JPH02286110A - Production of vacuum bottle made of titanium - Google Patents

Abstract

PURPOSE:To easily obtain the vacuum bottle made of titanium which is light in weight and has excellent heat retaining performance by forming a metallic layer which exhibits the emissivity smaller than the emissivity of inside and outside bottles to at least a part of the inside and outside bottle and joining the inside bottle and the outside bottle in their mouth parts to form double structures, then subjecting the bottles to a vacuum heating treatment. CONSTITUTION:The inside bottle 1 is first produced by molding titanium or titanium alloy to a blind cylindrical shape and the metallic layer 8 consisting of the copper or silver, nickel or the like exhibiting the emissivity smaller than the emissivity of the constituting material of the inside bottle 1 is formed at >=10mum film thickness on the outside surface of the above- mentioned bottle. The titanium is then molded to produce the outside bottle 2 of the blind cylindrical shape which has the diameter slightly larger than the diameter of the inside bottle 1, is diametrally reduced in the mouth part to have the diameter equal to the diameter in the mouth part of the inside bottle 1 and is formed with a discharge hole 6 in the central part of the bottom. The mouth part of the inside bottle 1 is fitted to the mouth part of the outside bottle 2 produced in such a manner and the two bottles are joined by spot-welding or the like to form the bottle body of the double structures; thereafter, the bottle body is subjected to the vacuum heating treatment. The inside of the gap part between the inside bottle 1 and the outside bottle 2 is evacuated to a vacuum heat insulating layer 3. The heating temp. of the vacuum heating treatment is >=500 deg.C and <=800 deg.C and the treating time is adequately >=5 minutes and <=60 minutes.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a method for manufacturing a titanium thermos flask that is lightweight and has excellent heat retention performance.

[Prior Art] Various metal thermos flasks made of stainless steel, which has high strength and good heat retention performance, have been proposed and put into practical use. This product has excellent heat retention performance and does not cause any loss, but it has the disadvantage of being heavy and inconvenient to carry. Stainless steel also has insufficient corrosion resistance and may corrode when containing food or drinks containing salt.

For these reasons, titanium or titanium alloys (hereinafter collectively referred to as single-I titanium) are lightweight, high-strength, and highly corrosion-resistant.

) has been proposed.

In such titanium thermos flasks, in order to improve heat retention like stainless steel thermos flasks, a metal with a low emissivity, such as copper or silver, is added to the surface of the inner or outer bottle facing the vacuum insulation layer. It is necessary to form a heat insulating layer consisting of the following to reduce heat transfer due to radiation.

[Problem to be solved by the invention 1 However, when forming the vacuum insulation layer of a thermos flask, vacuum heat treatment is performed to promote vacuum evacuation and degas from the metal, but titanium is a metal with high chemical activity. Therefore,
During this vacuum heat treatment, the copper and silver in the heat insulating layer diffuse into the titanium and become alloyed, losing the low emissivity effect that steel and silver originally have, and the heat insulating effect disappears. There was a problem that not only could the performance not be sufficiently improved, but it would also be degraded.

This invention was made to solve the above problems, and an object thereof is to provide a method for manufacturing a titanium thermos flask that is lightweight and has excellent heat retention performance.

[Means for Solving the Problems] This invention forms a metal layer having a thickness of 10 μm or more and having an emissivity smaller than that of the inner and outer bottles on at least part of the inner and outer bottles, and then separates the inner and outer bottles from each other. are joined at the mouth to form a double structure, and then heated at a temperature of 500°C to 800°C for 5 minutes to 6 minutes.
A vacuum heat treatment is performed for 0 minutes or less to leave the surface layer of the metal layer as a heat insulating layer while avoiding the reaction of the lower layer with titanium or titanium alloy to form an alloy layer, and the metal layer is provided on either the inner or outer bottle. The solution was to seal the exhaust port and form a vacuum insulation layer.

"Action" Part or all of the outer surface of the inner bottle or the inner surface of the outer bottle,
10 metal layers exhibiting a lower emissivity than the emissivity of the inner and outer bottles.
After forming a film with a thickness of μm or more, the temperature is 500°C or more and 800°C.
Thereafter, when a vacuum heat treatment is performed for 5 minutes or more and 60 minutes or less, only the lower layer of the metal layer is diffused into titanium to form an alloy layer. On the other hand, since the surface layer of the metal layer remains as a heat retaining layer without reacting, a titanium thermos flask exhibiting sufficient heat retaining performance can be obtained.

[Example] Below 1. This invention will be explained in detail.

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

This titanium thermos flask has a double structure in which the inner bottle 1 is fitted into the mouth of an outer bottle 2, which has a larger diameter than the inner bottle 1, and these mouths are joined to each other. A vacuum insulation layer 3 is formed by evacuating a gap provided between an inner bottle I and an outer bottle 2.

The inner bottle 1 is a cylindrical body with a bottom, consisting of a reduced diameter mouth, a body with a larger diameter than the mouth, and a bottom that continues to the body. The alloy layer 4 made of titanium alloy of the inner bottle 1 and the inner bottle! A heat insulating layer 5 made of a metal having a lower emissivity than the constituent metals is successively provided. By forming the heat insulating layer 5 on the outer surface of the inner bottle I via the alloy layer 4, the inner bottle! This keeps the emissivity of the heat from the thermos bottle low and improves the heat retention effect of the thermos flask.

The outer bottle 2 is a bottomed cylindrical body consisting of a cylindrical outer bottle body having a larger diameter than the inner bottle 1 and an outer bottle bottom connected to the outer bottle body, and one end of the outer bottle body. is reduced in diameter to form a small-diameter mouth, and this mouth is joined to the mouth of the inner bottle I. Further, an exhaust hole 6 is formed in the center of the bottom of the outer bottle, and this 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, which maintains the heat retention performance of the thermos flask.

In the titanium thermos flask having such a structure, as shown in FIG. After creating a double structure as shown in the figure, the inside of the gap between the inner bottle II and the outer bottle 2 is evacuated to form a vacuum insulation layer 3, and the temperature
The metal layer 8 is made into the alloy layer 4 and the heat insulation layer 5 by vacuum heat treatment at 00°C or less for 5 minutes or more and 60 minutes or less, and then the exhaust hole 6 is formed.
It is manufactured by sealing with a sealing plate 7.

First, as shown in Fig. 2, the inner bottle I is made by molding titanium or titanium alloy into a cylinder shape with a bottom. A metal layer 8 made of copper, silver, nickel, etc. exhibiting a small emissivity is
Formed with a film thickness of 1 or more.

This metal layer 8 can be formed by electroless plating such as silver mirror reaction, electroplating, or the like. When the film thickness of the metal layer 8 is less than 10 μm, metal! ! ! All of 8 diffuses into the inner bottle 1 and forms the alloy layer 4, which is undesirable because it reduces the heat retention performance of the thermos flask. This 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 such as nickel.

By forming such a base layer, it is possible to improve the adhesion between the inner bottle I and the heat-retaining layer 5, and during movement in each process,
Not only is it possible to prevent the heat insulating layer 5 from peeling off during the vacuum heat treatment described later, but it also prevents all of the metal layer 8 from diffusing into titanium and becoming a titanium alloy during the vacuum heat treatment. It is also possible to make it easier for the heat retaining layer 5 to remain.

Next, titanium is molded to have a slightly larger diameter at the top of the inner bottle 1, and the diameter is reduced so that the opening is equal to the diameter of the opening of the inner bottle 1, and an exhaust hole 6 is formed in the center of the bottom. A cylindrical outer bottle 3 with a bottom is prepared.

Then, fit the mouth of the inner bottle 1 into the mouth of the outer bottle 3,
These are joined by spot welding or the like to form a double-structured structure as shown in FIG.

The double-walled bottle thus produced is subjected to vacuum heat treatment. During this vacuum heat treatment, the space between the inner bottle 1 and the outer bottle 2 is evacuated to form a vacuum heat insulating layer 3. By this vacuum heat 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 I and becomes a titanium alloy, so that an alloy layer 4 is formed. However, metal layer 8
Since the film thickness of the metal layer 8 is as thick as 10μ square or more, the metal layer 8
Not all of it diffuses into the titanium inner bottle 1, and the surface layer of the metal layer 8 remains unreacted without being diffused. Since the surface layer portion of the remaining metal layer 8 is made of a metal having a lower emissivity than that of the inner bottle 1, it can be used as the heat insulating layer 5.

The heating temperature of the vacuum heat treatment as mentioned above is 500℃ or higher8
The temperature is preferably 00° C. or lower, and the treatment time is preferably 5 minutes or more and 60 minutes or less. If the heating temperature is less than 500°C, the inner bottle 11
If degassing to release the gas adsorbed in the outer bottle 2 and metal layer 8 cannot be performed sufficiently, and if heated at a temperature higher than 800°C, all of the metal layer 8 will diffuse into the inner bottle l, causing the heat insulating layer 5 will not remain, so both are unfavorable. Likewise, if the heating time is less than 5 minutes, degassing will not be sufficient, and if it is longer than 60 minutes, all of the metal layer 8 will be removed from the alloy layer 4.
It becomes.

After such vacuum heat treatment, a titanium thermos flask can be obtained by sealing the exhaust hole 6 formed at the bottom of the outer bottle 3 from the outside with a sealing material 7 using a solid brazing filler metal 9 or the like. . This solid brazing filler metal 9 is Ag-C
u-In series, Ag-Cu5n series, Ag-Cu series, Cu-
A brazing material having good compatibility with titanium, such as P-based brazing material, can be used.

Furthermore, the manufacturing method of the present invention is not only applicable to manufacturing the titanium thermos flask shown in FIG. It is also possible to connect and degas through this. FIG. 4 shows an example of a titanium thermos flask manufactured in this manner. To manufacture such a titanium thermos flask, after fitting the inner bottle 1, which has a metal layer 8 on its outer surface, into the mouth of the outer bottle 2, 1, while heating these, 6, the chip tube! The empty S part formed between the inner bottle 1 and the final bottle 2 is evacuated through O, and after the desorption gas is finished, the tip tube lO is
It can be manufactured by press-cutting and sealing it.

In both the titanium thermos bottles shown in FIGS. 1 and 4, the metal layer 8 is formed on the outer surface of the inner bottle I, but the manufacturing method of the present invention is not limited to this, and the inner surface of the outer bottle 2 is 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 only on a part of either one.

Furthermore, although the titanium thermos flasks shown in FIGS. 1 and 4 both have an exhaust hole 6 at the bottom of the outer bottle 2, the position of the exhaust hole 6 is not limited to this, and bottle 2
It may be provided on either one of the two.

[Effects of the Invention] As explained above, the method for manufacturing a titanium thermos flask of the present invention includes forming a metal layer having a thickness of 10 μm or more on at least part of the inner and outer bottles, the metal layer having an emissivity smaller than that of the inner and outer bottles. Then, the inner bottle and outer bottle are joined at the mouth to form a double structure, and this is subjected to vacuum heat treatment at 500°C or more and 800°C or less for 5 minutes or more and 60 minutes or less to remove the surface layer of the metal layer. The lower layer is reacted with titanium or titanium alloy while remaining as a heat insulating layer to form an alloy layer, and the exhaust port provided on either the inner or outer bottle is sealed to form a vacuum insulation layer. Therefore, it is possible to easily manufacture a titanium thermos flask that is lightweight and has excellent heat retention performance.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing an example of a titanium thermos obtained by the manufacturing method of the present invention, and FIGS. 2 and 3 are both schematic configuration diagrams showing one step of the manufacturing method of the present invention. FIG. 4 is a schematic diagram showing another example of a titanium thermos obtained by the manufacturing method of the present invention. l...Inner bottle, 2...Outer bottle, 3...Vacuum insulation layer, 4...Alloy layer, 5...Heat insulation layer, 8...Metal layer.

Claims (1)

[Claims] When manufacturing a titanium thermos flask in which both the inner bottle and the outer bottle are made of titanium or a titanium alloy, and the gap between the inner and outer bottles is a vacuum insulation layer, at least a portion of the inner and outer bottles is made of radiation. A metal layer with a thickness of 10 μm or more is formed, and the inner bottle and outer bottle are then joined at the mouth to form a double structure, and this is heated at 500°C or more for 800°C or more.
A vacuum heat treatment is performed at 00°C or lower for 5 minutes or more and 60 minutes or less to leave the surface layer of the metal layer as a heat insulating layer while reacting the lower layer with titanium or titanium alloy to form an alloy layer. A method for manufacturing a titanium thermos flask, which comprises sealing an exhaust port provided on either side of the bottle to form a vacuum insulation layer.