JPH0815455B2 - 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 for use in general households and the like, which is equipped with an induction heating source and puts an object to be cooked in a pan for heating.

[0002]

2. Description of the Related Art As an electric rice cooker equipped with an induction heating source for cooking an object to be cooked in a pan, one having the following structure is known. That is, in FIG.
Reference numeral 1 denotes a cylindrical outer case whose upper and lower surfaces are open, and a bottom plate 103 having supporting legs 102 is fixed to the lower surface of the outer case by screwing. Reference numeral 104 denotes a pot storage portion formed of, for example, heat-resistant plastic, and a flange portion 104a provided at an upper end portion of the pot storage portion is fixed to an upper surface of the outer case 101 by screwing. Reference numeral 105 denotes a first induction coil embedded in the side surface portion 104b of the pan storage portion 104 by integral molding, and 106 denotes a bottom surface portion 104c of the pan storage portion 104.
2 is a second induction coil embedded by integral molding. Reference numeral 107 denotes a pot made of a magnetic material such as iron, which is detachably placed on the bottom surface 104c of the pot housing 104. Reference numeral 108 denotes, for example, a magnetic thermostat fixed through a support plate 109 in a through hole 104d provided in the central portion of the bottom surface 104c of the pan storage unit 104. It is biased to come into close contact with the bottom surface portion 107b of the pan 107. Reference numeral 110 is a heat-sensitive portion 110a that detects the temperature of the side surface portion 107a of the pan 107, and is composed of, for example, a thermistor.
With this temperature detection switch, the heat-sensitive portion 110a has its base end inserted through an insertion hole 111 provided in the side surface portion 104b of the pan storage portion 104, and is always biased toward the pan 107 by a spring 112. The tip of the heat-sensitive portion 110a is adapted to be pressure-bonded to the side surface portion 107a of the pan 107. Reference numeral 113 denotes a lid having a knob 114, which is detachably mounted on the collar portion 104a of the pot storage portion 104. Reference numeral 115 denotes a control board fixed to the upper surface of the bottom plate 103, in which a part of the electric circuit is provided.

[0003]

In the conventional electric rice cooker described above, the pan storing portion 104 is formed of heat resistant plastic, and the induction coil 10 self-heats due to a large current.
5, 106 are embedded by integral molding. However, among the above heat-resistant plastics, the cost is relatively low, and injection molding is possible. For example, thermoplastics such as PPS have low impact resistance, and when the object to be heated is put in, it is 5 kg.
Care needs to be taken in and out of the pan 107 as described above, and there is a risk of cracking if handled roughly. Furthermore, even if the heat resistant temperature is high, it is 2
The temperature is 60 ° C., and in an abnormal temperature rise state due to a circuit failure or the like, the temperature generally rises toward the upper layer and the temperature of the collar 104a supported by the outer case 101 abnormally rises, and the load of the pan 107 is increased. In some cases, it may become unusable due to a drop in the air, or it may come into contact with the control board 115 to ignite and become an abnormal shape.

The present invention solves the above problems,
An object of the present invention is to provide an electric rice cooker having an induction heating source capable of increasing the shock resistance of the pot storage portion and preventing abnormal heating of the pot storage portion.

[0005]

To achieve the above object, the present invention provides a cooker main body, a pan that is detachably accommodated in the cooker main body, and a lid that covers the cooker main body so that the cooker main body can be opened and closed. A cooker body, the storage portion of the pan in the cooker body is formed of a protective frame bottom portion using a resin material and a protective frame side surface portion using a metal material, and an induction coil is arranged on the protective frame bottom portion. In this configuration, the uppermost part of the induction coil and the lowermost part of the side surface of the protective frame are separated from each other.

[0006]

In the above structure, the magnetic flux is passed through the pan with a non-magnetic material, the impact resistance is lower than that of metal, the heat resistance temperature is low, and the thermal conductivity is low, and the protective frame bottom is formed of a thermoplastic material, On the other hand, since the side surface of the protective frame is formed of a metal material that has high impact resistance, heat resistant temperature, and thermal conductivity and is low in cost, the side surface of the protective frame that is susceptible to impact when the pot is put in or taken out, etc. Thermal shock absorber with improved shock resistance, improved strength when abnormal temperature rise in the upper layer due to circuit failure, etc. to prevent structural destruction and ignition, is inexpensive, and forcibly shuts off the circuit at abnormal high temperature Can be made sensitive to a local temperature rise or a sudden temperature rise by contacting the side surface of the protective frame, further enhancing safety.

Further, since the uppermost part of the induction coil and the lowermost part of the side surface of the protective frame are arranged apart from each other, it is possible to prevent the side surface of the protective frame, which is a metal material, from being induction-heated by the magnetic flux of the induction coil. It is possible to prevent the side surface of the protective frame from having an abnormal temperature and to thermally deform the bottom of the protective frame made of resin.

[0008]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing an electric rice cooker according to an embodiment of the present invention. In FIG. 1, inside the main body 1 of the cooking device having a substantially cylindrical shape, a bottom portion 3 of a protective frame which is a storage portion for the pan 2 is provided.
And the protective frame side surface portion 4 are provided. The protective frame bottom 3
Is made of a non-metallic resin material, for example, thermoplastic, and is provided with an undercut receiving portion (connecting portion) A6 which is connected to the flange A5 on the bottom side of the protective frame side surface portion 4 and has an impact resistance. Even if the resin material is low, the surfaces are bonded together so that the bonding strength is increased. On the other hand, the protective frame side surface portion 4 is formed of a metal material such as an aluminum-plated steel sheet, and a flange A5 and a flange B7, which are subjected to strength by outwardly facing flanges, are provided on the bottom portion and the upper portion, respectively. The flange A5 is as described above. Receiving part A of the bottom 3 of the protective frame
6, the flange B7 is connected to the undercut receiving portion B9 of the upper frame 8. The pot 2 is formed of, for example, a clad steel plate having an outer surface made of a magnetic material, and the pot flange 10 is supported by abutting the upper frame 8. The induction coil 11 is arranged on the outer surface of the protective frame bottom portion 3 so as to face the bottom portion of the pan 2 in order to enhance the cooling effect, and is held between the induction coil 11 and the protective frame cover 12 screwed to the protective frame bottom portion 3. A ferrite 13 is attached to the outer surface of the protective frame cover 12 to enhance the inductive coupling and to protect the outside from the magnetic field.
Here, the lowest part of the protective frame side surface part 4 and the uppermost part of the induction coil 11 are arranged at a distance of 15 to 30 mm,
The side surface portion 4 of the protective frame does not abnormally heat due to induction heating, and has the longest dimension so as to reduce the cost. Further, for example, a heater A14 having a covering insulation is attached to the side surface portion 4 of the protective frame, and a thermal fuse 15 which is a heat-sensitive operating body for interrupting the circuit at an abnormal temperature is further attached by a fixing member 16. A space between the outer case 1a of the cooker body 1 and the side surface 4 of the protective frame is filled with a heat insulating material 17 above the induction coil 11 to enhance the protection performance and prevent the temperature rise of the outer case 1a.

On the upper portion of the upper frame 8 of the cooker body 1, a hinge portion 1 is formed by integrally molding a lid 18 made of resin on the upper frame 8.
A pin 9 supports the pin 9 so as to be openable and closable. A handle portion 21 is provided on the upper surface of the lid body 18, and an inner cover 22 is fixed to the inner surface via a heat insulating material 23. Further, the engaging portion 2 is integrally formed on the opposite side of the upper frame 8 from the hinge portion 19.
4 is provided, and the engaging lever 2 is attached to the lid 18 so as to face the same.
5 is rotatably provided via a pin 26, and the lid 18
When is closed, the engagement lever 25 is engaged with the engagement portion 24 by being biased by the spring 27. When opening the lid 18, the button 28 attached to the engagement lever 25 is operated. A support pin 29 is provided on the lower surface side of the inner cover 22 on the lower surface of the lid body 18.
And the inner lid 30 is attached to the support pin 29 so as to be movable up and down, and is always urged downward by the packing 31 to close the pot 2 by pressing it against the pot 2 when the lid 18 is closed. I am trying to get it. Further, for example, a heater B32 which is covered and insulated is attached to the upper surface of the inner cover 22, and its lead wire is connected to an electric circuit (not shown) provided in the cooker main body 1 via the hinge portion 19.

As for the temperature of the pot 2, the contact 33 in thermal contact with a thermistor (not shown) is the sensor spring 3
It is urged by 4 and comes into contact with the bottom of the pot 2 to sense it. The temperature information detected by the thermistor is transmitted to an electric circuit (not shown) to control the electric power of the induction coil 11, the heater A14 and the heater B32.

In the electric rice cooker having the above-mentioned structure, for example, in the case of rice cooking, if a proper amount of rice and water are put in the pot 2 and a switch of an operation panel (not shown) is pressed to turn on electricity, the thermistor temperature sensing and electric By the program of the circuit, the induction coil 11, the heater A14, and the heater B32 can be power-controlled to cook rice and keep the temperature. Then, a storage portion for storing the pan 2 inside the cooker main body 1 is formed by the protective frame bottom portion 3 and the protective frame side surface portion 4, and the protective frame bottom portion 3 has impact resistance, heat resistance and thermal conductivity of metal. Although it is lower, it is made of a non-magnetic material that is easy to mold and uses a non-metallic material such as thermoplastic that allows magnetic flux to pass through the pan 2. It also has an impact when the pan 2 that contains an object to be heated and weighs 5 kg or more is taken in and out. Since a metal material such as an aluminum-plated steel sheet having high impact resistance, heat resistance and thermal conductivity, and low cost is used for the side surface portion 4 of the protective frame which is easily affected by the heat, structural damage such as cracking occurs even in rough handling. There is no such thing,
In addition, even when the abnormal temperature rises due to various factors, structural damage and ignition do not occur in the rising part that becomes the highest temperature,
Due to the high thermal conductivity, heat is dispersed and the temperature is lowered. Further, since the temperature fuse 15 which is a heat-sensitive operating body that shuts off the circuit when the abnormal temperature rises is attached to the outer surface of the side surface 4 of the protective frame, it operates sensitively to a local abnormal temperature rise or a sudden temperature rise. High safety.

Further, since the bottom of the protective frame is made of a resin material, the receiving portion A6, which is the connecting portion with the side surface 4 of the protective frame, can be easily molded, and the productivity of the pan storage portion can be improved.

Further, since the uppermost portion of the induction coil 11 and the lowermost portion of the protective frame side surface portion 4 are arranged apart from each other, the protective frame side surface portion 4 which is a metal material is induction-heated by the magnetic flux of the induction coil 11. Can be suppressed, and in particular, the temperature in the vicinity of the receiving portion A6, which is the connecting portion, can be prevented from rising abnormally, and the reduction in connecting strength due to thermal deformation of the receiving portion A6 can be prevented.

[0015]

As described above, in the electric rice cooker of the present invention, the storage portion for storing the pan in the cooker body is formed by the protective frame bottom portion and the protective frame side surface portion, and especially when the pan is taken in and out, a shock is generated. A metal material with high impact resistance, heat resistance and thermal conductivity, and low cost is used on the side surface of the protective frame, which is easily subject to heat and temperature rises. The strength at the time of abnormal temperature rise of the upper layer due to the above is also improved, and the heat is dispersed to lower the temperature, so that structural destruction or ignition does not occur.

Further, since the uppermost part of the induction coil and the lowermost part of the side surface of the protective frame are arranged apart from each other, it is possible to prevent the side surface of the protective frame, which is a metallic material, from being induction-heated by the magnetic flux of the induction coil. It is possible to prevent the temperature in the vicinity of the connecting portion between the side surface portion of the protective frame and the bottom portion of the protective frame from becoming an abnormal temperature, and to prevent the resin-made protective frame bottom portion from being thermally deformed.

[Brief description of drawings]

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

FIG. 2 is a sectional view showing a conventional electric rice cooker.

[Explanation of symbols]

 1 Cooking device main body 2 Pan 3 Bottom part of protective frame 4 Side part of protective frame 11 Induction coil 18 Lid

Claims (1)

[Claims] 1. A cooker main body, a pan that is detachably accommodated in the cooker main body, and a lid that covers the cooker main body so that the cooker main body can be opened and closed, and an accommodating portion for the pan in the cooker main body. Is formed of a protective frame bottom portion using a resin material and a protective frame side surface portion using a metal material, and an induction coil is arranged on the protective frame bottom portion, and the uppermost portion of the induction coil and the protective frame side surface portion are minimum. An electric rice cooker placed apart from the other parts.