JP2842467B2 - Manufacturing method of vacuum insulated container - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a vacuum insulated container.

[0002]

2. Description of the Related Art Conventionally, as a structure of a heat insulating wall such as a baking furnace for heat treatment which performs higher-order heat insulation, the inside of the heat insulating wall consisting of the inner and outer walls is made into a closed space, and an inorganic fiber mat is housed therein, and then vacuum evacuated and sealed. A heat insulating wall is known (for example, Japanese Utility Model Laid-Open No. 62-54396). This kind of heat-insulating wall provides a high-order heat-insulating effect by synergism between the inside vacuumed atmosphere and the heat-insulating effect of the densely packed inorganic foamed powder.
It is said that a wall with a thickness of about 5 cm can insulate at a temperature difference between room temperature and 300-400 ° C.

[0003] By the way, when the heat insulating body is filled with the mat in the heat insulating space and the heat insulating wall is evacuated, if the heat insulating wall is evacuated, the heat insulating wall is caused by the difference in pressure between the inside and outside due to uneven filling of the fiber mat or the compressive deformation property of the fiber mat. Dent deformation may occur. In view of such a problem, an organic binder is contained as an inorganic fiber mat sealed in the heat insulating space, and compressed to a thickness almost equal to the heat insulating space of the heat insulating wall by compressing at a pressure equal to the atmospheric pressure with respect to vacuum. Using a compressed and cured material, insert this heat insulating mat into the heat insulating space, then heat the heat insulating wall to the decomposition temperature of the organic binder in the presence of air to gasify,
After sucking and discharging this gas, a method of evacuating the heat-insulated space was proposed (for example, Japanese Patent Application No. 3-104735).

[0004] There are two methods for inserting the above-mentioned inorganic fiber heat insulating mat into the heat insulating wall. The first method is to use inorganic fiber which is slightly thinner than the heat insulating wall and whose density is sufficiently increased to withstand the atmospheric pressure. A method of inserting a heat insulating mat into a heat insulating wall previously formed in a double structure, then sealing the heat insulating wall and evacuating the inside,
The second method is to form an inner container of a heat insulating wall that forms a double wall, place a low-density inorganic fiber heat insulating mat around it, apply a metal plate that forms the outer wall to the surroundings, and apply atmospheric pressure. A method has been adopted in which the inorganic fiber heat insulating mat is compacted to a density that can withstand it, and in this state, the outer wall metal plates are welded to each other to complete the heat insulating container.

[0005]

However, in the first method, since the inorganic fiber heat insulating mat is filled in the heat insulating wall, it is necessary to make the layer thickness smaller than the heat insulating wall thickness. Has a drawback in that the outer wall is dented by atmospheric pressure when subjected to a vacuum treatment, resulting in an undesired appearance.

According to the second method, since the outer wall is formed while the inorganic fiber heat insulating mat is compacted to a predetermined density, there is no problem as described above. However, it takes a very long time to form the outer wall. Since the outer walls are welded to each other after the material has been filled, a leak-free welding technique that can withstand vacuum in the presence of gasifying foreign substances such as binders is required, requires advanced welding techniques, is difficult to implement, and reduces productivity. There was a bad problem.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and when an inorganic fiber heat insulating mat is sealed in a heat insulating wall of a heat insulating container and evacuated, the outer wall does not dent due to atmospheric pressure. Further, it is an object of the present invention to obtain an improved method for manufacturing a vacuum insulated container capable of rapidly manufacturing a vacuum insulated container.

[0008]

That is, a method of manufacturing a vacuum heat insulating container according to the present invention provides a vacuum heat insulating container 1 in which a heat insulating mat 2 is inserted into a double wall consisting of an outer wall 1A and an inner wall 1B and the inside is evacuated. The outer wall 1A and the inner wall 1B
Two large and small containers consisting only of
After the inorganic fiber heat insulating mat 2 slightly thicker than the inner wall thickness of the double wall having a density capable of withstanding the atmospheric pressure is disposed on the inner surface of the inner wall container A, the inner wall container 1B is replaced with the inner wall container 1A.
B is press-fitted into the outer wall container 1A via an insertion jig 3 fitted into B, and then the joining edge 1C between the inner wall container 1B and the outer wall container 1A is sealed to evacuate the inside. Things.

[0009]

According to the present invention, in manufacturing the heat insulating container, first, two large and small containers each having only the outer wall 1A and the inner wall 1B are formed in advance, and the inorganic fiber heat insulating mat 2 is arranged on the inner surface of the outer wall container 1A. 1B is inserted via the jig 3. In this case, since the inner and outer containers are formed in advance, assembly by welding can be easily performed, and leakage and the like can be easily checked.

Since the inner wall 1B is inserted into the inner surface of the outer wall 1A, the forced insertion is possible even if the thickness of the inorganic fiber heat insulating mat 2 inserted therebetween is slightly larger than the thickness of the heat insulating wall. , And proper insertion is achieved by the insertion. Since the inner wall container 1B may receive a compressive force from the surroundings at the time of insertion and may be deformed, the insertion jig 3 having substantially the same internal volume is inserted in a fitted state. Then, in this state, the joining edge 1C between the inner and outer walls is welded.
Since the welding line at this time is only the portion along the joining edge 1C, the number of welding operations is small, and the sealing operation is completed with fewer welding steps.

[0011]

Next, an embodiment of the present invention will be described. Figure 1
FIG. 3 is a sectional view of an embodiment of the present invention.

In a heat insulating container 1 having a width of 1000 mm, a depth of 600 mm, a height of 1700 mm and a heat insulating layer of 40 mm, first, the inner surface has a width of B1000 m
m, depth 600mm, height H1700mm outer wall container 1A and outer surface width b920mm, depth 520mm, height h1660mm height inner wall container 1B
Was molded. Then, 10 parts by weight of a phenol resin (trade name, manufactured by Dainippon Ink and Chemicals, Inc.) is uniformly formed on a thick rock wool mat made of rock wool fiber having a fiber diameter of 5 μm to 8 μm in a non-pressurized state. (Bryofen) by spraying and impregnating it, and pressurizing it while heating it with a press machine at a pressure of ² kg / cm ² to consolidate it to a density that resists the atmospheric pressure of 1 mm thick and 41 mm thick against a set vacuum layer thickness of 40 mm. An insulating mat 2 was formed.

As shown in FIG. 1, the heat insulating mat 2 is uniformly arranged on the inner surface of the outer wall container 1A, and key points are fixed with an adhesive.
The insertion jig 3 was fitted into the inner wall container 1B, and the inner wall container 1B was pressed into the outer wall container 1A via the jig 3 as shown in FIG. Then, as shown in FIG.
The joining edge 1C of B was welded to seal the inside, and immediately after the insertion jig 3 was pulled out, it was transferred to a vacuum exhaust device (not shown) to perform vacuum exhaust inside the heat insulating wall.

[Comparative Example 1] Two inner and outer walls formed in a square shape around an integrated bottom plate with an insulating mat sandwiched between an outer bottom plate and an inner bottom plate are fixed upright by welding, and an insulating space therebetween. A slightly thinner insulating mat of the same material as used in Example 1 was inserted and the opening was sealed to produce an insulating container.

Comparative Example 2 A low-density heat-insulating mat is arranged on the entire outer periphery of the same inner wall container 1B used in Example 1, and a metal plate constituting the outer wall is applied from the outer surface thereof to consolidate the outer wall. The plates were welded together and finally the opening between the inner and outer walls was sealed to produce an insulated container.

When the time required for manufacturing the heat insulating container was measured for the above Example and Comparative Examples 1 and 2, the work was completed in 1 hour in the case of the Example, whereas the Comparative Example 1 was filled with the heat insulating mat. In Comparative Example 2, it took 4 hours to weld the outer wall in the compacted state because it took more time than in Examples. Also, when the appearance of the obtained vacuum insulated container was compared, the example exhibited a normal appearance, whereas the comparative example 1 had a dent deformation on the outer surface, and the comparative example 2 had a noticeable welding mark. Also, the appearance was inferior to the examples.

[0017]

As described above, according to the method for manufacturing a vacuum insulated container of the present invention, the time required for manufacturing is reduced to one third of that of the conventional case, and the production efficiency is greatly improved, and at the same time the inner and outer walls 1A are improved. Since 1B is manufactured in advance in a factory, a heat-insulating wall having good airtightness can be easily manufactured. In addition, the number of finally required welding portions is small, and welding is performed at a portion where there is no heat insulating material on the back surface, so that the welding operation is easily and quickly performed.

[Brief description of the drawings]

FIG. 1 is a sectional view showing the steps of an embodiment of the method of the present invention.

FIG. 2 is a sectional view showing the steps of an embodiment of the method of the present invention.

FIG. 3 is an enlarged sectional view of a main part showing steps of an embodiment of the method of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Insulated container 1A ... Outer wall container 1B ... Inner wall container 1C ... Joining edge 2 ... Insulating fiber insulation mat 3 ... Insert jig

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁶ , DB name) F16L 59/00-59/22 B65D 81/38 F25D 23/06

Claims (1)

(57) [Claims] 1. A method for manufacturing a vacuum insulated container 1 in which a heat insulating mat 2 is inserted into a double wall composed of an outer wall 1A and an inner wall 1B and the inside is evacuated, wherein two large and small containers each comprising only the outer wall 1A and the inner wall 1B are provided. Is formed on the inner surface of the outer wall container 1A, and the inorganic fiber heat insulating mat 2 is slightly thicker than the inner surface thickness of the double wall having a density capable of withstanding atmospheric pressure.
Is disposed, the inner wall container 1B is press-fitted into the outer wall container 1A via the insertion jig 3 fitted into the inner wall container 1B, and then the joining edge between the inner wall container 1B and the outer wall container 1A is inserted. A method for manufacturing a vacuum insulated container, comprising sealing 1C and evacuating the inside.