JP2013085916A - Rice cooker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the following problems: in a conventional technology, rice bran odor remains on rice without being discharged and smell is deteriorated since air inside a pot is not discharged since steam is not generated when heating is off when performing heating control by PWM (Pulse Width Modulation), and in particular when heating the pot by high heating power by induction heating or the like, the heating power has to be lowered in order to perform heating so as to prevent boiling-over and scorching, and when the PWM is used in order to lower the heating power, ON time becomes short and OFF time becomes long and the smell of the rice is deteriorated.SOLUTION: A rice cooker is provided, which includes: a body 1; a pot 2 freely detachably housed inside the body 1; a heating coil 5 for heating the pot 2; a control means 8 for controlling the heating coil 5; and a heating and discharging means 8a for discharging the air inside the pot 2 by maintaining a boiling state inside the pot 2.

Description

  The present invention relates to a rice cooker used in general households, restaurants and the like.

  Conventionally, the rice cooking process of this kind of rice cooker has mainly been the water immersion process in which the rice absorbs water, the cooking process in which the temperature in the pan is raised and boiled at once, and the rice starch is gelatinized by maintaining the boiling. It consists of a boiling maintaining step for making it into rice and an uneven step for steaming the cooked rice to finish the inside of the pan uniformly, and the control method in each step is stored in the control means.

  In addition, conventionally, a steam cylinder for exhausting the air in the pan to the outside of the main body is provided, and in the cooking process and the boiling maintenance process, the pan by the heating means is heated. If it exceeds, steam will generate | occur | produce and the air in the said pan will be exhausted out of a main body. At this time, a rice cooker that improves the scent of rice by discharging odors such as bran odor is known (for example, see Patent Document 1).

  Moreover, the rice cooker which controls on / off control of the heating of the pan by the heating means using PWM (Pulse Width Modulation), and controls the heating power as an average of the whole cycle by changing the ratio of the on time and the off time. It is known (see, for example, Patent Document 2).

JP 2003-70629 A Japanese Patent No. 4045751

  However, in the above prior art, when performing heating control by PWM, steam is not generated when the heat is turned off, and the air in the pan is not exhausted, so the bran odor is not discharged and remains in the rice, which worsens the aroma. There was a problem.

  In particular, when heating the pan with high heating power such as induction heating, it is necessary to lower the heating power to prevent spilling and scorching, so when using PWM, the on time is short, the cutting time is long, There was a problem of worsening the scent of rice.

  This invention solves the said conventional subject, and aims at providing the rice cooker which improved the fragrance of rice and improved cooking performance.

  In order to solve the conventional problems, a rice cooker of the present invention includes a main body, a pan detachably accommodated in the main body, a heating means for heating the pan, and a control means for controlling the heating means. The heating and exhausting means for exhausting the air in the pan by maintaining the boiling state in the pan.

  Thereby, since the boiling state is maintained, the air in the pan is positively exhausted.

According to the present invention, the air in the pan can be positively exhausted, so that the scent of rice is improved,
The cooking performance of the rice cooker can be improved.

Side sectional view of the rice cooker in Embodiment 1 of the present invention. Rice cooking process diagram of rice cooker in Embodiment 1 of the present invention Comparison diagram of on / off time required to put the same average heating power in PWM of rice cooker in Embodiment 1 of the present invention

  According to a first aspect of the present invention, there is provided a main body, a pan detachably accommodated in the main body, a heating means for heating the pan, a control means for controlling the heating means, and steam in the pan outside the main body. And a heating / exhaust means for exhausting the air in the pan to improve the smell of rice by maintaining the boiling state in the pan.

  Thereby, since the air in the pan can be positively exhausted, the scent of rice can be improved and the cooking performance of the rice cooker can be improved.

  In the second invention, in particular, in the first invention, the heating power of the heating means is set to 500 to 900 W.

  When the heating power of the heating means is 500 W or less, the heating power becomes insufficient, and rice cooking performance cannot be brought out. Also, especially in the boiling maintenance process, if the heating means has a high heating power, spilling or scorching will occur, so the on / off control of heating is performed using PWM, and the ratio of on / off time is changed by changing the ratio of on / off time. However, when the heating power of the heating means is 900 W or more, there is a problem that the entry time is short, the cutting time is long, and the aroma of rice is deteriorated.

  According to the present invention, while ensuring the thermal power necessary for rice cooking, it is possible to prevent spilling and scorching, and to actively exhaust the air in the pan, so that the scent of rice is improved, the rice cooker Cooking performance can be improved.

  In a third aspect of the invention, in particular, in the first or second aspect of the invention, the heating and evacuating means is operated in a step where the pan becomes 90 ° C. or higher.

  When the pan is at 90 ° C. or higher, the water in the pan is in a boiling state or a state close thereto, and the water in the pan is heated at the time of heating, and steam is generated when the boiling point is exceeded. The air inside is exhausted outside the main body.

  According to the present invention, when steam is generated in the pan, the air in the pan can be positively exhausted, so that the aroma of rice can be improved and the cooking performance of the rice cooker can be improved. it can.

  In a fourth aspect of the present invention, in particular, in any one of the first to third aspects, the ratio of the on time to the heating on / off cycle by the heating and exhausting means is 70% or more.

  When performing heating on / off control using PWM, if the ratio of the on time to the heating on / off cycle is 70% or more, the generation of steam is maintained by the heat capacity of the pan. Or even if generation | occurrence | production of steam stops for a short time, since the next period heating starts immediately, odors, such as a bran odor, do not adhere to rice.

  According to the present invention, since the air in the pan can be positively exhausted, the scent of rice can be improved and the cooking performance of the rice cooker can be improved.

  In a fifth aspect of the present invention, in particular, in any one of the first to fourth aspects, the heating means includes a heating coil that heats the pan and an inverter that applies a high-frequency current to the heating coil.

  When induction heating the pan, only the pan is heated, so the temperature gradient of the temperature rise of the pan when heating is turned on and the temperature drop of the pan when heating is turned off compared to when heating with a sheathed heater or the like. growing. That is, when performing heating on / off control using PWM, there is a problem that the scent of rice is further deteriorated.

  According to the present invention, the air in the pan can be positively exhausted even when the pan is induction-heated, so that the scent of rice can be improved and the cooking performance of the rice cooker can be improved.

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

(Embodiment 1)
FIG. 1: shows the sectional side view of the rice cooker in Embodiment 1 of this invention.

  In FIG. 1, a main body 1 is formed in a substantially cylindrical shape having an upper surface opened, and includes a protective frame 10 that is a pot storage portion inside the main body 1, and is drawn on the inner peripheral surface in the protective frame 10. A pan 2 having a water level line is detachably disposed. A heating coil 5 for heating the pan 2 is provided outside the protective frame 10.

  The control means 8 controls the inverter 7 and heats the pan 2 by applying a high frequency current to the heating coil 5 which is a heating means. The heating power of the heating coil 5 is 700W.

  A lid 3 is attached to the upper part of the main body 1 so as to be freely opened and closed. The lid 3 is rotatably supported on the rear portion of the protective frame 10 via a hinge 3a and is urged by a rotating spring. At the other end of the lid 3, a hook button 1 a pivotally supported in front of the protective frame 10 is disposed to prevent the lid 3 from being opened. When the hook button 1a is fitted to the lid 3, the lid 3 is held by the hook button 1a without opening and is in a closed state.

  An inner lid 4 having a steam port 4b for discharging steam generated in the pan 2 during rice cooking and heat insulation is disposed at the lower portion of the lid 3, and the upper portion communicates with the outside of the main body through a steam tube port 11a. A cylindrical steam cylinder 11 is provided.

  A steam port packing 6 is disposed between the steam cylinder 11 and the inner lid 4 to prevent the steam from flowing into the lid 3. Further, an inner lid packing 4a that is in contact with the upper surface of the flange portion (not shown) of the pan 2 is disposed on the outer peripheral portion of the inner lid 4, and steam generated in the pan 2 during rice cooking and heat insulation is steamed. It prevents outflow from outside except 4b.

  The heating exhaust unit 8a uses the heating unit to heat the pan 2 so as to maintain the boiling state, and exhausts the air in the pan 2 to improve the smell of rice.

  The pan temperature detection means 9 can detect the temperature of the pan 2 by heat conduction in contact with the substantially central portion of the bottom of the pan 2. The lid temperature detection means 12 can contact the lid 3 and detect the temperature of the pan 2 by heat conduction.

  The operation display unit 13 receives an operation from the user and notifies the user of the state of the rice cooker.

  The main body 1, the lid 3, the protective frame 10, and the steam cylinder 11 have resin cases, the pan 2 has a metal pan such as iron or SUS, the inner lid 3 has a metal lid, and the inner lid packing 4 a and steam. The mouth packing 6 is a rubber packing, the heating coil 5 is a copper wire coil, the inverter 7 is a high frequency inverter, the control means 8 is a microcomputer, and the pan temperature detection means 9 and the lid temperature detection means 12 are The thermistor can be easily configured by using a touch panel for the operation display unit 13.

  About the rice cooker comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  FIG. 2 is a rice cooking process diagram of the rice cooker according to Embodiment 1 of the present invention.

  In FIG. 2, the rice cooking process includes a soaking process in which rice absorbs water, a cooking process in which the temperature in the pan is raised at a stroke, and a boiling process in which the rice starch is gelatinized by maintaining boiling and maintaining boiling. It consists of a process and an uneven process in which the cooked rice is steamed to finish the inside of the pan uniformly, and the control means in each process is stored in the control means 8.

  First, after a user puts a predetermined amount of rice and water into the pan 2 and sets it in the main body 1, an operation for starting rice cooking is performed using the operation display unit 13, and when the control means 8 accepts, the control means 8 is submerged. Start the process.

  The water immersion process is a process that allows the rice to be sufficiently gelatinized in the subsequent steps by immersing the rice in water at a temperature lower than the temperature at which the rice is gelatinized and preliminarily absorbing the rice. .

  The water immersion process is also a process of degrading starch with amylase contained in rice to produce glucose, thereby producing rice sweetness. For this reason, in a water immersion process, it controls so that the detection temperature of the pan temperature detection means 9 may be about 60 degreeC for predetermined time (for example, 20 minutes).

  That is, the control means detects the temperature by the pan temperature detecting means 9 and operates the inverter 7 to apply the high frequency current to the heating coil 5 to heat the pot 2 if it is 60 ° C. or less. If the detected temperature is 60 ° C. or higher, the inverter 7 is operated to stop the current application to the heating coil 5 and the heating of the pan 2 is stopped.

  When a predetermined time has elapsed from the start of the water immersion process, the process proceeds to the cooking process.

  In the cooking process, the pan 2 is heated until the temperature detected by the pan temperature detecting means 9 is close to the boiling point of water (for example, 100 ° C.). At this time, the amount of the cooking object, that is, the amount of cooked rice can be determined based on the difference in the temperature gradient of the detected temperature.

  When the temperature detected by the pan temperature detecting means 9 reaches a predetermined temperature, the process proceeds to the boiling maintenance step.

  The boiling maintaining step is a step of gelatinizing rice starch to raise the degree of gelatinization to about 50% to 60%. In the boiling maintenance process, the control means 8 operates the heating exhaust means in the process where the pot becomes 90 ° C. or higher so that the rice and water in the pot 2 maintain a boiling state while the pot 2 has water. The heating exhaust means 8a is operated, and the heating exhaust means 8a operates the inverter 7 to apply a high frequency current to the heating coil 5 to heat the pan 2.

At this time, the heating on / off control is performed using PWM, and the ratio of the on time to the off time is set to 70% or more.

  FIG. 3 is a diagram showing a comparison of turn-off time required for putting the same average heating power when heating is performed using PWM of the rice cooker in Embodiment 1 of the present invention when the heating power is 1200 W and 700 W. .

  When the heating power is 1200 W, the heating time is set to 50% and the cutting time is set to 50% with respect to the heating cycle of 16 seconds. On the other hand, when the heating power is 700 W, in order to obtain the same average heating power, the on-time is about 85% and the cut-off time is about 15%.

  That is, the heating time becomes longer as the heating coil 5 lowers the heating power for heating the pan 2, and the water in the pan 2 boils and steam is generated, so that the air in the pan 2 is exhausted. Can do. On the other hand, if the heating coil 5 excessively decreases the heating power for heating the pan 2 (about 500 W), the heating power becomes insufficient and the rice cooking performance cannot be brought out.

  Moreover, although boiling is maintained during heating-on, the generation of steam is maintained by the heat capacity of the pan 2 even if the heating is turned off. In addition, even if steam generation is interrupted for a short time, the next cycle of heating starts immediately, so no odor such as bran odor will adhere to the rice. The scent can be improved and the cooking performance of the rice cooker can be improved.

  When the water in the pot 2 is absorbed or evaporated due to this heating, the temperature of the pot 2 rises. When the temperature detected by the pan temperature detecting means 9 reaches a predetermined temperature (for example, 130 ° C.), the boiling maintenance process is terminated and the process proceeds to the unevenness process.

  The unevenness process is a process in which starch of rice is gelatinized to increase the degree of gelatinization to nearly 100%. In the spotting process, while preventing the bottom of the pot from scorching, the temperature of the rice is prevented from decreasing, and the rice in the pot 2 is homogenized by promoting gelatinization. In response to this, a plurality of times (for example, twice) are performed, and heating is turned on and off so that the temperature of the pan temperature detecting means 9 is maintained at a predetermined temperature (for example, 80 ° C.).

  In addition, although the heating exhaust means 8a can exhaust the air in the pan 2 positively by using it for a boiling maintenance process, especially the aroma of rice can be improved and the cooking performance of the rice cooker can be improved. , It may be used in other steps.

  In addition, although the heating power of the heating coil 5 was 700 W, the same effect is acquired even if it is either 500-900W.

  In addition, by heating at 700 W, it is possible to prevent an overheating state and the effect of reducing power consumption is also acquired.

  Since the present invention can positively exhaust the air in the pot, it can improve the scent of rice, improve the cooking performance of the rice cooker, and is useful for rice cookers used in ordinary homes, restaurants, etc. is there.

DESCRIPTION OF SYMBOLS 1 Main body 2 Pan 5 Heating coil 7 Inverter 8 Control means 8a Heating exhaust means 11 Steam cylinder

Claims (5)

The body,
A pan that is detachably stored in the main body;
Heating means for heating the pan;
Control means for controlling the heating means;
A steam cylinder for guiding the steam in the pan to the outside of the main body;
A rice cooker comprising heating and exhausting means for exhausting the air in the pan and improving the smell of rice by maintaining the boiling state in the pan. The rice cooker according to claim 1, wherein a heating power of the heating means is 500 to 900W. The rice cooker according to claim 1 or 2, wherein the heating and exhausting unit is operated in a step in which the pan becomes 90 ° C or higher. The rice cooker according to any one of claims 1 to 3, wherein a ratio of on time to a heating on / off cycle by the heating and exhausting means is 70% or more. The rice cooker according to any one of claims 1 to 4, wherein the heating means includes a heating coil that heats the pan and an inverter that applies a high-frequency current to the heating coil.