JP2702549B2 - Manufacturing method of titanium thermos - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing a titanium thermos which is lightweight and has excellent heat retaining performance.

[Related Art] Conventionally, various types of metal thermos made of stainless steel having high strength and good heat insulation performance have been proposed and put into practical use. This is excellent in heat retention performance and does not break, but has the disadvantage of being heavy and inconvenient to carry. Also, stainless steel has insufficient corrosion resistance,
There is also a risk of corrosion when storing salty foods and drinks.

For these reasons, thermos bottles made of lightweight, high-strength, highly corrosion-resistant titanium or a titanium alloy (hereinafter, simply referred to as titanium) have been proposed.

In such a thermos made of titanium, a metal having a low emissivity, such as copper or silver, is provided on the surface of the inner bottle or outer bottle of the thermos facing the vacuum insulation layer in order to enhance the heat retention like a stainless steel thermos. Forming a thermal insulation layer consisting of
It is necessary to reduce heat transfer by radiation.

[Problems to be solved by the invention] However, when forming a vacuum heat insulating layer of a thermos,
Vacuum heat treatment is applied to promote vacuum evacuation and degas from metals.Since titanium is a metal with a high chemical activity, copper and silver in the heat insulating layer are transferred into titanium during this vacuum heat treatment. Diffusion, alloying, the effect of small emissivity originally held by copper and silver is lost, its heat retaining effect is lost, not only can not sufficiently enhance the heat retaining performance,
There was a problem of lowering.

The present invention has been made in order to solve the above problems, and has as its object to provide a method for manufacturing a titanium thermos which is lightweight and has excellent heat retaining performance.

[Means for Solving the Problems] According to the present invention, a metal layer having an emissivity smaller than the emissivity of the inner and outer bottles is formed on at least a part of the inner and outer bottles with a thickness of 10 μm or more. And at the mouth to form a double structure, which is subjected to a vacuum heating treatment of 500 ° C. or more and 800 ° C. or less and 5 minutes or more and 60 minutes or less to leave the surface layer of the metal layer as a heat insulating layer and the lower layer Is reacted with titanium or a titanium alloy to form an alloy layer, and an exhaust port provided in one of the inner and outer bottles is sealed to form a vacuum heat insulating layer.

[Action] A metal layer having an emissivity smaller than the emissivity of the inner / outer bottle is provided on part or all of the outer surface of the inner bottle or the inner surface of the outer bottle.
After being formed with a film thickness of 10 μm or more, when subjected to a vacuum heat treatment of 500 ° C. or more and 800 ° C. or less and 5 minutes or more and 60 minutes or less, only the lower layer portion of the metal layer diffuses into titanium to form an alloy layer . On the other hand, the surface layer portion of the metal layer does not react and remains as a heat insulating layer, so that a titanium thermos exhibiting sufficient heat insulating performance can be obtained.

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

FIG. 1 is an example of a titanium thermos obtained by the manufacturing method of the present invention.

The titanium thermos has a double structure in which the inner bottle 1 is fitted into the mouth of the outer bottle 2 having a larger diameter than the inner bottle 1 and these mouths are joined to each other. A vacuum provided between the inner bottle 1 and the outer bottle 2 is evacuated to form a vacuum heat insulating layer 3.

The inner bottle 1 is a bottomed cylindrical bottle body including a reduced-diameter mouth portion, a body portion having a larger diameter than the mouth portion, and a bottom portion following the body portion, and the entire outer surface of the inner bottle 1 is provided. Is provided with an alloy layer 4 made of a titanium alloy of the inner bottle 1 and a heat insulating layer 5 made of a metal having a lower emissivity than the constituent metals of the inner bottle 1.
By forming the heat insulating layer 5 on the outer surface of the inner bottle 1 with the alloy layer 4 interposed therebetween, the emissivity of heat from the inner bottle 1 is kept small, and the heat insulating effect of the thermos is improved.

The outer bottle 2 is a bottomed cylindrical bottle body including a cylindrical outer bottle body having a diameter larger than that of the inner bottle 1 and an outer bottle bottom connected thereto. One end is reduced in diameter to form a small-diameter mouth, and this mouth is joined to the mouth of the inner bottle 1. An exhaust hole 6 is formed at the center of the bottom of the outer bottle, and the exhaust hole 6 is sealed from the outside by a sealing plate 7. Further, the gap between the inner bottle 1 and the outer bottle 2 is evacuated to form a vacuum heat-insulating layer 3 so that the thermos can keep its heat insulating performance.

In the titanium thermos having such a structure, the inner bottle 1 on which the metal layer 8 is formed as shown in FIG. After forming a double structure as shown in the figure, the space between the inner bottle 1 and the outer bottle 2 is evacuated to a vacuum heat insulating layer 3 and at a temperature of 500 ° C.
The metal layer 8 is made into the alloy layer 4 and the heat insulating layer 5 by performing a vacuum heating process at a temperature of 5 ° C. or less for 5 minutes to 60 minutes, and the exhaust holes 6 are sealed with a sealing plate 7.

First, as shown in FIG. 2, titanium or a titanium alloy is formed into a cylindrical shape with a bottom to produce an inner bottle 1, and the inner bottle 1 is placed on the outer surface of the inner bottle 1 with a lower emissivity than the constituent material of the inner bottle 1. A body having a small emissivity or a metal layer 8 made of silver, nickel, etc.
m or more.

The metal layer 8 can be formed by electroless plating or electroplating such as a silver mirror reaction. If the thickness of the metal layer 8 is less than 10 μm, all of the metal layer 8 diffuses into the inner bottle 1 and becomes the alloy layer 4 during the vacuum heating process described below, which is not preferable because the heat retention performance of the thermos bottle is reduced. The metal layer 8 may be formed directly on the outer surface of the inner bottle 1 or may be formed after forming a base layer of nickel or the like.

When such an underlayer is formed, the adhesion between the inner bottle 1 and the heat retaining layer 5 can be improved, and peeling of the heat retaining layer 5 during movement in each step or during vacuum heat treatment described later is prevented. Not only is this preferable, but also it is possible to prevent all of the metal layer 8 from diffusing into titanium and forming a titanium alloy at the time of the vacuum heat treatment, and to make it easier for the heat retaining layer 5 to remain.

Next, titanium is formed and has a diameter slightly larger than that of the inner bottle 1, the diameter of the mouth is reduced to be equal to the diameter of the mouth of the inner bottle 1, and an exhaust hole 6 is formed in the center of the bottom. A bottomed cylindrical outer bottle 3 is produced.

Then, the mouth portion of the inner bottle 1 is fitted to the mouth portion of the outer bottle 3, and these are joined by spot welding or the like to obtain a bottle having a double structure as shown in FIG.

A vacuum heating treatment is applied to the double-structured bottle thus manufactured. At the time of this vacuum heating treatment, the inside of the gap between the inner bottle 1 and the outer bottle 2 is evacuated to form a vacuum heat insulating layer 3.
By this vacuum heating treatment, the metal in the lower layer of the metal layer 8 formed on the outer surface of the inner bottle 1 diffuses into the inner bottle 1 and is converted into titanium alloy, so that the alloy layer 4 is formed. However, since the thickness of the metal layer 8 is as large as 10 μm or more,
Are not diffused into the inner bottle 1 made of titanium, and the surface portion of the metal layer 8 remains unreacted without being diffused. Since the surface layer of the remaining metal layer 8 is made of a metal having a lower emissivity than the inner bottle 1, it can be used as the heat insulating layer 5.

The heating temperature of the above vacuum heating process is 500 ° C or more and 800
C. or less, and the treatment time is preferably from 5 minutes to 60 minutes. If the heating temperature is lower than 500 ° C., the degassing for releasing the gas adsorbed on the inner bottle 1, the outer bottle 2 and the metal layer 8 cannot be performed sufficiently. All of them are diffused into the inner bottle 1 and the heat insulating layer 5 does not remain. Similarly, if the heating time is less than 5 minutes, degassing is not sufficient,
If it is longer than 60 minutes, the entire metal layer 8 becomes the alloy layer 4.

After such a vacuum heating process, the exhaust hole 6 formed at the bottom of the outer bottle 3 is sealed from the outside with the sealing material 7 by the solid brazing material 9 or the like, whereby a titanium thermos can be obtained. . As the solid brazing material 9, Ag-Cu
A brazing material having good compatibility with titanium, such as -In, Ag-CuSn, Ag-Cu, and Cu-P, can be used.

The manufacturing method of the present invention is not applied only when the titanium thermos shown in FIG. 1 is manufactured. For example, in order to form the vacuum heat insulating layer 3, the tip tube 10 is formed at the bottom of the outer bottle 2. Can be connected, and degassing can be performed through this. FIG. 4 shows an embodiment of the titanium thermos thus produced. In order to manufacture such a titanium thermos, the inner bottle 1 having the metal layer 8 formed on the outer surface is fitted into the mouth of the outer bottle 2, and then heated and heated through the tip tube 10. It can be manufactured by evacuating the gap formed between the bottle 1 and the outer bottle 2, cutting off the tip tube 10 after the degassing gas is completed, and sealing it.

Although the titanium thermos shown in FIGS. 1 and 4 both have the metal layer 8 formed on the outer surface of the inner bottle 1, the manufacturing method of the present invention is not limited to these, and the inner surface of the outer bottle 2 is not limited thereto. The metal layer 8 may be formed on both the outer surface of the inner bottle 1 and the inner surface of the outer bottle 2 or on only one of them.

Further, in each of the titanium thermos shown in FIGS. 1 and 4, the vent hole 6 is provided at the bottom of the outer bottle 2, but the position of the vent hole 6 is not limited to this. It may be provided in any one of the bottles 2.

[Effects of the Invention] As described above, in the method for manufacturing a titanium thermos of the present invention, a metal layer having an emissivity smaller than the emissivity of the inner and outer bottles is formed on at least a part of the inner and outer bottles with a film thickness of 10 µm or more. Formed, then the inner bottle and the outer bottle are joined at the mouth to form a double structure, which is subjected to a vacuum heat treatment of 500 ° C or more and 800 ° C or less and 5 minutes or more and 60 minutes or less to form a surface layer of the metal layer. Forming an alloy layer by reacting the lower layer with titanium or a titanium alloy while leaving a heat insulating layer, and forming a vacuum heat insulating layer by sealing an exhaust port provided in one of the inner and outer bottles. Therefore, it is possible to easily manufacture a lightweight titanium thermos having excellent heat insulation performance.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an example of a titanium thermos obtained by the production method of the present invention, and FIGS. 2 and 3 are schematic configuration diagrams showing one step of the production method of the present invention. FIG. 4 is a schematic configuration diagram showing another example of a titanium thermos obtained by the manufacturing method of the present invention. 1 ... inner bottle, 2 ... outer bottle, 3 ... vacuum insulation layer, 4 ... alloy layer, 5 ... heat insulation layer, 8 ... metal layer.

 ────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-1-317413 (JP, A) JP-A-1-268520 (JP, A) JP-A-64-31047 (JP, A) JP-A-58-58 124415 (JP, A)

Claims (1)

(57) [Claims] An inner bottle and an outer bottle are both made of titanium or a titanium alloy, and at least a part of the inner and outer bottles is used for manufacturing a titanium thermos in which a gap between the inner and outer bottles is a vacuum heat insulating layer. Forming a metal layer having an emissivity smaller than the emissivity of the inner and outer bottles with a thickness of 10 μm or more,
Then, the inner bottle and the outer bottle are joined at the mouth to form a double structure, which is subjected to a vacuum heating treatment of 500 ° C or more and 800 ° C or less and 5 minutes or more and 60 minutes or less, so that the surface portion of the metal layer is a heat insulating layer. The lower layer is reacted with titanium or a titanium alloy to form an alloy layer while remaining, and a vacuum heat insulating layer is formed by sealing an exhaust port provided in one of the inner and outer bottles. Manufacturing method of titanium thermos