JP2016174707A - Rice cooker, and control method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rice cooker that can improve energy saving performance by reducing a preheating time of a first heating part.SOLUTION: A pot 2 includes an opening 2a at one side, and a bottom face 2b at the other side. A lid body 3 is attached to a rice cooker body 1 in a freely openable/closable manner. An inner lid 5 is attached to the lid body 3. The inner lid 5 covers the opening 2a when the lid body 3 is in a closed state with respect to the rice cooker body 1. A water tank 6 is attached to the rice cooker body 1 or to the lid body 3. A steam passage 16 is attached to the lid body 3. The steam passage 16 includes a discharge port 16a, one end of which is connected to the water tank 6, and the other end of which is open toward the opening 2a. The water accumulated in the water tank 6 changes its state by being heated, and becomes steam. The steam passage 16 discharges steam whose state has changed from the discharge port 16a toward the opening 2a. A steam passage heating part 17 which is a first heating part heats the steam passage 16. An inner lid heating part 15 which is a second heating part heats the inner lid 5.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a rice cooker and a method for controlling the rice cooker, and more particularly to a rice cooker having a steam generator.

  Conventionally, in order to improve the taste of rice, this type of rice cooker has been proposed as follows. That is, the conventional rice cooker generates superheated steam with a superheated steam generator (corresponding to the “first heating unit” of the present invention) during rice cooking, and supplies the generated superheated steam to the pan. (For example, refer to Patent Document 1).

  This will be described in detail with reference to the drawings. In the following description, the upper side in the figure is the upper part of the rice cooker.

  As shown in FIG. 6, the conventional rice cooker 200 includes a rice cooker body 201, a pan 202, a lid 203, and a water tank 206. The pan 202 is stored in the rice cooker body 201. Rice and water are put into the pot 202 when cooking rice. A water tank heating coil 207 is attached to the water tank 206. The water tank heating coil 207 heats the water stored in the water tank 206.

  The lid 203 is attached to the upper part of the rice cooker body 201. The lid 203 is configured to be openable and closable with respect to the rice cooker body 201. When the lid 203 is in a closed state with respect to the rice cooker main body 201, the lid 203 covers the opening 201a included in the rice cooker main body 201. An overheated steam generator 204 is attached inside the lid 203. The superheated steam generator 204 discharges superheated steam exceeding 100 ° C. toward the pan 202. The lid 203 has an inner lid heating unit 215 that heats the pan 202 from above.

  The rice cooker 200 which comprises the above structure performs the following operation | movement.

  That is, in the rice cooking steaming process, the rice cooker 200 boiles the water in the water tank 206. The boiled water is sent into the superheated steam generator 204. The superheated steam generator 204 further heats the boiled water to generate superheated steam. The generated superheated steam is jetted into the pot 202.

Japanese Patent Application Laid-Open No. 2014-000284

  However, it has been found that the above-described conventional rice cooker has room for the following improvement. That is, when the conventional rice cooker operates the superheated steam generator, further shortening of the preheating time is desired. Moreover, the conventional rice cooker is desired to improve energy saving performance by reducing power consumption.

Specifically, the conventional rice cooker uses an electric resistance heater as a heat source of the superheated steam generator. In the electric resistance heater, the red hot part emits heat and conducts heat to the surrounding heated object. That is, the electric resistance heater has a low heat transfer rate because it releases heat in the direction in which the object to be heated does not exist. Therefore, the heat generated by the electric resistance heater may not be efficiently transferred to the steam.

  In order to compensate for the drawbacks of such an electric resistance heater, the conventional rice cooker extends the preheating time of the superheated steam generator. By extending the preheating time of the superheated steam generator, the low heat transfer rate of the electric resistance heater is compensated. As a result, the steam is superheated inside the superheated steam generator.

  However, since the conventional rice cooker has a long preheating time, the rice cooking process becomes long and the energy saving performance may be impaired. For example, in the conventional rice cooker, in order to shorten a rice cooking process, it is possible to shorten the preheating time with respect to a superheated steam generator. In the preheating process, the superheated steam generator requires a certain amount of electric power. Therefore, in order to shorten the preheating time, the superheated steam generator needs to increase the output of the electric resistance heater. That is, if a high-output electric resistance heater is used, the amount of heat that can be given to the steam can be increased within a unit time, so that the preheating time can be shortened.

  By the way, in order to increase the output of the electric resistance heater, it is necessary to enlarge the electric resistance heater. If the electric resistance heater becomes larger, the rice cooker also becomes larger. Recently, home appliances such as rice cookers are required to be further downsized. Therefore, the appealing power as a product of a rice cooker having a large size is reduced.

  This invention solves such a conventional subject, and it aims at providing the rice cooker which improves energy-saving property while shortening the preheating time of a 1st heating part.

  In order to achieve the above object, a rice cooker according to the present invention includes a rice cooker body, a pan, a lid, an inner lid, a liquid tank, a steam passage, a first heating unit, and a second heating. A section.

  The pot is stored in the rice cooker body. The pan includes an opening on one side and a bottom surface on the other.

  The lid is attached to the rice cooker body so as to be freely opened and closed. The inner lid is attached to the lid. The inner lid covers the opening when the lid is closed with respect to the rice cooker body.

  The liquid tank is attached to the rice cooker body or the lid. The liquid tank stores liquid.

  The steam passage is attached to the lid. The steam passage includes a discharge port having one end connected to the liquid tank and the other end opening toward the opening when the lid is closed with respect to the rice cooker body. The liquid stored in the liquid tank changes its state by being heated and becomes vapor. The steam passage discharges the steam whose state has changed from the discharge port toward the opening.

  The first heating unit is attached to the steam passage. The first heating unit heats the steam passage. The second heating unit is attached to the lid. The second heating unit heats the inner lid.

  With this configuration, the second heating unit heats the inner lid in the first step from the start of cooking until the object to be cooked that has been put inside the pan boils. In the second step until the cooking is completed after the object to be cooked put in the pot is boiled, the first heating unit heats the steam passage, and the second heating unit covers the inner lid. Heat.

That is, in the first step, the energy supplied to the second heating unit is transmitted to the steam passage in addition to the inner lid. Therefore, the second heating unit can preheat the steam passage.

  In the present invention, the second heating unit can preheat the steam passage before the second step in which the first heating unit heats the steam passage is started. Therefore, the preheating time of the said generator can be shortened. In the present invention, since the steam passage is warmed before the second step starts, the energy required for the first heating unit to raise the steam passage to the target temperature can be reduced.

The disassembled perspective view of the rice cooker in embodiment of this invention Sectional drawing which shows the outline | summary of the rice cooker in embodiment of this invention. Explanatory drawing explaining the outline | summary of the cover body used for the rice cooker in embodiment of this invention. The disassembled perspective view explaining the 1st heating part used for the rice cooker in embodiment of this invention The figure which shows the timing chart of the cooking process of the rice cooker in embodiment of this invention. Sectional drawing which shows the conventional rice cooker

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

  The following embodiments are examples embodying the present invention, and do not limit the technical scope of the present invention. Moreover, in the following description, the same code | symbol is attached | subjected to the same component and description is used.

(Embodiment)
FIG. 1 is an exploded perspective view of a rice cooker according to an embodiment of the present invention. Drawing 2 is a sectional view showing an outline of a rice cooker in an embodiment of the invention. Drawing 3 is an explanatory view explaining an outline of a lid used for a rice cooker in an embodiment of the invention. FIG. 4 is an exploded perspective view illustrating a first heating unit used in the rice cooker according to the embodiment of the present invention. FIG. 5 is a diagram showing a timing chart of the cooking process of the rice cooker in the embodiment of the present invention.

  In addition, let the left side be the upper part of a rice cooker in FIG. 2 mentioned later.

  As shown in FIGS. 1 and 2, the rice cooker 100 in the embodiment of the present invention includes a rice cooker body 1, a pan 2, a lid 3, an inner lid 5, and a water tank 6 that is a liquid tank. , A steam passage 16, a steam passage heating unit 17 that is a first heating unit, and an inner lid heating unit 15 that is a second heating unit.

  The pan 2 is stored in the rice cooker body 1. The pan 2 includes an opening 2a on one side and a bottom surface 2b on the other side.

  The lid 3 is attached to the rice cooker body 1 so as to be freely opened and closed. The inner lid 5 is attached to the lid body 3. The inner lid 5 covers the opening 2 a when the lid 3 is in a closed state with respect to the rice cooker body 1.

A water tank 6 that is a liquid tank is attached to the rice cooker body 1 or the lid 3. In this Embodiment, it attaches to the rice cooker main body 1. FIG. The water tank 6 that is a liquid tank stores water that is a liquid.

  The steam passage 16 is attached to the lid 3. When the lid 3 is in a closed state with respect to the rice cooker body 1, the steam passage 16 is connected to the water tank 6 which is a liquid tank at one end, and the discharge port 16a whose other end opens toward the opening 2a. including. The water tank 6 that is a liquid tank stores water that is a liquid. Water changes its state by being heated, and becomes water vapor which is steam. The steam passage 16 discharges steam, which is steam whose state has changed, from the discharge port 16a toward the opening 2a.

  A steam passage heating unit 17 that is a first heating unit is attached to the steam passage 16. The steam passage heating unit 17 that is the first heating unit heats the steam passage 16. The inner lid heating unit 15 that is the second heating unit is attached to the lid 3. The inner lid heating unit 15 that is the second heating unit heats the inner lid 5. The inner lid heating unit 15 may heat the inner lid 5 directly or indirectly. In the following embodiment, the inner lid heating unit 15 uses an induction coil 15a. The induction coil 15a indirectly heats the inner lid 5.

  With this configuration, in the first step from the start of cooking until the object to be cooked put in the pot 2 boils, the inner lid heating unit 15 that is the second heating unit heats the inner lid 5. In the second step until cooking is completed after the object to be cooked put in the pot 2 is boiled, the steam passage heating unit 17 that is the first heating unit heats the steam passage 16, The inner lid heating unit 15 that is the second heating unit heats the inner lid 5.

  That is, in the first step, the energy supplied to the inner lid heating unit 15 that is the second heating unit is transmitted to the steam passage 16 in addition to the inner lid 5. Therefore, the inner lid heating unit 15 as the second heating unit can preheat the steam passage 16.

  As a result, the rice cooker 100 according to the present embodiment has an inner lid that is a second heating unit before the second step in which the steam passage heating unit 17 that is the first heating unit heats the steam passage 16 starts. The heating unit 15 can preheat the steam passage 16. Therefore, the rice cooker 100 in this Embodiment can shorten the preheating time which the steam channel | path heating part 17 performs. Moreover, since the steam path 16 is warmed before the 2nd process starts the rice cooker 100 in embodiment of this invention, the steam path heating part 17 which is a 1st heating part is the steam path 16. The temperature at which the temperature rises can be reduced. Moreover, in the second step, the steam passage 16 is heated from the steam passage heating unit 17 that is the first heating unit and the inner lid heating unit 15 that is the second heating unit. Therefore, the energy required for the steam passage heating unit 17 to raise the steam passage 16 to the target temperature can be reduced.

  That is, the rice cooker 100 in the embodiment of the present invention can shorten the cooking time and improve the energy saving performance.

  In particular, the following forms exhibit significant effects.

  That is, in the rice cooker 100 in the present embodiment, the inner lid heating unit 15 that is the second heating unit is located between the inner lid 5 and the steam passage 16. In particular, as shown in FIG. 2, the inner lid heating unit 15 is located below the steam passage 16.

  Moreover, as shown in FIG. 2, FIG. 3, in the rice cooker 100 in this Embodiment, the steam path 16 is between the part 16b from which the steam path 16 connects with the water tank 6 which is a liquid tank, and the discharge port 16a. Thus, a body portion 16c extending along the surface formed by the inner lid 5 is included.

  Moreover, in the rice cooker 100 in this Embodiment, the inner cover heating part 15 which is a 2nd heating part is between the part 16b from which the steam path 16 connects with the water tank 6 which is a liquid tank to the discharge port 16a. , Located across the steam passage 16.

  Moreover, in the rice cooker 100 in the present embodiment, the steam passage heating unit 17 that is the first heating unit is between the portion 16b where the steam passage 16 is connected to the water tank 6 that is a liquid tank and the discharge port 16a. , Attached to the steam passage 16.

  If it is set as the above structure, the energy which the inner cover heating part 15 emits will be transmitted to the vapor | steam channel | path 16 directly or indirectly. Furthermore, since the heat generated in the inner lid 5 moves upward, it is transmitted to the steam passage 16 located above the inner lid 5. Therefore, the energy generated by the inner lid heating unit 15 is efficiently transmitted to the steam passage 16 and preheating is promoted.

  Moreover, in the rice cooker 100 in the present embodiment, the steam passage heating unit 17 that is the first heating unit is between the portion 16b where the steam passage 16 is connected to the water tank 6 that is a liquid tank and the discharge port 16a. , Attached to the steam passage 16. Furthermore, the inner lid heating unit 15 as the second heating unit is located at a position different from the portion to which the steam passage heating unit 17 as the first heating unit is attached and intersects with the steam passage 16.

  If it is set as the above structure, the inner cover heating part 15 can heat about the principal part of the steam path 16 which the steam path heating part 17 cannot heat directly. Therefore, since the steam passage 16 is heated over a wider range, the steam can be overheated more efficiently.

  Moreover, as shown in FIG. 4, in the rice cooker in this Embodiment, the vapor | steam passage heating part 17 which is a 1st heating part has the induction coil 30 and the heat exchanger 31 containing a nonmagnetic metal. .

  If it is set as the above structure, the vapor | steam channel | path heating part 17 can heat the vapor | steam channel | path 16 uniformly via the heat exchanger 31. FIG.

  In addition, as shown in FIG. 2, rice cooker 100 in the present embodiment further includes a control unit 41. The control unit 41 switches between the first process and the second process. In the first step, the inner lid heating unit 15 as the second heating unit heats the inner lid 5. In the second step, the steam passage heating unit 17 that is the first heating unit heats the steam passage 16, and the inner lid heating unit 15 that is the second heating unit heats the inner lid 5.

  Especially rice cooker 100 in this embodiment provided with the above-mentioned composition performs the following operations. That is, in the first step, the inner lid heating unit 15 that is the second heating unit preheats the steam passage 16. In the second step, the inner lid heating unit 15 that is the second heating unit heats the steam passage 16 in an auxiliary manner.

  If the above operation | movement is performed, in the 1st process, the energy which the inner cover heating part 15 which is a 2nd heating part discharge | releases can be utilized without waste.

  Further, in the second step, the steam passage heating unit 17 as the first heating unit has the following advantages when heating the steam passage 16 to a target temperature.

  That is, the steam passage 16 is preheated by the inner lid heating unit 15 and raised to a corresponding temperature. Therefore, the temperature at which the steam passage heating unit 17 pulls up the steam passage 16 decreases.

  Furthermore, in the second step, the inner lid heating unit 15 continues to heat the inner lid 5. Therefore, the inner lid heating unit 15 continues to give energy to the steam passage 16 together with the steam passage heating unit 17. In other words, the steam passage heating unit 17 can directly reduce the energy for heating the steam passage 16. Furthermore, in the first step, since the steam passage 16 is preheated, the rice cooker 100 in the present embodiment can quickly extract superheated steam from the steam passage 16.

  As a result, the rice cooker in this Embodiment can reduce the energy consumed while heating efficiency improves.

  Furthermore, it demonstrates in detail.

  As shown in FIGS. 1 and 2, the rice cooker 100 includes a rice cooker body 1 and a pan 2. As for the rice cooker main body 1, the pot accommodating part 1a is formed in the inside. The rice cooker body 1 is substantially cylindrical and has a bottom surface 1b. The pot 2 contains a cooking object including rice and water.

  The rice cooker 100 has a lid 3 attached to the top of the rice cooker body 1. The lid 3 can be opened and closed with the hinge shaft 3a as the center of rotation. The lid 3 has an upper outer shell 3b and a lower outer shell 3c. The lid 3 is hollow. The lid 3 has an inner lid 5 attached to the rice cooker body 1 side of the lower outer shell 3c. In the state where the lid 3 is closed to the rice cooker body 1 shown in FIG. 2, the inner lid 5 is in close contact with the opening 2 a of the pan 2. As shown in FIG. 1, in the present embodiment, the inner lid 5 has a substantially disk shape. The inner lid 5 is detachable from the lid 3.

  The pan storage part 1a formed inside the rice cooker body 1 includes an upper frame 1c and a coil base 1d. The upper frame 1c has a cylindrical portion 1ca and a flange portion 1cb. The cylindrical portion 1ca is positioned with a predetermined gap between the cylindrical portion 1ca and the side wall 2c of the stored pot 2. The flange part 1cb is attached to the upper part of the cylindrical part 1ca. The flange portion 1 cb protrudes from the tubular portion 1 ca toward the outside of the rice cooker body 1. The flange portion 1cb is fitted with an inner peripheral portion 1e located at the upper portion of the rice cooker body 1. Further, in the flange portion 1cb shown on the right side in FIG. 2, a water tank housing portion 1cc for housing the water tank 6 is formed.

  The water tank 6 is a cylindrical container having a bottom surface. The water put in the water tank 6 generates steam. A water tank heating coil 7 is attached to the outer periphery of the water tank housing 1 cc. The water tank heating coil 7 is an example of a water tank heating device, and heats the water tank 6 by induction. The water tank heating device can use an electric resistance heater or the like instead of the water tank heating coil 7. When the water tank heating coil 7 heats the water tank 6, the water in the water tank 6 boils. When the water in the water tank boils, steam of about 100 ° C. is generated. An opening is formed on the side surface of the water tank housing 1cc. A water tank temperature sensor 6a is attached to this opening. The water tank temperature sensor 6 a is attached in contact with the side surface of the water tank 6. The water tank temperature sensor 6 a measures the temperature of the water tank 6.

The coil base 1 d has a cylindrical shape having a bottom surface so as to correspond to the shape of the lower portion of the pan 2. The upper part of the coil base 1d is attached to the lower end of the cylindrical part 1ca which the upper frame 1c has. A pan bottom heating unit 8 for heating the pan 2 is attached to the outer peripheral surface of the coil base 1d. In the present embodiment, a mode in which the pan 2 is induction-heated is shown. The pan bottom heating unit 8 includes a bottom surface heating coil 8a and a side surface heating coil 8b. The bottom surface heating coil 8a induction-heats the bottom surface 2b included in the pan 2 via the coil base 1d. The bottom surface heating coil 8a is disposed so as to face the bottom surface 2b with the center portion of the bottom surface 2b included in the pan 2 as the center. A plurality of ferrites 9 are attached below the bottom surface heating coil 8a. The plurality of ferrites 9 induce magnetic flux generated from the bottom surface heating coil 8 a into the plurality of ferrites 9. The plurality of ferrites 9 reduce the leakage of magnetic flux generated from the bottom heating coil 8a from the rice cooker 100.

  The side surface heating coil 8b induction-heats the corner | angular part 2d of the bottom face 2b which the pan 2 contains via the coil base 1d. Side heating coil 8b is arranged to face corner 2d included in pan 2.

  The coil base 1d is formed with an opening in the central portion at the bottom. A pan temperature sensor 10 is attached to this opening. The pan temperature sensor 10 is attached in contact with the bottom surface 2 b of the pan 2. The pan temperature sensor 10 measures the temperature of the pan 2. Note that the measured temperature of the pan 2 is substantially the same as the temperature of the object to be cooked cooked in the pan 2. Therefore, it can be understood that the temperature of the pan 2 measured by the pan temperature sensor 10 is the temperature of the object to be cooked cooked in the pan 2.

  The lid 3 is configured by an upper outer shell 3b and a lower outer shell 3c. The lid 3 has a hinge shaft 3a. The hinge shaft 3 a is an opening / closing shaft for the lid 3. Both ends of the hinge shaft 3a are held by an upper frame 1c included in the rice cooker body 1. The lid 3 is rotatably held around the hinge shaft 3a as a rotation center.

  A through hole 3 d is formed in the lid 3. The through-hole 3 d penetrates from the inside of the rice cooker 100 toward the outside of the rice cooker 100. The through hole 3 d is a hole that is penetrated in the thickness direction of the so-called lid 3. The upper end portion 3da of the through hole 3d communicates with the bottom portion of the concave portion 3ba formed in the upper outer shell 3b. The steam cylinder 11 is detachably attached to the recess 3ba. The steam cylinder 11 is formed with a steam hole 11a opened to the outside.

  An inner lid 5 is attached to the lower outer shell 3 c of the lid body 3. A heating plate 14 is attached to the inner lid 5. The heating plate 14 applies heat from the lid 3 side to the object to be cooked placed in the pan 2. The heating plate 14 is formed with a steam escape hole 5a. Steam generated during rice cooking or heat insulation flows from the steam escape hole 5a to the outside of the rice cooker 100 through the through hole 3d and from the steam hole 11a. An annular packing 12 is attached to the opening of the through hole 3d. When the inner lid 5 is attached to the lid 3, the packing 12 is in close contact with the periphery of the steam escape hole 5 a formed in the inner lid 5. An inner lid temperature sensor can be attached to the inner lid 5 or the lower outer shell 3c. The inner lid temperature sensor can measure the temperature of the heating plate 14 during rice cooking or heat insulation.

  An inner lid heating unit 15 that heats the heating plate 14 is attached to the lid 3. In the present embodiment, an induction coil 15 a is used for the inner lid heating unit 15. The induction coil 15 a induction heats the heating plate 14 attached to the inner lid 5. On the lower outer shell 3c, the induction coil 15a is configured as a coil wound a plurality of turns in a planar shape. As another configuration, the inner lid heating unit 15 can use an electric resistance heater.

  An annular packing 13 is attached to the outer peripheral portion of the inner lid 5 on the surface where the inner lid 5 and the pan 2 face each other. The packing 13 is in close contact with the flange portion of the pan 2 when the lid 3 is closed.

  Inside the lid 3, a steam passage 16 and a steam passage heating unit 17 attached to the steam passage 16 are located. The steam passage 16 supplies superheated steam exceeding 100 ° C. toward the pot 2. The steam passage heating unit 17 heats steam at about 100 ° C. generated in the water tank 6 to generate superheated steam. In the lid 3, the inner lid heating unit 15 is located below the steam passage 16.

  The steam path heating unit 17 will be described in detail with reference to FIG.

  As shown in FIG. 4, the steam passage heating unit 17 is located on the outer peripheral side of the steam passage 16 so as to cover the steam passage 16. The steam passage heating unit 17 includes an induction coil 30 and a heat exchanger 31. The induction coil 30 heats the steam passage 16. The heat exchanger 31 is located between the induction coil 30 and the steam passage 16.

  In the present embodiment, the vapor passage 16 is made of austenitic stainless steel (SUS304), which is a nonmagnetic metal. With this configuration, when the induction coil 30 is energized, the induction coil 30 can induction-heat both the steam passage 16 and the heat exchanger 31. Since both the steam passage 16 and the heat exchanger 31 are sufficiently induction-heated, the steam taken into the steam passage 16 becomes superheated steam exceeding 100 ° C.

  The vapor passage 16 can be realized by depositing a thin film of nonmagnetic metal such as aluminum or titanium on the inner surface of the glass tube using a nonmetal such as a glass tube as a base material. The steam passage 16 may have another configuration, and is not limited to the above-described configuration.

  In addition, when the heat exchanger 31 is comprised with the nonmagnetic metal different from the steam path 16, there exists a possibility that potentiometric corrosion may generate | occur | produce. When potential difference corrosion occurs in the heat exchanger 31, the durability of the heat exchanger 31 decreases. Therefore, the heat exchanger 31 is preferably made of a nonmagnetic metal that is the same material as the steam passage 16. In the present embodiment, the heat exchanger 31 is made of austenitic stainless steel. As a result, the heat exchanger 31 can prevent the decrease in durability because the occurrence of potential difference corrosion is suppressed.

  An intake passage 32 is located at one end of the steam passage 16. The intake passage 32 supplies steam to the steam passage 16. When the lid 3 is in the closed state, the intake passage 32 communicates with the water tank 6. The intake passage 32 guides the steam generated in the water tank 6 to the steam passage 16. An intake passage restraint 33 connects the intake passage 32 and the steam passage 16. When the intake passage restraint portion 33 is attached to one end of the coil bobbin 34, the intake passage 32 is prevented from coming off so as not to come off from the steam passage 16.

  Next, as shown in FIG. 2, an annular packing 18 is attached between the lower outer shell 3 c of the lid 3 and the water tank 6. When the lid 3 is in the closed state, the packing 18 is in close contact with the flange portion 6 b included in the water tank 6.

  As shown in FIGS. 2 and 4, the other end of the steam passage 16 is bent toward the direction in which the opening 2 a included in the pan 2 is located. An overheated steam discharge hole 5 b is formed in the inner lid 5. The other end of the steam passage 16 communicates with the inside of the pan 2 via the superheated steam discharge hole 5 b formed in the inner lid 5. The annular packing 19 is attached so as to cover the other end of the steam passage 16. The outer periphery of the packing 19 is held by the steam passage restraining portion 37.

  In the steam passage 16, a caulking portion 16 d is formed in each portion where both ends of the heat exchanger 31 are located. Each crimping part 16d regulates that the heat exchanger 31 moves. The superheated steam temperature detector 35 is attached to the crimping part 16d formed on the packing 19 side in contact. The superheated steam temperature detector 35 detects the temperature of the superheated steam generated in the steam passage 16. A steam temperature detector 36 is attached in contact with the caulking portion 16d formed on the intake passage restraining portion 33 side. The steam temperature detection unit 36 detects the temperature of the steam sent into the steam passage 16.

Next, the operation when cooking rice using the rice cooker 100 in the present embodiment described above will be described in detail.

  As shown in FIGS. 1 and 2, the lid 3 includes a display unit 40 and an operation unit 45. Various information such as a rice cooking course and a rice cooking time is displayed on the display unit 40. The display unit 40 is configured by a liquid crystal display or the like.

  The user selects a desired operation from various options set in advance in the rice cooker 100 via the operation unit 45. As an example, a plurality of rice cooking courses are set in the rice cooker 100 in the present embodiment. There are white rice course, brown rice course, white rice (softer) course, etc. The operation unit 45 is configured so that a plurality of rice cooking courses can be selected. In addition, the operation part 45 can instruct | indicate functions, such as start of rice cooking, cancellation, and a reservation. As an example, the operation part 45 can be comprised by several operation buttons, such as a rice cooking start button.

  The user can select a desired rice cooking course with the operation unit 45 while confirming the content displayed on the display unit 40. The user can instruct execution of the selected rice cooking course via the operation unit 45.

  The control unit 41 is attached to the inside of the rice cooker body 1. The control unit 41 stores a control sequence for realizing various preset options. The control unit 41 includes a storage unit 41a that stores a control sequence. The memory | storage part 41a memorize | stores the some rice cooking sequence which cooks rice among control sequences. The rice cooking sequence mainly refers to a rice cooking procedure composed of four steps of a preheating step, a temperature raising step, a boiling maintenance step, and a steaming step. A rice cooking sequence is implemented in order of a preheating process, a temperature rising process, a boiling maintenance process, and a steaming process. For example, in order to realize each rice cooking course described above, various conditions in each step are predetermined for each rice cooking sequence. Various conditions include energization time, heating temperature, heating time, heating output, etc. in each step.

  As described above, the user selects a desired rice cooking course and instructs the start of rice cooking. In response to this instruction, the control unit 41 operates so as to realize the selected rice cooking course. Specifically, the temperature detected by each temperature sensor attached to the inside of the rice cooker 100 is input to the operation unit 45. The control unit 41 outputs an operation signal for operating each unit such as a heating unit based on the input temperature or the like.

  Operation | movement at the time of rice cooking is demonstrated using FIG. 2, FIG.

  The pot 2 in which rice and water are put is stored inside the rice cooker body 1. A water tank 6 attached to the rice cooker body 1 is filled with a predetermined amount of water. The user selects a desired rice cooking course via the operation unit (45) and instructs the control unit 41 to start cooking. The control unit 41 starts a predetermined rice cooking sequence.

  First, preheating process S1 is implemented as a rice cooking sequence.

  Preheating process S1 is a process which makes rice absorb water. In the preheating step S1, the rice is immersed in water having a temperature lower than the gelatinization temperature. The purpose of the preheating step S1 is to allow the rice to absorb water so that the rice is sufficiently gelatinized in the later-described step.

In preheating process S1, the control part 41 heats up so that the temperature in the pan 2 may become 60 degreeC vicinity. 60 ° C. is the temperature at which gelatinization of rice begins. When the temperature in the pan 2 is close to 60 ° C., the control unit 41 performs control so that the temperature in the pan 2 is maintained near 60 ° C. That is, the temperature of the pan 2 detected by the pan temperature sensor 10 is input to the control unit 41. The control unit 41 outputs an operation signal for heating the pan 2 to the pan bottom heating unit 8 based on the temperature of the pan 2. Therefore, it is promoted that rice sucks water.

  In the preheating step S1, the control unit 41 applies heat to the water in the water tank 6 to preheat the water. The controller 41 outputs an operation signal for heating the water in the water tank 6 to the water tank heating coil 7. If time preset according to the selected rice cooking course passes after the preheating process S1 is started, the control part 41 will transfer to temperature rising process S2.

  The temperature raising step S2 is a step for bringing the water put in the pan 2 into a boiling state. In the temperature raising step S2, the pan 2 is heated with a high output corresponding to a strong fire. Water becomes boiling (about 100 ° C.) in a short time. In temperature rising process S2, the control part 41 controls the pot bottom heating part 8 so that the water in the pot 2 will be in a boiling state in a short time. As a result of the temperature raising step S2, the temperature of the pan 2 detected from the pan temperature sensor 10 is close to 100 ° C. When the temperature of the pan 2 detected from the pan temperature sensor 10 is close to 100 ° C., the control unit 41 proceeds to the boiling maintenance step S3. In addition, the time required for temperature rising process S2 changes according to the quantity of the rice and water which are the to-be-cooked objects put into the pan 2, ie, the amount of rice cooking. In other words, the amount of cooked rice can be calculated from the time required for the temperature raising step S2.

  The boiling maintenance step S3 is a step of gelatinizing the starch of rice and raising the gelatinization degree of the gelatinized rice to about 50% to 80%. In order to gelatinize the starch of rice and raise the gelatinization degree of the gelatinized rice, it is necessary to maintain the boiling state of the water put in the pan 2 for a predetermined time.

  In the boiling maintenance step S3, the control unit 41 controls the pan bottom heating unit 8 and the inner lid heating unit 15 so as to maintain the state where the water put in the pan 2 is boiled. In the boiling maintenance step S3, the control unit 41 also adjusts the temperature of the water tank 6. Specifically, the control unit 41 controls the water tank heating coil 7 so as to maintain the water temperature of the water tank 6 warmed in the preheating step S1. In addition, in addition to the amount of rice cooking, the time required for boiling maintenance process S3 changes according to the selected rice cooking course.

  In the boiling maintenance step S3, the water put in the pan 2 continues to boil. Therefore, a large amount of steam at about 100 ° C. is generated in the pan 2. A large amount of generated steam is discharged from the steam escape hole 5a formed in the inner lid 5 through the through hole 3d to the outside of the rice cooker 100 through the steam hole 11a. In this way, water is almost lost from the inside of the pot 2. As a result, the temperature of the pot 2 measured through the bottom surface 2b of the pot 2 rises above the boiling point of water. Eventually, when the temperature of the pan 2 detected by the pan temperature sensor 10 reaches a predetermined temperature, which is 130 ° C. in the present embodiment, the control unit 41 proceeds to the steaming step S4.

  By the way, in boiling maintenance process S3, the control part 41 outputs the signal which drives the steam path heating part 17. FIG. The control unit 41 controls the steam passage heating unit 17 to heat the steam passage 16 and preheat the steam passage 16. Note that the steam passage 16 is heated by the energy applied from the inner lid heating section 15 during the period from the start of the preheating step S1 to the output of a signal for driving the steam passage heating section 17 from the control section 41. The steam passage 16 is preheated. The inner lid heating unit 15 is located below the steam passage 16.

  The steaming step S4 is a step of raising the degree of gelatinization of rice to nearly 100%. In order to raise the degree of gelatinization of rice to nearly 100%, it is necessary to evaporate excess water present in the pan 2 using residual heat.

In the steaming step S4, the control unit 41 causes the pan bottom heating unit 8 and the inner lid heating unit 1 to heat the pan 2 each time the temperature of the pan 2 detected by the pan temperature sensor 10 falls below a certain temperature.
5 is controlled.

  Specifically, the control part 41 performs duty control which turns ON / OFF the pan bottom heating part 8 at a fixed time interval similarly to the boiling maintenance process S3. That is, the control part 41 heats the pan 2 intermittently. Note that ON means a state in which the control unit 41 drives the pan bottom heating unit 8. OFF means a state in which the control unit 41 stops driving the pan bottom heating unit 8. The controller 41 drives the water tank heating coil 7 to boil the water in the water tank 6 and generate steam.

  Further, the control unit 41 controls the steam passage heating unit 17 in accordance with the state in which steam is generated by the water tank 6. In this way, the control unit 41 controls the steam path heating unit 17 so as not to be baked.

  Moreover, the control part 41 can produce | generate superheated steam by the following control. That is, the control unit 41 controls the water tank heating coil 7 to generate steam from the water put in the water tank 6. The generated steam moves into the steam passage 16. The control unit 41 drives the steam passage heating unit 17. The steam passage heating unit 17 heats the steam passage 16 and raises the temperature of the steam that has moved into the steam passage 16. In the steam passage heating unit 17, heat exchange is performed in a short time between the energy supplied from the steam passage heating unit 17 and the steam. That is, when the steaming step S4 is started, superheated steam that has reached the superheated steam temperature is generated in a short time. The generated superheated steam passes through the steam passage 16 and is discharged toward the pan 2 from the superheated steam discharge hole 5b formed in the inner lid 5. If the preset time passes according to the amount of rice cooking and the selected rice cooking course after the steaming process S4 is started, the control part 41 will end the steaming process S4.

  As is clear from the above description, in the rice cooker in the present embodiment, the inner lid heating unit is located between the steam passage and the inner lid. The inner lid heating unit is located below the steam passage.

  In the first step, which is a period from when rice cooking is started until a predetermined time has elapsed, the inner lid heating unit heats the inner lid. During this time, the inner lid heating unit can preheat the steam passage by heating the steam passage.

  The rice cooker in the present embodiment is configured such that the inner lid heating unit heats the inner lid in the second step, which is a period until the rice cooking is finished after the predetermined time has elapsed, and the steam passage heating unit. Heats the steam passage. During this time, the energy output from the inner lid heating unit is continuously transmitted to the steam passage. That is, the steam passage heating unit can use the inner lid heating unit as an auxiliary heating unit.

  That is, in the first step, the inner lid heating unit preheats the steam passage. In the second step, the inner lid heating unit supplementarily heats the steam passage.

  In other words, the steam passage heating unit heats the steam passage together with the inner lid heating unit in the second step with respect to the steam passage heated by the inner lid heating unit in the first step. Therefore, the steam passage heating unit can directly reduce the energy for heating the steam passage, and the superheated steam can be quickly taken out from the steam passage.

  As a result, the rice cooker in this Embodiment can reduce the energy consumed while heating efficiency improves.

Moreover, in the rice cooker in this Embodiment, the inner cover heating part which heats a steam path indirectly has less heat quantity which can be supplied to a steam path than the steam path heating part which heats a steam path directly. Therefore, in the preheating process until steam is generated, the steam passage heating unit preheats the steam passage. Can be prevented.

  The superheated steam generator disclosed in Patent Document 1 uses an electric resistance heater as a heat source. The electric resistance heater has a red hot part. The electric resistance heater applies heat to an object located in the vicinity of the electric resistance heater by the red hot part releasing heat. In contrast, the steam passage heating unit used in the rice cooker in the present embodiment uses an induction coil as a heat source. The induction coil can be heated by transmitting electric energy only to an object to be heated by the principle of electromagnetic induction. That is, since the induction coil is superior in that it has less energy loss than the electric resistance heater, the heating efficiency is improved. Furthermore, the rice cooker in this Embodiment can shorten the time which preheating requires rather than the rice cooker disclosed by patent document 1, and can supply superheated steam quickly in a pan in a steaming process. Therefore, the rice cooker in this Embodiment can improve rice cooking performance.

  In the rice cooker in the present embodiment, the inner lid heating unit that heats the heating plate uses an induction coil as a heat source. The electric resistance heater conducts heat conduction by heat radiation from the red hot part. The induction coil transmits electric energy only to an object to be heated by the principle of electromagnetic induction, and converts the transmitted electric energy into thermal energy. Therefore, the induction coil is superior to the electric resistance heater in terms of less energy loss due to the difference in the principle of transmitting energy, so that the heating efficiency is improved. Furthermore, the rice cooker in the present embodiment can further shorten the time required for preheating the steam passage heating unit. Therefore, the rice cooker in this Embodiment improves rice cooking performance.

  According to the rice cooker of this invention, while being able to shorten the preheating time by a steam channel | path heating part, energy saving property can be improved. The rice cooker of this invention can be applied suitably with respect to field | areas and uses, such as household use and business use.

1,201 Rice cooker body 1a Pot storage part 1b Bottom face 1c Upper frame 1ca Tubular part 1cb Flange part 1cc Water tank storage part 1d Coil base 1e Inner peripheral part 2, 202 Pot 2a, 201a Opening part 2b Bottom face 2c Side wall 2d Corner part 3, 203 Lid 3a Hinge shaft 3b Upper outer shell 3ba Recess 3c Lower outer shell 3d Through hole 3da Upper end 5 Inner lid 5a Steam escape hole 5b Superheated steam discharge hole 6, 206 Water tank (liquid tank)
6a Water tank temperature sensor 6b Flange part 7,207 Water tank heating coil 8 Pan bottom heating part 8a Bottom heating coil 8b Side heating coil 9 Ferrite 10 Pan temperature sensor 11 Steam cylinder 11a Steam hole 12, 13, 18, 19 Packing 14 Heating plate 15, 215 Inner lid heating part (second heating part)
15a Induction coil 16 Steam passage 16a Discharge port 16b Connecting portion 16c Body portion 16d Caulking portion 17 Steam passage heating portion (first heating portion)
DESCRIPTION OF SYMBOLS 30 Inductive coil 31 Heat exchanger 32 Intake passage 33 Intake passage restraint part 34 Coil bobbin 35 Superheated steam temperature detection part 36 Steam temperature detection part 37 Steam passage restraint part 40 Display part 41 Control part 41a Memory | storage part 45 Operation part 100,200 Rice cooker 204 Superheated steam generator

Claims (10)

The rice cooker body,
Housed in the rice cooker body, including an opening on one side and a bottom surface on the other,
A lid attached to the rice cooker body so as to be freely opened and closed;
An inner lid that is attached to the lid and covers the opening when the lid is closed with respect to the rice cooker body;
A liquid tank that is attached to the rice cooker body or the lid and stores liquid;
When the lid is attached to the lid body and the lid body is in a closed state with respect to the rice cooker main body, one end is connected to the liquid tank, and the other end includes a discharge port that opens toward the opening. A steam passage that discharges the steam whose state has been changed by heating the liquid stored in the liquid tank from the discharge port toward the opening;
A first heating unit attached to the steam passage for heating the steam passage;
A second heating unit attached to the lid for heating the inner lid;
Rice cooker with. The rice cooker according to claim 1, wherein the second heating unit is located between the inner lid and the steam passage. 2. The rice cooker according to claim 1, wherein the steam passage includes a body portion extending along a surface formed by the inner lid between a portion where the steam passage is connected to the liquid tank and the discharge port. 2. The rice cooker according to claim 1, wherein the second heating unit is located so as to intersect with the vapor passage between a portion where the vapor passage is connected to the liquid tank and the discharge port. 2. The rice cooker according to claim 1, wherein the first heating unit is attached to the vapor passage between a portion where the vapor passage is connected to the liquid tank and the discharge port. The first heating unit is attached to the vapor passage between the portion where the vapor passage is connected to the liquid tank and the discharge port,
The second heating unit is located at a position different from the portion to which the first heating unit is attached and intersects with the steam passage.
The rice cooker according to claim 1. The first heating unit includes
An induction coil;
A heat exchanger containing a non-magnetic metal;
The rice cooker as described in any one of Claims 1-6 which has. A first step in which the second heating unit heats the inner lid;
A second step in which the first heating unit heats the steam passage and the second heating unit heats the inner lid;
The rice cooker as described in any one of Claims 1-6 further provided with the control part which switches. It is the control method of the rice cooker as described in any one of Claims 1-6,
The period from the start of cooking until the object to be cooked that has been put inside the pan is boiled as a first step, the second heating unit heats the inner lid,
A period until cooking is completed after the object to be cooked put in the pan is boiled is a second step, the first heating unit heats the steam passage and the second A heating unit heats the inner lid;
Control method of rice cooker. In the first step, the second heating unit preheats the steam passage,
The method for controlling a rice cooker according to claim 9, wherein, in the second step, the second heating unit heats the steam passage in an auxiliary manner.

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