cooling fan is driven for 1 minute to cool the temperature sensor 28, and after cooling The room temperature is measured and used for subsequent heat control.
[0045]
Next, how the temperature sensor 28 is used in the rice cooking process and the heat retaining process will be described with reference to the flowcharts of FIGS.
[0046]
When the rice cooking switch is pressed, the state immediately before rice cooking can be in any state, for example, the previous rice cooking or the state immediately after warming, so the timer is activated for 1 minute in step S1, and the cooling fan 25 is driven in step S2. The cooling fan 25 is driven for 1 minute. The determination is made in step S3. If the cooling is less than 1 minute, the process returns to step S2 to continue driving the cooling fan 25.
[0047]
When the cooling is continued for 1 minute, the temperature sensor 28 is cooled and reaches the atmospheric temperature, so the room temperature is measured by the temperature sensor 28 in step S4, and the temperature data is stored in the CPU 40 as the initial room temperature. Thereafter, the timer is operated for 15 minutes in step S5, and the process proceeds to step S6 to start the water absorption process.
[0048]
The water absorption process is performed for 15 minutes, and the determination is performed in step S7. Therefore, when 15 minutes have elapsed, the process proceeds to step S11 and the heating process, which is also a cooking process, is performed. If it is less than 15 minutes, the process proceeds to step S8 and abnormal temperature detection is performed. The abnormal temperature detection is performed by the temperature sensor 28, and it is determined whether the temperature at that time is 70 ° C. or less. And if the temperature at that time is 70 degrees C or less, it will return to step S6 and a water absorption process will be continued, and if it is higher than 70 degrees C, it will progress to step S9 and electricity supply will be stopped, and while heating will be complete | finished, an error display will be carried out on the display part 20 at step S10 And cooking rice will be canceled.
[0049]
When 15 minutes have passed in step S7, the temperature raising process is started in step S11, and the process proceeds to step S12. If it is determined in step S12 that the temperature at that time is equal to or lower than the temperature rise temperature, the process proceeds to step S13, and abnormal temperature detection is performed. The abnormal temperature detection is performed by the temperature sensor 28, and it is determined whether the temperature at that time is 70 ° C. or less. If the temperature is 70 ° C. or less, the process returns to step S11 and the temperature raising process is continued. In S9, energization is stopped, heating is terminated, and an error is displayed on the display unit 20 in step S10, and rice cooking is cancelled.
[0050]
If it is determined in step S12 that the temperature at that time is higher than the temperature raising temperature, the process proceeds to step S14, where the unevenness process is started. Then, when the rice is cooked, the process proceeds to the heat retention process shown in FIG.
[0051]
Referring to the heat retention process of FIG. 6, when the heat retention process is started, a 3-hour timer is started in step S1. When the 3-hour timer starts, the room temperature at that time is originally read by the temperature sensor 28 in step S2. However, since the heat retention process here is the heat retention immediately after the rice cooking process, the temperature sensor 28 has a high temperature in the vicinity. Even if it is cooled by a cooling fan to some extent, the temperature does not drop in a short time, so the initial room temperature data read in step S4 of the rice cooking process is used to determine whether the initial room temperature is 12 ° C. or less.
[0052]
When the initial room temperature in step S2 is 12 ° C. or less, the heat retaining heater 9 is controlled to be heated at a duty ratio of 6/16 of the full output in step S3, and the lid heater 34 is set to the full output in step S4. Control is performed so that heating is performed at a duty ratio of 8/16.
[0053]
If the initial room temperature in step S2 is higher than 12 ° C., the process proceeds to step S5 to determine whether the initial room temperature is 25 ° C. or less. When the initial room temperature in step S5 is 25 ° C. or less, the heat retaining heater 9 is controlled to be heated at a duty ratio of 5/16 of all output in step S6, and the lid heater 34 is set to full output in step S7. Control is performed so that the heating is performed with a duty ratio of 6/16.
[0054]
When the initial room temperature in step S5 is higher than 25 ° C., the process proceeds to step S8, and the heat retaining heater 9 is controlled to be heated at a duty ratio of 4/16 of the total output. In step S9, the lid heater 34 is fully output. Thus, the heating is controlled so as to have a duty ratio of 4/16.
[0055]
In the heat retention control, any output control that is set according to the initial room temperature is performed, and at the same time, temperature measurement is performed by the inner pot sensor 11 at predetermined time intervals in the process, and the temperature is equal to or lower than the predetermined heat retention temperature. Is detected. If the temperature there is equal to or lower than the heat retention temperature, the bottom coil 12 and / or the corner coil 13 are controlled to be heated at a duty ratio of 1/16 of the total output in step S11, and if the temperature there is higher than the heat retention temperature. In step S12, the bottom coil 12 and the corner coil 13 are turned off. Thereafter, in step S13, it is determined whether or not 3 hours have elapsed. If it is determined that 3 hours have not yet elapsed, the process returns to step S2 and the heat insulation control according to the initial room temperature is continued.
[0056]
When it is determined in step S13 that 3 hours have elapsed, the continuous heat retention control shown in FIG. 7 is executed. The flow will be described with reference to FIG. If it is determined in step S13 in FIG. 6 that 3 hours have passed, the process proceeds to FIG. 7, where the room temperature is measured by the temperature sensor 28 in step S1, and the process proceeds to step S2 to perform subsequent heat insulation control based on the room temperature data. Is called.
[0057]
If it is determined in step S2 that the measured temperature is 12 ° C. or less, in step S3, the heat retaining heater 9 is controlled to be heated at a duty ratio of 6/16 of the full output, and in step S4, the lid heater 34 is set to the full output. Control is performed so that heating is performed at a duty ratio of 8/16.
[0058]
If it is determined in step S2 that the measured temperature is higher than 12 ° C., the process proceeds to step S5 to determine whether it is 25 ° C. or less. If it is determined in step S5 that the measured temperature is 25 ° C. or less, in step S6, the heat retaining heater 9 is controlled to be heated at a duty ratio of 5/16 of the full output, and in step S7, the lid heater 34 is set to the full output. Control is performed so that the heating is performed with a duty ratio of 6/16.
[0059]
If it is determined in step S5 that the room temperature is higher than 25 ° C., the process proceeds to step S8, where the heat retaining heater 9 is controlled to be heated at a duty ratio of 4/16 of the total output, and in step S9, the lid heater 34 is fully output. Thus, the heating is controlled so as to have a duty ratio of 4/16.
[0060]
As described above, any one of the output controls set according to the room temperature is performed as the heat retention control. Thereafter, the process proceeds to step S10, where it is determined whether or not the inner pot 10 is taken out and rice is newly cooked during the heat retaining process, and if it is determined that the inner pot 10 has been taken out, Assuming that rice cooking is performed, the cooling fan 25 is driven to control the temperature sensor 28 to be controlled.
[0061]
That is, in step S10, it is determined whether the heat retention temperature is 2 ° C. or less from the predetermined temperature. If it is determined that the temperature is 2 ° C. or less, the process proceeds to step S12, the presence / absence of the inner pot 10 is checked, and the process proceeds to step S13. Although the predetermined decrease temperature is detected in step S10, it can be changed to the predetermined decrease temperature, and a predetermined temperature change, that is, a temperature change per unit time can be used as a reference.
[0062]
And if it is judged that there is an inner pot 10 in step S13, the process proceeds to step S11, but if it is determined that there is no inner pot 10, the warming is canceled in step S14 and a new rice cooking is performed, step. In S15, a one minute timer is started, and in step S16, the cooling fan 25 is driven to cool the temperature sensor 28. Thereafter, in step S17, it is determined whether one minute has elapsed. If not, the process returns to step S16 to continue driving the cooling fan 25. However, after one minute has elapsed, this flow is terminated and the standby mode is entered. To do.
[0063]
If it is determined in step S10 that the temperature is not lower than 2 ° C., the process proceeds to step S11, and it is detected whether the temperature is equal to or lower than a predetermined heat retention temperature. If the measured temperature is equal to or lower than the heat retention temperature, the bottom coil 12 and / or the corner coil 13 are controlled to be heated at a duty ratio of 1/16 of the total output in step S18. If it is higher, the bottom coil 12 and the corner coil 13 are turned OFF in step S19. Thereafter, the process returns to step S1 and the heat insulation control according to the room temperature is continued.
[0064]
FIG. 8 shows an example of a flow for driving the cooling fan for a predetermined time when the heat retention during the heat retention is canceled. This flow is the same as that in FIG. 7 except for the part related to step S20. This example will be described with reference to the figure. When it is determined in step S13 in FIG. 6 that 3 hours have passed, the process proceeds to FIG. 8, where the room temperature is measured by the temperature sensor 28 in step S1, and the room temperature data is advanced to step S2. Thereafter, the heat insulation control is performed.
[0065]
If it is determined in step S2 that the measured temperature is 12 ° C. or less, in step S3, the heat retaining heater 9 is controlled to be heated at a duty ratio of 6/16 of the full output, and in step S4, the lid heater 34 is set to the full output. Control is performed so that heating is performed at a duty ratio of 8/16.
[0066]
If it is determined in step S2 that the measured temperature is higher than 12 ° C., the process proceeds to step S5 to determine whether it is 25 ° C. or less. If it is determined in step S5 that the measured temperature is 25 ° C. or less, in step S6, the heat retaining heater 9 is controlled to be heated at a duty ratio of 5/16 of the full output, and in step S7, the lid heater 34 is set to the full output. Control is performed so that the heating is performed with a duty ratio of 6/16.
[0067]
If it is determined in step S5 that the room temperature is higher than 25 ° C., the process proceeds to step S8, where the heat retaining heater 9 is controlled to be heated at a duty ratio of 4/16 of the total output, and in step S9, the lid heater 34 is fully output. Thus, the heating is controlled so as to have a duty ratio of 4/16.
[0068]
As described above, any one of the output controls set according to the room temperature is performed as the heat retention control. Thereafter, the process proceeds to step S10, where it is determined whether or not the inner pot 10 is taken out and rice is newly cooked during the heat retaining process, and if it is determined that the inner pot 10 has been taken out, Assuming that rice cooking is performed, the cooling fan 25 is driven to control the temperature sensor 28 to be controlled.
[0069]
That is, in step S10, it is determined whether the heat retention temperature is 2 ° C. or less from the predetermined temperature. If it is determined that the temperature is 2 ° C. or less, the process proceeds to step S12, the presence / absence of the inner pot 10 is checked, and the process proceeds to step S13. Although the predetermined decrease temperature is detected in step S10, it can be changed to the predetermined decrease temperature, and a predetermined temperature change, that is, a temperature change per unit time can be used as a reference.
[0070]
And when it is judged that there is an inner pot 10 in step S13, it progresses to step S11, but when it is judged that there is no inner pot 10, it cancels heat retention in step S14, and newly cooked rice is performed. Assuming that a one-minute timer is started in step S15, the cooling fan 25 is driven and the temperature sensor 28 is cooled in step S16. Thereafter, in step S17, it is determined whether one minute has elapsed. If not, the process returns to step S16 to continue driving the cooling fan 25. However, after one minute has elapsed, this flow is terminated and the standby mode is entered. To do.
[0071]
If it is determined in step S10 that the temperature is not lower than 2 ° C., the process proceeds to step S11, and it is detected whether the temperature is equal to or lower than a predetermined heat retention temperature. If the measured temperature is equal to or lower than the heat retention temperature, the bottom coil 12 and / or the corner coil 13 are controlled to be heated at a duty ratio of 1/16 of the total output in step S18. If it is higher, the bottom coil 12 and the corner coil 13 are turned OFF in step S19. Thereafter, the process returns to step S1 and the heat insulation control is continued, and it is determined whether or not the heat insulation has been canceled in step S20 during the continuation.
[0072]
When the heat retention is canceled in step S20, the process returns to step S14, and the heat retention is canceled. In step S15, a one-minute timer is started, and in step S16, the cooling fan 25 is driven to cool the temperature sensor 28. Thereafter, it is determined whether or not 1 minute has passed in step S17. If not, the process returns to step S16 and the cooling fan 25 continues to be driven. Become.
[0073]
Next, FIG. 9 shows a flow in the case where the heat retaining process is started from the time when the heat retaining switch is pushed and pushed. When the heat retention switch is pressed, the heat retention process is started. When the heat retaining process is started, first, a one minute timer is started in step S1, and the cooling fan 25 is driven to cool the temperature sensor 28 in step S2. Thereafter, in step S3, it is determined whether one minute has elapsed. If not, the process returns to step S2 to continue driving the cooling fan 25. . If room temperature is measured, it will progress to step S5 and subsequent heat retention control will be performed based on the room temperature data.
[0074]
If it is determined in step S5 that the room temperature is 12 ° C. or less, in step S6, the heat retaining heater 9 is controlled to be heated at a duty ratio of 6/16 of the full output, and in step S7, the lid heater 34 is set to 8 of the full output. Control is performed so that heating is performed at a duty ratio of / 16.
[0075]
If it is determined in step S5 that the room temperature is higher than 12 ° C., the process proceeds to step S8 to determine whether it is 25 ° C. or less. If it is determined in step S8 that the room temperature is 25 ° C. or less, in step S9, the heat retaining heater 9 is controlled to be heated at a duty ratio of 5/16 of the full output, and in step S10, the lid heater 34 is set to 6 in the full output. Control is performed so that heating is performed at a duty ratio of / 16.
[0076]
If it is determined in step S8 that the room temperature is higher than 25 ° C., the process proceeds to step S11, and the heat retaining heater 9 is controlled to be heated at a duty ratio of 4/16 of the total output. In step S12, the lid heater 34 is fully output. Thus, the heating is controlled so as to have a duty ratio of 4/16.
[0077]
As described above, any one of the output controls set according to the room temperature is performed as the heat retention control. After that, when it is determined in step S13 that the heat retention temperature is equal to or lower than the predetermined temperature, in step S14, the bottom coil 12 and / or the corner coil 13 are controlled to be heated at a duty ratio of 1/16 of the total output. If it is determined that the temperature is higher than the heat retention temperature, the bottom coil 12 and the corner coil 13 are turned OFF in step S15. Thereafter, the process returns to step S4 and the heat insulation control is continued.
[0078]
The present invention is not limited to the configuration of the above-described embodiment, and can be appropriately changed in design without departing from the gist of the invention.
[0079]
【The invention's effect】
Since one temperature sensor can measure the room temperature and the abnormal temperature during cooking, the number of parts can be reduced, and the production cost can be reduced accordingly. In addition, the temperature in the vicinity of the substrate varies greatly depending on the state immediately before the start of rice cooking and at the time of heat retention, but since the temperature sensor is adjusted to the room temperature by turning the fan for cooling the heat generating components, it is possible to measure the room temperature more accurately. The rice cooking control and the heat insulation control can be performed satisfactorily. Furthermore, since the abnormal temperature during rice cooking can be detected quickly, the safety is greatly improved, and problems such as melting of the current fuse and turning off of the breaker can be prevented.
[Brief description of the drawings]
FIG. 1 is an overall cross-sectional view of a rice cooker according to the present invention.
FIG. 2 is a schematic perspective view of a control board to which a sensor of the present invention is attached.
FIG. 3 is a system block diagram of a control circuit portion of the present invention.
FIG. 4 is a schematic time chart of the whole process from a rice cooking process to a heat retention process.
FIG. 5 is a flowchart of a rice cooking process.
FIG. 6 is a flowchart of a heat retention process when the rice cooking process shifts to the heat retention process.
FIG. 7 is a flowchart when the pan is taken out during the heat retaining process.
FIG. 8 is a flowchart in a case where a cooling fan is rotated for a certain period of time when canceled during the heat retaining process.
FIG. 9 is a flowchart when starting from a heat retaining process with a heat retaining switch.
FIG. 10 is a cross-sectional view of a conventional rice cooker.
[Explanation of symbols]
1 ... Rice cooker 2 ... Container body
3 ... Lid 3a ... Hinge mechanism
3b ... Lock member 4 ... Outer case
4a ... Horizontal part 4b ... Vertical part
5 ... Inner case 5a ... Through hole
6 ... Shoulder member 7 ... Handle
8 ... Bottom case 8a ... Inlet
8b ... Exhaust port 8c ... Leg
9 ... Heat insulation heater 10 ... Inner pot
11 ... Inner pan sensor 12 ... Bottom coil
13 ... Corner coil 15 ... Front space
16 ... Operation board holding member 17 ... Operation board
18 ... Operation panel 19 ... Switch button
20 ... Display unit 22 ... Control board holding member
23 ... Control board 23a ... Notch
24 ... Screw 25 ... Cooling fan
25a ... Fan case 25b ... Rotary wing
26 ... heat sink 26a ... fin
26b ... Upper opening 26c ... Side opening
27 ... Electronic control element 27a, 50 ... IGBT
27b ... Diode bridge 28 ... Temperature sensor
31 ... Upper lid 32 ... Lower lid
33 ... Radiating plate 34 ... Cover heater
35 ... Inner cover 36 ... Insulation
37 ... Pressure control lid 38 ... Steam passage
39 ... Steam port 40 ... CPU
45 ... IGBT drive circuit 46 ... Pulse width modulation circuit
48 ... Inner pan temperature detection circuit 49 ... Temperature detection circuit
51 ... Resonant capacitor 53 ... Synchronous trigger circuit
54 ... Lid heater drive circuit 56 ... Insulation heater drive circuit
57 ... AC power supply

Claims (3)

An inner case capable of storing an inner pot and forming an inner wall; a container main body forming an outer wall; a lid member which can be opened and closed with respect to the container main body; a heat retaining heater; a heating means for performing electromagnetic induction heating; In a rice cooker comprising a substrate on which various electronic control elements including heating parts for controlling heating means are mounted, an inner pot sensor for detecting the temperature of the inner pot, and a cooling fan for cooling the heating parts, A sensor is provided in the vicinity of the heat-generating component, and at least the room temperature and the abnormal temperature of the heat-generating component are measured by the sensor, and the measurement data is used for heating control in the rice cooking process and / or the heat-retaining process, and the heat retention following the rice cooking process. During the process, the output of the warming heater is changed according to the initial room temperature data already measured by the sensor, and the warming measured by the inner pot sensor regardless of the room temperature. Every time changing the output of said heating means in response to the initial room temperature data, wherein I Oh at room temperature data before heating during cooking process takes place, the Oh Rukoto at room temperature data after driving the cooling fan Rice cooker. An inner case capable of storing an inner pot and forming an inner wall, a container main body forming an outer wall, a lid member that can be opened and closed with respect to the container main body, a heating means for performing electromagnetic induction heating, and controlling the heating means In a rice cooker comprising a substrate for mounting various electronic control elements including a heat generating component, an inner pot sensor for detecting the temperature of the inner pot, and a cooling fan for cooling the heat generating component, in the vicinity of the heat generating component The sensor is used to measure at least the room temperature and the abnormal temperature of the heat-generating component using the sensor, and the measurement data is used for heating control in the rice cooking process and / or the heat retaining process, and at the start of the rice cooking process, The measurement data is used as room temperature data for controlling the amount of heating, and is used as abnormal temperature data during the rice cooking process. At the beginning of the process, the initial room temperature data that has already been measured by the sensor is used, and during the subsequent warming, the room temperature at the subsequent warming measured by the sensor is used, and the initial room temperature data is heated during the rice cooking process. I Oh at room temperature data before is performed, rice cookers, characterized in Oh Rukoto at room temperature data after driving the cooling fan.   An inner case capable of storing an inner pot and forming an inner wall, a container main body forming an outer wall, a lid member that can be opened and closed with respect to the container main body, a heating means for performing electromagnetic induction heating, and controlling the heating means In a rice cooker comprising a substrate for mounting various electronic control elements including a heat generating component, an inner pot sensor for detecting the temperature of the inner pot, and a cooling fan for cooling the heat generating component, in the vicinity of the heat generating component The sensor is provided with a sensor, and at least the room temperature and the abnormal temperature of the heat-generating component are measured by the sensor, and the measurement data is used for heating control in the rice cooking process and / or the heat retaining process, and the temperature is suddenly lowered or lower than the heat retaining temperature. When the predetermined temperature is detected, the rice cooker is characterized by determining that the heat insulation has been completed and turning on the cooling fan.

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