JP4663347B2 - Pressure cooker - Google Patents

Description

  The present invention relates to a pressure-type rice cooker that cooks delicious rice in a short time by cooking rice in a pressurized state.

  A pressure-type rice cooker is generally added in the water absorption process in which water is absorbed into the rice in the pan, the startup process in which the heating means is brought to full power after water absorption, the temperature is rapidly heated and raised to the boiling state, and the above process is added. The rice is cooked through each step of a boiling maintenance process that keeps boiling and maintaining rice in a pressed pan, and a non-uniform rice polishing process after the boiling maintenance process.

  The feature of this rice cooker is to shorten the rice cooking time by increasing the pressure in the pan during rice cooking, especially before or during boiling, and allowing water to penetrate into the rice grains in a short time by the synergistic effect of heating and pressure. As a result, it is about to cook soft rice.

  In recent rice cookers, an induction heating coil is attached to the outer periphery of the pan, and a rice cooker using the eddy current generated by this coil, a so-called IH rice cooker, has become the mainstream. However, because this rice cooker has a structure that heats the pan itself, the rice near the inner wall of the pan is heated enough, but it is in the upper center from the center of the pan away from the inner wall Rice may be underheated and uneven cooking may occur.

  In addition, the hot plate rice cooker, which uses a different method from the IH rice cooker and closely contacts the bottom of the pan with a hot plate equipped with a commercially available heater, heats the entire pan bottom with the heater. Since the bottom is intensively heated, cooking unevenness occurs in the pan, and the top surface of the rice when cooked becomes a mountain shape, and the whole may not be cooked uniformly.

  Therefore, in order to overcome the problems of such rice cookers, the present applicant has made various improvements to this type of rice cooker and has filed numerous patent applications for the results thus far (for example, the following patents). References 1 and 2).

  The rice cooker disclosed in the following Patent Document 1 shortens the rice cooking time and makes the cooked state good, a pan containing the rice to be cooked, a heating source for heating the pan, It is equipped with a pressure device that adjusts the pressure, and by this pressure device, the pressure state in the pan is maintained at a predetermined pressure in a series of rice cooking processes of the preheating process, the cooking process, and the boiling process, and water absorption of rice in the preheating process is performed. The water absorption and heat conduction in each process of cooking, boiling and boiling are improved.

Moreover, the rice cooker disclosed by the following patent document 2 is equipped with a control means, and during the boiling maintenance process in which the to-be-cooked rice in the pan reached the boiling temperature by this control means, the pressure valve is opened by a pressure mechanism. By controlling to change the pressure in the pot during boiling, the rice grains are stirred and danced vigorously by boiling phenomenon, so-called bumping phenomenon, and cooked.
JP-A-6-22710 (FIG. 1, paragraphs [0005] to [0009]) JP 2004-81824 A (FIG. 2, summary)

  According to these rice cookers, delicious rice can be cooked. However, further improvements were discovered as a result of further research and development. Therefore, the present invention relates to an improvement of the rice cooker, and the object of the invention is to sufficiently stir the rice during boiling so that the rice can be cooked evenly and the top surface of the cooked rice is flat. It is providing the rice cooker which can show | play the visual delicious effect.

  In addition, the other object of the present invention is that, particularly when the amount of cooked rice is large, uneven cooking is likely to occur, and the top surface of the cooked rice is not easily flattened. The object is to provide a rice cooker in which the top surface of the rice is flat.

In order to achieve the above-mentioned object, the pressure rice cooker according to claim 1 of the present application is a pan that houses a cooked rice containing water and rice, and a heating means that heats the cooked rice in the pan. A lid for closing the opening of the pan, a pressure valve for communicating or shutting off the inside of the pan and the outside air so that the pressure in the pan is substantially constant, and forcing the pressure valve in association with the pressure valve A pressure-type rice cooker comprising a pressure valve opening mechanism that automatically opens, and a control means that controls the heating amount of the heating means and controls the opening and closing of the pressure valve, wherein the control means includes: It has a process of controlling to move to a heat retaining step through a boiling maintaining step of maintaining the inside of the pan at a constant pressure after the end of the rising step of rapidly heating the cooked rice, and during the boiling maintaining step, co when intermittently operated at full power the heating means to control the heating amount , Characterized by having a process of heating the object to be cooking object by activating the heating means at full power while the pressure valve is opened.

The invention of claim 2 of the present application relates to a pressure type rice cooker according to claim 1, wherein the control means, the time for the pressure valve during the boiling-preserving process in an open state at a predetermined time The pressure valve is closed after the time for setting and opening is completed.

Moreover, invention of Claim 3 of this application is related with the pressure type rice cooker of Claim 2, and the said control means intermittently makes the said to-be-cooked rice by the said heating means after the said pressure valve is obstruct | occluded. The inside of the pan is pressurized to a constant pressure by heating at full power, and this pressure is maintained for a predetermined time after reaching the constant pressure.

The invention of claim 4 of the present application relates to a pressure type rice cooker according to claim 1, wherein said control means, said in the pot boiling maintain process and the pressure valve is forcibly opened The pressure valve is controlled so as to maintain the pressure in the pan at 1.1 to 1.4 atm.

Moreover, the invention according to claim 5 of the present application relates to the pressure-type rice cooker according to claim 2, wherein the pressure in the pan is atmospheric pressure during the time during which the pressure valve is opened during the boiling maintaining step. characterized in that it is configured to decrease to near.

The invention of claim 6 of the present application relates to a pressure type rice cooker according to claim 2, the number of times that the pressure valve during the boiling-preserving process the opened state is set to 1 to 10 times It is characterized by.

The invention according to claim 7 of the present application relates to the pressure rice cooker according to claim 1, wherein the lid includes boiling detection means for detecting a boiling state of the cooked food , and the control means includes: wherein comprising a boiling detection means timer for counting a predetermined time after boiling detection by actuates the pressure valve opening mechanism after the count expiration of the timer, characterized in that for opening the pressure valve.

Moreover, invention of Claim 8 of this application is related with the pressure type rice cooker of Claim 7, The said pan is provided with the rice cooking amount detection means which detects the amount of rice cooking in the said pan, The said control means is the said Rice cooking amount storage means for storing the rice cooking amount detected by the rice cooking amount detection means is provided, and during the boiling maintenance step, the heating means is operated intermittently at full power based on the rice cooking amount data by the rice cooking amount storage means. The amount of cooking is controlled, and when the amount of cooked rice is “large”, heating by the heating means is started at full power during the predetermined time counting of the timer, and at least when the amount of cooked rice is “small” It is set so that the heating by the heating means is started at full power at or before the timer finishes counting the predetermined time.

Moreover, invention of Claim 9 of this application is related with the pressure type rice cooker of Claim 1, and the said pressure valve is a pressure hole which connects the inside of the said pan and external air, and the said boiling maintenance process during heating of the cooking object is composed of a ball for closing the pressure hole, upon opening of the pressure valve is adapted to open the pressure hole to forcibly move the ball by the pressure valve opening and closing mechanism It is characterized by.

The invention of claim 10 of the present application relates to a pressure type rice cooker according to claim 9, the opening area of the pressure hole, characterized in that it is a 6mm ² ~18mm ^2.

The invention described in claim 11 of the present application relates to the pressure rice cooker described in claim 1, characterized in that a filter is detachably attached to the lower part of the pressure valve.

  According to invention of Claims 1-3, after completion | finish of the rise process which heats a to-be-cooked rice rapidly, a heat retention process is performed through the boiling maintenance process which hold | maintains the inside of a pan at a fixed pressure, Comprising: By opening the pressure valve during the process, the pressure in the pot is drastically reduced to stir the rice grains, and the rice grains in the center of the pot and the rice grains in the inner wall are mixed and in the pot The whole rice grain can be heated uniformly and can be cooked evenly.

In particular, during the boiling maintenance process, the heating means is operated intermittently to control the amount of heating, but when the pressure in the pan drops when the pressure valve is opened, the cooked rice is heated at full power. The steam is generated more rapidly and rapidly, the rice grains in the pan are further stirred, the whole rice grains in the pan are uniformly heated, and a hole of a predetermined size, so-called crab hole, A so-called steam-hole is formed, and it looks visually delicious.

In addition, the pressure valve is opened during the boiling maintenance process, and the cooked rice is heated at full power at the time of opening, but since a large amount of steam is generated at this time, a constant pressure is immediately applied after the pressure valve is closed. Therefore, heating is continued while maintaining the pressure in the pan at a constant pressure during the boiling maintenance step, and the rice without core can be cooked.

Similarly, after the pressure valve is closed, the cooked rice is heated intermittently at full power and pressurized to a certain pressure, and the pressure is maintained for a predetermined time. It can be softened to the part.

  According to the inventions of claims 4 and 5, since the pressure valve is maintained at 1.1 to 1.4 atm when the pressure valve is not opened during the boiling maintenance step, the pressure within the pan is kept within this range. By doing so, the rice grains can be stirred and vigorously stirred by boiling phenomenon (sudden boiling), so that they can be cooked.

  That is, the pressure in the pan within this range is the lowest pressure value that can be sufficiently stirred experimentally and pressure cooked, and the cooked rice jumps out of the pan with a sudden pressure change (pressure drop). It will be the maximum pressure value.

  And the opening time of the pressure valve in the boiling maintenance process is set to the time that the pressure in the pan decreases to atmospheric pressure or close to it, so the pressure in the pan when the safety valve is closed and when it is opened The difference becomes larger, and the rice grain flows in the pan by the larger difference, and the stirring of the rice grain becomes larger and heated more uniformly.

  According to invention of Claim 6, since the opening / closing frequency | count of the pressure valve in a boiling maintenance process was set to 1-10 times, if the residual water in a pan is enough, the stirring effect will increase, so that the frequency | count increases. However, since the amount of residual water decreases, the number of times is good in order to obtain sufficient stirring. Incidentally, if the pressure valve is opened and closed once or twice, a sufficient stirring effect cannot be obtained.

  According to the invention of claim 7, since the first opening operation of the pressure valve during the boiling maintaining step is set after counting for a predetermined time after the boiling detection by the boiling detection means, the pressure valve is set immediately after the boiling detection. Since it opens after a predetermined time when the boiling state is stabilized instead of opening, it is possible to reduce the pressure at a certain pressure in a certain boiling state, and a stable mixing effect can be obtained at any time from the first opening of the pressure valve. It is done.

According to the invention of claim 8, when the amount of cooked rice is “large” , the heating is started at full power during the above-mentioned predetermined time count, and when the amount of cooked rice is “small”, the predetermined time is Since it starts heating at full power at the end of the count or until then, it corresponds to a program that controls the amount of heating at the time of boiling according to the amount of rice cooked to obtain delicious rice. When the pressure valve is opened, the cooked rice can always be heated at full power, and the pressure can be reduced at once to achieve the mixing effect.

  According to the invention of claim 9, when the pressure in the pan is lowered, the ball is separated from the pressure hole, and the pressure in the pan is released from the pressure hole to the outside air at once, but the opening area of the pressure hole is increased, By shortening the pressure valve opening time and setting the pressure in the pan higher than atmospheric pressure, when the pressure valve is opened, the high pressure in the pan is released from the pressure hole with a large opening area at once. Efficient mixing is performed by a synergistic effect of the large opening area and heating of the cooked rice when the pressure valve is opened.

According to invention of Claim 10, the pressure adjustment in a pan can be smoothly performed by setting the opening area of a pressure hole to the range of 6-18 mm < ² >. Note that if this area is increased, the pressure can be quickly released quickly. However, if the area is increased, this is not only dangerous, but moisture is also quickly discharged to the outside, so this range is preferable.

  According to the eleventh aspect of the present invention, the filter is provided at the lower part of the pressure valve, so that the rice grains flowing at once in the pan when the pressure valve is opened are blocked by the filter so that they are not scattered outside.

  Hereinafter, the best embodiment of the present invention will be described with reference to the drawings. However, the embodiment shown below exemplifies a rice cooker for embodying the technical idea of the present invention, and is not intended to specify the present invention for this rice cooker. Other embodiments within the scope are equally applicable.

  1 is a sectional view of a rice cooker according to one embodiment of the present invention, FIG. 2 is an enlarged sectional view showing a pressure valve opening mechanism of FIG. 1, and FIG. 3 is a block diagram showing a partial timer of the control means of FIG. FIGS. 4 to 7 are control flowcharts of the rice cooker, and FIG. 8 shows the pressure in the pan, the pan bottom temperature, the steam temperature, the opening / closing timing of the pressure valve, and the heating timing of the heating means in each process from the start of rice cooking to the heat retention. FIG. 9 is an explanatory diagram showing an enlarged part of FIG.

  The rice cooker of the present invention has a plurality of rice cooking courses depending on the type of rice and the state of cooking, for example, “white rice / normal”, “white rice / sushimeshi”, and “brown rice / normal”. In addition to this basic rice cooking course, it also has other courses such as “white rice / high speed”, “white rice / application”, and “rice porridge”. In the present embodiment, a “rice cooked rice / normal” rice cooking course that is most frequently used among these rice cooking courses will be described.

  First, the structure of the rice cooker will be described.

  1 and 2, (1) is a rice cooker body, (2) is a pan made of aluminum and stainless clad material for containing water and rice, (3) is a case for storing a pan (2), (4 ) Is a heating means attached to the outer wall and the outer bottom wall of the case (3). For example, an induction coil is used as the heating means (4).

  (5) is an openable / closable lid that covers the opening (6) of the pan (2), and comprises a detachable inner lid (7) provided on the lower side and an outer lid (8) provided thereon. Is done.

  As shown in FIG. 2, the inner lid (7) is provided with a pressure valve (14), a valve seat (10) having a pressure hole (9), and pressure on the valve seat (10) by its own weight. An opening / closing mechanism (18) including a metallic ball (11) that closes the hole (9) and a cover (12) that covers the ball (11) is provided. The pressure valve (14) moves or leaves the ball (11) on the pressure hole (9) depending on the balance between the pressure in the pan (2) and the weight of the ball (11). ) Is moved to open and close the pressure hole (9).

  In addition, when the inside of the pan (2) is abnormally pressurized to the inner lid (8), for example, when the pressure valve (14) fails to open during cooking, the pressure in the pan is released. A safety valve (9a) is provided (see FIG. 1).

  As shown in FIGS. 1 and 2, a plunger (17) is attached to the pressure valve (14) in the outer lid (8), and this plunger (17) is controlled by the control means (20). The That is, when the plunger (17) does not receive the output from the control means (20), the rod (17a) protrudes from the cylinder (17b) and the ball (11) on the pressure hole (9) is moved to the pressure hole ( 9) Press in the lateral direction to forcibly open the pressure hole (9). When the plunger (17) receives the output of the control means (20), the rod (17a) is drawn into the cylinder (17b). At this time, the ball (11) returns to the pressure hole (9) by its own weight and closes the pressure hole (9).

  In this way, the plunger (17) operates as a pressure valve opening mechanism, and this opening operation forcibly reduces the pressure in the pan that has been pressurized during the rice cooking process.

  The outer lid (8) has a steam port (15) through which the inside of the pan (2) communicates with the atmosphere via the pressure hole (9), and the pressure and steam in the pan (2) are released into the atmosphere. ing.

  As shown in FIG. 1, the rice cooker body (1) includes selection means (16) for selecting the above-described rice cooking course.

  As is well known, the control means (20) includes hardware constituted by a CPU, a ROM, a RAM, and the like, and software for executing the contents of a flowchart to be described later.

  At the bottom of the pan (2), as shown in FIG. 1, a temperature sensor (19b) for detecting the pan bottom temperature that also functions as rice cooking amount detection means, and a lid (8) at an appropriate position. A steam sensor (19a) serving as a boiling detection means for detecting the steam temperature is attached, and the outputs of the sensors (19a) and (19b) are sent to the control means (20). In addition, since it is already well-known to detect the amount of rice cooking in a pan by the output of a temperature sensor, detailed description is omitted.

  As shown in FIGS. 1 and 2, a filter (21) that is detachably attached to the valve seat (10) and has a plurality of small holes is attached to the lower portion of the pressure valve (14). By attaching this filter (21), it is possible to prevent the rice grains flowing in the pan at a time when the pressure valve (14) is opened from being blocked by the filter (21) and released to the outside air.

  The control means (20) will be described with reference to FIG.

  (22) is a predetermined time (t1 = 12 seconds) when the steam sensor (19a) detects that the steam temperature generated from the inside of the pan has reached 75 degrees and receives a signal indicating the boiling start temperature (t1 = 12 seconds). It is the 1st timer which counts.

  (23) is a second timer which receives the temperature signal at the start of boiling by the steam sensor (19a) and counts (t1) + (opening time T) = 16 seconds.

  (24) is a third timer that counts a predetermined time (t3 = 32 seconds) after a predetermined time (12 seconds) is counted by the first timer (22), and (25) is a start of boiling by the steam sensor (19a). It is a 4th timer which time-measures the time (t4) until the heating start by the heating means (4) after transfering to a boiling maintenance process in response to a temperature signal.

  (26) is a depressurization timer that counts the opening time (T = 4 seconds) of the pressure valve (14) after the first timer (22) has counted a predetermined time (t1 = 12 seconds).

(27) is a rice cooking amount storage means for determining the amount of rice cooking based on the temperature detected by the temperature sensor (19b) and storing the determined rice cooking amount data, and (28) is when boiling is detected by the steam sensor ( 19a ). In response to the above signal, the calculation means calculates the rice cooking amount data stored in the rice cooking amount storage means (27), and specifically sets the time (t4) until the fourth timer (25) starts heating. It becomes the basis to do.

  (29) is a heating time setting means for setting the heating time based on the output of the calculating means (28), and the output of the calculating means is the time (t4) until the start of heating by the fourth timer (25) according to the amount of cooked rice. Variable. For example, when the amount of cooked rice is “large”, the heating amount up to the point of time synchronized with the count of the opening time (T = 4 seconds) is set large, and (t4a) is set to 3 seconds. In the case of “medium”, the heating amount is also set to a medium level, and (t4b) is set to 6 seconds. In the case of “small”, similarly, the heating amount is set small, and (t4c) is set to 9 seconds.

  That is, the time of (t4) counting until the heating start of the 4th timer (25) counted after boiling detection is 3 seconds (rice cooking amount "large")-9 seconds (rice cooking amount "small"), (t4) The heating time until the count of the opening time (T = 4 seconds) of the pressure valve (14) after counting is 7 seconds (rice cooking amount “large”) to 13 seconds (rice cooking amount “small”).

  Of course, the cooked rice amount storage means (27) naturally has a plurality of fixed data such as between “large” and “medium” and between “medium” and “small”.

  Next, a rice cooking process is demonstrated mainly with reference to FIGS. In this embodiment, a case where the “white rice / normal” course is selected in the cooking rice course will be described.

  When the rice cooking course of “white rice / normal” is selected by the selection means (16) in FIG. 1, the pot (2) is heated by the heating means (4) and the cooked rice consisting of rice and water in the pot is heated. Is done. At this time, the rod (17a) of the plunger (17) is at the right position in FIG. 2 and the ball (11) is pushed to open the pressure valve (14). In this state, the rice water absorption process is executed. (S2 to S4).

  In this water absorption step, the heating amount of the heating means (4) is controlled by the control means (20) so that the pan bottom temperature is maintained at about 55 degrees, and this process is maintained for 15 minutes as shown in FIG. S5).

  When the water absorption step (S5) for 15 minutes is completed, the heating means (4) is set to full power, and the process proceeds to a rising step of rapidly heating the cooked rice as shown in FIG. 8 (S6). In this start-up process, the rod (17a) is separated from the ball (11) and the pressure valve (14) is closed, the amount of rice cooked is determined at the stage of rapid heating, and the rice cooking amount data is stored as the rice cooking amount storage means (27). (S7-S8). Then, the pressure valve (14) is closed (S9).

In this start-up step, the pan bottom (inside the pan) temperature and the steam temperature are increased by full power heating together with the closing of the pressure valve (14) (S9), and the pan internal pressure is rapidly increased to 1.2 atm. And if it detects that the steam sensor (19a) has reached 75 degrees (the bottom temperature by the temperature sensor (19b) is 105 degrees) which becomes the boiling temperature (large) of the cooked rice (S10 to S11), FIG. As shown, it moves to a boiling maintenance process, operates a heating means (4) intermittently, and maintains the pressure in a pan at 1.2 atmospheres (S12-S13). However, 1.2 atmospheric pressure described here is a pressure at which the best result was obtained experimentally, and the pressure in the pan is not limited to 1.2 atmospheric pressure, for example, 1.1 atmospheric pressure to 1.4 atmospheric pressure. Even if the pressure is changed within the range of atmospheric pressure, the same good effect as that at 1.2 atmospheric pressure can be obtained.

  Here, the operation in the boiling maintaining step will be described in more detail with reference to FIGS.

  When the steam sensor (19a) detects the boiling temperature ((K) = 75 degrees), the IH power of the heating means (4) is set to “0” (see FIGS. 8 and 9) (S14), The timer (22) starts counting for a predetermined time (t1 = 12 seconds) (S16), and at the same time, the second timer (23) opens the pressure valve (14) for a predetermined time of the first timer (22) (T ) (= 4 seconds) is set (t2 = 16 seconds). That is, at the same time when the second timer (23) starts counting for 16 seconds, the first timer (22) counts 12 seconds immediately after the second timer (23) starts counting (S17 to S18). Moreover, the 3rd timer (24) which sets the opening-and-closing period of a pressure valve (14) with a 2nd timer (23) is set to 32 seconds (S19).

  As a result, the pressure valve (14) is closed while the first timer (22) after the steam sensor (19a) detects the boiling temperature counts for 12 seconds, and the rod (17a) is closed after counting for 12 seconds. Operates and opens the pressure valve (14) for 4 seconds of opening time (see FIGS. 8 and 9).

  As described above, when the boiling is detected, the pressure in the pan is 1.2 atm. The pressure is maintained for 12 seconds after the boiling is detected, and after 12 seconds, the pressure valve (14) is opened for 4 seconds. Release the pressure in the pan at once. When the pressure valve (14) is opened at the time when the above-mentioned 12 seconds have elapsed, the heating means (4) is used to heat the cooked rice in the pan (2) more vigorously.

  Here, the heating timing of the heating means (4) when the pressure valve (14) is opened will be described in detail with reference to FIGS.

  When boiling is detected by the steam sensor (19a), the heating amount (heating time (tQ)) in the boiling maintenance step is set according to the amount of cooked rice (S20). The setting of this heating time (tQ) is determined based on the rice cooking amount data determined at the start-up process, the heating time (tQa) when the rice cooking amount is “large” is long, and the rice cooking amount is “medium”. In this case, the heating time (tQb) is set to be medium, and the heating time (tQc) when the amount of cooked rice is “small” is set short.

  The fourth timer (25) is a time obtained by subtracting the heating time (tQ) from the set time (16 seconds) of the second timer (23) that starts counting after the boiling detection by the steam sensor (19a) (t4 = 3-9 seconds) is counted (S21). When the amount of cooked rice is "Large", heating is performed after a predetermined time (t4a = 3 seconds) after detection of boiling, and when the amount of cooked rice is "Medium", it is boiled. Heating is performed after counting for a predetermined time (t4b = 6 seconds) after detection. When the amount of cooked rice is “small”, heating is performed after counting for a predetermined time (t4c = 9 seconds) after detection of boiling.

  Next, the cooked rice amount data is referred to (S22), and when the cooked rice amount is “medium”, the fourth timer (25) that starts counting after the boiling detection performs the counting for 6 seconds (S23 to S25). During this time, the pressure valve (14) is closed and heating of the heating means (4) is also stopped.

  When the fourth timer (25) finishes counting for 6 seconds (S26), the heating means (4) is operated at full power, and heating is performed for the heating time (tQb = 10 seconds) (S27 to S28).

  Here, the time when the heating time (tQb) is counted coincides with the time when the first timer (22) is counted for 12 seconds (S29).

The count-up output of the first timer (22) starts the 4-second count of the decompression timer (26) and operates the rod (17a) to move the ball (11) away from the pressure hole (9). Open the pressure valve (14). (S31). Since the opening time of the pressure valve (14) is shorter than 10 seconds of (tQb), the heating means (4) is heated at full power while the pressure valve is opened. Then, by opening the pressure valve (14) for 4 seconds, the pressure in the pan suddenly drops to about 1 atm (S32). At this time, a large amount of steam can be generated by heating the cooked rice with full power when the pressure valve (14) is opened, so that the cooked rice in the pan (2) can be stirred more vigorously.

That is, the opening time of the pressure valve (14) for 4 seconds and the full power heating of the heating means (4) when the pressure valve is opened are a rapid pressure drop from 1.2 atm to 1.0 atm and a large amount It causes the generation of water vapor, and the rice and water in the pan flow greatly, that is, vigorously stirred.

  Of course, the opening area of the pressure hole (9) at this time is also set so as to promote the rapid pressure drop, the opening area (A), the opening time of the pressure valve (T = 4 seconds), and the pressure in the pan ( With (P), if (P) is large, (A) is increased, and the opening time (T) is set such that steam (moisture) in the pan is not released into the outside air more than necessary.

  If the opening time (T) is very short, for example, about 1 second, it cannot be reduced from 1.2 atmospheres to about 1.0 atmosphere at a stretch. Although it can be performed, it is not possible to secure the amount of water in the pan necessary for releasing a large amount of steam (water) in the pan and performing several pressure drops.

  Therefore, the opening time (T) = 4 seconds of this example is that, as a result of the experiment, in addition to increasing the opening area (A) of the pressure hole (9), the pressure in the pan is maintained at 1.2 atm. It was found that the pressure valve (14) was sometimes opened and the pressure was reduced suddenly, and this pressure reduction and the pressure maintenance of 1.2 atmospheres were repeated up to 10 times.

The opening area of the pressure hole (9), 6~18mm ^2, especially 12 mm ² (diameter about 3.6mm pressure hole (9)) and preferably before and after this value. If this area is increased, the pressure can be rapidly released at once. However, if the area is increased, not only is this dangerous, but moisture is also quickly discharged to the outside, so this value is preferable.

  The number of times the pressure valve is opened and closed is preferably 1 to 10 times. If the remaining water in the pan is sufficient, the stirring effect increases as the number of times is increased. However, at least once, there is sufficient residual water and stirring occurs. And the maximum number of times of opening and closing that the amount of residual water required for stirring is obtained is 10 times.

  When the opening time (T) = 4 seconds elapses (S33), the pressure valve (14) is closed and the power of the heating means (4) is set to “0” (S34 to S35). Increase the pressure in the pan again.

  When the pressure in the pan rises, the fourth timer (25) starts counting, and when the time of the above-mentioned rice cooking amount “medium” (t4b = 6 seconds) is counted, the heating time (tQb = 10 seconds) Heat by the intermediate heating means (4).

  Thereafter, the opening and closing of the pressure valve (14) is repeated six times (S36), and after that, the heating means is “0” during the above-mentioned (t4b = 6 seconds) with the pressure valve (14) closed ( During tQb = 10 seconds), the boiling state is maintained while heating at “full power”, and when the pan bottom temperature reaches 130 ° C., the process shifts to the uneven process 1.

  The unevenness process 1 is a process of steaming while maintaining a relatively high temperature at the bottom (inside of the pot) (S37).

  After the unevenness process 1 is completed, the process proceeds to a re-cooking process in which the cooked rice is heated by the heating means for a slightly longer time to eliminate excess moisture (S38).

  After the end of the additional cooking process, the process proceeds to the steaming unevenness process 2 at a temperature slightly lower than the temperature in the pan of the aforementioned unevenness process 1 (S39).

  Then, it transfers to a heat retention process and complete | finishes a series of rice cooking processes (S40).

  If the cooked rice amount data is “large” in (S22) described above, the process proceeds to (S41), and the fourth timer (25) that starts counting after detection of boiling counts for 3 seconds (S42) and (S43). . During this time, the pressure valve (14) is closed and heating is not performed.

  When the fourth timer (25) counts 3 seconds (S44), full power heating is performed by the heating means, and heating is performed for the heating time (tQa = 13 seconds) (S45 to S46).

  While the counting of (tQa = 13 seconds) is being performed, heating by the heating means is performed, but this heating start time is a stage before the count-up for 12 seconds by the first timer (22). A large amount of cooked rice is sufficiently heated to prepare for opening of the pressure valve (14). After that, the same operation as the above-mentioned rice cooking amount “medium” is performed.

  When the above-mentioned cooked rice amount data is “small” (S47), the fourth timer (25) that starts counting after detecting boiling (t4c = 9 seconds) counts (S48 to S49). During this time, the pressure valve (14) is closed and heating is not performed.

  When the fourth timer (25) counts (t4c = 9 seconds) (S50), full power heating is performed by the heating means, and heating is performed for the heating time (tQc = 7 seconds) (S51 to S52). Thereafter, the same operation as described above is performed.

  As described above, the present invention performs the heat retaining step through the boiling maintaining step for maintaining the inside of the pan at a constant pressure after the end of the rising step for rapidly heating the cooked rice. By opening the pressure valve, the pressure in the pan is drastically reduced to agitate the rice grains, and the rice grains in the center of the pan and the rice grains in the inner wall are mixed to make the whole rice grains in the pan even. Can be heated and cooked evenly.

  In particular, the rice grains in the pan can be stirred more greatly by heating the cooked rice when the pressure in the pan is reduced when the pressure valve is opened, so that the whole rice grains in the pan can be heated uniformly and cooked. A hole of a predetermined size, that is, a so-called crab hole, is formed on the upper surface of the object after steam is removed, which makes it visually delicious.

  In addition, the pressure valve is opened during the boiling maintenance process, and the cooked rice is heated at the time of opening, but the pressure valve is closed when a predetermined opening time elapses. Heating is continued while maintaining the pressure in the pan in the process at a constant pressure, and rice without a core can be cooked.

  Similarly, after the pressure valve is closed, the cooked rice is heated and pressurized to a certain pressure, and the pressure is maintained for a predetermined time, so that the rice grains are sufficiently heated by the pressure and heat to soften to the center of the core. can do. In addition, since the pressure valve is used to maintain the pressure in the pan at 1.2 atm when not opened during the boiling maintenance step, the pressure in the pan is set within this range to sufficiently perform the agitation by bumping. be able to.

  In this embodiment, an induction coil is used as the heating means (4). However, the heating means (4) is not limited to such a heating means, and a heating plate equipped with a heater is attached to the bottom of the pan or other heating method. There may be. Further, the pressure valve opening / closing mechanism may be a mechanically acting mechanism or an electromagnetically acting mechanism as long as the pressure valve can be forcibly opened from the closed state. .

Sectional drawing of the rice cooker which concerns on one Example of this invention, The expanded sectional view which shows the pressure valve opening mechanism of FIG. Block diagram showing a part of the timer of the control means, Control flow chart of rice cooker, Control flow chart of rice cooker, Control flow chart of rice cooker, Control flow chart of rice cooker, Explanatory drawing showing the pressure in the pan in each step from the start of rice cooking to the heat insulation of the rice cooker, the pan bottom temperature, the steam temperature, the opening / closing timing of the pressure valve, the heating timing of the heating means, It is explanatory drawing which expanded a part of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rice cooker body 2 Pan 4 Heating means 9 Pressure hole 11 Ball 14 Pressure valve 15 Pressure valve opening / closing mechanism 16 Selection means 18 Control means 19a Steam sensor (boiling detection means)
19b Temperature sensor (rice cooking amount detection means)
20 Control means

Claims (11)

A pan for containing the cooked rice containing water and rice, a heating means for heating the cooked rice in the pan, a lid for closing the opening of the pan, and the pressure in the pan so as to be substantially constant A pressure valve that communicates or shuts off the inside of the pan and the outside air, a pressure valve opening mechanism that is associated with the pressure valve and forcibly opens the pressure valve, controls the heating amount of the heating means, and A pressure rice cooker comprising control means for controlling opening and closing of the pressure valve,
The control means has a process of controlling to shift to a heat retaining step through a boiling maintaining step of maintaining the inside of the pan at a constant pressure after the end of the rising step of rapidly heating the cooked rice,
During the boiling maintain step, controls intermittent heating amount is operated at full power to the heating means, it is operated at full power the heating means while the pressure valve is in the open state A pressure rice cooker having a process of heating the cooked rice.   The control means sets a predetermined time for the pressure valve to open during the boiling maintenance step, and closes the pressure valve after the time for the open state is over. The pressure-type rice cooker as described in. After the pressure valve is closed, the control means intermittently heats the cooked rice with full power by the heating means to pressurize the inside of the pan to a constant pressure, and after reaching the constant pressure, this pressure is predetermined. The pressure rice cooker according to claim 2, wherein the pressure rice cooker is maintained for a period of time.   The control means is configured to maintain the pressure in the pan at 1.1 to 1.4 atm when the inside of the pan is in a boiling maintaining step and the pressure valve is not forcibly opened. The pressure rice cooker according to claim 1, wherein the pressure valve is controlled.   3. The pressure rice cooker according to claim 2, wherein the time during which the pressure valve is opened during the boiling maintaining step is set so that the pressure in the pan decreases to near atmospheric pressure. 4.   The pressure rice cooker according to claim 2, wherein the number of times the pressure valve is opened during the boiling maintenance step is set to 1 to 10 times.   The lid includes a boiling detection unit that detects a boiling state of the cooked rice, and the control unit includes a timer that counts a predetermined time after the boiling is detected by the boiling detection unit, and the pressure after the timer is counted. The pressure rice cooker according to claim 1, wherein a valve opening mechanism is operated to open the pressure valve. The pan includes rice cooking amount detection means for detecting the amount of rice cooked in the pan, the control means includes rice cooking amount storage means for storing the rice cooking amount detected by the rice cooking amount detection means, and during the boiling maintaining step, Based on the cooked rice amount data by the cooked rice storage means, the heating means is intermittently operated at full power to control the heating amount, and when the cooked rice amount is “large”, the timer is counting for a predetermined time. starting at the heating by the heating means to start at full power, full power heating by the heating means at least the timer until it or some point to end the counting of the predetermined time when the cooking amount "small" in The pressure-type rice cooker according to claim 7, wherein the pressure-type rice cooker is set to perform.   The pressure valve is composed of a pressure hole that communicates the inside of the pan with the outside air, and a ball that closes the pressure hole when the cooked rice is heated during the boiling maintaining step, and the pressure valve is opened when the pressure valve is opened. The pressure rice cooker according to claim 1, wherein the ball is forcibly moved by a valve opening / closing mechanism to open the pressure hole. Opening area of the pressure hole, a pressure type rice cooker according to claim 9, wherein the a 6mm ² ~18mm ^2.   The pressure rice cooker according to claim 1, wherein a filter is detachably attached to a lower portion of the pressure valve.

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