JP6706989B2 - rice cooker - Google Patents

Description

TECHNICAL FIELD The present invention relates to a rice cooker including a water supply unit for supplying water into a pot-shaped container.

Generally, users of rice cookers not only cook delicious rice with the rice cooker, but also the usability of the rice cooker (for example, it is not necessary to adjust the water level to match the water level scale of the pot-shaped container). ) And the rice cooker body size is compact.

In order to eliminate the need for water level adjustment, the weight sensor measures the weight of the pot-shaped container (rice cooker) containing the washed rice, and supplies the amount of water according to the measured weight from the water tank to the pot-shaped container. There has been proposed a rice cooker that supplies rice to the inside and starts cooking rice (see, for example, Patent Document 1). Further, there has been proposed a rice cooker having a function of supplying water heated by a feed water heating unit from a water supply tank into a pot-shaped container during rice cooking (see, for example, Patent Document 2).

JP, 9-98884, A JP, 2011-87615, A

However, since the rice cooker described in Patent Document 1 is equipped with the weight sensor, the number of parts is increasing, and as a result, there is a problem that the main body size is large.

Further, since the rice cooker described in Patent Document 2 has a water supply heating unit that heats water in the water supply tank, in addition to the heating unit that heats the pot-shaped container, the number of parts is increasing. As a result, there is a problem that the body size is large. In addition, when the water in the water supply tank, which is a place different from the pot-shaped container, is heated, the amount of power consumption required for cooking rice increases, which is a problem that is against energy saving.

The present invention has been made to solve the above-mentioned problems of the conventional art, and an object of the present invention is to provide a rice cooker that can be reduced in body size and power consumption while improving usability. ..

A rice cooker according to an aspect of the present invention includes a pan-shaped container that stores a heated object, a heating unit that heats the pan-shaped container, a water supply unit that supplies water to the pan-shaped container, and the heating in the rice cooking process. A rice cooker comprising a heating section and a control section for controlling the water supply section, wherein the control section supplies the water during the first step in which the heating amount by the heating unit per unit time is a first heating amount. When water is supplied to the part, the heating amount is the first period during at least one of a first period immediately after the water supply, a second period during the water supply, and a third period immediately before the water supply. The heating unit is controlled so as to execute the second step changed to the second heating amount larger than the heating amount.

According to the present invention, it is possible to reduce the body size and suppress the power consumption while improving the usability.

It is a figure which shows roughly the structure (a cross-section structure and the structure of a control system are included) of the rice cooker which concerns on Embodiment 1 to 4 of this invention. (A) is a rice cooker according to Embodiments 1 to 4, in which rice is immersed in an optimum amount of water at the time of starting rice cooking, and the pot bottom temperature and the cover temperature in the rice cooking process when rice is cooked (when water is not supplied) It is a figure which shows the time change of the temperature of a to-be-heated material, (b) is a figure which shows the time change of the electric power supplied to a heating coil in a rice cooking process. It is a flowchart which shows operation|movement in the rice cooking process of the rice cooker which concerns on Embodiment 1 of this invention. (A) is a figure which shows the time change of the pot bottom temperature and internal temperature in the rice cooking process of the rice cooker which concerns on Embodiment 1, (b) shows the time change of the electric power supplied to a heating coil in a rice cooking process. It is a figure which shows, (c) is a figure which shows the electricity supply period (water supply period) by the magnet pump in a rice cooking process (preheating process). It is a flowchart which shows operation|movement in the rice cooking process of the rice cooker which concerns on Embodiment 2 of this invention. (A) is a figure which shows the time change of the pan bottom temperature and internal temperature in the rice cooking process of the rice cooker which concerns on Embodiment 2, (b) shows the time change of the electric power supplied to a heating coil in a rice cooking process. It is a figure which shows, (c) is a figure which shows the electricity supply period (water supply period) by the magnet pump in a rice cooking process (heating process). It is a flowchart which shows operation|movement in the rice cooking process of the rice cooker which concerns on Embodiment 3 of this invention. (A) is a figure which shows the time change of the pan bottom temperature and internal temperature in the rice cooking process of the rice cooker which concerns on Embodiment 3, (b) shows the time change of the electric power supplied to a heating coil in a rice cooking process. It is a figure which shows, (c) is a figure which shows the electricity supply period (water supply period) by the magnet pump in a rice cooking process (boiling maintenance process). It is a flowchart which shows operation|movement in the rice cooking process of the rice cooker which concerns on Embodiment 4 of this invention. (A) is a figure which shows the time change of the pot bottom temperature and internal temperature in the rice cooking process of the rice cooker which concerns on Embodiment 4, (b) shows the time change of the electric power supplied to a heating coil in a rice cooking process. It is a figure which shows, (c) is a figure which shows the electricity supply period (water supply period) by the magnet pump in a rice cooking process (steaming process).

Embodiments of the present invention will be described below with reference to the drawings. The following description is an example, and the present invention is not limited to the embodiments described below. Further, the shapes, sizes, and ratios of dimensions of the constituent members shown in the drawings are merely examples, and various modifications are possible. Also, the control methods of the respective embodiments can be combined.

<<1>> Embodiment 1
(Rice cooker 100)
FIG. 1 is a diagram schematically showing a configuration (including a sectional structure and a configuration of a control system) of a rice cooker 100 according to Embodiment 1 (or Embodiments 2 to 4 described later) of the present invention. The rice cooker 100 is provided with a pot-shaped container (rice cooker) 1 for storing a food to be heated such as rice and water in a bottomed cylindrical main body (main structural part of the rice cooker 100) 10 and has a pot-like shape. It is a heating cooker that cooks cooked rice by heating an object to be heated housed in the container 1 with a heating coil 12 as a heating unit.

The rice cooker 100 is detachably attached to the pot-shaped container 1, the heating coil 12, and the main body 10, and controls the heating coil 12 and the water-feeding unit 30 in the rice cooking process, and the water supply unit 30 that supplies water into the pot-shaped container 1. And a control unit 18 for controlling. The control unit 18 controls the supply power (power supplied to the heating coil 12) in order to control the amount of heat (heating amount) by the heating coil 12 per unit time. When the control unit 18 supplies water to the pot-shaped container 1 by the water supply unit 30 during a period in which the heating amount per unit time (hereinafter, also simply referred to as “heating amount”) is the first heating amount, Immediately after the water supply, during the water supply, or immediately before the water supply, the power is supplied to the heating coil 12 so as to increase the heating amount to the second heating amount that is larger than the first heating amount. Control to increase. For example, when the control unit 18 performs the water supply by the water supply unit 30 during a period in which the heating amount per unit time is the first heating amount (for example, corresponding to the power supply P0 in FIG. 4B described later). Is the first period immediately after the water supply (for example, the period Q1 in FIG. 4B), the second period during the water supply (for example, the period Q2 in FIG. 9B described later), and the immediately before the water supply. In at least one of the three periods (for example, period Q3 in FIG. 6B described later), the second heating amount (eg, FIG. 4( The power supply to the heating coil 12 is controlled so as to be changed to (corresponding to the power supply P1 in b)).

Further, as shown in FIG. 1, the rice cooker 100 has a lid 20 installed in the main body 10 to open and close the opening of the main body 10 and cover the object to be heated in the opening of the pan-shaped container 1 when closed. is doing. In addition, the rice cooker 100 is provided with a water supply path 41 for guiding the water sent from the water supply unit 30 into the pot-shaped container 1, and various instructions are input by the user of the rice cooker 100 to display various information. An operation/display unit (also simply referred to as “operation unit”) 42 for performing the operation, and an internal temperature sensor (heated object temperature sensor) 43 for detecting the temperature in the pan-shaped container 1 (mainly the temperature of the heated object). The magnet pump 44 serves as a pump for supplying the water stored in the water tank 31 of the water supply unit 30 into the pan-shaped container 1. In addition, in FIG. 1, the control unit 18, the time measuring unit 17, and the signal line are drawn on the outside of the main body 10 of the rice cooker 100, but in reality, these configurations are the main body 10 of the rice cooker 100. Alternatively, it is provided inside the lid 20.

In the rice cooker 100, even if the water supply unit 30 that supplies water during the rice cooking process is not provided with a heater, the temperature drop during the rice cooking process due to water supply can be suppressed, and thus cooked rice can be cooked deliciously. .. In addition, when water at room temperature was supplied into the pot-shaped container 1 during the rice cooking process, the temperature inside the pot-shaped container 1 was immediately raised, and a rice cooking experiment was conducted to confirm the taste of cooked cooked rice. No decrease was confirmed. Moreover, since the rice cooker 100 includes the water supply unit 30, it is not necessary to adjust the water level to match the water level with the water level scale of the pot-shaped container, and the rice cooker is easy to use. Further, since the rice cooker 100 does not include the heater in the water supply unit 30, the main body size can be reduced and the power consumption can be suppressed. Below, each component and operation|movement of the rice cooker 100 are demonstrated in detail.

(Pot-shaped container 1)
Generally, the pot-shaped container 1 is a bottomed cylindrical container for containing an object to be heated. The pot-shaped container 1 is, for example, a container containing a magnetic metal that generates heat by induction heating. The pot-shaped container 1 has a flange portion 1 a protruding outward from the upper end of the pot-shaped container 1. However, the shape of the pot-shaped container 1 is not limited to the illustrated example.

(Main body 10)
The main body 10 includes a container cover 11 for accommodating the pan-shaped container 1, a heating coil 12 as a heating means (heating unit) for heating the pan-shaped container 1, and a temperature of the pan-shaped container 1 (“pan-shaped container temperature”). Alternatively, it has a pan bottom temperature sensor (container temperature sensor) 13 for detecting a “pan bottom temperature”) and a hinge portion 14 for supporting the lid 20 so as to be openable and closable. Further, inside the main body 10, a time measuring unit 17 that measures time, a control unit 18 that controls the operation of the entire apparatus, and an energization that measures a current value (or supply power) energized to the heating coil 12. A quantity measuring unit 19 is provided. The time measuring unit 17 is instructed by the control unit 18 to measure (count) the elapsed time from the start of each process. The elapsed time counted by the time measuring unit 17 is output to the control unit 18. Further, the energization amount measuring unit 19 integrates the amount of power supplied to the heating coil 12 instructed by the control unit 18, and notifies the control unit 18 of the integrated power amount (integrated power amount).

The container cover 11 is formed in a cylindrical shape with a bottom, and the pot-shaped container 1 is detachably accommodated therein. At the center of the bottom surface of the container cover 11, a hole portion 11a into which the pan bottom temperature sensor 13 is inserted is provided.

The heating coil 12 induction-heats the pot-shaped container 1 when a current controlled by the controller 18 is applied (that is, electric power is supplied). As the heating means for heating the pot-shaped container 1, other means such as a sheathed heater which is an electric heater may be used instead of the heating coil 12.

The pan bottom temperature sensor 13 is composed of, for example, a thermistor. The pan bottom temperature sensor 13 is inserted into the hole 11a of the container cover 11 and is biased upward by an elastic member (means for applying a pressing force) such as a spring. Therefore, when the pan-shaped container 1 is housed in the container cover 11, the pan-bottom temperature sensor 13 comes into contact with the bottom surface of the pan-shaped container 1 while being urged upward toward the bottom surface of the pan-shaped container 1. The pot bottom temperature sensor 13 sends temperature information (detection signal) indicating the detected temperature of the pot-shaped container 1 to the control unit 18. Note that the temperature detection position is not limited to the bottom of the pan, and the temperature detection position may be plural.

The hinge portion 14 is provided on one end side of the upper portion of the main body 10 (the left end side of the main body 10 in FIG. 1 ), and supports the lid body 20 so that the lid body 20 can be opened and closed so that the opening portion of the main body 10 can be opened and closed.

The time measuring unit 17 receives an instruction from the control unit 18, measures the elapsed time from the start of each process, and sends time information about the measured elapsed time to the control unit 18. The control unit 18 uses the temperature information received from the pan bottom temperature sensor 13, the time information received from the time measuring unit 17, the temperature information received from the internal temperature sensor 23, and the instruction information received from the operation/display unit 42. Based on this, the high-frequency current passing through the heating coil 12 and the current passing through the magnet pump 44 are controlled. The control unit 18 may be configured by hardware such as a control circuit that executes a control function. Further, the control unit 18 may be configured by a software program stored in the storage unit 18a such as a semiconductor memory and an arithmetic device such as a microcomputer or a CPU (central processing unit) that executes the software program.

(Lid 20)
The lid body 20 includes an outer lid 20a that constitutes an upper portion and side portions of the lid body 20, an inner lid 20b that is provided closer to the object to be heated than the outer lid 20a when the lid body 20 is closed, and a pot. And a cartridge 22 for discharging the steam in the container 1 to the outside of the rice cooker 100. Further, the lid body 20 is provided with a water supply path 41 between the outer lid 20a and the inner lid 20b. The inside of the pot-shaped container 1 is a region (space) surrounded by the pot-shaped container 1 and the inner lid 20b when the lid 20 is closed. However, the structure of the lid 20 is not limited to the illustrated example.

The outer lid 20 a is attached to the main body 10 so that the lid body 20 can open and close the opening of the main body 10 by the hinge portion 14. The outer lid 20a is attached to the surface of the inner lid 20b opposite to the main body 10 side via a locking member 21. A cartridge 22 is detachably attached to the outer lid 20a so that the steam in the pan-shaped container 1 is discharged from the lid steam port 20bB of the inner lid 20b. An internal temperature sensor 43 is installed on the inner lid 20b side of the outer lid 20a. The internal temperature sensor 43 is arranged so that it can be inserted into the lid hole portion 20bC of the inner lid 20b and detect the temperature inside the pan-shaped container 1.

The inner lid 20b is made of metal such as stainless steel. The inner lid 20b is attached to the surface of the outer lid 20a on the main body 10 side via a locking member 21. A lid packing 20bA made of a sealing material is attached to the peripheral portion of the inner lid 20b. When the lid body 20 is closed, the lid packing 20bA comes into close contact with the upper end portion inside the pot-shaped container 1 (the inner portion of the flange portion 1a of the pot-shaped container 1), and the pot-shaped container 1 and the inner lid 20b. The inside of the pot-shaped container 1 surrounded by is sealed from the outside. Further, the inner lid 20b is provided with a lid steam port 20bB for discharging the steam in the pan-shaped container 1 from the cartridge 22, and a lid hole portion 20bC into which the internal temperature sensor 43 is inserted. Further, the inner lid 20b is provided with a lid water supply port 20bD for allowing the water sent from the water supply unit 30 to flow into the pot-shaped container 1 from the lid side path port 41a of the water supply path 41. The lid water supply port 20bD is preferably configured by a plurality of through-holes provided at positions corresponding to the lid-side path port 41a of the water supply path 41, as shown in FIG. 1, for example. By providing the lid water supply port 20bD with a plurality of through holes, when water is supplied from the lid water supply port 20bD into the pot-shaped container 1, a recess can be formed in the water supply region on the upper surface of the rice contained in the pot-shaped container 1. Can be prevented. In addition, by providing the lid water supply port 20bD with a plurality of through holes, even if the through hole of the lid water supply port 20bD is clogged with rice grains during rice cooking, water is supplied from a through hole different from the clogged through hole. Therefore, it is possible to reduce the risk that all the through holes of the lid water supply port 20bD are clogged.

The cartridge 22 is removably attached to the outer lid 20a, and discharges the steam taken in from the steam inlet 22a for taking in the steam in the pan-shaped container 1 from the lid steam opening 20bB of the inner lid 20b. It has a steam outlet 22b. In general, the steam inlet 22a is provided with a valve (not shown) that moves up and down according to the steam pressure generated in the pan-shaped container 1 during the rice cooking process. It is discharged from the outlet 22b.

(Water supply section 30)
The water supply unit 30 has a water tank 31 that stores water for supplying water into the pan-shaped container 1 during the rice cooking process, and a tank lid 32 that is detachably fitted into an opening at the upper end of the water tank 31. There is. The water tank 31 is made of, for example, plastic and is detachably attached to the front surface side of the main body 10 (the opposite side of the hinge portion 14 of the main body 10). By setting the water tank 31 on the front side of the main body 10, the user can easily attach and detach the water tank 31 to and from the main body 10, and the water in the water tank 31 is accidentally spilled into the main body 10. The risk of splashing water on the main body 10 can be reduced. The tank lid 32 has a tank water supply port 32a joined to the tank side passage port 41b of the water supply route 41, a communication pipe 32b extending downward from the tank water supply port 32a, and a tank for communicating the inside and outside of the water supply unit 30. A ventilation hole 32c is provided. The water in the water tank 31 is sent out from the tank water supply port 32a to the water supply path 41 by the magnet pump 44 through the communication pipe 32b of the tank lid 32, and is supplied into the pot-shaped container 1. The water stored in the water tank 31 is put into the water tank 31 before the start of rice cooking. However, the structure of the water supply unit 30 is not limited to the illustrated example.

(Water supply route 41)
The water supply path 41 guides the water sent from the water supply unit 30 by the magnet pump 44 to the lid water supply port 20bD of the inner lid 20b and drops it in the pot-shaped container 1. The water supply path 41 is formed of a heat resistant resin or the like, and is detachably accommodated in the outer lid 20a. The water supply path 41 includes a lid side path opening 41a joined to the lid water supply opening 20bD of the inner lid 20b and a tank side path opening 41b joined to the tank water supply opening 32a of the water supply unit 30 when the lid 20 is closed. And a path 41c for sending water flowing in from the tank side path opening 41b to the lid side path opening 41a. At the peripheral edges of the lid-side passage opening 41a and the tank-side passage opening 41b, the lid-side passage opening 41a and the tank-side passage opening 41b are brought into close contact with the upper surface of the inner lid 20b and the upper surface of the tank lid 32 of the water supply unit 30, respectively, so that water is absorbed. It is desirable to have a packing of sealing material to prevent leakage. However, the structure of the water supply path 41 is not limited to the illustrated example.

(Operation/display unit 42)
The operation/display unit 42 is provided, for example, on the upper surface of the outer lid 20a. The operation/display unit 42 receives and inputs various instructions from the user of the rice cooker 100, such as starting and canceling rice cooking, setting the amount of rice cooked (rice cooked rice amount), and setting reservations. Various instructions are sent to the control unit 18 as instruction information. The operation/display unit 42, as various rice cooking information, a rice cooking menu (“standard rice” or “early rice cooked” for rice cooking time, “hard” or “soft rice” for hardness of cooked rice, rice cooked) Type, "white rice" or "non-washed rice", etc.), time information, the amount of cooked rice, etc. are displayed. The rice cooking program, which is suitable for the rice cooking menu and the instruction information such as the amount of rice cooked, received from the operation/display unit 42 is executed by the control unit 18. The control unit 18 controls the operations of the heating coil 12 and the magnet pump 44 in accordance with a rice cooking program suitable for the rice cooking menu and instruction information such as the amount of cooked rice to cook rice. However, the operation buttons in the operation/display unit 42 and the display unit (such as a liquid crystal panel) may be separately configured.

(Internal temperature sensor 43)
The internal temperature sensor 43 is installed, for example, on the surface of the outer lid 20a that faces the inner lid 20b, and is inserted into the lid hole portion 20bC of the inner lid 20b. The internal temperature sensor 43 detects the temperature above the object to be heated in the pan-shaped container 1. Therefore, the internal temperature is also referred to as "heated object temperature". The internal temperature sensor 43 is composed of, for example, a thermistor. The internal temperature sensor 43 sends temperature information about the detected temperature inside the pan-shaped container 1 to the control unit 18.

(Magnet pump 44)
The magnet pump 44 has a magnet pump motor 44a and an impeller casing 44b having an impeller 44bA inside. The magnet pump motor 44a is installed in the main body 10, and the impeller casing 44b is installed in the communication pipe 32b of the water supply unit 30. When the magnet pump motor 44a operates, the magnet 44aA attached to the magnet pump motor 44a rotates, and the rotation of the magnet 44aA causes the magnet 44bB attached to the impeller 44bA in the impeller casing 44b to rotate and the impeller 44bA. Rotates. The magnet 44aA attached to the magnet pump motor 44a is, for example, installed in the main body 10, and the magnet 44bB attached to the impeller 44bA is, for example, in the water tank 31 between the impeller 44bA and the magnet pump motor 44a. It is installed. When the impeller 44bA in the impeller casing 44b rotates, the water stored in the water tank 31 is supplied to the pot-shaped container 1 through the communication pipe 32b and the water supply path 41. The current supplied to the magnet pump 44, that is, the current for operating the magnet pump motor 44a is controlled by the controller 18. When the amount of water supplied from the water supply unit 30 into the pot-shaped container 1 (water supply amount) is the same (constant), the magnet pump 44 is energized for a long time. Proportional to

(Other configurations)
The main body 10 may be provided with a handle for carrying the rice cooker 100. The handles are, for example, at two positions on one end side and the other end side of the main body 10, and substantially at the front-rear center of the upper side surface of the main body 10 (between the rear portion provided with the hinge portion 14 and the front portion provided with the water supply portion 30). It may be rotatably supported at two locations (approximately the center) and rotatably connect the two locations. It is desirable that the rotation axis of the handle be substantially parallel to the rotation axis of the hinge portion 14. In this case, when the carrier of the rice cooker 100 lifts the rice cooker 100 with the handle, the handle rotates to a position almost directly above the rotation axis, and the user (carrier) holds the rice cooker 100 only. Can be transported.

Next, the rice cooking process performed when rice is cooked in the rice cooker 100 will be described. The rice cooking process generally includes a preheating process, a temperature raising process, a boiling maintaining process, and a steaming process. When rice cooking is started, the preheating process of the rice cooking process is started.
The preheating step is a step of preheating an object to be heated containing rice and water, and heating the pan-shaped container 1 at a stage before the water in the pan-shaped container 1 boils (for example, the object to be heated is predetermined). This is a step of heating at a temperature for a predetermined time), thereby promoting water absorption of rice, and producing a taste component such as sugar as a sweet component or amino acid as a umami component.
The temperature raising step is a step of heating the pan-shaped container 1 until the object to be heated in the pan-shaped container 1 boils after the preheating step is completed.
The boiling maintaining step is a step of heating the pan-shaped container 1 so as to maintain boiling of water in the pan-shaped container 1 to promote gelatinization of starch of rice.
The steaming step is a step of heating the pan-shaped container 1 so that the rice is steamed, and the starch in the center of the cooked rice grain is sufficiently gelatinized to make the distribution of water in the cooked rice grain uniform. This is a step of heating the container 1.
When the steaming process ends, the rice cooking process ends.

Fig. 2(a) shows a case where rice is soaked in the optimum amount of water for the amount and nature of the rice to be cooked in the rice cooker 100 according to the first embodiment when the rice is cooked (water is supplied. It is a figure which shows the time change of the pan bottom temperature and the temperature of the to-be-heated material in the pan-shaped container 1 in a rice cooking process (when there is no), and FIG.2(b) is the time of the electric power supplied to the heating coil 12 in a rice cooking process. It is a figure which shows change. The horizontal axes of FIGS. 2A and 2B show the elapsed time from the start of rice cooking, the vertical axis of FIG. 2A shows the temperature, and the vertical axis of FIG. 2B is supplied to the heating coil 12. Indicates the power consumption. 2A shows the temperature of the pan-shaped container 1 detected by the pan-bottom temperature sensor 13 (pot-bottom temperature), and the dotted line in FIG. 2A indicates the pan-shaped container detected by the internal temperature sensor 43. 1 shows the temperature of the object to be heated (internal temperature). As shown in FIGS. 2(a) and 2(b), when rice cooking is started at the optimum amount of water for the amount and nature of rice at the start of rice cooking, water is not supplied during the rice cooking process, and water is temporarily supplied. The temperature is not lowered, and the amount of electric power supplied to the heating coil 12 during water supply is not adjusted (increased).

Next, water supply in the rice cooking process of the rice cooker 100 and control at the time of water supply will be described. FIG. 3 is a flowchart showing an operation in the rice cooking process of rice cooker 100 according to the first embodiment. FIG. 4A is a diagram showing a temporal change of the pot bottom temperature and the internal temperature in the rice cooking process of the rice cooker 100 according to the first embodiment, and FIG. 4B is supplied to the heating coil 12 in the rice cooking process. It is a figure which shows the time change of the electric power which is carried out, and FIG.4(c) is a figure which shows the electricity supply period (water supply period) by the magnet pump 44 in a rice cooking process (preheating process).

Before operating the rice cooker 100, the user may use rice (rice after washing rice or non-washed rice) and an arbitrary amount smaller than the water level scale according to the amount of rice (for example, the water surface is higher than the upper surface of the rice. Prepare a pot-shaped container 1 containing (amount of) water. In the conventional rice cooker 100, the water level scale generally matches the water level on a scale having a thickness of about 1 mm to 2 mm. However, since the rice cooker 100 has a paper feeding function, the water level scale is less than the water level scale. Just add a little water. By using an arbitrary amount of water that is smaller than the scale, it is possible to reduce the trouble of adjusting the water level as compared with the conventional method.

Next, the user stores the pan-shaped container 1 in the container cover 11 in the main body 10 and sets the water tank 31 containing water in the main body 10. Then, the user closes the lid 20, selects the rice cooking menu on the operation/display unit 42, sets the amount of rice to be cooked (for example, 3 cups), and presses the rice cooking switch on the operation/display unit 42. Instruct the rice cooker 100 to start cooking rice. The rice cooker 100 starts rice cooking when the user presses the rice cooking switch to give an instruction to start rice cooking.

When rice cooking is started, first, a preheating process is executed (step S1a). When the preheating process is started, the time measuring unit 17 starts measuring the elapsed time from the start of the preheating process (step S101), and the heating coil 12 is supplied to the heating coil 12 based on the time and power supplied by the energization amount measuring unit 19. The integrated value of the supplied electric energy (integrated electric energy) is measured (step S102).

Next, the control unit 18 controls the power supply to the heating coil 12 to be turned on/off based on the information indicating the pan bottom temperature detected by the pan bottom temperature sensor 13, so that the temperature of the pan-shaped container 1 is approximately the target temperature θa in the preheating step. The pan-shaped container 1 is heated so as to maintain it. The target temperature θa in the preheating process is a temperature at which gelatinization of starch does not occur. In other words, if the pan bottom temperature is (θ−α)° C. or lower (α is a positive value indicating the temperature, for example, α=2° C.) (YES in step S103), the control unit 18 sets the heating coil 12 to the heating coil 12. Is turned on (step S104), and if the pot bottom temperature exceeds (θ-2)° C. (NO in step S103), it is determined whether the pot bottom temperature is higher than the target temperature θa (step S105). ). Here, when the pot bottom temperature is higher than the target temperature θa (YES in step S105), the control unit 18 turns off (interrupts) the power supply to the heating coil 12 (step S106). After step S104, or after step S106, or when the determination is NO in step S105, the control unit 18 determines whether or not the elapsed time from the start of the preheating step is the reference time t0 or more ( In step S107), if it is less than the reference time t0 (NO in step S107), the processes of steps S103 to S106 are repeated.

If the elapsed time from the start of the preheating process is equal to or longer than the reference time t0 (YES in step S107), the control unit 18 sets the energization amount measured by the energization amount measuring unit 19 and the rice set in the operation/display unit 42. The amount of water supplied to the pot-shaped container 1 (water supply amount) is calculated based on the amount (step S108). That is, the greater the measured amount of electricity, the greater the total amount of rice and water that are the objects to be heated contained in the pan-shaped container 1. The control unit 18 estimates (calculates) the amount of water contained in the pan-shaped container 1 from the predicted total amount of the objects to be heated and the amount of rice set in the operation/display unit 42, and from this calculated value The amount of water to be supplied into the pot-shaped container 1 is calculated.

The control unit 18 drives the magnet pump 44 according to the calculated water amount. That is, the control unit 18 performs control for energizing the magnet pump 44 for an energizing time (FIG. 4C) such that the calculated amount of water is supplied into the pan-shaped container 1 (step S109).

Next, the control unit 18 supplies the power P0 (500 W, duty ratio) until the pan bottom temperature becomes equal to or higher than the threshold temperature θb (θb≧θa) (NO in step S110). The heating coil 12 is energized so that the electric power P1 (for example, 500 W and the duty ratio 13/16) is higher than 10/16) (step S111). Here, the energization rate of 10/16 means that the energization time per second is (10/16) seconds.

Next, when the pan bottom temperature becomes equal to or higher than the threshold temperature θb (YES in step S110), the control unit 18 controls the on/off of the power supply to the heating coil 12 so that the temperature of the pan-shaped container 1 generally maintains the target temperature θa. The pan-shaped container 1 is heated. In other words, if the pan bottom temperature is (θ−β)° C. or lower (β is a positive value indicating the temperature, for example, β=2° C.) or lower (YES in step S112), the control unit 18 heats the heating coil. When electricity to 12 is turned on (step S113) and the pot bottom temperature exceeds (θ-2)° C. (NO in step S112), it is determined whether the pot bottom temperature is higher than the target temperature θa (step). S114). Here, when the pot bottom temperature is higher than the target temperature θa (YES in step S114), the control unit 18 turns off (interrupts) the power supply to the heating coil 12 (step S115). After step S113, or after step S1115, or when the determination is NO in step S114, the control unit 18 determines whether the elapsed time from the start of the preheating step is the reference time t1 or more ( In step S107), if it is less than the reference time t1 (NO in step S116), the processes of steps S112 to S115 are repeated.

If the elapsed time from the start of the preheating process is equal to or longer than the reference time t1 (YES in step S116), the control unit 18 ends the preheating process, executes the temperature raising process (step S2), and after the temperature raising process. The boiling maintaining process (step S3) is executed, and then the steaming process (step S4) is executed, and the rice cooking process is completed.

As described above, according to the rice cooker 100 according to the first embodiment, by heating the electric power supplied to the heating coil 12 immediately after the water supply is higher than that in the process immediately before the water supply, the pot-shaped container 1 is supplied by the water supply. Even if the internal temperature decreases, the temperature can be immediately increased, and the deterioration of the taste can be suppressed. In an actual rice cooking experiment, it was confirmed that even if normal temperature water was supplied from the water supply part to the pot-shaped container, the taste was hardly deteriorated when the internal temperature was immediately increased.

In addition, according to the rice cooker 100 according to the first embodiment, it is not necessary to add a component such as a weight sensor that is not mounted in a general rice cooker, but an electric current that is also mounted in a general rice cooker. By using the amount measuring unit 19, the amount of water to be supplied into the pan-shaped container 1 can be calculated based on the amount of electricity supplied during the rice cooking process. Therefore, the size of the main body 10 can be reduced.

Further, it is not necessary to preheat the water to be supplied before it is put into the pan-shaped container 1, that is, it is necessary to provide the water tank 31 or the water supply path 41 with a water supply heating unit having a configuration different from the heating coil 12. Since it does not exist, it is possible to suppress an increase in the number of parts. If the feed water heating unit is provided, the size of the main body 10 is increased because an air passage or a space is provided so as not to overheat not only the heating coil 12 but also the space for installing the heat insulating material or the parts. In the first embodiment, it is possible to reduce the trouble of adjusting the water level (improve usability) while suppressing an increase in the size of the main body 10.

Further, according to the rice cooker according to the first embodiment, it is not necessary to heat the water to be supplied in a place different from the pot-shaped container 1, so that the power consumption required for cooking rice can be reduced and the effect of energy saving can be obtained. Obtainable.

Further, according to the rice cooker 100 according to the first embodiment, in the preheating step, the pot-shaped container 1 is heated at the target temperature θa such that gelatinization of starch does not occur, and water absorption into rice grains is promoted. If the pot-shaped container 1 is heated at a temperature higher than the gelatinization temperature to perform the preheating process, the inside of the pot-shaped container 1 has a difference in water absorption speed between a portion close to a portion where heat is generated by the heating coil 12 and a portion far therefrom. Becomes larger, unevenness in water absorption occurs, and eventually unevenness in cooking occurs. Therefore, in the first embodiment, the electric power P1 (P1>P0) is supplied to the heating coil 12 for strong heating not immediately before the water is supplied into the pot-shaped container 1 but during the period Q1 immediately after the water is supplied. Before the water is supplied, the pot-shaped container 1 is easily overheated and easily reaches the gelatinization temperature or higher, so that the temperature of the pot-shaped container 1 and the object to be heated in the pot-shaped container 1 are lowered after the water supply. By strongly heating the electric power P1 after the state, the pot-shaped container 1 is controlled so as not to reach the gelatinization temperature or higher. Further, it is desirable that the threshold temperature θb used for the determination for stopping the heating with the electric power P1 is equal to or higher than the target temperature θa and lower than the gelatinization temperature.

In addition, by supplying water in the preheating process which is the initial stage of rice cooking, the ideal rice cooking process shown in Fig. 2 (when rice and a proper amount of water are contained in the pot-shaped container 1 before starting rice cooking) It is possible to obtain cooked rice that has been cooked in almost the same good condition as rice cooked.

<<2>> Embodiment 2
In the second embodiment, a rice cooker that supplies water into the pan-shaped container 1 in the temperature raising step in the rice cooking step will be described. The structure of the rice cooker according to the second embodiment is the same as that of the rice cooker 100 shown in FIG. 1. Therefore, FIG. 1 is also referred to in the description of the second embodiment. Further, the water supply and heating control method adopted by the rice cooker according to the second embodiment can be combined with the paper feeding and heating control method according to any of the first, third, and fourth embodiments.

FIG. 5 is a flowchart showing an operation in the rice cooking process of the rice cooker according to the second embodiment. 5, steps that are the same as or correspond to the step numbers shown in FIG. 3 are assigned the same step numbers as the step numbers in FIG. FIG. 6( a) is a diagram showing a temporal change of the pot bottom temperature and the internal temperature in the rice cooking process of the rice cooker according to the second embodiment, and FIG. 6( b) is supplied to the heating coil 12 in the rice cooking process. It is a figure which shows the time change of electric power, and FIG.6(c) is a figure which shows the electricity supply period (water supply period) by the magnet pump 44 in a rice cooking process (heating process).

Below, the rice cooker which concerns on Embodiment 2 is demonstrated focusing on a temperature rising process (step S2b). In the rice cooker according to the second embodiment, preparations before starting the rice cooking process are the same as those in the first embodiment.

When the user presses the rice cooking switch to start cooking rice, the preheating process starts. The control unit 18 controls the power supply to the heating coil 12 to be turned on and off based on the information indicating the pot bottom temperature, and heats the pot-shaped container 1 so that the temperature of the pot-shaped container 1 generally maintains the target temperature θa in the preheating step. To do. In other words, if the pan bottom temperature is (θ−α)° C. or lower (for example, α=2° C.) (YES in step S103), the control unit 18 turns on the heating coil 12 (step S104), When the pot bottom temperature exceeds (θ−2)° C. (NO in step S103), it is determined whether the pot bottom temperature is higher than the target temperature θa (step S105). Here, when the pot bottom temperature is higher than the target temperature θa (YES in step S105), the control unit 18 turns off (interrupts) the power supply to the heating coil 12 (step S106). After step S104, or after step S106, or when the determination is NO in step S105, the control unit 18 determines whether or not the elapsed time from the start of the preheating step is the reference time t1 or more ( If it is less than the reference time t1 (step S116) (NO in step S116), the processes of steps S103 to S106 are repeated.

If the elapsed time from the start of the preheating process is equal to or longer than the reference time t1 (YES in step S116), control unit 18 ends the preheating process and starts the temperature raising process (step S2b). The control unit 18 uses the energization amount measured by the energization amount measurement unit 19 (corresponding to the supplied integrated electric energy and the heating amount) and the rice amount set in the operation/display unit 42 to form a pot-shaped container. The amount of water (water supply amount) supplied into 1 is calculated (step S201). That is, the greater the measured amount of electricity, the greater the total amount of rice and water that are the objects to be heated contained in the pan-shaped container 1. The control unit 18 estimates (calculates) the amount of water contained in the pan-shaped container 1 from the predicted total amount of the objects to be heated and the amount of rice set in the operation/display unit 42, and from this calculated value The amount of water to be supplied into the pot-shaped container 1 is calculated.

Next, the time measuring unit 17 starts measuring the elapsed time (step S202), and the control unit 18 supplies the power P2 (equivalent to the heating amount per unit time) with the power P2 (for example, 1000 W and the energization rate 50/). The heating coil 12 is energized to heat the pot-shaped container 1 (Step S203).

When it is determined that the elapsed time from the start of the temperature raising step measured by the time measuring unit 17 is the reference time t2 or more (YES in step S204), the control unit 18 supplies the supplied power (the heating amount per unit time). The heating coil 12 is energized (correspondence) such that the electric power P3 is larger than the electric power P2 (for example, 1200 W, the duty ratio is 60/60) (step S205). When the pan bottom temperature sensor 13 detects a temperature equal to or higher than the upper limit temperature θc at which the cooked rice does not burn (YES in step S206), the control unit 18 sets the magnet pump 44 so that the calculated water supply amount is supplied into the pan-shaped container 1. It drives (step S207). The object to be heated in the pan-shaped container 1 before water supply is more likely to be burnt as the amount of water is smaller. It is possible to prevent the cooked rice on the bottom of the kettle from burning by determining the end timing of the heating with the supplied power as the power P3 based on the upper limit temperature θc at which the cooked rice does not burn.

When the water supply (step S207) is finished, the controller 18 energizes the heating coil 12 so that the supplied power becomes the power P2 (step S208). When the control unit 18 determines that the internal temperature sensor 43 is equal to or higher than the temperature θd for detecting the boiling of the object to be heated in the pan-shaped container (YES in step S209), the rice cooking process is changed from the heating process to the boiling maintaining process. Move to. After the temperature raising step (step S2b), the control unit proceeds to the boiling maintaining step (step S3) and the steaming step (step S4), and the rice cooking step ends.

As described above, according to the rice cooker according to the second embodiment, the pot-shaped container 1 is preheated by the heating coil 12 immediately before the water is supplied, and then the water is supplied. Since the temperature decrease of the object to be heated in 1 is small, the deterioration of the taste of cooked cooked rice is suppressed.

In addition, since the heating step (step S2b) is a step of heating with relatively large electric power in the rice cooking step, the inside of the pot-shaped container 1 is located at a place where the heating coil 12 causes the pot-shaped container 1 to generate heat. There is a large temperature difference between the near part and the far part. By supplying water in the temperature raising step (step S2b), a large convection occurs in the pan-shaped container 1 due to the water flow at the time of water supply, and the temperature difference of the object to be heated in the pan-shaped container 1 can be reduced, so that water absorption It is possible to suppress unevenness, and eventually prevent uneven cooking.

In addition, in the second embodiment, the process of supplying the power P3 to the power P3 and immediately after heating the pot-shaped container 1 (FIG. 6(c)) is not performed, but the heating or the energization is performed. An additional step of blocking may be inserted between step S206 and step S207 of FIG. This is because the heating step (step S2b) is a state in which a part of the object to be heated is starting to boil, and immediately after step S206, the pressure in the pan-shaped container 1 is slightly increased. This is because the water supply speed is slightly slow. That is, by inserting a step of heating with an electric power of P2 or less or an additional step of interrupting energization to suppress boiling and then supplying water, the inside of the pot-shaped container 1 can be supplied with a large water flow without reducing the water supply rate. This is because water can be supplied to. In addition, before the temperature of the pot-shaped container 1 or the temperature of the object to be heated becomes lower than the temperature immediately after the end of step S204, the step of heating with the power of P2 or less or the additional step of interrupting the energization is performed. It is desirable to do.

In the second embodiment, the case where the calculation of the water supply amount is calculated based on the energization amount in the preheating process (step S1b) has been described. However, the temperature increase rate (reference time t2 or The water supply amount may be calculated from the temperature change amount of the pan bottom temperature or the internal temperature at time t2+t3. That is, the larger the temperature rising speed, the larger the total amount of rice and water that are the objects to be heated contained in the pan-shaped container 1. The amount of water contained in the pot-shaped container 1 can be estimated from the predicted total amount of the heated object and the amount of rice set on the operation/display unit 42.

In the second embodiment, heating is performed with the power P3 until the pot bottom temperature sensor 13 detects the temperature θc or more immediately before the water supply, but the power P3 is not based on the temperature information but on the elapsed time from the start of the temperature raising process. You may judge the timing which finishes heating. That is, you may heat with the electric power P3 only for the preset time. At this time, it is desirable to set the above-mentioned set time longer as the amount of water supplied increases. Further, the above-mentioned set time may be set to a time such that the heat energy required for raising the supplied water amount from the normal temperature to the boiling temperature can be supplied to the pot-shaped container 1 with the electric power P3. desirable.

Further, in the second embodiment, as in the case of the first embodiment, the electric power P3 may be used for heating after water supply. In the temperature raising step, the water absorption rate of rice grains is higher than in the preheating step, so if the pot-shaped container 1 is heated with a large electric power P3 before water supply, the pot bottom (the inner bottom of the pot-shaped container) may be dried or burnt. Although there is a possibility, it is possible to prevent drying and burning by heating with electric power P3 after water supply.

<<3>> Embodiment 3
In the third embodiment, a rice cooker that supplies water into the pan-shaped container 1 in the boiling maintaining step in the rice cooking step will be described. The structure of the rice cooker according to the third embodiment is the same as that of the rice cooker 100 shown in FIG. Therefore, FIG. 1 is also referred to in the description of the third embodiment. Further, the water supply and heating control method adopted by the rice cooker according to the third embodiment can be combined with the paper feeding and heating control method according to any of the first, second, and fourth embodiments.

FIG. 7: is a flowchart which shows operation|movement in the rice cooking process of the rice cooker which concerns on Embodiment 3. In FIG. 7, steps that are the same as or correspond to the step numbers shown in FIGS. 3 and 5 are given the same step numbers as the step numbers in FIGS. 3 and 5. Fig.8 (a) is a figure which shows the time change of the pot bottom temperature and internal temperature in the rice cooking process of the rice cooker which concerns on Embodiment 3, and FIG.8(b) is supplied to the heating coil 12 in a rice cooking process. It is a figure which shows the time change of electric power, and FIG.8(c) is a figure which shows the electricity supply period (water supply period) by the magnet pump 44 in a rice cooking process (heating process).

Below, the rice cooker which concerns on Embodiment 3 is demonstrated centering around a boiling maintenance process (step S3c). In the rice cooker according to the third embodiment, preparations before starting the rice cooking process are the same as those in the first embodiment. When the rice cooker switch of the rice cooker is pressed by the user and the rice cooker starts the rice cook process, first, the preheating process (step S1) is started. When the preheating process ends, the temperature raising process (step S2) is executed, and then the boiling maintaining process (step S3c) is executed. When the boiling maintaining process ends, the steaming process (step S4) is executed. The preheating step, the temperature raising step, and the steaming step are the same as those described in any of the first, second, and fourth embodiments.

When the temperature raising process ends, the process moves to the boiling maintaining process (step S3c). When the boiling maintaining process (step S3c) starts, the control unit 18 sets the energization amount (corresponding to the heating amount) in the preheating process (step S1) measured by the energization amount measuring unit 19 and the operation/display unit 42. Based on the amount of rice, the amount of water supplied to the pot-shaped container 1 (water supply amount) is calculated (step S301). The amount of water supply is determined by the temperature of the pan bottom temperature (the detection value of the pan bottom temperature sensor 13) or the internal temperature (the detection value of the internal temperature sensor 43) in the temperature raising step (step S2) as described in the second embodiment. It may be obtained from the rising speed.

Next, the control unit 18 energizes the heating coil 12 so that the power supplied to the heating coil 12 (corresponding to the heating amount per unit time) becomes the power P4 (for example, 1000 W, the duty ratio 12/16). Perform (step S302). When the control unit 18 detects that the pot bottom temperature detected by the pot bottom temperature sensor 13 is equal to or higher than the upper limit temperature θe at which rice does not burn (YES in step S303), the storage unit 18a stores the internal temperature sensor 43 of that time. The detected temperature (internal temperature) θf is stored as a reference temperature (step S304).

Next, the control unit 18 energizes the heating coil 12 so that the supplied power becomes the power P5 larger than the power P4 (for example, 1200 W, the duty ratio 16/16) (step S305), and the calculated water supply amount. The magnet pump 44 is driven so that is supplied into the pan-shaped container 1 (step S306). The control unit 18 continuously energizes the heating coil 12 so that the supplied power becomes the power P5 (step S307), and when it is determined that the internal temperature is equal to or higher than the reference temperature θf (YES in step S308). The heating coil 12 is energized so that the supplied power becomes the power P4 (step S309).

Next, when it is determined that the pot bottom temperature is equal to or higher than the preset reference temperature θg (YES in step S310), the control unit 18 ends the boiling maintaining step and shifts to the steaming step (step S4). In addition, the fact that the pot bottom temperature reaches the reference temperature θg means that almost all the water in the pot-shaped container 1 is absorbed by the rice grains (the state in which there is no water that has not been absorbed by the rice grains). Is shown. When the steaming process (step S4) ends, the rice cooking process ends.

As described above, according to the rice cooker according to the third embodiment, the power is higher than the power P4 in the periods Q2 and Q4 that start at the same time as the water supply (or in parallel with the water supply or during the water supply). By heating with the electric power P5, the temperature of the pot-shaped container 1 does not excessively rise due to the effect of the temperature decrease due to the water supply and the action of the temperature increase due to the increase of the supplied power, and the inside of the pot-shaped container 1 is heated. The temperature of the object does not drop excessively. For this reason, excessive heating of the pan-shaped container 1 (for example, local excessive heating) causes charring of cooked rice, and excessive decrease in internal temperature causes insufficient gelatinization of starch in cooked rice or deterioration of eating quality such as fluffy rice grains. It is possible to suppress the occurrence of a state that causes it.

Further, according to the rice cooker according to the third embodiment, the heating with the electric power P5 is continued until the internal temperature becomes equal to or higher than θf which is the internal temperature immediately before reaching the temperature at which the water supply is started. Things are heated just enough. If the heating is terminated at a temperature lower than the temperature θf, the starch in the cooked rice is insufficiently gelatinized, and if the heating is terminated at a temperature higher than the temperature θf, the heating becomes excessive and water is evaporated more than necessary. It will be cooked hard. In order not to cause these problems, it is desirable to finish the heating with the electric power P5 when the internal temperature is θf.

Further, when the rice grains are immersed in water, the components of the rice grains are eluted into the water. The higher the water temperature, the more easily the components elute. When the rice cooking process progresses and all the water in the pan-shaped container 1 is absorbed by the rice grains, the eluted components, especially starch, are reattached to the surface layer of the rice grains to form a luster of the rice grains. That is, according to the rice cooker according to the third embodiment, since water is supplied in the boiling maintaining process, the state in which the rice grains are immersed in water at a high temperature can be maintained for a longer period of time than in normal rice cooking. , You can cook shiny rice.

Further, in the third embodiment, as in the case of the first embodiment, the power may be increased to heat strongly immediately after the water supply is finished. In the boiling maintaining process, the water absorption of rice grains progresses rapidly, so if the pan-shaped container 1 is heated with a large electric power P5 before water supply, the cooked rice near the bottom inside the pan-shaped container 1 may be dried or the cooked rice may burn. There is also a nature. However, heating with the power P5 immediately after water supply can prevent drying and burning.

In addition, in the third embodiment, as in the case of the second embodiment, the water may be supplied after the electric power is raised and heated before the water is supplied. By raising the temperature of the pot-shaped container 1 before water is supplied, the temperature of the supplied water can be immediately raised and the water can be brought into a boiling state quickly. When the rice temperature is lowered in the boiling maintaining step, the gelatinization of the starch is not sufficiently angry and the taste is deteriorated. Therefore, it is desirable to raise the temperature of the object to be heated as soon as possible. In addition, when water in liquid state is in contact with rice grains for a long time, the rice grains become fuzzy and the texture deteriorates, but in the state of steam, the rice grains do not become moist, so from the viewpoint of preventing texture deterioration. It is desirable to raise the temperature of the object to be heated as soon as possible.

<<4>> Fourth Embodiment
In the fourth embodiment, a rice cooker that supplies water into the pan-shaped container 1 in the steaming step in the rice cooking step will be described. The structure of the rice cooker according to the fourth embodiment is the same as that of the rice cooker 100 shown in FIG. Therefore, FIG. 1 is also referred to in the description of the fourth embodiment. Further, the water supply and heating control method adopted by the rice cooker according to the fourth embodiment can be combined with the paper feeding and heating control method according to any of the first to third embodiments.

FIG. 9: is a flowchart which shows operation|movement in the rice cooking process of the rice cooker which concerns on Embodiment 4. In FIG. 9, steps that are the same as or correspond to the step numbers shown in FIGS. 3, 5, and 7 are given the same step numbers as the step numbers in FIGS. 3, 5, and 7. FIG. 10A is a diagram showing a temporal change of the pot bottom temperature and the internal temperature in the rice cooking process of the rice cooker according to the fourth embodiment, and FIG. 10B is supplied to the heating coil 12 in the rice cooking process. It is a figure which shows the time change of electric power, and FIG.10(c) is a figure which shows the electricity supply period (water supply period) by the magnet pump 44 in a rice cooking process (steaming process).

Below, the rice cooker which concerns on Embodiment 4 is demonstrated focusing on a steaming process (step S4d). In the rice cooker according to the fourth embodiment, preparations before starting the rice cooking process are the same as those in the first embodiment. When the rice cooker switch of the rice cooker is pressed by the user and the rice cooker starts the rice cook process, first, the preheating process (step S1) is started. When the preheating process ends, the temperature raising process (step S2) and the boiling maintaining process (step S3) are sequentially executed. The preheating process, the temperature raising process, and the boiling maintaining process are the same as those described in any of the first to third embodiments. When the boiling maintaining process ends, the steaming process (step S4d) starts.

When the steaming process (step S4d) starts, the control unit 18 controls the amount of electricity (corresponding to the amount of heating) in the preheating process (step S1) measured by the amount of electricity measuring unit 19 and the rice set in the operation/display unit 42. Based on the amount, the amount of water supplied to the pot-shaped container 1 (water supply amount) is calculated (step S401). The amount of water supply is determined by the temperature of the pan bottom temperature (the detection value of the pan bottom temperature sensor 13) or the internal temperature (the detection value of the internal temperature sensor 43) in the temperature raising step (step S2) as described in the second embodiment. It may be obtained from the rising speed.

Next, the time measuring unit 17 starts measuring the elapsed time from the start of the steaming process (step S402). When the elapsed time from the start of the steaming process is less than the reference time t4 (NO in step S403), the control unit 18 cuts off the power supply to the heating coil 12 (OFF) (step S403), and starts from the steaming process. When the elapsed time is equal to or longer than the reference time t4 (YES in step S404), the heating coil 12 is energized so that the supplied power (corresponding to the heating amount per unit time) becomes the power P6 (step S405).

Next, the control unit 18 determines whether or not the pan bottom temperature is equal to or higher than a preset threshold temperature θh (step S406), and when the pan bottom temperature is equal to or higher than the threshold temperature θh (YES in step S406), the magnet. The pump is energized to supply water for a certain period (step S407), and the heating coil 12 is energized with the power P6 (step S408).

Next, the control unit 18 determines whether or not the pan bottom temperature is lower than a preset threshold temperature θi (step S409), and when the pan bottom temperature is lower than the threshold temperature θi (YES in step S409), supply is performed. The heating coil 12 is energized so that the power is higher than the power P6 (power period P7) (period Q5) (step S410). In the steaming process, the cooked rice in the pan-shaped container 1 has a high adhesiveness between rice grains in a substantially gelatinized state, and the supplied water does not immediately spread to the entire pan-shaped container 1. Therefore, when heating with electric power P7 immediately after the start of water supply, if high-input heating is performed in a state where water has not reached the inner bottom of the pot-shaped container 1, the bottom of the pot-shaped container 1 ( The bottom of the pot) becomes dry and charring occurs. Therefore, it is preferable to start the operation with the electric power P7 after detecting that the entire pot-shaped container 1 has been spread (that is, the temperature of the pot-shaped container 1 has dropped to the temperature θi).

Next, the control unit 18 determines whether or not the pan bottom temperature is equal to or higher than a preset threshold temperature θj (step S411), and when the pan bottom temperature is equal to or higher than the threshold temperature θj (YES in step S411), the heating is performed. The power supplied to the coil 12 is reduced from the power P7 to the power P6 (step S412). When it is determined that the pot bottom temperature is equal to or higher than the preset threshold temperature θj, the reason for lowering the electric power supplied to the heating coil 12 so that the electric power becomes P6 is that if heating is continued at a temperature higher than the temperature θj, charring occurs. This is because when it is detected that the temperature is equal to or higher than the temperature θj, it is possible to prevent burning by heating with the power P6 which is a small power supply.

Next, the control unit 18 determines whether or not the internal temperature detected by the internal temperature sensor 43 is equal to or higher than a preset threshold temperature θk (step S413), and when the internal temperature is equal to or higher than the threshold temperature θk. (YES in step S413), power supply to heating coil 12 is turned off (step S414). As described above, when the internal temperature sensor 43 detects the temperature θk (YES in step S413), the control unit 18 shuts off the power supply to the heating coil 12 (step S414) and proceeds from the start of the steaming step (step S4d). When it is determined that the time is equal to or longer than the reference time t5 (YES in step S415), the steaming process ends and the rice cooking ends.

As described above, according to the rice cooker according to the fourth embodiment, it is possible to prevent drying and burning by determining the timing of increasing the power based on the temperature of the pot-shaped container 1.

In addition, when water is supplied in the steaming process, excess water is likely to remain when cooked, but power P7 that is a high output based on the detection values of the pan bottom temperature sensor 13 and the internal temperature sensor 43, and power P6 that is lower than power P7. Since the timing for ending the heating of (3) is determined, it is possible to perform heating until there is no charring and no excess water remains, and it is possible to suppress deterioration in taste.

<<5>> Modification In the above-described first to fourth embodiments, the structure in which the water in the water tank 31 is supplied into the pan-shaped container 1 has been described, but the water supply method is not limited to this. The rice cookers according to Embodiments 1 to 4 may be provided with a water supply path directly connected to a water tap, instead of the water tank 31.

Further, the control based on the pan bottom temperature in the first to fourth embodiments can be changed to the control based on the internal temperature by the internal temperature sensor 43 or the control based on both the pan bottom temperature and the internal temperature. Further, the control based on the internal temperature in Embodiments 1 to 4 can be changed to the control based on the pan bottom temperature by the pan bottom temperature sensor 13 or the control based on both the pan bottom temperature and the internal temperature.

Further, in the above-described first to fourth embodiments, the case where one pan bottom temperature sensor 13 and one internal temperature sensor 43 are provided has been described, but a plurality of pan bottom temperature sensors and a plurality of internal temperature sensors are provided. It is also possible to perform control based on a plurality of detected values.

Further, in the above-described first to fourth embodiments, the electric rice cooker in which the heating coil 12 as the heating unit heats the pan-shaped container 1 by electromagnetic induction has been described, but the heating method is not limited to this. The heating unit of the rice cooker according to Embodiments 1 to 4 may be a heating unit using an electric heater or a heating unit of another system such as a gas heating unit, instead of the electromagnetic induction.

1 pot-shaped container (rice cooker), 1a flange part, 10 main body, 10bA lid steam port, 10bB lid hole part, 10bC lid water supply port, 11 container cover, 11a hole part, 12 heating coil (heating part), 13 pan bottom temperature Sensor (container temperature sensor), 14 hinge part, 17 time measuring part, 18 control part, 19 energization amount measuring part, 20 lid, 20a outer lid, 20b inner lid, 20bA lid packing, 21 locking material, 22 cartridge, 22a steam inlet, 22b steam outlet, 31 water tank, 32 tank lid, 32a tank ventilation hole, 32b tank water inlet, 32c communication pipe, 41 water supply passage, 41a lid side passage opening, 41b tank side passage opening, 41c passage , 42 operation/display section (operation section), 43 internal temperature sensor (heated object temperature sensor), 44 magnet pump (pump), 44a magnet pump motor, 44b impeller casing, 100 rice cooker (heating cooker).

Claims (9)

A pot-shaped container for containing a heated object,
A heating unit for heating the pot-shaped container,
A water supply unit for supplying water into the pot-shaped container,
A control unit that controls the heating unit and the water supply unit in the rice cooking process;
A rice cooker equipped with
When the control unit causes the water supply unit to supply water during the first step in which the heating amount per unit time by the heating unit is the first heating amount, the control unit supplies the water for the first period immediately after the water supply. The second step in which the heating amount is changed to a second heating amount larger than the first heating amount in at least one of the second period on the way and the third period immediately before the water supply is executed. A rice cooker that controls the heating unit. Further comprising a container temperature sensor for detecting the temperature of the pot-shaped container,
The control unit controls the heating unit to decrease the second heating amount when the temperature detected by the container temperature sensor reaches a predetermined first reference temperature during the second step. The rice cooker according to claim 1, which is controlled. The period of the second step is at least one period of the first period and the second period,
The rice cooker according to claim 2, wherein the first reference temperature is a temperature equal to or higher than a temperature detected by the container temperature sensor immediately before being changed to the second step. Further comprising an internal temperature sensor for detecting the temperature of the object to be heated,
The control unit controls the heating unit to reduce the second heating amount when the temperature detected by the internal temperature sensor reaches a predetermined second reference temperature during the second step. The rice cooker according to claim 1, which is controlled. The rice cooking step is a step immediately after the rice cooking step is started, and includes a preheating step of preheating the object to be heated,
The control unit controls the heating unit so as to execute the second step in the first period when water is supplied to the water supply section during the preheating step. Rice cooker described in. The rice cooking step includes a heating step of heating the pan-shaped container until the object to be heated boils,
The control unit controls the heating unit so as to execute the second step in the third period when water is supplied to the water supply section during the temperature raising step. Rice cooker described in paragraph. The rice cooking step includes a boiling maintaining step of maintaining boiling of the object to be heated after boiling,
The control unit controls the heating unit to execute the second step in the second period and the first period when water is supplied to the water supply unit during the boiling maintaining step. The rice cooker according to any one of 6 above. The rice cooking step includes a steaming step of steaming the heated object next to a boiling maintaining step of maintaining boiling of the heated object,
The said control part controls the said heating part to perform the said 2nd process in the said 2nd period and the said 1st period, when making the said water supply part supply water during the said steaming process. The rice cooker according to any one of 1. The said control part controls the said heating part by adjusting at least one of the electric power per unit time supplied to the said heating part and the said electric power supply to the said heating part. Rice cooker described in paragraph.

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