JP4602938B2 - Pressure cooker - Google Patents

Description

  The present invention relates to a pressure rice cooker that can bring out the glutinous feeling of rice.

  Conventionally, for example, as shown in Patent Document 1 and Patent Document 2, pressure adjusting means for pressurizing or depressurizing the pressure in the inner pot during the rice cooking process, and pressure releasing means for releasing the pressure in the inner pot are provided. Pressure cookers are known. In the pressure rice cooker of patent document 1, the pressure in the inner pot in the unevenness process was set to atmospheric pressure, and was not pressurized here. In the rice cooker of patent document 2, in order to prevent that the inside of an inner pot becomes a negative pressure by the uneven process, it is controlled above atmospheric pressure.

Moreover, as shown in patent document 3 and patent document 4, the rice cooker which adjusts pressure with one pressure regulation ball | bowl is well-known. In the pressure rice cooker of patent document 3, a pressurization mode is cancelled | released by moving a pressure regulation ball | bowl after completion of natural pressure reduction in the unevenness process. In the rice cooker of Patent Document 4, the pressure is reduced to near atmospheric pressure in the unevenness process, but the pressure is not increased thereafter.
JP 2004-57556 A JP 2006-273 A JP 2000-37291 A JP 2005-334624 A

  Thus, in the conventional pressure rice cooker, if it continues to pressurize until the completion of rice cooking, excess moisture cannot be completely discharged, and the deliciousness of the rice is impaired. On the other hand, if the pressure is reduced in the uneven process, there is a problem that the feeling of stickiness is lost.

  Then, this invention makes it a subject to provide the pressure rice cooker which can draw out the glutinous feeling of rice while skipping excess moisture.

In order to solve the above problems, the first invention provides:
An inner pot that contains rice cooking ingredients and is sealed with an inner lid;
Heating means for heating the pan;
Pressure adjusting means for adjusting the pressure in the inner pot;
The heating means is controlled to perform preheating, boiling, boiling maintenance, and uneven rice cooking processes, and the pressure adjusting means is operated to increase or decrease the pressure in the inner pot in the rice cooking process. In a pressure cooker equipped with a control means,
The said control means operates the said pressure adjustment means after completion | finish of a boiling maintenance process, depressurizes the pressure in the said inner pot, and pressurizes it again at the time of a nonuniformity process.

  In the first aspect of the invention, the pressure value to be reduced after the boiling maintaining step is preferably equal to or lower than the pressure value controlled in the unevenness step, and is preferably substantially atmospheric pressure. By setting the pressure to approximately atmospheric pressure, excess water can be sufficiently removed.

  Further, it is preferable that the pressure value to be pressurized again during the unevenness process is low when the pressure value controlled in the boiling maintenance process is low and is high when the pressure value controlled in the boiling maintenance process is high. Thereby, the feeling of stickiness according to the pressure of a boiling maintenance process can be given.

In addition, the second invention
An inner pot that contains rice cooking ingredients and is sealed with an inner lid;
Heating means for heating the pan;
Pressure adjusting means for adjusting the pressure in the inner pot;
The heating means is controlled to perform preheating, boiling, boiling maintenance, and uneven rice cooking processes, and the pressure adjusting means is operated to increase or decrease the pressure in the inner pot in the rice cooking process. In a pressure cooker equipped with a control means,
The control means naturally depressurizes the pressure in the inner pot after the boiling maintenance step, and pressurizes again during the unevenness step,
The pressure value to be pressurized again during the unevenness process is low when the pressure value controlled in the boiling maintenance process is low, and is high when the pressure value controlled in the boiling maintenance process is high.

  In the first invention and the second invention, it is preferable that a pressure value to be repressed during the unevenness step is equal to or less than a pressure value controlled in the boiling maintenance step. Thereby, the feeling of stickiness according to the pressure of a boiling maintenance process can be given.

  Moreover, it is preferable to change the time after the said boiling maintenance process is complete | finished until it pressurizes again at the time of the said unevenness process according to a rice cooking menu.

  Furthermore, it is preferable to change the time which pressurizes again at the said unevenness process according to a rice cooking menu.

  According to the present invention, since the pressure in the inner pot is reduced after the boiling maintenance step is completed, excess water is blown off, and further pressurization is performed during the stripping step, so that the feeling of stickiness of rice can be further extracted.

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

  FIG. 1 shows a pressure cooker 1 according to the present invention. The pressure cooker 1 includes an inner pot 2, a main body 3 and a lid 4.

  The inner pot 2 is formed by coating or joining a ferromagnetic material on the outer surface of a pot base material made of aluminum or the like having high thermal conductivity.

  The main body 3 includes a protective frame 5 made of a non-conductive material that accommodates the inner pot 2 inside a body 3a having a bottomed cylindrical shape. Between the body 3a and the protective frame 5, an induction heating coil 6 as a heating means, a temperature sensor 7 for an inner pot, and a microcomputer 8 as a control means are arranged.

  The induction heating coil 6 is disposed on the lower surface of the protective frame 5 and electromagnetically heats the inner pot 2 when a high frequency current is applied.

  The inner pot temperature sensor 7 is disposed at the bottom of the protective frame 5, detects the temperature of the inner pot 2, and outputs the temperature of the inner pot 2 to the microcomputer 8.

  The lid 4 closes the opening portions of the inner pot 2 and the main body 3 so as to be openable, and includes a lid upper plate 4a and a lid lower plate 4b. On the inner pot 2 side of the lid 4, a heat radiating plate 9, a lid heater 10 and an inner lid 11 are disposed. In addition, a lid temperature sensor 12, a pressure sensor 13, a relief valve 14, and a pressure regulator 15 are disposed inside the lid 4.

  The lid temperature sensor 12 detects the temperature in the inner pot 2 and outputs the detected temperature to the microcomputer 8.

  The pressure sensor 13 is arranged so that the detection part faces the inside of the inner pot 2, detects the pressure in the inner pot 2, and outputs a voltage value corresponding to the detected pressure to the microcomputer 8. To do.

The relief valve 14 is disposed from above the opening 16 communicating with the inner pot 2 and has a well-known configuration including a pressure adjusting ball 16 that closes the opening 16 by its own weight. Inside the lid body 4, a steam discharge path 19 is formed from the opening 16 to the steam port 18 of the lid body 4. At the time of cooking, the pressure adjusting ball 17 closes the opening 16 with its own weight, while the inner pressure of the inner pot 2 exceeds 0.52 kg / cm ² (1.5 atm), for example. It floats by the steam in the pot 2 and discharges the steam in the inner pot 2 to the outside. Thereby, when the inside of the inner pot 2 becomes an abnormally high pressure, the internal pressure is released.

  As shown in FIG. 2, the pressure adjusting device 15 includes a closing valve portion 20, a closing valve pressing portion 21, an arm portion 22 (pressing portion moving means), and a stepping motor 23.

  The blocking valve portion 20 includes a blocking valve housing portion 20a and a blocking valve 20b. The shut-off valve accommodating portion 20a is attached to the inner lid 11 and has an exhaust port 24 formed therein. The blocking valve 20b is disposed so as to be movable in the vertical direction in the blocking valve housing portion 20a.

  The blocking valve pressing portion 21 includes a case member 21a and a pressing portion 21b. The case member 21a is attached and fixed to the upper surface of the inner lid 11 by engaging with the closing valve accommodating portion 20a. The lower portion of the pressing portion 21b is disposed inside the case member 21a, and the upper portion protrudes upward from the insertion hole 25 of the case member 21a so as to be movable in the vertical direction. A spring 26 is provided between the lower surface of the pressing portion 21b and the upper surface of the blocking valve 20b. The spring 26 presses the closing valve 20b downward to close the exhaust port 24. The periphery of the closing valve pressing portion 21 is covered with an elastic cap 27 made of elastic rubber or the like. The lower portion of the elastic cap 27 is sandwiched between the heat sink 9 and the inner lid 11. A plurality of flow ports 28 are formed in the shoulder portion of the elastic cap 27.

  The arm portion 22 (pressing portion moving means) is attached so as to be rotatable about a shaft 30 fixed to the motor stay 29. An arc-shaped rack 31 is provided at the tip of the arm portion 22. The intermediate portion of the arm portion 22 is in contact with or attached to the top of the elastic cap 27.

  The stepping motor 23 is driven to rotate in both directions (forward or reverse direction) as indicated by an arrow P in FIG. The stepping motor 23 is fixed to a motor stay 29 attached to the lid lower plate 4b, and the output shaft of the stepping motor 23 meshes with the rack 31 of the arm portion 22 via a pinion gear 32. ing. When the stepping motor 23 is rotationally driven in the forward direction or the reverse direction, the arm portion 22 is rotationally driven in a clockwise direction or a counterclockwise direction indicated by an arrow Q in FIG. Thereby, the said press part 21b moves to the obstruction | occlusion direction or an open | release direction along the perpendicular direction shown by the arrow R in FIG. A micro switch 33 for setting the zero point of the stepping motor 23 is attached to the motor stay 29. That is, the stepping motor 23 reverses and the arm portion 22 rotates counterclockwise, and the pressing portion 21b is positioned at an open position (upper end in the vertical direction) described later, and at the same time, the arm portion 22 is moved to the micro switch 33. The point that contacts and turns on is defined as the zero point. Further, from this zero point, the stepping motor 23 is rotated forward by a predetermined pulse, the arm portion 22 is rotated in the clockwise direction, and the pressing portion 21b is located at a closing position (lower end in the vertical direction) described later. It is called MAX point.

  In the pressure adjusting device 15, when the internal pressure of the inner pot 2 rises during rice cooking, the closing valve 20 b is pushed up by the steam in the inner pot 2 against the elastic force of the spring 26, and thereby the steam in the inner pot 2. Is discharged to the outside through the steam discharge path 19.

  Next, operation | movement by the microcomputer 8 of the said pressure rice cooker 1 is demonstrated.

  First, as a rice cooking material, the user accommodates rice in the desired number of cups and the amount of water required to cook the rice in the inner pot 2, and after setting the inner pot 2 in the main body 3, Press the rice cooker switch 31.

  Then, the microcomputer 8 starts the rice cooking flow as shown in the flowchart of FIG. In step S10, energization of the induction heating coil 6 is started, and preheating is performed by adjusting the temperature so that the temperature of the inner pot 2 is about 50 ° C. (preheating step).

  Then, when the predetermined time has elapsed, in step S11, the microcomputer 8 energizes the induction heating coil 6 with 100% (full power) and executes the middle papper process (boiling process). In Step S12, if it is judged by the inner pot temperature sensor 7 that the temperature in the inner pot 2 has reached 100 ° C., the amount of current supplied to the induction heating coil 6 is controlled to execute the power control process (boiling maintenance process). . In step S13, the induction heating coil 6 is again energized with 60 to 70% power, and the temperature in the inner pot 2 is raised to 100 ° C. or higher to perform the cooking process (boiling maintenance process).

  When the microcomputer 8 detects dry-up by a well-known method, the microcomputer 8 starts energizing the lid heater 10 disposed on the lid body 4 in step S14, and performs steaming and dew condensation (unevening process) for a predetermined time. And the microcomputer 8 transfers to a heat retention process similarly to a well-known pressure rice cooker in step S15 (heat retention process).

  The microcomputer 8 performs pressure regulation control using the pressure regulating device 15 during the middle papper process, the power control process, the cooking process, and the unevenness process. That is, the AD value corresponding to the voltage value output from the pressure sensor 13 is maintained between the pressure upper limit value (AD value) and the pressure lower limit value (AD value) stored in advance in the microcomputer 8 for each process. In addition, the stepping motor 23 is controlled to increase or decrease the pressing force of the blocking valve 20b by the spring 26.

  Next, the unevenness process before the heat retention process after the cooking process will be described in more detail.

  In FIG. 4, when the cooking process in step S13 is completed, the unevenness 1 (steps S14.1 to S14.2), the twice cooking (steps S14.3 to S14.5), and the unevenness 2 (step S14.6). To S14.7) are sequentially executed.

  In the unevenness 1 process, the pressure regulator 15 is operated in step S14.1 to perform pressure reduction control. In this depressurization control, the inner pot is depressurized to a pressure lower than the pressure repressed in the twice-cooking step described later, preferably to approximately atmospheric pressure (1.0 atm). Thereby, the steam in the inner pot after cooking is discharged | emitted outside from the exhaust port 24 of the pressure regulator 15 through the vapor | steam discharge path 19, and an excess water | moisture content is blown away. In step S14.2, it is determined whether a predetermined transition time has elapsed. If the transition time has not elapsed, the decompression control is continued, and if it has elapsed, the process proceeds to the twice cooking step (steps S14.3 to S14.5).

  In the twice-cooking process, the heater is controlled by energizing the induction heating coil 6 and the lid heater 10 in step S14.3, and the pressure control is performed by operating the pressure regulator 15 in step S14.4. Thereby, since the inside of an inner pot is pressurized again after a boiling maintenance process, a sticky feeling can be pulled out further. In step S14.5, it is determined whether a predetermined transition time has elapsed. If the transition time has not elapsed, the heater control is continued, and if it has elapsed, the process proceeds to the unevenness two steps (steps S14.6 to S14.7).

  In the pressurization control of step S14.4 of the twice cooking step, the pressure is controlled to the set pressure shown in Table 1 according to the set pressure in the boiling maintenance step. Here, the set pressure in the unevenness process is equal to or less than the set pressure in the boiling maintenance process. In addition, the higher the set pressure in the boiling maintenance process, the higher the set pressure in the boiling maintenance process. The higher the set pressure in the boiling maintenance process, the more motivated the menu is selected. This is because if the pressure is lowered as the set pressure in the boiling maintenance process becomes higher, the feeling of mochi between the high and low setting pressures in the boiling maintaining process becomes the same, and the feeling of mochi as expected cannot be obtained. In addition, the set pressure value of Table 1 is an example, is not limited to this, and should be changed according to the type, capacity, and place of use of the rice cooker.

  Moreover, as shown in Table 2 and Table 3, the time from the end of the boiling maintenance process to the second cooking, and the second cooking time are set according to the menu. Here, the time from the end of the boiling maintenance process to the second cooking, the longer the time of the second cooking, the longer the mochi mochi of the menu, the longer the mochi mochi is from the end of the boiling maintenance process to the second cooking This is because, if the cooking time of 2 times is shortened, the feeling of glutinousness will be the same on the low-moistening menu and the high-moistening menu, and the feeling of glutinousness as expected cannot be obtained. In addition, the setting pressure value and time of Table 2, Table 3 are examples, and are not limited to this, It should be changed according to the model, capacity | capacitance, and use place of a rice cooker.

  In the unevenness 2 process, pressure reduction control is performed in step S14.6. In step S14.7, it is determined whether a predetermined transition time has elapsed. If the transition time has not elapsed, the decompression control is continued, and if it has elapsed, the unevenness 2 process is terminated, the rice cooking end process of step S14.8 is performed, and the process proceeds to the heat retention process of step 15.

  As shown in the flowchart of FIG. 5, first, the microcomputer 8 sets the pressure upper limit value A and the pressure lower limit value B in step S <b> 20 in the unevenness 1, unevenness 2, and pressure reduction control in the rice cooking end process. To do. The pressure upper limit value A and the pressure lower limit value B are set based on a data table stored in the microcomputer 8. This data table is usually a pressure upper limit value A and a pressure lower limit value B set for each process of Murashi 1, Murame 2, and the end of rice cooking in each of the rice cooking menus of mash, soft rice, quick rice, and brown rice. (AD value).

  Next, the microcomputer 8 takes in the AD value C corresponding to the voltage value output from the pressure sensor 13 in step S21. This AD value C represents the current pressure value in the inner pot 2. In step S22, it is determined whether or not the current value C of the pressure sensor 13 is equal to or lower than the pressure lower limit value B. If the current value C is equal to or lower than the pressure lower limit B, it is determined in step S23 whether or not the motor position of the stepping motor 23 is located at the MAX point (position detection). If it is not the MAX point, the stepping motor 23 is rotationally driven in the normal rotation direction in step S24, and if it is the MAX point, the stepping motor 23 is turned off in step S26.

  In step S25, when the condition for ending the pressure reduction control is satisfied, the pressure reduction control is finished and the process proceeds to the next step. If the decompression control is not terminated, the process returns to step S21.

  As described above, when the stepping motor 23 is rotationally driven in the forward rotation direction, the arm portion 22 is rotated, and the pressing portion 21b of the closing valve pressing portion 21 is pushed down in the closing direction. The pressing part 21b presses the closing valve 20b downward via a spring 26 having a predetermined elastic force attached to the lower surface. At this time, the closing valve 20b is applied with a pressing force by the compressed spring 26 and closes the exhaust port 24. As a result, the inside of the inner pot 2 is sealed and pressurized until the pressure lower limit B is reached.

  On the other hand, if the current value C of the pressure sensor 13 is greater than or equal to the lower pressure limit B (NO) in step S22, whether or not the current value C of the pressure sensor 13 is greater than or equal to the upper pressure limit A in step S27. Judging. When the current value C of the pressure sensor 13 is not equal to or higher than the pressure upper limit value A (in the case of NO), the stepping motor 23 is turned off in step S28, and the process proceeds to step S25. Thereby, the closing valve 20b is maintained in a state where a pressing force is applied by the spring 26. As a result, the pressure in the inner pot 2 is maintained at the pressure lower limit B or higher and the pressure upper limit A or lower.

  In step S27, when the current value C of the pressure sensor 13 is equal to or higher than the pressure upper limit value A (in the case of YES), it is determined whether or not the micro switch 33 is turned on in step S29 shown in FIG. If not, the process proceeds to step S30. In step S30, it is determined whether or not the motor position of the stepping motor 23 is at the zero point (position detection). If it is not the zero point, in step S31, the stepping motor 23 is driven to rotate 125 ms in the reverse direction, is turned off for 3.4 s, and proceeds to step S25 (shown in FIG. 5).

  That is, when the stepping motor 23 is rotationally driven in the reverse direction, the arm portion 22 is rotated counterclockwise, and the pressing portion 21b of the blocking valve pressing portion 21 is pressed upward by the spring 26 and moved in the opening direction. To do. At this time, since the pressing force applied by the spring 26 is reduced, the blocking valve 20b is pressed upward by the steam in the inner pan 2 in a high pressure state. As a result, the exhaust port 24 is opened, and the pressure is gradually reduced (released) until the pressure in the inner pot 2 becomes equal to or lower than the pressure upper limit value A. Further, in step S31 and S32, the stepping motor 23 is driven to rotate 125 ms in the reverse direction and turned off for 3.4 seconds, so that the pressure can be reduced stepwise. Further, the amount of decompression can be adjusted by adjusting the rotational drive time of 125 ms.

  If the motor position is at the zero point in step S30, the stepping motor 23 is turned off in step S34, and the process proceeds to step S25. If the micro switch 26 is turned on in step S29, the current position of the stepping motor 23 is reset to the zero point in step S32. In step S34, the stepping motor 23 is turned off, and the process proceeds to step S25. Thus, even when the zero point is shifted due to slippage generated in the stepping motor 23, accurate control can be performed by newly setting the zero point.

  In the above embodiment, the pressure reduction after the boiling maintaining process is performed by the operation of the pressure adjusting device 15, but as shown in FIG. 7, the pressure adjusting device 15 is not operated in step S14.1 of the unevenness process 1. Alternatively, the current to the induction heating coil 9 may be turned off to perform natural pressure reduction. By reducing the pressure by natural pressure reduction, without complicated control, between the pressure adjusting ball 17 and the opening 16, between the closing valve 20 b and the exhaust port 24 of the pressure adjusting device 15, and between the inner lid 11 and the inner pot 2. It is possible to blow off excess moisture through such a small gap. Other steps are the same as those in the embodiment of FIG. However, the pressurization control in step 14.4 of the twice-cooking process in FIG. 7 is not only control for setting the pressure value by operating the pressure regulator 15 and pressurizing to that pressure value, but simply increasing the internal pressure by heating. Control may be performed.

  Further, the pressure adjusting device 15 of the above embodiment has a mechanism for increasing / decreasing the pressing force by the spring 26 using the stepping motor 23, but not limited to this, the pressing portion of the closing valve pressing portion 21 using the solenoid. A mechanism for moving 21b up and down may also be used.

  Further, the pressure adjusting means of the present invention is not a type that increases or decreases the pressing force of the closing valve by the spring as in the pressure adjusting device 15 of the above-described embodiment, but is a size that blocks each of the two exhaust holes provided in the inner lid. The pressure-reducing ball may be of a type that includes two pressure-regulating balls having different pressures, and one or both of them are sequentially retracted by a solenoid.

Schematic of a pressure rice cooker. Sectional drawing of a pressure regulation apparatus. The flowchart which shows the rice cooking process of a pressure rice cooker. The flowchart which shows 1st Embodiment of the operation | movement of the uneven process between a cooking process and a heat retention process. The flowchart of pressure reduction control. FIG. 6 is a flowchart of pressure regulation control following FIG. 5. FIG. The flowchart which shows 2nd Embodiment of operation | movement of the uneven process between a cooking process and a heat retention process.

Explanation of symbols

1 pressure cooker 2 inner pot 6 induction heating coil (heating means)
8 Microcomputer (control means)
11 Inner lid 15 Pressure regulator (pressure adjusting means)

Claims (8)

An inner pot that contains rice cooking ingredients and is sealed with an inner lid;
Heating means for heating the pan;
Pressure adjusting means for adjusting the pressure in the inner pot;
The heating means is controlled to perform preheating, boiling, boiling maintenance, and uneven rice cooking processes, and the pressure adjusting means is operated to increase or decrease the pressure in the inner pot in the rice cooking process. In a pressure cooker equipped with a control means,
The said control means operates the said pressure adjustment means after completion | finish of a boiling maintenance process, pressure-reduces the pressure in the said inner pot, and pressurizes again at the time of the unevenness process, The pressure rice cooker characterized by the above-mentioned.   The pressure rice cooker according to claim 1, wherein a pressure value reduced after the boiling maintaining step is equal to or lower than a pressure value controlled in the unevenness step.   The pressure rice cooker according to claim 2, wherein the pressure value to be reduced after the boiling maintaining step is substantially atmospheric pressure.   The pressure value to be repressurized during the unevenness process is low when the pressure value controlled in the boiling maintenance process is low, and is high when the pressure value controlled in the boiling maintenance process is high. To pressure cooker in any one of 3. An inner pot that contains rice cooking ingredients and is sealed with an inner lid;
Heating means for heating the pan;
Pressure adjusting means for adjusting the pressure in the inner pot;
The heating means is controlled to perform preheating, boiling, boiling maintenance, and uneven rice cooking processes, and the pressure adjusting means is operated to increase or decrease the pressure in the inner pot in the rice cooking process. In a pressure cooker equipped with a control means,
The control means naturally depressurizes the pressure in the inner pot after the boiling maintenance step, and pressurizes again during the unevenness step,
A pressure rice cooker that is pressurized again during the unevenness process is low when the pressure value controlled in the boiling maintenance process is low and high when the pressure value controlled in the boiling maintenance process is high. .   The pressure rice cooker according to any one of claims 1 to 5, wherein a pressure value to be pressurized again during the unevenness process is equal to or less than a pressure value controlled in the boiling maintenance process.   The pressure rice cooker according to any one of claims 1 to 6, wherein the time from the end of the boiling maintenance step to the time of pressurization again during the unevenness step is changed according to the rice cooking menu.   The pressure rice cooker according to any one of claims 1 to 7, wherein the time for pressurizing again during the unevenness process is changed according to a rice cooking menu.

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