Vacuum heat insulation container and method for producing the same

Abstract

To attain the long life and durability improvement of a vacuum heat insulation container by securely obtaining the required vacuum degree of a vacuum heat insulation layer and stably maintaining the same over a long period.SOLUTION: Disclosed is a vacuum heat insulation container 1 in which: a vacuum heat insulation layer 4 is provided between a bottomed, cylindrical, metallic inner container 2 and a bottomed, cylindrical, metallic outer container 3; the outer container 3 is configured from an outer cylinder 31 and a bottom part 32 clogging the bottom side of the outer cylinder 31; an extension wall 313 extending to the inside is installed around a lower part of the outer cylinder 31; an extension bottom plate 321 extending to the outside is installed around the bottom part 32; a tip part of the extension bottom plate 321 is placed on a lower part of the extension wall 313 so as to be face-contacted from the outside; a tip edge of the extension bottom plate 321 is joined to the extension wall 313 at a fillet weld zone 5 on the intermediate position of the extension direction of the extension wall 313; and a vacuum exhaust port 6 provided in the vicinity of the tip edge of the extension bottom plate 321 and locally arranged at a part of the circumferential direction of the bottom part 32 is sealed.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to vacuum insulated containers such as can holders, mugs, soup cups, lunch jars, portable thermoses, and tabletop thermoses, and to a method for manufacturing the same. [Background technology]

[0002] A conventional vacuum insulated container in which a vacuum insulation layer is provided between an inner container and an outer container is the vacuum insulated container disclosed in Patent Document 1. In this vacuum insulated container, a vacuum insulation layer is provided between a cylindrical stainless steel inner container with a bottom and a cylindrical stainless steel outer container with a bottom, and the outer container is formed by a cylindrical portion of the outer container and a bottom portion of the outer container.

[0003] A groove consisting of an L-shaped bent portion having an L-shaped cross section is formed in the circumferential direction in the lower part of the peripheral wall of the tubular outer container, and the peripheral wall of the bottom is fitted longitudinally into this groove so that the surface positions of the peripheral wall of the tubular outer container and the peripheral wall of the tubular outer container are aligned. The tubular outer container and the bottom are joined by externally fitting the peripheral wall of the bottom into the L-shaped bent portion, positioning the tip of the bottom peripheral wall at a position with a gap from the base of the L-shaped bent portion, and welding the tip of the bottom peripheral wall to the L-shaped bent portion (see Figure 5 of Patent Document 1), or by externally fitting the peripheral wall of the bottom into the L-shaped bent portion so that the tip of the bottom peripheral wall abuts the base of the L-shaped bent portion, and spot welding the vicinity of the tip of the bottom peripheral wall to the L-shaped bent portion (see Figure 6 of Patent Document 1).

[0004] When forming this vacuum insulated container, for example, a welding device is placed in a high-temperature vacuum chamber, and a workpiece, which has not been welded at the base of the L-shaped bend in the outer container cylindrical part to the tip of the bottom peripheral wall, is placed in the vacuum chamber, and the workpiece is rotated 360 degrees horizontally using a turntable and drive unit in a sparse air environment, and the L-shaped bend in the outer container cylindrical part is welded to the tip or near the tip of the bottom peripheral wall using beam welding. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-154367 Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the above-described method of manufacturing a vacuum insulated container by placing a workpiece in a vacuum chamber, rotating the workpiece horizontally with a drive unit, and welding the outer container tubular part to the bottom, there is a high possibility that the vacuum state may be contaminated by lubricants such as grease applied to the drive unit that rotates the workpiece, and that air leaks may occur from the connection parts of the drive unit inside and outside the vacuum chamber. As a result, the stability of the vacuum level inside the vacuum chamber decreases, making it difficult to reliably obtain the vacuum level required for the vacuum insulation layer of the vacuum insulated container.

[0007] Furthermore, when a local vacuum exhaust port is provided in the workpiece of the vacuum insulated container and vacuum is exhausted from the vacuum exhaust port, it is desirable that the area around the vacuum exhaust port be configured to achieve both smooth vacuum exhaust and assist in sealing after vacuum exhaust, and to stably maintain the required vacuum level in the vacuum insulation layer of the vacuum insulated container over a long period of time, thereby extending the life and improving the durability of the vacuum insulated container.

[0008] Furthermore, when manufacturing the vacuum insulated container of Patent Document 1, if the bottom peripheral wall is fitted onto the L-shaped bent portion and the tip of the bottom peripheral wall is positioned with a gap from the base of the L-shaped bent portion and then welded, variations in the dimensions of the bottom peripheral wall and the L-shaped bent portion of the outer container tubular part can cause variations in the gap, resulting in poor welding such as burn-through or holes. Alternatively, if the bottom peripheral wall is fitted onto the L-shaped bent portion so that its tip abuts the base of the L-shaped bent portion and the vicinity of the tip of the bottom peripheral wall is spot-welded to the L-shaped bent portion, if a dimensional error occurs such that the outer diameter of the L-shaped bent portion is smaller than the inner diameter of the bottom peripheral wall, the bottom peripheral wall cannot be welded to the L-shaped bent portion along the entire circumference. In other words, the strict dimensional accuracy required when manufacturing the vacuum insulated container of Patent Document 1 can also result in a problem of reduced yield.

[0009] The present invention has been proposed in consideration of the above-mentioned problems, and has an object to provide a vacuum insulated container and a manufacturing method thereof that can reliably obtain the required degree of vacuum in the vacuum insulation layer and stably maintain the required degree of vacuum in the vacuum insulation layer over a long period of time, thereby extending the life and improving the durability of the vacuum insulated container. Another object of the present invention is to provide a vacuum insulated container and a manufacturing method thereof that can increase the dimensional tolerance of the outer tube and the bottom that closes the bottom of the outer tube, thereby improving yield. [Means for solving the problem]

[0010] The vacuum insulated container of the present invention is characterized in that a vacuum insulation layer is provided between a bottomed, cylindrical, metallic inner container and a bottomed, cylindrical, metallic outer container, the outer container being composed of an outer tube and a bottom that closes the bottom side of the outer tube, an extending wall extending inward is provided around the lower part of the outer tube, an extending bottom plate extending outward is provided around the bottom, and the extending bottom plate is stacked from the outside so that the tip of the extending bottom plate is in surface contact with the lower part of the extending wall, the tip edge of the extending bottom plate is joined to the extending wall with a fillet weld at a midpoint in the extension direction of the extending wall, and a vacuum exhaust port provided near the tip edge of the extending bottom plate and locally arranged in a portion of the circumference of the bottom is sealed. According to this configuration, by locating the vacuum exhaust port near the leading edge of the extended bottom plate and locally along a portion of the circumference of the bottom, it is possible to seal the vacuum exhaust port without rotating the workpiece in a vacuum chamber where the vacuum level is stable, thereby reliably achieving the required vacuum level for the vacuum insulation layer of the vacuum insulated container. Furthermore, when evacuating the target space between the inner and outer containers in the vacuum chamber, the extended bottom plate at the bottom, which is located around the vacuum exhaust port, expands outward to promote evacuation from the target space. As the evacuation from the target space progresses, the extended bottom plate deforms to make surface contact with the extended wall, allowing evacuation through the vacuum exhaust port. This allows for a check valve structure to be constructed around the vacuum exhaust port, which both smoothly evacuates and assists in sealing after evacuation. This check valve structure stably maintains the required vacuum level for the vacuum insulation layer over a long period of time, thereby extending the life and durability of the vacuum insulated container. Furthermore, by overlapping the bottom extended bottom plate on the outside of the extended wall of the outer tube so that the tip of the extended bottom plate is in surface contact with the lower part of the extended wall, and joining the tip edge of the extended bottom plate to the extended wall with a fillet weld at a midpoint in the direction in which the extended wall extends, it is possible to absorb the effects of dimensional errors in the bottom extended bottom plate and the extended wall of the outer tube and join them together, thereby increasing the dimensional tolerance of the outer tube that constitutes the outer container and the bottom that closes the bottom side of the outer tube and improving yield.

[0011] The vacuum insulated container of the present invention is characterized in that the outer tube and the bottom are formed from the same metal, and the thickness of the extended bottom plate of the bottom is thinner than the thickness of the extended wall of the outer tube. With this, when evacuating the target space between the inner container and the outer container within the vacuum tank, the extended bottom plate at the bottom bulges outward to promote vacuum evacuation from the target space, and as the vacuum evacuation from the target space progresses, the extended bottom plate can deform so as to come into surface contact with the extended wall more smoothly.

[0012] The vacuum insulated container of the present invention is characterized in that the extended bottom plate is composed of an inclined bottom plate that extends upward and outward, and a downwardly convex, mountain-shaped protrusion is formed connected to the lower end of the inclined bottom plate at the bottom. This increases the rigidity of the inclined bottom plate at the bottom with a protrusion connected to the lower end of the inclined bottom plate, thereby reliably preventing buckling from occurring at the middle point in the direction in which the inclined bottom plate extends when evacuating the vacuum chamber.

[0013] The vacuum insulated container of the present invention is characterized in that the fillet weld is composed of an arc-shaped weld having a notch that forms the vacuum exhaust port, and a sealing weld that is formed locally to close the notch. This allows the vacuum insulation layer to be sealed simply by locally welding the notch without rotating the workpiece in the vacuum chamber, ensuring the required degree of vacuum for the vacuum insulation layer of the vacuum insulated container. Furthermore, this eliminates the need for a process for installing a sealant at the local vacuum exhaust port of the workpiece, thereby improving the efficiency of the manufacturing process.

[0014] The vacuum insulated container of the present invention is characterized in that a vacuum exhaust hole is provided as the vacuum exhaust port, penetrating the inclined bottom plate at a position inside the fillet weld in the overlapping area of the extended wall and the extended bottom plate, and the vacuum exhaust hole is sealed. According to this method, simply by fillet welding the leading edge of the extended bottom plate to the extended wall around the entire circumference and providing a sealant for the vacuum exhaust hole and placing the workpiece in a vacuum tank, it is possible to reliably evacuate the vacuum exhaust hole and reliably seal it, thereby reliably achieving the required degree of vacuum for the vacuum insulation layer of the vacuum insulated container. In addition, the outer tube and bottom that make up the outer container can be integrated in a single fillet welding process, thereby improving the efficiency of the manufacturing process.

[0015] The vacuum insulated container of the present invention is characterized in that the vacuum exhaust hole is sealed with a conductive sealing material. According to this method, by sealing the vacuum exhaust hole in the metal bottom with a conductive sealant, the sealed portion becomes less noticeable, enhancing the integrated appearance of the vacuum insulated container. Furthermore, it becomes possible to perform surface treatment by anodizing after the outer shape of the vacuum insulated container is completed. Furthermore, the vacuum insulated container can be manufactured using a vacuum chamber similar to that used when sealing the vacuum exhaust hole with glass, and the heating capacity of the heater installed in the vacuum chamber can be increased to a degree, thereby enabling the manufacture of a long-life, highly durable vacuum insulated container while suppressing increases in manufacturing costs.

[0016] The method for manufacturing a vacuum insulated container of the present invention uses an outer cylinder having an extension wall around the bottom that extends inward and a bottom portion having an extension bottom plate around the bottom that extends outward, and includes a first step of placing the tip of the extension bottom plate on the bottom of the extension wall from the outside, a second step of fillet welding the tip edge of the extension bottom plate in an arc shape at a midpoint in the direction in which the extension wall extends so as to leave a notch in the extension wall that forms a vacuum exhaust port, and a second step of placing the workpiece in a vacuum chamber, in which the bottomed cylindrical metallic inner container and the outer cylinder are joined. a third step of evacuating the target space between the outer tube and the bottom and the inner container through the path between the extended bottom plate and the extended wall and the notch, and bringing the tip of the extended bottom plate into surface contact with the lower part of the extended wall; and a fourth step of locally fillet welding the notch in the workpiece to close the bottom side of the outer tube with the bottom, thereby forming a cylindrical, metal outer container with a bottom, and providing a vacuum insulation layer between the inner container and the outer container. According to this, by locally locating the notch constituting the vacuum exhaust port near the leading edge of the extended bottom plate and along a portion of the circumference of the bottom, it is possible to seal the vacuum exhaust port without rotating the workpiece in a vacuum chamber where the vacuum level is stable, thereby reliably achieving the required vacuum level for the vacuum insulation layer of the vacuum insulated container. Furthermore, when evacuating the target space between the inner and outer containers in the vacuum chamber, the extended bottom plate at the bottom, which is located around the vacuum exhaust port, expands outward to promote evacuation from the target space. As the evacuation from the target space progresses, the extended bottom plate deforms to make surface contact with the extended wall, allowing evacuation through the notch constituting the vacuum exhaust port. This allows for a check valve structure to be constructed around the vacuum exhaust port, which achieves both smooth evacuation and assists in sealing after evacuation. This check valve structure stably maintains the required vacuum level for the vacuum insulation layer over a long period of time, thereby extending the life and durability of the vacuum insulated container. Furthermore, the vacuum insulation layer can be sealed simply by locally welding the notch without rotating the workpiece in the vacuum chamber, thereby reliably achieving the required degree of vacuum for the vacuum insulation layer of the vacuum insulated container. Furthermore, the process of installing a sealant at the local vacuum exhaust port of the workpiece is unnecessary, thereby improving the efficiency of the manufacturing process. Furthermore, by overlapping the bottom extended bottom plate on the outside of the extended wall of the outer tube so that the tip of the extended bottom plate is in surface contact with the lower part of the extended wall, and fillet welding the tip edge of the extended bottom plate to the extended wall at a midpoint in the extension direction of the extended wall, the effects of dimensional errors in the bottom extended bottom plate and the extended wall of the outer tube can be absorbed during joining, thereby increasing the dimensional tolerance of the outer tube and the bottom portion that closes the bottom side of the outer tube that constitute the outer container, and improving yield.

[0017] The method for manufacturing a vacuum insulated container of the present invention uses an outer cylinder having an extension wall extending inwardly around its lower periphery and a bottom portion having an extension bottom plate extending outwardly around its periphery, and includes a first step of arranging a tip end of the extension bottom plate so as to overlap the lower portion of the extension wall from the outside, a second step of welding the tip end edge of the extension bottom plate to the extension wall around its entire periphery at a midpoint in the direction in which the extension wall extends to form a fillet weld, and a second step of providing a sealant in a vacuum exhaust hole penetrating the extended bottom plate at a position inside the fillet weld in the overlapping region of the extension wall and the extension bottom plate. a second step of placing the workpiece, in which a bottomed cylindrical metallic inner container and the outer container are joined, in a vacuum chamber, and evacuating the target space between the outer container and the bottom and the inner container through the path between the extended bottom plate and the extended wall and the vacuum exhaust hole, and bringing the tip of the extended bottom plate into surface contact with the lower part of the extended wall; and a fourth step of sealing the vacuum exhaust hole with the sealing material to form a bottomed cylindrical metallic outer container and provide a vacuum insulation layer between the inner container and the outer container. According to this configuration, by locally arranging the vacuum exhaust holes constituting the vacuum exhaust port near the leading edge of the extended bottom plate and along a portion of the circumference of the bottom, it is possible to seal the vacuum exhaust port without rotating the workpiece in a vacuum chamber where the vacuum level is stable, thereby reliably achieving the required vacuum level for the vacuum insulation layer of the vacuum insulated container. Furthermore, when evacuating the target space between the inner and outer containers in the vacuum chamber, the extended bottom plate at the bottom, which is located around the vacuum exhaust port, expands outward to promote evacuation from the target space. As the evacuation from the target space progresses, the extended bottom plate deforms to make surface contact with the extended wall, allowing evacuation through the vacuum exhaust holes constituting the vacuum exhaust port. This allows for a check valve structure to be constructed around the vacuum exhaust port, which achieves both smooth evacuation and assists in sealing after evacuation. This check valve structure stably maintains the required vacuum level for the vacuum insulation layer over a long period of time, thereby extending the life and durability of the vacuum insulated container. Furthermore, simply by fillet-welding the leading edge of the extended bottom plate to the extended wall around its entire circumference and placing a workpiece with a sealant in the vacuum exhaust hole in a vacuum chamber, reliable evacuation through the vacuum exhaust hole and reliable sealing can be achieved, thereby reliably achieving the required vacuum level for the vacuum insulation layer of the vacuum insulated container. Furthermore, the outer tube and bottom portion constituting the outer container can be integrated in a single fillet welding process, thereby improving the efficiency of the manufacturing process. Furthermore, by overlapping the bottom extended bottom plate on the outside of the extended wall of the outer tube so that the leading edge of the extended bottom plate is in surface contact with the lower part of the extended wall, and fillet-welding the leading edge of the extended bottom plate to the extended wall at a midpoint in the direction of extension of the extended wall, the effects of dimensional errors in the bottom extended bottom plate and the extended wall of the outer tube can be absorbed during joining, thereby increasing the dimensional tolerance of the outer tube constituting the outer container and the bottom portion that closes the bottom side of the outer tube, and improving yield. [Effects of the Invention]

[0018] According to the present invention, the required degree of vacuum in the vacuum insulation layer of the vacuum insulated container can be reliably obtained, and the required degree of vacuum in the vacuum insulation layer can be stably maintained over a long period of time, thereby extending the life and improving the durability of the vacuum insulated container. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a vertical cross-sectional view showing a vacuum insulated container according to a first embodiment of the present invention. [Figure 2] (a) is an enlarged view of part A in Figure 1, and (b) is an enlarged view of part B in Figure 1. [Figure 3] FIG. 2(a) is a bottom view showing the vacuum insulated container of the first embodiment, and FIG. 2(b) is an enlarged view of part C in FIG. [Figure 4] (a) is a partial cross-sectional view of a workpiece in which the tip of the bottom extended bottom plate is placed on the lower part of the extended wall of the outer tube from the outside, and (b) is a partial cross-sectional view of a workpiece that has been fillet welded leaving a notch. [Figure 5] 1 is a schematic diagram of a state in which a workpiece of the vacuum insulated container of the first embodiment is placed in a vacuum chamber. [Figure 6] FIG. 10 is a cross-sectional explanatory view illustrating deformation of the extended bottom plate of the workpiece of the first embodiment during evacuation. [Figure 7] FIG. 4 is a vertical cross-sectional view showing a vacuum insulated container according to a second embodiment of the present invention. [Figure 8] (a) is an enlarged view of part D in Figure 7, and (b) is an enlarged view of part E in Figure 7. [Figure 9] FIG. 10(a) is a bottom view showing a vacuum insulated container of a second embodiment, and FIG. 10(b) is an enlarged view of part F in FIG. [Figure 10] (a) is a partial cross-sectional view of a workpiece in which the tip of the bottom extended bottom plate is placed on the lower part of the extended wall of the outer tube from the outside, and (b) is a partial cross-sectional view of a workpiece in which a fillet weld is formed and a conductive sealant is provided in the vacuum exhaust hole. [Figure 11] FIG. 10 is a schematic diagram of a state in which a workpiece of the vacuum insulated container of the second embodiment is placed in a vacuum chamber. [Figure 12] 10 is a cross-sectional view illustrating deformation of the extended bottom plate of the workpiece of the second embodiment during evacuation. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0020] [Vacuum insulated container of the first embodiment and its manufacturing method] 1 to 3, a vacuum insulated container 1 according to a first embodiment of the present invention has a cylindrical bottomed inner container 2 made of a metal such as stainless steel and a cylindrical bottomed outer container 3 made of a metal such as stainless steel, with a space provided between the inner container 2 and the outer container 3, which serves as a vacuum insulation layer 4. The vacuum insulation layer 4 in the illustrated example is a vacuum insulation layer in which the space between the inner container 2 and the outer container 3 is a hollow vacuum or reduced pressure state, but it is also suitable as a vacuum insulation layer in which the space between the inner container 2 and the outer container 3 is filled with a thermal insulating material and the space is placed in a vacuum or reduced pressure state. The vacuum insulated container 1 in the illustrated example is a can holder.

[0021] The inner container 2 is made of a thin metal plate and has a cylindrical shape with a bottom, and is composed of a peripheral wall 21 and a bottom 22. The peripheral wall 21 and the bottom 22 are integrally formed from the same metal material. A recess 221 is provided in the approximate center of the bottom 22 so as to protrude in a dome shape toward the mouth of the inner container 2.

[0022] The outer container 3 is composed of a substantially cylindrical outer tube 31 that penetrates vertically, and a bottom portion 32 that closes the bottom side of the outer tube 31, and the outer tube 31 and bottom portion 32 are each integrally formed from a thin metal plate material. The mouth side of the outer tube 31 of the outer container 3 is provided with a bent portion 311 that is bent inward into a substantially L-shape in cross section, and the tip of the bent portion 311 is positioned so as to overlap the outside of the mouth side tip of the peripheral side wall 21 of the inner container 2, and the mouth side tip edge of the peripheral side wall 21 and the tip edge of the bent portion 311 are circumferentially welded at a weld portion 7.

[0023] A curved portion 312 that curves inward is provided around the lower portion of the outer cylinder 31, and an extending wall 313 is provided below the curved portion 312. The extending wall 313 is provided around the periphery so as to extend inward, and in this embodiment, the extending wall 313 is an inclined wall that is provided around the periphery so as to extend downward and inward. The angle of the extending wall 313 with respect to the vertical direction is preferably 15 to 90 degrees, and more preferably 60 to 90 degrees, and the length of the extending wall 313 is preferably 2.0 mm or more, and more preferably 4.0 mm or more.

[0024] The bottom 32 is generally disk-shaped in bottom view and has an extended bottom plate 321 extending outward. In this embodiment, the extended bottom plate 321 is an inclined bottom plate that is circumferentially arranged so as to extend upward and outward. When the vacuum insulation layer 4 is provided, the extended bottom plate 321 is provided at an angle that follows the extended wall 313 of the outer cylinder 31. The inclination angle of the extended bottom plate 321 relative to the extended wall 313 is preferably 0 to 12 degrees, and more preferably 0 to 4 degrees. The upper end of the extended bottom plate 321 is provided overlapping the lower part of the extended wall 313 from the outside so as to be in surface contact with the lower part of the extended wall 313. The overlap length of the overlapping region between the upper end of the extended bottom plate 321 and the extended wall 313 in the direction of extension of the extended wall 313 is, for example, approximately 1 / 4 to 3 / 4, and more preferably approximately 1 / 3 to 2 / 3 of the length of the extended wall 313.

[0025] A series of downwardly convex, mountain-shaped ridges 322 are formed on the lower end of the extended bottom plate 321, which is made up of an inclined bottom plate of the bottom portion 32, and the ridges 322 are formed circumferentially when viewed from the bottom of the vacuum insulated container 1. The area surrounded by the ridges 322 forms a recess 323 that is concave upward and dish-shaped. A getter 9 is provided in the vacuum insulation layer 4 between the recess 323 and the recess 221.

[0026] Although the outer cylinder 31 and the bottom 32 can be formed from different metal materials, it is preferable to form them from the same metal material, and furthermore, when the outer cylinder 31 and the bottom 32 are formed from the same metal, it is more preferable to form the extended bottom plate 321 of the bottom 32 thinner than the extended wall 313 of the outer cylinder 31. By forming the outer cylinder 31 and the bottom 32 from the same metal and forming the extended bottom plate 321 thinner than the extended wall 313, when performing vacuum evacuation, the extended bottom plate 321 bulges outward to promote vacuum evacuation from the target space, and as the vacuum evacuation from the target space progresses, it becomes possible to more smoothly perform the action of the extended bottom plate 321 deforming so as to come into surface contact with the extended wall 313.

[0027] The leading edge of the extended bottom plate 321, which is superimposed on the outside of the extended wall 313, is joined to the extended wall 313 at a midpoint in the direction in which the extended wall 313 extends by a fillet weld 5. A vacuum exhaust port 6 is provided near the leading edge of the extended bottom plate 321, and the vacuum exhaust port 6 is locally arranged in a portion of the circumferential direction of the bottom 32. In the first embodiment, the vacuum exhaust port 6 is configured by a notch 61 in the arc-shaped weld 51 that constitutes the fillet weld 5.

[0028] The fillet weld 5 is composed of an arc-shaped weld 51 having a notch 61 that forms the vacuum exhaust port 6, and a sealing weld 52 that is formed locally to block the notch 61, and the sealing weld 52 seals the notch 61 that is the vacuum exhaust port 6.

[0029] When manufacturing the vacuum insulated container 1 of the first embodiment, an outer tube 31 having an extending wall 313 slanting inward and extending downward, and a bottom 32 having an extending bottom plate 321 slanting outward and extending upward, are used, and the tip of the extending bottom plate 321 of the bottom plate 32 is placed on the bottom of the extending wall 313 of the outer tube 31 from the outside to form the work W1 of the outer container 3 (see Figure 4(a)).

[0030] Furthermore, as shown in Figure 4(b), the tip edge of the extended bottom plate 321 is fillet welded in an arc shape at a midpoint in the extension direction of the extended wall 313 so as to leave a notch 61 that forms the vacuum exhaust port 6 in the extended wall 313, thereby forming an arc-shaped weld 51, and the bottomed, cylindrical metal inner container 2 placed inside the outer tube 31 is circumferentially welded to the outer tube 31 at the mouth side by a weld 7 to form a workpiece W2 in which the inner container 2, outer tube 31, and bottom 32 are joined together.

[0031] The workpiece W2 is placed inside a vacuum chamber 100 shown in Fig. 5. The vacuum chamber 100 includes a vacuum pump 101, a heater 102, a glass window 103 that transmits laser light, and a mounting table 104 on which the workpiece W2 is placed, and a laser welder 105 is installed outside the glass window 103. The workpiece W2 is placed on the mounting table 104 so that the notch 61 is positioned at the laser welding position of the laser welder 102 that irradiates the interior of the vacuum chamber 100 with laser light through the glass window 103, and in the illustrated example, the workpiece W2 is placed on the mounting table 104 with the bottom side facing up.

[0032] Then, while the inside of the vacuum chamber 100 is heated by the heater 102, the vacuum pump 101 reduces the pressure, and the target space between the outer cylinder 31 and bottom 32 of the work W2 and the inner container 2 is evacuated via the space between the extended bottom plate 321 of the bottom 31 and the extended wall 313 of the outer cylinder 31 and the notch 61, thereby forming the work W3 (see FIG. 6). At this time, the extended bottom plate 321 of the bottom 32 bulges outward away from the extended wall 313 of the outer cylinder 31 to promote evacuation from the target space (see the thick dotted arrow in FIG. 6), and as evacuation from the target space progresses, the extended bottom plate 321 deforms so as to come into surface contact with the extended wall 313 (see the thick dotted arrow in FIG. 6).

[0033] Then, inside the vacuum chamber 100, a laser welding machine 105 is used to locally fillet weld the notch 61 of the workpiece W3 to close it, forming a sealing weld 52, and the bottom side of the outer tube 31 is closed with the bottom 32 to form a cylindrical, bottomed, metallic outer container 3, and a vacuum insulation layer 4 is provided between the inner container 2 and the outer container 3, thereby obtaining the vacuum insulated container 1 of the first embodiment (see Figure 2).

[0034] According to the first embodiment, by arranging the vacuum exhaust port 6 near the leading edge of the extended bottom plate 321 of the bottom 32 and locally on a portion of the circumference of the bottom 32, it becomes possible to seal the vacuum exhaust port 6 without rotating the workpiece W3 inside the vacuum chamber 100, where the degree of vacuum is stable, and the desired degree of vacuum can be reliably obtained for the vacuum insulation layer 4 of the vacuum insulated container 1. Furthermore, when evacuating the target space between the inner container 2 and the outer container 3 inside the vacuum chamber 100, the extended bottom plate 321 of the bottom 32, which is located in the vicinity of the vacuum exhaust port 6, bulges outward to promote evacuation from the target space, and as the evacuation from the target space progresses, the extended bottom plate 321 deforms so as to come into surface contact with the extended wall 313, thereby enabling evacuation from the vacuum exhaust port 6. This makes it possible to construct a check valve structure around the vacuum exhaust port 6 that achieves both smooth evacuation and assists in sealing after evacuation. This check valve structure makes it possible to stably maintain the required degree of vacuum in the vacuum insulation layer 4 for a long period of time, thereby extending the life and improving the durability of the vacuum insulation container 1.

[0035] Furthermore, by overlapping the extended bottom plate 321 of the bottom 32 on the outside of the extended wall 313 of the outer tube 31 so that the upper end of the extended bottom plate 321 of the bottom 32 is in surface contact with the lower part of the extended wall 313 of the outer tube 31, and joining the tip edge of the extended bottom plate 321 to the extended wall 313 with a fillet weld 5 at a midpoint in the extension direction of the extended wall 313, it is possible to absorb the effects of dimensional errors in the extended bottom plate 321 of the bottom 32 and the extended wall 313 of the outer tube 31 and join them, thereby increasing the dimensional tolerance of the outer tube 31 that constitutes the outer container 3 and the bottom 32 that closes the bottom side of the outer tube 31 and improving yield.

[0036] Furthermore, by forming the outer cylinder 31 and the bottom 32 from the same metal and forming the extended bottom plate 321 of the bottom 32 thinner than the extended wall 313 of the outer cylinder 31, when evacuating the target space between the inner container 2 and the outer container 3 inside the vacuum chamber 100, the extended bottom plate 321 of the bottom 32 expands outward to promote evacuation from the target space, and as the evacuation from the target space progresses, the extended bottom plate 321 can be deformed more smoothly to come into surface contact with the extended wall 313.

[0037] Furthermore, by forming downwardly convex, angle-shaped protrusions 322 connected to the lower end of the extended bottom plate 321, which is composed of the inclined bottom plate of the bottom 32, the rigidity of the extended bottom plate 321 of the bottom 32 is increased, and buckling can be reliably prevented from occurring at the middle point in the direction in which the extended bottom plate 321 extends when evacuating the vacuum chamber 100.

[0038] Furthermore, by configuring the fillet weld 5 from an arc-shaped weld 51 having a notch 61 that forms the vacuum exhaust port 6 and a sealing weld 52 that is locally formed to close the notch 61, the vacuum insulation layer 4 can be sealed simply by performing local welding to close the notch 61 without rotating the workpiece W3 inside the vacuum tank 100, thereby reliably achieving the degree of vacuum required for the vacuum insulation layer 4 of the vacuum insulated container 1. Furthermore, the process of installing a sealing material at the local vacuum exhaust port 6 of the workpiece W3 is no longer necessary, making the manufacturing process more efficient.

[0039] [Vacuum insulated container of second embodiment and manufacturing method thereof] 7 to 9, a vacuum insulated container 1a according to a second embodiment of the present invention includes a cylindrical inner container 2a with a bottom and made of a metal such as stainless steel, and a cylindrical outer container 3a with a bottom and made of a metal such as stainless steel. A space is provided between the inner container 2a and the outer container 3a, and this space serves as a vacuum insulation layer 4a. The vacuum insulation layer 4a is a vacuum insulation layer in which the space between the inner container 2a and the outer container 3a is a hollow space that is in a vacuum or reduced pressure state. However, the vacuum insulation layer 4a may also be a vacuum insulation layer in which the space between the inner container 2a and the outer container 3a is filled with a thermal insulating material and the space is in a vacuum or reduced pressure state. The vacuum insulated container 1a shown in the figures is also a can holder, as in the first embodiment.

[0040] The inner container 2a is the same as the inner container 2 in the first embodiment, and is composed of a peripheral side wall 21a and a bottom 22a, and is entirely made of a thin metal plate. A recess 221a is provided in the approximate center of the bottom 22a, projecting in a dome shape toward the mouth side of the inner container 2a.

[0041] The outer container 3a is composed of a substantially cylindrical outer tube 31a that penetrates vertically and a bottom portion 32a that closes the bottom side of the outer tube 31a, and the outer tube 31a and bottom portion 32a are each integrally formed from a thin metal plate. The outer tube 31a is the same as the outer tube 31 in the first embodiment, and is arranged so that the tip of the bent portion 311a of the outer tube 31a overlaps the outside of the tip of the mouth side of the peripheral side wall 21a of the inner container 2a, and the mouth side tip edge of the peripheral side wall 21a and the tip edge of the bent portion 311a are circumferentially welded at weld portion 7a.

[0042] A curved portion 312a that curves inward is provided around the lower portion of the outer cylinder 31a, and an extending wall 313a is provided below the curved portion 312a. The extending wall 313a is provided so as to extend inward, and in this embodiment, the extending wall 313a is an inclined wall that is provided so as to extend downward and inward. The angle of the extending wall 313a with respect to the vertical direction should be set to the same angle as the inclined wall 313 in the first embodiment with respect to the vertical direction, and the length of the extending wall 313a should be longer than in the first embodiment by the diameter of the vacuum exhaust hole 62a (described later), preferably 4.0 mm or more, and more preferably 6.0 mm or more.

[0043] The bottom 32a is generally disk-shaped in bottom view, and has an extended bottom plate 321a extending outward. In this embodiment, the extended bottom plate 321a is an inclined bottom plate that is provided around the periphery so as to extend upward and outward. When the vacuum insulation layer 4a is provided, the extended bottom plate 321a is provided at an angle that follows the extended wall 313a of the outer cylinder 31a, and the inclination angle of the extended bottom plate 321a relative to the extended wall 313a is preferably 0 to 7 degrees, more preferably 0 to 3 degrees. The upper end of the extended bottom plate 321a is provided overlapping the lower part of the extended wall 313a from the outside so as to be in surface contact with the lower part of the extended wall 313a. The overlapping area between the upper end of the extended bottom plate 321a and the extended wall 313a can be set appropriately so that the inclined wall 313a overlaps the entire vacuum exhaust hole 62a, but the overlapping length in the extension direction of the extended wall 313a in the overlapping area is preferably, for example, about 1 / 4 to 3 / 4 of the length of the extended wall 313a, more preferably about 1 / 3 to 2 / 3.

[0044] The lower end of the extended bottom plate 321a, which is made up of an inclined bottom plate of the bottom portion 32a, is formed with a series of downwardly convex, mountain-shaped protrusions 322a, which are formed circumferentially when viewed from the bottom of the vacuum insulated container 1a. The area surrounded by the protrusions 322a forms a dish-shaped recess 323a that is concave upward. A getter 9a is provided in the vacuum insulation layer 4a between the recess 323a and the recess 221a.

[0045] Although the outer cylinder 31a and the bottom 32a can be formed from different metal materials, it is preferable to form them from the same metal material, and further, when the outer cylinder 31a and the bottom 32a are formed from the same metal, it is more preferable to form the extended bottom plate 321a of the bottom 32a thinner than the extended wall 313a of the outer cylinder 31a. By forming the outer cylinder 31a and the bottom 32a from the same metal and forming the extended bottom plate 321a thinner than the extended wall 313a, when performing vacuum evacuation, the extended bottom plate 321a bulges outward to promote vacuum evacuation from the target space, and as the vacuum evacuation from the target space progresses, the extended bottom plate 321a can deform more smoothly so as to come into surface contact with the extended wall 313a.

[0046] The leading edge of the extended bottom plate 321a, which is placed on the outside of the extended wall 313a, is joined to the extended wall 313a at a fillet weld 5a at a midpoint in the extension direction of the extended wall 313a. The fillet weld 5a in the second embodiment is continuously formed around the circumference of the vacuum insulated container 1a when viewed from the bottom.

[0047] A vacuum exhaust port 6a is provided near the leading edge of the extended bottom plate 321a, and the vacuum exhaust port 6a is locally arranged in a portion of the circumferential direction of the bottom portion 32a. In the second embodiment, a vacuum exhaust hole 62a is provided as the vacuum exhaust port 6a, penetrating the extended bottom plate 321a at a position inside the fillet weld 5a in the overlapping region of the extended wall 313a and the extended bottom plate 321a. The vacuum exhaust hole 62a is sealed with a sealing material, and in the second embodiment, is sealed with a conductive sealing material 8a, such as a conductive metal material like a brazing filler metal, which melts during vacuum evacuation in a heated state.

[0048] When manufacturing the vacuum insulated container 1a of the second embodiment, an outer tube 31a having an extending wall 313a extending downward and sloping inward and a bottom 32a having an extending bottom plate 321a extending upward and sloping outward are used, and the tip of the extending bottom plate 321a of the bottom plate 32a is placed on the bottom of the extending wall 313a of the outer tube 31a from the outside to form a work W4 of the outer container 3a (see Figure 10(a)).

[0049] Furthermore, as shown in Figure 10(b), the tip edge of the extended bottom plate 321a is welded to the extended wall 313a around the entire circumference at a midpoint in the extension direction of the extended wall 313a to form a fillet weld 5a, and a conductive sealing material 8a is provided in a vacuum exhaust hole 62a that penetrates the extended bottom plate 321a at a position bottomward of the fillet weld 5a in the overlapping region of the extended wall 313a and the extended bottom plate 321a, and the bottomed, cylindrical, metallic inner container 2a placed inside the outer tube 31a is circumferentially welded to the outer tube 31a at a weld 7a on the mouth side to form a workpiece W5 in which the inner container 2a, outer tube 31a, and bottom 32a are joined (see Figure 11).

[0050] The workpiece W5 is placed inside a vacuum chamber 100a shown in Fig. 11. The vacuum chamber 100a includes a vacuum pump 101a, a heater 102a, and a mounting table 104a on which the workpiece W5 is placed. The workpiece W5 is placed on the mounting table 104a with the bottom side facing up, for example.

[0051] Then, while the inside of the vacuum chamber 100a is heated by the heater 102a, the vacuum pump 101a reduces the pressure, and the target space between the outer cylinder 31a and bottom 32a of the workpiece W5 and the inner container 2a is evacuated via the space between the extended bottom plate 321a of the bottom 31a and the extended wall 313a of the outer cylinder 31a and through the vacuum exhaust holes 62a (see FIG. 12). At this time, the extended bottom plate 321a of the bottom 32a bulges outward away from the extended wall 313a of the outer cylinder 31a, facilitating evacuation from the target space (see the thick dotted arrow in FIG. 12). As evacuation from the target space progresses, the extended bottom plate 321a deforms so as to come into surface contact with the extended wall 313a (see the thick dotted arrow in FIG. 12).

[0052] By proceeding with evacuation while heating with the heater 102a, the conductive sealant 8a provided in the evacuation hole 62a melts and flows into the evacuation hole 62a, filling it in. Thereafter, by stopping the heating of the heater 102a and evacuation, the evacuation hole 62a is sealed with the solidified conductive sealant 8a, forming a cylindrical, metal outer container 3a with a bottom, and providing a vacuum insulation layer 4a between the inner container 2a and the outer container 3a, thereby obtaining the vacuum insulated container 1a of the second embodiment (see FIG. 8).

[0053] According to the second embodiment, the leading edge of the extended bottom plate 321a is fillet welded to the extended wall 313a around the entire circumference, and the workpiece W6, which has the conductive sealant 8a provided in the vacuum exhaust hole 62a, is simply placed in the vacuum chamber 100a. This ensures reliable evacuation and sealing through the vacuum exhaust hole 62a, and ensures the required degree of vacuum in the vacuum insulation layer 4a of the vacuum insulated container 1a. Furthermore, the outer cylinder 31a and the bottom 32a that constitute the outer container 3a can be integrated in a single fillet welding process, thereby improving the efficiency of the manufacturing process.

[0054] Furthermore, by sealing the vacuum exhaust hole 62a in the metal bottom 32a with a conductive sealant 8a such as a conductive metal material, the sealed portion becomes less noticeable, enhancing the integrated appearance of the vacuum insulated container 1a. Furthermore, after the outer shape of the vacuum insulated container 1a is completed, a surface treatment by anodizing can be performed. Furthermore, the vacuum insulated container 1a can be manufactured using the same vacuum chamber 100a as when the vacuum exhaust hole is sealed with glass, and the heating capacity of the heater 102a installed in the vacuum chamber 100a can be increased to a degree. This allows the manufacture of a vacuum insulated container 1a with a long life and high durability while suppressing increases in manufacturing costs.

[0055] Furthermore, the second embodiment can obtain the same effects as the first embodiment due to the configuration corresponding to the first embodiment.

[0056] [Scope of the invention disclosed herein] The inventions disclosed in this specification include, in addition to the inventions, embodiments, and modifications thereof listed as inventions, those specified by changing partial contents of these to other contents disclosed in this specification, those specified by adding other contents disclosed in this specification to these contents, or those specified by deleting partial contents of these to the extent that partial effects are obtained and creating a generic concept. The inventions disclosed in this specification also include the following modifications and additions.

[0057] For example, the type of vacuum insulated container of the present invention is not limited to the can holder of the first and second embodiments, but can be any appropriate vacuum insulated container, and is suitable for use as a mug, soup cup, lunch jar, portable thermos, or tabletop thermos. Furthermore, the closure structure of the mouth side of the bottomed cylindrical metallic inner container and bottomed cylindrical metallic outer container in the vacuum insulated container of the present invention is not limited to the closure structure of the first and second embodiments, but can be any appropriate structure. Furthermore, as a modification of the second embodiment, a non-conductive sealing material can be used as the sealing material instead of the conductive sealing material 8a. [Industrial Applicability]

[0058] The present invention can be used for vacuum insulated containers such as can holders, mugs, soup cups, lunch jars, portable thermoses, and tabletop thermoses. [Explanation of symbols]

[0059] REFERENCE SIGNS LIST 1, 1a...vacuum insulated container 2, 2a...inner container 21, 21a...circumferential side wall 22, 22a...bottom 221, 221a...recess 3, 3a...outer container 31, 31a...outer cylinder 311, 311a...bent portion 312, 312a...curved portion 313, 313a...extended wall 32, 32a...bottom 321, 321a...extended bottom plate 322, 322a...protrusion 323, 323a...recess 4, 4a...vacuum insulating layer 5, 5a...fillet weld 51...arc-shaped weld 52...seal weld 6, 6a...vacuum exhaust port 61...notch 62a...vacuum exhaust hole 7, 7a...weld 8a...conductive sealing material 9, 9a...getter 100, 100a...vacuum chamber 101, 101a... Vacuum pump 102, 102a... Heater 103... Glass window 104, 104a... Placement table 105... Laser welding machine W1, W2, W3, W4, W5... Workpiece

Claims

1. A vacuum insulation layer is provided between a cylindrical metal inner container with a bottom and a cylindrical metal outer container with a bottom, the outer container is composed of an outer cylinder and a bottom portion that closes the bottom side of the outer cylinder, An extension wall extending inward is provided around the lower part of the outer cylinder, An extension bottom plate extending outward is provided around the bottom portion, The tip end of the extended bottom plate is overlapped from the outside so as to be in surface contact with the lower part of the extended wall, a tip edge of the extended bottom plate is joined to the extended wall by a fillet weld at an intermediate position in the extension direction of the extended wall; A vacuum insulated container characterized in that vacuum exhaust ports provided near the leading edge of the extended bottom plate and locally arranged in a portion of the circumferential direction of the bottom are sealed.

2. The outer cylinder and the bottom are formed of the same metal, 2. The vacuum insulated container according to claim 1, wherein the thickness of the extended bottom plate at the bottom is thinner than the thickness of the extended wall of the outer cylinder.

3. The extending bottom plate is configured as an inclined bottom plate that extends upward and outward, 3. The vacuum insulated container according to claim 2, wherein a downwardly convex, angle-shaped protrusion is formed on the bottom portion of the inclined bottom plate so as to be continuous with the lower end of the inclined bottom plate.

4. 4. A vacuum insulated container according to claim 1, wherein the fillet weld is composed of an arc-shaped weld having a notch that forms the vacuum exhaust port, and a sealing weld that is locally formed to close the notch.

5. a vacuum exhaust hole penetrating the inclined bottom plate at a position inside the fillet weld in an overlapping region between the extension wall and the extension bottom plate, the vacuum exhaust hole serving as the vacuum exhaust port; 4. The vacuum insulated container according to claim 1, wherein the vacuum exhaust hole is sealed.

6. 6. The vacuum insulated container according to claim 5, wherein the vacuum exhaust hole is sealed with a conductive sealant.

7. a first step of using an outer cylinder having an inwardly extending extension wall disposed around the lower portion thereof and a bottom portion having an outwardly extending extension bottom plate disposed around the lower portion thereof, and placing a tip end of the extension bottom plate on the lower portion of the extension wall from the outside; a second step of fillet-welding the tip edge of the extended bottom plate in an arc shape at a midpoint in the extension direction of the extended wall so as to leave a notch in the extended wall that forms a vacuum exhaust port; a third step of placing the workpiece, in which the outer cylinder is joined to a cylindrical, metal inner container with a bottom, in a vacuum chamber, evacuating a target space between the outer cylinder and the bottom and the inner container through a path between the extended bottom plate and the extended wall and through the notch, and bringing a tip end of the extended bottom plate into surface contact with a lower part of the extended wall; A method for manufacturing a vacuum insulated container, characterized by including a fourth step of locally fillet welding the notch in the workpiece to close it, thereby closing the bottom side of the outer tube with the bottom to form a cylindrical, bottomed metal outer container, and providing a vacuum insulation layer between the inner container and the outer container.

8. a first step of using an outer cylinder having an inwardly extending extension wall disposed around the lower portion thereof and a bottom portion having an outwardly extending extension bottom plate disposed around the lower portion thereof, and placing a tip end of the extension bottom plate on the lower portion of the extension wall from the outside; a second step of welding a tip edge of the extended bottom plate to the extended wall around the entire circumference at a midpoint in the extension direction of the extended wall to form a fillet weld, and providing a sealant in a vacuum exhaust hole penetrating the extended bottom plate at a position inside the fillet weld in an overlapping region of the extended wall and the extended bottom plate; a third step of placing the workpiece, which is a cylindrical workpiece having a bottom and a metallic inner container joined to the outer container, in a vacuum chamber, evacuating the target space between the outer container and the bottom and the inner container through the space between the extended bottom plate and the extended wall and the vacuum exhaust hole, and bringing the tip of the extended bottom plate into surface contact with the lower part of the extended wall; A method for manufacturing a vacuum insulated container, characterized by including a fourth step of sealing the vacuum exhaust hole with the sealing material to form a cylindrical, bottomed, metallic outer container, and providing a vacuum insulation layer between the inner container and the outer container.

Images