JPH03267023A - Manufacture of metallic vacuum bottle - Google Patents

Abstract

PURPOSE:To seal a sealing port certainly without using jigs by melting wax material set on the plumb upper wall of an exhaust hole, and permitting the wax material to flow plumb downward along the wall, after a void section between internal and external bottles is set to a specified vacuum degree, and by sealing the exhaust hole. CONSTITUTION:A metallic internal bottle 1 and a metallic external bottle 4 are jointed to each other at a port section, and a void section 5 between the internal and external bottles 1, 4 is evacuated and sealed. In its case, on the bottle wall of either internal bottle 1 or external bottle 4, an evacuated small hole or slit-shaped exhaust hole 10 is set. After that, on the plumb upper wall of the exhaust hole 10, wax material 11 is set. In this state, vacuum-heating processing is performed, and the void section 5 between the internal and external bottles is set to a specified vacuum degree, and after that, the wax material 11 is melted, and is permitted to flow downward vertically along the wall, and the exhaust hole 10 is sealed. As a result, at the time of vacuum-sealing, a sealing port can certainly be sealed without using jigs, and a manufacturing process can be automatized.

Description

DETAILED DESCRIPTION OF THE INVENTION "Industrial Application Field" The present invention relates to a method for manufacturing a metal thermos flask in which the exhaust port can be vacuum-sealed without using a sealing member such as a sealing plate.

"Prior Art" FIG. 11 shows a metal thermos flask manufactured using a conventional metal thermos flask manufacturing method.

This metal thermos bottle consists of a bottomed cylindrical inner bottle 1, an outer bottle 4 consisting of a cylindrical outer bottle body 2, and an outer bottle bottom 3, and there is a gap between the inner bottle 1 and the outer bottle 4. The part 5 is evacuated and sealed to form a vacuum heat insulating layer. The outer bottle body 2 has the mouth of the inner bottle 1 hermetically joined to its four reduced diameter parts, and the outer bottle bottom at the open end opposite to the mouth of the outer bottle body 2. 3 are hermetically joined. Approximately at the center of the outer bottle bottom 3, there is a recess 6 recessed toward the inner bottle 1 side.
is formed, and furthermore, an exhaust lower is formed approximately at the center of this recess 6. A sealing plate 8 is airtightly attached to this exhaust lower.

Next, a method for manufacturing such a conventional metal thermos flask will be explained.

First, the inner bottle 1 and the outer bottle body 2, which are integrated at the mouth, are
The outer bottle is turned upside down so that the bottom 3 faces upward, and supported by a jig or the like. Next, solid brazing filler metal is placed at appropriate intervals around the circumference of the exhaust lower provided in the fourth section 16, and then the sealing plate 8 is placed on the brazing filler metal. In this state, vacuum heating treatment is performed in a vacuum heating furnace while supporting it with a jig or the like. As a result, after the inside of the cavity 5 is evacuated, the solid brazing material is melted, and the sealing plate 8 falls under its own weight, closing the exhaust lower and vacuum-sealing it. In this way, a conventional metal thermos flask is manufactured by forming the void 5 into a vacuum heat insulating layer.

``Problem to be Solved by the Invention'' However, in the conventional method for manufacturing dual metal thermos flasks, it is necessary to hold the thermos upside down in a vacuum heating furnace during evacuation. Therefore, there was a problem of the cost of preparing the above-mentioned jig in the vacuum heating furnace, and the problem that the space in the vacuum heating furnace could not be used effectively because of this jig.

In addition, in the work of arranging the brazing material around the exhaust lower and placing the sealing plate on top of it, the solid brazing material and the sealing plate 8 may be displaced from the exhaust lower, making it complicated to position them securely. in,
Moreover, these tasks are difficult to automate, so
There was also a problem in that these operations had to be performed manually and were time-consuming.

The present invention has been made in view of the above circumstances, and is a method for manufacturing a metal thermos flask, which can reliably seal the sealing opening without using a jig during vacuum sealing, and can further automate the manufacturing process. The purpose is to provide the following.

``Means for Solving the Problems'' In the present invention, an exhaust hole for vacuum exhaust is provided in the bottle wall of either the inner bottle or the outer bottle, and then a brazing material is placed on one wall vertically of the exhaust hole. In this state, a vacuum heat treatment is performed to first bring the gap between the inner and outer bottles to a predetermined degree of vacuum, and then the temperature is further increased to melt the brazing filler metal and cause it to flow vertically downward. The above problem is solved by sealing the exhaust hole.

``Operation'' After placing the brazing filler metal on the vertical sides of the exhaust hole provided in the inner bottle or outer bottle, the melted brazing filler metal is transferred into a vacuum heating furnace and subjected to vacuum heating treatment. It flows vertically downward and seals the exhaust hole.

Therefore, there is no need to invert the thermos bottle in the vacuum heating furnace, a jig for supporting it in the inverted state is not required, and it can be held in the furnace in a stable state. Furthermore, since there is no need to place a jig inside the vacuum heating furnace, the space within the vacuum heating furnace can be used effectively, and a large number of thermos flasks can be sealed in just one minute.

"Example" Hereinafter, the method for manufacturing a metal thermos flask of the present invention will be described in detail with reference to the drawings.

(Example 1) FIGS. 1 and 2 show the state before vacuum sealing in the first embodiment of the present invention (hereinafter, the thermos flask in this state will be referred to as a sealable thermos flask).

This sealable thermos includes a bottomed cylindrical metal outer bottle 4,
The outer bottle 4 is formed by joining an inner bottle l made of metal in the shape of a cylinder with a bottom at the mouth, and the outer bottle 4 has a shoulder near the end on the mouth side that gradually reduces in diameter as it goes toward the mouth. It is composed of an outer bottle body 2 consisting of a section 9a and a cylindrical body 9b, and an outer bottle bottom 3 that is hermetically joined to an opening on the opposite side of the mouth of the outer bottle body 2. be.

In such a pre-sealed thermos flask, an exhaust hole 10 is first formed in the approximate center of the shoulder portion 9a in the axial direction. Next, with the sealable thermos flask in an upright position, that is, with the mouth facing upward, the brazing material 11 is placed vertically above the exhaust hole 10. Here, it is preferable that the brazing filler metal 11 is placed not too far away from the exhaust hole IO. Also, the brazing material II is the brazing material 1
1 is adhered to the shoulder portion 9 by heating and melting a portion, and then pressing this portion onto the shoulder portion 9a and adhering it, or by adhering it with an adhesive.

The sealable thermos flask with the exhaust hole 10 formed and the brazing material 11 arranged therein is housed in a vacuum heating furnace as it is, that is, with the mouth facing upward, and vacuum heating treatment is performed.

As a result, first, the cavity 5 is evacuated through the exhaust hole 10 while being heated moderately below the melting point of the brazing filler metal, and then the upper filler filler filler metal 11 is heated to a temperature higher than the melting point of the filler filler metal 11 to melt it. It is caused to flow downward and into the exhaust hole IO.

The inflowing brazing filler metal 11 further enters the exhaust hole IO due to capillary action and seals the exhaust hole 10.

FIG. 3 shows a state in which the exhaust hole IO is sealed with the brazing material 11 in this manner.

” The diameter of the small hole of the bipedal exhaust hole 10 is 0.1 mm.
It is preferably within the range of ~2.0 mm. this is,
If the diameter of the exhaust hole IO is smaller than O, I mm, the cavity 5
If the diameter is larger than 2.0 mm, the exhaust hole IO may not be sealed due to surface tension when the brazing filler metal 11 flows down and flows into the exhaust hole 10, which is undesirable. Note that, depending on the exhaust conditions, a plurality of exhaust holes of the above-mentioned size may be provided.

Further, the brazing filler metal 11 is made by kneading a metal brazing material in a binder to form a paste, and this metallic brazing material contains N.
Metal solders with few components that vaporize in vacuum, such as N11A and Cu5AuqSnqA11TiSP, are preferred. These metal solders are used in the form of granules or powder. In addition to these metal waxes,
It is also possible to knead a metal such as stainless steel or carbon steel, which has a higher melting point than the metal solder, into the binder in the form of powder or scales. By kneading such metals, it is possible to increase the diameter of the exhaust hole 10 to be sealed, and when the diameter of the exhaust hole IO becomes larger, the drilling process when forming the exhaust hole IO becomes easier. The number of defects is small, and the evacuation process can be completed in a short time.

According to this embodiment, since the vacuum heating treatment can be performed with the mouth facing upward, a jig for supporting and storing the sealed-face thermos in an inverted state in the vacuum heating furnace, etc. is not necessary. Further, since the brazing filler metal 11 is melted in a vacuum, the gas generated in the brazing filler metal 11 during melting is also exhausted, so that no air bubbles (voids) are generated in the brazing filler metal II. Therefore, since sealing can be performed using the void-free brazing material +1, highly airtight sealing is possible.

(Example 2) Next, a second example of the present invention will be described using FIGS. 4 and 5.

FIG. 4 shows a Murakami thermos according to a second embodiment of the present invention. The difference between this Murakami thermos and that of the first embodiment is that, as shown in FIGS. 4 and 5, the shape of the exhaust hole 10 is a long slit-shaped hole extending in the circumferential direction of the shoulder 9a. It is a point. The width of this elongated hole is 0.1 to 0.0 for the same reason as described in the first embodiment above.
It is preferably within the range of 2.0 mm.

Such a sealed thermos flask is placed in a vacuum heating furnace in the same manner as in the first embodiment, and subjected to vacuum heating treatment to produce a metal thermos flask. At this time, the brazing filler metal II melts into a flowable state and flows down into the exhaust hole 10. However, in this embodiment, since the exhaust hole 10 is a long slit-like hole extending in the circumferential direction, the brazing filler metal II can be melted and flowed. 11 is the exhaust hole 10 (two inflows).

Therefore, vacuum sealing can be performed more reliably at the exhaust hole.

(Embodiment 3) FIG. 6 shows a Murakami thermos according to a third embodiment of the present invention.

The difference between this sealed thermos and the first embodiment is as follows:
An exhaust hole 10 is formed in the neck 12 of the inner bottle I. This neck portion 12 is formed by curving inward the portion facing the shoulder portion 9 of the inner bottle 1, and the exhaust hole 10 is formed in the neck portion I2.
It is formed on the upper side of the inner bottle 1, that is, on the part where the inner circumferential surface of the inner bottle 1 faces upward.

After storing such a Murakami thermos in a vacuum heating furnace with the mouth facing upward, a vacuum heating treatment is performed. In this vacuum heat treatment, the brazing filler metal 11 melts into a fluid state, moves down the inner peripheral surface of the inner bottle I in the vertical direction, flows into the exhaust hole IO, and seals the exhaust hole 11.

In this embodiment, since the exhaust hole 10 is formed in the inner bottle 1, the exhaust hole 10 sealed with the brazing material 11 is not exposed to the outside. Therefore, there is no need to perform post-processing such as smoothing the exhaust hole IO after sealing.

(Embodiment 4) 0 FIGS. 7 and 8 show a sealed thermos flask according to a fourth embodiment of the present invention.

The difference between this sealed thermos flask and the first embodiment is as follows.
A recess 1 in which an exhaust hole IO is formed in the shoulder 9a of the outer bottle body 2
It is a point formed within 3. The recess I3 has a rectangular shape with both longitudinal ends semicircular, and is formed so that its longitudinal direction extends in the circumferential direction of the outer bottle body 2. The recess 13 has a bottom curved toward the inner bottle 1, and an exhaust hole 10 is formed approximately in the center thereof. Further, the solder t, I' + 1 is disposed approximately in the longitudinal center of the recess 13, that is, vertically above the exhaust hole IO, and is bonded thereto.

After such a sealed thermos flask is housed in a vacuum heating furnace with the mouth facing upward, a vacuum heating treatment is performed. In this vacuum heat treatment, the brazing filler metal 11 melts into a fluid state, flows vertically downward around the outer periphery of the shoulder portion 9, and flows into the recess 13. The brazing filler metal 11 that has flowed into the recess 13 enters the exhaust hole II by capillary action, as shown in FIG. 9, and seals the exhaust hole 11.

In this embodiment, since the recess I3 is provided and the exhaust hole 11 is provided in the recess 13, the brazing filler metal +1 that has melted and flowed down in the vacuum heating furnace accumulates in the recess 13. Therefore, the brazing material 11 reliably enters the exhaust hole 10 and seals the exhaust hole.

(Example 5) FIG. 10 shows a sealed thermos flask in a fifth example of the present invention.

The difference between this sealed thermos flask and the first embodiment is as follows.
The exhaust hole IO is provided in the body 9b of the outer bottle body 2.

In this embodiment, first, the sealed thermos is turned over and adjusted and fixed so that the exhaust hole 10 is located in the upper half of the body 9b and not at the top. Then,
The brazing material 11 is disposed vertically above the exhaust hole 10 in the overturned state, that is, at a position moved from the exhaust hole 10 in the circumferential direction of the body portion 9b. In this state, it is carried into a vacuum heating furnace and subjected to vacuum heating treatment. In this vacuum heat treatment, the brazing filler metal 111 melts into a fluid state, flows down the outer peripheral surface of the body 9b in the circumferential direction, and vertically downward in the state of being rolled over, and flows into the exhaust hole IO. It flows in and seals the exhaust hole II.

"Effects of the Invention" As explained above, the present invention provides an exhaust hole for vacuum sealing in either the inner bottle or the outer bottle, and then places a brazing material vertically above the exhaust hole. By performing a vacuum heat treatment under the condition to evacuate the gap between the inner bottle and the outer bottle and then melting the brazing filler metal, the brazing filler metal melts and flows vertically downward, sealing the exhaust hole. Since this is a method for manufacturing a metal thermos flask, there is no need to invert the thermos bottle before sealing and perform vacuum heating treatment as in conventional manufacturing methods. Not only does it not require any jigs, but it can also be processed in an extremely stable state. Furthermore, since there is no need to place a jig inside the vacuum heating furnace, the space within the vacuum heating furnace can be used effectively, and a large number of thermos flasks can be sealed in just one minute.

2 Furthermore, since the present invention can perform vacuum sealing of the gap without using a sealing plate, it is possible to reduce the occurrence of sealing failures due to displacement of the sealing plate, etc. Furthermore, the supply of the brazing material only requires placing the brazing material vertically above the exhaust hole, making it possible to completely automate the manufacturing process. Furthermore, in the conventional sealing method, the large-diameter exhaust hole was sealed with a sealing plate, which required a large amount of wax, but in the thermos of this invention, the outer bottle or inner bottle Since the exhaust hole is provided, the exhaust hole can be efficiently and reliably sealed with the wax melted during the vacuum heat treatment. Therefore, since the amount of brazing filler metal used can be reduced, manufacturing costs can be reduced, and since the exhaust hole can be reliably sealed, defects in vacuum sealing can be prevented. .

[Brief explanation of drawings]

Figures 1 to 3 are for explaining the first embodiment of the present invention. Figure 1 is a sectional view showing the thermos bottle before sealing, and Figure 2 shows its exhaust hole and brazing material. is a top view, and FIG. 3 is a schematic sectional view showing the exhaust hole after sealing. 4 and 5 are for explaining the second embodiment of the present invention, FIG. 4 is a sectional view showing the thermos bottle before sealing, and FIG. 5 is a front view showing the exhaust hole and the brazing material. It is a diagram. FIG. 6 is a sectional view showing a thermos flask before sealing, for explaining the third embodiment of the present invention. 7 to 9 are for explaining the fourth embodiment of the present invention. FIG. 7 is a sectional view showing the thermos bottle before sealing, and FIG. 8 is a sectional view showing the four parts, the exhaust hole, and the brazing material. The side view shown in FIG. 9 is a schematic sectional view showing the recessed portion after sealing. FIG. 10 (J This is for explaining the fifth embodiment of the present invention, and is a schematic cross-sectional view showing the thermos bottle before sealing.
FIG. 1 is a schematic cross-sectional view showing a conventional metal thermos flask. ■ ・・・Inner bottle, 4 ・・・Outer bottle, 5
・Void part, IO...exhaust hole, 11 ・
Wax shrine.

Claims (1)

[Claims] In a method for manufacturing a metal thermos flask, in which a metal inner bottle and a metal outer bottle are joined at the mouth, and the gap between the inner and outer bottles is evacuated and sealed, either the inner bottle or the outer bottle is A small hole or slit-shaped exhaust hole for vacuum evacuation is provided in the wall of the bottle, then a brazing material is placed on the wall vertically above the exhaust hole, and a vacuum heat treatment is performed in this state to close the gap between the inner and outer bottles. A method for manufacturing a metal thermos flask, characterized in that after the chamber is brought to a predetermined degree of vacuum, the brazing filler metal is melted and allowed to flow vertically downward along the wall, thereby sealing the exhaust hole.