JP2020074942A - rice cooker - Google Patents

Abstract

To provide a rice cooker in which ebullition is generated by decompressing the inside of a pot, rice is gelatinized while being vertically agitated with boiling water, and unevenness of cooking in a vertical direction in the pot is suppressed.SOLUTION: A rice cooker includes: a pot 2 disposed in a rice cooker body; a lid part 4 for covering an opening 2a of the pot; an inner lid 3 disposed in the lid part, which includes an inner lid exhaust port 3a communicated with the inside of the pot; a lid part exhaust port 1a disposed in the lid part, which is communicated with ambient air; a heating part 7 for heating the pot; a temperature detection part 8 for detecting the temperature of the pot; a decompression part 5 for decompressing the inside of the pot; a gas-liquid separating part 11 for separating moisture from steam; a passage 6 in which the inner lid exhaust port 3a of the inner lid and the lid part exhaust port of the lid part are communicated with each other; and a control part 15 for controlling a heating amount given to the heating part, and executing rice cooking processes sequentially. The decompression part is disposed on a lid part exhaust port side in the passage, and the gas-liquid separating part is disposed on an inner lid exhaust port side in the passage. The control part causes the decompression part to be driven while the temperature detected by the temperature detection part is in a predetermined temperature range in a boiling-up process.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a rice cooker, and more particularly to a rice cooker that reduces pressure during cooking rice.

  Generally, a rice cooker in which a pan is provided in a main body so that the pan can be stored and a lid is provided so as to cover the pan is disclosed in, for example, Patent Document 1. As such a rice cooker, there is known a rice cooker provided with a decompression means for making the inside of the main body lower than the atmospheric pressure.

  FIG. 6 shows a conventional rice cooker 500 described in Patent Document 1. As shown in FIG. 6, a conventional rice cooker 500 includes a main body 50 formed of an upper frame 50a and an outer frame 50b that form an outer contour of the rice cooker 500, a bottom plate 51 that covers a bottom opening of the outer frame 50b, and an upper frame 50b. A substantially cylindrical pot accommodating portion 52 formed integrally with the inner peripheral portion of the upper surface of the frame 50a, an inner frame 53 provided so as to cover a lower surface opening of the pot accommodating portion 52, and an outer surface of the inner frame 53. Heating coils 54 provided on the lower side surface and the bottom surface facing the heating element, a bottomed cylindrical pan housing 56 made of a non-magnetic material for housing the pan 55, and a removable storage in the pan housing 56. It has a bottomed cylindrical pan 55 and a decompression means 58 provided for lowering the inside of the pan 55 to a normal atmospheric pressure with the lid 57 closed to the main body 50. The decompression means 58 is composed of a decompression pump as a decompression drive source provided in the rear part of the main body 50, and a tubular path 61 extending from this decompression pump through the main body 50 and the lid 57 to a hole provided in the inner lid 59. To be done.

  FIG. 7 shows a conventional rice cooker 600 described in Patent Document 2. As shown in FIG. 7, a conventional rice cooker 600 includes a rice cooker 70 for charging rice grains and cooking water, a lid 71 for sealing the opening of the rice cooker 70, and the inside and outside of the rice cooker 70 provided on the lid 71. An exhaust port communicating with the exhaust port, a depressurizing exhaust unit 72 connected to the exhaust port for depressurizing the inside of the rice cooker 70, a heating unit for heating the rice cooker 70, and a control unit for controlling the depressurizing exhaust unit 72 and the heating unit. There is. The control unit controls the decompression / exhaust means 72 so that the boiling point temperature of the cooking water becomes less than the gelatinization temperature of the rice grains at a timing before the temperature of the cooking water in the rice cooking pot 70 reaches the gelatinization temperature of the rice grains. To adjust the pressure in the rice cooker 70.

JP, 2008-200180, A JP, 2017-63957, A

  However, in the conventional rice cooker that performs decompression, the inner lid that covers the pan and the decompression pump that decompresses the pan do not directly communicate with each other to separate water, so that the water present in the pan When the water is boiled in a state where the pressure is reduced to the saturated vapor pressure, the water vapor may pass through the passage communicating with the pressure reducing pump and directly enter the pressure reducing pump. At that time, water vapor may condense in the decompression pump, degrading the performance of the decompression pump, and applying excessive load to the decompression pump, causing the decompression pump to malfunction. Therefore, there is a problem that the conditions under which the decompression pump can be driven are limited in a state where water is present in the pot, and a sufficient effect cannot be obtained.

That is, in the rice cooker described in Patent Document 1, it is limited to the hot water process at the time of reserved rice cooking and the heat retention process after completion of rice cooking, and the decompression pump cannot be driven in the rice cooking process, so that rice grains can be sufficiently supplied. Cannot stir.

  Further, in the rice cooker described in Patent Document 2, the boiling point temperature of the rice cooking water is lowered by depressurizing the inside of the rice cooker before the temperature of the rice cooking water in the rice cooker reaches the gelatinization temperature of rice grains. Since boiling of water starts immediately, if the decompression pump is stopped after detecting boiling, there is a problem that the substantial boiling time is shortened and a sufficient stirring effect cannot be obtained. On the contrary, if the decompression pump is not stopped after detecting boiling, steam directly flows into the decompression pump and the decompression performance deteriorates, and the decompression pump is overloaded and breaks down. There were challenges.

  The present invention has been made in view of the above problems of the prior art, in the passage that communicates the inner lid and the main body exhaust port, by depressurizing while separating water from steam generated in the pan, cook In the raising process, the rice can be gelatinized by stirring the rice up and down with convection of boiling water, so the difference in the water content of the rice in the vertical direction in the pan is reduced and the rice in the pan is cooked almost evenly. It aims at providing the rice cooker which can be.

In order to solve the problems of the above conventional technology, the rice cooker of the present invention is
With the rice cooker body,
A pot placed inside the rice cooker body,
A lid that covers the opening of the pot,
An inner lid having an inner lid exhaust port which is arranged on the lid portion and communicates with the inside of the pot,
A lid exhaust port that is arranged on the lid and communicates with the outside air;
A heating unit for heating the pot,
A temperature detection unit for detecting the temperature of the pot,
A decompression unit for decompressing the inside of the pan,
A gas-liquid separator that separates water from water vapor,
A passage through which the inner lid exhaust port of the inner lid and the lid exhaust port of the lid section communicate with each other;
A water absorption step by controlling the amount of heat applied to the heating section, a cooking step, a boiling step, and a control section that sequentially executes the rice cooking step of the mudling step,
Equipped with
In the passage, the pressure reducing portion is arranged on the lid portion exhaust port side, and in the passage, the gas-liquid separating portion is arranged on the inner lid exhaust port side,
The control unit is configured to drive the decompression unit while the temperature detected by the temperature detection unit is within a predetermined temperature range in the cooking step.

Thereby, the control unit is configured to drive the decompression unit while the temperature detected by the temperature detection unit is within the predetermined temperature range in the cooking process, so that a predetermined amount of water in the pan is held. , The water can move freely in the pot.
This allows the rice to be gelatinized while being stirred up and down by convection of boiling water in the cooking process, reducing the difference in the water content of the rice in the vertical direction in the pan, and making the rice in the pan almost A rice cooker that can cook uniformly can be provided. In addition, the gas-liquid separation unit can separate the water from the steam generated in the pan and prevent the water from flowing into the decompression unit, so that the performance of the decompression unit and the failure thereof can be prevented.

  According to the rice cooker of the present invention, boiling can be generated under a pressure environment lower than atmospheric pressure, and the rice can be gelatinized while being stirred up and down by convection of boiling water. The difference in the water content of the rice can be reduced, and the rice in the pan can be cooked almost uniformly.

The schematic diagram which shows the state at the time of decompression of the rice cooker in Embodiment 1 of this invention. The schematic diagram which shows the state at the time of normal of the rice cooker in Embodiment 1 of this invention. Flow diagram showing the rice cooking process of the rice cooker in Embodiment 1 of the present invention The characteristic view which shows the detection temperature of the temperature sensor of the rice cooker in Embodiment 1 of this invention. The characteristic view which shows the pressure in the pan of the rice cooker and the boiling point of water in Embodiment 1 of this invention. Schematic diagram showing a conventional rice cooker Sectional view showing a conventional rice cooker

The first invention is
With the rice cooker body,
A pot placed inside the rice cooker body,
A lid that covers the opening of the pot,
An inner lid having an inner lid exhaust port which is arranged on the lid portion and communicates with the inside of the pot,
A lid exhaust port that is arranged on the lid and communicates with the outside air;
A heating unit for heating the pot,
A temperature detection unit for detecting the temperature of the pot,
A decompression unit for decompressing the inside of the pan,
A gas-liquid separator that separates water from water vapor,
A passage through which the inner lid exhaust port of the inner lid and the lid exhaust port of the lid section communicate with each other;
A water absorption step by controlling the amount of heat applied to the heating section, a cooking step, a boiling step, and a control section that sequentially executes the rice cooking step of the mudling step,
Equipped with
In the passage, the pressure reducing portion is arranged on the lid portion exhaust port side, and in the passage, the gas-liquid separating portion is arranged on the inner lid exhaust port side,
The control unit is configured to drive the decompression unit while the temperature detected by the temperature detection unit is within a predetermined temperature range in the cooking step.

Thereby, the control unit is configured to drive the decompression unit while the temperature detected by the temperature detection unit is within the predetermined temperature range in the cooking process, so that a predetermined amount of water in the pan is held. , The water can move freely in the pot.
This allows the rice to be gelatinized while being stirred up and down by convection of boiling water in the cooking process, reducing the difference in the water content of the rice in the vertical direction in the pan, and making the rice in the pan almost A rice cooker that can cook uniformly can be provided.

  A second aspect of the invention is the rice cooker according to the first aspect of the invention, in which the predetermined temperature range detected by the temperature detection unit is 60 ° C to 90 ° C. As a result, the decompression unit is driven while the detected temperature detected by the temperature detection unit is within the predetermined temperature range of 60 ° C to 90 ° C, and the water in the pan is kept in a state where the water in the pan is kept in a predetermined amount. You will be able to move freely. As a result, in the cooking process, the rice can be gelatinized while being stirred up and down by convection of boiling water, reducing the difference in the water content of the rice in the vertical direction in the pan, and reducing the rice in the pan A rice cooker that can cook uniformly can be provided.

  A third aspect of the invention is the rice cooker according to the first or second aspect of the invention, in which the pressure reducing portion is driven at a flow rate of 3 L / min to 30 L / min. This maintains the balance between the generation rate of water vapor generated by the reduced pressure boiling and the reduced pressure rate, and the reduced pressure boiling can be continued for a predetermined time.

Hereinafter, preferred embodiments of the rice cooker of the present invention will be described in detail with reference to the drawings. In the following description, the same or corresponding parts will be denoted by the same reference symbols, without redundant description. The present invention is not limited to this embodiment.

(Embodiment 1)
The first embodiment of the rice cooker of the present invention will be described below with reference to FIGS. 1 to 5. FIG. 1 is a schematic diagram showing a state of the rice cooker according to the first embodiment of the present invention when decompressing. FIG. 2 is a schematic diagram showing a normal state of the rice cooker according to Embodiment 1 of the present invention. FIG. 3: is a flowchart which shows the rice cooking process of the rice cooker in Embodiment 1 of this invention. FIG. 4 is a characteristic diagram showing detected temperatures of the temperature sensor of the rice cooker according to Embodiment 1 of the present invention. FIG. 5: is a characteristic view which shows the pressure in the pan of the rice cooker and the boiling point of water in Embodiment 1 of this invention.

  As shown in FIG. 1, a rice cooker 100 according to the present embodiment includes a rice cooker main body 1, a pan 2 arranged in the rice cooker main body 1, a lid 4 for covering an opening 2a of the pan 2, and a lid. An inner lid 3 that has an inner lid exhaust port 3a that is arranged in the portion 4 and communicates with the inside of the pan 2, a lid exhaust port 1a that is arranged in the lid part 4 and that communicates with the outside air, and a heating unit 7 that heats the pan 2. A decompression pump 5, which is a decompression unit 5 that decompresses the inside of the pan 2, a gas-liquid separation unit 11 that separates water from water vapor, an inner lid exhaust port 3a of the inner lid 3, and a lid exhaust port 1a of the lid unit 4. It is provided with a passage 6 that communicates with a temperature detector 8 that detects the temperature of the pot 2.

  The rice cooker 100 further includes a control unit 15 that controls the amount of heat applied to the heating unit 7 and sequentially executes the water absorption process, the cooking process, the boiling process, and the rice cooking process of the Murashi process. .. The control unit 15 controls the decompression pump 5, which is the decompression unit 5, according to the rice cooking process.

  The lid portion 4 arranged on the upper portion of the rice cooker body 1 has an inner lid 3, a decompression pump 5, a lid portion exhaust port 1a, a passage 6, and a gas-liquid separating portion 11. The lid exhaust port 1 a communicates with the outside air, which is the outside of the lid 4.

  A decompression pump 5, which is a decompression unit 5, is arranged in the passage 6 on the lid exhaust port 1a side, and a gas-liquid separation unit 11 is arranged in the passage 6 on the inner lid exhaust port 3a side.

  Here, the heating part 7 should just be comprised so that the pan 2 arrange | positioned at the pan storage part of the rice cooker main body 1 may be heated. For example, it may be configured by a heating coil 7 that induction-heats the pot 2, or may be configured by an electric resistance type heater that contacts the pot 2 and directly heats the pot 2. Moreover, the temperature detection unit 8 may be configured to detect the temperature of the pan 2 arranged in the pan storage portion of the rice cooker body 1. For example, the temperature of the pan 2 may be configured by a contact-type temperature sensor that contacts the pan 2 such as a thermistor, or an infrared sensor may measure the temperature of the pan 2 without contacting the pan 2. The temperature sensor 8 may be of a contact type. In the present embodiment, a configuration will be described in which the heating unit 7 is composed of the induction heating heating coil 7 and the temperature detection unit 8 is composed of the contact temperature sensor 8.

The heating coil 7 and the decompression pump 5 are controlled by the controller 15 according to the temperature detected by the temperature sensor 8 in contact with the bottom of the pan. A decompression control valve 9 is arranged on the suction side of the decompression pump 5, and a control valve 10 is arranged between the inner lid 3 and the steam exhaust port 1b. The pressure reducing control valve 9 and the control valve 10 are driven and controlled by the control unit 15 to open and close. As shown in FIG. 1, when decompressing the inside of the pan 2 with the decompression pump 5, the decompression control valve 9 is opened and the control valve 10 is closed, so that the inner lid 3 and the steam exhaust port are closed. The passage communicating with 1b is closed, and the gas A can flow only in the passage 6 communicating with the inner lid 3 and the lid exhaust port 1a. On the contrary, as shown in FIG. 2, when the pressure in the pan 2 is not reduced, the pressure reducing control valve 9 is closed and the control valve 10 is opened, so that the inner lid 3 and the lid exhaust port are opened. It is possible to block the passage 6 that communicates with 1a and allow the gas B to flow only in the passage that communicates the inner lid 3 and the vapor exhaust port 1b. That is, by controlling the open / close state of the pressure reducing control valve 9 and the control valve 10 by the control unit 15, two passages that connect the inner lid 3 and the lid exhaust port 1a or the vapor exhaust port 1b are connected to each other inside the pan 2. It becomes possible to select according to.

  As shown in FIG. 1, in the passage 6 that connects the inner lid 3 and the lid portion exhaust port 1 a, between the inner lid exhaust port 3 a of the inner lid 3 and the decompression control valve 9 is a gas-liquid separation unit 11. A cooling unit 11 is provided. The cooling unit 11 is housed in the lid 4 so as to cool a part of the passage 6. The cooling unit 11 has a fan 12 that forcibly blows air to the passage walls forming the passage 6. The fan 12 is drive-controlled by the controller 15.

  When the fan 12 arranged above the cooling unit 11 is driven, the cooling air is forcibly blown from the fan 12 to the cooling unit 11 to cool the cooling unit 11. The lower surface of the cooling unit 11 is connected to the passage 6 with a low thermal resistance. For example, the cooling unit 11 and the lid of the rice cooker body 1 may be formed of metal and welded to each other, or may be formed by adhering with an adhesive having high thermal conductivity. Alternatively, the lower surface of the cooling unit 11 may form a part of the passage 6. In the present embodiment, the cooling part 11 is made of aluminum and the passage 6 is partially formed by the lower surface of the cooling part 11. The flow rate of the cooling air blown from the fan 12 to the cooling unit 11 can be controlled according to the number of blades, the shape, and the number of rotations of the fan 12, and the effect of cooling the cooling unit 11 can be improved by increasing the flow rate. Is. Since the air flowing into the fan 12 is taken in from the outside of the lid portion 4, the pot 2 is heated by the heating portion 7 during rice cooking, and the passage 6 that connects the inner lid 3 and the lid portion exhaust port 1a. There is a large temperature difference with the steam flowing through. Therefore, even the air blown to the cooling unit 11 by the fan 12 can sufficiently cool the steam passing through the passage 6.

The operation and action of the rice cooker 100 configured as above will be described below.
When the user puts a predetermined amount of rice and water into the pan 2 and starts the rice cooking process, a current flows through the heating coil 7 and the pan 2 itself generates heat due to induction heating. The heat of the pot 2 heats the rice and water in the pot 2. As shown in FIG. 3, the rice cooking process performed by the rice cooker 100 of the present embodiment includes four processes in the order of time: a water absorbing process, a cooking process, a boiling maintaining process, and a muting process.

  The control unit 15 controls the amount of heat applied to the heating coil 7 and sequentially executes the water absorption process, the cooking process, the boiling maintaining process, and the rice cooking process of the muddling process. The water absorption step is a step of immersing rice in water having a temperature lower than the gelatinization temperature and allowing the rice to absorb water in advance so that the central portion of the rice is sufficiently gelatinized in the subsequent steps. The cooking step is a step of heating the bottom surface of the pot 2 with the heating coil 7 to raise the temperature of water to the boiling point of water. The boiling maintaining step is a step of heating the bottom surface of the pot 2 with the heating coil 7 at appropriate times to maintain the boiling state of the water in the pot 2 and at the same time heating until the water in the pot 2 is exhausted. The Murashi process is a process of keeping the rice cooked in the cooking process at a temperature at which the rice is not dried or burnt and the pan 2 as a whole, that is, the rice is kept hot, so that the rice is gelatinized to the core. .. The rice cooker 100 detects the temperature of the pan 2 with a temperature sensor 8 arranged at the lower center of the pan 2.

As shown in FIG. 4, the detection temperature Ta detected by the temperature sensor 8 during the rice cooking process is different in the above four processes, and the detection temperature T0 is the initial temperature at the start of rice cooking (for example, room temperature 20 ° C.), the detection. The temperature T1 is an appropriate temperature (for example, 40 ° C. to 60 ° C.) for promoting water absorption into the rice without causing gelatinization of rice in the water absorption step, and the detection temperature T2 is water boiling at atmospheric pressure. Temperature (normally 100 ° C.), and the detection temperature T3 indicates a temperature set to detect that the water in the pot 2 is exhausted. When the water absorption process is completed and the process moves to the cooking process, the temperature in the pan 2 gradually rises from the detection temperature T2 to the detection temperature T3. In the cooking process, the temperature at which the gelatinization of rice rapidly progresses, so the rice absorbs the water in the pot 2 and gelatinizes. When the pot 2 is heated, the rice in contact with the pot 2 transfers heat from the pot 2 and heat from the water existing around the rice. On the other hand, with respect to rice that is not in contact with the pot 2, heat is transferred only from the water around the rice, so the heat transfer state when the pot 2 is heated differs between rice that has contact with the pot 2 and rice that does not have contact with the pot 2. .. As the gelatinization of rice progresses, it absorbs water and grows in size, increasing the surface area of the rice. In the case of rice that has contact with the pot 2, as the surface area of the rice increases, the area in contact with the pot 2 increases. During the rice cooking process, the heating of the pan 2 is controlled by the temperature detected by the temperature sensor 8 arranged in the lower center of the pan 2, but strictly speaking, the temperature of the pan 2 itself is higher than the water temperature in the pan 2. There is a moment when it gets higher. That is, there is a slight time difference between the heat generation of the pot 2 and the heat conduction to the water in the pot 2, and the temperature of the water present in the pot 2 does not become higher than the temperature of the pot 2. In addition, there is a slight difference in water temperature between the top and bottom of the pot 2, and the temperature difference causes convection in the pot 2.

  In addition, when the gelatinization of rice progresses in the cooking process, the starch in the rice flows out into the water in the pan 2 to become highly viscous water (hereinafter referred to as "onba"). As the water absorption of rice progresses and the amount of water in the pan 2 decreases, the viscosity of the rice cake becomes higher. The onion is present so as to cover the rice, and the rice having a contact point with the pot 2 easily adheres to the pot 2. Therefore, even if convection occurs in the pot 2, the rice is less likely to be stirred by the convection.

  In the present embodiment, during the cooking process, the control unit 15 in the rice cooker 100 closes the control valve 10 and the decompression control valve 9 to open the decompression pump 5 and the fan 12 for a predetermined time. To drive. When the fan 12 is driven, the fan 12 is forcedly blown to the cooling unit 11, and the cooling unit 11 is cooled. Further, when the decompression pump 5 is driven, the air existing in the pan 2 is discharged to the outside of the lid portion 4 through the passage 6 that connects the inner lid exhaust port 3a of the inner lid 3 and the lid exhaust port 1a. Then, the pressure in the pot 2 is reduced.

  As shown in FIG. 5, when the pressure in the pan 2 decreases from atmospheric pressure, the boiling point of water in the pan 2 also decreases from 100 ° C. That is, in the cooking process, when the temperature inside the pan 2 rises and the pressure inside the pan 2 is reduced by driving the decompression pump 5 by the control unit 15 for a predetermined time, the water inside the pan 2 is reduced. Since the boiling point is lowered, the water starts to boil between the temperatures T2 and T3 detected by the temperature sensor 8 arranged at the lower center of the pot 2. When the water starts to boil, water vapor is generated in the pot 2 and starts to flow out from the inner lid exhaust port 3 a of the inner lid 3. The water vapor flowing out from the inner lid exhaust port 3a of the inner lid 3 contacts the cooling unit 11 cooled by the fan 12 while flowing through the passage 6 toward the pressure reducing pump 5 side. The water vapor is cooled in the cooling unit 11 and its temperature drops, and the water contained in the water vapor condenses in the passage 6 to remove the water from the water vapor. The remaining air passes through the decompression pump 5 and flows out of the lid 4 from the lid exhaust port 1a. In other words, even if the water in the pot 2 is boiled in a state where the pot 2 is depressurized, the air passing through the decompression pump 5 becomes air with little water content, so that the decompression performance of the decompression pump 5 is not deteriorated. The reduced pressure boiling in the pan 2 can be continued.

  In the cooking process, if the temperature of the water existing in the pan 2 exceeds 90 ° C, the amount of water that can be moved freely in the pan 2 will decrease because the water added before cooking rice will be absorbed by the gelatinization of the rice. Since the rice absorbs water, the effect of stirring the rice by convection is small. Also, in the water absorption process, gelatinization of rice is difficult to proceed, and the amount of water that can freely move in the pan 2 is large. However, even if the inside of the pan 2 is depressurized and boiled in the water absorption process, Although rice is agitated, gelatinization does not proceed because the amount of water in the pan 2 decreases, and proper rice cannot be cooked.

  That is, in the cooking process, when the water in the pan 2 is present to some extent, the decompression pump 5, which is the decompression unit 5, is driven to decompress the pan in the pan 2 to stir the rice in the pan 2 by convection. By gelatinizing while making it possible, the rice in the pan 2 can be gelatinized with proper stirring, so that the difference in water content between the upper and lower rice in the pan 2 is small, and uniform cooking with little unevenness in cooking is achieved. can do.

  In the present embodiment, the temperature sensor 8 arranged at the lower center of the pot 2 is boiling the inside of the pot 2 under reduced pressure in the range of 60 ° C to 90 ° C.

  When the time for boiling under reduced pressure is short, the effect of stirring the rice in the pan 2 is small and the effect of reducing uneven cooking is small. On the other hand, if the boiling time under reduced pressure is too long, the stick in the pot 2 is pulled toward the reduced pressure side (the upper side of the pot 2 in the present embodiment) and cooks in a biased state, which makes cooking the rice unfavorable. In other words, the time for boiling under reduced pressure depends on the rice cooking conditions such as the amount of rice and water, the decompression performance of the decompression pump 5, and the position, and it is necessary to set an appropriate time.

  In the boiling under reduced pressure in the cooking process, when the amount of water that can move freely in the pan 2 is small, the effect of stirring rice by convection becomes small, so the temperature of the water in the pan 2 is between 60 ° C and 90 ° C. It is preferable to boil under reduced pressure.

  Further, when the reduced pressure boiling starts in the pot 2, steam is generated in the pot 2 and acts in the direction of increasing the pressure in the pot 2. Therefore, in order to continue the reduced pressure boiling for a predetermined time, the steam generated by the reduced pressure boiling is required. It is necessary to select the flow rate of the decompression pump 5 in consideration of the balance between the generation rate and the decompression rate. Although it depends on the size of the pan 2 and the heating conditions in the cooking process, in a general domestic rice cooker, the pressure reducing pump 5 preferably has a flow rate of 3 L / min to 30 L / min. In the present embodiment, the inside of the pan 2 is decompressed from the upper part of the pan 2, and the decompression pump 5 has a decompression flow rate of 15 L / min and a pressure of -70 kPa. By using a plurality of decompression pumps 5, the performance of the decompression pumps 5 can be adjusted. For example, if two identical decompression pumps 5 are connected in series, the pressure that can be decompressed will almost double, and By connecting two of the same decompression pumps 5 in parallel, the decompression flow rate can be approximately doubled, and they can be used in combination according to the required decompression performance.

As described above, the rice cooker 100 according to the present embodiment includes the rice cooker main body 1, the pan 2 arranged in the rice cooker main body 1, the lid 4 that covers the opening 2 a of the pan 2, and the lid 4. , An inner lid 3 having an inner lid exhaust port 3a that communicates with the inside of the pan 2, a lid exhaust port 1a that is disposed on the lid part 4 and communicates with the outside air, a heating unit 7 that heats the pan 2, and a pan 2 Temperature detection unit 8 for detecting the temperature of the inner pot, a decompression unit 5 for decompressing the inside of the pan 2, a gas-liquid separation unit 11 for separating water from water vapor, an inner lid exhaust port 3a of the inner lid 3, and a lid of the lid unit 4. A passage 6 that communicates with the partial exhaust port 1a, a control unit 15 that sequentially controls the amount of heat applied to the heating unit 7, the water absorption process, the cooking process, the boiling process, and the steaming rice cooking process. Equipped with
The decompression unit 5 is arranged in the passage 6 on the lid exhaust port 1a side, and the gas-liquid separating unit 11 is arranged in the passage 6 on the inner lid exhaust port 3a side. The pressure reducing unit 5 is configured to be driven while the detected temperature detected by the temperature detecting unit 8 is within a predetermined temperature range.

  Thus, the control unit 15 drives the decompression unit 5 while the detected temperature detected by the temperature detection unit 8 is within the predetermined temperature range in the cooking process, so that the water in the pan 2 is kept in a predetermined amount. In this state, water can move freely inside the pan 2.

  As a result, in the cooking process, the rice can be gelatinized while being stirred up and down by convection of boiling water, so that the difference in the water content of the rice in the vertical direction in the pan 2 is reduced and the rice in the pan 2 is reduced. It is possible to provide a rice cooker 100 that can cook rice substantially uniformly.

Further, the predetermined temperature range detected by the temperature detection unit 8 in the rice cooker 100 of the present embodiment is set to 60 ° C to 90 ° C. As a result, the decompression unit 5 is driven while the detected temperature detected by the temperature detection unit 8 is within the predetermined temperature range of 60 ° C. to 90 ° C., and the water in the pan 2 is held in a predetermined amount and the pan 2 is held. Water will be able to move freely inside. As a result, in the cooking process, it is possible to gelatinize the rice while stirring the rice up and down by convection of boiling water,
The difference in the water content of the rice in the vertical direction in the pan 2 can be reduced, and the rice in the pan 2 can be cooked substantially uniformly.

  Further, the depressurizing unit in the rice cooker 100 of the present embodiment is driven at a flow rate of 3 L / min to 30 L / min. This maintains the balance between the generation rate of water vapor generated by the reduced pressure boiling and the reduced pressure rate, and the reduced pressure boiling can be continued for a predetermined time.

  According to the rice cooker of the present invention, the inside of the pot is depressurized, the water present in the pot is caused to boil under a pressure environment lower than atmospheric pressure, and the rice is gelatinized while stirring the rice up and down with boiling water. Since the unevenness of cooking rice in the vertical direction in the pan can be reduced, it can be suitably applied to the fields and uses of domestic and commercial rice cookers.

1 Rice Cooker Main Body 1a Lid Exhaust Port 1b Steam Exhaust Port 2 Pan 2a Opening 3 Inner Lid 3a Inner Lid Exhaust Port 4 Lid 5 Decompression Unit (Decompression Pump)
6 passages 7 heating part (heating coil)
8 Temperature detector (temperature sensor)
9 Pressure reducing control valve 10 Control valve 11 Gas-liquid separation unit (cooling unit)
12 fan 15 control unit 100 rice cooker

Claims (3)

With the rice cooker body,
A pot placed inside the rice cooker body,
A lid that covers the opening of the pot,
An inner lid having an inner lid exhaust port which is arranged on the lid portion and communicates with the inside of the pot,
A lid exhaust port that is arranged on the lid and communicates with the outside air;
A heating unit for heating the pot,
A temperature detector for detecting the temperature of the pot,
A decompression unit for decompressing the inside of the pan,
A gas-liquid separator that separates water from water vapor,
A passage through which the inner lid exhaust port of the inner lid and the lid exhaust port of the lid section communicate with each other;
A water absorption step by controlling the amount of heat applied to the heating section, a cooking step, a boiling step, and a control section that sequentially executes the rice cooking step of the mudling step,
Equipped with
In the passage, the pressure reducing portion is arranged on the lid portion exhaust port side, and in the passage, the gas-liquid separating portion is arranged on the inner lid exhaust port side,
The rice cooker configured to drive the decompression unit while the temperature detected by the temperature detection unit is within a predetermined temperature range in the cooking step. The rice cooker according to claim 1, wherein the predetermined temperature range detected by the temperature detection unit is 60 ° C to 90 ° C. The rice cooker according to claim 1 or 2, wherein the decompression unit is driven at a flow rate of 3 L / min to 30 L / min.