JPH09266854A - Electric rice cooker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To quicken transfer to a target heat reserving temperature, and restrain the occurrence of shading-off from white of boilded rice by a droplet by supplying cooling air to the rice cooker side from an air blowing passage arranged on the rice cooker side at transfer time to a heat reserving process in an electric rice cooker having a fan to cool a heating part of a heating driving means through the air blowing passage. SOLUTION: Work coils C1 and C2 are turned on, and when rice cooking operation is started, an electromagnetic solenoid to open and close an exhaust hole 120a is turned on, and a fan motor 73 for cooling is also turned on. A boiling condition is maintained, and when a rice cooker temperature reaches a boiling-out completed temperature, a boiling-out process is finished, and the work coils C1 and C2 are once turned off, and an process is advanced to a steaming process. Next, when advanced to a heat reserving process, the electromagnetic solenoid to open and close the exhaust hole 120a is turned off, and the exhaust hole 120a is closed, and cooling air of a fan 73a is supplied to a side part from a rice cooker bottom part 2a through a second air blowing passage B of a center censor 22 part, and a rice cooker 2 is forcedly cooled, and the rice cooker temperature is quickly lowered to a target heat reserving temperature.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric rice cooker having a rice cooker cooling function.

[0002]

2. Description of the Related Art Generally, in an electric rice cooker, after the unevenness process is completed, a heating means such as a heater or a work coil is turned off to quickly lower the temperature to a target temperature retention temperature, and a nonuniformity / heat retention control sequence is entered. Has been adopted.

[0003]

However, the uneven temperature is usually as high as around 110 ° C, while the heat retention temperature is usually 72 ° C.
It is as low as around -60 ° C.

Therefore, when the heating means such as the work coil or the heater is turned off at the completion of the purging process,
It takes a considerable amount of time to decrease to the target heat retention temperature, and as a result of being kept at a high temperature for a long time, deterioration of rice such as yellowing is likely to occur. Further, during that time, there is a problem that droplets are likely to be generated due to condensation of water vapor on the lower surface of the inner lid and the like, and the droplets drop on the rice to cause white blur on the rice.

This tendency becomes more remarkable in a low-temperature heat retention sequence or the like in which the heat retention temperature is lower than in the past, which has been widely adopted recently.

[0006]

The present invention has been made for the purpose of solving the above problems, and in order to achieve the above object, the following effective problem solving means are provided. It is configured.

That is, the electric rice cooker according to the invention of claim 1 of the present application is a rice cooker, a heating means for heating the rice cooker, a heating drive means including a heat-generating component for heating and driving the heating means, and the heating means. In an electric rice cooker comprising a fan for cooling the heat-generating component of the driving means via a first blower passage, a second blower passage to the rice cooker side is provided, and a warming process is performed after the completion of the wiping process. At the time of transition of the above, the cooling air of the fan is supplied to the rice cooker side through the second air passage.

Therefore, the temperature of the rice cooker after the completion of the wiping step is reduced to the target heat retention temperature much faster than the conventional one by the cooling action of the cooling air, and deterioration of the rice such as yellowing and white blurring occur. The rice is also less damaged.

Further, in the electric rice cooker according to the second aspect of the present invention, the blower passage closing means for closing the outlet of the first blower passage to the outside at the time of shifting to the heat retaining step after completion of the purging step is provided. Since it is provided, the cooling air is reliably supplied from the second air passage to the rice cooker due to the increase in static pressure after the outlet is closed.

Therefore, the temperature of the rice cooker after the completion of the wiping step is reduced to the target heat retention temperature much faster than the conventional one by the cooling action of the cooling air, and deterioration of the rice such as yellowing and white blurring occur. The rice is also less damaged.

Further, the electric rice cooker according to the invention of claim 3 has the above-mentioned second invention in which the second air passage is provided, and further when the rice cook process or the transition to the heat retention process is completed, An air-flow-path closing means for closing the second air-flow path is provided, and at the time of the rice cooking process or the completion of the transition to the heat retention process when the target heat retention temperature is reached (and during the heat retention),
It is possible to prevent the rice cooker from being cooled by closing the air flow passage of No. 1 and the unnecessary cooling air to reduce the heating heat efficiency during rice cooking or heat retention.

Further, the electric rice cooker according to the invention of claim 4 is provided with an air blowing passage opening means for opening the second air blowing passage at the time of shifting to the heat retaining step after completion of the purging step of each of the above inventions. , Surely open the second air passage to cool the rice cooker, and aim for a quick transition from the purging process to the target heat retention temperature. As a result, deterioration of the rice such as yellowing and damage of the rice due to white blur are reduced.

Further, the electric rice cooker of the invention of claim 5 is
The cooling air is supplied to the rice cooker side of each of the above inventions for a predetermined set time, for example, after the completion of the purging process.
Therefore, by appropriately setting the set time in accordance with the cooling air supply time required to reduce the temperature to the target heat retention temperature under a predetermined air volume, an appropriate cooling control that reaches the target heat retention temperature in the shortest time is possible. Is possible.

Further, in the electric rice cooker according to the invention of claim 6, the supply of the cooling air to the rice cooker side of each of the above inventions is carried out, for example, until it specifically drops to a predetermined set temperature such as a target heat retention temperature. It is like this. Therefore, the rice cooker can be accurately cooled to the target heat retention temperature in the shortest time without performing the fan operation more than necessary.

[0015]

As a result of the above, according to the electric rice cooker of each of claims 1 to 6 of the present invention, in any case, a rapid reduction to the target heat retention temperature after the completion of the unevenness process is realized, Deterioration of rice such as yellowing due to long-term high temperature and white blur phenomenon of rice due to condensed droplets in the process of lowering the target heat retention temperature are suppressed to a minimum. As a result, it is possible to reliably keep the quality of the cooked rice as it is after cooking, and it is possible to provide delicious rice.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION

(Basic Configuration of Electric Rice Cooker Main Body and Control Circuit Section) FIGS. 1 to 4 show an electric rice cooker main body common to Embodiments 1 and 2 of the present invention, which will be described later, and a control circuit section thereof. .

First, the electric rice cooker is of an electromagnetic induction heating type having a work coil, for example. In addition, cooking rice and heat retention are also used.

That is, as shown in detail in FIG. 1, the electric rice cooker main body 1 includes a rice cooker (internal) made of an iron-based metal such as stainless steel capable of self-heating due to an eddy current induced inside. Pan 2), a synthetic resin bottomed cylindrical inner case (protective frame) 3 formed so that the rice cooker 2 can be arbitrarily set, and a cylinder which is an outer housing for holding the inner case 3. The outer case 4 is shaped like an outer case 4, and a lid unit 5 is provided on the upper part of a container body formed by integrating the outer case 4 and the inner case 3 so as to be openable and closable.

The bottom surface 3a of the inner case 3 and the side surface 3b.
As shown in the figure, the outer surface has two sets of first and second work coils C connected in series to each other by concentric first and second ribs 91 and 92 having different radial positions. ₁ ,
C ₂ is constructed so that it can be fitted at a predetermined interval, and the first and second work coils C ₁ and C ₂ are arranged in the radial direction via the first and second ribs 91 and 92. The bottom surface 3a on the inner side and the outer surface of the side portion 3b on the outer side are joined and fixed to the fitting surfaces via adhesives.

Therefore, in the above construction, the rice cooker 2 uniformly generates heat on both the bottom 2a side and the side 2c side, and cooks rice cooked in water in the rice cooker 2 efficiently without uneven heating.

An IG for driving and controlling the first and second work coils C ₁ and C ₂ is provided on the lower side of the inner case 3.
A control circuit board 36 having heat-generating components such as a smoothing circuit including a BT 50 and a diode bridge for power supply voltage rectification is attached.

The outer case 4 is composed of, for example, a synthetic resin plate and has a vertically cylindrical cover portion 4a, and a synthetic resin shoulder portion 4b connected to the upper end portion of the cover portion 4a.
A cylindrical body having a bottom as a whole in a state where a space portion 6 having a predetermined width is formed between the bottom portion 3a of the inner case 3 and a bottom portion 4c made of a synthetic resin joined to the lower end portion of the cover portion 4a. Is configured.

The space 6 in the bottomed cylindrical body is located on the lower surface of the inner case 3 on the front end side, and is provided with a fan 73a and a fan motor 73, and the work coils C ₁ and C ₂ are provided. IGBT50 for driving and power supply circuit 7
The first air passage A (see the broken line arrow) through which the cooling air for cooling the heat-generating components such as 9 is formed, and is provided at the outlet of the first air passage A, that is, on the side opposite to the fan 73a. An exhaust port portion 120 having a grill structure having an openable and closable shirt S is provided at a lower position of the opposing outer case 4. On the other hand, at the position of the outer case bottom 4c below the fan 73a, an air inlet 116 of the same grill structure is provided.

The exhaust port 120 and the shirt S are constructed, for example, as shown in FIG. That is, the shirt S is slid sideways in parallel with and supported by the pair of upper and lower guide groove members 118a and 118b with respect to the exhaust port 120 of the grill structure, and the electromagnetic solenoid (electromagnetic plunger) 117 is turned on or off. When it is driven to the OFF state, it can be slid arbitrarily in the arrow (a) or (b) direction by turning it off.
In the exhaust direction, the opening Sa is moved to the exhaust port 120.
Corresponding to the exhaust hole 120a of the exhaust hole 12
When 0a is opened and driven to the ON state, it operates in the direction (a), and the blind portion Sb portion is exhausted to the exhaust hole 1 of the exhaust port portion 120.
By corresponding to 20a, the exhaust hole 120a is closed.

The outer case 4 has the inner case 3 made of synthetic resin and formed in the same cylindrical shape with a bottom for setting the rice cooker 2 so that the rice cooker 2 can be freely taken out as described above. I support you.

A bottom surface is provided at a portion between the first and second ribs 91 and 92 for partitioning the inner and outer first and second work coils C ₁ and C _{2 on the} outer peripheral portion of the bottom portion 3a of the inner case 3. A thin portion 30 that is a concave portion is formed on the side, and the lower surface side of the thin portion 30 is a microcomputer for cooking rice, which includes the first and second work coils C ₁ and C ₂ and a microcomputer during abnormal heating. A thermal fuse 15 is provided for shutting off power to the control unit (see reference numeral 61 in FIG. 4, which will be described later).
The inner and outer first and second work coils C ₁ and C 2 are formed on the lower surface of the bottom portion 3a and the outer surface of the side portion 3b of the inner case 3 as described above.
C ₂ is provided, and a coil base 8 is provided below them.

An operation panel section 100 is provided on the front side of the cover section 4a of the outer case 4, and an operation board 101 provided with the microcomputer control unit (see reference numeral 61 in FIG. 4) and the like is provided on the back side thereof. Has been.

The operation panel section 100 is provided with various operation switches, a rice cooker set by these various switches, a display section for displaying a heat retention state, and the like.

Further, as described above, below the coil base 8, the inside and outside first and second work coils C ₁ and C ₂ are provided by the microcomputer control unit including the microcomputer on the operation board 101 side. There is provided a control circuit board 36 having a work coil control circuit for performing energization and ON / OFF control (output duty control) during energization, and a fan drive circuit (see FIG. 4) for performing fan motor drive control according to the rice cooking process. ing.

By the way, the coil base 8 extends radially in the radial direction, for example, and has an inner case supporting surface having a saucer shape as a whole, and has the inner and outer first and second work coils C ₁ and C _{2 respectively.}
Rib-shaped work coil supporting portions 8a, 8a
., And the ferrite core fitting grooves 9, 9 formed between the work coil supporting portions 8a, 8a ... And the leg portion 1 provided on the lower side of the work coil supporting portions 8a, 8a.
0, 10 ... And the above-mentioned leg portion 10, 10
.. is supported on the bottom portion 4c of the outer case 4. The work coil supporting portions 8a, 8 of the coil base 8
On the side outer peripheral surface of a ..., a pair of spacers 11, 11 having a vertical wall structure, which are located on both sides of one end (radial outer end) of the ferrite core fitting groove 9, 9 ,. Are provided, and the outer second work coil C is provided around the outer periphery of the spacers 11 and 11 with a predetermined space therebetween.
A ring-shaped magnetic shield plate 12 for shielding the magnetism from ₂ is fitted and fixed from the lower side.

Further, the ferrite core fitting grooves 9, 9
The ferrite cores 13 and 13 are formed, for example, so as to extend in the radial direction at intervals of 90 degrees in the circumferential direction, and penetrate vertically, and at predetermined intervals in the radial direction. Is fitted.

On the other hand, the inner case 3 is integrally formed with a bottom portion 3a and a side wall portion 3b, and the center portion of the bottom portion 3a and the work coil supporting portions 8a, 8a of the coil base 8 have a substrate central portion. As shown in detail in FIG. 3, a storage space (fitting hole) 17 for the center sensor 22 penetrating vertically concentrically is formed, and the center sensor storage space 17 can be vertically moved up and down. The center sensor 22 for detecting the set state of the rice cooker is provided in such a state that the coil spring 18 constantly urges upward.

The center sensor housing space 17 is formed in a cylindrical body 19 formed by ribs extending vertically in the central portion of the coil base 8, and a sensor cover 20 is fitted into the lower opening thereof. The screws 21 are fixed to the pressure wall portion on one side of the coil base 8 side tubular body 19 with screws 21.

The cover wall of the sensor cover 20 has a thermistor (23a) and a lead switch (29) which will be described later.
In addition to the lead wire lead-out hole 111, the openings 112, 112 ...
・ Is formed. Then, when the exhaust hole 120a of the exhaust port 120, which is the outlet of the first air passage A, is closed by the blind portion Sb of the shirt S, the second air passage B shown in the drawing, that is, the opening 112. , 112 ... Or the lead wire outlet 111 introduces the cooling air by the rotation of the fan 73a into the center sensor storage space 17, and the cooling air between the sensor holder (26) and its sensor cap (25) described later is introduced. The rice cooker 2 is supplied through the gap 113 between the rice cooker 2 and the inner case 3 to efficiently cool the outer peripheral surface (bottom surface to side surface) of the rice cooker 2.

The cooling of the rice cooker 2 through the second air passage B is used to quickly lower the rice cooker temperature to the heat retention temperature, for example, after the wiping step is completed, as will be described later in detail. To be done.

In the case of the present embodiment, the center sensor 22 has, for example, a large-diameter temperature fuse for detecting an abnormal temperature provided in the sensor holding portion 94 inside the upper end of the cylindrical sensor holder 26. The thermistor for detecting the temperature of the rice cooker 2 which is considerably smaller than the temperature fuse.
Only the (temperature sensor) 23a is provided in the central portion and the upper surface of the sensor holding portion 94 inside the upper end portion of the sensor holder 26 covers the small diameter sensor holding portion 94 provided with only the thermistor 23a. Enough for
A sensor cap 25 made of a metal material having a small diameter and good thermal conductivity is integrally fitted and fixed. A rib 26a is provided at an intermediate portion of the cylindrical sensor holder 26, and the rib 26a and the lid upper surface 2 of the lower sensor cover 20 are provided.
The entire coil holder 18 is supported by the coil spring 18 interposed between the sensor holder 26 and the coil spring 7 so that the sensor holder 26 can be moved up and down and is always urged upward.

The lower portion of the sensor holding portion 94 inside the upper end of the sensor holder 26 extends downward by a predetermined length in the shape of a rectangular tube and the magnet 28 is attached to the lower end thereof, while the lower sensor cover 20 has a cylindrical lead. A switch mounting portion 95 is provided. Then, the reed switch 29 mounted on the reed switch mounting portion 95 and the magnet 28 are brought into contact with and separated from each other according to the ascending / descending operation of the sensor holder 26, thereby turning on / off the reed switch 29.
The rice cooker 2 is set to FF, and the ON / OFF signal is used to detect the set state or non-set state of the rice cooker 2.

The temperature of the rice cooker 2 is detected by the thermistor 23a.

Reference numeral 34 is a rising position regulating edge portion of the sensor holder 26 of the inner case bottom portion 3a, and the edge portion 34 is erected at a predetermined height above the upper surface of the inner case bottom portion 3a, and the center portion is raised. It is made difficult for water and the like to enter the sensor storage space 17.

On the other hand, the lid unit 5 has a synthetic resin outer cover 37 constituting the outer peripheral surface thereof and the outer cover 37.
The rice cooker 2 of the lid unit 5 fitted inside the outer peripheral edge of the
Radiating plate 5 including an inner frame 38 made of a synthetic resin that constitutes an engaging portion to the inner frame 38, and a lid heater 72 fitted in the inner frame 38.
The outer cover 37 and the heat dissipation plate 57 are connected to each other at their outer peripheral edge portions via an inner frame portion 38. The lid unit 5 is rotatably attached to a shoulder 4b of the outer case 4 via a hinge mechanism 40, and has an open end engaged with a predetermined position of the lid unit 5. A lock lever 39 for opening and closing the lid unit 5 is provided.

Further, in the substantially central portion of the lid unit 5,
The vapor discharge port 43 is formed so as to penetrate vertically.
A rubber packing 45 is provided in the steam discharge port 43.
Are fitted, and the vapor discharge cylinder 44 is attached via the packing 45.

Next, FIG. 4 shows the construction of the work coil control circuit section centering on the rice cooking microcomputer control unit 61 of the electric rice cooker configured as described above.

In the figure, reference numeral 61 is a microcomputer control unit (CPU) for rice cooking control provided on the operation board 101 on the back side of the front operation panel 100 of the outer case 4, and the microcomputer control unit 61 is a micro controller. Centering on the computer, temperature detection circuit section, work coil control circuit section, oscillation circuit section, reset circuit section, lid heater drive circuit section, fan motor drive circuit section, shirt solenoid drive circuit section, power supply circuit section, liquid crystal display section, It is configured to include an LED lamp display section, an operation switch section, and the like.

First, for example, a detection value of the temperature of the rice cooker 2 (rice temperature) by the thermistor 23a is input to the temperature detection circuit 23.

The work coil control circuit section includes a pulse width modulation circuit 53, a synchronous trigger circuit 54, and an IGBT.
It is formed by the drive circuit 52, the IGBT 50, and the resonance capacitor 51. Then, by controlling the pulse width modulation circuit 53 by the microcomputer control unit 61, for example, according to the total number (rice cooking amount),
By appropriately variably controlling the heating temperature of the rice cooker in each step of the rice cooking process, such as by changing the total output (output duty ratio) of the second work coils C ₁ and C ₂ , it is possible to appropriately control as described later. Output control is performed to realize the cooking of rice.

Reference numeral D in the figure is a flywheel diode of the IGBT 50. Further, reference numeral 71 is
The first and the second inserted between the household AC power source 70 and
Power supply side smoothing circuit for the work coils C ₁ and C ₂ .

On the other hand, reference numeral 72 is the above-mentioned lid heater, 73 is a fan motor for driving the fan 73a at the inner bottom portion of the outer case 4, 117 is an electromagnetic solenoid for driving the shirt S, via triacs 74, 75, 76, respectively. The TRIAC drive circuit 77 is turned on and off. The lid heater 72, fan 73, electromagnetic solenoid 11
The ON / OFF control corresponding to the rice cooked state 7 is performed by controlling the triac drive circuit 77 by the microcomputer control unit 61.

Reference numeral 78 is a step-down transformer, and 79 is a constant voltage power supply circuit, which forms a power supply circuit of the microcomputer control unit 61.

Further, reference numeral 62 is a liquid crystal display section, 63 is an LED lamp section for performing various displays such as rice cooking display, heat retention display, reservation display and timer display, and 64 is a rice cooking start switch, heat retention switch, timer switch, cancel switch. Etc. Various operation switch parts, 65 is an oscillation circuit for control, 80
Is a reset circuit.

(Embodiment 1) FIGS. 5 and 6 show the contents of rice cooking / heat retention control according to Embodiment 1 of the present invention, which is carried out using the electric rice cooker body having the above-described configuration.

The contents of the control will be described in detail with reference to FIGS. 5 and 6.

That is, first, when the above-mentioned rice-cooking start switch is pressed without setting the timer, or when the reserved time at which the timer is set is reached, the buzzer is notified of the start of the rice-cooking and the work coils C ₁ and C ₂ are turned on to start the rice-cooking operation. Is started (step S ₁ ). At the same time cooking LED lamp ON (Step S _2), to an electromagnetic solenoid 117 ON for the exhaust hole 120a opened (Step S _3), ON the fan motor 73 for cooling (Step S ₄₎ . Then, as a result, the water absorption step is first executed within the predetermined water absorption time (step S ₅ ).

Next, when the water absorption time has elapsed and the water absorption process is completed, the outputs of the work coils C ₁ and C ₂ are brought to the full power state to quickly raise the rice cooker temperature and judge the sum. (step S _6).

Then, when the temperature of the rice cooker reaches the boiling temperature of 100 ° C., the cooked rice is cooked by maintaining the boiling state until the temperature of the rice cooker reaches the cooking completion temperature of 130 ° C. (step S ₇ ). .

Then, the temperature of the rice cooker is cooked up to the completion temperature 13
When the temperature reaches 0 ° C., the cooking process is terminated and the work coils C ₁ and C ₂ are once turned off to proceed to the unevenness process (step S ₈ ).

In the purging process, the work coil C ₁ ,
Setting the rice cooker temperature by turning off C ₂
The output control of the work coils C ₁ and C ₂ is restarted after the decrease of the temperature is reduced to 110 ° C. within the predetermined set time, and the cooked rice is made sufficiently uneven.

Next, when the nonuniformity time has elapsed, the work coils C ₁ and C ₂ are turned off again and the buzzer is informed of the completion of rice cooking (step S ₉ ), and the rice cooking LED lamp is turned off (step S ₁₀ ). After that, proceed to the next heat retention step.

[0058] In heat insulating step, lighting warmth LED lamp firstly in terms of displaying that it has entered (step S ₁₁₎ is allowed by incubating process, the outlet portion by the electromagnetic solenoid 117 for the exhaust hole 120a opened and closed OFF 120 exhaust holes 12
Close 0a (step S _12). Thereafter, further starts the ON state continuation process of the fan motor 73 (step S ₁₃₎ the timer operation of the 60-minute timer that sets the driving time of 60 minutes the fan motor 73 performs (decrement) (Step S _14).

As a result, the work coils C ₁ and C _{2 are}
In addition to the natural decrease of the rice cooker temperature by turning off the
The cooling air of a is supplied from the bottom part 2a of the rice cooker to the side portion through the second air passage B of the center sensor 22 portion, and the rice cooker 2 is forcibly cooled to further promote the temperature drop of the rice cooker. Control to be done.

As a result, the rice cooker temperature quickly drops to the target heat retention temperature of 72 ° C.

Therefore, it is next determined whether or not the temperature of the rice cooker has actually dropped to the target heat retention temperature of 72 ° C. or lower (step S ₁₅ ).

As a result, if YES, the work coils C ₁ and C ₂ are turned on with a small output (duty ratio 1/16) so that the temperature does not drop below the target temperature 72 ° C. (step S ₁₆ ). On the other hand, when NO, the work coil C ₁ ,
When the OFF state of C ₂ is continued, or when it was previously turned ON (when step S ₁₆ has been passed last time), the work coil C ₁ or C ₂ is turned OFF again so that the target heat retention temperature 72 is reached. Lower the rice cooker temperature to ℃ (Step S
₁₇ ). In this way, the heat retention at the target heat retention temperature of 72 ° C. is continued.

Further, it is determined whether or not the temperature in the vicinity of the lid heater 72 has become 90 ° C. or less at which droplets are likely to be generated in the heat retaining state (step S ₁₈ ). If NO, the lid heater 72 is turned off. (Step S ₁₉ ) while YE
When S, the lid heater 72 is set to O at a duty ratio of 9/16.
In the N (step S ₂₀₎ to prevent the white blur occurs in rice as possible by evaporating the droplets (soup) occurring on the lower surface the radiating plate 57.

[0064] Thereafter, followed by completion of the timer operation of the 60-minute timer, i.e. determining the course of the fan drive setting time of 60 minutes (step S _21), until the time of NO becomes YES, and step S ₁₅ to S The target heat retention temperature maintenance control of ₂₁ and the droplet evaporation control are repeated.

[0065] On the other hand, becomes to YES, the stop forced cooling of the fan motor 73 in the OFF rice unit 2 (step S ₂₂₎ to, to S ₁₆ · Step S ₁₅ within a set incubation time
Continuing the original insulation and droplet evaporation control of _{S 17 ~S 18 ~S 19 · S} 20 ~S 21 ~S 15.

As a result, according to the heat retention control system,
The following actions can be obtained.

That is, at the time of shifting to the heat retention process after the completion of the purging process, the exhaust holes 12 at the outlet of the first air passage A
0a is closed and the fan motor 73 is driven for a preset time of 60 minutes, and the cooling air from the fan 73a travels from the bottom surface to the side surface of the rice cooker 2 through the second air passage B of the center sensor 22. It is supplied and the rice cooker 2 is forcibly and efficiently cooled.

Therefore, for example, as shown in FIG. 6, the rice bowl temperature of 72 ° C. is much faster than the natural decrease of the rice bowl temperature only by turning off the ordinary work coils C ₁ and C _2. The temperature is lowered, and it becomes possible to shift to the original heat retention control in the shortest possible time.

Therefore, the rice is deteriorated due to a long high temperature from the completion of the purging process until the temperature is lowered to the target heat retention temperature, and the large amount of droplets is generated due to a long temperature decrease time. Reduction of white blur is reduced and a good heat retention state is realized.

(Embodiment 2) The flow chart of FIG. 7 shows the contents of rice cooking / heat retention control according to Embodiment 2 of the present invention, which is carried out by using the electric rice cooker body having the configuration of FIGS. Is shown.

The contents of the control will be described in detail with reference to the flowchart of FIG.

That is, first, when the above-mentioned rice-cooking start switch is pressed without setting the timer, or when the reserved time at which the timer is set comes, the buzzer is notified of the start of the rice-cooking and the work coils C ₁ and C ₂ are turned on to start the rice-cooking operation. Is started (step S ₁ ). At the same time cooking LED lamp ON (Step S _2), ON (Step S ₃₎ the electromagnetic solenoid 117 for opening the exhaust hole 120a of the outlet portion 120, for the cooling fan motor 73
Is turned on (step S ₄ ). Then, the water absorption step is first executed within the predetermined water absorption time (step S ₅ ).

Next, when the water absorption process is completed after the water absorption time has elapsed, the outputs of the work coils C ₁ and C ₂ are brought to the full power state to quickly raise the rice cooker temperature and judge the sum. (step S _6).

After that, when the temperature of the rice cooker reaches the boiling temperature of 100 ° C., the cooked rice is cooked by maintaining the boiling state until the temperature of the rice cooker reaches the cooking completion temperature of 130 ° C. (step S ₇ ). .

Then, the rice cooker temperature is cooked up to the completion temperature 13
When the temperature reaches 0 ° C., the cooking process is terminated, the work coils C ₁ and C ₂ are once turned off, and the unevenness process (step S ₈ ) is performed.

In the purging process, the work coils C ₁ ,
Setting the rice cooker temperature by turning off C ₂
The output control of the work coils C ₁ and C ₂ is restarted after the decrease of the temperature is reduced to 110 ° C. within the predetermined set time, and the cooked rice is made sufficiently uneven.

Next, when the nonuniformity time has elapsed, the work coils C ₁ and C ₂ are turned off again, the buzzer is informed of the completion of rice cooking (step S ₉ ), and the rice cooking LED lamp is turned off (step S ₁₀ ). After that, proceed to the next heat retention step.

[0078] In heat insulating step, lighting warmth LED lamp firstly in terms of displaying that it has entered (step S ₁₁₎ is allowed by incubating process, the outlet portion by the electromagnetic solenoid 117 for the exhaust hole 120a opened and closed OFF 120 exhaust holes 12
Close 0a (step S _12). Thereafter, it continued driving of the fan 73a go further ON state continuation process of the fan motor 73 (step S _13).

As a result, the work coils C ₁ and C _{2 are}
In addition to the natural decrease of the rice cooker temperature by turning off the
The cooling air of a is supplied from the bottom face portion of the rice cooker 2 to the side face portion via the second air passage B of the center sensor 22 portion.
By forcibly cooling the whole, the temperature drop of the rice cooker is further promoted.

As a result, the rice cooker temperature quickly drops to the target heat retention temperature of 72 ° C.

Then, it is next determined whether or not the temperature of the rice cooker 2 has actually dropped to the target heat retention temperature of 72 ° C. or lower (step S ₁₄ ).

As a result, when the temperature of the rice cooker has not fallen to 72 ° C. or lower, the work coils C ₁ and C ₂ are turned off and the wind of the fan 73a is continuously supplied to the rice cooker 2 side. By doing so, the rice cooker temperature is quickly lowered to the target heat retention temperature of 72 ° C. (step S ₁₅ ). In this way, the work coils C ₁ and C ₂ are turned off, and the control for promptly lowering the temperature to the target heat retention temperature 72 ° C. by the forced cooling of the rice cooker 2 is executed.

Further, in this state, the lid heater 7
It is determined whether or not the temperature around 2 has become 90 ° C. or less at which droplets are likely to be generated (step S ₁₆ ), and the lid heater 72 is turned off (step S ₁₇ ) in the case of NO, while it is YES in the case of YES. Turn on the lid heater 72 at a duty ratio of 9/16
By (Step S ₁₈ ), the droplets (tsuyu) generated on the lower surface of the heat dissipation plate 57 are evaporated to prevent the occurrence of white blur on the rice as much as possible.

[0084] Then, in step S ₁₄ again determines the temperature drop to the target retained temperature 72 ° C., when the NO Until YES, and reduction control to the target retained temperature of step S ₁₅ to S _18, and The droplet evaporation control is repeated.

On the other hand, when the rice cooker temperature drops to the target heat retention temperature and becomes YES, the fan motor 73 is turned off (step S ₁₉ ) to stop the forced cooling of the rice cooker 2,
Again, it is determined whether or not the temperature of the rice cooker 2 has actually dropped to the target heat retention temperature of 72 ° C. or lower even after the fan motor 73 is turned off (step S ₂₀ ).

As a result, when the YES rice cooker temperature is surely lowered to the target heat retention temperature of 72 ° C., the work coil C is set.
₁ and C ₂ are turned on with a small output (duty ratio 1/16) so as not to fall below the target heat retention temperature of 72 ° C. (step S ₂₁ ). On the other hand, when NO, the work coil C ₁ ,
When the OFF state of C ₂ is continued, or when it was previously turned on (when the previous step S ₂₁ has been passed), the target heat retention temperature 72 is set by turning off the work coils C ₁ and C ₂ again. Lower the rice cooker temperature to ℃ (Step S
₂₂ ). In this way, the heat retention temperature maintaining control at the target heat retention temperature of 72 ° C. is continued.

Further, in the heat retention control state, it is judged whether or not the temperature in the vicinity of the lid heater 72 has become 90 ° C. or lower at which the liquid droplets are generated (step S ₂₃ ), and if NO, the lid heater 72. Is turned off (step S ₂₄ ),
White blurring in rice as possible by evaporating the ON droplets occurring in the lower surface radiating plate 57 in the (step S ₂₅₎ (soup) of the lid heater 72 at a duty ratio of 9/16 when a YES Prevent it from happening.

[0088] Thereafter, each returns to retained temperature judgment operation in the step S _20, the original insulation in the step _{S 20 ~S 21 · S 22 ~S} 23 ~S 24 · S 25 ~S 20 sets the holding time And the droplet evaporation control is continued.

As a result, according to the heat retention control system,
The following actions can be obtained.

That is, at the time of shifting to the heat retaining step after the completion of the wiping step, the exhaust hole 120a at the outlet of the first air passage A is closed until the temperature of the rice cooker drops to the target heat retaining temperature of 72 ° C. 73 is driven, and the cooling air from the fan 73a is supplied from the bottom surface of the rice cooker 2 to the side surface of the rice cooker 2 via the second air passage B of the center sensor 22 to forcibly and efficiently cool the rice cooker 2. It

Therefore, as in the case of FIG. 6 described above, compared to the normal natural decrease in the temperature of the rice cooker only by turning off the work coils C ₁ and C ₂ , the warming that the rice cooker temperature becomes a target is much faster. The temperature is lowered, and it becomes possible to shift to the original heat retention control in the shortest possible time.

Therefore, the rice is deteriorated due to a long high temperature state from the completion of the purging process until the temperature is lowered to the target heat retention temperature, and the large amount of droplets is generated due to a long temperature decrease time. White blur reduction is surely reduced, and a good heat retention state is realized.

In each of the above embodiments, the lid heater is used to remove the liquid droplets for preventing the white blur, but the same control can be performed by using the shoulder heater. .

(Modification) By the way, in the structure of the electric rice cooker body described above, for example, as shown in FIG. 3, the thermistor 23a for controlling the heating temperature of the rice cooker and the leads are provided on the cover wall of the sensor cover 20. In addition to the lead wire drawing hole 111 of the switch 29 and the like, the openings 112, 112 ... Having a predetermined diameter to be the cooling air introduction ports of the second air passage B described above are formed, while the first air passage A of the first air passage A is formed. A shirt S for opening and closing the exhaust hole 120a of the exhaust port 120, which is an outlet, is provided, and when the blind hole Sb of the shirt S closes the exhaust hole 120a of the exhaust port 120, the opening 112,
112 or the lead wire outlet 111 introduces the cooling air by the rotation of the fan 73a into the center sensor storage space 17, and the rice is passed through the gap 113 between the sensor holder 26 and the sensor cap 25 described later. It is supplied between the cooker 2 and the inner case 3, and the outer peripheral surface (bottom surface ~
The side surface is configured to be cooled efficiently.

Therefore, in this structure, the openings 112, 112 ... And the lead wire lead-out hole 111 in the cover wall of the sensor cover 20 are the same as the exhaust hole 1 of the exhaust port 120.
Regardless of whether the shirt 20 is opened or closed by the shirt S, it is always in communication with the fan 73a side. Therefore, although the exhaust hole 120a of the exhaust port 120 is open to the outside, for example, some cooling air is blown to the rice cooker 2 side even during the rice cooking process or when the transition to the heat retention process when the target heat retention temperature is reached is completed. There is a possibility that it will be supplied, and there is concern that the heating efficiency during rice cooking or heat retention may decrease.

On the other hand, as described above, the first air duct A
In the configuration in which the shirt S is provided at the exhaust port 120, which is the most downstream part, and the outlet of the first air passage A is opened and closed, for example, the blind Sa of the shirt S causes the exhaust to be exhausted. It takes a certain amount of time for the static pressure in the space 6 below the inner case 3 to increase after the exhaust hole 120a of 120 is closed, in view of the size of the space volume. Therefore, there is some difficulty in the responsiveness of introducing cooling air to the rice cooker 2 side through the second air passage B.

Therefore, in order to solve the problem, in another embodiment of the present invention, the configurations as shown in FIGS. 8 and 9 are adopted as necessary.

That is, in this structure, as shown in FIGS. 8 and 9, the lower cylindrical portion 20A of the sensor cover 20 described above is used.
Is used to fit a lid 130 as shown in the drawing, and the lid 1
An opening 131 having a predetermined opening diameter is formed through 30 in the vertical direction.

On the other hand, an opening / closing member 132a having a plug structure for fitting and non-fitting the opening 131 to arbitrarily open and close the opening 131 is provided on the lower portion 4c of the outer case, and the opening / closing member 132a is provided. It is supported by an electromagnetic plunger 132 so that it can move up and down.

Furthermore, in addition to this, the outer case bottom portion 4 located in the middle of the above-mentioned first air passage A and below the end portion of the lid body 20A downstream of the opening 131.
On the wall c, for example, a hinge 133 is rotatably and rotatably supported by a hinge 133, and is driven up and down as shown by an arrow in the figure by an electromagnetic actuator such as a motor or an electromagnetic plunger.
Is provided. A pair of enclosing walls 135, 135 are arranged side by side on the upstream side of the collision wall 134 so as to sandwich the lid 130.

In the above configuration, for example, the electromagnetic plunger 132 for operating the opening / closing member 132a and the electromagnetic actuator for operating the partition wall 134 are driven and controlled by the microcomputer control unit 61, respectively. In the state where the transition to the heat retention step is completed when the temperature reaches the above, first, as shown in FIG.
The opening 131 is closed by the opening / closing member 132a to completely close and block the second air passage B so as not to lower the heating efficiency of the rice cooker 2 and the wall 134 is tilted horizontally to exhaust the air from the fan 73a. The first air passage A to the part 120 side is communicated with each other to efficiently cool the electric components.

On the other hand, at the time of shifting to the "heat retention step" after the completion of the "purging step" as described above, the opening / closing member 1 as shown in FIG.
32a is lowered to open the opening 131, while the abutment wall 134 is raised to enclose the walls 131 and 135 on three sides of the opening 131, and the cooling air from the fan 73a responds through the opening 131. The sensor cover 20 is introduced into the sensor housing space 17 through the openings 112, 112, ... As a result, the rice cooker 2 is efficiently cooled, and a quick transition to the target heat retention temperature is realized. In this configuration, in addition to the thermistor 23a for controlling the heating temperature of the rice cooker, the thermistor 2 for detecting an abnormal temperature is used.
3b is also provided together.

In this structure, the exhaust port portion 120 as described above is used.
The part of the shirt S can be omitted.

Of course, the abutment wall 13 in the structure is
4, instead of the enclosure walls 135, 135, the shirt S
It is also possible to employ.

Further, the collision wall 134 and the enclosure wall 13
It is also possible to adopt a configuration in which, for example, the opening 131 is simply opened and closed by the opening / closing member 132a without employing 5,135 or the shirt S.

Further, according to the present invention, in addition to the above-mentioned constitutions, at the time of cooling the rice cooker 2 using the second air passage B, the rotation speed of the fan 73a is also controlled to be high and the air blowing ability is also increased. If necessary, a configuration that improves the cooling efficiency and further improves the cooling efficiency is also adopted.

Furthermore, the heating means of the electric rice cooker body described above may be replaced by a heater, for example, a work coil.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an electric rice cooker body common to each embodiment of the present invention.

FIG. 2 is an enlarged rear view of a closed state of an exhaust port portion, which is one of the main parts of the electric rice cooker body.

FIG. 3 is an enlarged cross-sectional view of a second air passage portion, which is one of the main parts of the electric rice cooker body.

FIG. 4 is a block diagram of a control circuit unit centered on a microcomputer control unit of the electric rice cooker.

FIG. 5 is a flowchart showing the contents of rice cooking / heat retention control according to the first embodiment of the present invention.

FIG. 6 is a time chart corresponding to the contents of rice cooking / heat retention control of FIG.

FIG. 7 is a flowchart showing the contents of rice cooking / heat retention control according to the second embodiment of the present invention.

FIG. 8 is a first operating state showing a configuration of each opening / closing portion of a second air passage and a first air passage of a modified example of the configuration of the electric rice cooker main body commonly used in the respective embodiments of the present invention. FIG.

FIG. 9 is a second operating state showing a configuration of each opening / closing portion of the second air passage and the first air passage of the modified example of the configuration of the electric rice cooker main body commonly used in the respective embodiments of the present invention. FIG.

[Explanation of symbols]

1 is an electric rice cooker, 2 is a rice cooker, 3 is an inner case, 4 is an outer case, 23 is a temperature detection circuit section, 23a is a thermistor, 61
Is a microcomputer control unit, C ₁ is an inner first work coil, C ₂ is an outer second work coil, 73 is a fan motor, 73a is a fan, 116 is an air intake port, 117 is an electromagnetic solenoid, and 120 is an exhaust port. , 120a is an exhaust hole, S is a shirtter, and Sa is an opening hole of the shirtter.

Claims (6)

[Claims] 1. A rice cooker and heating means for heating the rice cooker,
An electric rice cooker comprising: a heating driving means including a heating element for heating and driving the heating means; and a fan for cooling the heating element of the heating driving means via a first air passage. It has a second air blowing path to the rice cooker side, and is configured to supply the cooling air of the fan to the rice cooker side through the second air blowing passage when the heat retention step is completed after the purging process is completed. Electric rice cooker characterized by being. 2. The electric rice cooker according to claim 1, further comprising blower passage closing means for closing an outlet portion of the first blower passage to the outside at the time of shifting to the heat retention step after completion of the purging step. . 3. The electric rice cooker according to claim 1, further comprising a blower passage closing means for closing the second blower passage when the rice cooking step or the transition to the heat retention step is completed. 4. The electric rice cooker according to claim 1, further comprising an air blow passage opening means for opening the second air blow passage at the time of shifting to the heat retention step after completion of the Murashi step. 5. The electric rice cooker according to claim 1, 2, 3 or 4, wherein the cooling air is supplied to the rice cooker side for a predetermined set time after completion of the purging process. vessel. 6. The supply of cooling air to the rice cooker side is configured to be performed until the temperature of the rice cooker drops to a predetermined set temperature. The electric rice cooker described in 4.