JPS623087Y2 - - Google Patents

Description

[Detailed description of the invention] This invention is a vacuum insulated container, such as a metal thermos flask.
This invention relates to the neck structure of a vacuum insulated container that has particularly low heat loss in the neck and does not cause a decrease in the degree of vacuum in the insulated space, in relation to improving the neck structure of cryostats, insulated lunch boxes, etc.

Vacuum insulation containers are generally widely used because of their excellent insulation properties. However, conventional metal vacuum insulated containers have the disadvantage that the excellent heat insulating properties of vacuum insulation cannot be fully utilized because a considerable amount of heat enters or dissipates from the neck of the container.

In order to solve these problems, efforts have been made to reduce the thickness of the metal plate constituting the container neck as much as possible. However, there is a certain limit to reducing the thickness of the metal plate in terms of the mechanical strength of the container neck, and it has not yet been possible to sufficiently reduce heat loss from the container neck.

On the other hand, research has recently been underway to reduce heat loss at the neck of the container by replacing the metal plate with a synthetic resin plate for the inner layer of the neck of the container. This is because the synthetic resin material has a low thermal conductivity, so the plate thickness at the neck can be made relatively large. but,
Synthetic resin plates have extremely high gas permeability compared to metals, and the resin itself releases a large amount of internal gas, making it impossible to maintain the vacuum level in the insulation space at a specified value over a long period of time. There is a fundamental flaw.

Therefore, the inventor of the present invention came up with the idea of coating the surface of a synthetic resin plate with metal by vapor deposition or plating, and has repeatedly conducted various experiments on vacuum insulation containers using this coating. As a result, if the metal layer is 10 μm or less, it is impossible to prevent gas permeation and to sufficiently block internal gas from the synthetic resin plate, and in order to obtain practical performance,
It was learned that the thickness of the metal layer is required to be 50 μm or more.

It was also found that the plating metal layer had relatively many pinholes and was not effective enough to sufficiently reduce the amount of internal gas released.

Furthermore, when forming a metal layer by vapor deposition,
This causes the problem of softening of the synthetic resin. That is, when a metal with a layer thickness of 50 μm or more is deposited on the surface of a synthetic resin, the heat of solidification of the metal solidifying on the surface layer of the resin causes the synthetic resin to soften. Furthermore, it has been found that it takes about 20 to 30 hours to deposit metal to a layer thickness of about 50 μm while preventing softening of the resin, which poses many practical problems.

Through various development experiments and their results as described above, the inventor of the present application has applied synthetic resin such as PBT or polyethylene with a thickness of 0.5 mm to 2 mm to one side of a thin metal plate with a thickness of 0.01 mm to 0.6 mm, using an epoxy resin. By using an adhesive or the like, or by blow molding the resin side, heating it, and fixing it by welding, and using the metal side of the laminate as the vacuum side and using it for the neck of a vacuum insulated container,
It has low gas permeability and completely blocks internally emitted gas from the synthetic resin material, allowing it to maintain a high degree of vacuum for a long period of time, and significantly reducing heat loss in the neck area. We have developed a neck structure for vacuum insulated containers that can easily obtain the mechanical strength of .

Hereinafter, the details will be explained based on each embodiment of the present invention shown in FIGS. 1 to 4.

It should be noted that the present invention is not limited to the configurations of the embodiments, but may be modified as appropriate without departing from the gist thereof. Furthermore, it goes without saying that the laminate used in the "neck structure of a vacuum insulated container" according to the present invention can also be used as a plate material and a frame material for a vacuum insulated panel.

FIG. 1 shows a first embodiment of the present invention, and is a longitudinal sectional view of a lunch box using a vacuum insulation board 1. As shown in FIG. FIG. 2 is a partially enlarged sectional view of the neck.
In the figure, 2 is the outer layer plate that constitutes the vacuum insulation board 1, and a stainless steel plate with a thickness of 0.6 mm is used, and its external dimensions are 175 mm in width, 250 mm in length, and 55 mm in height. It is formed into a rectangular parallelepiped cylinder with one side open. In addition, 3 is a heat insulating spacer, which is made of hard glass with a thickness of 2 mm and a height of 3 mm.
They are used stacked in tiers.

4 is a laminated plate formed by fixing a synthetic resin layer 4b to one side of a thin metal plate 4a, and in this embodiment, one side of a stainless steel plate with a thickness of 0.1 mm is
Laminated board 4 with 1mm thick polycarbonate adhered to it
is used as the inner layer of the vacuum insulation board 1. The laminated plate 4 is formed into a rectangular parallelepiped cylinder with one side open like the outer layer plate 2, and by inserting it into the outer layer plate 2 with a spacer 3 interposed, the outer dimension and thickness can be reduced. The main body of the lunch box is composed of a vacuum insulation board 1 with a diameter of 10 mm.

The laminated plate 4 is made by rolling a 0.1 mm thick stainless steel plate into a rectangular parallelepiped shape and soldering the seams to one end of a rectangular cylindrical shape, and a press-molded rectangular cap with a depth of about 5 mm attached by soldering. It is manufactured by applying an epoxy adhesive to the surface of a polycarbonate cylinder of the same shape that is molded into a slightly smaller size into a rectangular parallelepiped cylinder, and then inserting it and allowing the adhesive to harden. . In addition, regardless of the adhesive mentioned above,
Of course, the rectangular parallelepiped cylinder made of stainless steel may be fixed from the outside with a mold, and polyethylene or the like may be molded into the cylinder in close contact with the stainless steel by blow molding, and then heated and welded. be.
Further, in this embodiment, all the inner layers of the vacuum insulation board 1 are formed of the laminate plate 4 of stainless steel and polycarbonate, but the area near the opening 5 of the lunch box, that is, the urethane insulation material The laminated plate 4 is used only in the part where 7 is included, and the thickness is adjusted in other parts.
A stainless steel plate of about 0.4 to 0.5 mm may also be used.

6 is an inner box to be inserted into the lunch box body, and is made of a synthetic resin material such as polycarbonate that does not deposit harmful substances, and one side of the inner box has a thickness of 30 mm.
A urethane heat insulating material 7 of mm is fixed to the lunch box body so that the opening 5 of the lunch box body is closed.
8 is a lid of the inner box 6.

Next, the heat insulation properties of the neck structure according to the present invention will be explained based on the lunch box described above.

First, for comparison, the heat loss of a vacuum insulated lunch box with the exact same configuration as the lunch box shown in Figure 1, but with the only inner layer made of 0.4 mm stainless steel plate, is as follows: Become. In addition, the following heat loss amount Q
is a calculated value, but it has been demonstrated that this value almost completely agrees with the measured value.

Total heat loss Q = 6.8kcal/H Breakdown (a) Heat transfer loss from insulation spacer 3 Q ₁ = 2.1kcal/H (b) Heat transfer loss from urethane insulation material 7 Q ₂ = 0.1kcal/H (c ) Heat transfer loss from neck A Q ₃ = 2.7 kcal/H (d) Heat loss due to radiation Q ₄ = 1.5 kcal/H (e) Molecular heat conduction in vacuum insulation (degree of vacuum 1×10 ^{-4 Torr} ) = Q ₅ Negligible As is clear from the above results, the heat transfer loss _Q3 from the neck A includes approximately 40% of the total loss Q, and in this type of vacuum insulated container, the loss
Reducing _Q3 has become the most important issue.

On the other hand, in the vacuum insulated lunch box shown in FIG. 1 having the neck structure according to the present invention, the heat transfer loss _Q3 at the neck A is reduced to approximately 1/4 (≒0.7kcal/H),
As a result, the total heat loss amount Q becomes 4.8 kcal/H. That is, it becomes possible to reduce the amount of heat loss by approximately 30%.

The thickness t of the stainless steel plate 4a needs to be at least 0.01 mm or more in order to maintain the degree of vacuum as described above, and if the thickness t is 0.6 mm or more, this type of thermal lunch box As for the box, the insulation performance is almost the same as when the whole box is insulated with foamed urethane, and the advantage of vacuum insulation is lost.

In addition, metal thin plates 4 can be used for metals other than stainless steel plates.
A, but if the thermal conductivity is nearly twice that of a stainless steel plate (14kcal/mH℃), the benefits of the neck structure will be diminished, so materials with a thermal conductivity of 30kcal/mH℃ or less are recommended. is desirable.

FIG. 3 shows the main part of a second embodiment of the present invention, which is applied to a cylindrical all-metal thermos flask. FIG. 4 is a partially enlarged sectional view of the neck.

In the figure, 9 and 10 are an inner tank and an outer tank made of stainless steel. The neck A of the heat insulating container is made of a laminated structure in which so-called FRP, which is made of glass fiber and epoxy resin, is laminated to a thickness of 2 mm on the inner surface of a cylindrical body made of a 0.1 mm thick stainless steel plate 4a that has been processed in advance into a cylindrical shape. It is composed of a plate 4, and both ends of the laminated plate 4 are fixed to the ends of an inner tank 9 and an outer tank 10, respectively, by soldering.

The thermal conductivity of the above FRP4b is 0.2kcal/mH℃
Even if the thickness of the stainless steel plate 4a is made 20 times (2 mm), the heat transfer loss is negligible, and the mechanical strength of the container neck A can be adjusted to the desired value by the FRP 4b. can be retained. Furthermore, it is of course possible to use other synthetic resin materials with low thermal conductivity in place of FRP.

As described above, despite the extremely simple structure of the present invention, it is possible to significantly reduce heat loss at the container neck A, which has traditionally been considered to be the weakest point of a metal vacuum insulated container.

Furthermore, the mechanical strength of the container neck can be maintained by the synthetic resin layer, and the thin metal plate completely blocks gas permeation, so that the degree of vacuum does not decrease over time. Thus, the present invention has excellent practical utility.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing a first embodiment of the present invention, in which the present invention is applied to a vacuum insulated lunch box. FIG. 2 is an enlarged sectional view of section B in FIG. 1. FIG. 3 is a longitudinal sectional view showing a second embodiment of the present invention. FIG. 4 is an enlarged sectional view of section C in FIG. 3. A... Neck of vacuum insulation container, 1... Vacuum insulation board, 2... Outer layer plate, 3... Heat insulation spacer, 4...
Laminated plate, 4a... Metal thin plate, 4b... Synthetic resin layer, 5... Opening, 6... Inner box, 7... Urethane insulation material, 8... Inner box lid, 9... Inner tank, 10 ……
Outer tank.

Claims (1)

[Claims for Utility Model Registration] (1) Laminated plate 4 is formed by closely adhering a synthetic resin layer 4b to one side of a thin metal plate 4a, and the neck of a heat-insulating container is made with the thin metal plate 4a of the laminated plate 4 on the vacuum side. A neck structure of a vacuum insulated container characterized by comprising A. (2) The neck structure of a vacuum heat-insulating container according to claim 1, which uses a thin metal plate 4a having a thermal conductivity of 30 Kcal/mH°C or less and a thickness t of 0.01 mm to 0.6 mm.