JP2009100887A - Rice cooker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rice cooker capable of cooking rice to the same deliciousness in both cases of cooking much rice and cooking a little rice. <P>SOLUTION: The rice cooker 1 includes a pot 7, a main body 2 having an opening and heating means 5, a lid body 10, rice cooking amount determining means, storage means, and a controller 24 for executing a prescribed rice cooking process, and the controller 24 performs the rice cooking process including a water absorbing step I, a start heating step II, a boiling step III, and a steaming step IV. In the rice cooker 1, cooking power for each amount of rice cooked to fix the time needed for the start heating step regardless of the amount of rice cooked is stored in storage means, and the controller 24 calls the cooking power corresponding to the amount of rice cooked which is determined by the rice cooking amount determining means from the storage means, supplies the cooking power to the heating means, and executes the start heating process II of elevating the temperature inside the pot to a boiling temperature within the fixed time. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a rice cooker equipped with a microcomputer, and more particularly to a rice cooker having a rice cooking process including a rising heating process in which a heating and heating process from a predetermined water absorption temperature to a boiling temperature is devised.

  A recent rice cooker is equipped with a microcomputer, and a series of rice cooking processes by this microcomputer, that is, a water absorption process for absorbing a predetermined amount of water into a cooked rice, and heating until the cooked cooked rice is boiled The rice is cooked by controlling a rising heating process, a boiling maintaining process for maintaining the cooked rice in a boiling state, a steaming process for steaming the cooked food for a predetermined time, and the like. And among these rice cooking processes, it is known that delicious rice will be cooked when the inside of the pan is heated along a predetermined temperature rise curve in the start-up heating process (see, for example, Patent Document 1 below).

  For example, the rice cooker disclosed in the following Patent Document 1 determines the rice cooking capacity in the pan, sequentially controls the rice cooking process including the start-up heating process and the boiling maintenance process according to this determination amount, and cooks rice. In the jar, this rice cooker is provided with an inner pot temperature detecting means for detecting the temperature of the inner pot bottom, presets a plurality of temperature rise curves at the inner pot bottom as a reference, and the reference inner pot in the rising heating process A temperature control curve is selected according to the rice cooking capacity, and a heating control device is provided for controlling heating based on the temperature detected by the selected pan temperature increase curve and the inner pan temperature detecting means. ing.

According to the rice cooker of this configuration, by selecting and heating the temperature rise curve at the bottom of the inner pot, which is a standard set in advance, according to the amount of rice cooked, the rice and water in the inner pot can be controlled regardless of the amount of rice cooked. Since it is possible to raise the temperature relatively along an appropriate temperature rise curve (ideal rice cooking curve) set by experimental values, delicious rice can be cooked.
Japanese Patent No. 2670720 (FIG. 5, paragraphs [0021] to [0028])

  According to the rice cooker disclosed by the said patent document 1, it can always cook delicious rice irrespective of the amount of rice cooking. However, this rice cooker sets a plurality of appropriate temperature rise curves (ideal rice cooking curves) with rice and water in the inner pot set by experimental values, and the temperature is controlled along this temperature curve. If the conditions do not match the ideal rice cooking curve, the rice cooking along the ideal rice cooking curve will not be achieved. Moreover, since this ideal rice cooking curve is calculated | required by an experimental value, it becomes very troublesome to set and obtain | require various rice cooking conditions, and it is also difficult to specify rice cooking conditions. And in this start-up heating process, if the temperature rise to boiling is raised slowly, uneven rice cooking can be achieved, while on the other hand, if it is raised quickly, it becomes hard rice that feels the core, so temperature control in this start-up heating process is particularly important It has become.

  Then, this invention was made | formed in view of such a situation, and the objective of this invention is providing the rice cooker which can always cook the rice of the same deliciousness irrespective of the amount of rice cooking.

  In order to solve the above-mentioned problems, a rice cooker according to claim 1 of the present invention includes a pan into which a rice to be cooked is charged, an opening in which the pan is accommodated, and a heating means for heating the rice to be cooked in the pan. A rice cooker body having an openable and closable lid that closes the opening of the rice cooker body, a rice cooking amount judgment means for judging the amount of rice cooked in the pan, a storage means for storing various rice cooking menus, and a predetermined rice cooker A controller that executes a process, and the controller controls the heating means according to the rice cooking menu to absorb water in the cooked rice in the pan at a predetermined water absorption temperature and time. A step, a rising heating step for heating and heating the absorbed cooked rice until it boils, a boiling step for maintaining the cooked rice in a boiling state, and a steaming step for steaming the cooked rice after the boiling step, In the rice cooker that performs the rice cooking process including The storage means stores the cooking power for each rice cooking amount so that the time required for the start-up heating step is constant regardless of the rice cooking amount, and the control device, after executing the water absorption step, By calling the cooked power corresponding to the cooked rice amount determined by the cooked rice amount determining means from the storage means, supplying the cooked power to the heating means, and executing the rising heating step, the inside of the pot The temperature is raised to the boiling temperature in a certain time to cook the cooked rice in the pan, and then the boiling step and the steaming step are performed.

  The invention according to claim 2 of the present invention is the rice cooker according to claim 1, wherein the cooked power stored in the storage means is set to a large power when the amount of rice cooking is large, and the amount of rice cooked is When it is low, it is characterized by being set to low power.

  The invention according to claim 3 of the present invention is the rice cooker according to claim 1, wherein in the boiling step, the boiling start time is defined as the boiling start time, and the boiling is maintained after the boiling start time. In addition to the cooking power, the storage means stores boiling start power and boiling maintenance power corresponding to the amount of rice cooked in the boiling start period and the boiling maintenance period. The controller calls the boiling start period power and the boiling maintenance period power corresponding to the rice cooking amount determined by the rice cooking amount determination unit from the storage unit after the water absorption step and the rising heating step. The boiling start period electric power is supplied to the heating means in the boiling start period, and the boiling maintenance period electric power is supplied to the heating means in the boiling maintenance period, respectively, and the boiling process is performed, and then the steaming process is performed. When That.

  The invention according to claim 4 of the present invention is the rice cooker according to claim 3, wherein the boiling start period power and the boiling maintenance period power stored in the storage means are large when the amount of rice cooking is large. When the amount of cooked rice is small, the power is set to be small.

  Moreover, the invention concerning Claim 5 of this invention is the rice cooker concerning Claim 1, The said control apparatus determines the rice cooking amount in the said pan by the said rice cooking amount determination means at the time of the said water absorption process execution. And

  Further, the invention according to claim 6 of the present invention is the rice cooker according to claim 5, wherein the rice cooking amount determination means is the electric power supplied to the heating means that maintains the water absorption temperature within the water absorption time in the water absorption step. It is comprised by the determination means which determines the amount of rice cooking in the said pan according to quantity.

  The invention according to claim 7 of the present invention is the rice cooker according to claim 1, wherein the steaming step includes a re-cooking step of operating the heating means to re-cook the cooked rice, The storage means further stores a follow-up cooking time corresponding to the amount of cooked rice, and the control device executes the water absorption process, the rising heating process and the boiling process, and then uses the cooked rice amount determination means. The additional cooking time corresponding to the determined amount of cooked rice is called from the storage unit, and the steaming step including the additional cooking step of operating the heating unit during the additional cooking time is performed.

  The invention according to claim 8 of the present invention is the rice cooker according to claim 7, wherein the additional cooking time stored in the storage means is set to a long time when the amount of cooked rice is large, and the amount of cooked rice is When the number is small, it is set to a short time.

  By providing the above configuration, the present invention has the following excellent effects. That is, according to invention of Claim 1 and 2, the cooking power for every rice cooking amount is memorize | stored in the memory | storage means of a rice cooker so that the time which a start-up heating process becomes constant irrespective of the rice cooking amount. The controller cooks the cooked power corresponding to the amount of rice cooked to the heating means and executes the start-up heating process to constantly raise the temperature in the pan to the boiling temperature in a certain time, Since cooking is performed, it is possible to provide a rice cooker that can always cook the same delicious rice regardless of the amount of rice cooked.

  Moreover, according to invention of Claim 3 and 4, the memory | storage means of a rice cooker has the boiling start period electric power and boiling maintenance period electric power corresponding to the amount of rice cooking divided into two as a boiling start period and a boiling maintenance period. In addition to controlling the cooking power in the start-up heating process, the control device powers the boiling start period power and boiling maintenance period power corresponding to the amount of cooked rice to the heating means and executes the boiling process. Therefore, it becomes possible to cook even more uniform rice.

  According to the invention of claim 5, the rice cooker control device determines the amount of rice cooked in the pan by the rice amount determination means at the time of the water absorption step, that is, determines the amount of rice cooked in the water absorption step in the first half of the process. This determination result can be reflected in the subsequent process control. As a result, the cooking time corresponding to the determination amount can be increased.

  Moreover, according to invention of Claim 6, a rice cooking amount determination means determines rice cooking amount with the electric energy supplied to the heating means which maintains a water absorption temperature within the water absorption time in a water absorption process. That is, in order to maintain the water absorption temperature, the heating means is repeatedly supplied and stopped, but generally, the water absorption temperature tends to be difficult to increase when the amount of cooked rice is large, and the water absorption temperature increases when the amount of cooked rice is small. Since it tends to be easy, the amount of rice cooked can be judged by the difference in the amount of power supplied to the heating means at this time, so the amount of rice can be measured automatically in the rice cooker, and it is necessary to provide other weighing means Disappears.

  Moreover, according to invention of Claim 7 and 8, by changing the time which the additional cooking process included in a steaming process requires according to the amount of rice cooking, even if it is a case where there is much rice cooking amount, for example, It is possible to sufficiently remove excess water in the pan.

  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.

  With reference to FIGS. 1-4, the structure and control apparatus of the rice cooker which concern on embodiment of this invention are demonstrated. 1 shows a rice cooker according to an embodiment of the present invention, FIG. 1 (a) is a front view, FIG. 1 (b) is an enlarged view of the display portion of FIG. 1 (a), and FIG. FIG. 3 is an enlarged cross-sectional view of the pressure valve opening mechanism of FIG. 2, and FIG. 4 is a block diagram of the control device. .

  As shown in FIG. 1 and FIG. 2, the rice cooker 1 has a pan 7 into which the rice to be cooked is put, an opening in which the pan 7 is accommodated above, and an inner portion in which the pan 7 is heated to prepare the rice to be cooked. A rice cooker main body (hereinafter referred to as a main body) 2 having a heating means 5 for heating, a lid body 10 pivotally supported on one side of the main body 2 to cover the opening and lock in a closed state, and the lid body 10 The pressure valve 13 that is mounted and adjusts the internal pressure in the pan 7, the pressure valve opening mechanism 18 that controls opening and closing of the pressure valve 13, the display operation unit 25 that displays and selects various rice cooking menus, and the selected And a control device 24 that controls the heating means 5 and the pressure valve opening mechanism 18 based on the rice cooking menu to heat the cooked food in the pan 7 to a predetermined temperature and execute a predetermined rice cooking process.

  The main body 2 includes a bottomed box-shaped outer case 3 and an inner case 4 accommodated in the outer case 3, and a gap is formed between the outer case 3 and the inner case 4, and a control device is formed in the gap. A control circuit board and the like (not shown) constituting 24 are arranged. The inner case 4 accommodates a pan 7 made of a deep bottom container. The pan 7 is formed of, for example, a clad material made of aluminum and stainless steel. The inner case 4 is provided with a bottom heater 5b and a side heater 5a on the bottom 4a and side 4b, respectively, and a pan bottom temperature sensor 6 comprising a thermistor for detecting the pan bottom temperature is provided on the bottom 4a. . As the bottom heater 5b, an annular induction coil (hereinafter also simply referred to as an IH coil) is used.

  Further, as shown in FIG. 1, the main body 2 is provided with a display operation unit 25 including a display panel for displaying various rice cooking menus and operation buttons for selecting the rice cooking menus. As shown in FIG. 1, the display operation unit 25 includes a display panel 8 on which various rice cooking selection menus and times are displayed, and a plurality of switch operation buttons 3 a to 3 f on the left and right and below the display panel 8. , 9 are arranged. These operation buttons are a rice cooking / start button 3a for operating the rice cooker, a rice cooking reservation button 3b for making a rice cooking reservation, a cancel / heat keeping button 3c for canceling the setting of rice cooking, a rice selection button 3d for selecting rice to be cooked, A menu selection button 3e for selecting a rice cooking menu, a course button 3f for selecting a course, a cross shift key 9 for selecting and determining a menu displayed on the display panel 8, and the like. These buttons and keys are operation buttons or the like constituting a push button type switch, and each switch (not shown) is operated by pressing this button or key. Among these operation buttons 3a to 3f, the menu selection button 3e is used to display various rice cooking menus on the display panel 8. When this button is pressed, the menu selection button 3e is usually used for softening, softening, porridge, sushi, curry, Various cooking menus such as cooking, cooking, seasonal cooking, and multi-cooking are displayed. The rice selection button 3d is used to select the type of rice, for example, one of white rice, non-washed rice, brown rice, germinated brown rice, and the like. Further, the course button 3f is used to select umami warming, good night warming, multi-cooking, cleaning, and the like. The cross-shift key 9 is used to select a predetermined menu from various menus displayed on the display panel 8. The displayed rice cooking menu, for example, normal, sautéed, soft, porridge, sushi, curry, The four-way key 9 is operated from four seasons cooking and sticking, etc., and the cursor (blinking display) is moved up and down and left and right for selection.

  As shown in FIG. 2, the lid 10 includes an inner lid 11 that closes the opening of the pan 7, an outer lid 12 that closes the entire opening of the main body 2, and the like. One side of the lid body 10 is pivotally supported by the main body 2 by a hinge mechanism, and the other side is locked to a locking portion of the main body 2 by a locking mechanism.

  As shown in FIGS. 2 and 3, the inner lid 11 is provided with a pressure valve 13. The pressure valve 13 is opened by a pressure valve opening mechanism 18. The pressure valve 13 includes a valve seat 15 in which a valve hole 14 having a predetermined diameter is formed, a metal ball 16 placed on the valve seat 15 so as to close the valve hole 14, and movement of the ball 16. It is comprised by the cover 17 which hold | maintains the ball | bowl 16 on the valve seat 15 by restrict | limiting. The pressure valve opening mechanism 18 is composed of a solenoid. A cylinder 19a around which an electromagnetic coil is wound, a plunger 19b for moving the ball 16 in and out of the cylinder 19a by excitation of the electromagnetic coil, and a tip of the plunger 19b. And a spring provided between one end of the cylinder 19a and the operating rod 20.

  The pressure valve opening mechanism 18 is controlled by the control device 24. That is, based on a command from the control device 24, when the electromagnetic coil is excited, the plunger 19b jumps out of the cylinder 19a, the operating rod 20 collides with the ball 16, and pushes the ball 16 in a predetermined direction. By this extrusion, the ball 16 moves on the valve hole 14 and forcibly opens the valve hole 14. Further, in this open state, when the excitation to the electromagnetic coil is stopped, the plunger 19b is drawn into the cylinder 19a by the biasing force of the spring, and the contact between the operating rod 20 and the ball 16 is released by this drawing, and the ball 16 returns to the valve hole 14, and the valve hole 14 is closed by the ball 16.

  The inner lid 11 is provided with a safety valve 22 that releases the pressure in the pan 7 to the outside when the steam pressure in the pan 7 rises to an abnormal pressure that is equal to or higher than a predetermined pressure. A steam temperature sensor 23 is attached to the inner lid 11.

  The outer lid 12 is detachably mounted with a storage tank that stores rice balls that erupt from the pan 7 during rice cooking. A steam port 21 for discharging steam to the outside is formed in this tank.

  Next, with reference to FIG. 4, the structure of the control apparatus 24 for performing a predetermined rice cooking process is demonstrated. As shown in FIG. 4, the control device 24 includes hardware including a circuit board on which a CPU, a ROM, a RAM, and the like are mounted, and includes a rice cooking / start button 3a, a rice cooking reservation button 3b, a cancel / heat keeping button 3c, and rice. A selection button 3d, a menu selection button 3e, a course button 3f, a pan bottom temperature sensor 6, a steam temperature sensor 23, and the like are connected to each other, and signals from these buttons and sensors are input to the CPU. In addition, a timer for measuring a predetermined time, a ROM, and a RAM are connected to the CPU. Further, heaters (IH coils) 5a and 5b, a pressure valve opening mechanism 18, a display (display panel) 8 and the like are connected to the output unit (driver). The ROM stores various rice cooking menus and programs for executing the menus. The IH coil is connected to an inverter circuit, and the IH coil is controlled by this circuit.

  Next, the rice cooking process will be described with reference to FIG. In addition, FIG. 5 is the temperature curve figure which showed the temperature change in the pan 7 in a rice cooking process.

The rice cooking process includes a water absorption process I for absorbing water in the cooked rice in the pan 7, a rising heating process II for heating and heating the absorbed cooked rice until boiling, and the cooked rice in a boiling state. Boiling process III, and steaming process IV in which the cooked rice is steamed for a predetermined time after the boiling process III, and the boiling process III is executed by being divided into a boiling start period III ₁ and a maintenance process III _2. The

In the water absorption process I, the energization of the IH coil is turned on / off at predetermined time intervals, controlled to reach a predetermined water absorption temperature θ, multiplied by a predetermined water absorption time TA, and a predetermined amount of water is applied to the cooked rice. To absorb water. In this water absorption process I, the pressure valve 13 is opened. The water absorption temperature θ is maintained in a predetermined range θ _{1 to} θ ₂ , for example, 59 ° C. to 60 ° C., and the water absorption time TA is set to 15 minutes, for example.

In this water absorption process I, the amount of cooked rice to be cooked in the pan 7 is determined by the pan bottom temperature sensor 6 as a rice cooking amount determination means. This amount of cooked rice is determined based on the energization time to the IH heater necessary to maintain a predetermined water absorption temperature θ (59 ° C. to 60 ° C.) during the water absorption time TA (15 minutes). That is, this energization time is the total value of the energization times t ₁ to t ₄ for the IH coil during the water absorption time TA in FIG.

  When the amount of cooked rice is determined in the water absorption process I, the power of the start-up heating process II and the boiling process III after the water absorption process I and the time of the additional cooking process are determined corresponding to the determination amount.

  With reference to FIG. 6, the relationship between the energization time to an IH coil and the amount of rice cooking is demonstrated. In addition, FIG. 6 is a water absorption temperature curve diagram showing the relationship between the energization time and the amount of cooked rice.

Energization of the IH coil is started with a predetermined amount of cooked rice as a standard, and the inside of the pan 7 is heated from the temperature of normal temperature water to θ ₁ (60 ° C.). When the inside of the pan 7 reaches θ ₁ , energization to the IH coil is temporarily stopped to maintain this temperature. When this energization is stopped, the temperature in the pan 7 decreases to θ ₂ (59 ° C.) after a predetermined time, so this temperature decrease is detected, and energization to the IH coil is started again, and the water absorption temperature is increased. The temperature is increased from θ ₂ to θ ₁ . Thereafter, the water absorption temperature is maintained in the range of θ ₂ to θ ₁ (59 ° C. to 60 ° C. by repeating ON / OFF of energization to the IH coil in the same manner. The temperature curve is as shown by the solid line in FIG.

  On the other hand, when the amount of cooked rice is smaller than this standard, the cooked rice in the pan 7 is likely to warm, so the on / off time of energization to the IH coil is shortened, and the water absorption temperature curve is As shown by the dotted line in FIG. 6, the temperature curve has a smaller amplitude than the standard water absorption temperature curve. On the other hand, when the amount of cooked rice is larger than the standard amount, the cooked rice in the pan 7 becomes difficult to warm, so the on / off time of energization to the IH coil becomes longer, and the water absorption temperature curve is shown in the thin line in FIG. As shown, the temperature curve has a larger amplitude than the standard temperature curve. In FIG. 6, the hatched portion indicates the energization time to the IH coil.

The amount of cooked rice is determined by the total value of the time during which the IH coil is energized. That is, since this total value is proportional to the amount of cooked rice, referring to FIG. 7, when the total energization time to the IH coil is Tt, and when the time Tt is equal to or less than the predetermined time a1, It is determined to be a small amount of cooked rice D1. Moreover, when this time Tt is larger than time a1 and is less than predetermined time a2 (a1 <a2), it determines with medium amount rice cooking amount D2. Furthermore, when the time Tt is larger than the time a2 and not longer than the time a3 (a2 <a3), it is determined that the amount of cooked rice D3 is large. The energization time for 1 cup or less of cooked rice takes about 360 seconds, and for 2 cups of rice, the energization time is in the range of 360 to 430 seconds. This data is stored in storage means in the control device 24. In addition, although the small amount, medium amount, and large amount of rice cooking amounts D1-D3 are classified into arbitrary rice cooking amounts, as the division, rice cooking amount D1 is 1-2 cups, for example, and rice cooking amount D2 is 3-4 cups, Rice cooking amount D3 is set to 5 cups. Although θ _{2 to} θ ₁ are set to 59 ° C. to 60 ° C., this temperature range is arbitrary.

In the next start-up heating step II, the cooked rice in the pan 7 is heated at a certain time TB from the water absorption temperature θ (60 ° C.) to the boiling temperature T ₂ (105 ° C.). This temperature rising heating is executed for a predetermined time TB, for example, 300 seconds (5 minutes) by setting the power PB to the IH coil corresponding to the rice cooking amount determined in the water absorption process I. That is, when the amount of cooked rice is D1, the power is set to PB ₁ , the cooked rice amount D2 is set to PB ₂ , and the cooked rice amount D3 is set to PB ₃ . The relationship between the electric powers PB ₁ , PB ₂ and PB ₃ is set to PB ₁ <PB ₂ <PB ₃ . Thereby, regardless of the amount of cooked rice, the temperature is raised and heated in a certain time TB, so that the transmission of heat to the rice is the same regardless of the amount of cooked rice.

  In this start-up heating process II, energization of the IH coil is turned on and the pressure valve 13 is closed, and the cooked rice after water absorption is heated to the boiling temperature, and the pressure in the pan 7 is atmospheric pressure. To, for example, 1.2 atmospheres.

The boiling process III is divided into a boiling start period III ₁ and a boiling maintenance process III _{2. In} the boiling start period III ₁ , the cooked rice in the pan 7 is heated at a boiling temperature T ₂ (105 ° C.) for a certain time TC. Heated up. This temperature raising heating is executed in a certain time TC, for example, 90 seconds, by setting the power PC to the IH coil corresponding to the rice cooking amount determined in the water absorption process I. That is, when the rice cooking amount is D1, the power is PC ₁ , when the rice cooking amount is D2, the power PC ₂ is set, and when the rice cooking amount is D3, the power PC ₃ is set. The relationship between the powers PC ₁ , PC ₂ , and PC ₃ is set to PC ₁ <PC ₂ <PC ₃ .

Further, the boiling keeping step III _2, maintaining the rice of the pan 7 on the boiling temperature T ₂ (105 ℃), is heated at a predetermined power PD. This heating is executed by setting the power PD ₃ to the IH coil corresponding to the rice cooking amount determined in the water absorption step I. That is, when the amount of rice cooking is D1, electric power PD ₁ is set, when the amount of rice cooking D2 is electric power PD ₂ , and when the amount of rice cooking D3 is electric power PD ₃ is set. The relationship among the powers PD ₁ , PD ₂ and PD ₃ is set to PD ₁ <PD ₂ <PD ₃ .

In the boiling process III, energization of the IH coil and opening / closing of the pressure valve 13 are performed at predetermined time intervals. That is, the opening and closing of the pressure valve 13 is performed once to several times in the initial stage of the boiling process III. As the pressure valve 13 is opened, the pressure in the pan 7 is reduced from 1.2 atm to almost atmospheric pressure. This pressure change causes a so-called bumping phenomenon in which the inside of the pan 7 boils violently. Due to this bumping phenomenon, the rice grains in the pan 7 are agitated. In particular, when the pressure valve 13 is opened and closed at the initial stage of the boiling maintenance process III _2, the rice grains are efficiently stirred because the water in the pan 7 is increased at this stage. On the other hand, energization to the IH coil is turned on / off in synchronization with opening and closing of the pressure valve 13. That is, energization to the IH coil is turned on when the pressure valve 13 is closed, and turned off when the pressure valve 13 is opened. The energization of the IH coil may be asynchronous with the opening / closing of the pressure valve 13. When reaching the latter half of the boiling maintenance step III ₂ , the temperature in the pan 7 rises to 130 ° C. Due to this temperature rise, the water in the boiling pan 7 disappears and forced dry-up occurs. Thereafter, energization to the IH coil is stopped and the process proceeds to the steaming step IV.

This steaming process IV is composed of steaming 1 (first steaming) performed after the boiling maintenance process III _{2 is} completed, additional cooking process performed after the steaming 1 is completed, and steaming 2 (steaming second half) for finishing the steaming. . In the additional cooking process, the inside of the pan 7 is heated and heated to remove unnecessary water.

In this steaming step IV, the additional cooking time Tx is changed depending on the amount of rice cooked. That is, time Tx ₁ is set when the amount of rice cooking is D1, time Tx ₂ is set when the amount of rice cooking D2 and time Tx ₃ is set when the amount of rice cooking D3. The relationship between the times Tx ₁ , Tx ₂ and Tx ₃ is set to Tx ₁ <Tx ₂ <Tx ₃ .

  Next, the rice cooking process will be described with reference to FIGS. 5 and 8 to 12. 8-12 is a flowchart of a rice cooking process. In addition, although various rice cooking menus are displayed on the display panel 8 and can be performed, the case where rice cooking is performed by selecting the white rice / standard rice cooking menu will be described below.

  First, before starting the rice cooking menu, a predetermined amount of water and white rice are put into the pan 7, the pan 7 is accommodated in the inner case 4, the lid 10 is closed and locked to the main body 2. And when not making a rice cooking reservation by step S1, the rice cooking / start button 3a is pressed by step S5, an inverter circuit is started, and electricity supply to an IH coil is started (step S6, S7). In addition, when making a rice cooking reservation, the reservation time is set to a timer and the rice is cooked in the rice cooking reservation mode (steps S2 to S4). Due to the energization of the IH coil in step S7, a high frequency current flows through the IH coil attached to the bottom wall of the inner case 4, an eddy current is generated in the pan 7, the pan 7 generates heat, and the cooked rice is heated. Be started. At the same time, the control device 24 operates the pressure valve opening mechanism 18 to move the ball 16 to open the pressure valve 13 and execute the water absorption process I (steps S9 and S10). In this water absorption process I, a water absorption time TA, for example, 15 minutes is set in the first timer (step S11). When execution of this water absorption process I is started, the first timer starts measuring the water absorption time TA (15 minutes) (steps S12 and S13). During this water absorption time TA, the pan bottom temperature is measured by the pan bottom temperature sensor 6. The energization of the IH coil is turned on until the measured value t reaches a predetermined temperature (θ1) 60 ° C. (actually 59.9 ° C.), and then turned off (steps S14 to S18). After the water absorption time TA has elapsed, the amount of cooked rice in the pan 7 is determined. This determination is made by integrating the energization time to the IH coil during the water absorption process I, so that the amount of cooked rice put in the pan 7 is small (D1), medium (D2), or many (D3). This is done by determining whether or not this is true (steps S19 and S20). The determined amount of cooked rice is temporarily stored in the storage means ROM and RAM.

When the water absorption process I is completed, a rest time is provided to stabilize the inside of the rice cooker 1. In step S21, the pause time TA ′ is set, and the time is counted until the pause time TA ′ reaches 40 seconds (steps S22 and S23). After the pause time TA ′ has elapsed for 40 seconds, the start-up heating process II starts (step S24), and the pressure valve 13 is closed (step S25). Next, the amount of cooked rice determined in step 19 is read from the storage means ROM and RAM (step S27), and the amount of heating (power) PB _n (n) such that the start-up heating time TB corresponding to the amount of cooked rice is 300 seconds. Is set to small = 1, medium = 2, and many = 3 (the same applies hereinafter) according to the determination amount (steps S28 to S30). Then, energization of the IH coil is started (step S31), and the time is counted until the heating time TB reaches 300 seconds (steps S32 and S33).

After completion of the start-up heating process II, the boiling process III is started (step S34). In the boiling process III, first, the boiling start period III ₁ is started (step S35). In the boiling start period III ₁ , the cooked rice in the pan 7 is heated at the boiling temperature (105 ° C.) for a certain time TC, so the boiling time TC is set to 90 seconds (step S 36). Time counting of TC is started (step S38). Meanwhile, the pressure valve 13 is opened (step S37). Also in this boiling start period III ₁ , the amount of cooked rice determined in step S19 is read from the storage means ROM and RAM (step S41), and the heating amount (electric power) PC corresponding to each amount of cooked rice whose boiling time is 90 seconds. _n is set (steps S42 to S44). Then, until the boiling time reaches 90 seconds, the heating amount is controlled by energizing / stopping the IH coil, and the pressure valve 13 is opened and closed to reach the boiling temperature (105 ° C.) (steps S45 to S47). When the boiling start period III ₁ has passed 90 seconds, the boiling maintenance process III ₂ is started (step S48). In the boiling maintenance step III ₂ , the cooked rice in the pan 7 is maintained at the boiling temperature (105 ° C.) and heated with a predetermined power PD. Therefore, even boiling maintained Step III _2, similarly, heat corresponding to the storage unit ROM, reads from the RAM (step S50) each rice amount such that the predetermined boiling maintenance time TD _n the determined cooking amount in step S19 the amount (power) setting the PD _n (step S51 to S53). Then, until the boiling maintenance time TD _n, controls the amount of heating by energization / stop IH coil, set boiled maintained timed boiling maintenance time TD _x to time become TD _n boiling maintaining time TD _x boiling the pressure valve 13 When the maintenance time becomes TD _n is in the open state and starts the steaming step IV (step S54~S58).

In the initial stage of the boiling process III, energization of the IH coil and opening / closing of the pressure valve 13 are performed at predetermined time intervals. With the opening of the pressure valve 13, the pressure in the pan 7 decreases at a stretch from 1.2 atmospheres to approximately atmospheric pressure. This pressure change causes a so-called bumping phenomenon in which the inside of the pan 7 boils violently. Due to this bumping phenomenon, the rice grains in the pan 7 are agitated. In particular, when the pressure valve 13 is opened and closed at the initial stage of the boiling process III, the rice grains are efficiently stirred because the water in the pan 7 is increased at this stage. On the other hand, energization to the IH coil is turned on / off in synchronization with opening and closing of the pressure valve 13. That is, energization to the IH coil is turned on when the pressure valve 13 is closed, and turned off when the pressure valve 13 is opened. The energization of the IH coil may be asynchronous with the opening / closing of the pressure valve 13. When reaching the second half of the boiling maintenance step III ₂ , the temperature in the pan 7 rises to 130 ° C. Due to this temperature rise, the water in the boiling pan 7 disappears and forced dry-up occurs.

Cooking this steaming step IV is, steaming 1 begins the process (step S59), and then performs the reheating (step S60), where, since the reheating time Tx _n is changed by the rice amount, determined in step S19 the amount storage means ROM, reads from the RAM (step S61) to follow in accordance with the respective rice amount cooking setting a time Tx _n (step S63~S65). Then, the reheating is started (step S66) reheating performed 'clocking and TE' time TE until a set Tx _n (step S67～S68), the process proceeds to subsequent steaming 2 steps (step S69). Then, when the steaming process IV is completed, the process proceeds to a heat retaining process (step S70). All the cooking process is completed.

  Although this invention demonstrated with the pressure type rice cooker, it is not limited to this pressure type rice cooker, A normal pressure type rice cooker may be sufficient. Further, the heating means is not limited to the IH heating method in which heating is performed by eddy current generated by the induction coil, and a heating plate in which a heater is mounted on the bottom of the pan or other heating methods may be used.

FIG. 1: shows the rice cooker which concerns on embodiment of this invention, FIG. 1 (a) is a front view, FIG.1 (b) is an enlarged view of the display part of Fig.1 (a). FIG. 2 is a longitudinal sectional view of the rice cooker of FIG. FIG. 3 is an enlarged cross-sectional view of the pressure valve opening mechanism of FIG. FIG. 4 is a block diagram of the control device. FIG. 5 is a temperature curve diagram showing changes in temperature and pressure in the pan in the rice cooking process. FIG. 6 is a water absorption temperature curve diagram showing the relationship between the energization time and the amount of cooked rice. FIG. 7 is a diagram showing the relationship between the time and power of each process defined by each determination amount. FIG. 8 is a rice cooking flowchart. FIG. 9 is a rice cooking flowchart following FIG. FIG. 10 is a rice cooking flowchart following FIG. FIG. 11 is a rice cooking flowchart following FIG. FIG. 12 is a rice cooking flowchart following FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rice cooker 2 Rice cooker main body 3 External case 4 Internal case 5 Heating means 6 Pan bottom temperature sensor 7 Pan 10 Lid body 11 Inner lid 12 Outer lid 13 Pressure valve 14 Valve hole 15 Valve seat 16 Ball 17 Cover 18 Pressure valve release mechanism 19a Cylinder 19b Plunger 20 Actuation rod 22 Safety valve 21 Steam port 23 Steam temperature sensor 24 Controller 25 Display operation unit

Claims (8)

A rice cooker body having a pan into which the cooked rice is put, an opening in which the pan is accommodated, and a heating means for heating the cooked rice in the pan, and an openable / closable lid that closes the opening of the cooker body Body, rice cooking amount determination means for determining the amount of rice cooking in the pan, storage means for storing various rice cooking menus, and a control device for executing a predetermined rice cooking process,
By the control device, according to the rice cooking menu, the heating means is controlled to absorb the water in the cooked rice in the pan at a predetermined water absorption temperature and water absorption time, and the absorbed cooked rice In a rice cooker that performs a rice cooking process that includes a rising heating process that heats up until boiling, a boiling process that maintains the cooked rice in a boiling state, and a steaming process that steams the cooked food after the boiling process ,
In the storage means, the cooking power for each cooked rice amount is stored so that the time required for the start-up heating step is constant regardless of the cooked rice amount,
The control device, after executing the water absorption step, calls the cooked power corresponding to the amount of cooked rice determined by the cooked rice amount determining unit from the storage unit, and feeds the cooked power to the heating unit to A rice cooker characterized in that the boiling step and the steaming step are sequentially executed after the temperature in the pan is raised to a boiling temperature in a certain time by executing a rising heating step.   The cooked power stored in the storage means is set to a large power when the amount of cooking rice is large, and is set to a small amount of power when the amount of rice cooking is small. vessel. The boiling process is divided into two as a boiling start period, and a state of maintaining boiling after the boiling start period as a boiling maintenance period.
The storage means further stores boiling start period power and boiling maintenance period power corresponding to the amount of cooked rice in the boiling start period and the boiling maintenance period,
The controller calls the boiling start period electric power and the boiling maintenance period electric power corresponding to the rice cooking amount determined by the rice cooking amount determination unit from the storage unit after the water absorption step and the rising heating step, and the boiling The boiling start period electric power is supplied to the heating means in the start period, and the boiling maintenance period electric power is supplied to the heating means in the boiling maintenance period, respectively, and the boiling step is performed thereafter. Item 9. A rice cooker according to item 1.   The boiling start period power and the boiling maintenance period power stored in the storage means are set to a large power when the amount of cooking rice is large, and set to a small power when the amount of cooking rice is small. The rice cooker of Claim 3.   The said control apparatus determines the rice cooking amount in the said pan by the said rice cooking amount determination means at the time of the said water absorption process, The rice cooker of Claim 1 characterized by the above-mentioned.   The rice cooking amount determination means is constituted by determination means for determining the amount of rice cooking in the pan by the amount of electric power supplied to the heating means that maintains the water absorption temperature within the water absorption time in the water absorption step. The rice cooker according to claim 5. The steaming step includes a re-cooking step of operating the heating means to re-cook the cooked rice,
The storage means further stores a cooking time corresponding to the amount of cooked rice,
The control device, after executing the water absorption step, the rising heating step, and the boiling step, calls the additional cooking time corresponding to the rice cooking amount determined by the rice cooking amount determination unit from the storage unit, and The rice cooker according to claim 1, wherein the steaming step including the additional cooking step of operating the heating means during a cooking time is performed.   The cooked rice time stored in the storage means is set to a long time when the amount of cooked rice is large, and set to a short time when the amount of cooked rice is small. vessel.

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