JP2818430B2 - Manufacturing method of metal thermos - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for manufacturing a metal thermos, and enables a metal thermos with good heat insulation performance to be manufactured at low cost.

[Prior art and its problems] As a conventional metal thermos, as shown in FIG. 4, a double structure having a vacuum insulation layer 7 in a gap 4 between an inner bottle 1 and an outer bottle 2 is shown. Are provided.

In order to manufacture a metal thermos of this type, as shown in FIG. 5, an inner bottle 1 provided with a plating layer 5 made of a metal having a low emissivity on an externally evaluated surface, and an exhaust port 3 at the bottom. Provided,
In addition, the outer bottle 2 having a bottomed cylindrical shape provided with the plating layer 5 on the inner surface in the same manner as the inner bottle 1 is joined at the mouth so that the gap 4 is formed. Next, this is inverted, and a sealing material 8 such as a brazing material is intermittently arranged in the exhaust port 3, a sealing plate 6 is placed thereon, and is housed in a vacuum heating furnace. After the inside of the gap 4 is evacuated from the exhaust port 3 and the inside of the gap 4 is evacuated, the sealing material 8 such as a solid brazing material on the exhaust port 3 is melted and placed on the sealing plate 6. Is dropped by its own weight to seal the exhaust port 3 at the bottom of the outer bottle 2.

By the way, generally, an oxide film is generally formed on the surface of the metal constituting the inner bottle 1, the outer bottle 2, the sealing plate 6, and the like. These oxide films reduce the wettability of the sealing material 8 such as a brazing material. Therefore, when sealing the exhaust port 3, in order to improve the wettability of the sealing material 8, the oxide film on the surface of the outer bottle 2 and the sealing plate 6 is conventionally dissociated by high-temperature heating. It is the fact that it is done by. However, the dissociation condition of the metal oxide film is, for example, in the case of stainless steel suitably used for a metal thermos, heating at 950 ° C. or more under a pressure of 1 × 10 ⁻³ torr or less, and titanium which is preferably used for the purpose of weight reduction. In this case, heating at a high temperature of 1200 ° C. or more under the above-mentioned pressure is a factor that increases the production cost of a metal thermos.

Further, in the case of a titanium thermos in which the inner bottle 1 or the outer bottle 2 is made of titanium or a titanium alloy, when heated to the oxide film dissociation temperature, titanium reacts with the metal of the plating layer 5 because titanium is a very chemically active metal. However, there is also an inconvenience that an alloy having a high emissivity is formed and the heat retaining performance of the metal thermos is deteriorated.

The present invention has been made in order to solve the above-described problems, and after a low-temperature reducing metal material is joined to a peripheral portion of an exhaust port in advance, the exhaust port is vacuum-sealed, so that good heat retention performance is obtained. It is an object of the present invention to provide a method for producing a metal thermos at a low production cost.

[Means for Solving the Problems] According to the method for manufacturing a metal thermos according to claim 1 of the present invention, at least the outer bottle of the metal inner bottle and the outer bottle is made of titanium or a titanium alloy, and In manufacturing a metal thermos bottle having a void portion as a vacuum heat insulating layer, an inner bottle and an outer bottle each having an exhaust port are joined at the mouth to form a double structure, and then the exhaust port A sealing plate is placed on a peripheral portion of the sealing material via a sealing material, and the sealing plate is vacuum-heated in a vacuum heating furnace, and the inside of the gap is evacuated from the exhaust port to form a vacuum heat insulating layer. A method for manufacturing a metal thermos for sealing, characterized in that a low-temperature reducible metal material is previously bonded to at least the exhaust port side by diffusion bonding or welding on the exhaust port peripheral portion, In claim 2, a low-temperature reducing metal material is used for the sealing plate. According to a third aspect of the present invention, there is provided a method for manufacturing a metal thermos bottle in which at least an outer bottle of a metal inner bottle and an outer bottle is made of titanium or a titanium alloy and a gap between the inner and outer bottles is a vacuum heat insulating layer. In manufacturing, the inner bottle and the outer bottle each having an exhaust port provided on one of them are joined at the mouth to form a double structure, and then a sealing plate is provided on the periphery of the exhaust port via a sealing material. Is placed in a vacuum heating furnace, and the inside of the gap is evacuated from the exhaust port by vacuum heating in a vacuum heating furnace, and the exhaust port is sealed while forming a vacuum heat insulating layer. The use of a low-temperature reducible metal material for the sealing plate is a means for solving these problems.

In the manufacturing method according to the fourth aspect, each of the solving means is that the low-temperature reducible metal material is one selected from iron, copper, and nickel or an alloy thereof.

[Operation] In the manufacturing method according to the first aspect of the present invention, the low-temperature reducing metal material is formed in advance around the exhaust port, and in the manufacturing methods according to the second and third aspects, the low-temperature reducing metal material is provided on the sealing plate. In any of the manufacturing methods, the low-temperature reducing metal material dissociates the oxide film at a low heating temperature, so that the wettability of the sealing material can be improved and the exhaust port can be easily sealed. Can be stopped.

EXAMPLES Hereinafter, the present invention will be described in detail.

FIG. 1 shows an example of a metal thermos obtained by the production method according to claim 1 of the present invention. What is different from the one shown in FIG.
For example, an annular low-temperature reducing metal material plate 9 is provided around the exhaust port 3 formed at the bottom of the outer bottle 2. As shown in FIG. 2, such a thermos made of metal joins the inner bottle 1 and the outer bottle 2 at the mouth, and cools down the periphery of the outlet 3 provided at the bottom of the outer bottle 2. After bonding the reducing metal material 9, the sealing material 8 and the sealing plate 6 are placed, and this is vacuum-heated in a vacuum heating furnace and heated while evacuating the gap 4. It can be manufactured by sealing the exhaust port 3.

An outer bottle 2 having a bottomed cylindrical shape with a reduced diameter and an inner bottle 1 made of a bottomed cylindrical body having a smaller diameter than the outer bottle 2
Each of them can be manufactured from a metal or an alloy having high heat retention and high strength such as stainless steel or a titanium alloy, and a plating layer 5 is formed on the outer surface of the inner bottle 1 and the inner surface of the outer bottle 2 as necessary. I do. The plating layer 5 is a metal plating layer of silver or the like having a low emissivity, and can be formed by an electroplating method, or can be formed by a chemical plating method such as a silver mirror reaction. The plating layer 5 is formed on both the inner bottle 1 and the outer bottle 2 as shown in FIGS. 1 and 2, and formed on only one of the inner bottle 1 and the outer bottle 2. Alternatively, it may not be formed at all. In this embodiment, an exhaust port 3 is provided at the bottom of the outer bottle 2.
The exhaust port 3 may be provided at the bottom of either the inner bottle 1 or the outer bottle 2. Next, the inner bottle 1 is inserted into the outer bottle 2 and joined at the mouth. Further, a low-temperature reducible metal material 9 having a low dissociation temperature of an oxide film is annularly joined to the outer surface of the outer bottle 2 around the exhaust port 3. The low-temperature reducing metal material 9 may be a metal constituting the inner bottle 1 and the outer bottle 2, or a metal or alloy having an oxide film dissociation temperature lower than that of titanium or a titanium alloy, for example, iron 560 ° C and copper 470 ° C. In addition to nickel 680 ° C., tin, cobalt, lead and the like can be suitably used. In order to join the low-temperature reducing metal material 9 to the peripheral portion of the exhaust port 3 of the outer bottle 2, ordinary joining means such as diffusion joining or welding can be used. On the low-temperature reducing metal material 9, sealing materials 8, 8 made of a plurality of solid brazing materials are provided.
The sealing plate 6 is placed via. The number of constituents of the sealing members 8 is preferably at least two. In this case, a ventilation path for exhausting the gas in the gap portion 4 is secured between the sealing members 8. Can be. This sealing material 8,
8 can be appropriately selected depending on the types of the inner bottle 1, the outer bottle 2 and the low-temperature reducing metal material 9.
System alloy, Ag-Cu-Sn system alloy, Cu-P system alloy, g-Cu system alloy, Al system alloy, etc. can be used suitably. Further, the sealing plate 6 must be made of a metal or an alloy having good wettability with the sealing materials 8 and 8 even at a low temperature and a low dissociation temperature of an oxide film. The same as described above is preferable.

Next, while the outer bottle 2 is being heated, the inside of the gap 4 is evacuated from the exhaust port 3 and the periphery of the exhaust port 3 is heated. When vacuum evacuation is performed while heating, not only the inside of the gap portion 4 is depressurized, but also the gas adsorbed on the surface of the plating layer 5 is dissociated by heating, so that after the exhaust port 3 is sealed, a high degree of vacuum is obtained The vacuum heat insulating layer 7 can be formed. When the temperature is increased by heating, the low-temperature reducing metal material 9 and the sealing plate 6 are both made of a metal having a low oxide film dissociation temperature. 8 has good wettability. When the heating temperature further rises, the sealing materials 8 and 8 are melted, penetrate into the surface of the low-temperature reducing metal material 9 and the sealing plate 6 having improved wettability, and vacuum seal the exhaust port 3. be able to.

As described above, in the manufacturing method according to the first aspect of the present invention, the low-temperature reducing metal material 9 is previously joined to the periphery of the exhaust port 3 and a metal having a low dissociation temperature of the oxide film is obtained. In items 2 and 3, since the sealing plate 6 is made of a low-temperature reducing metal material, the oxide film is dissociated at a lower temperature than the conventional manufacturing method, and the wettability of the sealing material 8 is improved. Therefore, low-temperature sealing can be performed. Therefore, the manufacturing cost of the metal thermos can be reduced.

Further, in the manufacturing method according to the third aspect of the present invention, the low-temperature reducing metal material 9 is formed in advance on the periphery of the exhaust port 3 as described above, so that the wettability between the exhaust port 3 and the sealing members 8 is improved. Instead of using a low-temperature reducing metal material 9 for the sealing plate 6, thereby improving the wettability between the sealing plate 6 and the sealing materials 8.

When the sealing plate 6 is made of the low-temperature reducing metal material 9 in this way, the number of components of the metal thermos can be reduced, and the manufacturing process can be simplified and the manufacturing cost can be reduced.

Further, in a metal thermos manufactured by the manufacturing method of the present invention in which the outer bottle 1 is made of titanium or a titanium alloy, the heating temperature of the vacuum heating process can be lowered, so that the inner temperature is improved for the purpose of improving the heat retaining performance. It is possible to prevent the metal of the plating layer and titanium coated on the outer surface of the bottle and the inner surface of the outer bottle from becoming an alloy having high thermal conductivity during the vacuum heating process, and it is made of titanium with good heat retention performance You can easily get a thermos.

Further, in the manufacturing method according to the fourth aspect of the present invention, the low-temperature reducible metal material 9 is selected from iron, copper, and nickel, which are inexpensive and have good handleability and workability.
By using seeds or alloys thereof, the manufacturing process can be greatly simplified and the manufacturing cost can be reduced.

[Effect of the Invention] As described above, in the manufacturing method according to the first aspect of the present invention, the peripheral portion of the exhaust port is formed in advance with a low-temperature reducing metal material. Since the manufacturing method uses a low-temperature reducible metal material for the sealing plate, the heating temperature at the time of vacuum sealing can be lower than that of the conventional one, so that a metal thermos can be used at a low cost in any case. Can be manufactured.

Furthermore, in the thermos made of titanium or titanium alloy manufactured by the manufacturing method of the present invention, the heating temperature of vacuum sealing can be made lower than the activation temperature of titanium or titanium alloy. It is possible to prevent titanium or a titanium alloy constituting the bottle from reacting with a metal such as a plating layer to become an alloy having a high emissivity, and to easily obtain a lightweight and thermostable titanium thermos bottle having a good heat retaining performance. be able to.

Further, in the manufacturing method according to claim 4 of the present invention, one or more alloys selected from iron, copper, and nickel, which are inexpensive and have good handleability and workability, are used as the low-temperature reducing metal material. The manufacturing process can be simplified and the manufacturing cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view showing an example of a metal thermos obtained by the manufacturing method according to claim 1 of the present invention, and FIG. 2 is a diagram showing a metal thermos shown in FIG. FIG. 3 is an enlarged view of a main part of the metal thermos shown in FIG. 2, FIG. 4 is a schematic cross-sectional view showing an example of a metal thermos obtained by a conventional method, FIG. 5 is a schematic cross-sectional view showing a state before sealing the exhaust port of the metal thermos shown in FIG. DESCRIPTION OF SYMBOLS 1 ... Inner bottle, 2 ... Outer bottle, 3 ... Exhaust port, 4 ... Void, 6 ... Sealing plate, 7 ... Vacuum insulation part, 8 ... Sealing material, 9 ... Low temperature reduction Metallic material.

 ──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-61-106119 (JP, A) JP-A-61-106120 (JP, A) JP-A-64-49519 (JP, A) JP-A-64-106 49520 (JP, A)

Claims (4)

(57) [Claims] At least one of a metal inner bottle and an outer bottle is made of titanium or a titanium alloy, and at least one of them is used for manufacturing a metal thermos bottle in which a gap between the inner and outer bottles is a vacuum heat insulating layer. After joining the inner bottle and the outer bottle provided with an exhaust port at the mouth to form a double structure, a sealing plate is placed on the periphery of the exhaust port via a sealing material, and A method for producing a metal thermos for vacuum heating in a vacuum heating furnace and evacuating the inside of the gap from the exhaust port to seal the exhaust port while forming a vacuum heat insulating layer. A method for manufacturing a metal thermos, wherein a low-temperature reducible metal material is previously bonded to at least the exhaust port side by diffusion bonding or welding. 2. The method according to claim 1, wherein a low-temperature reducing metal material is used for the sealing plate. 3. A method for manufacturing a metal thermos bottle in which at least an outer bottle of a metal inner bottle and an outer bottle is made of titanium or a titanium alloy and a space between the inner and outer bottles is a vacuum heat insulating layer. After joining the inner bottle and the outer bottle provided with an exhaust port at the mouth to form a double structure, a sealing plate is placed on the periphery of the exhaust port via a sealing material, and A method for producing a metal thermos for vacuum heating in a vacuum heating furnace and evacuating the gap from the exhaust port to seal the exhaust port while forming a vacuum heat insulating layer, wherein the sealing plate has a low temperature. A method for producing a metal thermos, comprising using a reducing metal material. 4. The thermos according to claim 1, wherein the low-temperature reducing metal material is one selected from iron, copper and nickel or an alloy thereof. Manufacturing method.