JP2013154367A - Method for manufacturing vacuum structure and vacuum structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a vacuum structure and a vacuum structure, which can attain the reduction of the number of processes, and at the same time, can improve corrosion resistance, and can manufacture the vacuum structure having light weight and excellent in strength.SOLUTION: When manufacturing a vacuum structure in which an inner container 72 and an outer container 73 are equipped and a vacuum space 74 is formed in between them, a welding process of welding a bottom portion 80 as a member to constitute the vacuum structure to a container body 70, and a vacuuming process of forming the vacuum space 74 are performed simultaneously. The container body 70 and the bottom portion 80 are composed of the same material, and functions as a vacuum holding portion for holding a vacuum state of the vacuum space 74, by being welded to the container body 70 so as to seal the vacuum space 74. Thereby, the reduction of the number of processes can be attained, and the vacuum structure having improved corrosion resistance and light weight and excellent in strength can be manufactured.

Description

  The present invention relates to a method for manufacturing a vacuum structure in which a vacuum space is formed, and a vacuum structure.

  When manufacturing a vacuum structure in which a vacuum space is formed between an inner container such as a thermos bottle and an outer container, after the structure is formed, the space between the inner container and the outer container is evacuated. , Exhaust holes connected to the space are formed, and air in the space is extracted. The exhaust holes are sealed with a brazing material (see, for example, Patent Documents 1 and 2).

Japanese Patent Laid-Open No. 10-328042 JP 2009-269047 A

  However, in the above-described method, after the structure is formed, the space is evacuated and the exhaust hole is sealed. Therefore, in addition to the structure forming step, the vacuum space forming step and the exhaust hole are sealed. A process was needed and the number of processes was increasing. In addition, since a brazing material is required for sealing, an interface is formed between the brazing material and the material of the structure, and the corrosion resistance is not sufficient. Further, in order to seal with the brazing material, the outer container needs to have a corresponding thickness, and it is difficult to reduce the weight and the strength tends to be low.

  An object of the present invention is to provide a vacuum structure manufacturing method and a vacuum structure that can reduce the number of steps, improve corrosion resistance, and can manufacture a vacuum structure that is lightweight and excellent in strength.

  <1> A manufacturing method of a vacuum structure including an inner container and an outer container, in which a vacuum space is formed, a welding step of welding members constituting the vacuum structure, and the vacuum space The vacuum structure manufacturing method is characterized in that the vacuuming step for forming the film is performed at the same time.

  <2> The method for manufacturing a vacuum structure according to <1>, wherein the welding is performed using a material of a member constituting the vacuum structure.

  <3> The method for producing a vacuum structure according to <1> or <2>, wherein nitrogen gas is applied while irradiating a beam to a region to be welded.

  <4> The method for producing a vacuum structure according to any one of <1> to <3>, wherein the region to be welded is irradiated with a beam under a relatively high temperature condition.

  <5> The method for producing a vacuum structure according to any one of <1> to <4>, wherein a beam is irradiated to a region to be welded under a vacuum condition.

  <6> A container body including an inner container and an outer container, in which a vacuum space is formed, and made of the same material as the container body, and welded to the container body so as to seal the vacuum space And a vacuum holding unit that holds a vacuum state of the vacuum space.

  <7> A container body including an inner container and an outer container, in which a vacuum space is formed, and made of the same material as the container body, is fitted into the container body and seals the vacuum space A vacuum holding portion that is welded to the container main body to maintain a vacuum state of the vacuum space, and a welding metal portion that is stored in a direction different from a fitting direction of the vacuum holding portion. It is a structure.

  <8> The weld metal portion is formed so that the deepest position is shallower than the surface of the container body on the side of the vacuum space on the basis of the surface of the container body opposite to the vacuum space side. In addition, the vacuum structure according to <6> or <7> is formed so that the width of the shallowest position is maximized.

  <9> The container main body and the vacuum holding unit are formed of a stainless steel material, and at least the surface on the vacuum space side has a phase having a higher nitrogen concentration than the inside thereof. It is a vacuum structure.

  According to the method for manufacturing a vacuum structure of the present invention, the welding process and the vacuuming process are simultaneously performed, so that the number of processes can be reduced, the corrosion resistance is improved, and the vacuum structure that is lightweight and excellent in strength is manufactured. be able to.

  According to the vacuum structure of the present invention, the vacuum holding part made of the same material as the container main body is welded to the container main body so as to seal the vacuum space, so that the corrosion resistance is improved and the light weight is excellent in strength. It can be.

FIG. 1 is a diagram illustrating a welding apparatus that performs welding on a container of a vacuum structure according to an embodiment of the present invention. FIG. 2 is an enlarged view of a portion I in FIG. FIG. 3 is a view showing a vacuum structure before welding according to the present invention, in which the left side is a front view and the right side is a longitudinal sectional view. FIG. 4 is an enlarged view of a portion II in FIG. FIG. 5 is an enlarged cross-sectional view of a main part of one embodiment of a region to be welded of the vacuum structure of the present invention, where (a) is a view before welding and (b) is a view showing after welding. FIG. 6 is an enlarged cross-sectional view of the main part of another embodiment of the welding region of the vacuum structure of the present invention. FIG. 7 is an enlarged cross-sectional view of an essential part of another embodiment of the welded region of the vacuum structure of the present invention.

  Embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a view showing a welding apparatus for performing welding on a container of a vacuum structure according to the present invention, and FIG. 2 is an enlarged view of a portion I thereof. FIG. 3 is a view showing a vacuum structure before welding according to the present invention, the left side is a front view, the right side is a longitudinal sectional view, and FIG. 4 is an enlarged view of the II part. FIG. 5 is an enlarged cross-sectional view of a main part of one embodiment of a region to be welded of the vacuum structure of the present invention, where (a) is a view before welding and (b) is a view showing after welding. In the description, the structure before the vacuum space is formed may be referred to as a vacuum structure for convenience of description.

  As shown in FIG. 1, the welding apparatus 1 mainly includes an apparatus main body 10, a turntable 20, a drive unit 30, and an auxiliary unit 40. Further, as a welding object by the welding apparatus 1, a vacuum structure in which a space is formed between the inner container and the outer container is an object. In FIG. 1, a thermos bottle 50 is used as an example. In addition, about the thermos 50, in FIG.1 and FIG.2, the longitudinal cross-sectional view is shown on the left side, and the front view is shown on the right side for the convenience of an understanding.

  The apparatus main body 10 includes a beam irradiator 11 and a mounting table 12 on which the beam irradiator 11 is installed. As shown particularly in FIG. 2, the beam irradiator 11 has a beam irradiation part 11a at the tip in the horizontal direction, and the beam irradiation part 11a has a pointed spindle shape toward the welding object, The beam is focused. The beam applied to the welding object may be a laser beam or an electron beam. If the thickness of the welding object is 2 mm or more, a stronger electron beam is preferable, but if it is thinner than that, a laser beam is preferable. In the example of FIG. 1, since the welding object is the thermos 50, it is preferable to reduce the thickness from the viewpoint of weight reduction, and therefore, a laser beam is irradiated.

  A nitrogen gas injection unit 13 is provided on the rear upper side of the beam irradiation unit 11a. Nitrogen gas injected into the laser irradiation unit 11 from the beam irradiation unit 11a is welded to the welding object together with the beam from the beam irradiation unit 11a. It is designed to spray around. Note that reference numeral 14 in FIG. 1 denotes a lamp.

  The turntable 20 is provided with a clamping portion 21 so that the height of the area to be welded by the welding target is matched with the height of the beam irradiation position. In addition, the rotary table 20 has a shaft 31 of the driving unit 30 inserted in the bottom, is supported by a support 41 of the auxiliary unit 40 on the side opposite to the beam irradiator 11, and is horizontally supported by the driving unit 30. It is free to rotate. Here, in the drive unit 30, the motor 33 is connected to the shaft 31 via the speed reducer 34 by the connecting part 32, and the rotational speed of the motor 33 can be appropriately reduced by the speed reducer 34. Note that reference numeral 42 in the auxiliary unit 40 is a sensor that detects the position of the welding object, and reference numeral 43 is a sensor that detects the inclination of the clamping unit 21.

  With such a configuration, when the welding object is rotated in the horizontal direction and welded by the beam, oxygen around the area to be welded is removed by combustion of oxygen and nitrogen gas, so that the welding object is completed when welding is completed. The space between the inner container and the outer container is sealed to complete the vacuum structure. That is, since the welding process and the evacuation process are performed simultaneously, a vacuum space can be formed when the welding is completed.

  Further, in the example of FIG. 1, welding is performed while injecting nitrogen gas from the beam irradiation unit 11 a, but welding may be performed by installing the welding apparatus 1 in a chamber (chamber) filled with nitrogen gas. Good. In this case, the space between the inner container and the outer container is sealed in the room, and a vacuum space is formed when the space is taken out of the room.

  Further, instead of applying nitrogen gas, welding may be performed by setting the welding apparatus 1 in a room at a relatively high temperature, preferably in a room of 30 to 100 ° C., and diluting the air. Similar welding may be performed under vacuum conditions). Also in these cases, the space between the inner container and the outer container is sealed by the completion of the welding in the room, and a vacuum space is formed at the time when it is taken out of the room, that is, at room temperature or normal pressure. Moreover, you may evacuate combining these each conditions. In short, it is only necessary to perform welding in an environment where oxygen is easily removed or in the absence of oxygen, and a vacuum space can be formed after welding.

  Since welding in a room filled with nitrogen gas or under vacuum conditions can be sealed more precisely, it is suitable for relatively large welding objects and welding objects that require precision even if small. It is. Also, welding in a room under a relatively high temperature condition can speed up the removal of oxygen, so that it takes a long time to remove oxygen only by injecting nitrogen gas with a large surface area like a relatively large object to be welded. Suitable for easy-to-use items.

  As can be seen from the description so far, in the present invention, “the welding process and the evacuation process are simultaneously performed” does not need to be performed at completely the same timing, and one process is started earlier or later. For example, as described above, after adjusting the relative high temperature condition and the vacuum condition, welding may be performed under the condition. The welding process and the evacuation process may be performed by an apparatus or system other than the illustrated welding apparatus 1 as long as they can be performed simultaneously, but it is needless to say that the welding process and the vacuuming process are preferably performed by the same apparatus or system.

  Next, a specific welding method in the thermos 50 will be described. As shown in FIG. 3, the thermos 50 forms a structure including a cap 60, a container main body 70, and a bottom 80 in order from the top as constituent members before welding. In addition, about formation of the structure before this welding, it can carry out by a well-known method.

  In the thermos 50, screw portions 61 and 71 for fastening the cap 60 to the container body 70 are formed in the engagement area between the inner surface of the cap 60 and the cap 60 of the container body 70, respectively.

  The container body 70 includes an inner container 72 and an outer container 73, and a space 74 is formed between them. This space 74 becomes a vacuum space after the above-described welding.

  The inner container 72 and the outer container 73 are welded at the upper end. For this welding, the above-described welding apparatus 1 for the present invention may be used, or a known welding apparatus may be used. Below the screw part 71 of the outer container 73 is a side part 75 which is formed to have a diameter larger than at least the screw part 71 and extends linearly to the bottom part 80. Between the screw part 71 and the side part 75, the large diameter part 76 formed larger diameter than both is provided, and the cap 60 is prevented from slipping down by this.

  As shown particularly in FIG. 4, a groove 77 is formed along the circumferential direction at the lower end of the side portion 75, and the bottom portion 80 is fitted in the longitudinal direction so that the surface position is aligned with the side portion 75. The space 74 is closed. That is, since the bottom 80 seals the container main body 71 when welding is completed by the welding apparatus 1, the bottom 80 functions as a vacuum holding unit that holds the vacuum space of the space 74 after welding. And this bottom part 80 is welded to the outer container 73 of the container main body 70 by the welding apparatus 1, and the space 74 is evacuated.

  It is preferable that the container main body 70 and the bottom portion 80 are made of the same stainless material, and the cap 60 and at least the screw portion 71 are made of the same stainless material. Although there is no restriction | limiting in particular as a stainless steel material, For example, SUS304, SUS316, SUS430, SUS445 etc. are mentioned suitably.

  Thus, since the same material is welded and evacuated, the container main body 70 and the bottom 80 as members constituting the thermos bottle 50 can be thinned, and can be lightweight and excellent in strength. Moreover, since a different material from the member which comprises the thermos 50 is not used for vacuuming, there is no fear that an interface may arise between materials, and it can improve corrosion resistance. However, different materials such as brazing material may be welded in order to ensure complete evacuation or build up for design.

  In addition, it is preferable that each of the inner container 72, the outer container 73, and the bottom 80 of the container body 70 has a phase with a higher nitrogen (molecule) concentration than the inside on the space 74 side surface. Thereby, corrosion resistance can be improved. A similar phase may be formed on a surface that is not on the space 74 side.

  In forming this high nitrogen concentration phase, a method of injecting nitrogen gas into the space 74 at the time of welding, that is, the method of the present invention described above may be used, or an atmosphere filled with nitrogen gas in a plate-like or pre-weld state. The stainless steel material may be heated at a temperature at which nitrogen adsorption is possible at 1200 ° C. or less (usually the temperature at which nitrogen adsorption is performed), and nitrogen may be adsorbed on the surface. Further, in order to adsorb nitrogen on the surface, the surface may be in an austenite phase, an austenite-based material may be used, or the surface nitrogen concentration may be relatively high with respect to the inside. Good. When the austenite phase is used or when the nitrogen concentration is relatively high, the thickness of the portion is preferably 10 to 200 μm, for example.

  Next, a method for welding the bottom 80 to the outer container 73 will be described. As particularly shown in FIG. 5A, there is a slight gap 90 between the tip end where the bottom portion 80 is fitted in the groove 77 of the outer container 73 and the side surface of the groove 77. When the bottom 80 is welded by the welding device 1, the gap 90 has a relatively large amount of metal in the bottom 80 and a relatively small amount of metal in the outer container 73 (side surface of the groove 77). ) Melt the part enclosed in the oval shape inside. Thereby, as shown in FIG.5 (b), the weld metal part 100 which accumulates in a substantially perpendicular direction with the fitting direction (side surface direction of the groove | channel 77) of the bottom part 80 is formed. In this way, by forming the weld metal part 100 in a direction different from the fitting direction of the bottom part 80, the outer container 73 serving as the wall surface of the gap 90 and the metal of the bottom part 80 can be used, so only by melting a small amount of metal, High strength and reliable welding is possible. In other words, if the weld metal part 100 is formed in a direction different from the fitting direction of the bottom part 80, the welded metal part 100 can be reliably welded using the wall surface of the gap 90 while reducing the amount of metal to be melted. You don't have to.

  The weld metal part 100 is such that the deepest position is within the metal of the outer container 73 with respect to the surface of the outer container 73 (the surface on which the beam is irradiated by the welding apparatus 1), that is, the surface on the space 74 side. It is formed to a shallower position. If it is formed to a position deeper than the surface on the space 74 side, it may be difficult to sufficiently evacuate the space 74.

  Further, the bottom 80 has a position where it abuts the groove 77, and a small gap 91 is present in front of this position. The weld metal portion 100 is formed so that the width W at the shallowest position is maximized so that the molten metal does not spread into the gap 91 as much as possible, and preferably does not enter the gap 91. As a result, the amount of metal to be melted can be reduced, and welding between the outer container 73 and the bottom 80 can be made more reliable.

  As described above, in the method for manufacturing a vacuum structure according to the present invention, the welding process for welding the members constituting the vacuum structure and the vacuuming process for forming the vacuum space are simultaneously performed, so the structure is formed. It is not necessary to go through a vacuum process later, and the number of processes can be reduced.

  As mentioned above, although embodiment of this invention was described in detail, the vacuum structure of this invention is not limited to the said embodiment. For example, in the above-described embodiment, a thermos bottle has been described as an example of the vacuum structure. However, the present invention is not limited to this and can be applied to a vacuum cylinder, a vacuum tank, a float, a vacuum sphere, and the like.

  In the above embodiment, the bottom part is welded to the outer container as a vacuum holding part. However, in the same structure as this, for example, in a vacuum structure having a large capacity such as a vacuum tank, the inner wall is made to be a vacuum holding part. And may be welded with the inner container. Moreover, you may make it weld with a container main body by making several places into a vacuum holding part. In this case, the fitting direction may be the radial direction if the vacuum structure is a sphere, or the height direction (short side) if the diameter of the vacuum structure is larger than the height. Direction).

  Furthermore, in the said embodiment, although the metal of both the outer container 73 of the container main body 70 and the bottom part 80 used as a vacuum holding part is melt | dissolved, it is not limited to this. For example, as shown in FIG. 6, the bottom 80 is pressure-bonded to the groove 77 and irradiated with a beam (see the arrow in the figure) at one point of the bottom 80, thereby melting the surrounding metal and welding metal parts. It is good also as performing what is called spot welding which forms 100 and welds. Further, as shown in FIG. 7, a groove 78 is formed in the container body 70, a bottom portion 80 is fitted therein, and a beam is irradiated to a corner portion 81 formed by the container body 70 and the bottom portion 80. Thus, welding may be performed by melting the surrounding metal to form the weld metal portion 100.

DESCRIPTION OF SYMBOLS 1 Welding apparatus 10 Apparatus main body 11 Beam irradiation machine 11a Beam irradiation part 12 Installation stand 13 Nitrogen gas injection part 14 Lamp 20 Rotation stand 30 Drive part 31 Axis 32 Connection tool 33 Motor 34 Decelerator 40 Auxiliary part 41 Support tool 42 Sensor 43 Sensor 50 Thermos (vacuum structure)
60 Cap 61 Screw part 70 Container body 71 Screw part 72 Inner container 73 Outer container 74 Space (vacuum space)
75 Side part 76 Large diameter part 77 Groove 78 Alignment groove 80 Bottom (vacuum holding part)
81 Corner portion 90 Clearance 91 Clearance 100 Weld metal part W Width of weld metal part at the shallowest position

Claims (9)

  A manufacturing method of a vacuum structure including an inner container and an outer container, in which a vacuum space is formed, the welding step of welding members constituting the vacuum structure, and forming the vacuum space A vacuum structure manufacturing method comprising performing a vacuuming step simultaneously.   The method for manufacturing a vacuum structure according to claim 1, wherein in the welding step, welding is performed using a material of a member constituting the vacuum structure.   The manufacturing method of the vacuum structure of Claim 1 or 2 which provides nitrogen gas, irradiating a beam to the area | region to weld.   The method of manufacturing a vacuum structure according to any one of claims 1 to 3, wherein a beam is irradiated to a region to be welded under a relatively high temperature condition.   The manufacturing method of the vacuum structure in any one of Claim 1 to 4 which irradiates a beam to the area | region to weld on vacuum conditions. A container body including an inner container and an outer container, in which a vacuum space is formed;
A vacuum structure made of the same material as the container main body, and having a vacuum holding section that is welded to the container main body so as to seal the vacuum space and holds the vacuum state of the vacuum space. A container body including an inner container and an outer container, in which a vacuum space is formed;
Made of the same material as this container body, fitted into the container body, welded to the container body so as to seal the vacuum space, and holding a vacuum state of the vacuum space,
And a welding metal part stored in a direction different from the fitting direction of the vacuum holding part.   The weld metal portion is formed so that the deepest position is shallower than the surface of the container main body on the side of the vacuum space, with reference to the surface of the container main body opposite to the vacuum space side. The vacuum structure according to claim 6 or 7, wherein the vacuum structure is formed so that the width of the shallow position is maximized.   The vacuum structure according to any one of claims 6 to 8, wherein the container main body and the vacuum holding part are formed of a stainless material and have a phase having a higher nitrogen concentration than the inside on at least the surface on the vacuum space side.