JPH0852080A - Exhaust structure of metal vacuum insulation container - Google Patents

Abstract

(57) [Abstract] [Purpose] To enable reliable vacuum sealing at low temperature without using a sealing member such as a sealing plate. [Structure] An inner container 1A made of a metal having a bottomed structure and an outer container 1B made of a metal having a non-bottomed structure with an open bottom are formed into a double structure with a gap, and a bottom plate is provided at the bottom opening of the outer container 1B. In a metal vacuum heat insulation container in which 6 are fitted to form a heat insulation container, a taper surface 8 (2) is provided at a predetermined position of the bottom plate 6 with the heat insulation container being in an inverted posture and having a downward slope from top to bottom.
3) is formed, and the exhaust port 30 is sealed at the midpoint of the taper surface 8 (23) by the molten sealing material 13 flowing down.
Is provided to enable easy and reliable vacuum sealing in a low temperature state without using a sealing member such as a sealing plate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust structure for a metal vacuum heat insulation container such as a stainless bottle.

[0002]

2. Description of the Related Art For example, as a vacuum heat insulating container such as a metal thermos bottle, a metal inner bottle and an outer bottle are joined at a mouth portion to form a double structure, and a space between these inner and outer bottles is vacuum-sealed. Are generally known.

First, FIG. 9 shows the entire structure of the same heat insulating container 1 before vacuum sealing. The heat insulating container 1 has an inner container 1A and an outer container 1B made of metal such as stainless steel, for example, on the mouth 2 side. Are joined to each other to form a double structure, and the space 3 formed between them is evacuated and then vacuum-sealed to realize a heat insulating structure.

The inner container 1A has a bottomed bottle shape as shown in the figure, and is supported by the outer container 1B on the side of the mouth 2. Further, the outer container 1B is formed into a bottomed tubular body in which a bottom plate 60 is integrally fitted (inner fitted) in the opening edge portion 50 on the side of the bottom portion 4 whose diameter is reduced by a predetermined dimension.

The bottom plate 60 has a peripheral edge portion 60a bent into a hook shape, and has a ring-shaped groove portion left between the central portion and the outer edge portion 6a, and is bulged outward in a cylindrical shape.

Then, on the bottom surface of the bulging portion of the bottom plate 60,
As shown, a large-diameter recess 60b is formed on the inner side in the axial direction by a predetermined depth. A large-diameter exhaust port 60c is formed on the inner bottom surface of the recess 60b.

When vacuum-sealing, first, the inner container 1A and the outer container 1B are evacuated in the vacuum chamber 3 and then the container is inverted with respect to the exhaust port 60c as shown in the drawing. The sealing plate 61 is placed between the exhaust port opening edge portion and the solid brazing filler metal, and then heated at a temperature equal to or higher than the melting point of the brazing filler metal to melt the brazing filler metal, thereby sealing the sealing plate. 61 and the bottom plate 60 are integrally bonded and vacuum-sealed (for example, JP-A-3-267023).
11 of Japanese Patent Publication No. 5 or No. 5 of Japanese Utility Model Laid-Open No. 4-7026
(See figures etc.)

[0008]

However, in the case of such a conventional exhaust structure, since the diameter of the exhaust port 60c can be made sufficiently large, the total conductance at the time of exhaust can be made sufficiently high. Another problem is that the sealing plate 61 is required separately. Further, it is difficult to position the sealing plate 61 with respect to the exhaust port 60c and uniformly dispose the solid brazing material on the opening edge portion of the exhaust port 60c.
Since the diameter of 0c is large and the fusion area is wide, and it is difficult to secure the fusion accuracy by the brazing material, there is a problem in the reliability of the sealing precision.

Therefore, for example, as shown in FIG. 10, the bulging portion of the bottom plate 60 is a flat surface 60d, and a recess 64 having a small diameter is provided at the center thereof, and the molten brazing filler metal 13 for sealing is provided at the center of the recess 64. The exhaust port 63 having a small diameter that can be retained by the surface tension is formed, and the paste-like brazing filler metal 13 is injected into the recess 64 and then melted to surely seal the exhaust port 63. An exhaust structure has also been proposed (see, for example, JP-A-3-66332).

However, in the case of this construction, after evacuation, the paste-like brazing filler metal 13 is fairly accurately formed in the small-diameter recess 64.
If not injected, there is a problem that the molten brazing material is not filled in the exhaust port 63 having a small diameter, and there is a drawback that automation is difficult.

[0011]

The present invention has been made for the purpose of solving the above-mentioned conventional problems, and is constituted by the following means for solving problems.

That is, first, the metal vacuum heat insulation container according to the present invention has a double structure in which a metal inner container having a bottomed structure and a metal outer container having a non-bottomed structure with a bottom opening are provided with a space therebetween. And, in a metal vacuum heat insulation container configured by fitting a bottom plate to the bottom opening of the outer container to form a heat insulation container, in the inverted position of the heat insulation container at a predetermined position of the bottom plate, descending from above to below. A tapered surface having a gradient is formed, and an exhaust port which is sealed by the molten sealing material flowing down is provided at an intermediate position of the tapered surface.

The metal vacuum heat insulation container of the present invention is
A mooring portion of the melt sealing material is provided in the middle of the tapered surface in the above structure.

Further, in this case, the mooring portion is further formed by a cut-and-raised piece forming the exhaust port itself.

[0015]

That is, in the exhaust structure of the metal vacuum heat insulation container of the present invention, as described above, the heat insulation container is placed in an inverted posture at a predetermined position of the bottom plate which is fitted into the bottom opening of the outer container to form the heat insulation container. Since there is a tapered surface having a downward slope from the upper side to the lower side, the exhaust port is formed in the middle of the tapered surface, at a position where the tapered surface is continuous and the molten sealing material reaches reliably. The melt sealing material, such as a paste-like brazing material, placed on the upper part of the tapered surface of the downward slope is surely guided to the exhaust port by the tapered surface and filled therein.

In this case, if a mooring portion for the melt sealing material such as a cut-and-raised piece is provided in the middle of the tapered surface, the melt sealing material just flowing down is collected at the exhaust port. Since it is locked and retained, the hole is sealed more reliably.

In that case, if the exhaust port itself is formed by cutting and raising a part of the tapered surface portion, and the mooring portion is formed by a cut and raised piece generated by the cut and raised, Since the formation of the exhaust port and the formation of the mooring portion can be realized at the same time, wasteful processing is eliminated, which is convenient.

[0018]

Therefore, according to the exhaust structure of the metallic vacuum heat insulating container of the present invention, it is possible to easily and surely form a tapered surface and an exhaust port at a predetermined position of the bottom plate to easily and reliably reduce the temperature of a glass sealing material or the like. It is possible to adopt a vacuum sealing method using a melting point type brazing material and facilitate automation.

Further, since the brazing material is surely guided to the exhaust port by the tapered surface and is retained at the mooring portion, a reliable sealing work can be realized.

Further, as a result, the vacuum sealing work can be performed at a lower temperature as compared with the conventional vacuum brazing method which requires a high temperature work, and the degree of reduction in tensile strength of the container base material is small, which is possible. Therefore, the thickness of the container base material can be made thin, and the weight and cost of the product can be reduced.

[0021]

【Example】

(1) First Embodiment FIGS. 1 to 3 show an exhaust structure of a metal vacuum heat insulating container according to a first embodiment of the present invention.

First, FIG. 1 shows the overall structure of the same heat-retaining container 1 in an inverted state before vacuum-sealing. The heat-retaining container 1 comprises an inner container 1A and an outer container 1B made of metal such as stainless steel. The parts 2 are joined to each other to form a double structure, and the voids 3 formed between them are vacuum-sealed to realize a heat insulating structure.

The inner container 1A has a bottomed bottle shape as shown in the figure, and is supported by the outer container 1B on the side of the mouth 2. Further, in the outer container 1B, the bottom plate 6 is integrally fitted in the opening edge portion 5 on the side of the bottom portion 4 whose diameter is reduced by a predetermined dimension.
It is formed into a bottomed tubular body (fitted in).

As shown in detail in FIGS. 2 and 3, the bottom plate 6 has its peripheral portion 6a bent in a hook shape and has a ring-shaped groove portion 7 left at the center between the peripheral portion 6a and the outer edge portion 6a. By bulging outward in an inverted trapezoidal shape, the bulging portion 6b
The outer peripheral surface 8 is formed into a taper surface that gradually inclines from the upper side to the lower side in the inverted state in the drawing.

On one side of the bottom surface 8 of the bulging portion 6b of the bottom plate 6, a chevron groove 21 is formed which is recessed to the axial mouth portion 2 side by a predetermined depth as shown in the drawing. The groove 2
Like one taper surface of the outer peripheral surface 8 of the bulging portion 6b, a taper groove 23 that gradually descends from the upper side to the lower side in the container inverted state of FIG. A rectangular exhaust port 30 formed of a cutout hole formed by the side cut-and-raised piece 22 is provided. The exhaust port 3
0 communicates with the inside of the space 3 between the inner container 1A and the outer container 1B.

As shown in FIG. 2, the metal vacuum heat insulating container 1 before vacuum sealing having the above-mentioned structure is located above the taper groove 23 and is in the form of a fluid (paste) for vacuum sealing. For example, the brazing filler metal 13 is dropped by a predetermined set amount by, for example, a metering injection device.

The metal vacuum heat insulation container 1 to which the brazing material 13 has been dropped is further transferred into a vacuum furnace and the brazing material 1 is
After being degassed (baking step) at a predetermined temperature lower than the melting point of No. 3, it is heated at a temperature higher than the melting point of the brazing material 13 (sealing step). As a result, the brazing material 13 melts and flows downward, reaches the exhaust port 30 while being guided by the taper groove 23, and is retained by the cut-and-raised piece 22. It will be surely filled and sealed.

That is, in the exhaust structure of the metallic vacuum heat insulating container of this embodiment, the chevron groove 21 is provided at an appropriate position of the bulging portion 6b at the center of the bottom plate 6, and one side surface thereof is utilized to implement the first embodiment. The same tapered groove 23 as the example is formed, and the exhaust port 30 and the exhaust port 30 are formed in the middle of the tapered surface of the tapered groove 23.
Forming a cut-and-raised piece 22 (a mooring portion) for surely receiving the molten brazing material 13 flowing down to the portion and locking and retaining it;
The taper groove 23 ensures that the molten brazing material 13 is exhausted through the exhaust port 3
It is guided to 0 and is stopped and moored at the same position by the cut-and-raised pieces 22 with good yield. Therefore, it is possible to easily and surely adopt the vacuum sealing method using the brazing material by simply forming the taper groove 23 by utilizing the groove portion 21 and the inclined surface of the groove portion 21 on the bottom surface of the bulging portion 6b of the bottom portion of the outer container. And automation is easy.

As a result, compared with the conventional vacuum brazing method, the vacuum sealing work can be performed at a lower temperature, the degree of lowering the tensile strength of the container base material is small, and the container base material is reduced as much as possible. The thickness of the product can be reduced, and the weight of the product and the cost can be reduced.

(2) Second Embodiment The cut-and-raised piece 22 in the first embodiment may be a cut-and-raised piece 25 which is cut and raised inside as shown in FIG. 4 as the second embodiment. Even in this way, the taper groove 2
The molten brazing material 13 flowing down 3 is sufficiently locked and retained at the exhaust port 30 portion, and a highly reliable sealing action similar to that of the second embodiment can be achieved.

(3) Third Embodiment Further, as shown in FIG. 5 as the third embodiment, the taper groove 23 in the second embodiment has a flat step surface in the middle of its inclined bottom surface portion 23b. Forming 23c,
It is also possible to provide the exhaust port 31 and the cut-and-raised piece 22 on the step surface 23c.

With this structure, the brazing filler metal 13 that has been heated and melted in the sealing step can be more reliably locked and retained in the exhaust port 31, and the sealing precision can be the same as that of the first and the first. It is further improved as compared with the second embodiment.

(4) Fourth Embodiment Next, FIGS. 6 to 8 show the construction of the exhaust port portion in the exhaust structure of the metal vacuum heat insulation container according to the fourth embodiment of the present invention.

As described above, when the glass-based sealing material having a low melting point is used as the brazing material for vacuum sealing, the sealing work can be performed at a low temperature and the tensile strength of the container base material is not lowered. Complete. Therefore, there is an advantage that the thickness of the container base material can be made as thin as possible.

However, if the glass sealing material 13 is used to seal the exhaust port 70 of the exhaust port forming portion of the bottom plate 60 as shown in FIG. 11 and FIG. The diameter (hole diameter) of must be reduced to the specified diameter,
At the time of melting, the mouth retention effect due to the surface tension as shown in FIG. 12 is not secured.

On the other hand, however, if the diameter of the exhaust port 70 is made too small, there is a drawback that the total conductance during exhaust is reduced and the exhaust efficiency is deteriorated.

Therefore, in this embodiment, as shown in FIG. 6, for example, by forming the exhaust port portion 40 in a lattice shape, the overall diameter (opening area) is sufficiently enlarged, while the substantial exhaust gas is exhausted. Interstitial hole parts 40a, 40a
··· is so small that the glass sealing material 13 can be retained by the surface tension so that the total conductance at the time of exhaust can be sufficiently ensured and reliable sealing accuracy can be obtained. is there.

As a result, the molten glass sealing material 13
Are initially retained as small spherical bodies 13a, 13a ... At the interstitial holes 40a, 40a as shown in FIG. 7, but eventually they will eventually become one lump 13 as shown in FIG. Then, the entire exhaust port 40 is sealed.

The structure of the exhaust port 40 can be similarly applied to the exhaust ports 30 and 31 of the first to third embodiments if necessary.

The brazing filler metal 13 in each of the first, second and third embodiments described above is preferably a low melting point type which is melted at a low heating temperature of 500 ° C. or less as much as possible. In the vacuum brazing method using a Ni-based brazing material that has been used conventionally, the melting point of the brazing material itself is high, and in any case, high temperature brazing must be performed.

However, when high temperature brazing is performed, there is a merit of absorbing the molding strain due to annealing, but on the other hand, there is a problem that the tensile strength of the base material itself is lowered.

Therefore, in order to solve the problem, it is preferable to adopt a low melting point type glass sealing material such as a glass hang after improving the molding accuracy. As an example, (a) B ₂ O ₃ -PBO type (softening point 350 to
470 ° C.) or (b) P ₂ O ₅ —Al ₂ O ₃ —R ₂ O type (softening point 464 ° C.) type soda lead glass type one can be adopted.

As a getter material in this case, for example, a combination of (a) Zr-Ni-Nb type and (b) Zr-V-Fe type are conceivable.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an overall configuration of a metal vacuum heat insulation container according to a first embodiment of the present invention in an exhaust structure of an exhaust structure in an inverted container.

FIG. 2 is an enlarged cross-sectional view of the relevant part.

FIG. 3 is an enlarged plan view of the main part.

FIG. 4 is an enlarged cross-sectional view of a main part of an exhaust structure of a metal vacuum heat insulation container according to a second embodiment of the present invention.

FIG. 5 is an enlarged cross-sectional view of a main part showing an exhaust structure of a metal vacuum heat insulation container according to a third embodiment of the present invention.

FIG. 6 is an enlarged plan view showing a structure of an exhaust port of an exhaust structure for a metal vacuum heat insulation container according to a fourth embodiment of the present invention.

FIG. 7 is a sectional view of the exhaust port portion in a first state.

FIG. 8 is a cross-sectional view of the exhaust port portion in a second state.

FIG. 9 is a cross-sectional view showing an exhaust structure of a metal vacuum heat insulation container according to a first conventional example.

FIG. 10 is a cross-sectional view showing an exhaust structure of a metal vacuum heat insulation container according to a second conventional example.

FIG. 11 is an enlarged plan view showing a configuration of an exhaust port portion of an exhaust structure of a metal vacuum heat insulation container according to a third conventional example.

FIG. 12 is a cross-sectional view of the exhaust port portion.

[Explanation of symbols]

1 is a metal vacuum heat insulation container, 2 is a mouth part, 3 is a void, 4 is a bottom part, 6 is a bottom plate, 7 is a groove part, 8 is an outer peripheral surface, 22 and 25 are cut and raised pieces, 23 is a tapered groove, 30, Reference numeral 31 is an exhaust port.

Claims (3)

[Claims] 1. A metal-made inner container having a bottomed structure and a metal outer container having a non-bottomed structure having a bottom opening are made into a double structure with a gap therebetween, and a bottom plate is provided at the bottom opening of the outer container. In a metal vacuum heat insulation container configured by fitting to form a heat insulation container, a taper surface is formed at a predetermined position of the bottom plate in an inverted posture of the heat insulation container with a downward slope from above to below. An exhaust structure for a metal vacuum heat insulation container, characterized in that an exhaust port sealed by the melt sealing material flowing down is provided at an intermediate position. 2. The exhaust structure for a metal vacuum heat insulation container according to claim 1, wherein a mooring portion of the melt sealing material is provided in the middle of the tapered surface. 3. The exhaust structure for a metal vacuum heat insulating container according to claim 2, wherein the mooring portion is formed by a cut-and-raised piece that forms an exhaust port.