JP2738299B2 - Vacuum sealed structure of metal vacuum container - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art For example, as a vacuum insulation container such as a metal thermos such as a stainless steel bottle, a metal inner bottle and an outer bottle are joined at a mouth to form a double structure, and a gap between the inner and outer metal bottles is formed. What is vacuum-sealed is generally known.

[0003] First, Fig. 12 shows the whole structure of the vacuum heat retaining container 1 before vacuum sealing. The vacuum heat retaining container 1 has an inner container 1A made of a metal such as stainless steel and an outer container 1B having a mouth portion. The two sides are joined to each other to form a double structure, and the heat insulating structure is realized by vacuum-sealing after evacuating the gap 3 formed therebetween.

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

The bottom plate 60 is formed by bending a peripheral edge portion 60a into a hook shape and bulging outward in a cylindrical shape with a ring-shaped groove portion being left between the central portion and the peripheral edge portion 60a.

Then, on the bottom surface of the bulging portion of the bottom plate 60,
As shown in the figure, a large-diameter concave portion 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 concave portion 60b.

At the time of vacuum sealing, first, the inner container 1A and the inner cavity 3 of the outer container 1B are evacuated in a vacuum chamber, and then the exhaust port 60c is inserted into the illustrated container in an inverted state as shown in the drawing. A sealing plate 61 is placed between the opening edge of the exhaust port 60c via a brazing material, and then heated at a temperature equal to or higher than the melting point of the brazing material, thereby melting the brazing material to form A structure in which the sealing plate 61 and the bottom plate 60 are joined and integrated to perform vacuum sealing (for example,
FIG. 11 of JP-A-267023 or Japanese Utility Model Application Laid-Open No. 4-7026.
No. 5, FIG.

In the case of such a conventional exhaust structure, the diameter of the exhaust port 60c can be made sufficiently large, so that the total conductance at the time of exhaust can be increased. There are issues that need to be addressed. Further, in addition to the difficulty in positioning the sealing plate 61 with respect to the exhaust port 60c and uniformly disposing the brazing material at the opening edge of the exhaust port 60c, the brazing material is used only because the exhaust port 60c itself has a large diameter and a large fusion area. Since it is difficult to secure the fusion accuracy, there is also a problem in the reliability of the sealing accuracy.

Therefore, as shown in FIGS. 13 and 14 to 16, for example, the bulging portion of the bottom plate 60 is a flat surface 60d,
An arc-shaped concave portion 64 or a funnel-shaped concave portion 65 having an extremely small diameter such that the molten brazing material 43 can be stopped by the surface tension at the time of sealing is provided at the center thereof, and exhaust ports 63 are formed at the bottom thereof. After the paste brazing material 43 is placed on the upper opening edge of the exhaust port 63, the paste brazing material 43 is introduced into the exhaust chamber to melt the brazing material 43, so that the exhaust port 63 is melted.
(See FIGS. 1 to 3 of JP-A-3-66332 and FIGS. 1 to 3 of JP-A-4-7026) and, for example, FIGS. 19,
As shown in FIGS.
The bulging portion is a flat surface 65d, and a relatively large-diameter hemispherical concave portion 66 or a long groove 67 whose bottom is inclined is provided at the center portion thereof. An exhaust port 63 having such a small diameter that the molten brazing material 43 can be stopped by the surface tension at the time of sealing is formed at the position, and the solder on the paste is formed on the peripheral portion of the semispherical recess 66 or the other end of the long groove 67. After placing the material 43, the material is introduced into the exhaust chamber and melted, and the molten brazing material is guided to the exhaust port 63 portion using the round surface or the inclined surface to securely seal the exhaust port 63. Also, an exhausting structure has been proposed (see, for example, FIGS. 1 to 3 and FIGS. 4 to 5 of JP-A-3-119342).

According to such a configuration, the recess 66
In addition, by accurately disposing the brazing material 43 in the long groove 67, reliable vacuum sealing can be realized.

[0011]

However, since the above-mentioned metal vacuum insulation container is generally made of stainless steel, a passivation film exists on the surface thereof. The passivation film disappears in a high temperature state,
It does not disappear under the molten state of the low melting point brazing material of about 00 ° C to 600 ° C.

For this purpose, in particular, Al, Sn, N
When a metal-based brazing material having a low melting point such as i-type is used, wettability between the brazing material and the exhaust port surface is poor, and the joining strength of the brazing material at the exhaust port is low. For this reason, there is a possibility that the vacuum sealing function is impaired by, for example, an impact at the time of dropping.

On the other hand, when a glass-based low-melting-point brazing material such as lead borosilicate glass is used as the brazing material, the presence of a passive film, which is a kind of the above-mentioned oxide film, is advantageous because of the oxidative bond. However, even in this case, it is desired to improve the joining force between the brazing material and the joining surface as much as possible.

The present invention has been made in view of such circumstances, and by improving the wettability of the exhaust port surface with the low melting point brazing material and by increasing the bonding force, the exhaust port section is improved. The joint strength of the brazing material on the surface
It is an object of the present invention to provide a highly reliable vacuum sealing structure for a metal vacuum container.

[0015]

SUMMARY OF THE INVENTION The present invention has been made for the purpose of solving the above-mentioned conventional problems, and comprises the following means for solving the problems.

That is, the vacuum sealing structure of the metal vacuum container of the present invention has a double structure of a metal inner container and an outer container, and is melt-sealed at a predetermined position of the outer container by a melt sealing material. In a metal vacuum insulation container provided with an exhaust port, a concave-convex processed surface forming a joining surface with a molten sealing material is formed at an edge of the exhaust port.

The uneven surface in the structure is formed by, for example, a sandblast layer realized by spraying sand particles or the like, an etching layer realized by applying an etchant, or the like.

[0018]

The present invention has the following operation corresponding to the above configuration.

That is, as described above, the vacuum sealing structure of the metal vacuum container of the present invention has a double structure of a metal inner container and an outer container, and is provided at a predetermined position of the outer container by a molten sealing material. In a metal vacuum insulating container provided with an exhaust port to be melt-sealed, an uneven surface is formed at the edge of the exhaust port to form a bonding surface with a fusion sealing material. The bonding area and the degree of bonding with the porous material are increased, and the bonding strength is greatly improved.

Therefore, this configuration is effective not only for the above-mentioned metallic brazing material, but also for a glass-based low melting point brazing material such as a lead borosilicate glass sealing material.

[0021] In this case, when the uneven surface is formed by, for example, a sandblast layer or an etching layer, a uniform uneven surface can be realized relatively easily.

[0022]

As described above, according to the vacuum sealing structure of the metal vacuum container of the present invention, for example, a metal-based sealing material such as an Al, Sn, Ni-based brazing material or a glass-based material such as lead borosilicate glass is used. Even when a low melting point type brazing material such as a sealing material is employed, it is possible to reliably adopt a highly reliable vacuum sealing method.

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

[0024]

(Embodiment 1) FIGS. 1 to 5 show a vacuum sealing structure of a metal vacuum insulation container according to Embodiment 1 of the present invention.

First, FIG. 1 shows the entire structure of the vacuum insulation container 1 in an inverted state before vacuum sealing, and the insulation container 1 has a passive film formed on its surface, for example, stainless steel. The inner container 1A made of metal and the outer container 1B are joined to each other on the mouth portion 2 side to form a double structure, and the inner container 1A is vacuum-sealed in the gap 3 formed therebetween.
A heat insulation structure capable of keeping a vacuum inside is realized.

The inner container 1A has a bottomed bottle shape as shown in the figure, and is supported by the outer container 1B at the mouth 2 side. In the outer container 1B, a bottom plate 6 made of a metal having a passive film such as stainless steel, which also forms a part of the outer container, is integrally formed in the opening edge 5 on the side of the bottom 4 whose diameter is reduced by a predetermined dimension. It is formed into a bottomed cylindrical body which is fitted (inner fitting) and welded.

The bottom plate 6 has a peripheral portion 6a bent into a hook shape to form a joint with the opening edge portion 5 of the outer container 1B, and a ring-shaped convex portion (inside of the peripheral portion 6a). Rib 7 is formed.

At the center of the bottom plate 6, there is provided a flat circular exhaust port 8 which is recessed by a predetermined depth toward the inner container 1A as shown in the figure. The exhaust port 8 is
The inside of the container is in the shape of a mortar having a tapered surface that gradually descends at a predetermined inclination angle from the upper end side to the bottom in the inverted state of the container shown in FIG. 10 are formed. The exhaust port 10 communicates with the space 3 between the inner container 1A and the outer container 1B.

On the other hand, an oxide layer 9 is formed on the entire inner surface of the exhaust port 8, and the passive layer on the surface of the bottom plate 6 made of metal such as stainless steel is formed by the oxide layer 9. The coating layer has been increased to achieve a passive surface rich in oxygen content.

The above-described exhaust port 8 at the bottom of the vacuum insulating container 1 made of metal before being vacuum-sealed as shown in FIG.
As shown in FIG. 3, for example, a solid brazing material (solid sealing material) 11 having a cylindrical shape for vacuum sealing is fitted and installed.

As the solid brazing material 11, for example, a glass brazing material having a low melting point (400 to 600 ° C.) such as lead borosilicate glass is used.

Then, as described above, the solid brazing material 11
The metal vacuum insulated container 1 fitted with the is further transferred into a vacuum furnace and first degassed at a predetermined temperature lower than the melting point of the solid brazing material 11 (baking step). It is heated at a temperature higher than the melting point of the brazing material 11 (sealing step). As a result, the solid brazing material 11 melts and flows downward, is guided by the tapered surface of the inner periphery of the exhaust port 8, reaches the interior of the exhaust port 10 formed at the center of the bottom 8 a, and stops. By cooling and hardening in this state, the exhaust port 10 is reliably filled and sealed with sufficient bonding strength as shown in FIG.

That is, in the vacuum sealing structure of the metal vacuum insulation container of the present embodiment, an exhaust port 8 having a tapered surface descending at the center of the bottom plate 6 is formed and the exhaust port 8 is formed.
An exhaust port 10 is formed at the center of the small diameter bottom portion 8a where the tapered surface of the lower portion merges, and the molten brazing material 11 is reliably guided to the exhaust port 10 portion by the tapered surface. Therefore, the vacuum sealing under the low melting point is easily performed simply by fitting the solid brazing material 11 of the columnar shape made of the above-described low melting point metal material into the exhaust port portion 8 having the predetermined depth. be able to.

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

In addition, as described above, since the passivation film having oxygen is sufficiently increased by the oxide layer 9 on the inner surface of the exhaust port 8, the low-melting glass brazing material 11 having an oxygen bond is formed. Has good bondability and high bonding strength,
The reliability of the sealing function is improved.

Further, in the above case, since the brazing material 11 is a solid in the shape of a columnar body and is securely fitted in the exhaust port portion 8 having a sufficient depth before being melted, Even if the carrier frame shakes during the transfer into the inside, there is no danger of dropping, and the holding state is ensured.

When the oxide layer 9 is continuously formed not only on the inner surface of the exhaust port 8 as described above, but also on the back side through the exhaust port 10 as shown in FIG. The wraparound of the material 11 is improved, and the bonding strength is further improved.

(Embodiment 2) Next, FIGS. 6 and 7 show a vacuum sealing structure of a metal vacuum heat insulating container according to Embodiment 2 of the present invention.

Also in this embodiment, the heat insulating container 1 itself is made of a metal inner container 1A having a passive film formed on its surface, such as stainless steel as shown in FIG. To form a double structure, and a vacuum insulation of the inner space 1A is realized by vacuum-sealing the gap 3 formed therebetween.

The inner container 1A has a bottomed bottle shape as shown in the figure, and is supported by the outer container 1B on the mouth 2 side. In the outer container 1B, a bottom plate 6 made of a metal having a passive film such as stainless steel, which also forms a part of the outer container, is integrally formed in the opening edge 5 on the side of the bottom 4 whose diameter is reduced by a predetermined dimension. It is formed into a bottomed cylindrical body which is fitted (inner fitting) and welded.

The bottom plate 6 has its peripheral edge 6a bent in a hook shape to form a joint with the opening edge 5 of the outer container 1B, and has a ring-shaped ridge (inside of the peripheral edge 6a). Rib 7 is formed.

On the other hand, in the center of the bottom plate 6, unlike the first embodiment, as shown in FIG. A mouth 8 is provided. That is, as shown in the figure, the exhaust port 8 is firstly recessed into the inner container 1A side by a predetermined depth in a one-step cylindrical shape on the flat bottom surface at the center of the bottom plate 6 so as to fit a solid brazing material. A concave portion 21 having a diameter is formed, and a funnel portion 8b is formed by further denting the bottom portion 21a of the inner container 1A side in two stages. The funnel portion 8b has a mortar shape having a tapered surface that gradually descends from the upper end side to the bottom at a predetermined inclination angle in the inverted state of the container shown in FIG.
An exhaust port 10 is formed at the center of a. The exhaust port 1
Numeral 0 communicates with the space 3 between the inner container 1A and the outer container 1B.

A metal plating layer 12 corresponding to the brazing material 11 is formed on the entire inner surface of the funnel portion 8b of the exhaust port portion 8 in place of the oxide layer 9 on the inner surface of the funnel portion 8b. A non-passive surface having good wettability with the molten brazing material 11 is realized by the metal plating layer 12.

The recess 21 on the bottom of the exhaust port 8 at the bottom of the vacuum vessel 1 made of metal before being vacuum-sealed as described above.
As shown in the figure, for example, a solid brazing material (solid sealing material) 11 having a cylindrical shape for vacuum sealing is fitted and installed. Then, the solid brazing material 11 is heated and melted in the vacuum furnace after the completion of deaeration in the same manner as in the first embodiment.

The solid brazing material 11 includes, for example, Al, Sn, N
A metal-based brazing material having a low melting point (400 to 600 ° C.) such as an i-based brazing material is used.

According to the structure of this embodiment, the funnel portion 8b
By applying an appropriate metal plating corresponding to various metal-based brazing materials 11 to be used on the inner surface of the metal brazing material 11, the wettability with the metal-based brazing material 11 is particularly improved. Sealing function and reliability are further improved.

As the metal plating layer 12, for example, when the solid brazing material 11 to be used is a metal brazing material of Al, Sn, Ni or the like, a copper plating layer is suitable.

Then, the metal plating layer 12 passes through not only the inner surface side of the exhaust port 8 as shown in FIG. 6 but also the exhaust port 10 as shown in FIG. In this case, the molten brazing material 1 also passes through the exhaust port 10 in the radial direction on the back side of the exhaust port 8.
1 is appropriately and smoothly introduced in a predetermined amount, so that the joining strength is further improved.

Third Embodiment Next, FIG. 8 shows a vacuum sealing structure of a metal vacuum sealing container according to a third embodiment of the present invention.

In this embodiment, as shown in FIG.
The oxide layer 9 of the first embodiment or the metal plating layer 1 of the second embodiment is formed on the entire inner surface of the exhaust port 8 having the same cross-sectional structure as
In place of 2, the bonding area with the brazing material 11 is increased,
And the uneven surface formed of the sandblast layer 13 in which the engaging force at the time of joining is increased is formed, and the bonding area of the brazing material 11 is increased and the engaging force at the time of joining is increased by a large number of uneven surfaces of the sandblast layer 13, A high bonding strength with the molten brazing material 11 similar to that of the first and second embodiments is realized.

According to the structure of this embodiment, the mechanically bonded state with the brazing material 11 after cooling and hardening is improved by the uneven surface of the sandblast layer 13, so that the bonding strength is increased,
The sealing function and reliability of the exhaust port sealing portion are sufficiently improved. And in the case of the said structure, it can be employ | adopted for both a metal brazing material and a glass brazing material.

(Embodiment 4) Next, FIG. 9 shows a vacuum sealing structure of a metal vacuum insulation container according to Embodiment 4 of the present invention.

In this embodiment, as shown in FIG.
An etching layer 14 which is a chemically processed surface is formed on the entire inner surface of the exhaust port portion 8 having the same cross-sectional structure as that of the third embodiment instead of the sand blast layer 13 of the third embodiment which is a machined surface. As with Example 3, the surface of the concavo-convex surface having a large bonding area with the brazing material 11 and a large engaging force at the time of joining is realized. The etching layer is formed using, for example, oxalic acid, hydrochloric acid, aqua regia, or the like.

Also according to the structure of this embodiment, the joining strength with both the metal-based and glass-based molten brazing material 11 is sufficiently high as in the case of the above-described Embodiment 3, so that the sealing function of the exhaust port sealing portion and the reliability are improved. The property is sufficiently improved.

(Embodiment 5) FIG. 10 shows a vacuum sealing structure of a metal vacuum insulation container according to Embodiment 5 of the present invention.

Also in this embodiment, the target vacuum insulated container 1 itself is constructed by joining an inner container 1A made of metal such as stainless steel and an outer container 1B to each other at the mouth 2 side as shown in FIG. It has a structure, and realizes a heat insulating structure capable of maintaining a vacuum inside the inner container 1A by vacuum-sealing the gaps 3 formed therebetween.

The inner container 1A has a bottomed bottle shape as shown in FIG.
B is supported. In addition, the outer container 1B is provided with a bottom plate
Are integrally formed (inner fitting) into a bottomed cylindrical body.

However, in this embodiment, the bottom plate 6 is
As shown in FIG. 10, it is formed of a clad steel plate in which, for example, a copper plate 62 having good wettability with a metallic brazing material is bonded to the outside of a stainless steel plate 61 similar to the outer container 1B.

At the center of the bottom plate 6 made of the clad steel plate, as shown in FIG. 10, exactly the same as in the first embodiment described above, which is recessed in the inner container 1A side by a predetermined depth into a mortar shape. An exhaust port 8 is provided.

Therefore, according to the structure of this embodiment, the inner surface of the exhaust port 10 is a copper plate surface, and the wettability with the metal-based molten brazing material 11 is improved as in the case of the second embodiment. Therefore, the sealing function and reliability of the exhaust port sealing portion are similarly improved.

The copper plate 62 is suitable, for example, when the solid brazing material 11 to be used is an Al or Sn, Ni-based metal brazing material.

Then, the copper plate 62 of the clad steel plate is used.
The material is not limited to a copper plate at all, and an appropriate material is selected according to the type of the brazing material 11 to be used.

(Embodiment 6) FIG. 11 shows a vacuum sealing structure of a metal vacuum insulation container according to Embodiment 6 of the present invention.

Also in this embodiment, the target vacuum insulated container 1 itself is formed by joining an inner container 1A made of metal such as stainless steel and an outer container 1B to each other at the mouth 2 side as shown in FIG. It has a structure, and realizes a heat insulating structure capable of maintaining a vacuum inside the inner container 1A by vacuum-sealing the gaps 3 formed therebetween.

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

On the other hand, the bottom plate 6 has an opening edge 5
A shock absorbing rib 7 bulging outward in a reverse U-shaped cross section is formed radially inward from the peripheral edge 6a by a predetermined distance from the peripheral edge 6a.

At the center of the bottom plate 6 inside the rib 7, an exhaust port 20 substantially similar to that of the second embodiment is provided. That is, the exhaust port portion 20 forms a concave portion 21 having the same diameter by first recessing the flat bottom surface at the center of the bottom plate 6 into the inner container 1A by a predetermined depth in a single step as shown in the figure. Together with the bottom 21a
Is formed in the inner container 1A side in a reverse trapezoidal shape to form a funnel portion 22 having a tapered surface which descends from the upper end to the bottom portion 22a at a predetermined inclination angle so as to gradually reduce the diameter in the inverted state of the container. ing. And
An exhaust port 10 is provided at the center of the small diameter bottom portion 22a of the funnel portion 22.
Are formed. The opening diameter of the upper end of the funnel part 22 is formed smaller than the inner diameter of the concave part 22 having the same diameter on the upper side. A metal plating layer 9 corresponding to the brazing material 11 used in the second embodiment is formed on the inner surface of the funnel 22. Further, the exhaust port 10 communicates with the inside of the space 3 between the inner container 1A and the outer container 1B of the metal vacuum insulation container 1.

In the concave portion 21 of the exhaust port 20 of the metal vacuum insulating container 1 before the vacuum sealing configured as described above, the concave portion 21 is located, for example, between both ends (diameter line portion) of the bottom 21a. A cylindrical (rod-shaped) solid brazing material 11 for vacuum sealing similar to that of Example 1 is fitted and installed.

Then, the solid brazing material 11
Is further transferred into a vacuum furnace, and is first degassed through an exhaust port 10 at a predetermined temperature lower than the melting point of the solid brazing material 11 (baking step). Thereafter, the solid brazing material 11 is further heated at a temperature higher than the melting point thereof (sealing step). As a result, the cylindrical solid brazing material 11 melts and flows downward,
The bottom portion 22 is guided by the tapered surface of the funnel portion 22.
a It reaches the exhaust port 10 formed in the center and is stored.
As shown by a virtual line in FIG. 1, the exhaust port 10 is securely filled and sealed.

Then, after cooling, the vacuum sealing is completed.

According to the above-described structure, the non-passive surface made of the metal plating layer 9 is formed on the inner surface of the exhaust port portion 20 as in the case of the second embodiment.
At the same time as the joining strength of the exhaust port 20 increases, the rib 7 having a U-shaped cross section for absorbing shock is provided between the outer peripheral side bottom plate peripheral edge 6a of the exhaust port 20 and the outer container when the container falls. The impact force acting on the bottom 4 is damped at the bent portion of the rib 7 and does not significantly act on the exhaust port 20 portion. Therefore, the hardened brazing material 11 hardly peels off from the exhaust port 10, and the durability and reliability of the sealing portion are greatly improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an entire metal vacuum heat insulating container according to a first embodiment of the present invention.

FIG. 2 is a plan view of the same bottom.

FIG. 3 is a cross-sectional view of an exhaust port at the bottom.

FIG. 4 is a sectional view of the exhaust port in a vacuum sealed state.

FIG. 5 is a sectional view of a modified example of the exhaust port.

FIG. 6 is an enlarged cross-sectional view of an exhaust port at the bottom of a metal vacuum insulated container according to Embodiment 2 of the present invention.

FIG. 7 is an enlarged cross-sectional view of a modified example of the exhaust port at the bottom of the metal vacuum insulation container.

FIG. 8 is an enlarged cross-sectional view of an exhaust port at the bottom of a metal vacuum insulated container according to Embodiment 3 of the present invention.

FIG. 9 is an enlarged cross-sectional view of an exhaust port at the bottom of a metal vacuum insulated container according to Embodiment 4 of the present invention.

FIG. 10 is an enlarged sectional view of a bottom portion of a metal vacuum insulated container according to a fifth embodiment of the present invention.

FIG. 11 is an enlarged cross-sectional view of a bottom portion of a metal vacuum insulated container according to a sixth embodiment of the present invention.

FIG. 12 is a sectional view showing an exhaust structure of a metal vacuum heat insulating container according to a first conventional example.

FIG. 13 is a sectional view showing an exhaust structure of a metal vacuum heat insulating container according to a second conventional example.

FIG. 14 is a sectional view showing an exhaust structure of a metal vacuum heat insulating container according to a third conventional example.

FIG. 15 is a plan view of the exhaust port.

FIG. 16 is a sectional view of the exhaust port.

FIG. 17 is a sectional view showing an exhaust structure of a metal vacuum heat insulating container according to a fourth conventional example.

FIG. 18 is a plan view showing a configuration of an exhaust port at the bottom of the metal vacuum heat insulating container.

FIG. 19 is a sectional view of the exhaust port.

FIG. 20 is a sectional view showing an exhaust structure of a metal vacuum heat insulating container according to a fifth conventional example.

FIG. 21 is a plan view showing the structure of an exhaust port at the bottom of the metal vacuum insulation container.

FIG. 22 is a sectional view of the exhaust port.

[Explanation of symbols]

1 is a metal vacuum container, 2 is a mouth, 3 is a gap, 4 is a bottom of an outer container, 6 is a bottom plate, 8 and 20 are exhaust ports, 9 is an oxide layer, 10 is an exhaust port, and 11 is a solid brazing material. , 12 is a metal plating layer, 13 is a sandblast layer, and 14 is an etching layer.

Claims (3)

(57) [Claims] 1. A metal vacuum heat insulating container having a double structure of a metal inner container and an outer container, and having an exhaust port melt-sealed by a melt sealing material at a predetermined position of the outer container. A vacuum-sealed structure for a metal vacuum heat-insulating container, characterized in that a concave / convex processed surface forming a joint surface with a molten sealing material is formed at an edge of an exhaust port. 2. The vacuum sealing structure of a metal vacuum heat insulating container according to claim 1, wherein the uneven surface is formed by a sandblast layer. 3. The vacuum sealing structure for a metal vacuum container according to claim 1, wherein the uneven surface is formed by an etching layer.