JP2005058644A - Electric kettle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To offer an electric kettle which reduces that heat turns around the circumference of a vacuum insulation material, makes it hard for heat to be radiated to the outside, and has an improved hot preserving performance. <P>SOLUTION: This electric kettle has a container 3 which contains liquid 2, a heating means 5 which heats the liquid 2 within the container 3, an upper frame 4 holding the upper part opening circumference of the container 3, a lid body 6 covering the upper part opening of the receptacle, the vacuum insulation material 7, which is located in the circumference section of the container 3 and in which the inside of a surface structural 7a is made vacuum, and a body 1 located in the circumference section of the vacuum insulation material 7 and in the lower part of the upper frame, and an auxiliary heat insulating material 8 having a smaller heat conductivity than the surface structural 7a of the vacuum insulation material 7 is put between the vacuum insulation material 7 and the container 3. Thereby, heat conducted to the surface structural 7a of the vacuum insulation material 7 outside is reduced and heat radiation to the external world can be reduced. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an electric water heater with improved heat insulation performance of a water storage tank for storing a liquid.

  Conventionally, there has been a storage tank of this type of electric water heater that uses a vacuum heat insulating material for heat insulation (for example, see Patent Document 1).

  FIG. 6 shows a cross-sectional view of the electric water heater described in Patent Document 1. In FIG.

  As shown in FIG. 6, the electric water heater is a body 101 that constitutes the outer shell, a container 103 that accommodates the liquid 102 provided in the inside, and an upper part of the body 101, and the container 103 is placed in the central opening thereof. The upper frame 104 to be placed, the heating means 105 for heating and keeping the liquid 102 fixed to the bottom surface of the container 103, the lid 106 covering the upper opening of the container 103, the lower part of the upper frame 104 and the container The vacuum heat insulating material 107 is provided at a position of the outer peripheral portion of 103 and prevents heat transferred from the liquid 102 to the container 103 from being radiated to the outside. The vacuum heat insulating material 107 is composed of a surface member 107a and a core material 107b, and the inside is maintained in a vacuum state.

The operation of the above configuration will be described. The heat of the liquid 102 heated by the heating means 105 is transmitted to the container 103, the upper frame 104, and the lid 106, but heat radiation from the container through the body 101 to the outside is reduced by the vacuum heat insulating material 107. Moreover, the vacuum heat insulating material 107 played the role which the vacuum part of the core material 107b interrupted | blocked heat transfer, and was exhibiting the performance excellent in the heat | fever interruption | blocking to the normal line direction of the surface of the container 103.
JP-A-11-290210

  However, the surface member 107a of the vacuum heat insulating material 107 contains metal in order to ensure gas barrier properties and has a high thermal conductivity. In the conventional configuration, heat is transmitted to the surface of the container 102 and the tangential direction of the vacuum heat insulating material 107. There is a problem that heat is dissipated to the outside world due to heat flowing around the outer periphery of the vacuum heat insulating material 107 due to the heat conduction of the surface member 107, and the heat retaining performance is deteriorated.

  The present invention solves the above-described conventional problems, and an object thereof is to reduce heat dissipation due to heat flowing around the outer periphery of a vacuum heat insulating material and to improve heat insulating performance.

  In order to solve the above-described conventional problems, an electric water heater of the present invention includes a container for storing a liquid, a heating means for heating the liquid in the container, an upper frame for holding the outer periphery of the upper opening of the container, A lid that covers the upper opening of the container; a vacuum heat insulating material that is located on the outer periphery of the container and evacuates the inside of the surface member; and a body that is positioned on the outer periphery of the vacuum heat insulating material and the lower part of the upper frame The auxiliary heat insulating material having a smaller thermal conductivity than the surface member of the vacuum heat insulating material is sandwiched between the vacuum heat insulating material and the container, and the surface is suppressed by suppressing heat transfer from the container to the surface member of the vacuum heat insulating material. Heat leakage due to heat conduction of the member can be reduced.

  Further, the electric water heater of the present invention covers the outer periphery of the vacuum heat insulating material with an auxiliary heat insulating material, and makes the heat insulating material of the vacuum heat insulating material smaller than the heat conductivity of the vacuum heat insulating material. Heat transferred from the container side to the body side of the vacuum heat insulating material by the heat conduction of the surface member can reduce transmission to the atmosphere inside the body.

  The electric water heater of the present invention can reduce heat radiation due to heat flowing around the outer periphery of the vacuum heat insulating material, and can improve the heat insulating performance.

  According to a first aspect of the present invention, there is provided a body constituting an outer shell, an upper frame placed on an upper portion of the body, a container for storing a liquid placed in a central opening of the upper frame, and an upper opening of the liquid A lid for covering, a heating means for heating the liquid in the container, a vacuum heat insulating material in which the inside of the surface member provided between the container and the body is evacuated, and between the container and the vacuum heat insulating material The auxiliary heat insulating material has a heat conductivity smaller than the heat conductivity of the surface member of the vacuum heat insulating material.

  As a result, heat transfer from the container to the surface member of the vacuum heat insulating material can be suppressed, the amount of heat entering the outer peripheral surface of the vacuum heat insulating material by heat conduction of the surface member can be reduced, and the heat retaining performance can be improved.

  According to the second invention, in particular, the auxiliary heat insulating material of the first invention is sandwiched from the upper part of the outer periphery of the container to the lower end of the outer periphery of the container so that the container and the vacuum heat insulating material are not in direct contact with each other. The heat transfer to the surface member of the vacuum heat insulating material is suppressed, the amount of heat that the heat turns to the outer periphery of the vacuum heat insulating material can be reduced by the heat conduction of the surface members of the upper and lower ends of the vacuum heat insulating material, and the heat insulation performance can be improved. .

  According to the third invention, in particular, the auxiliary heat insulating material of the first invention is wound only on the lower side of the upper frame lower part of the outer periphery of the container, and the container and the vacuum heat insulating material are not directly touched at the upper part of the outer periphery of the container. The temperature of the upper part of the vacuum heat insulating material can be reduced. Therefore, the heat flux that flows from the inside to the outside of the upper part of the vacuum heat insulating material can be reduced, so that the heat retaining performance can be improved. In addition, the amount of auxiliary heat insulating material used can be reduced, which is economical.

  The fourth invention, in particular, by wrapping the auxiliary heat insulating material of the first invention only on the lower end of the vacuum heat insulating material on the outer periphery of the container, and by making the container and the vacuum heat insulating material not directly touched at the lower part of the outer periphery of the container, The temperature of the lower part of the vacuum heat insulating material can be reduced. Therefore, the heat flux that goes from the inside to the outside of the lower part of the vacuum heat insulating material can be reduced, so that the heat retaining performance can be improved. In addition, the amount of auxiliary heat insulating material used can be reduced, which is economical.

  In the fifth aspect of the invention, in particular, in the configuration of the first aspect of the invention, the auxiliary heat insulating material covers the entire surface of the vacuum heat insulating material so that the container, the vacuum heat insulating material, the vacuum heat insulating material, and the atmosphere inside the body are not in direct contact with each other. The configuration was As a result, the amount of heat that flows to the body side due to the heat conduction of the upper and lower surface members of the heat insulating material is reduced, and the amount of heat that has flowed to the outside of the vacuum heat insulating material through the surface member is transmitted to the atmosphere inside the body. As a result, the heat retention performance can be improved.

  According to a sixth aspect of the present invention, there is provided a body constituting an outer shell, an upper frame placed on an upper portion of the body, a container for storing a liquid placed in a central opening of the upper frame, and an upper opening of the liquid A heating means for heating the liquid in the container, a cover for covering, a vacuum heat insulating material provided between the container and the body, and an auxiliary heat insulating material for covering an outer peripheral portion of the vacuum heat insulating material, and the auxiliary heat insulating material. The material had a thermal conductivity smaller than that of the vacuum heat insulating material.

  As a result, the heat conducted from the container side of the vacuum heat insulating material to the body side due to the heat conduction of the surface member of the vacuum heat insulating material can reduce the transfer to the atmosphere inside the body, and as a result, the heat retaining performance can be improved. Can do.

  In the seventh invention, in particular, by making the auxiliary heat insulating material of any one of the first to fourth or sixth inventions into a cylindrical shape, the joint of the auxiliary heat insulating material is eliminated, and the heat retaining performance can be improved. it can.

  In the eighth invention, in particular, the auxiliary heat insulating material according to any one of the first to fourth or sixth inventions is fixed to the vacuum heat insulating material, whereby a gap between the auxiliary heat insulating material and the vacuum heat insulating material is formed. Since air convection can be prevented and heat resistance can be increased, heat retention performance can be improved. In addition, assembly can be improved.

  In the ninth invention, in particular, the auxiliary heat insulating material according to any one of the first to fourth or sixth inventions is fixed to the container, thereby eliminating the gap between the container and the auxiliary heat insulating material, and maintaining the heat retaining performance. It is possible to improve and improve assemblability.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 shows a cross-sectional view of an electric water heater according to the first embodiment of the present invention.

  In FIG. 1, an electric water heater is a body 1 that constitutes an outer shell, a container 3 that accommodates a liquid 2 provided therein, a top of the body 1, and a container 3 that is placed in the central opening. A frame, a heating means 5 for heating and keeping the liquid 2 provided at the bottom of the container 3, a lid 6 for covering the upper surface opening of the container 3, and between the body 1 and the container 3 and on the lower part 4a of the upper frame A vacuum heat insulating material 7 provided, and an auxiliary heat insulating material 8 such as a compressed melamine foam provided between the outer peripheral portion of the container 3 and the vacuum heat insulating material 7 are provided. Here, the vacuum heat insulating material 7 is comprised from the surface member 7a and the core material 7b, and the inside is made into the vacuum state. As the surface member 7a, a laminate film of resin and metal, for example, a laminate film composed of nylon, polyethylene terephthalate, aluminum foil, unstretched polypropylene, etc. is used, and as the core material, inorganic powder such as silica or pearlite, glass wool, etc. Inorganic fibers or inorganic or organic foams are used.

  In the present embodiment, since the container 3 is placed in the central opening of the upper frame 4, the upper end of the container 3 is configured to have an upper frame. Accordingly, the vacuum heat insulating material and the auxiliary heat insulating material are provided on the lower side of the upper frame lower portion 4a, which is the upper part of the outer periphery of the container. However, the structure is not limited to this structure, and depending on the structure, the structure is provided from the upper end of the container. Of course, it is good.

  About the electric water heater comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

Usually, the liquid 2 in the container 3 made of a stainless steel plate or the like is heated by the heating element 5 to a high temperature and is kept in that state. The heat of the heat-retained liquid 2 is released to the outside from all paths. Among these, since the heat radiation from the outer peripheral side of the container 3 is the largest, the heat radiation is suppressed by using the vacuum heat insulating material 7 having a good heat insulation performance. However, since the container 3 and the vacuum heat insulating material 7 are in contact with each other in the conventional configuration, the heat of the container 3 is directly transferred to the surface member 7 a of the vacuum heat insulating material 7. However, the surface member 7a of the vacuum heat insulating material 7 needs to be made of a material having excellent gas barrier properties in order to maintain a vacuum, and therefore, a material containing a metal is generally used. Therefore, although the heat conductivity of the whole vacuum heat insulating material is about 8 × 10 ⁻³ W / mK and is relatively excellent in heat insulation, the heat conductivity of the surface member 7a covering the surface is as high as about 0.56 W / mK. The heat transmitted to the surface member 7a radiates from the upper and lower end portions of the vacuum heat insulating material 7 to the outer peripheral portion of the vacuum heat insulating material 7 due to the heat conduction of the surface member 7a. Therefore, in the present embodiment, as shown in FIG. 1, the auxiliary heat insulating material 8 having a thermal conductivity smaller than that of the surface member 7 a of the vacuum heat insulating material 7 is inserted between the container 3 and the vacuum heat insulating material 7. As a result, the amount of heat transmitted to the surface member 7a is reduced, and the temperature of the surface member 7a is reduced. Therefore, the amount of heat that flows around the surface member 7a can be reduced and the heat insulation performance can be improved.

  Moreover, as an effect when the size of the auxiliary heat insulating material 8 is set to the same size as the outer periphery of the container, for example, a compressed melamine foam as an auxiliary heat insulating material 8 around the entire periphery between the vacuum heat insulating material 7 and the container 3. When wound (thermal conductivity: 0.032 W / mK), the thermal insulation performance was improved by about 5%. By making the auxiliary heat insulating material 8 larger than the vacuum heat insulating material 7, the heat insulating performance can be further improved.

  Moreover, although the vacuum heat insulating material 7 was described as an example in the present embodiment, the same effect is not limited to the vacuum heat insulating material as long as the heat insulating material is formed of the core material 7b and the surface member 7a and the surface member 7a has high thermal conductivity. Is obtained.

  As described above, by providing the auxiliary heat insulating material 8 between the container 3 and the vacuum heat insulating material 7, the heat retaining performance can be improved.

  In addition, although the case where the melamine foam was used as the auxiliary heat insulating material 8 was demonstrated, the auxiliary heat insulating material 8 is not limited to a compression melamine foam, What kind of form will be if heat conductivity is smaller than the surface member 7a? For example, ceramic wool, glass wool, or a fibrous heat insulating material may be used.

(Embodiment 2)
2 and 3 are cross-sectional views of an electric water heater according to the second embodiment of the present invention. Since the basic configuration of the present embodiment is the same as that of the first embodiment, different points will be mainly described. The same functions as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  The present embodiment is different from the first embodiment in that the auxiliary heat insulating material is provided over the entire space between the vacuum heat insulating material 7 and the container 3 in the first embodiment, whereas in the present embodiment, The auxiliary heat insulating material is provided in the upper part or the lower part, which is a part between the vacuum heat insulating material 7 and the container 3, so that the container and the vacuum heat insulating material are not in direct contact with each other. Hereinafter, it demonstrates using drawing.

  As shown in FIG. 2, the auxiliary heat insulating material 8 is sandwiched only between the vacuum heat insulating material 7 and the container 3. As shown in FIG. 2, since the upper part has an upper frame lower part, this part is not provided with a heat insulating material. In this configuration, since the container 3 and the vacuum heat insulating material 7 are not in contact with each other, heat conduction from the container 3 to the vacuum heat insulating material 7 is eliminated. The heat transfer of the vacuum heat insulating material 7 flows from the high temperature container 3 side to the low temperature side body 1 side. Since this mainly occurs through the end face of the surface member 7a, the heat flux of the vacuum heat insulating material increases at the upper and lower ends. Therefore, the auxiliary heat insulating material 8 is not wound around the center of the outer periphery of the container, and the heat transfer from the upper container 3 to the vacuum heat insulating material is reduced even if only the upper part is formed, so the temperature of the upper surface member 7a of the vacuum heat insulating material is lowered. A heat flux becomes small and can insulate heat insulation. However, in this case, a large gap is formed between the container 3 portion below the center and the vacuum heat insulating material 7, and the auxiliary heat insulating material 8 is as much as possible so that heat transfer does not occur between the container 3 and the vacuum heat insulating material 7 due to convection. It is better to use a thin one. According to the experimental results, the auxiliary heat insulating material 8 is desirably 10 mm or less.

  Moreover, the same effect is acquired even if it winds the auxiliary heat insulating material 8 only to a lower end like FIG. Furthermore, you may wind the auxiliary heat insulating material 8 to an upper part and a lower end part simultaneously. In this case, the auxiliary heat insulating material 8 may be another type.

  As described above, the auxiliary heat insulating material 8 sandwiched between the container 3 and the vacuum heat insulating material 7 is only the upper end or only the lower end of the outer periphery of the container 3, thereby improving the heat insulating performance and further reducing the material cost of the auxiliary heat insulating material. Can be reduced.

(Embodiment 3)
FIG. 4 is a cross-sectional view of an electric water heater according to the third embodiment of the present invention. Since the basic configuration of the present embodiment is the same as that of the first embodiment, different points will be mainly described. The same functions as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  The present embodiment is different from the first embodiment in that the auxiliary heat insulating material is provided over the entire space between the vacuum heat insulating material 7 and the container 3 in the first embodiment, whereas in the present embodiment, It is the point which provided the auxiliary heat insulating material over the whole vacuum heat insulating material. Hereinafter, it demonstrates using drawing.

  As shown in FIG. 4, the auxiliary heat insulating material 8 is wound around the entire outer periphery of the vacuum heat insulating material 7 to reduce heat transferred from the container 3 to the surface member 7 a of the vacuum heat insulating material 7, and escape around the surface member to the outside. It is possible to reduce the transfer of heat to the atmosphere inside the body 1. For example, when a compressed melamine foam (thermal conductivity: 0.032 W / mK, t = 2 mm) was wound around the entire surface of the vacuum heat insulating material 7, the heat retention performance was improved by about 8%.

  As described above, the heat insulation performance can be improved by winding the auxiliary heat insulating material around the entire surface of the vacuum heat insulating material 7, that is, both the container 3 side and the body 1 side.

(Embodiment 4)
FIG. 5 is a cross-sectional view of an electric water heater according to the fourth embodiment of the present invention. Since the basic configuration of the present embodiment is the same as that of the first embodiment, different points will be mainly described. The same functions as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  The present embodiment is different from the first embodiment in that the auxiliary heat insulating material is provided over the entire space between the vacuum heat insulating material 7 and the container 3 in the first embodiment, whereas in the present embodiment, The auxiliary heat insulating material is provided on the body side. Hereinafter, it demonstrates using drawing.

  As shown in FIG. 5, the auxiliary heat insulating material 8 is wound around the outer periphery of the vacuum heat insulating material 7, i.e., the body 1 side, thereby suppressing the heat radiation that has entered the outer periphery of the vacuum heat insulating material 7, i.e., the body 1 side by heat conduction. can do. For example, when a compressed melamine foam having a thermal conductivity of 0.032 W / mK and t = 2 mm is wound around the outer periphery of the vacuum heat insulating material 7 on the body 1 side, the heat retaining performance is improved by about 4.5%.

  As described above, the heat insulation performance can be improved by winding the auxiliary heat insulating material around the outer periphery of the vacuum heat insulating material 7, that is, the body 1 side.

(Embodiment 5)
A fifth embodiment of the present invention will be described with reference to FIGS. When the auxiliary heat insulating material 8 in the figure is formed in the same cylindrical shape as the container 3, the heat insulating performance is improved and the assemblability is improved because the airtight convection does not occur because the auxiliary heat insulating material 8 is intimately adhered to the container. Of course, even if the auxiliary heat insulating material is not cylindrical, it has the same effect as long as it has the same shape as the container 3.

  When the auxiliary heat insulating material 8 in FIGS. 1 to 3 or 5 is physically or chemically fixed to the container 3, there is no gap between the vacuum heat insulating material 7 and the auxiliary heat insulating material 8, and there is no air convection. Thermal insulation performance is improved. Further, the auxiliary heat insulating material 8 may be fixed on the container 3 side. As means for fixing at this time, there are bonding by an adhesive, fixing by integral molding, fixing by welding, and the like.

  As described above, the electric water heater according to the present invention can reduce heat dissipation due to heat flowing around the outer periphery of the vacuum heat insulating material and can improve the heat insulating performance. It is useful as an application such as an electric water heater having a configuration for heat insulation.

Sectional drawing of the electric water heater in the 1st, 5th embodiment of this invention Sectional drawing of the electric water heater in 2nd, 5th embodiment of this invention Sectional drawing of the electric water heater in 2nd, 5th embodiment of this invention Sectional drawing of the electric water heater in the 3rd Embodiment of this invention Sectional drawing of the electric water heater in the 4th and 5th embodiment of this invention Sectional view of a conventional electric water heater

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Body 2 Liquid 3 Container 4 Upper frame 4a Upper frame lower part 5 Heating means 6 Lid body 7 Vacuum heat insulating material 7a Surface member 8 Auxiliary heat insulating material

Claims (9)

A body constituting the outer shell, an upper frame placed on the upper part of the body, a container for storing the liquid placed in the central opening of the upper frame, a lid covering the upper opening of the liquid, A heating means for heating the liquid in the container, a vacuum heat insulating material in which the inside of the surface member provided between the container and the body is evacuated, and an auxiliary heat insulation provided between the container and the vacuum heat insulating material And the auxiliary heat insulating material has a thermal conductivity smaller than that of the surface member of the vacuum heat insulating material. The electric water heater according to claim 1, wherein the auxiliary heat insulating material is sandwiched from the upper part of the outer periphery of the container to the lower end of the outer periphery of the container so that the container and the vacuum heat insulating material are not in direct contact with each other. The electric water heater according to claim 1, wherein the auxiliary heat insulating material is wound only on the lower side of the upper frame lower part of the outer periphery of the container, and the container and the vacuum heat insulating material are not in direct contact with each other at the upper peripheral part of the container. The electric water heater according to claim 1, wherein the auxiliary heat insulating material is wound only on the lower end portion of the outer periphery of the container, and the container and the vacuum heat insulating material are not in direct contact with each other at the lower peripheral portion of the container. The electric water heater according to claim 1, wherein the entire surface of the vacuum heat insulating material is covered with an auxiliary heat insulating material so that the container, the vacuum heat insulating material, the vacuum heat insulating material, and the atmosphere inside the body are not in direct contact with each other. A body constituting the outer shell, an upper frame placed on the upper part of the body, a container for storing the liquid placed in the central opening of the upper frame, a lid for covering the upper opening of the liquid, and the container A heating means for heating the liquid inside, a vacuum heat insulating material provided between the container and the body, and an auxiliary heat insulating material covering an outer peripheral portion of the vacuum heat insulating material, wherein the auxiliary heat insulating material is the vacuum heat insulating material. An electric water heater characterized by having a thermal conductivity smaller than that of. The electric water heater according to any one of claims 1 to 4, wherein the auxiliary heat insulating material is cylindrical. The electric water heater according to any one of claims 1 to 4 or 6, wherein the auxiliary heat insulating material is fixed to the vacuum heat insulating material. The electric water heater according to any one of claims 1 to 4 or 6, wherein the auxiliary heat insulating material is fixed to the container.

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