JP2549719B2 - Box insulation - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat insulating structure for a low temperature heat insulating box such as a refrigerator, a freezer, and a dry ice storage, and a high temperature insulating box for an electric furnace.

2. Description of the Related Art As a conventional box body using a vacuum heat insulator, as shown in FIG. 6, a box in which a double-structured metal cover material 2 is filled with powder or fiber 1 having heat insulation and pressure resistance is used. There is one formed in a shape. The box body using this vacuum heat insulator 3 has a structure in which the vacuum heat insulator 3 itself maintains its strength.
A metal member (hereinafter referred to as a membrane portion) 5 that crosses the heat insulating layer of the powder or the fiber 1 is required, and in order to suppress heat invasion or heat dissipation through the membrane portion 5, the membrane portion 5 has a comparison of thermal conductivity. Austenitic stainless steel, which is very small, was used, and a plate material that was as thin as possible was used. In FIG. 6, 6 is a lid, 7 is a packing, and 8 is a packing contact plate.

Further, as another box body using the vacuum heat insulating material, there is one in which a vacuum heat insulating material using a metal foil laminate film is combined with polyurethane foam. In the case of this box, a structure that maintains the shape of the product is provided by a separately provided exterior structural material and foamed polyurethane.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, in a box having the membrane portion 5, even if the thin membrane portion 5 is used, the membrane portion 5
When the inside of the box body is low in temperature, the temperature of the outer surface side portion of the vacuum heat insulator 3 is locally low, so that dew condensation or the like may occur, and when the inside of the box body 4 is high in temperature, the temperature is locally low. The temperature is extremely high, so there is a risk of accidental touching of this part and burns. Further, although the membrane portion 5 is welded and attached to the metal cover material 2, there is a problem that the membrane portion 5 is very thin and thus a leak or the like is likely to occur.

In addition, while the box body in which the vacuum heat insulator is combined with the foamed polyurethane is less likely to cause local temperature unevenness, an exterior structure for maintaining the product shape is required separately from the vacuum heat insulator, and only that much. It was a cost increase.

The present invention solves the above problems, and does not cause dew condensation, may cause burns, does not cause a leak, and does not require a structure for holding the product shape. It is intended to provide a heat insulating structure for the body.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention fills a powder or fiber into a metal cover material having a double structure to form a box-shaped vacuum heat insulator, and heat insulation in this vacuum heat insulator. At least one of the inner surface side and the outer surface side of the vacuum heat insulating body in the membrane portion arranged in the direction crossing the layers is covered with a normal pressure heat insulating material.

Action With the above configuration, since at least one of the inside and the outside of the portion of the box body where the membrane portion is provided is covered with the atmospheric pressure heat insulating material, the heat that enters the membrane portion is reduced or the heat is dissipated from the membrane portion. The heat that is transferred becomes difficult to transfer, and the outer surface side portion of the box body corresponding to the outer surface side portion of the box body in the membrane portion or the vacuum heat insulating body outer surface side portion in the membrane portion locally becomes hot. It will never become cold. As a result, there is no risk of dew condensation or the risk of burns.Because the membrane part can be thicker than conventional ones, the welding work of the membrane part can be facilitated and no leakage will occur. . Moreover, since the atmospheric pressure heat insulating material is held by the vacuum heat insulating body, it is not necessary to provide a separate structure for holding the atmospheric pressure heat insulating material.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a simplified heat insulation diagram showing a heat insulation structure of a box according to an embodiment of the present invention. In FIG. 1, 11 is a box-shaped vacuum heat insulator having an opening at the top, which is a metal cover material 13 having a double structure of powder or fiber 12 having excellent heat insulation and heat resistance.
And the inside of the metal cover material 13 is sealed by vacuum. 14 is this vacuum insulator 11
Is a metal membrane part which is arranged on the upper surface part of the above in a direction crossing a heat insulating layer formed of powder or fibers 12. The outer surface side of the vacuum heat insulating body 11, including the outer surface side portion of the membrane portion 14, is covered with the atmospheric pressure heat insulating material 15. A packing pad 16 made of a heat insulating material is disposed on the membrane portion 14 of the vacuum heat insulating body 11, and outer surfaces of the packing pad 16 and the normal pressure heat insulating material 15 are covered with an exterior material 17. Reference numeral 18 denotes a lid having a packing 19 attached to the lower surface thereof, and the packing 19 is brought into close contact with the packing contact plate 16 to seal the inside of the vacuum heat insulator 11. Reference numeral 20 denotes a leg portion attached to the bottom surface of the vacuum heat insulating body 11 via a mounting metal fitting 21. As the atmospheric pressure insulating material 15, foamed polyurethane, expanded polystyrene, etc. are suitable for a box body for low temperature applications, and glass wool, ceramic wool, calcium silicate, etc. are suitable for a box body for high temperature applications. There is. Further, the vacuum heat insulating body 11 has a strength enough to hold the box body, and the exterior material 17 covering the atmospheric pressure heat insulating material 15 is mechanically coupled to the outer surface of the vacuum heat insulating body 11 or the vacuum heat insulating body 11 is used.
The normal pressure heat insulating material 15 is adhered to the outer surface of the, and the outer covering material 17 is further adhered to the outside of the normal pressure heat insulating material 15 and the outer covering material.
17 is supported by the vacuum heat insulator 11.

With the above configuration, the vacuum heat insulator in the membrane unit 14
The temperature of the portion 14a on the outer surface side of 11 locally becomes low or high, and temperature unevenness occurs.
Since it is covered by 15, the heat from this portion 14a is blocked by the atmospheric pressure heat insulating material 15 and is difficult to be transmitted to the outer surface side of the box body, and the portion 17a of the corresponding exterior material 17 becomes locally low temperature. It does not heat up or get hot. Therefore,
The outer surface side portion of the vacuum heat insulator 11 in the membrane portion 14
Condensation may occur on the part 17a of the exterior material 17 corresponding to 14a,
There is no risk of burns, and the membrane part 14 is thicker than the conventional one.
Since this makes it possible to use, it facilitates welding and prevents leakage and the like. Further, since the shape of the box is maintained by the vacuum heat insulating body 11, the exterior material of the atmospheric pressure heat insulating material 15 is used.
It is not necessary to adopt a structure capable of retaining the shape of 17, and the manufacturing cost can be reduced accordingly.

Next, the heat insulating structure of the box body according to another embodiment of the present invention will be described with reference to FIG. As shown in FIG. 2, in this embodiment, the entire inner surface side of the vacuum heat insulating body 31 formed by filling the metal cover material 33 with the powder or fiber 32 is covered with the normal pressure heat insulating material 35, An interior material 37 is further arranged on the inner surface of the heat insulating material 35. The attachment structure of the vacuum heat insulating body 31, the normal pressure heat insulating material 35, and the interior material 37 is configured in the same manner as in the above embodiment, and the vacuum heat insulating body 31 allows the normal pressure heat insulating material 35 and the interior material 37.
Is supported.

In the above-mentioned configuration, since the atmospheric pressure heat insulating material 35 is arranged inside the vacuum heat insulating body 31, heat is generated by the atmospheric pressure heat insulating material 35 even though the inside of the box is at low temperature or high temperature.
Therefore, the temperature of the inner surface portion 34a of the vacuum heat insulating body 31 in the membrane portion 34 does not become too low or high, and the vacuum heat insulating body in the membrane portion 34 is naturally not heated. Outer part of 31
The temperature of 34b also does not locally become low or high, and there is no possibility of dew condensation or the risk of burns at this portion 34b. Further, in this case, the temperature of the portion 34a on the inner surface side of the vacuum heat insulating body 31 in the membrane portion 34 is changed to the vacuum heat insulating body
1 Since it does not become as cold or hot as the inside,
There is also an effect that the thermal stress generated in 4a is also reduced, and the life of repeated use is extended. Also, similar to the above embodiment,
Manufacturing costs can be reduced.

FIG. 3 shows a heat insulating structure for a box body according to a third embodiment of the present invention. In this embodiment, a metal cover material is used.
An inner surface side and an outer surface side of a vacuum heat insulating body 41 formed by filling powder or fibers 42 into 43 are covered with atmospheric pressure heat insulating materials 45A and 45B, respectively, including a portion in contact with the membrane portion 44. Further, 47A and 47B are interior materials and exterior materials, and these atmospheric pressure insulation materials 45A and 45B and interior materials 47A and exterior materials 47B are attached to the vacuum heat insulating body 41 in the same manner as in the above-mentioned embodiment and their shapes are maintained. ing.

With this configuration as well, the same operational effects as those of the above-described embodiment can be obtained, and particularly, according to this embodiment, since the atmospheric pressure heat insulating materials 45A and 45B are provided on both surface sides of the vacuum heat insulating body 41, the membrane portion 44 is provided. The temperature unevenness of the portion 47a of the exterior material 47B corresponding to the portion 44a on the outer surface side of the vacuum heat insulating body 41 is further reduced.

Furthermore, FIG. 4 is a simplified cross-sectional view showing the heat insulating structure of the box body of the fourth embodiment of the present invention. As shown in FIG. 4, in this embodiment, the outer surface side of the vacuum heat insulating body 51 in the membrane portion 54 is Only the portion 54a of is covered with the atmospheric pressure heat insulating material 55.
With this configuration as well, the same effects as those of the above-described embodiment can be obtained, and further, since the atmospheric pressure heat insulating material 55 is provided only on the outer surface side portion of the membrane portion 54, the manufacturing cost can be further reduced. Contrary to the case shown in FIG. 4, it is also possible to cover only the portion of the membrane portion 54 on the inner surface side of the vacuum heat insulating body 51 with the atmospheric pressure heat insulating material 55. In this case, as shown in FIG. Similarly, there is an effect that the thermal stress generated in the inner surface side portion becomes small, and the life of repeated use is extended. In FIG. 4, 52 is powder or fiber,
53 is a metal cover material.

Next, the portion including the membrane portion of the low temperature box is modeled as shown in FIGS. 5 (a), (b), and (c), and the heat insulating structures of the conventional and present boxes are two-dimensionally stationary. The results of thermal conductivity analysis are shown in Table 1. Here, in FIG.
(A) is a model of the conventional heat insulation structure of the box (referred to as structure A), (b) is a model of the heat insulation structure of the box of the first embodiment (referred to as structure B), (C) is a sectional view showing a model (referred to as a structure C) of the heat insulating structure of the third embodiment. In addition, FIG. 5 (a), (b),
In each of (c), the upper side is the inside of the box, the lower side is the outside of the box, the temperature inside the box is 0 ° C, the temperature outside the box is 30 ° C, and the surface heat transfer coefficient on each side is 11.6. W / m ² K
Is set to The length of the box body is 500 mm, the thickness of the box body is 100 mm, and the thickness of the vacuum heat insulator 11 of structure B is 90 m.
m, the thickness of the vacuum insulator 41 of structure C is 80 m, the metal cover material
Thermal conductivity of 2,13,43 and membrane parts 5,14,44 is 16.3W /
mK, thermal conductivity of the heat insulating material 8,16,46 corresponding to the packing pad in the above embodiment is 0.058 W / mK, normal pressure heat insulating material 15,45
A, 45B has a thermal conductivity of 0.02 W / mK, the thermal conductivity of the heat insulating layer of the vacuum heat insulating body 11, 41 filled with powder or fibers 1, 12, 42 is 0.0
It is 05W / mK. In this condition, the membrane part 5,14,44
The thickness t of is divided into 1 mm and 0.3 mm, as shown in FIG.
The temperature and the amount of heat passing through at the positions T _{1 to} T ₄ shown in (b) and (c) were examined.

As shown in Table 1, in the structures B and C, the temperature T ₄ of the portion of the exterior material 17,47B corresponding to the portion where the membrane portions 14,44 and the outer surface of the metal cover material 13,53 are in contact is the box. It can be seen that the temperature is close to the temperature outside the body, the local temperature unevenness is reduced, and the amount of heat passing through is reduced.

EFFECTS OF THE INVENTION As described above, according to the present invention, since at least one of the inner surface side and the outer surface side of the vacuum insulator in the membrane portion is covered with the atmospheric pressure heat insulating material, the membrane portion vicinity portion on the outer surface side of the box body Since the local temperature unevenness of the is reduced, the risk of dew condensation and burns that have occurred in the past can be prevented, and since the membrane part can be thicker than the conventional one,
There is no leak. Further, since the structure for holding the atmospheric pressure heat insulating material can also be used as the vacuum heat insulating material, the manufacturing cost can be reduced.

[Brief description of drawings]

FIG. 1 is a simplified sectional view showing a heat insulating structure of a box body of a first embodiment of the present invention, FIG. 2 is a simplified sectional view showing a heat insulating structure of a box body of the same second embodiment, and FIG. 3 is a simplified sectional view showing the heat insulating structure of the box body of the third embodiment, FIG. 4 is a simplified sectional view showing the heat insulating structure of the box body of the fourth embodiment, and FIGS. 5 (a), (b) and (c).
FIGS. 6A and 6B are cross-sectional views of a conventional model and a model for comparing the heat insulating structures of the boxes, respectively, and FIG. 6 is a simplified cross-sectional view showing the heat insulating structure of the conventional box. 11,31,41,51 …… Vacuum insulation, 12,32,42,52 …… Powder or fiber, 13,33,43,53 …… Metal cover material, 14,34,44,54…
… Membrane materials, 15,35,45,55 …… Atmospheric pressure insulation materials.

Claims (1)

(57) [Claims] 1. A box-shaped vacuum heat insulator is formed of a double-structured metal cover material, and an inner surface of an upper vacuum heat insulator in a membrane portion arranged in a direction crossing a heat insulating layer of the vacuum heat insulator. Insulation structure of a box body in which at least one of the side or the outer surface side is covered with a normal pressure heat insulating material.