JP6714794B2 - rice cooker - Google Patents

Description

The present invention relates to a rice cooker that cooks rice and water to be cooked in a short time in a delicious and delicious manner.

Generally, this type of rice cooker, as shown in Patent Document 1, has a heating means for heating an object to be cooked such as rice and water in a pan, a decompression means for decompressing the object to be cooked below atmospheric pressure, and a cooked object. Equipped with a pressurizing means for pressurizing the food to a pressure higher than the atmospheric pressure, and a control means for heating the cooked food so that the inside of the pan is maintained at the set temperature and the set pressure during the set time. The control means controls the heating means and the pressure reducing means or the pressure applying means to cook rice.

In addition to the standard rice cooking course in which the rice is cooked in about 50 minutes, Patent Document 2 has a high-speed rice cooking course in which the rice is cooked in about 30 minutes by shortening the time of the hitashi and Murashi strokes compared to the standard rice cooking course. A rice cooker provided is disclosed.

JP, 2014-50757, A JP, 2005-111037, A

Here, the relationship between the rice cooking time and the meal preparation time performed by the rice cooker will be described with reference to FIG. 7. FIG. 7 shows the result of a survey on the dinner preparation time in which it is estimated that the rice cooker is most used among the three meals, and the dinner preparation time is 46 to 60 minutes at the maximum. However, the typical standard rice cooking course of the conventional rice cooker is around 60 minutes, and if rice preparation is started at the same time as dinner preparation, only 20% of people whose dinner preparation time exceeds 60 minutes will be ready for dinner. However, it was found that the rice was not cooked and I didn't eat the freshly cooked rice. On the other hand, some conventional rice cookers are equipped with a "fast-cooking" high-speed rice cooking course in which rice is cooked in about 30 minutes. In this case, 85% of people who have more than 30 minutes to prepare dinner When the dinner is ready, the rice is cooked and you can eat the freshly cooked rice.

However, if the speed of cooking rice is emphasized, the deliciousness of rice is sacrificed. Conversely, if the taste of rice is emphasized, the quick cooking time is sacrificed. Therefore, in the past, it was a compromise choice between choosing the deliciousness of the rice or otherwise choosing the speed of the cooked rice.

In view of the above problems, it is an object of the present invention to provide a rice cooker capable of eating delicious rice at an earlier rice cooking time than before.

The rice cooker according to claim 1 of the present invention is a pot for accommodating an object to be cooked therein, a lid for sealing the inside of the pot, a heating means for heating rice and water as the object to be cooked, and the cooked object. Decompression means for decompressing an object to a state lower than atmospheric pressure, pressurizing means for pressurizing the object to be cooked to a state higher than atmospheric pressure, and control for heating the cooking object by controlling the heating means. Means, the decompression means comprises a decompression drive source and a first valve for opening and closing a communicating path between the inside of the pot and the decompression drive source, and the lid is for the pot. A steam passage for discharging the steam generated inside to the outside of the rice cooker is provided, the pressurizing means is provided with a second valve for opening and closing the steam passage, and the control means is a soaker for promoting water absorption of the rice. Throughout the entire period of the stroke, the path is opened and the decompression drive source is continuously operated to bring the cooked material into a depressurized state lower than the atmospheric pressure, and in the heating step following the hot water stroke, the cooked material is With the depressurized state until boiling in a depressurized state, the operation of the second valve is controlled so as to close the steam passage, and when the soaking stroke is completed and the heating step is performed, the soaking step is performed by the heating means. While heating the food to be cooked more strongly than the stroke, the operation of the first valve is controlled so as to close the path, and the drive of the decompression drive source is stopped, and the food to be cooked is decompressed in the heating stroke. When it is determined that the material has boiled, the operation of the second valve is controlled so that the steam passage is temporarily opened and then closed, and the cooked object is pressurized from the depressurized state to a pressure higher than atmospheric pressure. It is characterized in that it is configured to switch all at once .

Further, in the rice cooker according to claim 2 of the present invention, even when the control means determines that the food to be cooked has boiled in a depressurized state in the heating process, the first valve is continuously closed to close the path. The operation is controlled so that the driving of the pressure reducing drive source is stopped .

According to the invention of claim 1, even in the heating step of heating the cooked material weaker than the hot water stroke, the cooked material is heated to a degree that promotes water absorption of rice. The object to be cooked is kept in a reduced pressure state by the pressure reducing means until it boils in a reduced pressure state of not higher than 0°C. Therefore, it is possible to boil the cooked material at a gelatinization temperature of 60°C to 100°C, which allows the rice to absorb water to the core in a short time while making the rice dance, which leads to a faster cooking time than before. It becomes possible to eat delicious rice. In addition, in the heating process, the food to be cooked is switched from depressurization to pressurization all at once, and by applying a pressure shock, the food to be cooked is boiled under pressure to reach the optimum gelatinization temperature of rice, for example, 105°C. The balance between toughness and tenacity can be secured, the rice can be gelatinized evenly to the core, and more delicious rice can be eaten.

According to the invention of claim 2, the operation of the pressure regulating valve 26 is controlled while the driving of the pressure reducing pump 31 is stopped, and the steam passage 25 is temporarily opened and then closed. It is possible to switch the cooking target from reduced pressure to pressurization all at once, and to apply a pressure shock to the cooking target .

It is the whole rice cooker sectional view in one example of the present invention. It is a block diagram which shows an electric structure same as the above. 3 is a timing chart showing changes in the temperature detected by the inner pot temperature sensor, the temperature detected by the lid temperature sensor, the pressure detected in the inner pot, and the voltage input to the heating means. It is a figure explaining the graph which shows the vapor pressure curve of water, and the operating state inside an inner pot same as the above. It is a figure showing the result of a taste test about the rice cooker of a present Example, and the conventional rice cooker. It is a figure showing the result of the taste test different from FIG. It is a figure explaining the survey result of the preparation time of dinner.

Hereinafter, embodiments of the rice cooker according to the present invention will be described with reference to the accompanying drawings.

The overall structure of the rice cooker will be described with reference to FIG. 1. 1 is a bottomed main body, 2 is a lid that covers the top opening of the main body 1 in an openable and closable manner. It is formed. A hinge 3 serving as a connecting portion with the main body 1 is provided at the rear portion of the lid 2, and the hook button 4 provided on the upper surface of the front portion of the lid 2 is pushed to operate the engagement between the lid 2 and the main body 1. The engagement is released and the lid 2 is automatically opened with the hinge 3 as the center of rotation.

The main body 1 is formed with a bottomed cylindrical pan container 5 made of a non-magnetic material or the like. The pan container 5 serves as a bottomed cylindrical pan for containing cooked items such as rice and water. The inner pot 6 is detachably provided. The inner pot 6 has a so-called round pot shape in which the side surface is curved in an R shape and the central body has a larger area than the upper end opening. An annular flange portion 7 is formed. The flange portion 7 is placed on the upper surface of the pan container 5 when the pan 6 is housed in the pan container 5, and a gap is formed between the pan container 5 and the pan 6 in the inner pot. 6 is suspended from the pan container 5. The inner pot 6 here is constructed by joining a heating element 9 made of a magnetic metal material such as ferritic stainless steel to the outer surface of a base material 8 mainly made of aluminum having good thermal conductivity.

Reference numeral 11 is a heating coil for heating the heating element 9 of the inner pot 6 by electromagnetic induction. The heating coil 11 is formed by spirally winding a litz wire, which is a conductor, facing the heating element 9 of the inner pot 6. As a result, when a high-frequency current is supplied to the heating coil 11, the heating element 9 of the inner pot 6 generates heat due to the alternating magnetic field generated from the heating coil 11, and the cooker in the inner pot 6 and hence the inner pot 6 is cooked during rice cooking or heat retention. Is heated.

An inner pot temperature sensor 12 as an inner pot temperature detecting means is arranged at an opening provided at the center of the bottom of the pan container 5 so as to elastically contact the outer bottom of the inner pot 6. The inner pot temperature sensor 12 detects the temperature of the inner pot 6, and is mainly configured to control the heating temperature of the bottom portion of the inner pot 6 by the heating coil 11.

On the upper surface of the lid 2, in addition to the hook button 4 as the lid opening operation body, the operation panel 17 as a panel including the display unit 15 and the operation unit 16 and the inside of the inner pot 6 due to heating of the food to be cooked. A steam port 19 and the like for discharging the generated steam to the outside of the rice cooker are provided, respectively. An inner lid assembly 21 as a lower member of the lid 2 is arranged below the lid 2. The inner lid assembly 21 includes an inner lid 22 made of a metal material having a disk shape having substantially the same diameter as the upper opening of the inner pot 6, and the inner lid 6 for sealing the inner pot 6 and the inner lid 22. A lid packing 23 as an elastic member provided on the entire outer circumference of the lid 22 and a pressure adjusting portion 24 for adjusting the internal pressure of the inner pot 6 are provided. The lid packing 23 formed in an annular shape contacts the upper surface of the flange portion 7 of the inner pot 6 to close the gap between the inner pot 6 and the inner lid 22 when the lid 2 is closed and the lid is closed. The steam generated from the kettle 6 is sealed. Further, the steam port 19 and the pressure adjusting unit 24 communicate with each other inside the lid body 2, and the steam generated in the inner pot 6 is discharged from the steam port 19 to the outside by the steam port 19 and the pressure adjusting unit 24. A vapor exhaust mechanism is formed.

The pressure regulating unit 24 is provided with a pressure regulating valve 26 that opens and closes a steam passage 25 between the inside of the inner pot 6 and the steam port 19. The pressure regulating valve 26 is ball-shaped, and is mounted on a valve seat 28 mounted in a substantially central portion of the inner lid 22 in cooperation with a solenoid 27 provided inside the lid 2. The valve seat 28 is provided with a communication hole 29 opened and closed by the pressure regulating valve 26 in the middle of the steam passage 25. When the solenoid 27 is in the non-energized state, its tip is held in the advanced position, and the pressure regulating valve 26 is opened. By retreating from the communication hole 29 of 28, the steam passage 25 is opened so that the same pressure is obtained inside and outside the inner pot 6, while the solenoid 27 is energized, the tip portion thereof is retracted and the pressure regulating valve 26 is opened. By rolling in the communication hole 29 of the valve seat 28 by its own weight, the communication hole 29 is closed and pressure is applied to the inside of the inner pot 6. In this state, when the pressure inside the inner pot 6 reaches a predetermined pressure higher than the atmospheric pressure (for example, 1.2 atm: 1 atm=101325 Pa), the pressure regulating valve 26 opens the communication hole 29 against its own weight, Adjust so that no further pressure is applied to the inside of the shuttle 6. That is, the pressure adjusting unit 24 here has a function as a pressurizing unit that pressurizes the food to be cooked inside the inner pot 6 to a state higher than the atmospheric pressure when the solenoid 27 is energized.

Reference numeral 31 is a decompression means provided for lowering the inside of the inner pot 6 below the normal atmospheric pressure with the lid 2 closed to the main body 1. The depressurizing means 31 has a tubular path (which communicates between the depressurizing pump 32 and the interior of the inner pot 6 inside the lid 2 in addition to the depressurizing pump 32 as a depressurizing drive source provided on the rear portion of the lid 2. (Not shown) and an electromagnetic valve 33 (see FIG. 2) that opens and closes the path. In this embodiment, the two pressure reducing pumps 32 are provided inside the lid 2, but the pressure reducing pumps 32 may be provided inside the main body 1, and the number thereof is not limited to two. As an example, when one decompression pump 32 is operated, the inside of the sealed inner pot 6 is decompressed to 0.6 atm, and when the two decompression pumps 32 connected in series are operated, the sealed inside is closed. The pressure inside the kettle 6 is reduced to 0.4 atmosphere.

In this embodiment, when the inner pot 6 is housed in the pan container 5 and the lid 2 is closed, the solenoid 27 is energized to activate the pressure reducing pump 32 from the state in which the pressure regulating valve 26 blocks the communication hole 29. The path is opened by the electromagnetic valve 33, the air inside the inner pot 6 is discharged to the outside of the main body 1 through the path and the pressure reducing pump 32, and the pressure inside the sealed inner pot 6 is reduced. When the pressure inside the inner pot 6 falls below the atmospheric pressure by a certain value, the operation of the decompression pump 32 is stopped, the path is closed by the solenoid valve 33, and the inside of the inner pot 6 is kept in a depressurized state. There is. Further, when returning the inside of the inner pot 6 to the same pressure as the outside air from the depressurized state, the operation of the depressurizing pump 32 is stopped and the path is opened by the solenoid valve 33. That is, the depressurizing means 31 in the present embodiment also serves as a pressure returning means for returning the inside of the inner pot 6 from the depressurized state to the same pressure as the outside air.

In order to heat the inner pot 6, in addition to the heating coil 11 that mainly heats the bottom of the inner pot 6 from the lower side surface, the side heater 35 that mainly heats the upper side of the inner pot 6, It is arranged on the outer surface upper part of the pan container 5. Further, inside the lid 2, a lid heater 36 as a lid heating means for heating the inner lid 22 and a thermistor type lid temperature sensor 37 for controlling the temperature of the inner lid 22 by the lid heater 36 are respectively provided. ..

Reference numeral 41 is a control unit provided inside the main body 1 at the rear side thereof and configured by mounting a microcomputer or the like on a substrate. The control means 41 includes a heating element 42 for driving the heating coil 11 and the like.

Next, the control system of the control means 41 will be described with reference to FIG. In the figure, the control means 41 receives the respective temperature detection signals from the inner pot temperature sensor 12 and the lid temperature sensor 37 and the operation signal from the operating section 16, and heats the inner pot 6 at the time of rice cooking and heat retention. a coil 11 and the side heater 35, and controls each of the lid heater 36 for heating the lid 2, and a solenoid 27 for moving the pressure regulating valve 26 described above, and vacuum pump 32, respectively control the operation of the solenoid valve 33, further Controls the display on the display unit 15. In particular, the control means 41 of the present embodiment mainly controls the heating coil 11 based on the temperature detected by the inner pot temperature sensor 12 to control the temperature of the bottom of the inner pot 6, and based on the detected temperature of the lid temperature sensor 37. The lid heater 36 is mainly controlled to control the temperature of the inner lid 22. The heating coil 11, the lid heater 36, and the side heater 35 described above correspond to a heating unit 44 that heats the food to be cooked in the inner pot 6.

As a function on the control sequence of the program stored in the storage means 46, the control means 41 receives an instruction to start cooking rice from the operation section 16, and accelerates the water absorption of the rice put into the inner pot 6, and the cover. Heating to raise the temperature of the cooked food to boiling in a short time, boiling detection to detect boiling of the cooked food, continuation of boiling to keep the cooked food in a boiling state, and dry cooked food to the cooked food. A rice-cooking control means 51 for heating the rice in the inner pot 6 to a desired pressure by sequentially performing each step of cooking and cooking and maintaining the temperature at a high temperature that does not scorched rice. , A heat retention control means 52 for controlling the rice in the inner pot 6 to maintain a predetermined heat retention temperature.

In particular, the rice cooking control means 51 of the present embodiment brings the cooked food in the inner pot 6 into a depressurized state lower than atmospheric pressure from the hot water stroke until the cooked material boils in the depressurized state even in the heating stroke following the hot water stroke. After the depressurized state is continuously maintained, when the cooked object boils in the depressurized state, the cooked object in the inner pot 6 is switched from the depressurized state to the pressurized state higher than the atmospheric pressure all at once, and the pressure is applied to the cooked object. It has a function as a pressure switching control means 54 for controlling the solenoid 27, the pressure reducing means 31, and the heating means 44 so as to give a shock. The pressure switching control means 54 detects whether or not the food to be cooked inside the inner pot 6 boiled under reduced pressure, and the detected temperature of the inner pot 6 detected by the inner pot temperature sensor 12 reaches 100° C. which is a predetermined temperature. However, as another method, it is also possible to use various detecting means other than the inner pot temperature sensor 12 to judge whether or not the food to be cooked has boiled under reduced pressure.

Next, the operation of the rice cooker having the above configuration will be described with reference to FIGS. 3 and 4. Note that FIG. 3 shows the temperature Ta detected by the inner pot temperature sensor 12, the detected temperature Tb by the lid temperature sensor 37, the detected pressure P in the inner pot 6, and the voltage input to the heating means 44 after the rice cooking is started. FIG. 4 is a timing chart showing a transition of V, and FIG. 4 is a graph showing a vapor pressure curve S of water and an operation state inside the inner pot 6 associated therewith.

First, the operation at the time of rice cooking in this embodiment will be described. After rice and water are put in the inner pot 6 as the food to be cooked and set in the pan container 5 of the main body 1, the lid 2 is closed and the operating body is closed. When, for example, the rice cooking key 16 is operated, rice cooking is started by the rice cooking control means 51 incorporated in the control means 41. Here, the rice cooking control means 51 disconnects the heating coil 11 and the side heater 35 based on the temperature detection of the bottom portion of the inner pot 6 by the inner pot temperature sensor 12 in order to promote the water absorption of the rice in the inner pot 6. Electricity control is performed to heat the bottom portion and the side surface portion of the inner pot 6 respectively, and the hot water stroke in which the water temperature in the inner pot 6 is maintained at about 45 to 60° C. for 3 minutes is performed.

Further, during this step, the pressure switching control means 54 incorporated in the rice cooking control means 51 controls the solenoid 27, the decompression pump 32, and the electromagnetic so that the pressure in the inner pot 6 becomes a depressurized state lower than the atmospheric pressure. The operation of the valve 33 is controlled respectively. Specifically, when the pressure switching control means 54 starts the expansion stroke, the solenoid 27 is switched from the non-energized state to the energized state, and the pressure regulating valve 26 closes the communication hole 29 of the steam passage 25. In this state, in order to discharge the air from the inside of the closed inner pot 6 through the depressurizing means 31, the route from the inside of the inner pot 6 to the depressurization pump 32 is maintained for the entire duration of the hitting stroke (3 minutes in this example). The operation of the solenoid valve 33 is controlled so as to be opened, and one or a plurality of decompression pumps 32 are continuously operated to evacuate the air inside the inner pot 6 by the decompression pump 32. It should be noted that while the decompression pump 32 is in operation, a message to that effect may be displayed on the display unit 15 so that the user can know that the inside of the inner pot 6 is being decompressed.

In this way, the pressure switch control means 54 maintains the inside of the inner pot 6 in a depressurized state during the hitting stroke. Therefore, it is possible to allow the rice to absorb water sufficiently inside the inner pot 6 at the time of dipping.

After that, when the hot-stroke process for a predetermined time is completed and the process goes to the next heating process, the rice cooking control means 51 continuously energizes the heating coil 11 and the side heaters 35, so that cooking inside the inner pot 6 is performed rather than the hot-water process. Heat the food strongly and raise the temperature of the food to boiling in a short time. Here, the pressure switching control means 54 stops the drive of the decompression pump 32 at the time of the heating stroke so as to maintain the inside of the inner pot 6 at a depressurized state lower than the atmospheric pressure continuously from the hit stroke, while stopping the driving of the depressurization pump 32. The operation of the solenoid valve 33 is controlled so as to close the path from the inside of the shuttle 6 to the decompression pump 32. Therefore, even after the transition to the heating process, the pressure inside the inner pot 6 gradually rises due to heating and slow leak to the inner pot 6, but for a while, the depressurizing pump 32 is operated in a pressurizing process with large power consumption. The depressurized state can be maintained without operating.

In this way, the food to be cooked inside the inner pot 6 is kept in a depressurized state even after the soaking step, so that the water boils at a temperature of 100° C. or less during the heating step. As shown in the graph of the vapor pressure curve S in FIG. 4, when the pressure inside the inner pot 2 is 0.2 atm, the water boils at about 60° C., and when the pressure inside the inner pot 6 is 0.4 atm, the water is about When boiling at 80°C and the pressure inside the inner pot 6 is 0.6 atm, water boils at about 88°C, so the cooked material is boiled under reduced pressure at 60°C to 100°C, which is the gelatinization temperature of rice. By so doing, rice can be fluttered by the bubbles at the time of boiling and uneven heating can be eliminated. In addition, the cooked material can be depressurized to allow the rice core to absorb water in a short time.

After that, the pressure switching control means 54 takes in the temperature detection signal from the inner pot temperature sensor 12 during the heating process, and when the temperature detected at the bottom of the inner pot 6 reaches 100° C. which is the predetermined temperature, the inside of the inner pot 6 is reached. It is determined that the cooking target boiled under reduced pressure, the path from the inner pot 6 to the decompression pump 32 is closed, the solenoid 27 is temporarily de-energized without operating the decompression pump 32, and the pressure regulating valve 26 is retracted from the communication hole 29. As a result, the steam passage 25 is in an open state in which the inside and outside of the inner pot 6 are communicated without being hermetically closed, and the inner pot 6 immediately returns to the same atmospheric pressure as the outside air. After that, when the solenoid 27 is switched to the energized state in a short time and the inside of the inner pot 6 is closed again, the food to be cooked inside the inner pot 6 is continuously heated by the strong heating of the object to be cooked inside the inner pot 6. Is pressurized to reach atmospheric pressure or more, eg, 1.2 atmospheric pressure, and the food to be cooked can be boiled under the pressure.

In this way, when the pressure switching control means 54 determines that the food to be cooked inside the inner pot 6 has boiled in the depressurized state during the heating process, it switches the inner pot 6 from the depressurized state to the pressurized state higher than the atmospheric pressure all at once. In order to apply a pressure shock to the food to be cooked, the operation of the solenoid 27 and by extension the pressure regulating valve 26 constituting the pressure regulating section 24 is controlled to temporarily open the steam passage 25. As a result, as shown in the graph of vapor pressure curve S in FIG. 3, when the cooked material is boiled to 105° C. (at 1.2 atm) which is the optimum temperature for gelatinizing rice under pressure, It is possible to secure the balance between toughness and stickiness and evenly gelatinize the rice to the core.

In the subsequent heating step, the rice cooking control means 51 causes the temperature detected by the inner pot temperature sensor 12 to reach a predetermined temperature, for example, 90° C. or higher, and in addition, the temperature detected by the lid temperature sensor 37 also reaches a predetermined temperature, for example, 90° C. If it becomes above, it will transfer to the boiling detection process which detects boiling of the to-be-cooked object in the pressurization state. In the boiling detection process, the heating coil 11 and the side heater 35 are continuously energized to strongly heat the food to be cooked inside the inner pot 6, while the inclination of the temperature detected by the lid temperature sensor 37 (detected at a predetermined time). How much the temperature rises) is calculated. When the inclination of the detected temperature becomes a certain value or less and stabilizes, it is determined that the food to be cooked in the inner pot 6 has boiled under pressure, and the process continues to the boiling continuation process.

When shifting to the boiling continuation process, the rice cooking control means 51 causes the lid heater 36 to start lid heating. The lid heating here is controlled by the temperature detected by the lid temperature sensor 37 so that the temperature of the inner lid 22 becomes 100°C. Further, when shifting to the boiling continuation step, the rice cooking control means 51 periodically turns on and off the solenoid 27.

Then, when the temperature detected by the inner pot temperature sensor 12 at the bottom of the inner pot 6 causes a predetermined temperature rise, the rice cooking control means 51 shifts from the boiling continuation step to the cooking step, where the inner pot temperature sensor 12 detects. When the temperature reaches a predetermined dry-up temperature, the cooking of the food to be cooked inside the inner pot 6 is detected, and the process shifts to the purging process. During the unevenness, the lid heater 36 is turned off by temperature control by the temperature detected by the lid temperature sensor 37 to prevent the dew on the inner lid 22 from being exposed, and the rice in the inner pot 6 is heated to a high temperature (98%). The temperature of the bottom of the inner pot 6 is controlled so that the temperature of the inner pot 6 is maintained at 100°C. The purging is continued for a predetermined time (for example, 12 minutes), and when the purging is completed, the heat retention control means 52 shifts to heat retention.

As shown in the timing chart of FIG. 3, with the above-described rice cooking control means 51 of the embodiment, the rice cooking heating by the rice cooking control means 51 is shortened to 30 minutes in the case of three-cooked rice from the start of hitoshi to the end of purple. It Although the conventional high-speed rice cooking course takes about 30 minutes to cook rice, it sacrifices the deliciousness of the rice. Also, although the standard rice cooking course produces delicious rice, it takes about 60 minutes to cook rice. In that respect, the rice cooker of the present embodiment devises a method of heating and pressure for the food to be cooked inside the inner pot 6 during the period from the hitting stroke to the heating stroke, so that the rice cooker can quickly cook rice like a high-speed rice cooking course. In time, you can finish delicious rice like a standard rice cooking course. Therefore, there is no need to select either the high-speed rice cooking course or the standard rice cooking course as in the past, and the operation of the operation unit 16 becomes easy to understand, and you can eat fast and delicious rice at any time in time for the dinner preparation period. It becomes possible to do.

Next, the results of the taste test of the rice cooker of this example and the conventional rice cooker will be described with reference to FIGS. 5 and 6.

The inventors of the present application, by the taste tester, cooked rice with the rice cooker of the above-mentioned example, and five conventional rice cookers (hereinafter, five rice cookers are referred to as “ready-made product A”, “ready-made product B”, A comparative test of taste was performed using "off-the-shelf C", "off-the-shelf D", and "off-the-shelf E" rice. In this comparative test, the taste tester was asked to try the rice cooked with the above-mentioned rice cooker, and the rice cooking time and the taste evaluation data of 3 go rices (the evaluation items were simply tasty or favorite) Collected. As the sample rice, shiibutsubuki was used, and in the ready-made products A to E, rice was cooked in a typical rice cooking course of each rice cooker. Taste testers consisted of 10 men and women, 20 people in total, and tasted "immediately after cooking" rice after cooking and so-called "cold rice" after a predetermined time in blinds.

The taste test results in FIG. 5 show a relative evaluation of how much taste is better than the rice cooked with the conventional ready-made product A, which is the evaluation standard, and the taste, and the average of the evaluations of 20 taste testers. Are indicated by points. The evaluation is rated in 3 levels, both for likes and dislikes, and "equivalent" is evaluated with 0 point. As a result, in the case of "immediately after cooking", the rice cooked in the rice cooker of the above-mentioned example was the most delicious and preferred, and the "cold rice" was the same as the rice cooked with the ready-made food A. , The result was delicious and tasted better than the rice cooked with other ready-made products B to E. Also, the rice cooking time of 3 go is as short as 30 minutes in the rice cooker of the above-mentioned example, and from the table of FIG. 7 described above, 85% of people can prepare rice even if rice is cooked at the same time when preparation for dinner is started. It is possible to eat freshly cooked rice with the food. From this, it is confirmed that the rice cooker of the above-described embodiment can cook rice that is as delicious as or better than the ready-made products A to E, and can cook rice much faster than the ready-made products A to E. did it.

The taste test result of FIG. 6 simply shows an absolute evaluation of whether it is delicious or favorite, and the average of the evaluations of 20 taste testers is shown by points. The evaluation is rated in 3 levels, both for likes and dislikes, and "equivalent" is evaluated with 0 point. As a result, for both the "immediately cooked" rice and the "cold rice", the rice cooked with the rice cooker of the above-mentioned example was the most delicious and preferred. From this, it was confirmed that the rice cooker of the above-mentioned example can cook more delicious rice as compared with the ready-made products A to E, and can cook rice much faster than the ready-made products A to E.

From the results of these taste tests, cooker of the embodiment than ready-made A-E, it was found that the superiority is obtained in both points of fast goodness and cooking taste.

As described above, in the rice cooker of the present embodiment, the heating means 44 for heating the rice and water contained in the inner pot 6 serving as a pan to be cooked, and decompressing the cooked food to a state lower than atmospheric pressure. The depressurizing means 31 for activating the water absorption of rice and the decompression state of the cooked food from atmospheric pressure to lower the atmospheric pressure, and the depressurized state is maintained until the cooked material boils in the depressurized state in the heating process following the dipping stroke. As described above, the heating means 44 and the decompression means 31 are controlled, and the control means 41 for heating the cooked material to rice with a desired pressure is provided.

In such a configuration, in the heating step of heating the cooked material weakly to the extent that it promotes water absorption of rice, and subsequently in the heating step of heating the cooked material more strongly than the dipping step, the cooked material has a temperature of 100°C or lower. The object to be cooked is kept in the reduced pressure state by the pressure reducing means 31 until it boils in the reduced pressure state. Therefore, it is possible to boil the cooked material at a gelatinization temperature of 60°C to 100°C, which allows the rice to absorb water to the core in a short time while making the rice dance, which leads to a faster cooking time than before. It becomes possible to eat delicious rice.

Further, the rice cooker of the present embodiment is provided with a pressure regulating valve 26 for interlocking with the solenoid 27 to open or close the inside and outside of the inner pot 6 as a pressurizing means for pressurizing the food to be cooked to a state higher than atmospheric pressure. A control unit 41 is further provided with a pressure adjusting unit 24 so that, after the food to be cooked inside the inner pot 6 boils in a depressurized state during the heating process, the food to be cooked is switched from the depressurized state to a pressurized state higher than atmospheric pressure. Is composed of.

By configuring in this way, the cooking target is switched from depressurization to pressurization at once in the heating process, and by applying a pressure shock, the cooking target is boiled under pressure to the optimum gelatinization temperature of rice, for example, 105°C. As a result, the balance between hardness and stickiness of the rice can be secured, the rice can be gelatinized evenly to the core, and it becomes possible to eat delicious rice.

It should be noted that the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention. The set value of pressure and the set time of the pressure in the embodiment are merely examples, and may be appropriately changed according to the specifications of each rice cooker.

2 Lid 6 Inner pot (pot)
24 Pressure regulator (pressurizing means)
25 steam passage
26 Pressure regulating valve (second valve)
31 decompression means
32 Pressure reduction pump (pressure reduction drive source)
33 Solenoid valve (first valve)
41 control means 44 heating means

Claims (2)

A pan that contains the food to be cooked,
A lid for sealing the inside of the pot,
Heating means for heating rice and water as the food to be cooked,
Decompression means for decompressing the object to be cooked to a state lower than atmospheric pressure,
Pressurizing means for pressurizing the object to be cooked to a state higher than atmospheric pressure,
Control means for controlling the heating means to heat the cooked food with rice,
The decompression means includes a decompression drive source, and a first valve that opens and closes a communication path between the inside of the pot and the decompression drive source,
The lid includes a steam passage for discharging steam generated inside the pot to the outside of the rice cooker,
The pressurizing means includes a second valve that opens and closes the steam passage,
The control means opens the path and continuously operates the decompression drive source over the entire duration of the hot water stroke to promote the water absorption of the rice to bring the cooked material into a decompressed state lower than atmospheric pressure, In the heating step following the hot-stroke step, the decompression means is controlled so as to maintain the decompressed state until the cooked object boils in a decompressed state, and the operation of the second valve so as to close the vapor passage. Control the
When the hot stock process is completed and the heating process is completed, the heating means heats the food to be cooked more strongly than the hot stock process, while controlling the operation of the first valve so as to close the path. Stop driving the decompression drive source,
When it is determined that the food to be cooked has boiled in a depressurized state in the heating step, the operation of the second valve is controlled so that the steam passage is temporarily opened and then closed to reduce the pressure of the food to be cooked. cooker being characterized in that from state once switched configuration to a high pressure state than the atmospheric pressure. The control means controls the operation of the first valve so as to continuously block the path even if it is determined that the food to be cooked has boiled in a depressurized state in the heating process, and drives the depressurization drive source. The rice cooker according to claim 1, wherein the rice cooker is configured to be stopped.