JP3185743B2 - Electric rice cooker - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric rice cooker, and more particularly to an electric rice cooker in which delicious rice can be obtained by rapidly cooling rice after cooking.

[0002]

2. Description of the Related Art Generally, in an electric rice cooker, rice and water are contained in an inner pot, and the inner pot is heated by a heating means (for example, an electromagnetic induction coil or an electric heater) in accordance with predetermined rice cooking characteristics. To cook rice.

[0003] The rice cooked as described above contains 1
It is a high temperature near 00 ° C, and it takes 1 to
It takes 2 hours. Therefore, the rice is exposed to high temperature for a long time, during which time the deterioration (discoloration) of the rice due to oxidation and browning is promoted, and the decomposition of fatty acids contained in the rice is promoted by the oxygen reaction, resulting in an unpleasant odor. And other problems arise.

[0004] The above browning reaction and fatty acid decomposition reaction are particularly likely to occur when the temperature of rice is in the temperature range of 80 to 85 ° C. Electric rice cookers designed to cool rapidly have been developed.

[0005] For example, as disclosed in Japanese Patent Application Laid-Open No. 9-154718, a fan in which a blower fan is disposed in a gap between an inner surface of a rice cooker main body and an outer surface of a heat shield plate has been proposed. I have.

[0006]

However, in the above-mentioned known example, the cooling air blown from the blower fan can remove hot air trapped in the gap between the rice cooker main body and the heat shield plate. However, since the inner pot is not directly cooled, the rice may be insufficiently cooled.

Further, in the above-mentioned known example, there is also disclosed an embodiment in which a large number of holes are formed in the heat shield plate so that the air from the blower fan is supplied between the inner pan and the heat shield plate. However, in this case, since holes are formed in the heat shield plate, there is a possibility that foreign matter (for example, water or rice grains) may enter the inside of the rice cooker main body.

[0008] The present invention has been made in view of the above points, and aims to cool rice after the completion of rice cooking and to eliminate the possibility of foreign matter entering the rice cooker main body. It is.

[0009]

According to the basic configuration of the present invention (the invention of claim 1), as a means for solving the above-mentioned problems, a container main body configured to accommodate an inner pot therein, A cover body for opening and closing the opening of the container body,
Heating means for heating the inner pan , wherein the container body
A sensor for detecting the temperature of the inner pan through the inner bottom.
In the electric rice cooker and formed by arranging a Tasensa, the space in the side portion in the container body, together with arranging the blower fan, the blower from air blowing fan, air blowing off
And one end of the duct is connected to the other end of the duct.
Shoulder member forming an open edge of the container body to be continued
And an annular passage formed on an inner wall of the annular passage.
Can be supplied to the upper part of the gap formed between the stored inner pot and the container body through a ventilation passage formed of
It is configured so that:

[0010] With the above configuration, when the blower fan is started to drive after the rice cooking, the blown air from the blower fan communicates with the inner pot and the container body through the blower passage including the duct, the annular passage and the communication port. Is supplied to the upper portion of the gap between the inner pan and the inner pan is directly cooled by the blowing. Therefore, the rice is rapidly cooled after the completion of the rice cooking, and the rice can quickly pass through a high-temperature zone of about 85 ° C. to 80 ° C. from around 100 ° C. where the rice is most deteriorated. Also blower fan
From the inner pan and the container body
Is supplied to the upper part of the
The blown air moves warmer as it moves down the gap.
The center sensor sends
It is hard to be affected by wind,
I can do it for sure. In addition, the air passage, air blowing off
And one end of the duct is connected to the other end of the duct.
Shoulder member forming an opening edge of the container body to be continued
And an annular passage formed on an inner wall of the annular passage.
The airflow fan is
The air passage leading to the gap is a closed passage,
As a result, there is no danger of foreign matter (eg, water, rice grains, etc.) entering the container body. In addition, the inner peripheral surface of the container body and the inner pot
The air supplied to the gap between
And then discharged from the gap between the inner pot and the rim of the container body
Is done.

[0011]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

As shown in FIG. 1, this electric rice cooker has a double-structured container body 1 having a space 4 and configured to accommodate an inner pot 3 for cooking rice therein, and the container body. 1
And a cover 2 for opening and closing the upper opening.

The container body 1 has a body 5a serving as an outer wall.
An outer case 5 made of a synthetic resin (for example, polypropylene) integrally having a bottom portion 5b serving as a bottom wall, and a bottomed cylindrical protective frame 6 made of a synthetic resin (for example, polypropylene) serving as an inner peripheral wall. And the shoulder member 7 made of a synthetic resin (for example, made of polypropylene) for coupling the upper end of the protective frame 6 and the upper end of the outer case 5 to each other.
The space 4 is formed by being surrounded by the outer case 5, the protective frame 6 and the shoulder member 7. The inner pan 3 is housed in the protective frame 6 so as to be able to be taken out.

At the center of the bottom of the inner pot 3, an upwardly projecting raised portion 3a is formed. The raised portion 3a generates an internal convection above the raised portion 3a in addition to the external convection along the side wall at the time of cooking rice, and the temperature in the inner pot 3 is formed by the formation of the internal convection and the external convection. Can be made uniform.

A raised portion 6a is also formed at the center of the bottom surface of the protective frame 6 along the inner pot raised portion 3a, and a center sensor 8 serving as a temperature detecting means is provided at the center. There is formed a sensor hole 9 for shifting. In this case, even if water or the like enters the protection frame 6, the sensor hole 9 is opened above the bottom surface, and therefore leaks downward (that is, into the space 4 of the container body 1). Disappears.

An annular electromagnetic induction coil (hereinafter referred to as a rice cooking work coil) 10 acting as a heating means during rice cooking so as to surround the sensor hole 9 is provided on the bottom surface of the protective frame 6 and on the side peripheral surface from the bottom surface. It is arranged in the curved portion between the two. The rice cooker coil 10 generates an alternating magnetic field, generates an eddy current as an induced current in the inner pot 3 by the electromagnetic induction of the alternating magnetic field, and heats using the resistance heat of the eddy current. It is supposed to. In addition,
The inner pot 3 is made of a material (for example, a magnetic material) that can generate an eddy current by the cooker work coil 10.

The rice cooking work coil 10 is sandwiched between a coil die 11 fixed to the bottom surface of the protection frame 6 and the bottom surface of the protection frame 6. Reference numeral 12 denotes a ferrite core, which has a function of blocking so that the magnetism of the work coil 10 for rice cooking does not affect equipment located below.

A center sensor 8 is provided in the sensor hole 9 so as to contact the bottom of the inner pot 3. Further, an annular electromagnetic induction coil (hereinafter, referred to as a heat retaining work coil) 13 that acts as a heating means at the time of keeping the temperature is attached to a side peripheral surface of the protective frame 6.

The bottom of the container body 1 (ie, the outer case 5)
The bottom 5b) is provided with a power transistor for controlling the energization of the rice cooking and warming work coils 10, 13 and a cooling fan 14 for forcing cooling air to a rectifying diode bridge (not shown). I have. Also,
The bottom wall of the container body 1 (specifically, the bottom 5 b of the outer case 5) has an air inlet 1 facing the blower fan 14.
5 are formed.

On the other hand, the lid 2 has an upper plate 16 made of synthetic resin (for example, made of polypropylene) constituting the outer surface and an annular lower plate made of synthetic resin (made of, for example, polypropylene) constituting the inner peripheral surface. 17 and a metal radiator plate 18 attached to the inner peripheral edge of the lower plate 17. A space 19 surrounded by the upper and lower plates 16, 17 and the radiator plate 18 has a heat insulating material 20. Are arranged.

The lid 2 is attached to a hinge receiver 21 formed on one side of the shoulder member 7 via a hinge pin 22 so as to be pivotable and detachable.

At the center of the lid 2, there is formed a tubular portion 23 suspended from the upper plate 16, and the inside of the tubular portion 23 discharges steam generated during rice cooking to the outside. Cap 25 having a steam discharge passage 24 for the
Is detachably attached. In the steam cap 25, a ball valve 26 acting as a pressure regulating valve is provided. At the lower end of the steam cap 25, an inner lid 27 for closing an opening of the inner pot 3 is attached. 28 is a steam inlet to the steam cap 25, 29 is a steam outlet from the steam cap 25, 30
Are the periphery of the inner lid 27, the opening of the inner pot 3 and the lid lower plate 17;
This is a seal packing that seals between the two.

The inner peripheral edge of the heat radiating plate 18 is
The outer peripheral edge of the heat radiating plate 18 is coupled to the inner peripheral edge of the lower plate 17. A lid heater 3 is provided on the upper surface of the heat radiating plate 18 for heating the heat radiating plate 18 to prevent dew and growth of oneva.
1 is attached.

In this embodiment, a blower fan 33 is attached to the shoulder member 7 by screws 34 in a space 4 in a side portion (for example, the hinge receiver 21 side) in the container body 1. It is arranged in a mounted state (see FIG. 2). As shown in FIG. 2, the blower fan 33 is a centrifugal fan including a multi-blade rotor 36 driven to rotate by a fan motor 35 and a scroll-type fan casing 37 surrounding the multi-blade rotor 36. In this case, the space 4 in the container body 1 (particularly, the space on the hinge receiver 21 side where a large surplus space is formed).
The container body 1 can be used effectively.
It is no longer necessary to increase the vertical dimension of the.

The discharge port 37a of the fan casing 37
Is connected to an inlet 3 of an annular passage 39 formed in the shoulder member 7.
9a. The shoulder member 7 has a plurality of communication ports 40 that communicate the annular passage 39 with an upper portion of an annular gap S formed between the inner pot 3 and the protection frame 6. The communication ports 40 are formed at equal intervals in the circumferential direction of the shoulder member 7. That is, the blast W from the blast fan 33 is supplied to the duct 38 and the annular passage 39.
The air is supplied to the upper portion of the gap S through the air passage A including the communication port 40. Reference numeral 58 is an air intake.

In the space 4 on the side opposite to the hinge of the container body 1 (ie, on the side provided with the lock mechanism 41 for locking the lid 2), the work coils 10 and 13 for rice cooking and heat insulation and the lid heater are provided. A control board 42 in which a control unit for controlling power supply to the power supply 31 and the like is incorporated is provided. The control board 42 includes various switches (for example, a rice cooker switch, a reservation switch, a warming switch, and the like) and a liquid crystal display device ( (Not shown) is provided.

Next, an electric configuration of the electric rice cooker according to the present embodiment will be described based on an electric circuit diagram shown in FIG. Parts corresponding to those shown in FIGS. 1 and 2 are denoted by the same reference numerals.

The electric power from the commercial AC power supply 43 passes through a temperature fuse 44 and a rectifier circuit 45 that detects and abnormally heats the inner pot 3 and blows it out.
0,13. Reference numeral 46 is a smoothing capacitor, and 47 and 48 are resonance capacitors.

The above-mentioned rice cooker and heat insulating work coil 1
Microcomputer units (hereinafter, referred to as 0 and 13)
IGBT drive circuit 5 from 49)
Control signals are supplied from power transistors 52 and 53 which are ON / OFF controlled by commands passed through 0 and 51, respectively.

The microcomputer 49 controls the power transistors 52 and 53 according to a predetermined program, thereby controlling the energization of the work coils 10 and 13, the lid heater 31, the cooling fan 14 and the blower fan 33. This energization control is performed based on an output signal output from the thermistor 54 incorporated in the center sensor 8 via the temperature sensor detection circuit 55.

In FIG. 3, reference numeral 56 denotes a group of various switches (for example, a rice cooker switch, a reservation switch, a warming switch, etc.), and 57 denotes a liquid crystal display.

Next, with reference to a flowchart shown in FIG. 4 and a time chart shown in FIG. 5, the control of the blower fan in the electric rice cooker having the above-described configuration will be described in detail.

If it is determined in step S ₁ that the rice cooking has been completed (that is, the steaming process has been completed), the inner pot 3 detected by the center sensor 8 in step S ₂ .
The temperature T of the input, the blower fan 33 in step S ₃ is driven initiated by applying voltage 12V. In addition,
At this time, the energization to the rice cooker coil 10, the warming work coil 13, and the cooling fan 14 is stopped, and the energization to the lid heater 31 is continued.

[0034] Next, comparison with the 90 ° C. a preset temperature and the inner pot T in step S ₄ is performed, wherein until it is determined that T <90 ° C., the blower fan 33 is 1
While being continuously driven at 2V, when it is determined that T <90 ° C., the process proceeds to step S _5, the blowing fan 33 is driven by applying voltage 6V.

[0035] The comparison between 82 ° C. a preset temperature and the inner pot T in step S ₆ is performed, wherein until it is determined that T <82 ° C., the blower fan 33 6
While being continuously driven at V, if it is determined that T <82 ° C., the process proceeds to step S _7, with the energization of the blower fan 33 is stopped (i.e., drive stop), Step S ₈
Then, the power supply to the lid heater 31 is also stopped. The reason for performing the above-described blowing fan control is that the inner pot temperature immediately after the end of rice cooking is as high as around 100 ° C., so that the blowing fan 33 is initially cooled to 90 ° C. by driving at a high speed of 12 V, Thereafter, driving at 6V saves power consumption. In addition, the blower fan 33 is used from the end of cooking rice until the temperature of the inner pot drops to 82 ° C.
May be driven with the same output.

[0036] Thereafter, until 72 ° C. is a preset temperature and the inner pot T in step S ₉ (i.e., retained temperature) compared with is made, the decision is T <72 ° C. and,
The power supply to the lid heater 31 is stopped, but T <72 ° C.
If it is determined that, the process proceeds to step S _10, with energization of the lid heater 31 is started, the temperature-maintaining work coil 13
Is performed.

As described above, by starting to drive the blower fan 33 after the rice cooking is completed, the blown air W from the blower fan 33 is supplied to the gap S between the inner pot 3 and the container body 1 through the blow passage A. The inner pan 3 is directly cooled by the air W. Therefore, the rice is cooled until the inner pot temperature reaches 82 ° C. after the completion of the rice cooking, and the rice is cooled from around 100 ° C. to 85 ° C.
It can quickly pass through a high temperature zone of 80 ° C. After that, the temperature is cooled to 72 ° C., which is the heat retention temperature, by natural cooling, and the heat retention control is performed, so that the rice can be kept in a good condition. Further, the temperature of the blast W supplied to the gap S increases as the blast W moves down the gap S, so that the center sensor 8 is less likely to be affected by the blast W. I can do it. In addition, between the inner peripheral surface of the container body 1 and the inner pot 3
The air blown W supplied to the gap S is downward due to a difference in specific gravity.
After moving, it is discharged from the gap between the inner pot 3 and the edge of the container body 1.
Will be issued.

Further, in the case of the present embodiment, since the blower fan 33 is mounted on the shoulder member 7, a special member for mounting the blower fan 33 is not required.

Further , one end of the blowing passage is connected to the blowing fan.
To connect the connected duct and the other end of the duct
Formed on a shoulder member forming an opening edge of the container body
An annular passage and a communication port formed in an inner wall of the annular passage.
Therefore, since it is configured, the air
The air passage becomes a closed passage, and foreign matter (for example,
Water, rice grains, etc.).

A part of the air passage A is constituted by an annular passage 39 formed in the shoulder member 7, and a plurality of the passages A communicate with the shoulder member 7 between the annular passage 39 and the upper part of the gap S. Since the communication port 40 is formed, a ventilation passage structure using the shoulder member 7 is provided, so that a special member for forming the passage is not required.

In each of the above embodiments, the work coil is used as the heating means. However, it is needless to say that the present invention can be applied to an apparatus using an electric heater as the heating means.

[0042]

According to the invention of the present application (the invention of claim 1),
A container body configured to be able to store the inner pot inside,
A lid body for opening and closing the opening of the container body, and heating means for heating the inner pan, and an inner bottom portion of the container body;
Through the center to detect the temperature of the inner pan
In an electric rice cooker provided with a sir , a blower fan is arranged in a space in a side portion in the container body, and blown air from the blower fan is sent to the blower fan.
One end of the duct is connected, and the other end of the duct is connected
Formed on the shoulder member forming the opening edge of the container body
And a communication formed on the inner wall of the annular passage
And it can be supplied to the upper portion of the gap formed between the inner pot and the container body via the air passage comprising a mouth, which is supplied to the upper portion of the gap from the blower fan after cooking completion <br/> Because the inner pot is directly cooled by air blowing, the rice is rapidly cooled after cooking, and it is possible to quickly pass through the high temperature zone of 85 to 80 ° C from around 100 ° C where rice deterioration is most severe. effective.

Further , the air blow from the blower fan is supplied to the inner pot and the volume.
So that it can be supplied to the upper part of the gap formed between the
The air supplied to the gap causes the gap to
As the temperature rises as it moves downward,
From the moment, the center sensor is less affected by airflow
Ri, when the subsequent heat preservation thermostat can be correctly
There is also an effect.

Further, a ventilation passage is connected to the ventilation fan at one end.
And the other end of the duct should be connected.
Formed on a shoulder member forming an opening edge of the container body.
Annular passage, and a communication port formed in the inner wall of the annular passage.
From the blower fan to the gap
The ventilation passage becomes a closed passage, and there is also an effect that there is no possibility that foreign matter (for example, water, rice grains, or the like) enters the inside of the container body through the ventilation passage .

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an electric rice cooker according to an embodiment of the present invention.

FIG. 2 is an enlarged perspective view of a main part of the electric rice cooker according to the embodiment of the present invention.

FIG. 3 is a connection diagram of a control circuit unit in the electric rice cooker according to the embodiment of the present invention.

FIG. 4 is a flowchart of a blower fan control in the electric rice cooker according to the embodiment of the present invention.

FIG. 5 is a time chart of a blower fan control in the electric rice cooker according to the embodiment of the present invention.

[Explanation of symbols]

1 is a container body, 2 is a lid, 3 is an inner pot, 4 is a space, 7 is a shoulder member, 14 is a cooling fan, 33 is a blower fan, 38 is a duct, 39 is an annular passage, 39a is an inlet, 40 is Communication port, 60, 61, 64 are through holes, 65 is a connection duct, A
Is a ventilation passage, S is a gap, and W is a ventilation.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) A47J 27/00

Claims (1)

(57) [Claims] 1. A container main body configured to accommodate an inner pan therein, a lid body for opening and closing an opening of the container main body, and heating means for heating the inner pan , Content
Penetrates the inner bottom of the container body to detect the temperature of the inner pan
An electric rice cooker provided with a center sensor for air blowers, wherein a blower fan is arranged in a space in a side part in the container body, and blown from the blower fan is sent to the blower fan. A duct having one end connected thereto and the duct
Shape the opening edge of the container body so that the other end of the
An annular passage formed in a shoulder member formed therein;
An electric rice cooker characterized in that it can be supplied to an upper part of a gap formed between the stored inner pot and the container body through a ventilation passage formed by a communication port formed in a wall .