JPH1043045A - Rice cooker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify and lighten the structure of a lid in a way while in a way that while bringing no troubles for occur the practical sue even if an outer lid is touched by the hand when the lid is closed. SOLUTION: Only a space provided with a space distance to set the the outer surface temperature of a lid body to at most 70 deg.C is formed in a lid body 41. Since an insulating material or the like is absent in the lid body 541, the structure of the lid body 41 is simplified and lightened. Also the outer lid 42 is made of a plastic material so that there is not case that the outer lid 42 is too hot to be touched when the lid body 41 is closed. Further, a lower surface plate 44 of the lid is formed of a metal material so hat the radiation from the lower surface plate 44 of the lid to the outer lid 42 can be reduced to restrain the temperature rise of the outer lid 42.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rice cooker having a structure without a so-called inner lid in which a lid lower surface member of a lid directly faces an upper opening of a pan.

[0002]

Conventionally, glass wool as a heat insulating material is provided inside a lid constituting a rice cooker of this kind in order to prevent the temperature of a lower surface member of the lid forming the lower surface of the lid from lowering. Using a heat insulating plate for forming a heat insulating space made of a metal plate, or a plastic partition plate member or the like, heat insulating is provided between an outer lid forming the outer surface of the lid and a lid heater inside the lid. A space is provided. However, such a heat insulating structure inside the lid has not received much attention except that it has the effect of preventing the above-mentioned temperature lowering of the lid lower surface member and also suppressing the temperature rise of the outer lid.

[0003] Recent rice cookers have a structure in which a hinge spring is provided at a hinge portion of a lid, and the lid is automatically opened by utilizing the elastic force of the hinge spring. That is, since the lid is naturally opened by the hinge spring, there is no need to provide a handle on the upper surface of the lid, and a handle for holding the lid when opening the lid is not required at the top of the lid. When the handle is not provided directly on the lid, a neat design is realized in appearance, and the lid opening operation is automatically performed to improve the usability. However, when closing the lid, the lid must be pressed down by touching the upper surface of the lid against the elastic force of the hinge spring. It is necessary to suppress a rise in the temperature of the upper surface of the lid by a heat insulating structure inside the lid, which has not been given much importance until now.

On the other hand, in consideration of the environment and harm to the human body, there is a tendency to avoid using heat insulating materials such as glass wool, and instead of such heat insulating materials, the above-mentioned metal plate or plastic plate is used. The method of forming an insulated space inside the lid has a problem in the disposal process such that when the rice cooker is discarded, it takes time to separate the materials because the structure becomes complicated and the decomposition becomes difficult. . In addition, if the heat insulating structural member is inside the lid, the total weight of the lid increases, so that both the hinge spring and the hinge that give the lid an elastic force in the opening direction need to be strong. This causes a problem that the front of the rice cooker is lifted by an impact when the lid is opened in an empty pan. Thus, measures to suppress the temperature rise on the outer surface of the lid, and simplification of the structure and weight reduction of the lid are important issues.

[0005] In view of the above problems, the present invention provides a rice cooker that can be configured so that there is no practical problem even if the outer lid is touched by hand when closing the lid, and that the structure of the lid can be simplified and reduced in weight. Its purpose is to provide vessels.

[0006]

In order to achieve the above object, a rice cooker according to the present invention comprises an outer lid made of a plastic material forming an outer surface of a lid, and the lid directly facing an opening of a pot. A lid lower surface member made of a metal material forming a lower surface of the lid, and a lid heating means provided inside the lid body and mainly heating the lid lower surface member, between the lid heating means and the outer lid. Has a space distance such that the outer surface temperature of the outer lid is 70 ° C. or less during rice cooking.

According to the above construction, only a space is provided in the lid between the lid heating means and the outer lid so as to provide a space distance such that the outer surface temperature of the outer lid is 70 ° C. or less. So
The structure inside the lid is extremely simplified, and the weight is reduced. Therefore, environmental protection is achieved as much as the heat insulating material such as glass wool is not used, and industrial waste at the time of disposal is reduced and decomposition is facilitated. Further, since the outer lid is formed of a plastic material, practical obstacles such as the outer lid being hot and not touching when the lid is closed are removed unlike the case of a metal material. In addition, since the lid lower surface member directly facing the opening of the pot is formed of a metal material having good heat conductivity, heat radiation from the lid lower surface member to the outer lid is reduced, and the temperature of the outer lid rises. Can be suppressed.

[0008]

Hereinafter, an embodiment of the present invention will be described.
This will be described with reference to FIGS. Reference numeral 1 denotes a vessel body, which is a bottomed cylindrical inner frame 2 having an open upper surface, and an outer frame 3 having the inner frame 2 therein and forming an outer shell of the vessel body 1.
And a bottom plate 4 that covers the bottom side of the outer frame 3. The inner frame 2 serving as a container housing portion is made of PET resin containing glass fiber,
The pot 5 is formed in a shape substantially similar to the outer shape of the pot 5 removably accommodated in the inner frame 2.

[0009] The shape of the pot 5 for accommodating rice or water to be cooked is formed in a cylindrical shape with a bottom and an open top.
At the top of the outer surface of the pot 5, a flange-shaped handle 6 projecting horizontally outward is formed. The pan 5 is supported in a hung state by the handle portion 6 being placed on the upper end surface of the outer frame 3, and between the inner frame 2 and the pan 5 housed therein.
Except for the handle 6, a predetermined gap 7 of 1 to 4 mm is formed. The pot 5 is provided with a pot main body 8 mainly composed of, for example, an A3004 type aluminum material having excellent heat conductivity and corrosion resistance, and is provided from the outer bottom surface to the lower side of the pot main body 8. The heat generating layer 9 is made of a magnetic metal material.

Further, the overall shape of the pot 5 will be described in detail. Pot 5
The outer surface of the curve is connected to the lowermost portion 11 of the outer bottom surface of the pot 5 with a decreasing rate of the diameter increasing as the height decreases from a height h approximately at the middle of the total height H or about 1/3 of the total height H. When the pot 5 is placed on a flat table surface or the like, the lowermost portion 11 of the pot 5 comes into contact with the table surface or the like. The outermost peripheral portion 12 of the inner bottom surface facing the outermost peripheral portion of the lowermost portion 11 of the pan 5 has a diameter A2 of 25% to 75% (1/1) of the diameter A1 of the upper opening 13 of the pan 5.
4 to 3/4). The inner surface of the pan 5 has a vertical cross-sectional shape substantially along the outer surface of the pan 5, and faces the lowermost portion 11 from a side position approximately at the middle of the total height H or about １ ／ of the total height H. It is formed in the shape of a curved surface over the bottom surface to be formed. Here, the side surface refers to a portion from the upper opening 13 including the handle portion 6 to the outermost peripheral portion of the lowermost portion 11 (portion located at the outermost peripheral portion 12) in contact with a table surface or the like. The curved surface portion 14 having the above-mentioned curved inner surface is formed from to the bottom surface. The heat generating layer 9, which is a heat generating portion of the pot 5, is formed on the outer surface of the curved portion 14 of the pot 5.

Reference numeral 21 denotes a heating coil provided outside the inner frame 2 and serving as a pot heating device for causing the heat generating layer 9 of the pot 5 to generate heat by electromagnetic induction. The heating coil 21 has a curved surface portion from the lower side surface to the bottom surface of the pot 5 on the outer surface of the inner frame 2.
It is spirally wound and fixed at a position facing the 14 heating layers 9. The heating coil 21 may be provided in a portion other than this portion. However, the heating coil 21 is placed at a position facing the curved surface portion 14 of the pot 5 at least so that heat convection of water in the pot 5 is easily generated at the time of cooking rice. Preferably, 21 is provided. Heating coil
On the outer side of 21, a coil cover 22 having an insulating property in which high magnetic permeability material powder mainly composed of iron oxide or the like is mixed with a plastic material is provided, and the heating coil 21 projects upward to the center of the coil cover 22. The heat generating layer 9 is fixed to the provided cylindrical portion 22A to prevent the leakage of the magnetic flux and to efficiently heat the heat generating layer 9 by electromagnetic induction. By forming the coil cover 22 with insulating plastic mixed with a material powder having high magnetic permeability in this way,
With one functional component, both the fixing of the heating coil 21 and the prevention of magnetic flux leakage are performed, and the structure is simplified. 23 is the pan 5
The temperature sensor 24 is provided near the heat generating layer 9 and has a thermistor having a negative characteristic therein.
Is a thermal fuse provided on the outer surface of the inner frame 2.

Reference numeral 26 denotes a heating board provided with an inverter circuit component 27 for supplying a predetermined high-frequency current to the heating coil 21. The heating substrate 26 is disposed between the bottom plate 4 at the bottom of the container body 1 and the support 28 together with the cooling fan 30 provided with the motor 29 by the support 28 provided inside the container body 1. An intake port 31 is provided at the bottom of the bottom plate 4 facing the cooling fan 30, and an exhaust port 32 is provided at a side surface of the bottom plate 4 facing one side of the heating substrate 26. Support 28
Is provided upright on one side of the heating substrate 26. Between the support 28 and the front surface of the main body 1, an LCD 33 and an LED forming an operation panel 33 as display operation means are provided.
A display operation component 36 having 34 and various switches 35;
A power supply circuit component 37 other than the inverter circuit component 27 is
It is provided in a state of being mounted on. When the cooling fan 30 is rotated by energizing the motor 29, the air taken in from the intake port 31 is sent out from the heating substrate 26 to the exhaust port 32 through the substrate 38, and the air flows between the support 28 and the bottom plate 4. Each part in the space surrounded by is forcibly cooled. 39 is a power cord 40 provided on the lower rear side of the outer frame 3.
Is a code reel that winds up.

Reference numeral 41 denotes a lid that covers the upper opening 13 of the pot 5 so that it can be opened and closed. The lid 41 forms an outer surface of the lid 41,
An outer lid 42 made of a plastic material such as polypropylene or ABS resin, an outer lid cover 43 provided along the lower outer periphery of the outer lid 42, and a lid made of a metal material such as stainless steel or aluminum. It is mainly formed by a lid lower plate 44 directly covering the upper opening 13 of the pot 5 as a lower surface member. The outer lid 42 is formed into a three-dimensional appearance with excellent design by injection molding plastic, and can be freely colored, so that the degree of freedom in design can be improved. I have. Reference numeral 45 denotes a lid packing held between the outer lid cover 43 and the lid lower surface plate 44. A hinge shaft 46 is pivotally supported on the upper rear surface of the container body 1, while a clamp 41 for locking the lid 41 and the container body 1 is provided on the lid 41 opposite to the hinge shaft 46 or on the front side of the container body 1. A button 46A is provided. Although not shown, a cover body is provided inside the hinge shaft 46.
An elastic member, such as a torsion coil spring, for urging the 41 in the direction in which it is always opened is provided. The lid 41 is not provided with a special means such as a handle or a handle for opening the lid 41 by hand, and when the clamp button 46A is pushed and operated, the elastic opening force of the elastic member causes The lid 41 is automatically opened around the hinge shaft 46 as the center of rotation.

A concave portion 47 and a convex portion 47A are provided on the pot facing surface 44A of the cover lower plate 44 facing the pot 5, and the strength is improved by work hardening. If the depth of the concave portion 47 is large, the effect of improving the strength is high, but the surface may be difficult to wipe off. Therefore, it is preferable that the depth B is formed within about 1 mm. The shapes of the concave portion 47 and the convex portion 47A are not particularly limited, and are formed in consideration of design properties such as a circle, an ellipse, a triangle, and a turtle pattern. On the other hand, the inner surface 44B of the lid lower surface plate 44 facing the inside of the lid 41 has a flat shape or a protruding shape with a small protruding height that is small enough to allow adhesion of a lid heater 52 described later.

Next, a recess 47 is formed in the pot facing surface 44A of the lid lower plate 44.
A method of manufacturing the lid lower plate 44 in which the convex portion 47A is provided and the inner surface 44B is made flat or almost flat so that the pot facing surface 44A and the inner surface 44B have different surface shapes will be described. The first manufacturing method is based on a melt forging method.
In this melt forging method, aluminum heated in a molten state is poured into a lower mold, tightened by an upper mold, pressurized and solidified from above, molded and formed, and a recess 47 and the like are formed by a mold composed of a lower mold and an upper mold. A lid lower plate 44 having a predetermined shape is formed. The second manufacturing method is based on an aluminum die casting method. In this aluminum die casting method, a molten aluminum is poured into an upper and lower mold, solidified and formed, and a lower surface plate 44 having a predetermined shape in which a concave portion 47 and the like are formed by a metal mold is formed. According to such a melt-forging method and an aluminum die-casting method, the thickness C1 of the material on the outer peripheral side of the lid lower plate 44 is set to 3 to 6 mm.
The thickness C2 of the center portion side can be formed to be about 1.5 to 3 mm, which is thinner than the thickness C1 of the material, and the pot-facing surface 44A and the inner surface 44B have a non-similar shape and the thickness of the material. Can be formed into an uneven plate shape. Further, a third manufacturing method is a press molding manufacturing method. As shown in FIG. 3, the press forming method is to form a concave portion 47 by stamping in an aluminum plate having a material thickness of about 1 to 3 mm by press working, and then press forming into a predetermined shape.
In this press molding method, a concave mark is formed only on the surface corresponding to the pot facing surface 44A.

A cover lower plate formed by such a manufacturing method.
44 is subjected to a corrosion prevention treatment by alumite treatment (this alumite treatment may or may not be provided), and then the blasted pot facing surface 44A is coated with PFA resin (perfluoroalkoxy resin). After drying, PFA resin is applied again from above, and it is made of fluororesin by 2 coats and 2 bake and has a melting temperature of about 240 degrees Celsius.
The wear resistance of the layer is PTFE resin (ethylene tetrafluoride resin)
A stronger plastic film 48 is formed as compared with the above. Although the plastic film 48 has a higher abrasion resistance than the PTFE resin, the film thickness is usually about 10 μm to 20 to 120 μm by powder coating or the like so as to withstand abrasion when removing dirt. The surface of the lid lower plate 44, that is, the pot facing surface 44A is coated.

Inside the lid 41, a space 51 is formed as an internal space between the outer lid 42 and the lid lower plate 44. Inside the space 51, a lid mainly for heating the lid lower plate 44 is provided. A lid heater 52 as a heating means is attached to the upper surface of the lid lower plate 44, that is, the inner surface 44B, corresponding to the concave portion 47 and the convex portion 47A by an appropriate method such as fixing or bonding. Also, this lid lower plate 44
A cover temperature sensor 53 for detecting the temperature of the cover lower plate 44 is provided on the inner surface 44B of the cover, and the temperature of the cover lower plate 44 is controlled to a predetermined temperature in accordance with the temperature detected by the cover temperature sensor 53. ing. In this embodiment, the lid heater 52 having a long cord-shaped heater portion is laid on the inner surface 44B of the lid lower surface plate 44, and the lid heater 52 and the lid temperature sensor 53 are adhered from the upper surface with a double-sided tape (not shown). After that, although it is pressed and fixed by the aluminum foil 54, the lid lower plate 44 may be heated by electromagnetic induction using a heating coil instead of the lid heater 52.
In addition, in order to prevent dew condensation on the lid lower plate 44 at the time of cooking or uneven rice cooking, the pot facing surface 44A of the lid lower plate 44 is
The lid heater 52 is configured to be heated to a temperature not lower than the boiling temperature and not higher than about 150 ° C.

The lid heater 52 is electrically connected to a side heater 55 such as a cord heater for keeping the inner frame 2 warm by a parallel circuit. The lid heater 52 and the side heater 55 are connected by a series circuit to a cut-off power control element such as a triac, which is a control means of a lid heating device (not shown). At this time, the lid heater 52 and the side heater 55 may be configured so as to heat the lid lower plate 44 during rice cooking and heat keeping under predetermined power supply time control. In addition, the lid heater 52 and the side heater 55 perform warming and heating for keeping the rice to be warmed in the pan 5 at a predetermined temperature of 60 to 76 ° C. during the warming. Further, when the temperature of the pot facing surface 44A of the lid lower plate 44 is always higher than the temperature of the rice in the pot 5, the upper surface of the rice is dried, and conversely, the temperature of the pot facing surface 44A of the lid lower plate 44 becomes When the temperature is always lower than the temperature of the rice in 5, there is a problem that a large amount of dew is generated. Therefore, the temperature of the pot facing surface 44A of the lid lower plate 44 is
At least the pot-facing surface 44 of the lid lower plate 44 is such that a high period and a low period alternate with respect to the temperature of the rice in the pan 5.
The temperature of A is configured to be temporarily lower than the temperature of the rice in the pot 5.

Reference numeral 61 denotes a steam entry hole provided substantially at the center of the lid lower plate 44 and the pan 5.
The steam enters the steam port 62 from 61. Steam vent
The structure around 62 is described in detail.
A recess 63 is provided for mounting the
A steam port cover 65 having a steam discharge port 64 formed on the upper surface exposed to the outside of the lid 41, and a bottomed cylindrical bucket 66 provided inside the steam port cover 65 so as to be vertically movable. Assembled and configured. The bucket 66 is made of a metal material made of aluminum or stainless steel, or a plastic material such as polypropylene, and a bulging portion 67 corresponding to the bottom of the steam port 62 formed below the bucket 66 has a steam port cover 65.
Are provided so as to protrude from the lower surface opening 68. On the outer upper part of the steam port cover 65, a projection 70 is formed to be locked to the locked piece 69 of the outer lid 42. The engagement and disengagement of the locked piece 69 and the projection 70 The steam port 62 can be further attached and detached.

Reference numeral 71 denotes a steam port packing for sealing between the lower end of the concave portion 63 and the lid lower plate 44. This steam port packing 71
Is for preventing the invasion of steam into the lid 41, and when the steam port 62 is mounted in the recess 63, the steam port cover 65
The bent part 72 formed at the lower part of the outer periphery of the
A configuration in which the bottom surface of the bulging portion 67 of the bucket 66 is placed on the upper surface of the lid lower plate 44 exposed to the inner bottom surface of the concave portion 63 and closes the vapor intrusion hole 61 of the lid lower plate 44 while being in close contact with the inner end of the bucket 71. It has become. In addition, the bucket 66
A partition plate 74 having a plurality of communication holes 73 communicating the inside and the outside of the device is provided. At the center of the bulging portion 67 of the bucket 66, there is provided a return hole 75 through which the lumps collected inside the bucket 66 during rice cooking flow. The return hole 75 is a check valve made of an elastic member such as silicone rubber. It is in a state of being closed by the tongue piece 77 of 76. Therefore, the steam generated during the rice cooking enters through the steam entry hole 61 and abuts against the bottom surface of the bucket 66,
At this time, the pressure of the steam pushes the bucket 66 upward from the lid lower surface plate 44 and passes through a steam passage hole 78 formed between the outer surface of the bucket 66 and the inner surface of the steam port cover 65 to pass through the steam port cover. The steam is discharged to the outside of the lid 41 from the steam discharge port 64 on the upper surface of the cap 65. Thereafter, when the rice cooking is completed, the heating is stopped, and the process shifts to spots, the inside of the pot 5 becomes negative pressure, so that the check valve 76 moves toward the pot 5 and forms a lower portion of the check valve 76. From between the tongue piece 77 and the return hole 74, the bucket 66
The tonnage that has accumulated inside the container returns to the pot 5 side.

Also, when the temperature is kept warm, the pressure of the steam in the pot 5 decreases, and the bucket 66 is moved by its own weight.
It is placed on the upper surface of 44 and closes the vapor entry hole 61 of the lid lower plate 44. The lid heater 48 is disposed so as to surround the vapor port 62 in the vicinity of the vapor intrusion hole 61, that is, within a range of about 30 mm or less around the vapor port packing 71. When the lower plate 44 is heated, the vapor intrusion holes 61 near the lower plate 44 are heated, and the lid lower plate 44 is heated.
The bucket 66 in contact with is heated by heat conduction.

In the above configuration, when a high-frequency current is supplied to the heating coil 21 from the inverter circuit mounted on the heating board 26, an alternating magnetic field is generated in the heating coil 21 and the heating layer of the pot 5 located in the magnetic field An eddy current is generated in the pan 9 and the eddy current is converted into Joule heat, so that the heating layer 9 generates heat and heats the cooked rice inside the pan 5.

A lid heater 52 provided inside the lid 41
The amount of heating, i.e., the power consumption, may be set to, for example, 10 to 100 W in consideration of the configuration and size of the lid 41, and the heating capacity is not less than the minimum capable of heating the lid lower plate 44 to a predetermined temperature during rice cooking. And any condition that satisfies the conditions described below. The condition is that the vertical space distance of the space 51 between the lid heater 52, which is the lid heating means, and the outer lid 42 is about 5 mm or more and 70 mm or less. The spatial distance of the space 51 depends on the heating capacity of the lid heater 52, the temperature control conditions of the lid temperature sensor 53, and the like. The surface temperature of the outer surface of the container body, more specifically, the condition that the surface temperature from the front end to the rear part of the vessel main body 1 to the steam port 62 becomes 70 ° C. or lower when the room temperature is 30 ° C., and preferably 65 ° C. or lower Thus, the configuration is made as small as possible. Also, in the unlikely event that the control means of the lid heater 52 fails and the lid heater 52 is in a continuous energized state,
A space 51 is formed such that the plastic outer lid 42 does not melt by heat. That is, when the outer lid 42 is made of polypropylene, the melting temperature of the polypropylene is about 175 ° C., so that a space 51 at which the temperature is 170 ° C. or less is secured. This temperature varies depending on the type of resin material of the outer lid 42, but may be any temperature at which the outer lid 42 does not melt when the lid heater 52 is continuously energized. If the space 51 is formed so as to satisfy such conditions, in addition to the normal use during normal times, even if the control means of the lid heater 52 should fail, a heat insulating material or a heat insulating material is provided inside the space 51. Due to the simple structure of the lid 41 having no structural member, the temperature rise of the outer lid 42 can be sufficiently suppressed.

Incidentally, according to the results of the monitor test,
When the operation of closing the lid 41 is performed against the elastic opening force of the lid 41, the temperature at which the outer surface of the outer lid 42 can be touched with the hand is about 70 ° C. In addition, it was found that the limit of the temperature that can be endured by touching the outer surface of the outer lid 42 is different between men and women, and it is preferable that the limit is 65 ° C. or less for women. When the outer lid 42 is touched for a long time of about 10 seconds, it is desirable to keep the outer surface temperature of the outer lid 42 at 60 ° C. or less. Sometimes it is almost limited, so the outer lid 42 is not necessarily
Need not be suppressed to 60 ° C. or less. However,
From the viewpoint of safety, the lower the outer surface temperature of the outer lid 42 is, the better.However, the space distance of the space 51 inside the lid 41 is increased, and the entire rice cooker including the lid 41 is large. Therefore, it is desirable to reduce the size as much as possible within a range that does not hinder practical use.

On the other hand, if the outer lid 42 is made of a metal material instead of a plastic material, the difference in thermal conductivity between the two will cause the metal outer lid 42 to feel hotter even at the same temperature, and the outer lid 42 will feel hotter. If the outer surface temperature is not suppressed to 45 ° C. or lower, a state in which the lid 41 cannot be closed when the user touches it with his / her hand will be unbearable. From a practical point of view, it is difficult to realize such a case when the room temperature is high such as in summer, and therefore, the use of the metal outer cover 42 should be avoided. In addition, the efficiency of the lid lower surface plate 44 directly facing the pan 5 is deteriorated when a member having poor heat conductivity is used, and heat radiation to the outer lid 42 side is increased, and as a result, the outer surface temperature of the outer lid 42 is reduced. To rise. Therefore, it is preferable that the lid lower plate 44 be made of a metal material having good heat conductivity.

As described above, according to the present embodiment, a rice cooker having a so-called one-touch open type lid 41 is provided between a lid heater 52 and an outer lid 42. Since only the space 51 having a space distance such that the temperature becomes 70 ° C. or less is formed inside the lid 41, glass wool as a heat insulating material or a heat insulating space is formed inside the lid 41. There is no need to provide a separate heat-insulating structural member for
41, it is possible to extremely simplify the internal structure and reduce the weight. Therefore, not only is the use of a heat insulating material such as glass wool not required to protect the environment, but also, when the rice cooker is discarded, industrial waste is reduced and decomposition is easy. Further, since the weight of the lid 41 is reduced, the elastic member such as a hinge spring inside the hinge shaft 46 does not need to have a very high elastic strength. Therefore, when the lid 41 is opened in the empty pan, the problem that the front of the container body 1 is lifted by the elastic opening force of the elastic member can be eliminated. Further, since the outer lid 42 is formed of a plastic material, unlike the case where the outer lid 42 is formed of a metal material, when the lid 41 is closed, the outer lid 42 is hot and does not touch in practical use. Obstacles can be removed. Further, since the lid lower plate 44 directly facing the upper opening 13 of the pot 5 is formed of a metal material having good thermal conductivity, heat radiation from the lid lower plate 44 to the outer lid 42 is reduced. In addition, the temperature rise of the outer lid 42 can be suppressed.

That is, an outer lid 42 made of a plastic material forming the outer surface of the lid 41 and a lid lower plate 44 directly facing the opening 13 of the pot 5 and serving as a lower surface member of the lid 41 made of a metal material. And a lid heater 52 provided inside the lid body 41 and serving as a lid heating means for mainly heating the lid lower surface plate 44.
The outer surface temperature of the outer lid 42 is 70
By forming the space distance of the space 51 so as to be equal to or less than 0 ° C., even if the outer lid 42 is touched by hand when closing the lid 41, a configuration that does not cause a practical problem can be obtained, and the lid 41 The structure can be simplified and the weight can be reduced.

In such a configuration, the lid heater
By providing the space distance of the space 51 so that the temperature of the plastic outer lid 42 does not melt when the 52 is in a continuous energized state, even if the control means of the lid heater 52 fails, There is no possibility that the outer lid 41 is melted, and safety can be ensured.

Although different from the embodiment, in a rice cooker having an inner lid on the lower surface of the lid, it is necessary to increase the amount of radiant heat from the lid heater in order to prevent dew condensation on the inner lid. Therefore, the temperature of the lower surface of the lid needs to be higher than that of the structure without the inner lid as in this embodiment. Therefore, the rice cooker having the structure without the inner lid as in the present embodiment and capable of suppressing the temperature of the lid lower surface plate 44 to a certain extent is less heat-sensitive to the outer lid 42 as a result, and the inside of the lid 41 Large space
Even if 51 is not secured, the above operation and effect can be easily achieved.

By the way, as a conventional rice cooker of this kind,
For example, Japanese Patent Application Laid-Open No. 7-204086 proposes a structure without a so-called inner lid (without an inner lid) in which an upper opening of a pot is directly covered by a lid lower surface member forming a lower portion of the lid. The rice cooker with such a structure is easy to use because there is no trouble of attaching and detaching the inner lid, and there is no need to clean the inner lid. On the other hand, a lid that is soiled due to the adhesion of rice (starch-dissolved water) during cooking. It is necessary to wipe the lower surface of the body. For this reason, when wiping off towels, if you forcibly wipe off the adhered dirt or rub it with Scotch Bright, etc., the surface fluorine coating (PTFE resin) will be scratched, and moisture will enter from this scratch during use, There is a problem that the base material of the lid lower surface member is corroded or the fluorine coating is peeled off.

In view of these problems, in the present embodiment, while taking advantage of the elimination of the inner lid, the fluorine coating is less likely to be damaged, and corrosion and peeling of the base material of the lid lower surface member can be reduced. It aims to get a rice cooker.

That is, the rice cooker according to the present embodiment has a lid lower surface plate 44 that forms the lower surface of the lid 41 instead of the inner lid.
Since the structure is such that the upper opening 13 of the pot 5 is covered, there is no need to remove and attach the inner lid, and there is no need to clean the inner lid, which is practically convenient. Further, the pot facing surface 44A corresponding to the surface of the lid lower plate 44 is coated with a PFA resin which is superior in abrasion resistance as compared with a normal PTFE resin. Since the film thickness is set to 20 to 120 μm, which is thicker than usual, it is possible to secure abrasion resistance sufficient to remove sticking of dirt in practical use, corrosion of the base material due to scratching, peeling of fluorine coating Can be prevented. Further, since the thickness of the plastic film 48 is larger than that of the conventional one, the occurrence of pinholes in the coating layer is reduced, and from this point, the corrosion of the base material can be further prevented.

Further, since the pot facing surface 44A of the lid lower plate 44 has few pinholes and has a water-repellent effect as described above, in order to prevent the rice in the pot 5 from drying during the heat insulation,
Even when the temperature of the lid lower plate 44 is temporarily lower than the rice temperature, the dew adhered to the pot facing surface 44A of the lid lower plate 44 becomes a polka dot and is less likely to fall from the lid lower plate 44 to the rice upper surface. This has the effect of preventing the conventional problem that dew drops on the upper surface of the rice and sticks the rice. Further, as in the present embodiment, the concave portion 47 and the convex portion 47A are formed on the pot facing surface 44A of the lid lower plate 44.
When the is provided, the adhesion of polka dots at the time of dew condensation due to unevenness is dispersed, and the polka dots stick together and increase the weight,
Furthermore, polka dots are less likely to fall on the upper surface of rice, and the effect is enhanced.

According to the results of the experiment, non-adhesiveness on the pot-facing surface 44A of the lid lower plate 44 is more secure when the plastic film 48 having a large thickness and few pinholes is used as in this embodiment. In addition, while having excellent water repellency, pot 5
Even if the temperature of the lid lower plate 44 is temporarily lowered below the rice temperature in order to prevent the rice inside from drying, the dew attached to the pot facing surface 44A of the lid lower plate 44 is dispersed in a polka dot shape, and Good heat retention without falling was achieved.

The plastic film 48 coated on the pot-facing surface 44A of the lid lower plate 44 can improve the abrasion resistance most when PFA resin is used, but other PTFE resin or EFP resin can be used. Even with other fluororesins, the film thickness is 20 to 120 μm as in this embodiment.
If formed, the damage is unlikely to reach the base material and the number of pinholes is reduced, so that an effect almost equivalent to that of this embodiment can be exerted.

As described above, the lid 41 directly facing the pot 5
The surface of the lid lower plate 44 as the lid lower member forming the lower surface of the lid, that is, the pot facing surface 44A is coated with a fluororesin having a film thickness of 20 to 120 μm, and a lid heating means provided on the back side of the lid lower plate 44. If the lid heater 52 is configured to heat the surface temperature of the lid lower plate 44 during the heat keeping so as to be temporarily lower than the heat retaining temperature of the rice in the pot 5, the cover lower plate 44 becomes dirty. When the sticking is adhered, even if the pot facing surface 44A of the lid lower plate 44 is strongly rubbed and wiped off, the fluorine coating is hardly damaged and the base material of the lid lower plate 44 is not damaged. It is difficult to reach.
Therefore, by eliminating the inner lid, it is possible to obtain a rice cooker which can take advantage of improved usability, is less likely to damage the fluorine coating, and can reduce corrosion and peeling of the base material of the lid lower plate 44. it can. In addition, even if the surface temperature of the lid lower plate 44 is temporarily lower than the temperature of the rice in order to prevent the rice in the pan 5 from drying during the heat retention, the rice adheres to the pot facing surface 44A of the lid lower plate 44. The dew does not drip on the upper surface of the rice, and good heat retention without drying and dew can be realized.

In such a configuration, when the fluororesin is a PFA resin, the abrasion resistance on the pot facing surface 44A of the lid lower plate 44 can be further improved. further,
When the pot-facing surface 44A of the lid lower plate 44 is formed in an uneven shape, the dew attached to the pot-facing surface 44A is dispersed in a polka dot shape, and the rice in the pot 5 is prevented from drying, but does not fall off further. Good heat retention can be performed.

It should be noted that the present invention is not limited to the above embodiment, and various modifications can be made within the scope of the present invention. For example, as shown in FIG. 4, instead of the heating coil 21 in the present embodiment, a rice cooker 81 is provided at the bottom of the inner frame 2 as a pot heating device, and is placed on a heater plate 82 by radiant heat from the rice cooker 81. The pot 5 may be configured to be heated. In FIG. 4 as well, a space is provided between the plastic outer lid 42 and the lid heater 52 provided on the back surface of the metal lid lower surface plate 44 such that the outer surface temperature of the outer lid 42 becomes 70 ° C. or less during rice cooking. A space 51 having a distance is formed, and functions and effects similar to those in FIG.
In FIG. 4, the same parts as those in FIG. 1 are denoted by the same reference numerals.

[0039]

The rice cooker according to the present invention has an outer lid made of a plastic material forming the outer surface of the lid, and a lower surface of the lid made of a metal material directly facing the opening of the pot and forming the lower surface of the lid. Member, a lid heating means provided inside the lid body and mainly heating the lid lower surface member, between the lid heating means and the outer lid, the outer surface temperature of the outer lid during cooking rice, 7
The inner space is formed with a clearance so as to be 0 ° C. or less. When closing the lid, the outer lid can be touched by hand without any practical problems. And weight reduction can be realized.

[Brief description of the drawings]

FIG. 1 is an overall sectional view of a rice cooker showing one embodiment of the present invention.

FIG. 2 is a sectional view of the upper cover lower plate.

FIG. 3 is a sectional view of a cover lower plate showing another embodiment of the present invention.

FIG. 4 is an overall sectional view of a rice cooker showing another embodiment of the present invention.

[Explanation of symbols]

 5 pan 41 lid 42 outer lid 44 lid lower plate (lid lower member) 51 space (inner space) 52 lid heater (lid heating means)

Claims (1)

[Claims] 1. An outer lid made of a plastic material forming an outer surface of a lid, a lower surface member made of a metal material directly facing an opening of a pot and forming a lower surface of the lid, A lid heating means provided inside to mainly heat the lid lower surface member, wherein between the lid heating means and the outer lid, the outer surface temperature of the outer lid becomes 70 ° C. or less during rice cooking. A rice cooker characterized by forming a spatial distance.