JP2013255661A - Double-walled vacuum container and method of producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a double-walled vacuum container formed with a welded portion between a body portion and a bottom portion of an outer container at a part inconspicuous to the user to increase designability, having a simplified welding step and having a reduced manufacturing cost.SOLUTION: A double-walled vacuum container 1 is provided with a vacuum insulation layer 4 between a metal inner container 2 having a substantially bottomed cylindrical shape and a metal outer container 3 having a substantially bottomed cylindrical shape. The outer container 3 has a body portion 31, whose bottom-side end bent inward to form a bent portion 311. The outer container 3 has a separated bottom portion 31 disposed to close an opening 313 formed at the end edge of the bent portion 311. The bent portion 311 and a bottom portion 33 are fixedly welded at the bottom side of the outer container 3.

Description

  The present invention relates to a vacuum double container such as a portable thermos and a method for producing the same.

  Conventionally, as a portable thermos, a substantially bottomed cylindrical metal inner container and a substantially bottomed cylindrical metal outer container are arranged with a space open, and the space is evacuated and evacuated. A vacuum double container in which a vacuum heat insulating layer is provided between an inner container and an outer container is known. The inner container and the outer container are formed into a predetermined shape by performing necessary processing such as welding of another member. For example, in the outer container, a bottom cover is provided at the bottom end of the cylindrical body. Standing parts that rise from the peripheral edge of the bottom member or the bottom member are fitted inside or outside, and are welded circumferentially at the tip of the standing part or the bottom side end of the body part to form a predetermined shape (Patent Document) 1 and 2).

JP 59-103633 A JP 2011-206408 A

  By the way, the vacuum double container of the portable thermos, the part where the body part and the bottom part of the outer container are fitted and welded appears as a circumferential line of steps on the peripheral side surface of the outer container, Since the peripheral side surface of the outer container is easy to catch the eye of the consumer, it is desirable to improve the design by forming such a welded part in a place where it is difficult to catch the eye of the consumer. Moreover, in the manufacture of a vacuum double container, it is also required to simplify the welding process and reduce the manufacturing cost.

  This invention proposes in view of the said subject, Comprising: While forming the welding part of the trunk | drum and bottom part of an outer container in a location which is hard to catch a consumer's eyes, while being able to improve design property, a welding process is carried out. An object of the present invention is to provide a vacuum double container that can be simplified and reduced in manufacturing cost, and a manufacturing method thereof.

The vacuum double container of the present invention is a vacuum double container in which a vacuum heat insulating layer is provided between a substantially bottomed cylindrical metal inner container and a substantially bottomed cylindrical metal outer container, The bottom part of the separate body of the outer container is formed so that a bottom part of the bottom part of the body part of the outer container is bent inward to form a bent part, and the opening formed at the leading edge of the bent part is closed. Is arranged, and the bent portion and the bottom portion are fixed by welding on the bottom side of the outer container.
According to this configuration, it becomes possible to form the welded portion between the body and the bottom of the outer container of the vacuum double container on the bottom side of the outer container, and to form this welded part in a place where it is difficult to catch the eyes of the consumer, Design can be improved. Also, for example, there is no need to move the laser head of the laser welding machine in the circumferential direction, the welding direction can be one direction toward the bottom side of the outer container, and welding is performed on the peripheral side surface of the outer container. Since the welding length can be made shorter than in the case of making it, the welding process can be simplified and the manufacturing cost can be reduced.

The vacuum double container of the present invention is provided with a bent step portion formed by bending toward the inner container side and the opening side in the vicinity of the tip of the bent portion, and the bottom portion of the outer container at the bent step portion. It is arranged to be overlapped and welded.
According to this configuration, by placing the bottom portion on the bent stepped portion and welding, it is possible to eliminate the portion protruding from the peripheral side surface on the bottom side of the outer container, and further improve the design by enhancing the aesthetic appearance. Can do.

The vacuum double container of the present invention is characterized in that a peripheral edge of a bottom portion of the outer container is welded to the bent portion by laser welding.
According to this configuration, it is possible to weld and fix the bent portion and the bottom portion of the body portion of the outer container precisely with low distortion, and it is possible to reduce the residual stress of the vacuum double container and prevent deformation during welding. it can.

In the vacuum double container of the present invention, a skirt is formed on the bottom side of the mouth of the outer container, which is a separate body from the body of the outer container, and the tip of the mouth of the shell and the tip of the skirt And are welded by laser welding.
According to this structure, it is possible to enhance functionality by using different materials for the body and the mouth by making the body and mouth of the outer container separate, for example, direct contact with water. The outer container and the vacuum double container can be reduced in weight by using a lightweight material, although the corrosion resistance is inferior, for the trunk portion of the small outer container. In addition, for example, by welding the part so as to have a required shape by laser welding, and polishing as necessary, the part can be formed into an acute round shape with little roundness or a round shape with a relatively large roundness. It is possible to easily adjust the shape of the welded portion with a high degree of freedom, and to improve and diversify the design. In addition, it is easy to make the welded portion of the portion inconspicuous on the peripheral side surface of the outer container, and from this point, the design can be improved.

The vacuum double container of the present invention is characterized in that a suction hole for vacuum suction is formed in the center of the bottom of the outer container.
According to this configuration, the suction hole at the bottom can be used for centering, and processing related to the bottom and processing for the container after joining the bottom are facilitated.

The vacuum double container of the present invention is characterized in that the bottom part of the outer container is disposed by being fitted into the bent step part.
According to this configuration, the bottom can be easily aligned and fixed at an accurate position.

The manufacturing method of the vacuum double container of the present invention is a vacuum double container in which a vacuum heat insulating layer is provided between a substantially bottomed cylindrical metal inner container and a substantially bottomed cylindrical metal outer container. 1st process which is a manufacturing method, Comprising: The 1st process of forming a bending part so that the edge part of the bottom side of the trunk | drum which comprises the said outer container may be bent inside, and the opening formed by the front-end edge of the said bending part A second step of disposing a separate bottom part constituting the outer container so as to close the container, and a third step of welding and fixing the bent part and the bottom part on the bottom side of the outer container; It is characterized by providing.
According to this configuration, it becomes possible to form the welded portion between the body and the bottom of the outer container of the vacuum double container on the bottom side of the outer container, and to form this welded part in a place where it is difficult to catch the eyes of the consumer, Design can be improved. Also, for example, there is no need to move the laser head of the laser welding machine in the circumferential direction, the welding direction can be one direction toward the bottom side of the outer container, and welding is performed on the peripheral side surface of the outer container. Since the welding length can be made shorter than in the case of making it, the welding process can be simplified and the manufacturing cost can be reduced.

The manufacturing method of the vacuum double container according to the present invention includes a bent step portion formed by pressing the vicinity of the tip of the bent portion and bending the inner container side and the opening side in the first step. And in the second step, the bottom portion constituting the outer container is disposed so as to overlap the bent stepped portion.
According to this configuration, by placing the bottom portion on the bent stepped portion and welding, it is possible to eliminate the portion protruding from the peripheral side surface on the bottom side of the outer container, and further improve the design by enhancing the aesthetic appearance. Can do. Further, the bent step portion can be easily formed by press working.

The manufacturing method of the vacuum double container of the present invention is characterized in that, in the third step, the peripheral edge of the bottom part constituting the outer container is welded to the bent part by laser welding.
According to this configuration, it is possible to weld and fix the bent portion and the bottom portion of the body portion that constitutes the outer container with low distortion, and to reduce the residual stress of the vacuum double container and prevent deformation during welding. be able to.

The method for manufacturing a vacuum double container according to the present invention includes a mouth-side tip of a body part that constitutes the outer container and a tip part of a skirt part that is formed on the bottom side of a separate mouth part that constitutes the outer container. Are aligned and arranged and welded by laser welding.
According to this structure, it is possible to enhance functionality by using different materials for the body and the mouth by making the body and mouth of the outer container separate, for example, direct contact with water. The outer container and the vacuum double container can be reduced in weight by using a lightweight material, although the corrosion resistance is inferior, for the trunk portion of the small outer container. In addition, for example, by welding the part so as to have a required shape by laser welding, and polishing as necessary, the part can be formed into an acute round shape with little roundness or a round shape with a relatively large roundness. It is possible to easily adjust the shape of the welded portion with a high degree of freedom, and to improve and diversify the design. In addition, it is easy to make the welded portion of the portion inconspicuous on the peripheral side surface of the outer container, and from this point, the design can be improved.

The method for manufacturing a vacuum double container according to the present invention includes, in the first step, forming a basic bent portion or a basic bent step portion that is a base of the bent portion or the bent step portion, and the basic bent portion. Alternatively, the bent portion or the bent stepped portion is formed by cutting and removing the vicinity of the tip of the basic bent stepped portion.
According to this configuration, it is possible to form a bent portion or a bent step portion having a thin and stable diameter without wrinkles.

  According to the present invention, the welded portion of the body and bottom of the outer container of the vacuum double container can be formed in a place where it is difficult to catch the eye of the consumer, the design can be improved, and the welding process is simplified, Manufacturing costs can be reduced.

The front view of the vacuum double container of embodiment by this invention. The longitudinal cross-sectional view of the vacuum double container of embodiment by this invention. The partial expanded sectional view which shows the peripheral region of the welding part of the trunk | drum of an outer container, and an opening | mouth part. (A) is a partial expanded sectional view which shows the peripheral region of the welding part of the trunk | drum and bottom part of an outer container, (b) is the elements on larger scale of the A section. (A) is sectional drawing which shows the cylinder used as the opening part of an outer container, (b) is sectional explanatory drawing which shows the opening part of an outer container. The fragmentary sectional view which shows the state which inserted and welded the inner container in the opening | mouth part of the outer container. (A) is sectional drawing which shows the cylinder used as the trunk | drum of an outer container, (b)-(c) is explanatory drawing explaining the process in the edge part of the bottom side of a cylinder. (A) is sectional drawing which shows the trunk | drum of an outer container, (b) is sectional drawing which shows the state which has arrange | positioned the separate bottom part in the trunk | drum of an outer container. Sectional drawing which shows the state which welded the trunk | drum and bottom part of the outer container.

[Vacuum Double Container of Embodiment and Manufacturing Method Thereof]
The vacuum double container 1 of this embodiment is a portable thermos bottle, and as shown in FIGS. 1 and 2, a substantially bottomed cylindrical metal container 2 and a substantially bottomed cylindrical metal outer container. A space is provided between the inner container 2 and the outer container 3, and the space is a vacuum heat insulating layer 4 that is evacuated by vacuum suction.

  The inner container 2 has a substantially bottomed cylindrical main body 21, as shown in FIGS. 2 to 4, and an opening 23 is provided at the end of the main body 21 on the opening side via a constricted portion 22. Yes. A spiral groove 231 into which a lid member (not shown) is screwed is formed in the mouth portion 23, and a diameter-enlarged portion 232 is formed in the vicinity of the tip on the opening side.

  As shown in FIGS. 1 to 4, the outer container 3 includes a substantially cylindrical body portion 31, and a mouth portion 32 provided at one end of the body portion 31 that is the mouth side of the vacuum double container 1, It has a bottom 33 provided at the other end of the body 31 that is the bottom of the vacuum double container 1. The body portion 31, the mouth portion 32, and the bottom portion 33 are separate bodies, and are joined to each other by welds 52 and 53 described later.

  The other end portion of the body portion 31 is bent inward to form a bent portion 311, and an opening 313 is formed with the tip edge of the bent portion 311 as a peripheral edge. Further, a bent step portion 312 formed so as to be bent toward the inner container 2 side and the opening 313 side is provided near the tip of the bent portion 311, in other words, the opening 313 is bent and bent. The tip edge of the portion 312 is formed as a peripheral edge.

  The mouth portion 32 has a substantially cylindrical shape, and a folded portion 321 bent inward is formed at one end portion of the mouth portion 31 on the mouth side, and the other end of the mouth portion 31 on the bottom side. At the end, a skirt 322 is formed that is widened toward the end and has a substantially bowl shape near the tip.

  The folded portion 321 is fitted inside the enlarged diameter portion 232 to a position where the tip is substantially in contact with the root of the enlarged diameter portion 232 of the inner container 2, and the distal end of the folded portion 321 is on the inner surface of the mouth portion 23 of the inner container 2. It is fixed by welding by laser welding. By this welding, a welded portion 51 is formed along the circumferential direction at a location where the tip of the folded portion 321 substantially contacts the base of the enlarged diameter portion 232.

  The skirt 322 is disposed such that the tip thereof is in contact with the mouth-side tip of the body 31, and the tip of the skirt 322 and the mouth-side tip of the body 31 are fixed by laser welding. A weld 52 is formed along the circumferential direction. The shoulder of the outer container 3 constituted by the contact between the tip of the bottom 322 and the mouth-side tip of the body 31 and the welded portion 52, or the welded portion 52 is sharpened with little roundness by, for example, polishing. A round shape or a round shape having a relatively large roundness is formed.

  The bottom 33 has a substantially plate shape such as a substantially disk shape, and a suction hole 331 for vacuum suction is formed at the center of a concave portion formed so as to be recessed inward. A getter 332 that absorbs gas in the space between the inner container 2 and the outer container 3 after sealing the suction hole 331 is provided on the inner surface side of the bottom 33.

  The bottom 33 is disposed so as to close the opening 313. In the present embodiment, the bottom portion 33 is disposed so as to overlap the bending step portion 312, and the side end surface of the bottom portion 33 is disposed close to the side surface of the bending step portion 312 or is substantially in contact with the side surface of the bending step portion 312. It is fitted so as to be in contact with each other, and the vicinity of the periphery of the bottom 33 is disposed so as to overlap the tip surface of the bent stepped portion 312 extending in the bottom direction of the vacuum double container 1. The depth of the concave portion formed by the bending step portion 312, that is, the height of the side surface of the bending step portion 312 is formed deeper or higher than the thickness of the bottom portion 33, and the bottom portion 33 is formed by the bending step portion 312. So that it does not protrude from the bottom end of the bent portion 311 to the bottom side.

  The bottom 33 and the bent portion 311 are fixed by welding on the bottom side of the outer container 3, and the peripheral edge of the bottom portion 33 is welded to the bent portion 311 by laser welding, and the circumferential shape is formed on the bottom side of the outer container 3. A welded portion 53 is formed. In the present embodiment, the periphery of the bottom portion 33 is welded by laser welding in the vicinity of the corner of the bent step portion 312.

  The vacuum heat insulating layer 4 is a vacuum or decompressed space formed between the inner container 2 and the outer container 3. The vacuum heat insulating layer 4 may be provided with a vacuum heat insulating material, for example, by applying a metal foil such as copper or aluminum to the outer surface of the inner container 2 or the inner surface of the outer container 3.

  When the vacuum double container 1 is manufactured, as shown in FIGS. 5 (a) and 5 (b), the cylindrical body 32a constituting the mouth portion 32 of the outer container 3 is subjected to required processing, and one end portion The folded end 321 is formed by bending the tip of the inner side, and the flared portion is applied to the other end to form the skirt 322, thereby forming the mouth 32.

  Next, as shown in FIG. 6, the inner container 2 or a constituent member thereof is inserted inside the mouth portion 32, and the folded portion 321 of the mouth portion 32 and the mouth portion 23 of the inner container 2 or the mouth portion of the constituent member thereof. Weld and fix inside the mouth. In the illustrated example, until the distal end of the folded portion 321 of the mouth portion 32 substantially comes into contact with the root of the enlarged diameter portion 232 or the like formed in the vicinity of the distal end of the mouth portion 23 of the inner container 2 or the mouth portion of the constituent member, The folded portion 321 is fitted inside the enlarged diameter portion 232 and the like, and the tip of the folded portion 321 of the mouth portion 32 is welded to the inner surface of the mouth portion 23 of the inner container 2 or the mouth portion of the constituent member thereof. It is applied in the direction and fixed by the welded portion 51. In addition, when the component member of the inner container 2 is fixed to the mouth portion 32, in an appropriate step before the step of arranging and fixing the body portion 31 and the bottom portion 33 of the outer container 3 described later to the mouth portion 32. The inner container 2 is completed.

  Further, in the manufacture of the vacuum double container 1, as shown in FIG. 7, the end part on the bottom side of the cylindrical body 31 a constituting the body part 31 of the outer container 3 is bent inward to form a bent part 311. When forming the bent portion 311 in this example, the end portion on the bottom side of the cylindrical body 31a is bent inward by roll molding or the like to form the bent portion 311a that is the basis of the bent portion 311. Then, the vicinity of the tip of the bent portion 311a is pressed to form a base bending step portion 312a so as to be bent toward the opening formed by the inner container 2 side and the tip edge of the bent portion 311a. By cutting and removing the vicinity of the tip of the portion 312a, the bent step portion 312 is formed, and the bent portion 311 having the bent step portion 312 is formed. The bending step 312 is formed to bend toward the opening 313 formed by the inner container 2 side and the leading edge of the bent portion 311.

  Next, as shown in FIG. 8, a separate bottom 33 constituting the outer container is disposed so as to close the opening 313 formed at the leading edge of the bent portion 311, and in this example, the bottom 33 is bent to a bent stepped portion. It arrange | positions so that it may overlap with 312 and it arrange | positions so that the side end surface of the bottom part 33 may adjoin the side surface of the bending | flexion level | step-difference part 312. FIG. In addition, it is preferable that the side end surface of the bottom portion 33 is fitted and disposed so as to be substantially in contact with the side surface of the bent stepped portion 312 because the bottom portion 33 can be easily aligned and fixed at an accurate position.

  Next, as shown in FIG. 9, the bent portion 311 and the bottom portion 33 are welded and fixed on the bottom side of the outer container 3. In this example, the bottom portion 33 is arranged on the body portion 31 so as to overlap the bent stepped portion 312, the arrangement state is held by jigs 61 and 62, and the periphery of the bottom portion 33 is laser-welded to the bent portion 311. Weld. The periphery of the bottom portion 33 is welded by laser welding in the circumferential direction in the vicinity of the corner of the bent stepped portion 312, so that the body portion 31 and the bottom portion 33 are fixed by the welded portion 53. In this example, the suction hole 331 provided at the center of the bottom 33 is used for centering during welding, and the centering rod 611 of the jig 61 is inserted into the suction hole 331 for welding. .

  And after attaching the getter 332 to the inner surface side of the bottom part 33 in the state where the trunk | drum 31 and the bottom part 33 were fixed, the front end of the trunk | drum 31 which comprises the outer container 3, and another which comprises the outer container 3 The tip of the bottom part 322 formed on the bottom side of the mouth part 32 of the body is aligned and disposed, and welding is performed by laser welding in the circumferential direction, and a welded part 52 is formed and fixed. When forming the welded portion 52, the portion is welded so as to have a required shape by laser welding, and polished as necessary, so that an acute round shape with little roundness or a round shape with a relatively large roundness is obtained. Form in shape. Furthermore, the vacuum double container 1 can be obtained by performing necessary processes such as vacuum suction and exhaustion.

  According to the vacuum double container 1 of the first embodiment or the manufacturing method thereof, the welded portion of the body 31 and the bottom 33 of the outer container 3 of the vacuum double container 1 is set to the bottom side of the outer container 3, and this welded part Can be formed in places where it is difficult to catch the eye of the consumer, and the design can be improved. Further, for example, there is no need to move the laser head of the laser welding machine in the circumferential direction, the welding direction can be one direction toward the bottom side of the outer container 3, and the circumferential side surface of the outer container 3 Since the welding length can be shortened compared with the case where welding is performed, the welding process can be simplified and the manufacturing cost can be reduced.

  Further, by arranging and welding the bottom portion 33 to the bent stepped portion 312, it is possible to eliminate a portion protruding from the peripheral side surface on the bottom side of the outer container 3, and to further enhance the aesthetics and further improve the design. it can. Further, by welding the peripheral edge of the bottom 33 of the outer container 3 to the bent portion 311 by laser welding, the bent portion 311 and the bottom portion 33 of the body portion 31 of the outer container 3 can be welded and fixed precisely. It is possible to reduce the residual stress of the vacuum double container 1 and to prevent deformation during welding. Further, the suction hole 331 for vacuum suction formed at the center of the bottom portion 33 of the outer container 3 can be used for centering, and processing related to the bottom portion 33 and processing of the container after joining the bottom portion 33 are facilitated. Become.

  Also, by making the body 31 and the mouth 32 of the outer container 3 separate, it is possible to enhance the functionality by using different materials for the body 31 and the mouth 32, for example, directly touching water. However, the outer container 3 and the vacuum double container 1 can be reduced in weight by using a lightweight material for the body portion 31 of the outer container 3 with a small amount of corrosion resistance. For example, while the mouth portion 32 of the outer container 3 is made of SUS304 having a specific gravity of about 7.93, the body portion 31 that is less exposed to water is made of SUS430 having poor corrosion resistance and the specific gravity of about 7.70, improving workability and reducing costs. Further, the outer container 3 and the vacuum double container 1 can be reduced in weight.

  In addition, by welding the tip of the skirt 322 of the mouth portion 32, which is a separate body from the tip of the mouth portion 31 of the body portion 31 by laser welding, and polishing as necessary, a sharp rounded shape with less roundness, It is possible to easily adjust the shape of the welded portion 52 with a high degree of freedom, such as a round shape having a relatively large roundness, and to improve design and diversify. Moreover, it is easy to make the welding part 52 inconspicuous in the surrounding side surface of the outer container 3, and also from this point, design property can be improved.

  In addition, by forming the base bending step 312a that is the basis of the bending step 312 and cutting and removing the vicinity of the tip of the base bending step 312a to form the bending step 312, there is no wrinkle and a thin and stable diameter. The bent stepped portion 312 and the bent portion 311 can be formed. Further, the bent stepped portion 312 can be easily formed by pressing.

[Modifications of Embodiment, etc.]
In addition to the configurations of the inventions and embodiments, the invention disclosed in the present specification is specified by changing these partial configurations to other configurations disclosed in the present specification within the applicable range, or these To which the other configurations disclosed in the present specification are added or specified, or those partial configurations are deleted and specified to the extent that partial effects can be obtained. The following modifications are also included.

  For example, the bent portion 311 of the outer container 3 of the above embodiment has the bent step portion 312, but may be a bent portion that is bent inward without having the bent step portion 312. Alternatively, a separate bottom portion of the outer container may be disposed and welded so as to close the opening formed at the leading edge of the bent portion. Also in this case, when the bent portion is formed by forming the bent portion that is the basis of the bent portion and cutting and removing the vicinity of the tip of the bent portion, there is no wrinkle and a thin and stable diameter. A bent portion can be formed, which is preferable.

  Moreover, the manufacturing method of the vacuum double container 1 includes the step of forming the bent portion 311 so that the bottom end portion of the body portion 31 constituting the outer container 3 is bent inward, and the leading edge of the bent portion 311. A step of disposing a separate bottom 33 constituting the outer container 3 so as to close the opening 313 formed by the step of welding and fixing the bent portion 311 and the bottom 33 on the bottom side of the outer container 3 For example, the body part 31 in which the bent part 311 is formed and the mouth part 32 of the outer container 3 are first welded and fixed, and then the bottom 33 is arranged and fixed to the bent part 311. It is good also as a structure which performs.

  The present invention can be used for a vacuum double container such as a portable thermos and its manufacture.

DESCRIPTION OF SYMBOLS 1 ... Vacuum double container 2 ... Inner container 21 ... Main body 22 ... Constriction part 23 ... Mouth part 231 ... Spiral groove 232 ... Expanded diameter part 3 ... Outer container 31 ... Trunk part 31a ... Cylindrical body 311, 311a ... Bending part 312 ... Bending step part 312a ... Basic bending step part 313 ... Opening 32 ... Mouth part 32a ... Cylinder body 321 ... Folding part 322 ... Bottom part 33 ... Bottom part 331 ... Suction hole 332 ... Getter 4 ... Vacuum heat insulating layers 51, 52, 53 ... Welded part 61, 62 ... Jig 611 ... Centering rod

Claims (11)

A vacuum double container in which a vacuum heat insulating layer is provided between a substantially bottomed cylindrical metal container and a substantially bottomed cylindrical metal outer container,
The end on the bottom side of the body portion of the outer container is bent inward to form a bent portion,
A separate bottom portion of the outer container is disposed so as to close an opening formed at a leading edge of the bent portion,
The vacuum double container, wherein the bent part and the bottom part are fixed by welding on the bottom side of the outer container. A bent step portion formed by bending to the inner container side and the opening side is provided near the tip of the bent portion,
The vacuum double container according to claim 1, wherein a bottom portion of the outer container is arranged and welded so as to overlap the bent stepped portion.   The vacuum double container according to claim 1 or 2, wherein a peripheral edge of a bottom portion of the outer container is welded to the bent portion by laser welding. A skirt is formed on the bottom side of the mouth of the outer container, which is a separate body from the body of the outer container,
The vacuum double container according to any one of claims 1 to 3, wherein a front end of the body portion on the mouth side and a front end of the skirt portion are welded by laser welding.   The vacuum double container according to any one of claims 1 to 4, wherein a suction hole for vacuum suction is formed in the center of the bottom of the outer container.   The vacuum double container according to any one of claims 1 to 5, wherein a bottom portion of the outer container is fitted into the bent stepped portion. A method of manufacturing a vacuum double container in which a vacuum heat insulating layer is provided between a substantially bottomed cylindrical metal container and a substantially bottomed cylindrical metal outer container,
A first step of forming a bent portion so as to bend an end portion of a bottom side of a trunk portion constituting the outer container inward;
A second step of disposing a separate bottom portion constituting the outer container so as to close an opening formed at a leading edge of the bent portion;
A third step of welding and fixing the bent portion and the bottom portion on the bottom side of the outer container;
A method for producing a vacuum double container, comprising: In the first step, the vicinity of the tip of the bent portion is pressed to form a bent stepped portion formed by bending the inner container side and the opening side,
In the said 2nd process, it arrange | positions so that the bottom part which comprises the said outer container may overlap with the said bending | flexion level | step-difference part part. The manufacturing method of the vacuum double container of Claim 7 characterized by the above-mentioned. The method for manufacturing a vacuum double container according to claim 7 or 8, wherein, in the third step, a peripheral edge of a bottom part constituting the outer container is welded to the bent part by laser welding.   Laser welding is performed by aligning the tip on the mouth side of the body part constituting the outer container and the tip of the bottom part formed on the bottom side of the separate mouth part constituting the outer container, and performing laser welding. The manufacturing method of the vacuum double container in any one of Claims 7-9 provided with the process welded by. In the first step, a basic bent portion or a basic bent step portion that is a base of the bent portion or the bent step portion is formed, and the vicinity of the tip of the basic bent portion or the basic bent step portion is cut and removed. The manufacturing method of the vacuum double container according to claim 7, wherein the bent portion or the bent stepped portion is formed.

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