JPH043902B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a heat insulating material used in body warming devices and the like.

BACKGROUND ART Conventionally, flexible polyurethane foam has been mainly used in body warming devices.
However, in order to insulate the device with this heat insulating material, sufficient heat insulation cannot be obtained unless the thickness of the heat insulating material is increased. There was a problem that increasing the thickness would make the entire device bulky. In order to solve the above problem, the use of a vacuum heat insulating material is a conventional example considered prior to the present invention. Thermal conductivity of vacuum insulation materials can be improved by appropriately selecting space retaining materials.
The temperature can be reduced to 0.005 Kcal/mh°C or less, which is more than 6 times higher than the 0.03 Kcal/mh°C of flexible urethane foam. A conventional example will be explained according to FIG. The heat insulating material 1 is made of fine powder such as calcium silicate, glass or ceramic fiber, or a balloon, etc., to maintain an insulating gap in a vacuum state in a container 2 made of a film laminated with a plastic film and a metal foil. After inserting the heat insulating space retaining material 3 and drawing a vacuum, the container 2
Obtained by sealing.

Problems to be Solved by the Invention In the vacuum heat insulating material having the above structure, even if the heat insulating space holding material is flexible at normal pressure, it is compressed and solidified in a vacuum and loses its flexibility. . Therefore, when the vacuum heat insulating material is used in a body warming room, there is a problem that it is not flexible and feels strange, making it impractical.

The present invention aims to provide flexibility to a vacuum heat insulating material so that the user does not feel strange when heating.

Means for Solving the Problems In order to solve the above problems, the present invention cuts an insulating space retaining material into a plurality of small pieces, arranges the small pieces in the same plane, and then vacuum-seals the pieces. be.

Effect The present invention is attached to a heating device with the above configuration,
When worn on the body, the contact surface of each small piece of the heat insulating space retaining material becomes a line, and can be easily bent around this point in response to bending stress. That is, practical flexibility can be obtained.

Embodiments Hereinafter, embodiments of the present invention will be described based on the accompanying drawings. In Figure 1, 1 is a vacuum insulation material,
In a container 2 made of a film laminated with a plastic film and a metal foil or metal vapor deposited film,
It has a structure in which a heat-insulating space holding material 3 is vacuum-sealed. The heat insulating space retaining material 3 includes small pieces 31a, 31
It is composed of b...;32a... Reference numeral 4 indicates a line formed on the contact surface of the small piece of the heat-insulating space-keeping material, which is caused by applying a vacuum. Figure 2 is the X in Figure 1.
-X' cross section is shown.

In the above configuration, when an external force F is applied to the vacuum insulation material 1 as shown in FIG. Can be easily deformed. That is, it has the effect of having substantial flexibility against external forces.

There is a correlation between the gap l between the small pieces of the heat-insulating space retaining material and the flexibility, and when l=0, the resistance to bending stress is strong. As l increases,
Resistance to bending stress is reduced. In other words,
Flexibility increases. Heat insulating space retaining material 3
When the thickness of is d, the flexibility no longer increases when l>2d. This is because, as shown in FIG. 3, no resistance other than the resistance of the material of the container 2 is applied to the bending. Practically l>
Preferably it is 1/4d. If it is less than this, the resistance to bending stress is unfavorable.

On the other hand, in terms of heat insulation performance, it decreases as l increases. As shown in FIG. 3, when the temperature becomes ld, there is a high possibility that the top and bottom surfaces of the container will come into contact A. If they come into contact, heat conduction at the contact point A will increase, and the insulation performance will be greatly reduced. One way to prevent contact A is to increase the thickness of the laminate film, but this reduces flexibility and is not practical. Therefore, by setting the interval between the pieces of the heat insulating space retaining material in the range of 1/4d<l<d, a vacuum heat insulating material having high heat insulating performance and flexibility can be obtained.

The heat insulation performance also relates to the ratio of the area occupied by the heat insulating space retaining material 3 to the striated portion, that is, the portion where the heat insulating space retaining material 3 does not exist. Generally speaking, in ultra-high vacuum, the larger the area occupied by the streaks, the better the insulation performance, but for practical purposes 0.1
In a vacuum of ~1 mmHg, heat loss occurs due to convection. Therefore, when a material having a thermal conductivity of about 0.03 Kcal/mh°C is used for the heat insulating space retaining material 3, the area occupied by the heat insulating space retaining material is preferably 50% or more. When it is less than 50%, the effect of heat loss due to convection in the striations appears and the insulation performance deteriorates.

Next, as another embodiment of the present invention, a case where the heat insulating material of the present invention is used in a cordless heating device using a latent heat storage material will be described using FIG. 4. Figure 4a
, 5 is a body warming device, and 6 is an attachment for attaching to the body. FIG. 4b is a sectional view taken along the line YY' in FIG. 4a. In FIG. 4b, 7 is a heat storage mat, which has a structure in which a latent heat storage material is sealed in a flexible container, and the flexible containers are arranged in a grid. Latent heat storage material, for example, sodium thiosulfate pentahydrate (melting point 48℃, latent heat
48cal/g) Sodium acetate trihydrate (melting point 58℃,
Latent heat (60 cal/g), etc., can absorb or release a large amount of heat when the phase changes from solid to liquid at the melting point, and from liquid to solid. Therefore, when a latent heat storage material is used in a warming device, heat can be released over a long period of time after storing heat (in a molten state), so that the heating device can be cordless. 8 is a heating source, and generally an electric heater is used. The heating source 8 is used to store heat in the latent heat storage material. Therefore, if heat storage is performed using a device other than the heating device 5, it is not necessary. The heating device 5 includes the heat storage mat 7 and the heating source 8.
The outer periphery of the structure is covered with a heat insulating material. A feature of the present invention is that the flexible vacuum heat insulating material described in Example 1 is used as the heat insulating material. On the outside air side, it is preferable that the thickness of the heat insulating material be as thick as possible in order to prevent heat release, and therefore the thickness of the heat insulating space holding material 3 is increased. On the other hand, since the human body side requires heat release to an extent that does not cause low-temperature burns, the thickness of the heat insulating space retaining material 3' is thinner than that on the outside air side. Thermal conductivity of the vacuum insulation material is 0.015 Kcal/mh°C, which is made by arranging insulating space holding materials 3 made of 30 mm square glass paper with a thickness of 6 mm vertically and horizontally with a gap of 3 mm, and vacuum-sealing them at a vacuum degree of 1 mmHg.
It has approximately twice the heat insulation performance of polyurethane foam, which is commonly used.

Now, the vacuum insulation material 1 with a thickness of 6 mm is placed on the outside air side, and the vacuum insulation material 1 with a thickness of 3 mm obtained in the same manner (with a gap of 1.5 mm in the insulating space holding material 3') is placed on the human body side, and a heating device is installed. When fabricating this, heat dissipation properties were almost the same as those using conventional polyurethane foam. In addition, since the vacuum insulation material 1 has the above-mentioned lines, it is flexible and does not feel strange even when worn and carried out. As a result, the thickness of the conventional heat insulating material, which was 12 mm on the outside air side and 6 mm on the human body side, totaling 18 mm, was halved to 9 mm, allowing the heating device 1 to be made thinner. In addition, in order to keep the overall thickness of the insulation layer the same as before, if the heating device 5 is made using vacuum insulation material 1 with a thickness of 15 mm on the outside air side and 3 mm on the human body side, the heat dissipation time will be reduced from the conventional 4 hours to 7 hours. I was able to do that. That is, in the case of a heating device of the same size, the pot life can be approximately doubled.

In addition, in this example, as the heat-insulating space retaining material,
Although the description has been made using a quadrilateral, the shape is not limited to a quadrilateral, and may be a circle or other shape.

Effects of the Invention As described above, the heat insulating material of the present invention provides the following effects. That is, since the heat-insulating space-maintaining material of the heat-insulating material of the present invention is composed of a plurality of small pieces of heat-insulating space-maintaining material, even if bending stress is applied, it can be easily bent around the lines between the small pieces. be able to. That is, it can be made into a flexible vacuum heat insulating material. Therefore, when used as a heat insulating material for a body warming device, the material does not feel strange due to its flexibility. Furthermore, since the heat insulating performance is high, when the same heat insulating performance as the conventional one is required, the thickness of the heat insulating material can be made thinner, and the device can be made smaller. Furthermore, when using heat insulating materials with the same thickness, the heat retention effect can be enhanced.

[Brief explanation of drawings]

Figure 1 is a partially cutaway perspective view of a vacuum heat insulating material according to an embodiment of the present invention, Figures 2 a and b, and Figure 3 are X in Figure 1.
-X' line sectional view, Fig. 4a is a perspective view of a heating device made using the same vacuum insulation material, Fig. 4b is a Y-Y' line sectional view of Fig. 4a, and Fig. 5 is a conventional FIG. 3 is a partially cutaway perspective view of the vacuum insulation material of FIG. 1...Vacuum insulation material, 2...Container, 3...Insulating space holding material.

Claims (1)

[Scope of Claims] 1. A vacuum heat insulating material comprising a plurality of heat insulating space holding members arranged on the same plane and a flexible container containing the heat insulating space holding members. 2. Claim 1 states that the heat-insulating space-maintaining materials are arranged so that 1/4d<l<d, where d is the thickness of the heat-insulating space-maintaining material and l is the gap between the heat-insulating space-maintaining materials. vacuum insulation.