JP3849595B2 - Electric rice cooker - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
[0002]
The present invention relates to an electric rice cooker, and more particularly to an electric rice cooker configured to be able to suppress spillage during rice cooking.
[Prior art]
[0003]
As a conventionally known electric rice cooker, a rice cooker body configured to be able to take out the rice cooker freely, a lid body of the rice cooker body, and electromagnetic induction acting as a heating means for heating the rice cooker Some have a coil.
[0004]
In the case of the electric rice cooker having the above configuration, the rice cooker is heated by the electromagnetic induction coil according to the rice cooking characteristic curve at the time of rice cooking. For example, in the boiling maintaining step during rice cooking, FIG. As shown in (b), a method in which the electromagnetic induction coil is ON / OFF controlled so as to have a set temperature or set humidity has been frequently used.
[Problems to be solved by the invention]
[0005]
However, in the case of the control method described above, it is not possible to converge to the target set value, and for example, there arises a problem that spillage occurs due to overshoot during boiling maintenance control.
[0006]
Further, as a method for controlling the electromagnetic induction coil, a method in which a designer determines a fixed output value by experiment and controls based on the output value thus determined has been frequently used. In that case, since there is a solid difference in the electric rice cooker, if the control method is based on a specific output value, the solid difference cannot be absorbed, and thus accurate control may not be obtained.
[0007]
The present invention has been made in view of the above points, and aims to be able to perform boiling maintenance control at an optimum output in consideration of variations in product solids by using feedback control for boiling maintenance control. To do.
[Means for Solving the Problems]
[0008]
In invention of Claim 1, as a means for solving the said subject, the rice cooker main body comprised so that a rice cooker could be accommodated freely, the cover body of this rice cooker main body, and the said rice cooker were heated. In the electric rice cooker comprising an electromagnetic induction coil that acts as a heating means, a temperature sensor that detects the temperature of the rice cooker, and a humidity sensor that detects water vapor generated from the rice cooker, boiling is detected by the humidity sensor From this point, the output of the electromagnetic induction coil is increased or decreased depending on whether the detected humidity detected by the humidity sensor is lower or higher than the preset humidity, and the boiling state is maintained. Control means for performing feedback control that automatically adjusts is attached.
[0009]
By configuring as described above, after the boiling detection by the humidity sensor, the output of the electromagnetic induction coil is lower than the set humidity by comparing the detected humidity detected by the humidity sensor with a preset set humidity. Depending on whether it is high or low, feedback control is performed to automatically adjust to raise and lower and maintain the boiling state. Therefore, the output of the electromagnetic induction coil can be converged easily and quickly, and blowout can be effectively suppressed. In addition, the boiling can be maintained by the humidity detected from the humidity sensor regardless of the difference in individual products. Moreover, since the boiling detection and the boiling maintenance detection are performed by the humidity sensor, the boiling detection and the boiling maintenance detection can be accurately performed by one humidity sensor, and the feedback control can be performed reliably.
[0010]
In invention of Claim 2, as a means for solving the said subject, the rice cooker main body comprised so that a rice cooker can be accommodated freely, the cover body of this rice cooker main body, and the said rice cooker are heated. In an electric rice cooker comprising an electromagnetic induction coil that acts as a heating means, a temperature sensor that detects the temperature of the rice cooker, and a humidity sensor that detects water vapor generated from the rice cooker, boiling is detected by the temperature sensor From this point, the output of the electromagnetic induction coil is increased or decreased depending on whether the detected humidity detected by the humidity sensor is lower or higher than the preset humidity, and the boiling state is maintained. Thus, control means for performing feedback control for automatically adjusting is attached.
[0011]
With the above configuration, after the boiling detection by the temperature sensor, whether the output of the electromagnetic induction coil is lower than the set humidity compared with the preset humidity set by the humidity sensor. Depending on whether it is high or not, feedback control is performed that automatically adjusts to maintain the boiling state. Therefore, the output of the electromagnetic induction coil can be converged easily and quickly, and blowout can be effectively suppressed. In addition, the boiling can be maintained by the humidity detected from the humidity sensor regardless of the difference in individual products. Also, appropriate means can be used for the boiling detection and the boiling maintenance detection, respectively, and feedback control can be performed reliably.
DETAILED DESCRIPTION OF THE INVENTION
[0012]
Hereinafter, some preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.
[0013]
First Embodiment FIG. 1 shows an electric rice cooker according to a first embodiment of the present invention.
[0014]
As shown in FIG. 1, this electric rice cooker is made of a synthetic resin and configured to accommodate an outer case 4 constituting an outer peripheral surface and an inner peripheral surface and a rice cooker 5 made of a magnetic material. An electromagnetic induction coil that functions as a heating means for heating the rice cooker 5 that is located on the outer peripheral side of the protective frame 6 and the rice cooker body 1 constituted by the frame 6, the lid 2 of the rice cooker body 1, and the protective frame 6. 3.
[0015]
The outer case 4 includes a shoulder portion 4b serving as a connecting portion between a body portion 4a serving as a side peripheral surface of the rice cooker body 1 and an upper edge of the protective frame 6, and a bottom portion serving as a bottom portion of the rice cooker body 1. In the present embodiment, the body portion 4a and the shoulder portion 4b are constituted by an integrally molded product made of synthetic resin, and the bottom portion 4c is constituted separately. In some cases, the body portion 4a and the bottom portion 4c are formed of an integrally molded product made of synthetic resin, and the shoulder portion 4b is configured as a separate body.
[0016]
The upper part on the front side of the body part 4a in the outer case 4 is gently inclined, and an operation panel part 7 is provided in the part.
[0017]
On the bottom surface of the protective frame 6 and the back surface of the curved surface, annular electromagnetic induction coils 3 and 3 are respectively disposed. The electromagnetic induction coils 3 and 3 are positioned in a state of being sandwiched between a coil die 8 coupled to the lower surface of the central portion of the bottom surface of the protective frame 6 and extending radially along the protective frame 6 and the protective frame 6. ing. That is, the electromagnetic induction coils 3 and 3 have a shape that follows the outer peripheral surface shape of the protective frame 6. Reference numeral 9 denotes a temperature sensor that detects the temperature of the rice cooker 5 and acts as boiling detection means and boiling maintenance detection means, and 10 is a heat retaining heater.
[0018]
A synthetic resin shoulder ring 11 is attached to the inner peripheral edge of the shoulder portion 4b in the outer case 4 (in other words, the mouth of the rice cooker body 1) by forcible fitting. The metal heater ring 13 provided with the shoulder heater 12 is attached. As will be described later, the outer periphery of the vacuum double structure 21 in the lid 2 is pressed against the upper surface of the heater ring 13 (in other words, in contact with heat conduction) when the lid 2 is closed. It has become.
[0019]
A rice cooker cooling fan 15 is disposed at the center of the rear space portion 14 formed between the back side of the outer case 4 and the back side of the protective frame 6, and the rice cooker cooling fan. The cooling air from 15 is supplied to the air passage 17 formed between the shoulder 4b and the upper end of the protective frame 6 through the duct 16, and is passed between the rice cooker 5 and the protective frame 6 through the vent hole 18. The outer peripheral surface of the rice cooker 5 is cooled by being supplied to the gap S formed therebetween. The rice cooker 5 is cooled, for example, from the completion of cooking to the transition to the target heat retention temperature or at a predetermined time determined to be necessary during the heat retention process.
[0020]
On the other hand, the lid body 2 is pivotally supported by a rear part of the outer case shoulder 4b (that is, the opposite side of the operation panel section 7) via a hinge unit 19 so as to be openable and detachable, thereby forming an upper surface. It consists of a synthetic resin lid plate 20 and a vacuum double structure 21 forming the lower surface.
[0021]
An opening 22 into which a pressure adjusting cap 30 (to be described later) is detachably inserted is formed at a substantially central portion of the lid plate 20, and a screw cylinder 23 having an external thread on the outer periphery at the lip of the opening 22. Are integrally attached by high frequency welding.
[0022]
The vacuum double structure 21 is configured by forming a vacuum space 26 between two upper and lower doughnut-shaped metal plates 24 and 25 whose inner peripheral side and outer peripheral part are joined to each other. The inner peripheral side joining portion 21 a of the vacuum double structure 21 is covered with a seal member 27 and is inserted into the outer periphery of the screw cylinder 23. A vertical wall portion 25a is formed at a position from the outer periphery of the lower metal plate 25 constituting the vacuum double structure 21 to ensure strength and to be a mounting portion of a seal packing 36 to be described later.
[0023]
The vacuum double structure 21 is attached by screwing and tightening a screw ring 28 having an internal screw to the screw cylinder 23 in a state where the screw cylinder 23 is fitted and inserted into the inner peripheral side joining portion 21a. ing. That is, the vacuum double structure 21 can be attached to and detached from the upper plate 20 by screwing the screw ring 28.
[0024]
In addition, a pressure adjusting cylinder 29 is detachably attached in the screw cylinder 23, and an upper portion of the pressure adjusting cylinder 29 is covered by a pressure adjusting cap 30 that is detachably inserted into the opening 22. ing. Reference numeral 31 is a steam inlet to the pressure adjusting cylinder 29, 32 is a steam outlet from the pressure adjusting cylinder 29, 33 is a steam outlet in the pressure adjusting cap 30, 34 is a ball valve, and 35 is attached to the outer periphery of the pressure adjusting cylinder 29. Seal packing.
[0025]
By the way, in the present embodiment, the vacuum double structure 21 includes an upper metal plate 24 made of a material having poor heat conductivity (for example, stainless steel, titanium, etc.) and a material having good heat conductivity (for example, aluminum or aluminum). And a lower metal plate 25 made of an alloy or the like. Therefore, as the joining means for the upper and lower metal plates 24 and 25, a brazing capable of joining different metals is adopted.
[0026]
The outer peripheral portion of the lower metal plate 25 is a shoulder heater 12 (specifically, a heater ring) provided on the lip (that is, the outer case shoulder 4a) of the rice cooker body 1 when the lid 2 is closed. 13) to be brought into contact with each other so as to be able to conduct heat.
[0027]
A seal packing 36 that seals the opening of the rice cooker 5 when the lid 2 is closed is attached to the vertical wall 25 a of the lower metal plate 25 by a packing ring 37.
[0028]
In FIG. 1, the code | symbol 38 is a handle for carrying, 39 is a lock mechanism which hold | maintains the closed state of the cover body 2, and 40 is a heat insulating material.
[0029]
In the present embodiment, a humidity sensor 42 (not shown) for detecting water vapor is provided in the pressure adjustment cap 30, and the humidity sensor 42 is used as boiling detection means and boiling maintenance detection means.
[0030]
In the electric rice cooker having the above-described configuration, as shown in FIG. 2, the rice cooker temperature and humidity detected by the temperature sensor 9 and the humidity sensor 42 are input to the microcomputer 41 acting as control means. An arithmetic process is performed, and the result is output as a control signal to the electromagnetic induction coil 3, the heat retaining heater 10, and the shoulder heater 12, and the water absorption process, the rice cooking process, the steaming process, and the heat retaining process are executed according to the rice cooking characteristic curve shown in FIG. In the following, output control of the electromagnetic induction coil 3 in the boiling maintenance process in the rice cooking process will be described.
[0031]
The microcomputer 41 detects the output of the electromagnetic induction coil 3 by the humidity sensor 42 which also functions as a boiling maintenance detecting means so as to maintain the boiling state from the time when the boiling is detected by the humidity sensor 42 which functions as a boiling detection means. It has a function as a control means for feedback control based on the information (ie, detected humidity).
[0032]
Next, the boiling maintenance control in the electric rice cooker having the above configuration will be described in detail with reference to the flowchart shown in FIG.
[0033]
The detected humidity D of the humidity sensor 42 after the boiling is detected by the humidity sensor 42 in step S1 is input to the microcomputer 41. In step S2, the detected humidity D is set in advance (ie, the detected boiling humidity) Ds. A determination is made as to whether it is lower. Here, when an affirmative determination is made (that is, when it is determined that D <Ds), the process proceeds to step S3 to determine whether or not the output W of the electromagnetic induction coil 3 has reached the upper limit value Wmax. If a negative determination is made here (ie, if it is determined that W <Wmax), the output of the electromagnetic induction coil 3 is increased by 1 bit in step S4, and the process returns to step S2. If an affirmative determination is made in step S3 (ie, if W ≧ Wmax is determined), the process returns to step S2 without changing the output of the electromagnetic induction coil 3.
[0034]
On the other hand, if a negative determination is made in step S2, the process proceeds to step S5, and it is determined whether or not the detected humidity D is higher than a preset set humidity (ie, boiling detection humidity) Ds. Here, when an affirmative determination is made (that is, when it is determined that D> Ds), the process proceeds to step S6, where it is determined whether or not the output W of the electromagnetic induction coil 3 has reached the lower limit value Wmin. If a negative determination is made here (ie, if W> Wmin is determined), the output of the electromagnetic induction coil 3 is lowered by 1 bit in step S7, and the process returns to step S2. If an affirmative determination is made in step S6 (ie, if it is determined that W ≦ Wmin), the process returns to step S2 without changing the output of the electromagnetic induction coil 3.
[0035]
If a negative determination is made in step S5, it indicates that the detected humidity D has reached the set humidity (that is, the boiling detected humidity) Ds (that is, D = Ds). Then, the output of the electromagnetic induction coil 3 is maintained at the current state, and the process returns to step S2.
[0036]
In the above-described boiling maintenance control, feedback control for automatically adjusting the output of the electromagnetic induction coil 3 to an output that does not spill is performed based on information from the humidity sensor 42 (ie, the detected humidity D). Therefore, as shown in the time chart of FIG. 5, a stable output is finally obtained. And since it becomes control by automatic output adjustment of microcomputer 41 itself, even if there are variations in rice cookers and parts, the output of electromagnetic induction coil 3 can be stabilized.
[0037]
In the case of the present embodiment, during the feedback control, the feedback control is not performed when the output W of the electromagnetic induction coil 3 exceeds the output upper limit value Wmax and the output lower limit value Wmin of the electromagnetic induction coil 3. Therefore, even if there is a slight error in the information from the humidity sensor 42, it can withstand practical use.
[0038]
Furthermore, in the case of the present embodiment, since the humidity sensor 42 is used as the boiling detection means and the boiling maintenance detection means, boiling detection and boiling maintenance detection can be performed accurately, and feedback control can be performed reliably.
[0039]
Second Embodiment FIGS. 6, 7 and 8 show a block diagram of a control system, a flow chart and a time chart of boiling maintenance control in an electric rice cooker according to a second embodiment of the present invention. Yes.
[0040]
In this case, in addition to the temperature sensor 9 used as boiling detection means, a humidity sensor 42 for detecting water vapor is provided in the pressure adjustment cap 30, and the humidity sensor 42 is used as boiling maintenance detection means. As shown in FIG. 4, the rice cooker temperature and humidity detected by the temperature sensor 9 and the humidity sensor 42 are input to a microcomputer 41 that acts as control means, and the microcomputer 41 performs various arithmetic processes, and the result is a control signal. Are output to the electromagnetic induction coil 3, the heat retaining heater 10, and the shoulder heater 12. The microcomputer 41 detects the output of the electromagnetic induction coil 3 by the humidity sensor 42 acting as a boiling maintenance detecting means so as to maintain the boiling state from the time when the boiling is detected by the temperature sensor 9 acting as the boiling sensing means. It has a function as a control means for feedback control based on the information (ie, detected humidity). Since other configurations are the same as those in the first embodiment, the description thereof is omitted.
[0041]
Next, the boiling maintenance control in the electric rice cooker having the above configuration will be described in detail with reference to the flowchart shown in FIG.
[0042]
In step S1, the electromagnetic induction coil 3 is energized with 100% output, and in step S2, temperature information from the temperature sensor 9 (that is, rice cooker temperature) T and detected humidity D from the humidity sensor 42 are input to the microcomputer 41, In step S3, it is determined whether or not the rice cooker temperature T has reached a preset temperature (ie, boiling detection temperature) Ts. If an affirmative determination is made in step S4, the temperature from the humidity sensor 42 is determined. It is determined whether or not the detected humidity D is lower than a preset set humidity Ds. Here, when an affirmative determination is made (that is, when it is determined that D <Ds), the process proceeds to step S5 to determine whether or not the output W of the electromagnetic induction coil 3 has reached the upper limit value Wmax. If a negative determination is made here (ie, if it is determined that W <Wmax), the output of the electromagnetic induction coil 3 is increased by 1 bit in step S6, and the process returns to step S4. If an affirmative determination is made in step S5 (ie, if W ≧ Wmax is determined), the process returns to step S4 without changing the output of the electromagnetic induction coil 3.
[0043]
On the other hand, if a negative determination is made in step S4, the process proceeds to step S7, and it is determined whether or not the detected humidity D is higher than a preset set humidity (ie, boiling detection humidity) Ds. Here, when an affirmative determination is made (that is, when it is determined that D> Ds), the process proceeds to step S8, where it is determined whether or not the output W of the electromagnetic induction coil 3 has reached the lower limit value Wmin. If a negative determination is made here (ie, if it is determined that W> Wmin), the output of the electromagnetic induction coil 3 is lowered by one bit in step S9, and the process returns to step S4. If an affirmative determination is made in step S8 (ie, if W ≦ Wmin), the process returns to step S4 without changing the output of the electromagnetic induction coil 3.
[0044]
If a negative determination is made in step S7, it indicates that the detected humidity D has reached the set humidity (that is, the boiling detected humidity) Ds (that is, D = Ds). Then, the output of the electromagnetic induction coil 3 is maintained at the current state, and the process returns to step S4.
[0045]
In the above-described boiling maintenance control, after the boiling detection is performed by the temperature sensor 9, the output of the electromagnetic induction coil 3 is automatically converted to an output that does not spill based on the information from the humidity sensor 42 (ie, the detected humidity D). Therefore, as shown in the time chart of FIG. 8, a stable output is finally obtained. And since it becomes control by automatic output adjustment of microcomputer 41 itself, even if there are variations in rice cookers and parts, the output of electromagnetic induction coil 3 can be stabilized.
[0046]
In the case of the present embodiment, during the feedback control, the feedback control is not performed when the output W of the electromagnetic induction coil 3 exceeds the output upper limit value Wmax and the output lower limit value Wmin of the electromagnetic induction coil 3. Therefore, even if there is a slight error in the information from the humidity sensor 42, it can withstand practical use.
[0047]
Furthermore, in the case of the present embodiment, since the existing temperature sensor 9 is used as the boiling detection means and the humidity sensor 42 is used as the boiling maintenance detection means, each of the boiling detection and the boiling maintenance detection is appropriate. Thus, the feedback control can be performed more reliably.
【The invention's effect】
[0048]
According to invention of Claim 1, the rice cooker main body comprised so that rice cooker could be accommodated freely, the cover body of this rice cooker main body, and the electromagnetic induction which acts as a heating means which heats the said rice cooker In an electric rice cooker comprising a coil, a temperature sensor for detecting the temperature of the rice cooker, and a humidity sensor for detecting water vapor generated from the rice cooker, the electromagnetic induction from the time when boiling is detected by the humidity sensor Feedback that automatically adjusts the coil output so that the detected humidity detected by the humidity sensor is compared with a preset set humidity and raised or lowered depending on whether it is lower or higher than the set humidity to maintain the boiling state and attaching a control means for controlling, after the boiling detection by the humidity sensor, the output of the electromagnetic induction coil, the sensing humidity detected by the humidity sensor Because in comparison with the order set set humidity as feedback control to adjust automatically so that the maintain the raised and lowered to boil by higher or lower than the set humidity is performed, the electromagnetic induction coil output Can be easily and quickly converged, and there is an effect that blowout can be effectively suppressed. Moreover, there is an effect that the boiling can be maintained by the humidity detected from the humidity sensor regardless of the difference in individual products. Moreover, since the boiling detection and the boiling maintenance detection are performed by the humidity sensor, the boiling detection and the boiling maintenance detection can be accurately performed by one humidity sensor, and there is an effect that the feedback control can be surely performed. .
[0049]
According to invention of Claim 2, the rice cooker main body comprised so that rice cooker could be accommodated freely, the cover body of this rice cooker main body, and the electromagnetic induction which acts as a heating means which heats the said rice cooker In an electric rice cooker comprising a coil, a temperature sensor for detecting the temperature of the rice cooker, and a humidity sensor for detecting water vapor generated from the rice cooker, the electromagnetic induction from the time when boiling is detected by the temperature sensor Feedback that automatically adjusts the coil output so that the detected humidity detected by the humidity sensor is compared with a preset set humidity and raised or lowered depending on whether it is lower or higher than the set humidity to maintain the boiling state and attaching a control means for controlling, after the boiling detection by the temperature sensor, the output of the electromagnetic induction coil, advance detection humidity detected by the humidity sensor Because in comparison with the constant has been set humidity to automatically feedback controlled to adjust so as to maintain the raised and lowered to boil by either lower or higher than the set humidity is performed, the output of the electromagnetic induction coil It can be easily and quickly converged, and there is an effect that blowout can be effectively suppressed. Moreover, there is an effect that the boiling can be maintained by the humidity detected from the humidity sensor regardless of the difference in individual products. In addition, appropriate means can be used for the boiling detection and the boiling maintenance detection, respectively, and there is an effect that the feedback control can be performed reliably.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of an electric rice cooker according to a first embodiment of the present invention.
FIG. 2 is a block diagram of a control system in the electric rice cooker according to the first embodiment of the present invention.
FIG. 3 is a characteristic diagram showing rice cooking characteristics in the electric rice cooker according to the first embodiment of the present invention.
FIG. 4 is a flowchart showing the content of boiling maintenance control in the electric rice cooker according to the first embodiment of the present invention.
FIG. 5 is a time chart showing the content of boiling maintenance control in the electric rice cooker according to the first embodiment of the present invention.
FIG. 6 is a block diagram of a control system in an electric rice cooker according to a second embodiment of the present invention.
FIG. 7 is a flowchart showing the content of boiling maintenance control in the electric rice cooker according to the second embodiment of the present invention.
FIG. 8 is a time chart showing the contents of boiling maintenance control in the electric rice cooker according to the second embodiment of the present invention.
9A is a time chart showing the content of conventional boiling maintenance control, and FIG. 9B is a time chart showing output change of the electromagnetic induction coil at that time.
[Explanation of symbols]
1 is a rice cooker body, 2 is a lid, 3 is an electromagnetic induction coil, 5 is a rice cooker, 9 is a temperature sensor, 41 is a control means (microcomputer), and 42 is a humidity sensor.

Claims (2)

A rice cooker body configured to be able to take out the rice cooker freely, a lid body of the rice cooker body, an electromagnetic induction coil that acts as a heating means for heating the rice cooker, and a temperature of the cooker An electric rice cooker comprising a temperature sensor for detecting and a humidity sensor for detecting water vapor generated from the rice cooker, wherein the output of the electromagnetic induction coil is detected from the humidity sensor when boiling is detected by the humidity sensor. Control means for performing feedback control for automatically adjusting to maintain the boiling state by raising or lowering the detected humidity detected by the above in accordance with whether the detected humidity is lower or higher than the preset humidity is added. An electric rice cooker characterized by that. A rice cooker body configured to be able to take out the rice cooker freely, a lid body of the rice cooker body, an electromagnetic induction coil that acts as a heating means for heating the rice cooker, and a temperature of the cooker An electric rice cooker comprising a temperature sensor for detecting and a humidity sensor for detecting water vapor generated from the rice cooker, wherein the output of the electromagnetic induction coil is output from the humidity sensor when boiling is detected by the temperature sensor. A control means is provided for performing feedback control that automatically adjusts the detected humidity detected by the above to a lower or higher level depending on whether it is lower or higher than the preset humidity and to maintain the boiling state. An electric rice cooker characterized by

Images