JPS6379611A - Production of metal vacuum double tank - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] "Industrial Application Field" This invention is directed to the use of gold ratio v! used as metal thermos flasks, etc.
I'm curious about the manufacturing method for JM Sora Two Rai Customer Practice, so I'd like to ask.

"Prior Art" Conventionally, metal vacuum double containers have been manufactured, for example, by the method shown below.

That is, as shown in FIGS. 6 and 7, the getter 2 is fixed to the inner wall surface of the bottomed cylindrical outer container 1 by spot welding or the like, and the outer container 1 is placed in the upright position. A linear or powdery brazing material 3 is housed inside. Next, the inner container 4 having an outer diameter smaller than the inner diameter of the outer container 1 is housed in the outer container 1 so as to be substantially coaxial with each other so that a gap is formed between the inner and outer containers.
and the open end 6 of the inner container 4 are partially temporarily fixed by spot welding or the like. Next, these outer containers! Then, the inner container 4 is turned upside down, the brazing material 3 is collected in the open end 5.6, and in this state, it is placed in a vacuum heating furnace (not shown).
600-120 under vacuum below xlo-” Torr
Heat treatment is performed at a temperature of 0° C. to melt the brazing material 3 as shown in FIG. This is a method of joining the end portion 6 and integrating it.

By the way, in order to manufacture a metal vacuum double container by this manufacturing method, a gap is formed between the open end 5 of the outer container 1 and the open end 6 of the inner container 4 so that the gap between the inner and outer containers can be evacuated. The gap size is 0.05 to 0.2n++n.
Range of degree (when using nickel solder as brazing material 3)
It is necessary to set it to .

This dimension is determined based on the balance between the efficiency of evacuation when evacuation is performed from the gap and the mechanical strength of the open end 5.6 after vacuum sealing.

``Problems to be Solved by the Invention'' However, the container configured as described above had the following problems during its manufacture. That is, [1] this container houses the inner container 4 in the outer container i, and heats it under vacuum with the opening side of the container facing down so that the brazing material 3 is placed near the joint between them. However, if the opening side is facing down, the container is unstable and tends to tilt, making it difficult to evenly distribute powdered or linear brazing material to the joint and place it properly. In addition, since it is difficult to confirm the appropriate arrangement, it is often impossible to uniformly weld the joints, and there is a problem that brazing failures such as failure to maintain a vacuum are likely to occur.

[2] In order to prevent the above brazing defects, the brazing material 3 should be
It is necessary to use a larger amount of brazing material 3 than is necessary to fill the gap between the joints, and the manufacturing cost increases due to the large amount of brazing material 3 used. If there is too much brazing material 3 at the joint, there is a problem in that the heat retaining ability of the inner container 4 decreases.

The object of the present invention is to solve the above-mentioned problems, prevent poor brazing during manufacturing, and provide a metal vacuum double container with good heat retention ability.

"Means for Solving the Problems" The present invention provides a method for manufacturing a metal vacuum double container as described above. A recess is formed in the joint surface of the container, a brazing material is interposed in the recess, and the brazing material is melted to join the open ends of the inner and outer containers by brazing. It is something.

"Function" When the inner container is housed in the outer container, the manufacturing method of the present invention interposes a brazing material in the recess formed in either the open end of the outer container or the open end of the inner container. Then, heat treatment is performed under vacuum. After the heated brazing material melts within the recess, it is welded to the inside of the recess or the vicinity thereof, thereby joining the outer container and the inner container.

At this time, brazing can be performed with the open end surfaces of the inner and outer containers facing either upward or downward.

1 to 3 are diagrams showing a first example of a metal vacuum double container manufactured by the manufacturing method of the present invention.

This metal thermos flask 7 houses a bottomed cylindrical inner container 4 inside a bottomed cylindrical outer container l. The open end 5 of the container 1 and the open end 6a of the inner container 4 are joined by brazing, and a vacuum layer 8 is formed between the outer container 1 and the inner container 4. The outer container 1 is made of carbon steel, and the inner container 4 is made of carbon steel.
It is made of stainless steel for corrosion resistance.

At the open end 6a of the inner container 4, a recess 10 is formed in an annular shape along the opening circumferential surface, which is recessed relative to the joint surface 9 of the inner and outer containers 1 and 4. As shown in FIG. 2, a brazing material 3 is welded in and near the recess 10. As shown in FIG. When the inner container 4 is housed in the outer container 1, this brazing material 3 is interposed in the four parts Iθ as shown in FIG. This is what I did.

The brazing material 3 is a string-like material that can be easily placed in the annularly formed recess 1O, and the material is made of a component with relatively high vapor pressure such as nickel solder, silver solder, copper solder, etc. Those that do not contain it are preferably used.

The method for manufacturing the metal thermos flask 7 configured as described above is as follows. First, the inner container 4 is housed in the outer container 1,
The open end 5 of the outer container 1 and the open end 6a of the inner container 4 are brought into contact. At this time, a string-shaped brazing material 3 is placed in the recess lO of the inner container 4 along the entire circumference of the annular recess 10.
intervene. Next, the opening end 5 of the outer container 1 and the opening end 6a of the inner container 4 are aligned so that a gap is formed that allows the space between the inner and outer containers 1 and 4 to be evacuated, and spot welding or the like is performed. Temporarily fasten using the method described below. In addition, as a means for positioning and temporarily fixing the inner and outer containers 1 and 4, a dowel pushing part as described in Japanese Patent Application No. 61-54287 is formed, and this dowel pushing part temporarily fixes the inner and outer containers 1 and 4. It is convenient to have a configuration that does this. Also, the thickness C of the string-shaped brazing material 3 interposed in the recess 10 is determined by the inner diameter A of the open end 5 of the outer container l and the bottom outer diameter B of the recess 10 of the open end 6a of the inner container 4. When used with a thickness that satisfies the relationship A≦B+2G, the brazing material 3 interposed in the recess 10 will not shift from the inside of the recess IO, and
Moreover, the outer container I and the inner container 4 can be fitted together through the brazing material 3 and held in a predetermined position, which is convenient.

The gap size between the inner diameter A of the outer container 1 and the outer diameter of the inner container 4 is determined by the efficiency of evacuation when vacuum is drawn from this gap and the mechanical strength between the open end 5 and Ga after vacuum sealing. This gap size is determined based on trade-offs and other factors, but since the gap size is reduced when the opening end 5.6a is heated for the brazing material, it is necessary to take this reduction into consideration when setting the gap size, and it is 0.6 mm as in the conventional case. 05-0
, about 2 ma+ is preferable. For example, a metal thermos flask 7 whose diameter of the open end 5 of the outer container l is about 40 mm is
When the degree of gap reduction was examined under the brazing temperature condition of 00°C, the difference between the inner diameter A of the outer container St and the outer diameter of the inner container 4 was 0.086 to 0°099+mn compared to that at room temperature. A reduction was observed.

Next, the metal thermos flask 7, which had been temporarily fixed with an appropriate gap between the open ends 5.6a of the inner and outer containers 1 and 4, was placed in a vacuum heating furnace (not shown) with the open side facing upward. Afterwards, under a vacuum of less than l x 10-” Torr, 600 ~
Heat treatment is performed at a temperature of 1200°C.

By this heat treatment under vacuum, the air between the inner and outer containers 1.4 is exhausted from the gap between the open ends 5.68, and the brazing material 3 interposed in the recess 10 is melted, and the inner and outer containers 1. At the same time, the gap between the open ends 5 and 6a is filled and vacuum sealed, and the open ends 5 and 6a are joined by brazing. As a result, the desired metal thermos flask 7 in which a vacuum layer is formed between the inner and outer containers 1 and 4 is obtained.

According to the above manufacturing method, the recess 1O is formed in the open end 6a of the inner container 4, and the brazing material 3 is interposed in the recess 10, so that the gap between the open ends 5 and 6 of the inner and outer containers 1 and 4 is After fixing by spot welding etc., heat treatment can be performed under vacuum even with the open side of the container facing upward, so there is no problem such as tilting the container during heat treatment and uneven welding of the brazing metal. It is possible to prevent brazing defects.

In addition, since the brazing material 3 is interposed in the recess 1O, when brazing is performed, it is possible to reliably braze with the minimum amount of brazing material 3 required, thereby reducing wastage of the brazing material 3. Since the excess brazing material 3 is not welded to the joint between the inner and outer containers 1 and 4, the heat retention ability of the inner container 4 can be improved.

FIG. 4 shows a second example of a metal vacuum double container manufactured by the manufacturing method of the present invention, and the reference numeral 7 in the figure is a metal thermos flask.

In the first example described above, when placing the brazing material in the recess lO formed in the open end 6 of the inner container 4, the annular recess 10
However, in this second example, a short string-like brazing material 3.3 is placed inside the recess.
It is constructed by arranging multiple...

In the manufacturing method according to the second example, each of the brazing fillers 3, 3, etc. melted by heat treatment under vacuum accumulates in the lower part of the recess 10, spreads around the entire circumference of the recess 10, and reaches the open ends of the inner and outer containers 1, 4. Since it is possible to perform a soldering joint between portions 5 and 68, the metal thermos 7 made by this manufacturing method has the same performance as that made by the manufacturing method of the first example above. is obtained.

The manufacturing method according to the second example provides the same effect as the manufacturing method according to the first example described above, and also creates gaps between the plurality of brazing materials 3,3, etc. interposed in the recess 1O. Inner and outer containers when heat treated under vacuum! , 4 can be efficiently exhausted.

FIG. 5 shows a third example of a metal vacuum double container manufactured by the manufacturing method of the present invention, and reference numeral 11 indicates a metal 20 thermos flask.

This 20 thermos flask 11 houses two bottomed cylindrical inner containers 4.4 from both ends of a cylindrical outer container 12 with their bottoms facing each other, and is heated under vacuum. ,
Both the upper and lower open ends 5.6a, . . . are joined by brazing. an open end 6a of each of the two inner containers 4.4;
A recess 1O110 is formed in 6a.

The method for manufacturing the above 20 thermos flasks 11 is as follows. First, two inner containers 4.4 are accommodated in the outer container l. At this time, a brazing material 3 is interposed in each of the recesses to and io. The brazing material 3 in the recess toS to may be interposed around the entire circumference along the recess lO as in the first example above, or it may be in the form of a short string as in the second example above. A plurality of them may be interposed. Next, align the outer container 11 and the inner container 4.4 to appropriate positions, and open both the upper and lower open ends 5.6a.
・Temporarily fix the gap using fixing means such as spot welding. Next, the 20 thermoses 11 that have been temporarily fixed are housed in a vacuum heating furnace with one opening side facing down, and heat treatment is performed under vacuum. This allows both the upper and lower open ends 5.
6a, . . . Obtain the target 20 thermos flasks 11 whose spaces are vacuum-sealed.

According to this manufacturing method, the soldering material can be made by heat treatment regardless of whether the opening side is facing up or down, so the above 20
Even if the shape is like a thermos flask, both the upper and lower sides can be joined by brazing in one heat treatment.

In addition, although the above-mentioned six examples were configured by forming the recess 10 in the open end 6a of the inner container 4, the recess 10 was formed in the outer container 1,
It may also be configured such that the open end 5 of it is recessed relative to the joint surface.

"Effects of the Invention" According to the manufacturing method of the present invention, a recess is formed in either the open end of the outer container or the open end of the inner container, and the recess is recessed with respect to the joint surface. Since the brazing material is interposed between the inner and outer containers, after temporarily fixing the open ends of the inner and outer containers by spot welding etc., brazing can be performed even if the open ends are heated in either direction. Therefore, it is possible to prevent brazing defects such as uneven welding of the brazing material due to tilting of the container during heat treatment.

In addition, the brazing material is interposed in the recess (therefore, when brazing is performed, it is possible to reliably braze with the minimum necessary amount of brazing material, so there is no wastage of brazing material, and the inner and outer containers are There is no need to weld excess brazing material to the joints of
The heat retention ability of the inner container can be improved.

[Brief explanation of the drawing]

1 to 3 show a first example of a metal vacuum double container manufactured by the method of manufacturing a metal vacuum double container according to the present invention, and FIG. 1 shows the metal vacuum double container after vacuum sealing. 2 is an enlarged cross-sectional view of the main parts of FIG. 1, and FIG. 3 is a side view showing the entire structure of the container.
FIG. 4 is an enlarged cross-sectional view of the main part of the figure, showing a second example of a metal vacuum double container manufactured by the method of manufacturing a metal vacuum double container of the present invention. FIG. 5 is a partially sectional perspective view of the main part of the container before sealing, and shows a third example of a metal vacuum double container manufactured by the method for manufacturing a metal vacuum double container of the present invention. FIG. 2 is a partially sectional side view showing the structure of the entire container after vacuum sealing. 6 and 7 show an example of a metal vacuum double container manufactured by a conventional method for manufacturing a metal vacuum double container, and FIG. 6 shows the entire container before vacuum sealing. FIG. 7 is a schematic sectional view showing an enlarged view of the open end of the container after vacuum sealing. 1.11...outer container, 3...brazing material, 4...
・Inner container, 5.6.6a...opening end, 7.11・
...Metal thermos flask (metal vacuum double container), 9...
・Joint surface, 10... recess.

Claims (1)

[Claims] A bottomed cylindrical metal inner container is accommodated in a metal outer container substantially coaxially with a space in between, and the open ends of the inner and outer containers are sealed with molten brazing material, and the above-mentioned In the method for manufacturing a metal vacuum double container in which a vacuum layer is formed in the inner and outer container spaces, a bonding surface of the inner and outer containers is applied to either the open end of the outer container or the open end of the inner container. A metal vacuum double container, characterized in that a recess is formed, a brazing material is interposed in the recess, and the brazing material is melted to join the open ends of the inner and outer containers by brazing. manufacturing method.