JP2006075654A - Pressure rice cooker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rice cooker for uniformly cooking rice, and making the top face of boiled rice flat to produce a visually delicious taste effect. <P>SOLUTION: This rice cooker includes: a pot 2 storing the prescribed amount of material to be cooked including water and rice; a rice cooker body 1 provided with an opening part for housing the pot and a heating means for heating the material to be cooked in the pot; a lid body 4 covering the pot and the opening part of the rice cooker body; a pressure valve 14 for communicating or blocking between the inside of the pot and the outside air; a pressure valve opening mechanism 18 attached to the pressure valve for forcibly turning the pressure valve from a closed state to an open state; and a control means 20 for controlling the heating amount of the heating means and controlling the opening/closing operation of the pressure valve by the pressure valve opening mechanism. The control means 20 executes control so as to generate a bumping phenomenon inside the pot and agitate rice grains by forcibly opening the pressure valve 14 by the pressure valve opening mechanism and drop the pressure inside the pot boosted in the process of maintaining boiling at least by 0.1 atmosphere or more at once. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

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

  In rice cooking using a pressure rice cooker, a water absorption process for absorbing water into the rice in the pan, a rising heating process for rapidly heating to full power after water absorption to bring it to a boiling state, and in a pressurized pan It is common to finish the cooking through the steps of the boiling maintenance step for keeping rice boiling and the rice boiling after the end of the boiling maintenance step.

  The main feature of rice cooking with a pressure rice cooker is that when cooking rice, especially before starting boiling or during boiling, the pressure in the pan is increased and water is allowed to penetrate into the rice grains in a short time due to the synergistic effect of heating and pressure. The rice cooking time is shortened and, as a result, the rice is cooked soft. This type of pressure rice cooker is disclosed in Patent Documents 1 and 2, for example.

JP-A-6-22710 JP 2001-137113 A

  The most recent rice cookers are so-called IH rice cookers that are heated by eddy current generated by an induction heating coil that heats a pan containing water and rice, but the pan itself has a structure that generates heat. Therefore, although the rice in the area close to the inner wall of the pan is sufficiently heated, the rice in the upper center from the center of the pan away from the inner wall is under-heated and has a structure that tends to cause uneven cooking .

  In addition, when looking at the cooked state with such a rice cooker, the rice near the center of the pan and the upper center (the center of the top surface of the cooked rice) is underheated, so the rice near the inner wall The shape of the top surface of the rice seen when the lid is opened is not a flat surface, it is a dish shape with a lower upper center and a higher upper periphery (near the inner wall of the pan). It lacked a good taste effect. Furthermore, the rice that was under-heated in the upper center part had a core and lacked deliciousness.

  On the other hand, a hot plate rice cooker, which is a different system from the IH rice cooker and in which a hot plate with a heater that has been commercialized for a long time, is in close contact with the bottom of the pan, heats the entire pan bottom with the heater. However, intensive heating at the bottom of the pan causes uneven cooking in the pan, and the top surface of the cooked rice is shaped like a mountain, and the whole is not cooked uniformly.

  Therefore, the present invention has an object to provide a pressure rice cooker that can cook rice evenly and that can provide a visual delicious effect by making the upper surface of cooked rice flat. And

In order to achieve the above object, a pressure rice cooker according to claim 1 of the present invention comprises a pan into which a predetermined amount of cooked rice containing water and rice is charged, an opening for housing the pan, A rice cooker body having a heating means for heating the cooked rice in the pan, a lid for closing the opening of the pan and the rice cooker body, a pressure valve for communicating or blocking the inside of the pan and the outside air, A pressure valve opening mechanism attached to the pressure valve for forcibly opening the pressure valve from a closed state; and controlling a heating amount of the heating means and controlling an opening / closing operation of the pressure valve by the pressure valve opening mechanism A pressure-type rice cooker that performs cooking in a pressurized state during the boiling maintenance step in a series of rice cooking steps,
In the boiling maintaining step, the control means forcibly lowers the pressure in the pan at least 0.1 atm or more by forcibly opening the pressure valve by the pressure valve opening mechanism. It is characterized by controlling the rice grains to stir by generating a bumping phenomenon inside.

  The invention according to claim 2 is the pressure rice cooker according to claim 1, wherein the control means has a sufficient period of moisture in the initial stage of the boiling maintenance process in which the cooked rice in the pan has reached the boiling temperature due to heating. The pressure valve is forcibly opened by a pressure valve opening mechanism.

  The invention according to claim 3 is the pressure rice cooker according to claim 2, wherein the control means is heated in the fully heated state by the heating means during all the steps in the start-up heating process before shifting to the boiling maintenance process. In addition, the pressure valve is controlled not to be opened by the pressure valve opening mechanism so as to increase the pressure in the pan.

  According to a fourth aspect of the present invention, in the pressure rice cooker of the first aspect, the pressure valve is an automatic open / close valve that is automatically opened and closed from a closed state to an open state when the pressure in the pan reaches a predetermined value. And the control means closes the pressure valve by the pressure valve opening mechanism after the initial stage of the boiling maintenance process, and thereafter automatically opens and closes according to the pressure in the pan by the automatic opening and closing valve. The pressure in the pan is made substantially constant.

  According to a fifth aspect of the present invention, in the pressure rice cooker according to the fourth aspect, the automatic valve has a valve hole closed with a ball having a predetermined weight.

  The invention according to claim 6 is the pressure rice cooker according to claim 1, wherein the control means executes an unevenness process after the completion of the rice cooking that has undergone the boiling maintenance process, and then shifts to a heat retaining process, The pressure valve is opened by the pressure valve opening mechanism for a certain period of time immediately after the end of the unevenness process, and the inside of the pan is controlled to be atmospheric pressure at the end of the unevenness process.

  As described above, the present invention increases the pressure in the pan at the time of cooking rice, and lowers the pressure in the pan by communicating the inside of the pan and the atmosphere during the initial stage of the boiling maintenance process. Therefore, when the pressure in the pan is released and the pressure returns to atmospheric pressure, water and rice are stirred in the pan due to bumping phenomenon, and the rice grains in the center side are not placed in a fixed position in the pan. It moves also to the side, and as a result, sufficient heat is applied to the whole rice grain and uniform heating is achieved. And as a result of the heating of a rice grain being averaged, the upper surface of rice becomes flat. In particular, since the pressure in the pan is reduced during the previous stage when there is a sufficient amount of water in the pan in the boiling maintenance step, the rice grains in the pan can be rapidly stirred.

  In addition, if the pressure valve is closed during the start-up heating process before the boiling maintenance process, the pressure in the pan can be increased, and water can penetrate into the rice grains in a short time and delicious rice can be delivered in a short time. Can be cooked. In short, when it is necessary to increase the pressure in the pan, the pressure valve is closed and uniform heating is performed. When the upper surface of the rice is made flat after cooking, the pressure in the pan is released during boiling. And since the pressure valve was opened at the time of the unevenness process (the second half of the unevenness process), when the lid is opened, the inside of the pan becomes the same as the atmospheric pressure, and the opening and closing is easy.

  There is at least a white rice / standard course and a brown rice standard course, and this course is selected by means of selection. In the case of the white rice / standard course, the pressure valve is operated several times during the boiling process and the atmosphere in the pan By connecting and shutting off the pressure valve, the mixing effect of at least one opening of the pressure valve eliminates partial heating, and the top surface can be flattened by adjusting the arrangement of the rice grains. Since the standard course does not connect or shut off several times during the boiling maintenance process, sufficient pressure can be applied to absorb moisture in the brown rice.

In addition, during the brown rice / standard course, the pressure valve is closed during the start-up heating process before the boiling maintenance process so that moisture is absorbed when the amount of heating is the largest, and the rice grains of brown rice that are relatively difficult to absorb can be absorbed in a short time. Can be absorbed.
And, when obtaining rice for sushi and pilaf, if the pressure valve is opened during a series of steps from the boiling maintenance step to the steaming step, the water absorption more than necessary inside the rice grain is suppressed. After cooking, it is easy to grasp as a sushi, and a crisp and crisp rice is obtained.
In addition, the number of times of communication / blocking with the atmosphere in the pan when the white rice / standard course is performed is small when the amount of cooked rice is large, and when the amount is small, it is set to a large number. Prevents rice balls and rice grains from scattering. When the amount of cooked rice is large, it is necessary to stir the rice grains sufficiently during the boiling maintenance process, but considering the spillage of rice balls, the rice top is flattened and cooked by stirring the rice grains while minimizing the number of communication. When unevenness is prevented and the amount of cooked rice is small, the number of times of communication can be increased to further flatten and prevent uneven cooking.

Hereinafter, the pressure type rice cooker which concerns on embodiment of this invention is demonstrated.
FIG. 1 is a flowchart showing an outline of a rice cooking process using a pressure rice cooker according to an embodiment of the present invention (three rice cooking courses of “brown rice / normal rice cooking course”, “white rice / normal rice cooking course”, and “white rice / sushimeshi rice cooking course”). 2 is a partial cross-sectional view of the same-pressure rice cooker (showing a partial cross-sectional view of a lid, a pressure valve, and a pressure valve opening mechanism), and FIG. 3 is a partially enlarged cross-sectional view of FIG. 4 is a partially enlarged view of the pressure valve and the pressure valve opening mechanism), FIG. 4 is a more detailed flowchart of the “brown rice / normal rice cooking course” in the flowchart shown in FIG. 1, and FIG. 5 is a flowchart following the flowchart shown in FIG. 6 is a more detailed flowchart of the “white rice / normal rice cooking course” in the flowchart shown in FIG. 1, FIG. 7 is a flowchart following the flowchart shown in FIG. 6, and FIG. 8 is a flowchart shown in FIG. Fig. 9 is a flowchart following the flowchart shown in Fig. 8, Fig. 10 is a characteristic diagram of "brown rice / normal rice cooking course", and Fig. 11 is "white rice". The characteristic diagram of “Usually Cooking Rice Course”, FIG. 12 is the characteristic diagram of “White Rice / Application (Sushimeshi) Cooking Course”.

  2 and 3, (1) is a rice cooker main body, (2) is a pan made of aluminum and stainless clad material for containing water and rice, and (3) is a case for storing the pan (2). Is attached with heating means (4) (outer bottom wall not shown) by an induction coil together with the outer bottom wall.

  (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.

The inner lid (7) has a valve seat (10) having a valve hole (9), and a metal ball mounted on the valve seat (10) so as to close the valve hole (9) by its own weight ( 11) and a pressure valve (14) comprising a cover (12) covering the ball (11). In the pressure valve (14), the ball (11) is placed on or removed from the valve hole (9) depending on the balance between the pressure in the pan (2) and the weight of the ball (11). Therefore, the valve hole (9) opens and closes depending on whether or not the valve hole (9) is closed by the weight of the ball (11).
Therefore, the opening / closing mechanism (18) of the pressure valve (14) is formed by the valve hole (9), the valve seat (10), the ball (11), and the cover (12).

  Also provided with a safety valve (13) that opens when the inside of the pan (2) is abnormally pressurized (for example, when the pressure valve (14) fails to open during cooking) and releases the pressure in the pan. Yes.

A plunger (17) is attached to the pressure valve (14) in the outer lid (8). The plunger (17) is controlled by the control means (20). That is, when the plunger (17) is in a normal state where the output from the control means (20) is not received, the rod (17a) protrudes from the cylinder (17b) and the ball (11) on the valve hole (9) is valved. Pushing in the lateral direction of the hole (9), the valve hole (9) is forcibly opened. Further, when the plunger (17) receives the output of the control means (20), the rod (17a) is immersed in the cylinder (17b). At this time, the ball (11) returns to the valve hole (9) by its own weight and closes the valve hole (9).
Thus, the plunger (17) operates as a pressure valve opening mechanism, and the pressure valve and the pressure valve opening mechanism are pressure changing means for forcibly lowering the pressure in the pan that has been pressurized during the rice cooking process. Used as

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

Moreover, the rice cooker main body (1) is provided with the selection means (16) for selecting a rice cooking course.
As is well known, the control means (20) includes hardware configured by a CPU, a ROM, a RAM, and the like, and software for executing the contents of a flowchart described later.

Although not shown, a temperature sensor for detecting the temperature at the bottom of the pan is attached to the bottom of the pan, and a steam sensor for detecting the temperature of the steam is attached to the lid (8), and the temperature information is controlled by the control means (20). Configured to be sent to.
Moreover, although not shown in figure, the control means (20) incorporates the clock which functions as various timers, and monitors various elapsed time required in the rice cooking process.

  Next, the function of the rice cooker according to the embodiment of the present invention will be described based on the flowchart shown in FIG. First, the basic function of the rice cooker according to the present embodiment will be described. As shown in FIG. 1, this rice cooker is basically provided with the following three rice cooking courses. These three rice cooking courses are “brown rice / standard (normal) rice cooking course A”, “white rice / standard (normal) rice cooking course B”, and “white rice / applied rice cooking course C”. The person can appropriately select one of these three rice cooking courses by the selection means (16).

  Each of the rice cooking courses A, B, and C basically has a water absorption process for absorbing water below the gelatinization temperature (for example, 55 degrees), a rising heating process for heating water and rice with full heating (full power), and boiling. Boiling maintenance process for maintaining the state, unevenness process 1 (first half of unevenness) performed after completion of boiling maintenance, additional cooking process performed after completion of unevenness process 1, and unevenness process 2 (finishing) Each process in the second half is executed sequentially.

Generally, brown rice has a low water absorption because it does not remove rice bran. On the other hand, white rice has few wrinkles and good water absorption. Therefore, when cooking brown rice, it is necessary to make it easier to absorb water than when cooking white rice as standard (usually as white rice).
Therefore, in the cooking of brown rice, it is basically based on cooking rice so that the pressure in the pan is kept as high as possible from the beginning of rice cooking compared to the cooking of white rice.

On the other hand, when cooking rice for sushi and pilaf, instead of cooking white rice as standard, it is necessary to reduce the amount of water adhering to the periphery of the rice grains after cooking. For this reason, when squeezing and cooking white rice for pilaf, it is preferable to reduce the amount of water absorbed by the white rice, and therefore it is necessary to reduce the pressure in the pan during boiling.
That is, the state of white rice used for squeezing is easier to grip when it is closer to flipping. In addition, the state of the rice grains of white rice used for pilaf is easier to stir the rice grains with rice paddles closer to the flip.
Further, in the case of white rice used for porridge, it is necessary to prevent excessive water from penetrating in order to prevent the white rice from becoming pasty.
Therefore, cooking rice typified by sushi sushi, pilaf, and rice porridge is basically cooked without increasing the pressure in the pan from the beginning of cooking to suppress the amount of water absorbed by the rice.

  The above-mentioned three rice cooking courses implement the above, and each rice cooking course is demonstrated concretely below. As shown in FIG. 1, a pan (2) containing a predetermined amount of water and rice is first housed in a case (3), and the lid (5) is closed. Then, a rice cooking course is selected by the selection means (16) (S1). When the rice cooking course is selected (S2), a high frequency current is applied to the heating means (4) (coil) for heating the outer bottom wall and the outer wall of the case, and an eddy current flows between the pan and the pan generates heat and water. And rice are heated.

  Here, a case where “brown rice / standard (normal) rice cooking course A” is selected by the selection means (16) will be described (S3). As shown in the flowcharts of FIGS. 1A, 4 and 5 and the characteristic diagram of FIG. 10, heating is started by the heating means (4) (S4) and at the same time the pressure valve (14) remains open (plunger). In (17), the rod protrudes in the normal state, and the water absorption step is executed (S6) when the ball (11) is in the open operation state in which the ball (11) is moved from above the valve hole (9) (S5).

  Along with the execution of the water absorption process, a water absorption timer (not shown) starts measuring the water absorption time (T1 = 30 minutes) (S7), and at the same time, the temperature of the pan bottom (K1) is measured by a temperature sensor (not shown). (S8). In this rice cooking course, brown rice that is difficult to absorb water is cooked, so it is necessary to set the water absorption time longer than that of white rice, and it is set to 30 minutes by experimentally optimizing the water absorption time in advance.

  Eventually, when the pan bottom temperature (K1) reaches 55 degrees (° C.) (S9), the heating amount is controlled by the control means (17) (S10), and the time measurement of the preset water absorption time (T1) is continued. To do. The pan bottom temperature of 55 degrees is a temperature optimized to absorb water in as short a time as possible.

When the water absorption time is 30 minutes (S11), the heating means (4) is heated to the full heating amount (full power heating), and at the same time, the plunger (17) is operated to pull the rod (17a) into the cylinder (17b). With the ball (11) returned to the top of the valve hole (9), the valve hole (9) is closed by the weight of the ball (11), and the pressure in the pan is increased (the pressure in the pan depends on the weight of the ball). (S12) to (S13) (rise heating process).
Thus, by heating with full power and putting the inside of the pan in a pressurized state, more water can penetrate into the rice grains in a short time.

A steam sensor (not shown) measures the steam temperature (K2) when the valve hole (9) is closed by the ball (11) and the heating means (4) is heated at full power ( S14), the temperature is measured until the temperature reaches 75 degrees.
The measurement temperature of 75 degrees by the steam sensor is the temperature of the steam when it is determined that boiling starts under the pressurized condition by the ball (11) at the position where the steam sensor is currently attached.

  When the steam temperature reaches 75 degrees (S15), the heating amount is controlled so that the boiling state is maintained (S16) (boiling maintenance step). In this boiling maintenance step, the plunger (17) is controlled so as not to open, and the pressure valve (14) is maintained in a substantially constant pressure state by the balance between the weight of the ball (11) and the pressure in the pan. Repeat the opening / closing operation in small increments. During this time, sufficient pressure can be applied to absorb moisture in the brown rice. In the boiling state, the boiling temperature is 105 degrees, which is higher than 100 degrees, because the inside of the pan is in a pressurized state.

  Thereafter, the temperature at which the pan bottom temperature (K3) reaches 130 degrees is measured (S17). The pot bottom temperature of 130 ° C. is a temperature at which it is determined that the water in the boiling pot has run out, the forced dry-up is performed, and the dry-up is finished.

  When the pan bottom temperature (K3) reaches 130 degrees (S18), the heating is stopped (S19), the process proceeds to the unevenness process 1, and the timing of the unevenness time (T2 = 4 minutes) is started. Until the time is counted, the pressure valve (14) is not opened by the plunger (17), and the pressure valve (14) is set to the “closed” state (S20). In addition, the optimal time calculated | required experimentally beforehand is used also about the uneven time and the additional cooking time mentioned later.

  When 4 minutes are counted (S21), the pressure valve (14) is opened by the plunger (17) (S22). And it heats by a heating means again, and it transfers to the additional cooking process, and starts time-measurement of reheating time (T3 = 3 minutes) (S23). During reheating, the valve hole (9) is opened and the steam in the pan is released from the valve hole (9) to the atmosphere through the steam port (15) (S23). As a result, the rice can be cooked deliciously by removing it while removing unnecessary moisture on the surface of the grain of rice, and when the lid is opened, the inside of the pan becomes the same as the atmospheric pressure, and the lid can be opened and closed. It becomes easy.

  When the reheating time (T3) finishes timing for 3 minutes (S24), the process proceeds to the unevenness process 2 and starts measuring the unevenness time (T4 = 6 minutes) (S25). When finished (S26), rice cooking is finished (S27), and the process proceeds to the heat retaining step (S28).

Next, the case where “white rice / standard (normal) rice cooking course B” is selected by the selection means (16) (when white rice is normally cooked from white rice) will be described. As shown in the flowcharts of FIGS. 1B, 6 and 7, and the characteristic diagram of FIG. 11, when this course is selected (S29), heating is started by the heating means (4) (S30) and at the same time the plunger The pressure valve (14) is forcibly opened by (17) (S31), and the water absorption process is executed (S32).
The time and temperature settings measured in the following flow are the same as those in the case of “brown rice / standard (normal) rice cooking course B” unless otherwise specified.

The water absorption timer starts measuring the water absorption time (T1 = 15 minutes) (S33), and simultaneously measures the pan bottom temperature (K1) by the temperature sensor (S34).
In the case of white rice, the water absorption is better than that of brown rice, so the water absorption time is set to 15 minutes shorter than that of brown rice.

  When the pan bottom temperature (K1) reaches 55 degrees (S35), the heating amount is controlled to continue the time measurement of the preset water absorption time (T1) (S36).

  When the water absorption time (T1) reaches 15 minutes (S37), the entire heating amount (full power) is heated (S38) (start-up heating process), and at the same time, the plunger (17) is operated to move the rod (17a) to the cylinder. (17b) The ball (11) is pulled into the valve hole (9) by its own weight to close the valve hole (9), and the pressure in the pan is increased (S39).

  The steam temperature (K2) is measured by a steam sensor (not shown) (S40). When it is detected that the steam temperature (K2) has reached 75 degrees (S41), the process proceeds to the boiling maintenance step (S42).

  In the boiling maintaining step, an operation of changing the pressure intermittently by opening the pressure valve (14) by the plunger (17) is performed a plurality of times (S43). That is, the pressure valve (14) is forcibly opened multiple times, and the pressure in the pan is repeatedly reduced by connecting / blocking the pressurized pan and the atmosphere (in this case, the number of times of opening and closing is reduced). It is preferable to increase the stirring effect by using a plurality.) Every time the pressure in the pan drops greatly, a bumping phenomenon occurs, foam is generated in the pan, water and rice are stirred, and the rice grains that were in the center move to the side of the pan, and as a result Sufficient heat will be applied to the whole rice grain.

The pressure fluctuation in the pan at this time is shown in FIG. As soon as the process proceeds to the boiling maintenance step, the first pressure change operation is performed. This is because immediately after entering the boiling maintenance step, the amount of residual water in the pot is large, and the larger the amount of residual water, the easier the rice grains are stirred in the pan and move. Since the amount of residual water decreases as time passes, the rice grains can be stirred more vigorously by forcibly opening the pressure valve (14) with the plunger (17) at the beginning of the boiling maintenance process where the residual water amount is large. it can.
In the second half of the boiling maintenance step, since the amount of residual water in the pan is decreasing, it is difficult for the rice to move, so it is difficult to obtain a large stirring effect even if a bumping phenomenon occurs.

  In this way, the heating state can be averaged by opening and closing the pressure valve (14) several times and stirring the rice grains in the underheated region, so that the top surface of the cooked rice is finally flattened. can do.

  This process is illustrated in FIG. The number of times of opening and closing the pressure valve is set in advance by a program (S44). When the amount of cooking rice is large, the number of times of opening and closing is reduced, and when it is small, the number of times of opening and closing is set large (S45) to (S47). .

  More specifically, when the amount of cooked rice is large, the water level is high and the upper part of the rice is close to the inner lid (7), so if the number of times of opening and closing is increased, the valve hole (9) and the steam port (15 ) And rice grains may pop out. In the present embodiment, in order to prevent this, when the amount of cooked rice is large, the number of opening and closing of the pressure valve (14) is reduced so as to average the rice grains and prevent uneven cooking, and when the amount of cooked rice is small The number of times is increased so that the average and cooking unevenness can be prevented.

When the forced opening operation of the pressure valve (14) and the closing of the pressure valve (14) due to the weight of the ball (11) are repeated a predetermined number of times (S48), then the forced opening operation of the pressure valve (14) is This is not performed (S49), and the pressure valve (14) repeats the opening / closing operation little by little so that a substantially constant pressurized state is maintained by the balance between the weight of the ball (11) and the pressure in the pan.
Further, the heating amount control in the boiling maintenance process is continued (S50), and the boiling maintenance process is continued until the pan bottom temperature (K3) detects 130 degrees (S51).

  When the pan bottom temperature (K3) detects 130 degrees (S52), the heating is stopped (S53) as in the above-mentioned “brown rice / standard (normal) rice cooking course”, and the process goes to the uneven process 1 for the uneven period. Time counting (T2 = 4 minutes) is started (S54), and the opening operation of the pressure valve (14) by the plunger (17) is not performed until the time is counted for 4 minutes.

  When the uneven time is 4 minutes (S55), the process proceeds to the additional cooking process, the force valve 14 is forcibly opened by the plunger (17) (S56), and the reheating time (T3 = 3). Minutes) is started (S57).

  When 3 minutes of the reheating time (T3) is finished (S58), the process proceeds to the unevenness process 2 and the measurement of the unevenness time (T4 = 6 minutes) is started (S59), and the measurement of 6 minutes is completed. Then (S60), rice cooking is finished (S61), and the process proceeds to the heat retaining step (S62).

  In each of the flowcharts of the above-mentioned “brown rice / standard (normal) rice cooking course” and “white rice / standard (normal) rice cooking course”, the pressure valve (14) is forcibly opened after the unevenness process 1 is completed. However, in addition to the purpose of expelling excess moisture when taking out the rice in the pan after cooking has been completed and the process has been shifted to the heat retaining process, the atmosphere enters the pan as the lid (5) is opened. This is to make it easy to open the lid and to prevent the lid from opening suddenly and causing high temperature steam and rice grains to scatter when opening the lid, if the inside of the pan is at high pressure.

Next, the case where “white rice / applied rice cooking course C” is selected by the selection means (16) will be described. When "white rice / application (sushimeshi) rice cooking course C" is selected (S63), it is heated by the heating means (4) as shown in C of FIG. 1, the flowchart of FIGS. 8 and 9, and the characteristic diagram of FIG. At the same time, the pressure valve (14) is opened by the plunger (17) (S65), and the water absorption step is executed (S66).
The time and temperature settings measured in the following flow are the same as those in the case of “brown rice / standard (normal) rice cooking course A” unless otherwise specified.

The water absorption timer starts measuring the water absorption time (T1 = 10 minutes) (S67), and simultaneously measures the temperature of the pan bottom (K1) (S68).
This rice cooking course C is for cooking rice used for pilaf and in this case, it is preferable to suppress the water content in the rice grains. Therefore, the water absorption time is set to 10 minutes, which is shorter than the white rice / standard rice cooking course B.
When the pan bottom temperature (K1) reaches 55 degrees (S69), the heating amount is controlled to continue the time measurement of the preset water absorption time (T1) (S70).

  When the water absorption time (T1) reaches 10 minutes (S71), heating is performed with the total heating amount (full power) (S72), the pressure valve (14) is left open (S73), and the steam temperature (K2) Is detected (S74) (rise heating step).

  When the steam temperature (K2) is detected to be 75 degrees (S75), the process proceeds to the boiling maintenance process and the heating amount control is continued (S76) (boiling maintenance process).

  When the pan bottom temperature (K3) detects 130 degrees (S78), the heating is stopped (S79), the process proceeds to the uneven process 1 and the time of the uneven time (T2 = 4 minutes) is started (S80). During this time, the pressure valve (14) remains open. Therefore, the pressure in the pan of this course is always close to atmospheric pressure.

When the uneven time has passed 4 minutes (S81), the pressure valve (14) remains in the open operation state (S82), the process proceeds to the additional cooking step, and the timing of the reheating time (T3 = 3 minutes) is started (S83). ).
When 3 minutes of reheating time is timed (S84), the process proceeds to the unevenness process 2, and the unevenness time (T4 = 3 minutes) is measured (S85). When measuring the uneven time of 3 minutes (S86), rice cooking is finished (S87), and the process proceeds to the heat retaining step (S88).
In this way, when obtaining rice for sushi and pilaf, it is possible to obtain rice with reduced water absorption that is more than necessary (easy to hold as sushi and with a texture as pilaf).

  Therefore, it is as follows when the operation state of the pressure valve (14) in each rice cooking course is put together. In “Brown Rice / Standard (Normal) Rice Cooking Course A”, during the heating process → closed (the pressure in the pan is pressurized), during the boiling maintenance process → closed (pressurized), during the uneven process → open (omitted) Atmospheric pressure state). In “white rice / standard (normal) rice cooking course B”, during the start-up heating process → closed (pressurized state), during the boiling maintenance process → open, closed (repeated pressurization state, exhaust pressure state), during the unevenness process → Open (substantially at atmospheric pressure). In “white rice / application (sushimeshi) rice cooking course C”, the entire process is changed to open (substantially at atmospheric pressure).

(Modification)
Note that the heating means (4) is not limited to the IH heating method in which heating is performed by eddy current generated by the induction coil, and may be a heating plate with a heater mounted on the bottom of the pan or other heating methods. It is sufficient to use a heating method that enables the above.

  The pressure valve may be of any type as long as it has an opening / closing function that automatically opens when the pressure becomes higher than the set pressure and automatically closes when the pressure becomes lower than the set pressure. In addition, the pressure valve opening mechanism that forcibly opens the pressure valve opening / closing mechanism is a mechanism that works mechanically as long as the valve can be forcibly opened from the closed state. Alternatively, an electromagnetically acting mechanism may be used.

It is a principal part flowchart which shows the rice cooking process by the pressure type rice cooker which is one Example of this invention. It is a figure which shows the partial cross section containing the cover body of the pressure type rice cooker which is one Example of this invention, a pressure valve, and a pressure valve opening mechanism. FIG. 3 is a partial enlarged cross-sectional view of a pressure valve and a pressure valve opening mechanism in FIG. 2. It is a flowchart of the "brown rice and standard (normal) course" of the flowchart shown in FIG. It is a flowchart following the flowchart shown in FIG. It is a flowchart of the "white rice and normal rice cooking course" of the flowchart shown in FIG. It is a flowchart following the flowchart shown in FIG. It is a flowchart of the "white rice and sushi rice cooking course" of the flowchart shown in FIG. It is a flowchart following the flowchart shown in FIG. It is a characteristic figure of "brown rice and normal rice cooking course". It is a characteristic view of "white rice and normal rice cooking course". It is a characteristic view of "white rice and sushimeshi rice cooking course".

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rice cooker body 2 Pan 4 Heating means 5 Cover body 9 Valve hole 10 Valve seat 11 Ball 12 Cover 13 Safety valve 14 Pressure valve 16 Selection means 17 Plunger (pressure valve opening mechanism)
18 Opening / closing mechanism 20 Control means

Claims (6)

A pan into which a predetermined amount of cooked rice containing water and rice is charged, an opening for accommodating the pan, and a rice cooker body having heating means for heating the cooked rice in the pan, the pan and the A lid that closes the opening of the rice cooker body, a pressure valve that communicates or blocks the inside of the pan and the outside air, and a pressure valve that is attached to the pressure valve and forcibly opens the pressure valve from a closed state An opening mechanism, and a control means for controlling the heating amount of the heating means and controlling the opening and closing operation of the pressure valve by the pressure valve opening mechanism, and is in a pressurized state during the boiling maintaining process in a series of rice cooking processes In a pressure rice cooker that cooks rice,
The control means forcibly lowers the pressure in the pan increased in the boiling maintaining step by forcibly opening the pressure valve by the pressure valve opening mechanism to at least 0.1 atm or more. A pressure-type rice cooker controlled to generate a bumping phenomenon in a pot and to stir rice grains.   The control means forcibly opens the pressure valve by the pressure valve opening mechanism during a period when there is sufficient moisture in the initial stage of the boiling maintenance process in which the cooked rice in the pan has reached the boiling temperature due to heating. The pressure rice cooker according to claim 1, wherein   The control means is heated in the fully heated state by the heating means during all the steps of the start-up heating process before shifting to the boiling maintenance process, and does not open the pressure valve by the pressure valve opening mechanism. It controls so that the pressure in the said pan may be raised, The pressure type rice cooker of Claim 2 characterized by the above-mentioned.   The pressure valve is constituted by an automatic opening / closing valve that automatically opens and closes from a closed state to an open state when the pressure in the pan reaches a predetermined value, and the control means is configured after the initial stage of the boiling maintaining step has elapsed. The pressure valve is closed by the pressure valve opening mechanism, and thereafter automatically opened and closed according to the pressure in the pan by the automatic opening and closing valve, so that the pressure in the pan becomes substantially constant. 1. The pressure type rice cooker according to 1.   The pressure type rice cooker according to claim 4, wherein the automatic valve has a valve hole closed with a ball having a predetermined weight.   The control means executes the unevenness process after the completion of the rice cooking that has undergone the boiling maintenance process, and then shifts to the heat retaining process, and the pressure valve is set for a certain period of time at the initial stage of the unevenness process immediately after the completion of the rice cooking. 2. The pressure rice cooker according to claim 1, wherein the pressure valve is opened by the pressure valve opening mechanism and is controlled so that the inside of the pan becomes an atmospheric pressure at the end of the unevenness process.

Images