JPH04127498U - Structure of vacuum insulated box - Google Patents

Abstract

(57) [Summary] [Purpose] To prevent damage to the membrane due to thermal expansion of the inner box of a vacuum insulated box. [Structure] A membrane 5 sealing a vacuum heat insulating layer 4 connects the opening side peripheries of an inner box 1 and an outer box 2. Supports 7,
8 are provided protrudingly shifted in the depth direction of the box so that both the inner and outer boxes 1 and 2 are not thermally short-circuited. A solid heat insulating material 9 is sandwiched between the supports 7 and 8. The insulation thickness T of the vacuum insulation layer 4 in a portion corresponding to the rear wall of the box body is formed to be thicker than the insulation thickness t in other portions. [Effect] When the inner box 1 thermally expands, the support 7 pushes the solid heat insulating material 9, but this is received by the support 8 and the expansion toward the membrane is prevented, and the deformation of the membrane 5 is restricted and its Damage is prevented.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

The present invention relates to the structure of a vacuum insulated box, which is particularly suitable for storing high-temperature items. Concerning the structure of a vacuum insulated box.

0002

[Conventional technology]

A conventional vacuum insulated box body consists of an inner box 1 and an outer box 2, as shown in FIG. 4, for example. A box with a double wall structure having an opening 3 on one side is formed, and there is a wall between the inner box 1 and the outer box 2. A hollow heat insulating layer 4 is formed. In addition, due to the membrane 5 that seals the vacuum insulation layer 4, , connects the opening side peripheries of the inner box 1 and the outer box 2. There is a lid (not shown) in opening 3. By covering it, a vacuum insulated container is constructed. The vacuum insulation layer 4 has insulation for each part. The powder heat insulating material 6 is filled so that the thickness t is equal. Membrane 5 is a thin plate It is designed to maintain its insulation properties by reducing heat dissipation through thermal conduction.

0003

[Problem that the idea aims to solve]

However, when the conventional vacuum insulated box mentioned above stores high-temperature items, as shown in Fig. 5, In other words, the temperature of the inner box 1 rises and expands by Δl. Thickness of the rear wall opposite to opening 3 If Δl is sufficiently small compared to t, inner box 1 has Δl on the membrane and the opposite side. Expand by l/2. Therefore, a large stress is generated in the membrane 5 made of thin plate, If this is repeated, the membrane 5 will be damaged and the vacuum insulation layer 4 will be destroyed. There is a problem. However, in order to reduce the deformation Δl/2 on the membrane side, In addition, if a thick and rigid material is used for the membrane 5, the A problem arises in that heat dissipation increases and insulation performance deteriorates.

0004 Therefore, this invention solves these problems and prevents the deterioration of insulation performance. The purpose is to prevent membrane damage.

[0005]

[Means to solve the problem] In order to achieve the above object, the present invention provides an inner surface of the inner box and outer box near the membrane. In this case, the first and second supports are shifted in the depth direction of the box, and These first and second supports are provided so as to protrude from each other to prevent the box from being thermally short-circuited. A solid insulating material is interposed between the The insulation thickness of some parts is thicker than that of other parts.

[0006]

[Effect]

When high-temperature items are stored in the vacuum insulated box with the above configuration, the inner box will rise in temperature and expand. The first support pushes the solid insulation, which is then pushed by the second support. I can accept it. This prevents the inner box from expanding near the membrane. Therefore, the inner box expands only on the side opposite the membrane, and the membrane deforms. do not have. Therefore, even if the inner box is repeatedly heated and cooled, the membrane will be damaged and the There is no possibility of vacuum breakdown in the empty insulation layer. In addition, the box body in the vacuum insulation layer The insulation thickness of the part corresponding to the rear wall is thicker than that of other parts. , which absorbs the expansion of the inner box and connects the first support and the second support to thin plates. It becomes possible to produce. Furthermore, when the inner box expands and contracts, The vacuum insulation layer responds by elastic compression and expansion.

[0007]

【Example】

An embodiment of the present invention is shown in FIGS. 1 and 2. The vacuum insulation layer 4 has a insulation thickness T at a portion corresponding to the rear wall of the box body, which is greater than the insulation thickness at other portions. It is configured to be thicker than the thickness t. This insulation thickness T is at least Due to the elastic compression and expansion of the powder heat insulating material 6 in this part, the inner box 1 expands and expands, which will be described later. Make settings so that it can respond to expansion and contraction.

[0008] On the inner surfaces of the inner box 1 and the outer box 2 in the vicinity of the membrane 5, a first support 7 and a A second support 8 is provided in a protruding manner. These supports 7, 8 are the first supports. The inner box 1 and the outer box 2 are arranged so that the holder 7 is located further back than the second support 8. are constructed to prevent thermal short-circuiting. The first support 7 and the second support 8 A solid heat insulating material 9 is provided between them. The solid insulation material 9 has thermal insulation and compression properties. It is necessary to have strength, such as a calcium silicate molded body with continuous pores. It is preferable to use

[0009] High-temperature items are stored inside the vacuum insulated box with such a configuration, and the opening 3 is connected to the lid ( (not shown), the inner box 1 increases in temperature and expands by Δl, as shown in Figure 2. do. However, the solid heat insulating material 9 is sandwiched between the first support 7 and the second support 8. , this prevents the inner box 1 from expanding toward the membrane 5, so the inner box 1 It expands only on the side opposite to the membrane 5. Therefore, membrane 5 is not deformed. Even if the inner box 1 is heated and cooled repeatedly, the membrane 5 is damaged and the vacuum insulation layer 4 is damaged. There is no possibility of vacuum destruction.

0010 In addition, the insulation thickness T of the vacuum insulation layer 4 in the part corresponding to the rear wall of the box is different from that in other parts. Since it is thicker than the thermal thickness t, the expansion of the inner box 1 is absorbed and this The first support 7 and the second support 8 that receive the expansion force can be made of thin plates. Wear. Then, the inner box 1 expands due to at least the elastic compression and expansion of the powder insulation material 6. , by setting the insulation thickness T to accommodate shrinkage, the powder insulation material This prevents the inner box 1 from expanding significantly beyond the elastic range of 6.

A specific example will be explained. The conventional inner box 1 shown in Fig. 5 and the inner box 1 of ^the present invention shown in Figs. , their depth l was 1,500 mm, their insulation thickness t was 60 mm, and their insulation thickness T was 120 mm. In such a product, when the outside temperature θ ₀ is 20°C and the internal temperature θ of both inner boxes 1, 1 is set to 350°C, the conventional inner box 1 will elongate Δl = α・l・(θ− θ ₀ ) = 16.4 × 10 ^-6 × 1500 × (350 −20) = 8 mm. That is, the vacuum heat insulating layer 4 and the membrane 5 are deformed by Δl/2=4 mm. This has been confirmed by the inventor through finite element analysis and experiments. The compressive deformation rate k of the vacuum heat insulating layer 4 at this time is k=Δl/2·t=4/60=0.067.

On the other hand, in the inner box 1 of the present invention, the elongation Δl=α·l·(θ−θ ₀ )=16.4×10 ⁻⁶ ×1500×(350 −20)=8 mm. However, since the membrane 5 is not deformed, the vacuum insulation layer 4 on the rear wall is compressively deformed by ΔL=8 mm. The compressive deformation rate k of the vacuum heat insulating layer 4 at this time is k=Δl/T=8/120=0.067, which is the same as the compressive deformation rate of the conventional inner box 1. This means that the forces acting on the rear wall are the same. In other words, it is possible to bring the deformation only toward the rear wall by adding the frictional force between the powder insulation material 6 and the inner box 1 to the rigidity of the membrane 5. . Therefore, in this case, the supporting metal fittings 7 and 8 do not need to have any strength, and can be constructed from thin plates having a thickness of 1 mm or less. When setting the insulation thickness T of the rear wall to 120 mm or less, it is necessary to design both supports 7 and 8 and select the solid insulation material 9 accordingly.

[0013] In addition, in the above embodiment, the solid heat insulating material 9 is formed between the first support 7 and the second support 8. Although the configuration is such that the first support is clamped, as another example, as shown in FIG. When solid heat insulating material 9 is placed between 7 and second support 8, A gap d may also be created. In this way, the inner box 1 will be opened by the gap d. The expansion force of the inner box 1 acting on the supports 7 and 8 is expanded toward the inner box 5 side. decreases by the amount. Therefore, thinner plates should be used for both supports 7 and 8. becomes possible.

[0014]

[Effect of the idea]

As described above, according to the present invention, the inner box expands due to the temperature rise due to the high temperature contents. When the first support member protrudes from the inner surface of the inner box, it connects to the inside of the outer box through the solid insulation material. Press the second support provided protruding from the surface, thereby expanding the inner box toward the membrane side. The inner box can only be inflated on the side opposite the membrane. This prevents membrane deformation. Therefore, the inner box must be heated and cooled repeatedly. Even if the membrane is returned to the It can prevent death. In addition, the insulation thickness of the vacuum insulation layer in the part corresponding to the rear wall has been increased. Therefore, this part can absorb the expansion of the inner box, and for this reason, the first and second The support can be constructed from a thin plate.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a vacuum insulation box according to an embodiment of the present invention.

FIG. 2 is a partially enlarged sectional view of the vacuum insulation box shown in FIG. 1;

FIG. 3 is a sectional view of a vacuum insulation box according to another embodiment of the present invention.

FIG. 4 is a sectional view showing an example of a conventional vacuum insulation box.

FIG. 5 is a partially enlarged sectional view of the vacuum insulation box shown in FIG. 4;

[Explanation of symbols]

1 Inner box 2 Outer box 3 Aperture 4 Vacuum insulation layer 5 Membrane 7 First support 8 Second support 9 Solid insulation material T insulation thickness

Claims (1)

[Scope of utility model registration request] Claim 1: An inner box and an outer box form a double-walled box with an opening on one side, a vacuum insulation layer is formed between the inner box and the outer box, and this vacuum insulation layer is sealed. In a vacuum insulated box body in which the opening side peripheries of an inner box and an outer box are connected by a membrane, first and second supports are installed on the inner surfaces of the inner box and the outer box near the membrane, and the depth of the box body is A solid heat insulating material is interposed between the first support and the second support, and the vacuum heat insulation A structure of a vacuum insulated box body characterized in that the insulation thickness of the layer corresponding to the rear wall of the box body is thicker than the insulation thickness of other parts.