JPH119465A - Heat insulating material for cooker and cooker using heat insulating material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To set a heat insulating material used for a rice cooker and warmer superior in heat insulating performance and assemblage and to reduce the price. SOLUTION: A heat insulating material 1 is so formed that a lot of hollow powder 3 composed of glass and ceramic is contained in a heat insulating main body 2 composed of a resin material such as silicone and polypropylene. The hollow powder 3 material has higher melting point and hardness than the material of the heat insulating material main body 2. This constitution can form the material by just mixing the hollow powder 3 into a molten resin material. When the heat insulating main body 2 is formed into a prescribed shape, there is no possibility of smashing of the hollow powder 3 smashed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat insulating material for a cooking vessel which is a device for keeping water boiling and keeping heat, such as an electric water heater and a jar rice cooker, and a cooking vessel using the heat insulating material.

[0002]

For example, in order to improve the heating efficiency of a heating device such as an electric water heater or a jar rice cooker, the heat of the heating element is transmitted to the side of the object to be heated such as a container or a lid, while the heat radiation or It is important how to suppress the escape of heat to the heated body side due to heat conduction and improve the efficiency of one-side heating to the heated body side. Further, in order to improve the heat retention efficiency, a problem is how to prevent the heat of the object to be heated such as the container or the lid once stored from escaping by heat radiation or heat conduction. In order to cope with such a problem, a heat insulating material is provided outside the heating element to improve the efficiency of single-sided heating,
A configuration in which a heat insulating material is provided around the container to improve heat retention will be adopted.

It is important for the heat insulating material to have a low thermal conductivity and a low specific gravity in terms of a heat insulating effect, and a high heat resistance is also required depending on use conditions. For this reason, glass fibers, ceramic fibers, ceramic powders, etc. are generally hardened to contain air with a void inside using a phenolic or acrylic adhesive, or as Japanese paper. The mainstream is those that have been dissolved and precipitated in water. In addition, the air itself also serves as a medium for transmitting heat, and as the air moves through the air gap, the heat insulation effect is reduced. is there. Further, a heat insulating structure is also employed in which a closed space is formed between a pair of plate members and the space is evacuated or evacuated.

[0004] However, the hardened fiber or powder has a problem that the working environment is deteriorated at the time of assembling work because the fiber or powder is scattered during handling. Further, when the aluminum foil is bonded, there is a problem in that the odor of the adhesive for bonding the aluminum foil is generated. In addition, vacuum insulation has a problem that it is expensive to manufacture and it is difficult to form a heat insulating material into a complicated shape.

[0005] For these reasons, in the conventional electric water heater or electric jar rice cooker, instead of the above-mentioned heat insulating material, an unsealed heat insulating space is formed by partitioning with an aluminum plate or a steel plate, or silicone or other materials are used. In many cases, a foam of a polypropylene resin is used as a heat insulating material, but these have a disadvantage that the heat insulating effect is weak.

Further, a heat insulating material obtained by solidifying fibers or powders is crushed and reduces the internal voids, so that the heat insulating effect becomes thin. Therefore, when the heat insulating material is disposed in the main body of the equipment, a sufficient space for the heat insulating material to be crushed is required. In addition, the heat insulating structure using the heat insulating plate requires a space for forming a predetermined heat insulating space, and in any case, there is a problem that the size of the main body of the device must be increased.

An object of the present invention is to solve such a problem, and a first object of the present invention is to provide an inexpensive heat insulating material for a cooking vessel which has high heat insulating performance, is excellent in assemblability, and is inexpensive. I do. A second object is to provide an inexpensive cooking container which has high heating efficiency or heat retention efficiency, is excellent in assemblability, and is inexpensive.

[0008]

In order to achieve the first object, a heat insulating material for a cooking vessel according to the present invention comprises a member having a low hardness and a hollow member having a higher hardness than the member. It is a combination of members.

In the heat insulating material having such a configuration, there is no problem of generation of harmful dust, high heat insulating performance can be obtained by a member having a hollow inside, and production is easy and inexpensive.
Further, the heat insulating material can be formed into a free shape by using a member having a low hardness. However, since the member having a hollow inside has a high hardness, the member is not crushed by the molding and the heat insulating performance is not impaired.

In order to achieve the first object, the heat insulating material for a cooking container according to the second aspect of the present invention provides a member in which a resin material such as a silicone resin or polypropylene is reduced in specific gravity by foaming or the like. It contains a member having a high melting temperature and a high hardness and having a hollow inside.

In the heat insulating material having such a configuration, there is no problem of generation of harmful dust, and very high heat insulating performance can be obtained by a member having a low specific gravity by foaming a resin material and a member having a hollow inside. It is easy and inexpensive to manufacture.
In addition, since a member having a hollow inside has a higher melting temperature than a resin material, even if a member having a hollow inside is mixed with a melted resin for molding of a heat insulating material, this member does not melt. Hollows in the member are maintained.

In order to achieve the first object, the heat insulating material for a cooking container according to the third aspect of the present invention comprises a low-hardness member made of a resin material such as silicone resin or polypropylene, and a glass or ceramic material. It is formed by combining a member having a hardness higher than that of the resin material and having a hollow interior and a reduced or substantially evacuated state.

In the heat insulating material having such a configuration, there is no problem of generation of harmful dust, high heat insulating performance can be obtained by a member having a hollow inside, and production is easy and inexpensive.
Further, the heat insulating material can be formed into a free shape by a low-hardness member made of a resin material. However, since the hollow member has a high hardness, the heat insulating material is not crushed by the molding and the heat insulating performance is not impaired. At the same time, since the hollow member has high hardness, the inside thereof can be decompressed or almost evacuated, but the heat insulating performance is further improved.

According to a fourth aspect of the present invention, in order to achieve the first object, the heat insulating material for a cooking container is made of glass or ceramic inside a plastic resin such as a fluorine resin, a polypropylene or a silicone resin, and has a hollow inside. A plurality of fine powders.

In the heat insulating material having such a configuration, there is no problem of generation of harmful dust, a high heat insulating performance can be obtained by a member having a hollow inside, and production is easy and inexpensive.
Generally, glass and ceramics have a higher melting temperature than plastic resin, so even if glass or ceramic powder is mixed with the melted plastic resin to form a heat insulating material, this glass or ceramic will not melt. In addition, since the powder is fine, the powder does not collapse due to the pressure during molding, and the hollow portion in the powder is maintained.

According to a fifth aspect of the present invention, there is provided a heat insulating material for a cooking vessel, wherein a member made of glass or ceramic powder and having a hollow inside is provided on a surface of a member forming a heat insulating structure in order to achieve the first object. It is a combination or coating of the layers involved.

In the heat insulating material having such a configuration, there is no problem of generation of harmful dust, high heat insulating performance can be obtained by a member having a hollow inside, and production is easy and inexpensive.
Moreover, according to the joining or coating means, the heat insulating layer can be formed only on the necessary portions of the members forming the heat insulating structure, and the cost can be reduced.

According to a sixth aspect of the present invention, in order to achieve the second object, in order to achieve the second object, the melting temperature of the flame-retardant plastic resin having a higher heat-resistant temperature than the operating temperature of the heating element is higher than that of the plastic resin. A heat insulating material made of a material having high hardness and high hardness and containing a hollow member is disposed outside the heating element.

In the heat insulating material having such a configuration, there is no problem of generation of harmful dust, high heat insulating performance can be obtained by a member having a hollow inside, and production is easy and inexpensive.
Also, since the inside hollow member has a higher melting temperature than the plastic resin, for molding the heat insulating material, even if the hollow hollow member is mixed with the melted plastic resin, this member does not melt, The hollow in this member is maintained. Then, the heat generated by the heating element is prevented from escaping to the outside by such a heat insulating material.

According to a seventh aspect of the present invention, in the cooking container according to the sixth aspect of the present invention, the heating element is joined to one surface of the heat insulating material.

Thus, the escape of the heat generated by the heat generating element is more reliably suppressed, and the heat insulating material and the heat generating element can be handled together during assembly.

In order to achieve the second object, the cooking container according to the invention of claim 8 is characterized in that a plastic resin such as a fluororesin or a silicone resin having a heat-resistant temperature higher than the temperature of the container when the container is heated is used. A heat insulating material having a melting temperature higher than that of the plastic resin and made of a material having a high hardness and containing a hollow member is disposed around the container.

In the heat insulating material having such a configuration, there is no problem of generation of harmful dust, high heat insulating performance can be obtained by a member having a hollow inside, and production is easy and inexpensive.
In addition, since a member having a hollow inside has a higher melting temperature than a plastic resin, even if a member having a hollow inside is mixed with a melted resin for molding of a heat insulating material, this member does not melt. Hollows in the member are maintained. Then, the escape of the heat stored in the container is suppressed by such a heat insulating material.

According to a ninth aspect of the present invention, in the cooking container of the sixth or seventh aspect, the plastic resin is formed of a foam.

As a result, the heat insulating performance of the heat insulating material is further improved, and the heating efficiency and the heat retaining efficiency of the cooking vessel are further improved.

A cooking container according to a tenth aspect of the present invention is that the container is provided with a magnetic metal material, and a resin coating layer including a hollow member is formed on an outer surface of the container containing the magnetic metal material. The magnetic metal material is heated by a heating coil for electromagnetic induction heating provided outside to heat the container.

The resin coating layer as a heat insulating material has no problem of generation of harmful dust, high heat insulating performance can be obtained by a member having a hollow inside, and production is easy and inexpensive. And in the cooking container for electromagnetic induction heating having the characteristic that the container itself generates heat, the resin coating layer suppresses the heat generated by the container from escaping outward, thereby increasing the heat retaining property of the container, Temperature rise on the outer surface of the container is suppressed.

According to an eleventh aspect of the present invention, in the cooking container according to the tenth aspect, the resin coating layer is mainly made of a non-adhesive material such as a silicone resin or a fluorine resin after coating, and the inside is hollow. It is a material that contains the components described above.

By containing a hollow member, even if the surface of the resin coating layer has irregularities in a granular form, the main body of the resin coating layer is made of a non-adhesive material. Adhesion of dirt to the surface of the resin coating layer is prevented, and even when dirty, it can be easily cleaned.

[0030]

Hereinafter, embodiments of the present invention will be described.
This will be described with reference to the drawings. First, first to fourth examples of the heat insulating material for a cooking container will be described with reference to FIGS. In these drawings, reference numeral 1 denotes a heat insulating material. The heat insulating material 1 includes a plurality of hollow powders (a member having a high hardness and a hollow inside) inside a heat insulating material body (low-hardness member, plastic resin, resin material) 2. , Fine powder) 3. These hollow powders 3 each have a hollow portion 4 inside and are fine with a particle size of about 10 to 100 μm. Further, the inside of the hollow portion 4 is depressurized or substantially evacuated. Alternatively, it may be configured such that a gas other than air is included and the pressure is reduced or substantially reduced.

Examples of the material of the heat insulating material body 2 include various resin materials such as silicone rubber (silicone resin), fluorine rubber, polyurethane, fluorine resin, polypropylene, polyethylene, polyethylene terephthalate, polybutylene terephthalate, polyamide and polyether sulfone. Among them, a material having heat resistance that can withstand the environmental temperature is selected according to the use environment. As a material of the hollow powder 3, glass or ceramics such as alumina and titania are selected. In any case, the material of the hollow powder 3 is higher in hardness than the material of the heat insulating material body 2,
In addition, a material having higher heat resistance and higher melting temperature than the material of the heat insulating material main body 2 is used.

In the first example shown in FIG. 1, the heat insulating material 1 alone is made of the heat insulating material main body 2 containing the hollow powder 3.

The heat insulating material 1 of the second example shown in FIG. 2 is provided on one surface of a substrate material 5 which is a member forming a heat insulating structure.
The heat insulating layer 6 made of the heat insulating material main body 2 containing the hollow powder 3 is joined or coated. As means for this coating, painting or printing, silk printing, etc. can be used. Examples of the material of the substrate material 5 on which the heat insulating layer 6 is provided include a plastic resin, an iron plate such as a steel plate, a stainless steel plate, a surface-treated iron plate or an aluminum plate,
For example, aluminum die casting or forged aluminum molten material is used.

The heat insulating material 1 of the third example shown in FIG. 3 is obtained by reducing the specific gravity of a heat insulating material body 2 made of a resin material such as silicone resin or polypropylene by foaming or the like. Apart from 4, the inside of the heat insulating material body 2 itself also includes a large number of hollow portions 7 formed by foaming or the like. These hollow portions 7 are, for example, air inside, and are independent of each other.

Further, the heat insulating material 1 of the fourth example shown in FIG.
In the heat insulating material 1 of the third example, an aluminum foil 8 is adhered to one surface of the heat insulating material main body 2, and a linear heating element 9 is further fixed thereon by a double-sided adhesive tape 10. Note that the aluminum foil 8 is not necessarily required.

In the manufacture of the heat insulating material 1, the heat insulating material main body 2 is formed into a predetermined shape by an appropriate method among various methods such as injection molding, extrusion molding, foam molding and pressure molding. At that time, the material of the heat insulating material main body 2 and the hollow powder 3 are combined to form the heat insulating material 1 by mixing the hollow powder 3 into the molding pellets or mixing when the molding material is liquefied by heating and melting. I do. The mixing amount of the hollow powder 3 is
If it is too much, the heat insulation effect will be high, but if it is too much it will cause damage to the molding die during molding, so care must be taken,
5 to 40% by weight.

In forming the heat insulating material 1 as in the first example, the thicker the heat insulating material 1 is, the higher the heat insulating effect becomes.
It is desirable to set it to about 6.0 mm. It should be noted that a portion having a thickness other than this may be partially present. In the case of foaming and molding as in the third and fourth examples,
It is preferable that the thickness be 1.5 mm or more from the viewpoint of shape retention. It is preferable that the material thickness be smaller than the value shown here because the content of the hollow powder 3 is reduced and the hollow powder 3 is hardly contained in a layered manner.

Further, regardless of the above-described method, as in the second example, the substrate material 5 formed by molding a resin material or a metal material is used.
Is coated with a resin paint such as acrylic, silicone, or fluororesin containing 5 to 40% by weight of the hollow powder 3 by painting or silk printing, and then heated and dried to form a heat insulating layer 6. Is also good. In addition, hollow powder 3
A method may be used in which a heat insulating material, which becomes the heat insulating layer 6 in which the heat insulating layer 6 is mixed in the resin material, is bonded and bonded with a double-sided tape or the like.

Next, an example of a jar rice cooker as a cooking container, which is a device (heating device) for boiling water and keeping heat using the heat insulating material 1, will be described with reference to FIGS. In FIG. 5 showing the entire cross-sectional view, 21 is a rice cooker main body, 22 is an outer frame forming an outer shell of the rice cooker main body 21, and a bottom plate 23 is fitted to an open bottom lower end of the outer frame 22. Fixed. Also, inside the outer frame 22 is an inner frame that is
24 are arranged. The inner frame 24 is formed by joining an inner frame upper portion 25 integral with the outer frame 22 and an inner frame lower portion 26 which is a separate component from the outer frame 22. A pot 27, which is a bottomed cylindrical container that accommodates rice to be cooked such as rice and water during rice cooking and accommodates a substance to be warmed such as rice during heat retention, can be inserted and removed inside the inner frame 24. To be housed. Further, an inner frame heat insulating plate 28 made of the heat insulating material 1 is provided on an outer surface of the upper portion 25 of the inner frame located around the pot 27.

The pot 27 has a pot main body 31 mainly made of a material having good heat conductivity such as aluminum, and is joined to a bottom surface and a lower part of a side surface of the pot main body 31, and is made of a magnetic material such as ferritic stainless steel. The heating layer 32 is a heating element made of a metal material. Further, a pot heat insulating layer 33 made of the heat insulating material 1 is provided on an outer surface of the pot 27. The pot insulation layer 33 may be a resin coating layer made of a resin coating containing a predetermined amount of a hollow member such as the hollow powder 3. The main component of the resin coating layer as the heat insulating material is preferably a material having non-adhesion after coating, such as a silicone resin or a fluorine resin. The pan insulation layer 33 is also provided on the outer surface of the heating layer 32,
It has the effect of insulating the 32 and increasing the efficiency of heating the pot 27.
In addition, a pot inner layer 34 made of austenitic stainless steel such as SUS304 selected from a material harder than the pot main body 31 is joined to at least the inner surface of the portion of the pot 27 where the cooked material or the heat-retained material contacts. You.

When the pot 27 is accommodated in the inner frame 24, the pot 27 is supported by the inner frame 24 at the upper end, and between the outer surface of the pot 27 and the inner surface of the inner frame 24 at a portion other than the upper end of the pot 27. A gap 36 is formed in the gap. The smaller the gap 36 is, the more preferably the heat transfer of the pot 27 is suppressed. Further, a pot temperature sensor 37, which is a pot temperature detecting means provided at the center of the bottom of the inner frame lower portion 26, has a structure in contact with the outer bottom surface of the pot 27 in which the pot insulation layer 33 is not formed. In addition, the temperature of the rice 27 or the object to be heated or kept in the pan 27 is detected at all times.

Reference numeral 41 denotes a heating coil as heating means provided on the outer surface of the inner frame 24, corresponding to the heat generating layer 32 on the outer surface of the pot 27. The heating coil 41 is formed by spirally winding a twisted litz wire formed by gathering conductive wires insulated with polyurethane, and held by the coil base 42, while holding the lower portion of the inner frame.
It is attached and fixed to the lower surface of 26. At a position below the coil base 42 in the outer frame 22, a power supply board 43 constituting a power supply circuit and a heating control board 44 constituting a control circuit of the heating coil 41 are provided. The heating control board 44 includes an inverter circuit and supplies a high-frequency current of 24 to 30 kHz to the heating coil 41. The supply of the high-frequency current generates a magnetic field in the heating coil 41, and the
The configuration in which the heating layer 32 is heated by electromagnetic induction heating to heat the pot 27 is the same as a conventionally known electromagnetic induction heating type insulated pot.

On the heating control board 44, a switching element 45 as a heat-generating component for generating the high-frequency current is provided with a radiator 46 mounted thereon. The heating control board 44 is provided with a board temperature sensor 47. An operation panel 49 holding an operation board 48 is provided on the upper side surface of the outer frame 22. Here, a plurality of operation switches 50 as operation means shown in FIG. A display device 51 such as an LED is provided.

Reference numeral 61 denotes a lid provided on the upper side of the rice cooker main body 21 so as to be rotatable and openable. The lid 61 is made of a polypropylene outer lid 62 which is the upper part of the lid 61 and is also made of polypropylene. A frame-shaped outer lid cover 63 fixed to the lower peripheral portion of the outer lid 62, and an inner lid 64 made of a material such as aluminum or stainless steel that covers an opening inside the outer lid cover 63. This inner lid 64 forms the lower surface of the lid 61,
27 directly covers the upper opening.

The inner lid 64 forming the lower surface of the lid 61 is provided with a lid reinforcing plate 65 fixed above the outer lid cover 63 located above the inner lid 64.
And an inner lid holding portion protrudingly formed on the inner peripheral surface of the outer lid cover 63.
66 and the peripheral part is inserted and held, and the outer lid cover 63
Can move up and down within a predetermined range. A packing 67 made of an annular elastic material is sandwiched between the peripheral portion of the lid reinforcing plate 65 and the peripheral portion of the
Another annular packing 69 is also sandwiched between the central concave portion 68 and the central portion of the inner lid 64. These packings 67, 69
Both seal the inner lid 64 and the other members constituting the lid 61, but the packings 67 and 69 are made of an elastic member such as silicone rubber. To be displaced. The inner lid 64 has an elastic force acting downward at all times by a spring 70 mounted between the inner lid 64 and the lid reinforcing plate 65. When the lid 61 is closed, the outer peripheral portion of the inner lid 44 is closed. The lower surface is configured to be elastically pressed against the upper surface of the upper peripheral edge of the pot 27 so as to make contact therewith. this is,
This is for improving the adhesion of the inner lid 64 to the pot 27.

A cover heat insulating plate 71 made of the heat insulating material 1 and a cover temperature sensor 72 as a cover temperature detecting means for detecting the lower surface temperature of the inner cover 64, that is, the cover 61, are provided on the upper surface, that is, the back surface of the inner cover 64, respectively. Can be The lid heat insulating plate 71 has a lid heater 73 formed of a cord heater as a heating means for heating the inner lid 64 during the heat retention on the lower surface. The lid heater 73 corresponds to the heating element 9 of the heat insulating material 1 of the fourth example shown in FIG. The lid heater 73 may be bonded to the inner lid 64 with a double-sided adhesive tape by bonding or the like, and may be covered from the outside with the lid heat insulating plate 71 made of the heat insulating material 1 of the first to third examples. Good.

The central recess 68 of the outer lid 62 has an inner lid
A steam port 75 having a plurality of steam holes 74 is provided at 64.
The steam port 75 has a configuration in which steam in the pot 27 is released to the outside of the lid body 61 during rice cooking, and specifically, a bottomed cylinder having a steam port locking portion 76 formed on the lower surface thereof. Shaped steam port body 77,
A steam port cap 78 for closing the upper opening of the steam port body 77 is provided. Further, a plurality of steam discharge ports 79 are formed in the steam port cap 78 exposed on the upper surface of the lid 61.
The steam port main body 77 is fixed to the outer lid 62 in a state in which the steam port locking portion 76 is engaged with the receiving portion 80 formed on the inner peripheral portion of the packing 69, and the packing 69 maintains airtightness. Therefore, it is in close contact with the upper surface of the inner lid 64 surrounding the steam hole 74. In addition, the steam port main body 77 is provided with a return hole 81 for collecting the oneva collected in the steam port main body 77 to the pot 27 side.

Here, the inner frame heat insulating plate 28, the pot heat insulating layer 33, and the lid heat insulating plate 71 will be additionally explained. The heat insulating material body 2 constituting these components does not require flame retardancy unless there is a heating element in the vicinity, and a resin material having heat resistance enough to withstand the operating temperature may be selected. Flame retardancy is also required. For example, the temperature of the lid heater 73 in the lid 61 is about 100 to 140 ° C. during cooking rice, and about 60 to 80 ° C. when keeping warm,
It has a higher heat-resistant temperature than the operating temperature of the lid heater 73,
In addition, in order to prevent combustion when the lid heater 73 generates abnormal heat, the heat insulating material 1 in which the hollow powder 3 is mixed into the heat insulating material body 2 made of flame-retardant silicone rubber is used as the cover heat insulating plate.
Used as 71. In addition, in the rice cooker of the present embodiment, since there is no heating element on the side surface of the inner frame 24, the flame retardancy of the inner frame heat insulating plate 28 is not necessarily required. When a heating element is provided on the side surface, flame retardancy is also required. Further, since the pan insulation layer 33 directly covers the heat generation layer 32 of the pan 27, high heat resistance and flame retardancy are required.

FIG. 6 shows an outline of the electrical configuration in this embodiment. In the figure, a microcomputer 91 inputs signals from an operation switch 50 provided on the operation panel 49 and signals from the temperature sensors 37, 47, and 72, and based on the signals, an IH drive circuit 92 on the heating control board 44. And the high-frequency current generating means 93 to control the output and power cutoff of the heating coil 41, and to control the power cutoff of the lid heater 73 through the heater drive circuit 94 and the power cutoff means 95, and to display The display operation of the display device 51 provided on the operation panel 49 is controlled via the means driving circuit 96.

Next, the heating control during cooking and keeping the temperature warm will be described with reference to the graph of FIG. The solid line graph at the top of the figure shows the detected temperature of the pot temperature sensor 37, and the dotted line graph at the top of the figure shows the lid temperature sensor.
72 shows the detected temperature. The middle graph in the figure shows the timing and output of energization of the heating coil 41, and the lower graph in the same figure shows the timing and output of energization of the lid heater 73. In the middle and lower graphs in the figure, the hatched portions indicate the energization timing. At the time of cooking rice, a cooking process, a boiling heating process, a boiling continuation process, a cooking process and a spotting process are sequentially performed. Hereinafter, the control of these steps will be described, but the numerical values and time specifically exemplified vary according to the rice cooking course, the product, and the like.

In the cooking process, the output of the induction heating of the pot 27 is made relatively low, and the water temperature in the pot 27 is heated to a high temperature of 60 ° C. or less to promote the water absorption of the rice. Done. After the end of the cooking process, the process moves to the boiling heating process. The boiling heating step is a step of boiling water in the pan 27, and continuous heating is performed by the maximum heating amount of the heating coil 41. Then, during the boiling heating process, the lid temperature sensor 72
When the temperature becomes equal to or higher than ℃ and the temperature change stabilizes at a predetermined temperature gradient, the process shifts to a boiling continuation process. In this boiling continuation process, while reducing the induction heating output of the pot 27 slightly,
By performing the predetermined intermittent energization, the heating amount is such that the boiling state of the water in the pan 27 continues for about 1 to 7 minutes. Thereafter, in order to prevent dew condensation on the inner lid 64 constituting the lower surface of the lid 61, the lid heater 73 (output 50W) is turned off. Then, when a predetermined stroke time elapses or when the temperature of the pot temperature sensor 37 rises by 2 to 5 ° C., the boiling continuation process ends, and the process shifts to a cooking process. In this cooking process, the output of the induction heating of the pot 27 is maximized, and intermittent energization is performed. And the temperature of the pot temperature sensor 37 is 10-15
When the temperature rises by ℃, the cooking process ends, and the process shifts to the spotting process. In this spotting process, the output of the induction heating of the pot 27 is relatively low, and the heating is performed according to the temperature of the pot temperature sensor 37 so that the cooked rice in the pot 27 is not scorched.
The inside of the pot 27 is kept at a high temperature to secure the spotting effect. Then, for example, when a predetermined stroke time elapses, the swing stroke ends, and the process shifts to a warming stroke. In this warming process, heating is performed with a low heating amount according to the temperature detected by the pan temperature sensor 37, and the rice in the pan 27 is maintained at a predetermined temperature. Also the inner lid
In order to prevent dew condensation on the heater 64, power is cut off through the lid heater 73 based on the temperature detected by the lid temperature sensor 72.

The heat insulating material body 2 formed by molding a plastic resin as described above is inferior in heat resistance and hardness to glass fiber, ceramic fiber, and ceramic powder conventionally used as a heat insulating material. There is an advantage that fibers and powder are not scattered at all. Therefore, it is possible to prevent the working environment from being deteriorated during manufacturing, to facilitate the handling of the heat insulating material 1, and to improve the assemblability. Further, since it is not necessary to use an adhesive when manufacturing the heat insulating material 1, there is no generation of odor of the adhesive, and the working environment can be further improved.

Glass and ceramics have a high specific gravity if they are fibrous or solid granular, and cannot be improved in heat resistance even if they are contained in a molded article of plastic resin. By making the hollow powder 3, the specific gravity becomes low, the thermal conductivity becomes small, and a high heat insulating effect can be obtained. In addition, since a large number of fine hollow powders 3 are contained in the heat insulating material body 2, the hollow portions 4 can be formed in layers inside the heat insulating material body 2, so that the heat insulating performance can be further improved. Further, the third type shown in FIG.
As in the example and the fourth example shown in FIG. 4, in addition to the hollow powder 3,
If the heat insulating material main body 2 is also made of a foam or the like and has a hollow portion 7 forming an air layer inside, the heat insulating performance can be synergistically improved. In addition, since the heat insulating material 1 has independent hollow portions 4 and 7, there is no fear of moisture absorption when the heat insulating material 1 is incorporated in a device such as a rice cooker. Note that the hollow portion 7 is provided in the heat insulating material body 2.
Providing the above also has the effect of reducing the amount of resin material used to form the heat insulating material body 2 and improving economic efficiency.

The hollow portion 7 formed directly in the heat insulating material body 2 made of a resin material is crushed and cannot hold its shape because the material is soft if the inside is to be decompressed or almost evacuated. Since ceramics and ceramics are highly rigid, they can be maintained in shape without being crushed even if the inside is hollowed and reduced or almost vacuumed. The shape of the entire heat insulating material 1 can be maintained in a free shape. By reducing or substantially reducing the pressure in the hollow portion 4 as described above, the heat insulation performance can be further improved.

When the heat insulating material body 2 into which the hollow powder 3 is mixed is formed into a predetermined shape by, for example, injection molding of a thermoplastic resin, the hollow powder 3 made of glass or ceramic is used.
Is harder than the material of the heat insulating material body 2 and, because of its fine particle size, does not easily collapse even when pressure is applied. At the same time, since the melting temperature of the hollow powder 3 made of glass or ceramics is much higher than that of the silicone resin or polypropylene that is the material of the heat insulating material main body 2, the heat generated when the material of the heat insulating material main body 2 is melted is used. Are not melted together and the hollow portion 4 disappears. As a result, the heat insulating material 1 made of a resin molded article having a low hardness and having a high heat insulating effect can be obtained.

The heat insulating material 1 can be easily formed into a free shape with almost no restrictions by various forming methods.
For example, even after molding using a mold, since the heat insulating material body 2 is made of a low-hardness resin material, the heat insulating material main body 2 can be freely subjected to secondary processing. That is, the present heat insulating material 1 can be formed into a free shape suitable for its structure when incorporated into a device, and can be incorporated even in a three-dimensional shape in which the accommodation space of the heat insulating material 1 in the device is relatively complicated. . In addition, it is not necessary to form a space for accommodating the heat insulating material in the device as in the related art, and the heat insulating material 1 can be incorporated in the minimum space in the device. Can be

If the low-hardness resin material used as the heat insulating material body 2 is used as a paint for coating, the paint is mixed with a hollow member such as the hollow powder 3 for coating or printing.
The range of use is further expanded.

In a rice cooker incorporating such a heat insulating material 1, the heat insulating efficiency of the heat insulating material 1 is high, so that the heating efficiency at the time of heating rice and the heat insulating efficiency at the time of heat keeping are high, and the consumption at that time is high. The amount of electric power can be reduced as compared with the conventional case, energy can be saved during cooking, and the economic efficiency is improved. In addition, cooking time can be reduced. That is, as in the rice cooker of the above embodiment, a heating layer which is a heating element for electromagnetic induction heating of the pan 27
A pot insulation layer 32 made of the present heat insulating material 1 is disposed outside the lid 32, and a lid is provided.
By disposing the lid heat insulating plate 71 made of the present heat insulating material 1 outside the lid heater 73 which is the heating element of 61, the pot main body 31 and the inner lid 64 on the heated side without the heat insulating material 1 can be more efficiently used than before. Can be heated. Further, for example, if the lid heater 73 is previously joined to one surface of the lid heat insulating plate 71, the lid heat insulating plate 71 and the lid heater 73 can be attached at the same time, and the assembling property is improved. In addition, the lid reinforcing plate 65
Is formed as a partition plate member that forms a double space in the lid 61, and its outer surface (on the side opposite to the heater 73) is coated with a paint mixed with a hollow member such as the hollow powder 3, thereby greatly improving heat insulation. The heat retention of the lid 61 can be improved. In addition, by disposing the pot insulation layer 32 and the inner frame insulation plate 28 made of the present heat insulating material 1 around the pot 27 which is a container, it is possible to suppress the heat of the pot 27 from escaping to the outside, so that the pot 27 27 heat retention is improved.

Further, since the temperature rise on the outer surface of the pot 27 is suppressed, the danger of burns when the outer surface of the pot 27 is touched by hand is reduced, and the safety is enhanced and the container is easily carried. Thus, a highly practical cooking container can be provided.

Further, since the pot insulation layer 33 composed of a resin coating layer contains the hollow powder 3, the pot insulation layer 33 is formed.
Even if the surface of 33 has irregularities in granular form, this pot insulation layer 33
Is made of a non-adhesive material, it is possible to prevent the adhesion of dirt to the surface of the pan insulation layer 33, and to easily clean even if dirty. Therefore, the pan insulation layer
It is possible to prevent inconvenience such that the practicality is reduced due to the mixing of the hollow powder 3 into 33.

Further, since the heat insulating material 1 can be manufactured simply by mixing the hollow powder 3 with the resin material as described above, it can be manufactured easily and inexpensively.

By the way, if the heat insulating material main body 2 itself into which the hollow powder 3 is mixed is used as the heat insulating material 1, the hollow powder 3 can be arranged over almost the entire heat insulating material 1. The hollow powder 3 is disposed up to this point, which may waste economically. Therefore, in such a case, as in the second example shown in FIG. 2, a heat insulating layer made of the heat insulating material main body 2 in which the hollow powder 3 is mixed only in a necessary portion of the surface of the substrate material 5 made of a resin material or the like. 6 may be formed by bonding or coating. Thereby, the heat insulating layer 6 having the heat insulating effect can be arranged only in the portion where the heat insulating is required, and the heat insulating effect can be obtained economically without insulating the unnecessary portion.

Note that the present invention is not limited to the above-described embodiment, and various modifications can be made. For example,
In the rice cooker of the above embodiment, a lid heater comprising an electric heater
Although the inner lid 64 constituting the lower surface of the lid 61 was heated by 73, even if the lower surface of the lid is heated by electromagnetic induction heating, only the lower surface plate of the lid becomes a heating element,
Similarly, the heat insulating material of the present invention can be used. Further, in the rice cooker of the above embodiment, the pot 27 as a container is heated by electromagnetic induction, but the pot may be heated by an electric heater. Further, the heat insulating material of the present invention, besides a rice cooker,
It can be applied to cooking containers that are various types of heating equipment that keeps warm water such as electric water heaters. For example, in a device such as an electric water heater in which a container for storing an object to be heated such as water is fixed to the main body, a heat insulating material may be provided directly around the container. And since the heat insulating performance of the heat insulating material is high, it is possible to reduce the power consumption required for the water heater and to shorten the boiling time.

[0064]

According to the first aspect of the present invention, since the heat insulating material is a combination of a member having a low hardness and a member having a higher hardness than the member and having a hollow inside, the heat insulating material has a high heat insulating performance and is easy to assemble. And an inexpensive heat insulating material for a cooking container can be provided. In addition, since the heat insulating material can be formed into an appropriate shape according to the cooking container by a low-hardness member, assemblability is further improved, while a hollow member having a high hardness is not crushed by the molding, Insulation performance can be maintained.

According to the second aspect of the present invention, a member having a lower specific gravity by foaming a resin material such as a silicone resin or a polypropylene is provided with a member having a higher melting temperature and a higher hardness than the resin material and having a hollow inside. Since the heat insulating material is contained, it is possible to provide an inexpensive heat insulating material for a cooking container, which has extremely high heat insulating performance, is excellent in assemblability, and is inexpensive. In addition, since the hollow portion can be mixed with the melted resin material and molded without mixing the hollow portion, the heat insulating material can be molded into an appropriate shape according to the cooking container, and the assembling property can be improved. Even better.

According to the third aspect of the present invention, a low-hardness member made of a resin material such as a silicone resin or a polypropylene, and a harder member made of a material such as glass or ceramics that is harder than the resin material and has a hollow interior, Since the heat insulating material is formed by combining a member with a vacuum, it is possible to provide an inexpensive heat insulating material for a cooking container which has high heat insulating performance, is excellent in assemblability and is inexpensive. In addition, since the heat insulating material can be formed into a shape suitable for the cooking container by using a low-hardness member made of a resin material, assemblability is further improved. In addition to maintaining the heat insulation performance, the inside of the hollow member can be decompressed or almost evacuated. Thereby, the heat insulation performance can be further improved.

According to the fourth aspect of the present invention, since a heat insulating material containing a plurality of fine powders made of glass or ceramic and having a hollow inside is contained in a plastic resin such as a fluorine resin, a polypropylene, or a silicone resin. It is possible to provide an inexpensive heat insulating material for a cooking vessel that has high performance and excellent assemblability. Also, since the fine powder can be mixed with the melted plastic resin and molded without losing the hollow portion in the fine powder, the heat insulating material can be molded into an appropriate shape according to the cooking container, and the assembling property can be improved. Even better.

According to the fifth aspect of the present invention, since a heat insulating material is formed by joining or coating a layer made of glass or ceramic powder and including a hollow member, on the surface of the member forming the heat insulating structure. It is possible to provide an inexpensive heat insulating material for a cooking container which has excellent assemblability and is inexpensive. In addition, since the heat insulating layer can be formed only on necessary portions of the members forming the heat insulating structure, the cost is further increased.

According to the cooking container of the sixth aspect of the present invention, a flame-retardant plastic resin having a heat-resistant temperature higher than the operating temperature of the heating element is made of a hard material having a melting temperature higher than that of the plastic resin and the inside is hollow. Since the heat-insulating material in which the above-mentioned members are mixed is disposed outside the heating element, it is possible to provide an inexpensive cooking container having high heating efficiency, excellent assemblability, and excellent in assemblability. In particular, since the heat insulating material can be formed by mixing the melted plastic resin with the hollow member, without losing the hollow portion, the heat insulating material can be formed into an appropriate shape according to the cooking container, The assemblability can be further improved.

According to the cooking container of the seventh aspect of the present invention, in addition to the effect of the sixth aspect of the present invention, the heating element is joined to one surface of the heat insulating material, so that the heating efficiency and the heat retaining efficiency can be further improved. Also, assemblability can be further improved.

According to the cooking container of the present invention, the dissolving temperature is higher and higher than that of the plastic resin in a plastic resin such as a fluororesin or a silicone resin having a heat-resistant temperature higher than the container temperature when the container is heated. Since a heat insulating material made of a material of hardness and mixed with a member having a hollow inside is arranged around the container, it is possible to provide an inexpensive cooking container having high heat retention efficiency, excellent assemblability, and excellent in assemblability. In particular, the heat insulating material does not lose the hollow part,
Since it is possible to mix a melted plastic resin with a member having a hollow interior, it is possible to mold the heat insulating material into an appropriate shape according to the cooking container, and to further improve the assemblability.

According to the cooking container of the ninth aspect, in addition to the effect of the sixth or seventh aspect, the plastic resin is formed of a foam, so that the heat insulation performance can be further improved, and the cooking container can be improved. Heating efficiency and heat retention efficiency can be further improved.

According to a tenth aspect of the present invention, there is provided a cooking container, wherein the container is provided with a magnetic metal material, and a resin coating layer including a hollow member is formed on an outer surface of the container containing the magnetic metal material. Since the magnetic metal material is heated by the heating coil for electromagnetic induction heating provided outside the container to heat the container, it is possible to provide an inexpensive cooking container having high heating efficiency, excellent assemblability, and excellent in assemblability. . Also,
By suppressing the rise in temperature on the outer surface of the container, the risk of burns when touching the outer surface of the container with hands is reduced, and the safety is improved, and the container is easy to carry. Can be provided.

According to the cooking container of the eleventh aspect, in addition to the effect of the tenth aspect, the resin coating layer is mainly made of a non-tacky material such as a silicone resin or a fluorine resin after coating. Since the internal hollow member is contained, even if the surface of the resin coating layer has irregularities in a granular manner, the main body of the resin coating layer is made of a material having non-adhesiveness. In addition to preventing dirt from adhering to the surface of the resin coating layer, even if it becomes dirty, it can be easily cleaned, and the inconvenience that the practicality is reduced due to the mixing of a member having a hollow inside can be prevented.

[Brief description of the drawings]

FIG. 1 is an embodiment (first example) of a heat insulating material for a cooking container of the present invention.
FIG.

FIG. 2 is an embodiment (second example) of the heat insulating material for a cooking container of the present invention.
FIG.

FIG. 3 is an embodiment (third example) of a heat insulating material for a cooking container of the present invention.
FIG.

FIG. 4 is an embodiment (fourth example) of the heat insulating material for a cooking container of the present invention.
FIG.

FIG. 5 is a sectional view of a jar rice cooker showing one embodiment of the cooking container of the present invention.

FIG. 6 is a block diagram showing an electrical configuration of the same.

FIG. 7 is a graph showing the timing of heating and the change over time in temperature.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 heat insulating material 2 heat insulating material body (low-hardness member, plastic resin, resin material) 3 hollow powder (high-hardness hollow member, fine powder) 5 substrate material (member forming heat insulating structure) 9 heating element 27 Pot (container) 28 Inner frame heat insulating plate (heat insulating material) 32 Heat generation layer (heating element, magnetic metal material) 33 Pot heat insulating layer (heat insulating material, resin coating layer) 41 Heating coil 71 Lid heat insulating plate (heat insulating material) 73 Lid Heater (heating element)

Claims (11)

[Claims] 1. A heat insulating material for a cooking container, comprising a member having a low hardness and a member having a higher hardness than the member and having a hollow inside. 2. A member obtained by lowering the specific gravity of a resin material such as silicone resin or polypropylene by foaming or the like, wherein a member having a higher melting temperature, a higher hardness and a hollow inside is contained. Insulation for cooking vessels. 3. A combination of a low-hardness member made of a resin material such as silicone resin or polypropylene, and a member made of glass or ceramic or the like and having a hardness higher than that of the resin material and having a hollow interior and a reduced pressure or almost a vacuum. A heat insulating material for a cooking container, comprising: 4. A heat insulating material for a cooking vessel, wherein a plurality of fine powders made of glass or ceramics and having a hollow inside are contained in a plastic resin such as a fluorine resin, a polypropylene or a silicone resin. 5. A heat insulating material for a cooking vessel, wherein a layer including a member made of glass or ceramic powder and having a hollow inside is joined or coated on a surface of a member forming a heat insulating structure. 6. A heat insulating material comprising a flame-retardant plastic resin having a heat-resistant temperature higher than the operating temperature of a heating element, mixed with a member made of a material having a higher melting temperature and a higher hardness than the plastic resin and having a hollow inside. Is disposed outside the heating element. 7. The cooking container according to claim 6, wherein said heat generating element is joined to one side of said heat insulating material. 8. A plastic resin, such as a fluororesin or a silicone resin, having a higher heat-resistant temperature than the temperature of the container when the container is heated, is made of a material having a higher melting temperature and a higher hardness than the plastic resin, and has a hollow interior. A cooking container, wherein a heat insulating material mixed with members is disposed around the container. 9. The cooking container according to claim 6, wherein the plastic resin is formed of a foam. 10. A container provided with a magnetic metal material, a resin coating layer including a member having a hollow inside formed on an outer surface of the container containing the magnetic metal material, and electromagnetic induction heating provided outside the container. A heating coil for heating the magnetic metal material to heat the container. 11. The resin coating layer is mainly made of a non-tacky material such as a silicone resin or a fluorine resin after coating, and contains a member having a hollow inside. Cooking container.