JPS61195261A - Manufacture of heat-insulating panel - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention is based on F! The present invention relates to a method of manufacturing a heat insulating panel suitable for forming a heat insulating wall of an iU or a refrigerator.

[Technical background of the invention]

Conventionally, vacuum insulation panels have been used in conjunction with urethane foam for the insulation walls of refrigerators, for example, but these vacuum insulation panels are made by welding the periphery of a thermoplastic resin film treated with metal vapor deposition. It is composed of an outer shell formed in the shape of a shape, and a filling made of powdered or granular fat filled inside the outer shell, and the inside of the outer shell is
A vacuum is created by pulling a vacuum at the stage of forming this into a cloth.

[Problems with background technology]

By the way, when this type of vacuum insulation panel is applied to a heat insulation wall of a refrigerator, for example, it is used in combination with a heat insulation layer made of urethane foam. and,
In this case, the insulation layer 6r of the vacuum insulation panel remains constant even at extremely low temperatures, and in the case of urethane foam, the internal foaming agent condenses and liquefies at extremely low temperatures, resulting in a decrease in insulation performance. For this reason, it is being considered to place vacuum insulation panels inside the insulation wall (on the low-temperature side). However, in the vacuum insulation panel of the conventional configuration, the surface shape of the outer shell is limited to a planar shape.
When using the inside of the insulation wall of a cold R refrigerator, the convex part of the inner box located further inside the vacuum insulation panel for supporting shelves, etc. will not remain in a hollow state. This leads to a decrease in the strength of the structure, which has the disadvantage of requiring reinforcement, which complicates the overall structure. However,
If a vacuum insulation panel is placed on the outside of the insulation wall and a heat insulation layer made of urethane foam is placed on the inside, the overall insulation performance will decrease due to the aforementioned phenomenon in which the insulation performance of urethane foam decreases at extremely low temperatures. cause problems.

[Purpose of the invention]

The present invention has been made in view of the above points, and its purpose is to allow the shape of the outer shell to be freely formed to suit the storage room, and to place it inside the heat insulating wall (on the low temperature side) to improve the overall heat insulation. It is an object of the present invention to provide a method of manufacturing a heat insulating panel that can prevent the overall structure from becoming complicated even when performance is improved.

[Summary of the invention]

The present invention involves forming a space between a first plate-like body and a second plate-like body, one of which has a predetermined shape suitable for a storage chamber, by overlapping the bodies and connecting their peripheries. A step of filling the space with a filler made of powder or granules, and a step of evacuating the space or filling the space with a gas having a low boiling point and low thermal conductivity were performed sequentially. Later, by performing a step of hermetically sealing the space, the shape of the outer shell can be freely set.

[Embodiments of the invention]

A first embodiment of the present invention will be described below with reference to FIGS. 1 to 6.

In Fig. 2, 1 is a heat insulating box for a refrigerator, for example, which is between an outer box 2 and an inner box 4 with four vacuum heat insulating panels 6 as described below pasted on both left and right sides at the top and bottom. It has a heat insulating wall 6 filled with foamed urethane foam 5, and a storage chamber A therein (not shown) is divided into a freezing room and a refrigerator room. Incidentally, a protrusion 4a is formed on the side surface of the inner box 4 to support a shelf (not shown). Now, as shown in FIG. 1, the vacuum insulation panel 6 has a substantially rectangular shape as a whole and has a protrusion 7 on the inner surface that fits into the cavity on the back side of the convex part 4a. Inside the outer shell 8, a filling 9 made of powder or granules is housed. Further, such a vacuum insulation panel 3 is configured so that the inside of the outer shell 8 is maintained in a vacuum state through the steps described below, thereby exhibiting a sufficient insulation effect.

The vacuum insulation panel 3 is manufactured through the steps shown in FIG. 3, and the manufacturing method will be described below.

That is, in the connection step shown in FIG. 3(a), the first plate-shaped body, which is the metallized film 1o, and the second plate-shaped body, which has a shape that conforms to the storage chamber A and thus the inner box 4, are connected. The metal vapor-deposited multilayer sheet 11 is stacked on top of the other, and three of the four peripheral sides are welded to form a space between them (see FIG. 3(b)). Here, the metal vapor-deposited multilayer sheet 11 is a multilayer sheet in which at least one layer is made of metal or a metal vapor-deposited sheet, and is formed into the shape described above by shaping with hot acid.

In the material filling step (see FIG. 6(b)) that follows the connecting step, the powder or the filling 9 made of the powder is packed into the outer shell 8.
It is stored in the space inside the outer shell 8 through the opening 8a which has not yet been welded. Then, in the pressurizing and vacuuming process shown in FIG.
and an upper mold 15 consisting of a fixed mold 13 and a movable upper mold 14, and while pressurizing the air inside the outer shell 8 is discharged to the outside through the opening 8a. Evacuate the space. In this case, in order to keep the shape of the protrusion 7 of the outer shell 8 intact, the flat part of the outer shell 8 is moved by the movable upper mold 14.
Apply more pressure. Thereafter, the welding and sealing process shown in FIG. 3(d) is performed to weld the opening 8a of the outer shell 8 and the outer shell 8.
Airtightly seal the internal space.

The vacuum insulation panel 3 is thus formed.

According to this embodiment, the following effects can be obtained. That is, since the outer shell 8 is formed by welding the metallized film 10 and the metallized multilayer sheet 11 having a shape that matches the inner box 4, the protrusion 4a of the inner box 4 for supporting shelves, etc.
It is possible to form a vacuum insulation panel 6 having a protrusion 7 that can be fitted into the cavity on the back side of the vacuum insulation panel 6. In this way, the hollow convex portion 4a can be reinforced without using a separate member, and the overall structure can be simplified as a result. Of course, since the vacuum insulation panel 6 was provided inside the insulation wall 6 (on the low temperature side), the temperature characteristics of the thermal conductivity of the urethane foam 5 (the thermal conductivity decreases as the temperature decreases).

When the temperature drops below the liquefied humidity of the foaming agent during foaming of the urethane foam 5, the thermal conductivity remains at a constant value, that is, the insulation performance decreases) and the temperature characteristics of the thermal conductivity of the vacuum insulation panel 3 (when the temperature As the thermal conductivity decreases, the thermal conductivity also decreases, that is, the thermal insulation performance does not decrease. In addition, since the vacuum insulation panel 6 is provided on the low temperature side of the insulation wall 6, there is no need to provide the highly hygroscopic urethane foam 5 on the low temperature side, which can reduce moisture absorption and deteriorate the insulation properties of the urethane foam 5 over time. can be reduced. Moreover, since the portion of the heat insulating wall 6 that contacts the outer box 2 side is filled with the urethane foam 5, the heat radiation pipe can be disposed in a conventional manner. Furthermore, since the outer shell 8 was formed by welding the metallized film 10 and the metallized multilayer sheet 11, the vacuum insulation panel 3 of the inner box 4
It can prevent the part to which the adhesive is pasted from being thermally deformed during urethane foaming, or from cracking or denting due to urethane shrinkage.

In the above embodiment, the vacuum insulation panel 3 may be constructed as a part of the inner box 4, and in this case, a shelf is placed directly on the protrusion 7 of the vacuum insulation panel 6.

FIG. 4 shows a second embodiment of the present invention, and a method for manufacturing a vacuum insulation panel according to this embodiment will be explained below. In the material filling process shown in FIG. 4(a), the first
a rectangular metal plate 16 that is a plate-like body; and a metal plate 17 that is a second plate-like body that is rectangular as a whole and is formed into a shape that conforms to the inner box 4 by press molding or the like. A filler 18 made of powder or granules is filled between the two. Incidentally, a substantially cylindrical tube portion 19 having a ventilation hole 19a is provided in the center of the metal plate 16 and protrudes outward.
A filter 20 is attached to the air passage. In the welding process (see Fig. 4 (h) J) subsequent to the material filling process, the four peripheral sides of the metal plates 16 and 17 are welded to form an outer shell 21, and the inside of this outer shell 21 is Filler 1 in the space
8 is in a sealed state. After this, Figure 4 (C)
Execute the vacuuming process shown in . In this evacuation step, the air inside the outer shell 21 is exhausted to the outside through the vent hole 19a, thereby evacuating the space inside the outer shell 21. In this case, if the vacuum is drawn while heating the outer shell 21, the vacuum can be drawn more efficiently and in a short time. After completing the evacuation process, the welding sealing process shown in FIG. Keep the section under vacuum.

The second embodiment also has the same effects as the first embodiment, but in particular, since the outer shell 21 is constructed by welding the metal plates 16 and 17, the ability to maintain a vacuum state is improved. Excellent vacuum insulation panels can be manufactured.

In the above embodiment, the ventilation hole 1 is provided in the metal plate 16.
Although the joint portion 19 having the shape 9a is provided, a metal plate 16 is provided instead.
．． When welding 17, one side may be left and this may be used as an opening for vacuuming. Also, although the metal plate 16.17 was welded after storing the filling 18, the metal plate 16.1 was instead welded.
7 may be welded first, then the filler 18 may be housed in the outer shell 21 through the ventilation hole 19a, and then the filter 20 may be attached.

Furthermore, in the first and second embodiments described above, the vacuum insulation panel was provided on the side surface of the insulation wall 6, but it may be additionally provided on the ceiling surface, back surface, or bottom surface of the insulation wall 6. An integral vacuum insulation panel may be provided throughout.

In addition, the present invention is not limited to the embodiments described above and shown in the drawings, and the insulation wall may be formed only with a vacuum insulation panel without using urethane foam, and the insulation wall of a refrigerator may be used. However, it may be applied to an insulated door instead.Furthermore, instead of vacuuming, a gas with a low boiling point and low thermal conductivity (for example, xenon gas) may be filled, within the scope of the gist. It can be implemented with various modifications.

〔Effect of the invention〕

As is clear from the above description, when manufacturing a heat insulating panel, the present invention allows the shape of the outer shell to be freely formed to match the storage room. This has the effect of suppressing the complexity of the overall structure even when the heat insulation performance of the structure is improved.

[Brief explanation of drawings]

Figures 1 to 3 show a first embodiment of the present invention, with Figure 1 being a perspective view of a vacuum insulation panel partially cut away, and Figure 2 being a longitudinal sectional front view of a refrigerator insulation box. , FIG. 3 is a vertical sectional view showing the manufacturing process of a vacuum insulation panel, and FIG. 4 is a view corresponding to FIG. 6 showing a second embodiment of the present invention. In the drawings, 1 is a heat insulating box, 3 is a vacuum heat insulating panel, 7 is a protrusion, 8 is an outer shell, 9 is a filler (the powder region is a granular material), and 10 is a metal-deposited film (the first plate-shaped 11 is a metal vapor-deposited multilayer sheet (M2 plate-like body), 16 is a metal plate (first plate-like body), 17 is a metal plate (second plate-like body), 18 is a filler (
(powder or granule), 21 is the outer shell, and A is the storage chamber.

Claims (1)

[Claims] 1. A first plate-like body and a second plate-like body, one of which has a predetermined shape suitable for a storage room, are overlapped and their peripheries are connected to form a space between them, and the space is a step of filling with a filler made of powder or granules;
A method for producing a heat insulating panel comprising the steps of: evacuating the space or filling the space with a gas having a low boiling point and low thermal conductivity; and hermetically sealing the space.