JPH07113494A - Vacuum insulating member - Google Patents

Abstract

PURPOSE:To provide a vacuum insulating member which can reduce a clearance part formed at the end part side position of an armor body for accommodating a core material. CONSTITUTION:As for a vacuum insulating member 1 which is constituted so that the inside of an armor body 3 which has an airtight chamber inside is charged with the heat insulating core material 2, and the airtight chamber is vacuum-exhausted, the armor body 3 has each opened port part 3 at both the end parts in the axial direction and is constitution of a cylindrical member of a heat shrinkage type film which is shrinked in the peripheral direction by heating, and a pair of clearance parts 6 are formed at both the end parts through sealing, in the state where the heat insulating core material 2 is accommodated in the cylindrical member, and vacuum exhaust is carried out.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum heat insulating material which is attached to a cryogenic container, a refrigerator, a cooler for leisure, or a conduit for transferring a cryogenic fluid or other plant equipment to exert a heat insulating effect.

[0002]

2. Description of the Related Art The structure of a conventional vacuum heat insulating material is shown in FIGS. FIG. 5 shows a vertical sectional view of the vacuum heat insulating material, and FIG. 6 shows a plan view thereof. As shown in both figures, the vacuum heat insulating material is a molded product in which powder such as silica or perlite is put into a permeable bag such as a kraft paper bag or a non-woven fabric and then formed into a fixed shape, or an open cell phenol foam. A molded body or the like is provided as the heat-insulating core material 2, and the heat-insulating core material 2 is, for example, a plastic laminate film exterior body 3 composed of a pair of upper and lower sheet members.
(The storage portion serves as the airtight chamber 4) and the air inside the exterior body is evacuated, and then the opening portion of the exterior body (this portion mainly serves as a surplus portion 6 described later) is fusion-sealed. It was stopped and configured. Therefore, in the vacuum heat insulating material of this configuration, as shown in FIG.
As shown in FIG. 6, a relatively long extra length portion 6 is provided on the four edge portions of the exterior body.

[0003]

This extra length is a problem. When the vacuum insulating material is manufactured, when the heat insulating core material is housed in the outer package, the outer package is considerably larger than the heat insulating core material. Otherwise, it is difficult to accommodate the heat-insulating core material, and if there is no space between the heat-insulating core material and the exterior body during vacuum exhaust, the exhaust resistance is large and it is difficult to evacuate the interior of the exterior material. It is necessary to make the outer casing considerably larger than the heat insulating core material, and at present, the vacuum heat insulating material produced has a relatively large extra length portion in the periphery. Since this extra length portion generally does not have heat insulation performance, when a vacuum insulating material is used to create a heat insulating wall, a joint is generated between the heat insulating materials, and the treatment of this extra length portion becomes a problem. It was Further, there is a problem that the flow of the urethane foam is deteriorated when a peripheral wall of a plurality of vacuum heat insulating materials is filled with urethane foam to form a heat insulating wall. Therefore, as shown in FIG. 7, as a means for solving this,
It is conceivable that the extra length is bent to the body side and fixed to the heat insulating main body, but in general there are extra lengths on the four sides, so 2
There is a problem that a bending process is required twice, which is troublesome, a pinhole is apt to be generated at a crossing portion of the bending, and a surplus length portion is slightly left after the bending.

Therefore, an object of the present invention is to provide a vacuum heat insulating material which can make the extra length portion formed at the end side portion of the outer casing accommodating the core material as small as possible.

[0005]

To achieve this object, the vacuum heat insulating material according to the present invention is characterized in that a heat insulating core material is filled in an exterior body forming an airtight chamber, and the airtight chamber is vacuumed. The evacuated vacuum heat insulating material is provided with a heat-shrinkable portion that shrinks by heating, and its action and effect are as follows.

[0006]

In the exterior body having such a structure, when the heat insulating core material is housed inside the exterior body, the interior is evacuated, the opening of the exterior body is fusion-sealed, and then the exterior body is heated. , The heat-shrinkable part shrinks. Therefore, for example, when the exterior body is formed in a tubular shape, the exterior body can be closely attached to the heat insulating core material in the circumferential direction of the tubular member, and should be configured as an extra length portion. The parts are limited to both ends of the tubular member. On the other hand, for example, when a vacuum heat insulating material as shown in FIG. 6 is formed by using an exterior body composed of a pair of upper and lower sheet-like members as in the related art, heat shrinkage is caused at a portion to be an extra length. With the provision of, the extra length can be made narrower than the conventional width.

[0007]

That is, by using the outer package having the heat-shrinkable portion, a vacuum heat insulating material having a small extra length portion formed at the end side portion of the outer package accommodating the heat insulating core material is obtained. I was able to. Further, here, as the exterior body, a tubular member having openings at both ends in the axial direction and formed of a heat-shrinkable film that causes heat shrinkage in at least the circumferential direction is adopted, and a heat insulating core material is used. If a member that forms an extra length portion at both ends by sealing in a state of being housed inside a tubular member and evacuated, the extra length portion is generated only on two opposing sides, and It is possible to create a vacuum heat insulating material having a short portion, and by using this as a heat insulating wall, it is possible to obtain a heat insulating structure having almost no joints. Also,
Even when creating a heat insulating wall by combining a vacuum heat insulating material and urethane foam, it does not block the flow of urethane,
It is possible to create an insulation machine with few defective parts such as voight.
Further, in this case, even when the extra length portion is bent, the conventional vacuum heat insulating material has extra length portions on the four surrounding sides, so it is necessary to perform the bending process twice with the corresponding sides as a pair. There was a problem that pinholes were likely to occur at the intersection of bending, but in this case there is only an extra length on the two opposite sides, so it is sufficient to perform the bending process once, and such problems do not occur easily. .

[0008]

Embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a vertical sectional view of the vacuum heat insulating material 1, and FIG. 2 shows a plan view of the vacuum heat insulating material 1. Furthermore, in FIG.
Insulating core material 2 and exterior material 3 before vacuum evacuation operation
The shape relationship of is shown. As shown in FIG. 1, the vacuum heat insulating material 1 of the present application is configured by filling a heat insulating core material 2 in an exterior body 3 which forms an airtight chamber 4 therein, and evacuating the airtight chamber 4. Here, in the illustrated example, the heat insulating core material 2 is formed as a rectangular parallelepiped having a flat vertical cross section. Now, the configuration of the exterior body 3 and the manufacturing process of the vacuum heat insulating material 1 will be described below. First, the exterior body 3 is shown in FIG.
As also shown in FIG. 3, the openings 3a are provided at both ends in the axial direction,
Further, it is composed of a tubular member 5 made of a heat-shrinkable film which shrinks at least in the circumferential direction by heating. When manufacturing the vacuum heat insulating material 1, with respect to the heat insulating core material 2 having a rectangular parallelepiped shape, the opening portions 3a at both ends of the tubular member 5 are arranged along a pair of end surfaces 2a of the heat insulating core material 2 which face each other. Perform molding while arranging. That is, with the above arrangement, the heat insulating core material 2 is housed in the tubular member 5, and the tubular member 5 is placed in a vacuum chamber (not shown) in which heating can be performed.
After the inside is evacuated, the pair of openings 3a located at both ends of the tubular member 5 are fusion-sealed to form this portion as the extra length portion 6. After that, as a result of heating from the periphery of the exterior body 3, the exterior body 3 is configured to be heat-contracted at least in the circumferential direction of the tubular member. Therefore, the exterior body 3 is contracted in this direction, and the exterior body 3 and the heat insulating core material are contracted. There is no gap between the two and the cross section has a structure as shown in FIG. After that, when the inside of the vacuum chamber (not shown) is returned to normal pressure, the extra length 6 only needs to be in two directions as shown in FIG. A short vacuum insulation 1 is obtained.

As the heat-insulating core material 2, there are used a molded product obtained by forming powder of silica, pearlite or the like into a certain shape, a calcium silicate molded product, an open-cell urethane foam, a phenol foam or the like. The heat-shrinkable film is a film which is stretched in the longitudinal direction or in the two directions of length and width to form a film and cooled when a thermoplastic film such as polyethylene, polypropylene or polyvinyl chloride is produced, and is stretched only in the longitudinal direction. A biaxially stretched heat-shrinkable film is a film that is uniaxially stretched in both longitudinal and transverse directions. When heated, the uniaxially stretched film shrinks only in the machine direction, and the biaxially stretched film contracts in both the machine and transverse directions. When a tubular heat-shrinkable film is used for the rectangular parallelepiped heat insulating core material 2 as described above, the circumferential direction of the tubular member or the circumferential direction and the axial center direction shrink. FIG. 2 shows an example in which a uniaxially stretched film is used, and both open ends 3a of the tube are shown.
A pair of extra length portions 6 are formed on the sides. In this case, it can be said that the effect of using the heat-shrinkable film is that the extra length portion 6 is limited to two sides. Further, FIG. 4 shows a vacuum heat insulating material 1 using a biaxially stretched film as the exterior material 3. In this case, the extra length portion 6 itself also contracts, and the extra length portion 6 formed on the pair of opposing side portions can be smaller than in the conventional case.

Further, as the exterior body 3 of the vacuum heat insulating material 1, it is necessary to keep the interior of the exterior body under vacuum for a long period of time, and it is necessary to have a gas barrier function so as to prevent gas from entering the interior of the exterior body from the outside. is there. Therefore, in a uniaxially stretched film, it is desirable to laminate an aluminum foil or an aluminum vapor deposition film (not shown) as a gas barrier layer. At this time, the aluminum foil or the aluminum vapor-deposited film may be preliminarily provided with folds so as not to hinder the shrinkage of the uniaxially stretched film as much as possible. On the other hand, a biaxially stretched film can also be configured in the same manner, but as another method, a method in which the above vacuum heat insulating material is prepared only by a stretched film, and then an aluminum vapor deposition layer is provided on the surface of the exterior body, or an aluminum foil It is also possible to add gas barrier performance by post-processing such as attaching.

[Other Embodiment] Another embodiment of the present application will be described below. (A) In the above embodiments, the heat insulating core material 2 has an example of a rectangular parallelepiped shape, but these shapes are arbitrary, and the exterior body 3 also has a pair of upper and lower sheets. It can be arbitrarily constructed, such as a die-shaped film. (B) In the above embodiments, the entire outer package is made of a material having heat shrinkability, but for example, only a pair of upper and lower specific parts of the outer package may be provided with heat shrinkability.
In this case as well, the contraction of the specific portion causes the surrounding portions to be attracted, so that, for example, in the example of the tubular member described above, the extra length portion can be limited to a pair of opposing end faces. Becomes Further, only the portion expected as the extra length portion may be provided with heat shrinkability.

It should be noted that although reference numerals are given in the claims for convenience of comparison with the drawings, the present invention is not limited to the configurations of the accompanying drawings by the entry.

[Brief description of drawings]

FIG. 1 is a diagram showing a vertical sectional structure of a vacuum heat insulating material.

FIG. 2 is a plan view of a vacuum heat insulating material that uses an exterior material that causes uniaxial thermal contraction.

FIG. 3 is a diagram showing a relationship between a core material and an exterior material before performing heating and vacuum evacuation operations.

FIG. 4 is a plan view of a vacuum heat insulating material that uses an exterior material that causes thermal contraction in two axial directions.

FIG. 5 is a view showing a vertical sectional structure of a conventional vacuum heat insulating material.

FIG. 6 is a plan view of a conventional vacuum heat insulating material.

FIG. 7 is a view showing a vertical cross-sectional structure of a vacuum heat insulating material in which an extra length portion is folded back to the main body side.

[Explanation of symbols]

 1 vacuum heat insulating material 2 heat insulating core material 3 exterior body 3a opening 4 airtight chamber 6 extra length

Claims (3)

[Claims] 1. A vacuum heat insulating material in which an exterior core (2) which forms an airtight chamber (4) inside is filled with a heat insulating core material (2) and the airtight chamber (4) is evacuated ( 1) and
A vacuum heat insulating material comprising a heat-shrinkable portion that shrinks when heated by the outer casing (3). 2. The exterior body (3) is a tubular member formed of a heat-shrinkable film having openings (3a) at both ends in the axial direction, and the heat insulating core material (2) is The vacuum heat insulating material according to claim 1, wherein a pair of extra length portions (6) are formed at the both end portions by sealing in a state of being housed inside the tubular member and being evacuated. 3. The heat insulating core material (2) has a rectangular parallelepiped shape, and the tubular member contracts at least in a direction orthogonal to its axis by heating, and the openings at both ends of the tubular member are formed. The heat insulating core material (2) is molded along a pair of end surfaces of the heat insulating core material (2) facing each other.
The vacuum insulation material described.