JP4746899B2 - Method for manufacturing an insulated container - Google Patents

Description

  The present invention relates to a method for manufacturing a heat insulating container used in an industrial furnace, an incinerator, a power plant or the like. In particular, the present invention relates to a method for manufacturing a vacuum insulation container for a vacuum insulation panel.

  In recent years, high-performance heat insulation panels are required for energy saving and cost reduction.

  In the fields of semiconductors, electronic devices and the like, there is a particular need for heat-insulating panels that do not generate dust as the performance of components increases in size and size. In order to meet such a demand, various vacuum heat insulating containers and methods for manufacturing the same have been proposed.

  Even if the outer shell (case) is manufactured by drawing, pressing, or the like in a heat-insulated container whose inside is evacuated, a joint surface that necessarily needs to be vacuum-sealed remains. At present, the part is sealed by welding, or is sealed by heat fusion using an adhesive or an organic material. In particular, in a heat-insulated container used at 100 ° C. or higher, it is necessary to use a metal case, and sealing is performed by welding.

For example, in a powder vacuum insulator, a container obtained by deep-drawing a part of the first metal foil and a plate-like portion not subjected to processing are integrally formed, and after filling the container with a powdery filler, A cover is disclosed in which a cover made of a second metal foil covering both the container and the plate-like portion is covered, and the periphery of the cover and the first metal foil is vacuum-sealed by ultrasonic welding (patent) Reference 1). Further, a vacuum heat insulating container is disclosed in which a metal outer plate opposite to a metal outer plate is joined (seam welded) with an end portion sandwiched by a separator made of a honeycomb structure (Patent Document 2). reference).
Japanese Patent Application Laid-Open No. Sho 62-35197 (claim 1 in the left column on page 1, page 3, lines 1 to 7, line 1) JP-A-10-26294 (paragraphs [0018] and [0022], FIG. 1 in the detailed description of the invention)

  However, in the above-described prior art bonding, the thermal conductivity of the bonded portion or the bonded portion is higher than that of the other portion (for example, when a stainless steel container is welded with a copper-based brazing material, λSUS≈20 W / ( m · K) <λCu≈400 W / (m · K)), heat easily flows and the heat insulation effect is impaired. In addition, when heat is applied for joining, the plane of the welding allowance may be deformed (for example, when it is wavy) and may be welded without being completely sealed. .

  Accordingly, an object of the present invention is to obtain a method for manufacturing a heat insulating container that can follow the shape of the welded surface even when the weld surface is deformed and hardly causes a sealing defect.

  In order to solve the above-mentioned problems, in the present invention, a brazing material is installed between welded portions of two metal plates to be welded in a method for manufacturing a heat-insulated container formed by welding and vacuum-sealing a plurality of metal plates. And a method for producing a heat-insulated container that is brazed by hot press. Even if the welding surface is deformed by the brazing by this hot press, it is possible to follow the shape and hardly cause a sealing defect.

  Moreover, if it is set as the manufacturing method of the heat insulation container which provides the clearance gap in which the capillary phenomenon of a brazing material is uniformly expressed in the whole welding part in one or both of the upper and lower metal molds used for the hot press, Capillary phenomenon appears uniformly throughout the brazing process, and thermal deformation of the base material that occurs during brazing process can be suppressed due to the hot pressing. Good brazing is possible even with a thin metal plate.

  Moreover, if it is set as the manufacturing method of the heat insulation container applied when at least one of the welding parts of the two metal plates to be welded has a thickness of 0.05 to 10 mm, the gap is more preferably 1 to 500 μm. 10 to 100 μm, the capillarity is uniformly expressed throughout the brazing process, and the thermal deformation of the base material occurring during the brazing process can be suppressed because it is hot pressed. Good brazing is possible on relatively thin metal plates such as 0.05 to 1 mm and 0.1 to 0.6 mm.

  As described above, according to the present invention, even if the welded surface is deformed by brazing by hot pressing, a method for manufacturing a heat insulating container that can follow the shape and hardly cause a sealing defect can be obtained.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  1 and 2 relate to one embodiment. FIG. 1 is a longitudinal cross-sectional explanatory view showing a welding process of a method for manufacturing a heat insulating container, and shows a state before a brazing process by hot pressing. FIG. 2 is a longitudinal cross-sectional explanatory view showing a state after the brazing process by hot pressing, corresponding to the vertical cross-sectional explanatory view of FIG.

  1 and 2 illustrate a method for manufacturing a heat-insulating container in which a plurality of metal plates 1 and 2 are welded and vacuum-sealed to form a heat-insulating container. The brazing material 3 is installed between the welded portions 1a and 2a of the two metal plates 1 and 2 to be welded, and is placed between the upper and lower molds 4 and 5, and the state shown in FIG. Next, brazing is performed by hot pressing, and heaters 7 and 8 are provided in the upper and lower molds 4 and 5 used for the hot pressing, respectively. In one or both of the upper and lower molds 4 and 5, in this embodiment, the upper mold 4 is provided with a gap portion 6 in which the capillarity of the brazing material 3 appears uniformly over the entire welded portions 1 a and 2 a. .

  At least one of the welded portions 1a and 2a of the two metal plates 1 and 2 to be welded, here, both have a thickness of 0.1 to 0.6 mm. From the state of FIG. 1, the upper and lower molds 4, 5 are heated by the heaters 7, 8, the brazing material 3 is melted and a pressing force is applied by the upper and lower molds 4, 5 to braze between the welded portions 1 a, 2 a. It contacts and cools and it is in the state of FIG.

  The upper mold 4 is provided with a gap 6, and when the brazing material 3 develops a capillary phenomenon, the brazing material 3 spreads uniformly throughout the welded portions 1 a and 2 a. In this embodiment, the cross-sectional shape of the gap 6 is a tapered shape with the center rising and the right and left falling, but this shape can follow the deformed shape because the center is thick even if the weld surface is deformed. Therefore, it is a shape that hardly causes a sealing defect.

  In the above embodiment, a brazing material defined in JIS standards can be appropriately selected and used as the brazing material. When the exterior plate is a stainless steel material, a copper base, an aluminum base, a nickel base, and a silver base brazing material are used. A nickel-based brazing material is preferable from the viewpoint of heat resistance and corrosion resistance.

  In this way, an optimal space for brazing is provided and good brazing is possible by hot pressing with a die having a taper shape or a gap in one or both of the upper die and the lower die. In addition, brazing that can suppress deformation of the base material due to thermal stress is realized. By suppressing the deformation, it is possible to easily braze the thin metal plate.

  As described above, several embodiments of the present invention have been described. In the present invention, the material of the metal plate includes stainless steel, aluminum, aluminum alloy, and copper alloy, but stainless steel is preferable from the viewpoint of low thermal conductivity.

  In the present invention, the thickness of the metal plate may be 0.05 to 10 mm, but at least the plate thickness closer to the heat source is preferably as thin as possible to reduce heat conduction, but is too thin. However, since the expected strength cannot be obtained, it is specifically 0.05 to 1 mm, preferably 0.1 to 0.6 mm.

  Furthermore, regarding the atmospheric pressure (degree of vacuum) of the inner space of the heat insulating container, vacuum sealing means that the air pressure of the inner space of the heat insulating container is 0.1 to 1000 Pa. In the present invention, 100 to 600 ° C. In order to ensure the heat insulation performance in a relatively high temperature range, it is preferably 0.1 to 10 Pa, more preferably 0.1 to 1 Pa.

  The heat insulating material that can be inserted into the inner space of the heat insulating container has a thermal conductivity of 0.1 W / (m · K) or less, preferably 0.05 W / (m · K) or less, more preferably 0.02 W / (m · K) or less, for example, glass fiber heat insulating material, ceramic fiber heat insulating material, calcium silicate heat insulating material, rock wool, ceramic porous body, honeycomb material, metal multilayer reflector, etc. In the present invention, it is preferable to use a ceramic porous body or a ceramic fiber heat insulating material from the viewpoint of low thermal conductivity.

  Moreover, in this invention, hot press means adding the pressure of 50 KPa-5 MPa at the temperature of 500-1100 degreeC.

  Moreover, in this invention, the temperature conditions of a hot press should just be the temperature beyond the liquidus line of the brazing material to be used. Specifically, it is 600 to 1100 ° C. for a copper base, 500 to 700 ° C. for an aluminum base, 800 to 1100 ° C. for a nickel base, and 550 to 850 ° C. for a silver base.

  Further, regarding the atmosphere during brazing, the atmosphere capable of preventing oxidation is not particularly limited as long as it is an oxygen-free atmosphere, and specifically, hydrogen gas, carbon monoxide gas, carbon dioxide gas, nitrogen gas. It means the atmosphere of ammonia decomposition gas and inert gas (Ar, He). In the present invention, it is desirable to use hydrogen gas or stainless steel in which stainless steel can be easily reduced.

  INDUSTRIAL APPLICABILITY The present invention is useful as a method for manufacturing a vacuum heat insulating container for a vacuum heat insulating panel used in an industrial furnace, an incinerator, a power plant or the like.

BRIEF DESCRIPTION OF THE DRAWINGS It is longitudinal cross-sectional explanatory drawing which shows the welding process of the manufacturing method of the heat insulation container in one embodiment by this invention, and shows the state before the brazing process by hot press. It is longitudinal cross-sectional explanatory drawing corresponding to the longitudinal cross-sectional explanatory drawing of FIG. 1, and shows the state after the brazing process by hot press.

Explanation of symbols

  1, 2 Metal plate, 1a, 2a Welded part, 3 Brazing material, 4,5 Mold, 6 Gap part, 7, 8 Heater.

Claims (2)

In the manufacturing method of the heat insulating container that forms a vacuum seal by welding a plurality of metal plates,
A brazing material is installed between the welded portions of the two metal plates to be welded, and a gap in which the capillarity of the brazing material appears uniformly in the entire welded portion in one or both of the upper and lower molds used for hot pressing A method for manufacturing a heat-insulating container, characterized in that a part is provided and soldered by hot pressing. The method for manufacturing a heat insulating container according to claim 1 , wherein at least one of the welded portions of the two metal plates to be welded has a thickness of 0.05 to 10 mm.

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