JP2013013535A - Rice cooker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rice cooker that enhances the taste of an object to be cooked by efficiently injecting superheated steam.SOLUTION: The rice cooker includes: a water tank heating coil 6 for generating steam; a superheated steam temperature detector 18 for detecting the temperature of a superheated steam generator 15 constituted of a case 15b and a rod-shaped heater 15a and supplying superheated steam into a pot 2; and a rice cooking controller 23 for controlling energizing operation of a pot bottom heating unit 8 heating the pot 2 based on the temperature of the pot 2 and energizing operation of the heater 15a based on the detected temperature of the superheated steam temperature detector 18, respectively. Until the superheated steam temperature detector 18 detects a first prescribed temperature T1, the heater 15a is energized at a first prescribed energization rate P1, and subsequently energized at a second prescribed energization rate P2 (P2<P1). Further, heating is adjusted such that, for a first prescribed time S1, heating is performed at the second prescribed temperature T2 (T2>T1), and subsequently, for a second prescribed time S2, and heating is performed at a third prescribed energization rate P3 (P3≤P2<P1) and at the third prescribed temperature T3 (T1<T3≤T2) respectively.

Description

  The present invention relates to a rice cooker, and more particularly, to a rice cooker provided with a superheated steam generator that supplies superheated steam exceeding 100 ° C. from the opening of the pot into the pot.

  Conventionally, various types of rice cookers have been known. For example, Patent Document 1 discloses a rice cooker in which a heater is attached around a steam pipe (steam path) arranged in an internal space of a lid. The conventional rice cooker disclosed by the said patent document 1 can produce | generate the superheated steam exceeding 100 degreeC by heating the steam which passes the inside of a steam pipe by heating a steam pipe with a heater.

  However, in such a conventional rice cooker, there exists a subject that the temperature of superheated steam cannot be made high (for example, 130 degreeC or more). That is, in a configuration in which a heater is disposed around the steam pipe and the steam passing through the steam pipe is heated, the steam and the heater are not in direct contact with each other, so the thermal efficiency of transferring the heat of the heater to the steam is low.

  Moreover, in the said structure, the heat of a heater diffuses to the whole steam pipe. Since the steam pipe has many portions that come into contact with air, the heating efficiency of the steam is deteriorated. For this reason, in order to raise the temperature of superheated steam in the said structure, it is necessary to make the output (work volume) of a heater high, for example. In order to increase the output of the heater, the heater may simply be enlarged. However, electrical appliances such as rice cookers are required to be further downsized. An increase in the size of the heater leads to an increase in the size of the rice cooker.

  To solve this problem, that is, a superheated steam generator capable of further increasing the temperature of the superheated steam and realizing the downsizing of the rice cooker, and a rice cooker equipped with the apparatus, the case and the heat generating part are the case. A rod-shaped heater provided so as to pass through the side wall of the case so as to be disposed in the tip and to be in contact with the case, and the steam taken into the case through a steam intake port There has been proposed one that employs a superheated steam generator that generates superheated steam by heating at a heating portion of a heater and discharges the superheated steam through a superheated steam discharge port (see, for example, Patent Document 2).

Japanese Patent No. 4203995 Japanese Patent No. 3757945

  However, in the structure of the conventional rice cooker as described in the said patent document 2, a 2nd subject newly arises.

  That is, when transferring the heat of the heater to the case, if the temperature rise rate of the heater is large, a temperature difference occurs between the heater and the case. When steam is thrown from the steam generator with a large temperature difference between the heater and the case, the superheated steam heated by the heater is condensed and transferred to the case, and the superheated steam is used to increase the temperature of the case. Steam temperature drops. Thereby, there existed the subject that the temperature rise of a vapor | steam was delayed and thermal efficiency worsened.

  The present invention solves the above-mentioned conventional problem, and when a superheated steam generator is adopted, the heater is heated for a period of time before steaming without increasing the temperature difference between the heater and the case, and the cooked rice is cooked. An object of the present invention is to provide a rice cooker that can improve the taste of food.

  In order to solve the above-described conventional problems, a rice cooker of the present invention includes a pot housed inside a rice cooker body, a pot heating device that heats the pot, a steam generator that generates steam, and a case. A superheated steam generator configured to supply a superheated steam into the pan, comprising a rod-shaped heater, a superheated steam temperature detector for detecting the temperature of the superheated steam generator, a pan temperature detector for detecting the temperature of the pan, A rice cooking control unit that controls the energization operation of the pan heating device based on the detection temperature of the pan temperature detection unit and performs the rice cooking process by controlling the energization operation of the heater based on the detection temperature of the superheated steam temperature detection unit. And the heater is provided so as to penetrate the side wall of the case so that the heat generating part is disposed in the case, and the tip part is in contact with the case. Superheated steam temperature detection Energizing the heater at a first predetermined energization rate P1 until the section detects a first predetermined temperature T1, and then energizing the heater at a second predetermined energization rate P2 (P2 <P1), The temperature is adjusted at the second predetermined temperature T2 (T2> T1) until the first predetermined time S1 has elapsed, and then the second predetermined temperature at the third predetermined energization rate P3 (P3 ≦ P2 <P1). The temperature is adjusted at a third predetermined temperature T3 (T1 <T3 ≦ T2) until a predetermined time S2 elapses. The temperature difference between the heater and the case of the superheated steam generator is not increased. The temperature of the heater can be adjusted for time. This solves the problem that the temperature rise of the steam is delayed and the thermal efficiency is deteriorated, and the superheated steam is supplied into the pan at a stable timing and temperature, so that the taste of the cooked rice can be further improved. I can do it.

  The rice cooker of the present invention can adjust the temperature of the heater for the time until the steam is charged without increasing the temperature difference between the heater and the case of the superheated steam generator. This solves the conventional problem that the temperature rise of the steam is delayed and the thermal efficiency is deteriorated, and the superheated steam can be supplied into the pan at a stable timing and temperature, and the taste of the cooked rice is even better. Can be made.

Sectional drawing of the rice cooker in Embodiment 1 of this invention. Timing chart showing the contents of control when the amount of cooked rice is small Timing chart showing the control content when the amount of rice cooked by the rice cooker is large Timing chart showing the timing in one cycle of the pot bottom heating drive output of the rice cooker and the drive output of the steam heating device

  1st invention consists of the pan accommodated in the inside of a rice cooker main body, the pan heating apparatus which heats the said pan, the steam generator which generate | occur | produces a steam, a case and a rod-shaped heater, and superheated steam in the said pan A superheated steam generator for detecting the temperature of the superheated steam generator, a pan temperature detector for detecting the temperature of the pan, a pan temperature detector for detecting the temperature of the pan, and a detected temperature of the pan temperature detector A rice cooking control unit for controlling the energization operation of the pan heating device and controlling the energization operation of the heater based on the detected temperature of the superheated steam temperature detection unit to perform a rice cooking process, and the heater is a heat generating unit thereof Is disposed in the case so as to penetrate the side wall of the case and have a tip portion in contact with the case. The rice cooking control unit is configured such that the superheated steam temperature detection unit is a first predetermined temperature. Detect temperature T1 Then, the heater is energized at the first predetermined energization rate P1, and then the heater is energized at the second predetermined energization rate P2 (P2 <P1) until the first predetermined time S1 elapses. The temperature is adjusted at a predetermined temperature T2 (T2> T1) of 2, and then the third predetermined time S2 is passed until the second predetermined time S2 elapses at a third predetermined energization rate P3 (P3 ≦ P2 <P1). The temperature is adjusted at a predetermined temperature T3 (T1 <T3 ≦ T2), and the heater can be temperature-controlled during the time until the introduction of steam without increasing the temperature difference between the heater and the case of the superheated steam generator. This solves the problem that the temperature rise of the steam is delayed and the thermal efficiency is deteriorated, and the superheated steam is supplied into the pan at a stable timing and temperature, so that the taste of the cooked rice can be further improved. I can do it.

  In the second invention, in particular, the rice cooking control unit of the first invention performs preheating of the superheated steam generator based on the detected temperature of the superheated steam temperature detecting unit, and controls the temperature of the superheated steam. Therefore, the rice cooker which can select the temperature of the superheated steam suitable for each rice cooking course can be provided.

  In the third aspect of the invention, in particular, the preheating of the superheated steam generator according to the first or second aspect of the invention changes the temperature adjustment temperature according to the amount of cooked rice, and the optimum temperature of the superheated steam according to the amount of cooked rice. A rice cooker that can be used is provided.

  The 4th invention has a plurality of processes and changes the electricity rate especially when the steam is added to the superheated steam generator according to any one of the 1st to 3rd inventions. A rice cooker that can control the temperature of steam more accurately.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a cross-sectional view of the rice cooker in Embodiment 1 of the present invention, FIG. 2 is a timing chart showing control contents when the amount of rice cooked by the rice cooker is small, and FIG. 3 shows the amount of rice cooked by the rice cooker. It is a timing chart which shows the contents of control when there are many.

  In FIG. 1, the rice cooker concerning this Embodiment is accommodated in the substantially bottomed cylindrical rice cooker main body 1 in which the pot accommodating part 1a was formed, and the pot accommodating part 1a, and rice and water are put. A pan 2 is provided. A lid 3 having a hollow structure capable of opening and closing the upper opening 1 d of the rice cooker body 1 is attached to the upper portion of the rice cooker body 1. A substantially disc-shaped inner lid (also referred to as a heating plate) 4 capable of sealing the opening 2a of the pan 2 is detachably attached to the inside of the lid 3 (the side covering the opening 2a of the pan 2).

  The pan storage part 1a of the rice cooker body 1 is composed of an upper frame 1b and a coil base 1c, and the upper frame 1b is a cylindrical shape that is arranged such that a predetermined gap is provided with respect to the side wall of the stored pan 2. A portion 1ba and a flange portion 1bb that protrudes outward from the upper portion of the tubular portion 1ba and fits into the inner peripheral portion of the upper opening 1d of the rice cooker body 1 are provided.

  The flange portion 1bb is formed with a water tank storage portion 1bc for storing the water tank 5. The water tank 5 is a bottomed cylindrical container that holds water for generating steam. A water tank heating coil 6, which is an example of a steam generator that heats the water tank 5 (for example, induction heating), is attached to the outer peripheral surface of the water tank housing 1 bc. In place of the water tank heating coil 6, the water tank 5 may be heated by a heater.

  When the water tank heating coil 6 heats the water tank 5, the water in the water tank 5 boils and steam of about 100 ° C. is generated. In addition, an opening 1bd is provided in a side portion of the water tank storage unit 1bc, and a water tank temperature sensor 7 for measuring the temperature of the water tank 5 is stored in the water tank storage unit 1bc in the opening 1bd. The water tank 5 is disposed so as to be able to contact the side portion.

  The coil base 1c is formed in a bottomed cylindrical shape corresponding to the shape of the lower portion of the pan 2, and the upper portion is attached to the lower end portion of the cylindrical portion 1ba of the upper frame 1b. A pan bottom heating unit 8 which is an example of a pan heating device for heating (induction heating) the pan 2 is attached to the outer peripheral surface of the coil base 1c. The pan bottom heating unit 8 includes an in-bottom heating coil 8a and an out-bottom heating coil 8b. The in-bottom heating coil 8a is disposed so as to face the periphery of the center of the bottom of the pan 2 via the coil base 1c. Outer bottom heating coil 8b is arranged so as to face the corner portion of the bottom of pan 2 via coil base 1c.

  An opening 1ca is provided in the central portion of the bottom of the coil base 1c. In the opening 1ca portion, a pan temperature detection unit 9 for measuring the temperature of the pan 2 is disposed so as to be able to contact the bottom of the pan 2 stored in the pan storage unit 1a. Since the temperature of the pan 2 is substantially the same as the temperature of the cooked rice in the pan 2, the pan temperature detecting unit 9 detects the temperature of the pan 2 to know the temperature of the cooked rice in the pan 2. Can do.

  The lid 3 includes an upper outer member 3 a and a lower outer member 3 b that constitute the outer shell of the lid 3. The lid 3 includes a hinge shaft 3A. The hinge shaft 3A is an opening / closing shaft for the lid 3, and both ends of the hinge shaft 3A are rotatably fixed to the upper frame 1b of the rice cooker body 1. The lid 3 is provided with a through-hole 3c so as to penetrate the vicinity of the center in the thickness direction of the lid 3, and the steam cylinder 10 is detachably attached to the through-hole 3c.

  Steam escape holes 10a and 10b are provided on the upper and bottom walls of the steam cylinder 10 so that excess steam in the pan 2 can be discharged to the outside of the rice cooker. An annular packing 11 is attached around the through hole 3 c on the inner lid 4 side of the lid 3. The packing 11 is provided so that when the inner lid 4 is attached to the lid 3, the packing 11 is in close contact with the periphery of the steam escape hole 4 a provided in the inner lid 4.

  In addition, an inner lid temperature detector 12 that detects the temperature of the inner lid 4 is attached to the lid 3. An inner lid heating coil 13, which is an example of an inner lid heating device for inductively heating the inner lid 4, is attached to the inner surface (inside the lid 3) of the lower outer member 3 b serving as the bottom wall of the lid 3.

  The inner lid 4 is made of a magnetic metal such as stainless steel capable of induction heating. An annular packing 14 is attached to the surface of the outer peripheral portion of the inner lid 4 on the pan 2 side. The packing 14 is provided so as to be in close contact with the flange portion 2b of the pan 2 when the lid 3 is in the closed state.

  In addition, a superheated steam generator 15 for introducing superheated steam exceeding 100 ° C. into the pot 2 is provided inside the lid 3. The mounting structure of the superheated steam generator 15 will be described in detail later.

  The superheated steam generator 15 is configured to be able to generate superheated steam by heating steam at about 100 ° C. generated in the water tank 5. A steam supply pipe 16 and a superheated steam input pipe 17 are connected to the superheated steam generator 15. Further, the superheated steam generator 15 is in contact with a superheated steam temperature detector 18 which is an example of a temperature detector of the superheated steam generator 15.

  The steam supply pipe 16 communicates with the inside of the water tank 5 when the lid 3 is in a closed state, and is provided so as to guide the steam generated in the water tank 5 to the superheated steam generator 15. An annular packing 19 is attached to the end of the steam supply pipe 16 on the water tank 5 side. The packing 19 is provided in close contact with the flange portion 5a of the water tank 5 when the lid 3 is in the closed state.

  The superheated steam input pipe 17 communicates with the inside of the pan 2 through the superheated steam input hole 4b provided in the inner lid 4 when the lid 3 is in the closed state, and the superheated steam generated by the superheated steam generator 15 is stored in the pan 2. It is provided to be put in. An annular packing 20 is attached to the end of the superheated steam input pipe 17 on the pan 2 side. The packing 20 is provided in close contact with the periphery of the superheated steam charging hole 4b of the inner lid 4 when the lid 3 is in the closed state.

  The superheated steam generator 15 includes a cylindrical case 15b and a rod-shaped heater 15a. The heater 15a is disposed coaxially with the central axis A1 of the case 15b in the case 15b. The superheated steam generator 15 heats the steam supplied into the case 15b by the heater 15a to generate superheated steam.

  The lid 3 includes a display unit 21 including a liquid crystal display that displays various information such as a rice cooking course and rice cooking time, and a plurality of rice cooking courses such as a white rice course, a brown rice course, and a white rice (softer) course. The operation part 22 which is an example of the rice cooking course selection part which can select a specific rice cooking course is provided. The operation unit 22 includes a plurality of buttons such as a rice cooking start button so that instructions for starting, canceling, or making a reservation for cooking can be given in addition to selecting a rice cooking course. The user can select a specific rice cooking course with the operation unit 22 while referring to the display content of the display unit 21 and instruct the start of rice cooking.

  A rice cooker control unit 23 is mounted inside the rice cooker body 1. The rice cooking control unit 23 includes a storage unit (not shown) that stores a plurality of rice cooking sequences for cooking rice. Here, the “rice cooking sequence” mainly consists of four steps of preheating, temperature rising, boiling maintenance, and steaming. In performing each step in turn, the energizing time, heating temperature, heating time, heating output, etc. in each step Is a predetermined cooking procedure.

  Each rice cooking sequence corresponds to one of a plurality of rice cooking courses. The rice cooking control unit 23 controls the driving of each unit and each device based on the rice cooking course selected by the operation unit 22 and the temperature detected by the water tank temperature sensor 7, the pan temperature detection unit 9 and the inner lid temperature detection unit 12. And perform the rice cooking process. Further, the rice cooking control unit 23 causes the superheated steam generator 15 to generate superheated steam based on the rice cooking course selected by the operation unit 22 and the detected temperature of the superheated steam temperature detecting unit 18.

  Next, operation | movement of the rice cooker concerning this Embodiment comprised as mentioned above is demonstrated, referring FIGS. 1-3.

  A pan 2 containing white rice and water is placed on the rice cooker body 1, a predetermined amount of water is put into a water tank 5 provided in the rice cooker body 1, a rice cooking course is selected by the operation unit 22, and a rice cooking start switch If a user operates (not shown), a rice cooking process will be started and a preheating process will be started first.

  The preheating process is a process of immersing the rice in water at a temperature lower than the gelatinization temperature so that the rice can be sufficiently gelatinized in the subsequent processes, and allowing the rice to absorb water in advance. In this preheating process, the rice cooking control unit 23 raises the temperature in the pot 2 to a temperature close to the temperature at which rice gelatinization begins (about 60 ° C.), and then maintains the temperature after the temperature increase. The pot heating operation of the pot bottom heating unit 8 is controlled based on the temperature detected by the temperature detector 9. Thereby, water absorption of rice is promoted.

  Moreover, the rice cooking control part 23 drives the water tank heating coil 6 in this preheating process, and preheats the water in the water tank 5. At this time, the steam generated from the water tank 5 is introduced into the pot 2 through the superheated steam generator 15 and the superheated steam input pipe 17 without affecting the inner lid temperature detection unit 12. Due to this configuration, the water tank 5 can be heated sufficiently. If the time preset according to the selected rice cooking course passes from the start of a preheating process, it will transfer to a temperature rising process.

  The temperature raising process is a process in which the pot 2 is heated at a stretch with a strong fire to bring the water in the pot 2 to a boiling state (about 100 ° C.). In this temperature raising step, the rice cooking control unit 23 controls the pot bottom heating unit 8 so as to rapidly heat the pot 2 and bring the water in the pot 2 to a boiling state. When the temperature detected by the pan temperature detector 9 reaches about 100 ° C. by the temperature raising process, the process proceeds to the boiling maintenance process. The time required for this temperature raising step varies depending on the amount of rice cooked (the amount of cooked rice put in the pan 2) and the like. For this reason, the amount of cooked rice can be automatically determined from the time required for the temperature raising step.

  A boiling maintenance process is a process of maintaining the boiling state of the water in the pan 2, gelatinizing rice starch, and raising the gelatinization degree to about 50% to 80%. In this boiling maintenance step, the rice cooking control unit 23 controls the pan bottom heating unit 8 and the inner lid heating coil 13 so as to maintain the boiling state of the water in the pan 2. More specifically, the rice cooking control unit 23 performs duty control that repeats driving (ON) and driving stop (OFF) of the pot bottom heating unit 8 and the inner lid heating coil 13 at regular time intervals to intermittently heat the pot 2. . During this intermittent heating, the temperature of the water tank 5 is also adjusted to maintain the state of the water tank 5 warmed in the preheating process. This boiling maintenance process time also varies depending on the amount of rice cooked and the rice cooking course.

  Further, in the boiling maintenance step, the superheated steam generator 15 starts preheating. The superheated steam generator 15 continues to select the selection until the first predetermined temperature T1 set according to the selected rice cooking course has been reached based on the detected temperature of the superheated steam temperature detection unit 18. Preheating is performed at a first predetermined energization rate P1 set according to the cooked rice cooking course.

  After that, the superheated steam generator 15 has the second predetermined energization rate P2 (P1> P2) set according to the selected rice cooking course until the first predetermined time S1 elapses. The temperature is adjusted at a predetermined temperature T2 (T1 <T2).

  After that, the superheated steam generator 15 has the third predetermined energization rate P3 (P1> P2 ≧ P3) set according to the selected rice cooking course until the second predetermined time S2 elapses. The temperature is adjusted at a predetermined temperature T3 of 3 (T1 <T3 ≦ T2).

  The above T1, T2, T3 and P1, P2, P3 are set by a preset rice cooking course. For example, if it is a plain rice course, T1: 100 ° C, T2: 190 ° C, T3: 180 ° C, P1: 7/16, P2: 3/16, P3: 2/16.

  Moreover, in the brown rice course whose superheated steam temperature is higher than the white rice course, T1: 110 ° C, T2: 190 ° C, T3: 190 ° C, P1: 8/16, P2: 2/16, P3: 2/16 Is set.

  Here, the energization rate represents the energization time per unit time. For example, in the case of energizing for 8 seconds in a 16-second cycle, it is 8/16.

  The first predetermined temperature T1 is a temperature detected by the superheated steam temperature detection unit 18 when the temperature of the heater 15a necessary for supplying superheated steam having a temperature based on the selected course is reached. . However, at this time, the temperature difference between the heater 15a and the case 15b is large (for example, when the superheated steam at 200 ° C. is desired to be emitted, the temperature difference between the heater 15a and the case 15b is about 250 ° C.).

  As shown in FIGS. 2 and 3, the boiling time differs depending on the amount of cooked rice. In order to sufficiently raise the temperature of the heater 15a and the case 15b during the maximum cooking time with the shortest boiling time, it is necessary to raise the temperature to the first predetermined temperature T1 in a short time. The first predetermined energization rate P1 at this time is obtained from the boiling time at the time of maximum rice cooking and the temperature of the heater 15a required for superheated steam generation, and cannot be changed.

  For this reason, after detecting the first predetermined temperature T1, the second predetermined current higher than the first predetermined temperature T1 at the second predetermined power supply rate P2 smaller than the first predetermined power supply rate P1. Temperature control is started at the temperature T2.

  The second predetermined temperature T2 is the temperature of the superheated steam temperature detection unit 18 when the temperature of the case 15b necessary for supplying superheated steam having a temperature based on the selected course is reached (for example, 200 When it is desired to emit superheated steam at 0 ° C., the temperature of the case 15b is preferably 200 ° C. or higher). For this reason, the temperature of the case 15b is increased by keeping the temperature of the case 15b at the second predetermined temperature T2 at the second predetermined energization rate P2 at which the temperature of the heater 15a becomes substantially constant. Thereafter, when the temperature difference between the temperature of the case 15b and the temperature of the heater 15a becomes 100 ° C. or less, the temperature control is continued until a first predetermined time S1 that is experimentally known.

  Thereafter, since the temperature difference is further reduced, the third predetermined energization rate is smaller than the second predetermined energization rate P2 at the third predetermined temperature T3 lower than the second predetermined temperature T2. Adjust the temperature at P3. The reason why the third predetermined temperature T3 is lower than the second predetermined temperature T2 is that the temperature of the entire superheated steam generator 15 has reached the temperature necessary for generating the predetermined superheated steam, and more. This is because it is not necessary to raise the temperature of the superheated steam generator 15.

  In addition, although it was stated that the maximum cooking time was the shortest boiling time, this also varies depending on the rice type, amount of water, cooking rice course, etc., and considering these conditions, the most boiling time in each course The first predetermined energization rate P1 was determined based on a short time.

  By performing these three stages of heater preheating, it is possible to efficiently generate superheated steam in a short time at the target temperature in each course.

  In the boiling maintenance step, water is continuously boiled, and a large amount of steam at about 100 ° C. is generated. The steam passes through the steam escape holes 4a of the inner lid 4 and the steam escape holes 10a and 10b of the steam cylinder 10, and is discharged to the outside of the rice cooker. Thereby, when most of the water in the pot 2 runs out, the temperature of the bottom surface of the pot 2 rises above the boiling point of water. When the pan temperature detection unit 9 detects that the temperature of the bottom surface of the pan 2 has reached the boiling point or higher (for example, 130 ° C.), the panning process is started.

  At this time, even if there is a foreign substance or the like in the pan temperature detection unit 9 and it cannot be detected that the temperature has reached the boiling point or higher, the temperature of the superheated steam generator 15 rises abnormally by performing the three-stage heater preheating. No, the temperature of peripheral parts does not rise abnormally.

  The steaming process is a process of evaporating excess water using residual heat and raising the degree of gelatinization of rice to nearly 100%. In this steaming step, the rice cooking control unit 23 controls the pot bottom heating unit 8 and the inner lid heating coil 13 so as to heat the pot 2 every time the temperature of the pot 2 falls below a certain temperature.

  More specifically, the rice cooking control unit 23 performs duty control that repeats driving (ON) and driving stop (OFF) of the pan bottom heating unit 8 and the inner lid heating coil 13 at regular time intervals in the same manner as the boiling maintenance step. The pan 2 is heated intermittently. Moreover, the rice cooking control part 23 drives the water tank heating coil 6, boils the water in the water tank 5, and generates a vapor | steam.

  Further, the rice cooking control unit 23 drives the superheated steam generator 15 in conjunction with the steam generation of the water tank 5 to prevent the superheated steam generator 15 from being baked. In addition, the superheated steam generator 15 is driven for a long time, and the temperature is raised in a short time so that heat exchange with the steam is performed in a short time, and the superheated steam temperature required for a short time from the start of the steaming process. Are generated (FIGS. 2 and 3).

  Accordingly, it is possible to ensure the steam injection timing necessary for improving the taste, such as adding superheated steam simultaneously with the driving of the pan bottom heating unit 8. By changing the degree of this temperature rise, the steam temperature and steam input timing can be changed to a state necessary for improving the taste required in various rice cooking courses. Then, after reaching the necessary superheated steam temperature, the superheated steam generator 15 is duty controlled so as to maintain the steam temperature.

  By changing the duty control time together with the total number, it is possible to set the steam charging time t2 (t1> t2) at which the surface does not dry even during the maximum cooking (FIG. 3).

  The superheated steam generated by the superheated steam generator 15 is supplied into the pan 2 through the superheated steam charging pipe 17 and the superheated steam charging hole 4 b of the inner lid 4. When the time set in advance according to the amount of cooked rice and the rice cooking course has elapsed since the start of the steaming process, the steaming process is terminated.

  According to the present embodiment, the superheated steam generator 15 is heated while detecting the temperature of the superheated steam generator 15 in the boiling maintenance process, so that it is necessary for steam heating even when the rice is cooked repeatedly or when the room temperature is high or low. Since heating can be stopped at a certain temperature point, the necessary temperature can be supplied at a stable timing without depending on the room temperature or the initial temperature of the superheated steam generator 15.

  Moreover, according to this Embodiment, since the heating of the superheated steam generator 15 is started after a boiling maintenance process, a to-be-cooked item can be heated with the temperature and time according to the amount of rice cooking. When there is much rice cooking amount, the distance from the superheated steam generator 15 to the rice upper surface becomes short. In this case, the temperature when the superheated steam reaches the upper surface of the rice is increased, the amount of heat given to the rice is increased, and the surface layer is dried. As a result, the taste of rice may be reduced. For this reason, the taste improvement of rice can be implement | achieved by changing the temperature of steam | vapor, and steam injection | throwing-in time according to the amount of rice cooking.

  In addition, this invention is not limited to the said embodiment, It can implement in another various aspect. For example, in the above embodiment, the steam supplied to the superheated steam generator 15 is generated by heating the water in the water tank 5, but the present invention is not limited to this. For example, steam generated in the pan 2 during rice cooking may be supplied to the superheated steam generator 15.

  Since the rice cooker concerning this invention can make the taste of a to-be-cooked rice still more favorable according to each rice cooking amount, it is useful for a household rice cooker for business use, a business use, etc.

DESCRIPTION OF SYMBOLS 1 Rice cooker body 1a Pan storage part 2 Pan 3 Lid 3A Hinge shaft 4 Inner lid 5 Water tank 6 Water tank heating coil (steam generator)
7 Water tank temperature sensor 8 Pan bottom heating unit (pan heating device)
9 Pan temperature detection part 10 Steam cylinder 11, 14, 19, 20 Packing 12 Inner cover temperature detection part 13 Inner cover heating coil (inner cover heating device)
DESCRIPTION OF SYMBOLS 15 Superheated steam generator 15a Heater 15b Case 16 Steam supply pipe 17 Superheated steam input pipe 18 Superheated steam temperature detection part 21 Display part 22 Operation part 23 Rice cooking control part

Claims (4)

Overheated steam generation that consists of a pot housed inside the rice cooker body, a pot heating device that heats the pot, a steam generator that generates steam, and a case and a rod-shaped heater that supplies superheated steam into the pot An apparatus, a superheated steam temperature detection unit for detecting the temperature of the superheated steam generation device, a pan temperature detection unit for detecting the temperature of the pan, and energization of the pan heating device based on the detected temperature of the pan temperature detection unit A rice cooking control unit that controls the operation and controls the energization operation of the heater based on the detected temperature of the superheated steam temperature detection unit to perform the rice cooking process, and the heater has a heating part disposed in the case So as to penetrate the side wall of the case and have the tip end in contact with the case, and the rice cooking control unit until the superheated steam temperature detection unit detects the first predetermined temperature T1. First predetermined The heater is energized at the energization rate P1, and then the heater is energized at the second predetermined energization rate P2 (P2 <P1), and the second predetermined temperature T2 until the first predetermined time S1 elapses. The temperature is adjusted at (T2> T1), and then the third predetermined temperature T3 (T1) until the second predetermined time S2 elapses at the third predetermined energization rate P3 (P3 ≦ P2 <P1). <T3 ≦ T2) The rice cooker is characterized by temperature control. The rice cooker according to claim 1, wherein the rice cooking control unit performs preheating of the superheated steam generator based on the detected temperature of the superheated steam temperature detecting unit. The preheating of the superheated steam generator is the rice cooker according to claim 1 or 2, wherein the temperature adjustment temperature is changed according to the amount of rice cooked. The rice cooker according to any one of claims 1 to 3, which has a plurality of steps and changes an energization rate at the time of supplying steam to the superheated steam generator.

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