JP2002142979A - Rice cooker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of obtaining fluffy cooked rice with limited uneven cooking regardless of the mount of rice to be cooked by eliminating uneven temperature inside an inner rice cooking pot depending on the amount of the rice to be cooked in a rice cooker with a driver for driving the inner pot. SOLUTION: In the rice cooker having a driver 6 for oscillating the inner rice cooking pot 2, the amount of rice to be cooked is determined at an early stage of the rice cooking process from a load of the driver and a temperature rising characteristic of the inner pot to adjust whether or not to drive with the driver 6, the driving time zone, the degree of driving, the timing of controlling a heater 3 and the driver 6 and the like.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rice cooker provided with a driving device for driving a rice cooking pot.

[0002]

2. Description of the Related Art As disclosed in Japanese Patent Application Laid-Open No. 6-225832, a conventional rice cooker can be detachably housed in a main body and includes a heating means and a rotation means of an inner pot which is heated while rotating. It is controlled by the amount of cooked rice. In this control, the amount of cooked rice is detected by a weight sensor on the rotating shaft, and rotation of the inner cooker is stopped based on the temperature of the inner cooker set based on the amount of cooked rice.
By this control, excessive rotation is prevented, and at the same time, the shape and irregularity of rice grains during rice cooking are reduced to improve rice cooking performance.

[0003]

In a conventional rice cooker, a rotating means is provided in the inner pot to reduce uneven heating of the inner pot, thereby improving the rice cooking performance. The stirring movement of water or cooked rice cannot be promoted, and uneven cooking in the depth direction of cooked rice cannot be sufficiently improved.

[0004] Further, in the structure in which the rotating means and the weight sensor are arranged on the rotating shaft, the size of the main body is increased, and
A malfunction due to heat of the induction heating coil is likely to occur.

Further, since only the weight sensor for detecting the amount of cooked rice has a structure that supports the inner pot, a large force is concentrated on the weight sensor, and correction of the means for detecting the amount of cooked rice due to variation in the storage position of the inner pot cannot be performed. . Similarly, it is not possible to correct the rice cooking amount detecting means due to variations in the contact state such as the position of the inner pot of the inner pot seal and the deterioration of the seal.

The present invention has been made to solve at least one of the above problems.

[0007]

The above object can be achieved by a rice cooker in which the amount of cooked rice is detected in advance at the initial stage of rice cooking, and the amount of cooked rice is controlled according to the amount of cooked rice. You.

That is, in a rice cooker provided with a driving device for driving the rice cooking pot, the amount of rice at the time of rice cooking is reduced by, for example, the driving device load such as power consumption and current value, and the heating of the rice cooking pot at the start of heating. This can be solved by grasping from the characteristics at an early stage of the rice cooking process and controlling whether or not the driving mechanism is driven, a driving time zone, a driving amount, and a control timing of the heating device and the driving device. In addition, the amount of cooked rice can also be determined from, for example, force, pressure, distortion, etc. applied to the shaft supporting the inner pot.

[0009]

FIG. 1 is a sectional view of a rice cooker according to an embodiment of the present invention, and FIG. 2 is a block diagram thereof. In the illustrated rice cooker, a rice cooker main body 1, an inner pan 2 housed in the main body 1, a heating device 3 for heating the inner pan 2, a control device 4 for controlling the output of the heating section, Lid 5 covering the upper part
And a drive device 6 provided on the main body 1 and the like.

A temperature detecting device 3c capable of detecting the temperature of the inner pan 2 is attached to the main body 1 at a structure connected to an elastic body 3b such as a spring or rubber. Here, the temperature detection device 3c
Can be constituted by, for example, a contact thermometer such as a thermistor or a thermocouple, or a non-contact thermometer such as an infrared ray.

The inner pan 2 has an outer layer made of, for example, stainless steel, which is an electromagnetic material, and an inner layer made of, for example, aluminum, which is a material having a high thermal conductivity. I have.

The inner pot 2 is structured to be held by a jaw 71 of the storage part 7 and a jaw 21 provided on the inner pot 2, and the storage part 7 has an elastic material such as rubber. Is provided, and the positional deviation when the inner pot 2 is stored is corrected.

The storage section 7 is held by a fulcrum 8 provided on the horizontal center axis of the inner pan 2.
The inclined position at which it is arranged is determined by the drive fulcrum 6c of the drive device 6 provided at the bottom of the storage section. Drive fulcrum 6c
Is moved by a reciprocating motion of a support rod 6b connected by a sliding structure. Here, the position of the driving fulcrum 6c is
Anywhere on the outer wall of the building.

The fulcrum 8 is formed by connecting the main body 1 and the side surface of the storage section 7 with a cylinder, and the cylinder is fixed to the main body 1 or the storage section 7 and performs a sliding motion on the shaft circumference on one side. Will be Here, the column may be formed of a metal such as aluminum or the same material as the main body 1. Further, in the present embodiment, a force detection unit 81 that can detect, for example, force, pressure, torque, and the like is installed at the fulcrum 8 and, for example, the object to be heated 10
May be detected.

The support rod 6b is connected to a drive source 6a such as a motor provided in the drive device 6 so as to be eccentric with respect to the rotation axis. The rotation of the drive source 6a causes the support rod 6b to reciprocate roughly. I can exercise. The support rod 6b
The drive fulcrum 6c connected to the support bar 6b is pushed by the reciprocation of the inner pan 2 and the inner pan 2 repeats a pendulum-like swinging reciprocating motion about the fulcrum 8 as a central axis.

Here, the drive source 6a may be one that performs reciprocating motion electrically or magnetically. Further, in the present embodiment, a load detecting device 65 capable of detecting the load of the driving source 6a, for example, electric power and current, is provided in the vicinity of the driving source, so that a load variation due to the weight of the object 10 can be detected.

Here, it has been confirmed by experiments that the reciprocating motion amount is preferably in the range of about 5 to 20 mm and the cycle is in the range of 0.5 to 1.5 Hz.

The lid 5 is provided with an elastic body 51 such as rubber and a heat radiating plate 52 for sealing at a portion in contact with the upper portion of the inner pot 2, so that the inner pot 2 moves even if the inner pot 2 moves. It has a structure that keeps the airtightness.

In this embodiment, an elastic body 53 such as a spring is further provided inside the lid to follow the large movement of the inner pot 2 and to maintain the airtightness in the inner pot 2. .

Further, a heater 55 is provided on the heat radiating plate 52 inside the lid, so that the inner pot 2 can be heated from the upper surface.

On the other hand, the heating device 3 disposed below the inner pot 2 includes an induction heating coil 3a formed in a spiral shape and a rod-shaped ferrite 3d radially installed below the induction heating coil.
And so on. When energization of the heating device 3 is started,
A current flows through the induction heating coil 3a, and a magnetic field is generated at the bottom of the inner pot by the induction heating coil 3a and the ferrite 3d.
Due to the magnetic field, an eddy current flows in the outer stainless steel layer corresponding to the upper part of the ferrite, resulting in heat loss and heat generation. This heat is conducted to the inner aluminum layer of the inner pot, thereby heating and heating an object to be heated, for example, rice or water, inside the inner pot. Efficiency, large heat generation can be realized.

Here, in this embodiment, the heating device 3 is disposed only below the inner pot 2, but a similar heating device or other heating means is disposed on the side surface of the inner pot 2 other than below, inside the lid 5, and the like. The structure may be modified. Further, the heating device 3 may be a heating source mainly including a gas, an electric heater, and the like. Note that the heaters provided below and on the side surfaces are not integrated, but may be divided into a plurality of pieces and the heating may be controlled separately.

The heating device 3 swings together with the inner pot 2 and the storage section 7 so that the arrangement distance thereof can be kept constant with respect to the movement of the inner pot 2.

The cooking of the object to be heated 10 in the inner pan 2 is controlled to a target temperature by a control unit 4 provided inside the main body 1 based on the temperature data detected by the temperature detecting device 3c.

At the time of cooking, the display unit 41 may display the heating status of the heating device 3 and the exercise status of the inner pot 2 by the driving device 6.

With the above structure, control as shown in the block diagram of FIG. 2 becomes possible. That is, the control device 4 can manually set the information at the time of cooking and obtain at least one information of the temperature detection device 3c, the load detection device 65, or the force detection device 81, and the driving device 6,
And one or more of the heating device 3 and the display unit 41 are controlled.

Hereinafter, an example of the operation of the present embodiment having the above configuration will be described with reference to the flowchart shown in FIG. 3 (step S1).
To S11).

For example, washed rice and water are put into the inner pot 2 as the object to be heated 10, the inner pot 2 is stored in the main body 1, and the inner pot 2 is covered with the lid 5. When the cooking of the object to be heated 10 (rice cooking) is started, a current is supplied from the control device 4 to the induction heating coil 3a of the heating unit. At this time, in the inner pan 2, a magnetic field is generated near the bottom, an eddy current flows in the stainless steel layer of the inner pan 2, and heat is lost, and the stainless steel generates heat. And heat the rice and water inside the inner pot (S1).

In the drive device 6, when the rice cooker starts, the drive source 6a built in the main body 1 starts to rotate, and the support rod 6c eccentrically connected to the motor shaft reciprocates in conjunction. The inner pan 2 starts a swinging movement about the fulcrum 8 by a reciprocating motion of the driving fulcrum that moves together with the support rod 6c (S2).

Next, determination of the amount of cooked rice Ge is performed (S
3). The determination of the amount of cooked rice uses information obtained by the temperature detection device 3c, the force detection device 81, or the load detection device 65. For example, in the temperature detecting device 3c, FIG.
The amount of cooked rice is determined using the difference in the temperature rise curve caused by the amount of cooked rice shown in FIG. FIG. 4 shows that, depending on the amount of rice cooked, the temperature rise value after the start of rice cooking t hours increases as the amount of cooked rice decreases (T1> T0). That is,
By detecting the temperature or the temperature gradient after the time t from the start of heating, the amount of rice in the inner pot can be determined. In the rice cooking method shown in the present embodiment, it has been experimentally confirmed that the time zone in which the uniformization of the temperature by the movement of the inner pot 2 works most effectively is from before the end of preheating until the water runs out.

On the other hand, for example, in order to determine the amount of cooked rice by the force detecting device 81, the force applied to the fulcrum 8, which increases in accordance with the amount of cooked rice, for example, the torque or strain of the fulcrum shaft may be sensed. Further, for example, in order to determine the amount of cooked rice by the load detection device 65, the load m of the drive source 6a, for example, the power consumption and the current value, which increases according to the amount of cooked rice, may be sensed. Therefore, the detection value P based on any one of the information or the combination of the plurality of information of the detection method of the structure of the present embodiment is obtained.
Thus, the amount of cooked rice can be accurately determined. That is, the amount of cooked rice Ge
Is represented by a function f (P) obtained from the detection value P (S3).

Thereafter, the swing of the inner pot 2 is stopped (S4), and the amount of cooked rice Ge and the amount of required rice C for swing are compared (S5). Under the condition that the amount of cooked rice is small, it is not necessary to swing, and the whole can be cooked without unevenness only by the heating power of the heating device 3. Here, the required amount of rocking rice C to be rocked is, for example, 20 to 40% of the rated rice cooking amount determined by the rice cooker, or the rice loading height from the bottom of the inner pan 20 to 40 mm.

In the case of Ge <C, it is possible to obtain a sufficiently delicious cooked rice without shaking the inner pot 2, so that
The heater control may be performed at the rice cooking temperature Te that matches the rice cooking amount. That is, the cooked rice temperature Te is determined by the amount of cooked rice Ge and its temperature T.
It is represented by a function f (T, Ge) obtained by the time change of e, and cooking is performed by performing feedback control of the rice cooking process (S10). Thereafter, the current supply to the heating device is stopped (S11), and the cooking ends.

On the other hand, in the case of Ge> C, in order to obtain delicious cooked rice, a stirring action by swinging the inner pot 2 is required. In order to give the inner pot 2 a rocking motion in the most effective time zone, the control is shown with the rice temperature Te set at a set temperature (S6). That is, the rocking movement start temperature is the rice cooking temperature Te.
And a function gs (Ge) determined by the amount of cooked rice. Here, the rocking motion start temperature is desirably in the range of 50 to 60 ° C.

When the cooked rice temperature Te becomes higher than gs (Ge), the swinging of the inner pot 2 is started (S7). The rice and water 10 inside the inner pot 2 are given a three-dimensional force in the inner pot by the swinging motion of the inner pot 2. In the inner pot, the movement of rice and water is forcibly performed, thereby promoting the stirring and mixing actions of the rice and water inside. In the present operation, the heat transfer coefficient between the inner pot 2 and the water is improved, and the heat from the heating device 3 can be efficiently transmitted to the water and the rice. As a result, it is possible to easily shorten the cooking time and save energy.

The rice cooking proceeds, and the swing stop temperature of the inner pot 2 is determined. The stop temperature is controlled by detecting a temperature Td at the time of dryout due to a decrease in moisture in the inner pot with the temperature detecting device 3c (S8). That is, the rocking motion of the inner pot 2 is stopped by comparison with the dryout temperature Td. Here, the stop of the rocking motion may be controlled by a timer based on the time after the rocking start or the time after the dryout set for the amount of cooked rice.
By the step S8, the swinging motion of the inner pot 2 is stopped (S9), and the heating is stopped when the cooking is completed (S9).
11).

Here, in the present flowchart, the control is performed during the most effective exercise time period shown in FIG. 4, but the drive may be always performed during the process from the start to the end of rice cooking.
Here, it has been confirmed by an experiment that the power consumption due to the swing is smaller than that of the whole rice cooker by 3% or less.

Next, another flowchart (steps S12 to S17) up to the determination of the amount of cooked rice in another embodiment of the present invention shown in FIGS. 5 to 7 will be described. For cooking rice, the washed rice and water are put into the inner pot 2 as in FIG. 3, the inner pot 2 is stored in the main body 1, and the inner pot 2 is covered with the lid 5. In FIG. 5, when starting the rice cooking, for example, the rice cooking process such as whether or not to perform the swinging motion of the inner pot 2 is manually set in advance on the display unit 41 (S12) regardless of the specification. You can choose the cooking method. In FIG. 6, when the inner pot 2 is stored, for example, a force, a pressure, a distortion, or the like acting on the cylinder serving as the fulcrum 8 of the storage unit 7 is detected by a force detection device 81 such as a distortion sensor. The rice cooking amount Ge can be determined (S14). That is, the amount of cooked rice Ge is defined by a function of the value F obtained by the force detection device 81, so that an accurate amount of cooked rice can be grasped. In FIG. 7, the temperature change immediately after the start of rice cooking is detected by the temperature detection device 3c, and the amount of cooked rice can be determined from the temperature gradient as described in FIG. 3 (S1).
6). The detection, grasp and control of the amount of cooked rice described in FIGS. 5 to 7 can be more accurately determined by a combination of two or more cooked rice, so that delicious rice can be provided.

Next, a flowchart after the determination of the amount of cooked rice in another embodiment of the present invention shown in FIG. 8 (step S18)
To S21) will be described. In FIG. 8, for example, after the rice cooking amount Ge is determined according to the flowchart of FIG. 7, it is determined whether or not the rocking motion of the inner pot 2 is performed based on the rice cooking amount. If the amount of cooked rice is large, sufficient heat cannot be obtained for the amount of cooked rice,
Since uneven cooking is likely to occur, the limit of the amount of cooked rice C and the Ge
Are compared to determine the presence or absence of swing (S18). If the amount of cooked rice is small, the control of the heating device is directly performed according to the amount of cooked rice, and the cooking of the cooked rice is completed and the heating is stopped (S2).
1). When the amount of cooked rice is large, the swing motion of the inner pot 2 is performed by the driving device 6 (S19), the motion is continued until the cooking of the cooked rice is completed, and the heating is also stopped following the stop of the swing motion (S20). (S21). By judging the presence or absence of such a swing, it is possible to perform rice cooking that is both delicious and energy-saving.

Next, another flowchart after the determination of the amount of cooked rice in another embodiment of the present invention shown in FIG.
21 to S24) will be described. In FIG. 9, the timing of starting and stopping the swing of the inner pot 2 is performed based on the temperature detected by the temperature detecting device 3c. The discriminants in steps S22 and S24 in FIG. 9 are the same as those in steps S6 and S8 in FIG. In this flowchart, the effective swinging motion time range shown in FIG. 4 can be set for each rice cooked amount only by the temperature detection device 3c. As described above, it is possible to cook delicious rice with low power consumption without increasing rice cooker unevenness due to an increase in the amount of cooked rice.

[0041]

According to the present invention, it is possible to provide a rice cooker that can cook delicious rice with less uneven cooking and can save energy with low power consumption regardless of the amount of cooked rice.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of Embodiment 1 of the present invention.

FIG. 2 is a block diagram of the embodiment of FIG.

FIG. 3 is a flowchart showing a first operation example of the present invention.

FIG. 4 is a diagram showing a change in temperature of an object to be heated in a conventional rice cooker.

FIG. 5 is a flowchart showing an operation example up to the determination of the amount of cooked rice according to the present invention.

FIG. 6 is another flowchart showing an operation example up to the determination of the amount of cooked rice according to the present invention.

FIG. 7 is another flowchart showing an operation example up to the determination of the amount of cooked rice according to the present invention.

FIG. 8 is a flowchart showing an operation example after determining the amount of cooked rice according to the present invention.

FIG. 9 is another flowchart showing an operation example after the determination of the amount of cooked rice according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main body 2 Inner pan 3 Heating device 4 Control device 5 Lid 6 Drive device 7 Storage part 8 Support point 9 Code reel 10 Object to be heated 41 Display part 65 Load detecting device 81 Force detecting device

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4B055 AA03 BA63 CA10 CA68 CD02 CD58 DB14 GB06 GB18 GC40 GD02 GD05

Claims (2)

[Claims] An inner pot (2) housed in a main body (1),
A heating device (3) for heating the inner pot (2), a temperature detector (3c) for detecting the temperature of the inner pot (2), and a driving device (6) for driving the inner pot (2). And a control device (4) for controlling the heating device (3) and the drive device (6), and the control device (4) controls the load power or load torque of the drive device (6) and the temperature detection device (3c). ), The rice cooker determined from at least one detected value of the temperature of the inner pot (2) or the force detected by the force detecting device (81) provided in the holding portion of the inner pot (2). Whether the driving device (6) is driven based on the amount of rice, the driving device (6)
And a rice cooker for controlling the output time change of the heating device (3) or the operation timing of the driving device (6). 2. An inner pot (2) stored in the main body (1),
A heating device (3) for heating the inner pot (2), a temperature detector (3c) for detecting the temperature of the inner pot (2), and a driving device (6) for driving the inner pot (2). And a control device (4) for controlling the heating device (3) and the driving device (6), wherein whether or not the driving device (6) is driven can be manually set in advance. vessel.