JP3606640B2

JP3606640B2 - Method for manufacturing vacuum insulated container made of high strength stainless steel

Info

Publication number: JP3606640B2
Application number: JP16937595A
Authority: JP
Inventors: 一雄古市
Original assignee: 一雄古市
Priority date: 1995-06-13
Filing date: 1995-06-13
Publication date: 2005-01-05
Anticipated expiration: 2020-01-05
Also published as: JPH08337275A

Description

【０００１】
【産業上の利用分野】
本発明は、高強度ステンレス鋼製真空断熱容器の製造方法に、詳しくは、真空炉方式による高強度ステンレス鋼製真空断熱容器の製造方法に関する。
【０００２】
【従来の技術】
ステンレス魔法瓶を含むステンレス鋼製真空断熱容器は、図１Ａに示すとおり一般に、内筒１ｂと排気孔ポート４を有する外筒１ａとの間に真空室２を設けた本質的に二重壁構造（ただし、ビア樽として使用される高強度ステンレス鋼製真空断熱容器の場合は、頂面及び底面のいずれかは、再冷却のために一重壁とされている。）の樽本体１と口金３とからなっている。
ビール、とくに生ビールの保冷容器として使用するに適する高強度ステンレス鋼製真空断熱容器は、チップ管方式すなわち炉内で加熱しながら排気ポート４に溶接した排気孔に連通するチップ管と呼ばれる細管を通して排気し、所定の真空度に達した時または後、チップ管を押し潰し、真空ポンプとの連結管を取り外し、次いでチップ管の端部を溶封するという煩雑な方式で製造されてきた。この方式の場合、上記の手順を各樽ごとに繰り返すことになるので生産性が低く経費も嵩む。
【０００３】
他方、ステンレス魔法瓶と称される小型のステンレス鋼製真空断熱容器の場合は、容器を図１Ｂ及び図２Ａ、Ｂに示すように倒置し、多数の容器を連続式真空加熱炉中で加熱しながら排気し、所定の真空度に達したとき又は後、容器の温度を１０００℃前後に上げ排気孔６を有する皿状の窪み５からなる排気ポート４上にステンレス鋼片７ａと共に載置されてあるニッケルろう７を溶融して（図２Ｂの７’）排気孔６を封止する方式で製造されている。この方式は、作業手順が簡単であり生産性も高いが、ニッケルろうを溶融するために１０００度℃もの高温に加熱すると樽母材のテンレス鋼が変質し著しく剛性を失うので、小型の品物の製造には適するが、高い強度と剛性が要求されるビア樽のような大型製品の製造には適用することが困難である。
【０００４】
近時、高融点のニッケルろうに変えて５００℃前後の低温度で溶融するガラスろう７（図３、参照）の使用が提案され、ステンレス魔法瓶の製造に利用されている。しかし、ガラスろう封７’は、本質的に脆弱であり、取扱中に大きい機械的衝撃を受けまた高温高圧水による洗浄作業中に熱衝撃を受ける恐れのある、大型のステンレス鋼製真空断熱容器の製造にこれを利用した場合には、使用中に破損し樽自体を使用不可能にする危険が大である（封ろうが破損し、真空室に水や塵埃を含んだ空気の侵入した樽の再生は事実上不可能である。）。なお軟ろう（はんだ）は、ステンレス鋼との馴染み（接着）が悪く、真空を保持できない。
【０００５】
【発明が解決しようとする課題】
したがって本発明の目的は、生産性が高くしかも加工費が安い真空加熱炉方式によって、高耐久性で高強度のステンレス鋼製真空断熱容器製造する方法を提供するにある。
【０００６】
【課題を解決するための手段】
本発明においては、
内外筒間の空間（真空室２）を高真空度に排気するための排気孔６を設けた二重壁構造のステンレス鋼製容器を加熱しながら排気処理し、真空室２が所定の高真空度に達した時又は後、該排気孔６を封止することからなる高強度ステンレス鋼製真空断熱容器の製造方法において、
１）真空室内に該排気孔６（以下、第１の排気孔という）を覆うステンレス鋼製の隔壁８を設け、ここに該隔壁８は真空室に通じる排気孔９（以下、第２の排気孔という）を有し且つその全周縁８ａにおいて真空室壁に接着されており、
２）容器の加熱−排気処理を真空炉内で行い、
３）真空室が所定の高真空度に達した時又は後、熱溶融性封止材７、１０により第１の排気孔６及び第２の排気孔９を封止する。
【０００７】
【実施例】
本発明の好ましい実施例においては、図４Ａに示すとおり、排気孔６（第１の排気孔）を有する皿状の窪み５からなる排気ポート４を覆うように排気孔９（第２の排気孔）を有する隔壁８をその全周縁８ａにおいて外筒１ａに接着（好ましくは溶着）する。熱溶融性封止材１０は、たとえば隔壁８上に載置し、隔壁８の周縁８ａを上向きに外筒１ａに当接し、その状態で周縁８ａを外筒１ａに溶接することにより図示する位置に封入することができる。
【０００８】
排気孔９及び６の封止は、真空加熱炉内で連続して行う事が好ましいが、別法として、排気孔９の封止のみを真空加熱炉内で行い排気孔６の封止は炉外で行うこともできる。
【０００９】
前者の場合、熱溶融性封止材として融点約４５０℃〜約５００℃のガラスろうを共通に用いることができる。
しかし、第２の排気孔９の封止材として融点約４５０℃のガラスろうを第１の排気孔の封止材として融点約５００℃のガラスろうを用いるのが好ましい。図５は、この実施態様における真空加熱炉内の圧力（真空度）及び品温の変化を模式的に示すグラフであって、品温がＡ点に達するとゲッターが活性化されて点Ａ−Ｂ間で真空室内の残留ガスは完全にゲッターに吸収され、真空室内は超高真空（１０^−５）となり、他方、真空加熱炉内の圧力も真空室からのガス流出がなくなるためさらに低下すること，及び品温が点Ｃ度に達したとき第２の排気孔が封止され、点Ｄまで昇温されたとき第１の排気孔が封止されることを示す。
後者の場合にも、第２の排気孔の封止材としては融点約４５０℃〜約５００℃のガラスろうを用いることが必須であるが、第１の排気孔の封止材としては軟ろう（はんだ）など適宜のものを用いることができる。
【００１０】
【発明の効果】
従来のチップ管方式に比して遙に高い生産性かつ低費用で同等の品質の高強度ステンレス鋼製真空断熱容器を製造することができる。
【図面の簡単な説明】
【図１】高強度ステンレス鋼製真空断熱容器模式的断面図。
【図２】ステンレス魔法瓶の製造における排気孔の封止手段の一例の説明図。
【図３】ステンレス魔法瓶の製造における排気孔の封止手段の他の一例の説明図。
【図４】本発明の方法の説明図。
【図５】本発明の一実施態様における真空加熱炉内の圧力（真空度）及び品温の変化を模式的に示すグラフ。
【符号の説明】
１容器本体
１ａ外筒
１ｂ内筒
２真空室
３口金
４排気ポート
５皿状窪み
６排気孔
７ろう
７’ ろう封
７ａニッケル鋼片
８隔壁
８ａ隔壁周縁
９第２排気孔
１０ガラスろう
１０’ ガラスろう封[0001]
[Industrial application fields]
The present invention relates to a method for producing a high-strength stainless steel vacuum insulated container, and more particularly to a method for producing a high-strength stainless steel vacuum insulated container by a vacuum furnace method.
[0002]
[Prior art]
As shown in FIG. 1A, a stainless steel vacuum insulated container including a stainless steel thermos bottle generally has an essentially double wall structure in which a vacuum chamber 2 is provided between an inner cylinder 1b and an outer cylinder 1a having an exhaust hole port 4 ( However, for high-strength stainless steel vacuum insulation vessel used as a via barrel, the one of the top and bottom surfaces, the barrel main body 1 and the base 3 of which is a single-wall for re-cooling.) It is made up of.
A vacuum insulated container made of high-strength stainless steel suitable for use as a cold storage container for beer, particularly draft beer, is exhausted through a tip tube system, that is, a narrow tube called a tip tube communicating with an exhaust hole welded to an exhaust port 4 while being heated in a furnace. However, when a predetermined degree of vacuum is reached or after, the tip tube is crushed, the connecting tube with the vacuum pump is removed, and then the end of the tip tube is sealed. In the case of this method, the above procedure is repeated for each barrel, so the productivity is low and the cost is increased.
[0003]
On the other hand, in the case of a small stainless steel vacuum insulated container called a stainless steel thermos, the container is turned upside down as shown in FIGS. 1B and 2A, B, and a number of containers are heated in a continuous vacuum heating furnace. After evacuating and reaching a predetermined degree of vacuum, the temperature of the container is raised to around 1000 ° C. and placed on the exhaust port 4 consisting of the dish-like recess 5 having the exhaust hole 6 together with the stainless steel piece 7a. The nickel braze 7 is melted (7 'in FIG. 2B) and the exhaust hole 6 is sealed. This method has a simple work procedure and high productivity, but when heated to a temperature as high as 1000 ° C to melt nickel brazing, the barrel base material's tentress steel changes in quality and loses its rigidity significantly. Although suitable for manufacturing, it is difficult to apply to manufacturing large products such as beer barrels that require high strength and rigidity.
[0004]
Recently, it has been proposed to use a glass solder 7 (see FIG. 3) that melts at a low temperature of about 500 ° C. instead of a high melting point nickel solder, and is used in the manufacture of stainless steel thermos bottles. However, the glass braze 7 'is inherently fragile, and is a large stainless steel vacuum insulated container that is subject to significant mechanical shock during handling and thermal shock during cleaning with high temperature and high pressure water. If this is used in the manufacture of a glass, there is a great risk that it will be damaged during use and the barrel itself will become unusable (the sealing wax will be damaged, and the vacuum chamber will be infiltrated with air containing water and dust). Is virtually impossible to reproduce.) Soft solder (solder) is not well-adapted (adhered) to stainless steel and cannot hold a vacuum.
[0005]
[Problems to be solved by the invention]
Accordingly, an object of the present invention is to provide a method for producing a highly durable and high-strength stainless steel vacuum insulated container by a vacuum heating furnace system with high productivity and low processing costs.
[0006]
[Means for Solving the Problems]
In the present invention,
A double-walled stainless steel container provided with an exhaust hole 6 for exhausting the space between the inner and outer cylinders (vacuum chamber 2 ) to a high degree of vacuum is exhausted while heating, and the vacuum chamber 2 has a predetermined high vacuum. In the method of manufacturing a high-strength stainless steel vacuum insulated container consisting of sealing the exhaust hole 6 when or after reaching the degree,
1) A stainless steel partition wall 8 that covers the exhaust hole 6 (hereinafter referred to as a first exhaust hole) is provided in the vacuum chamber, and the partition wall 8 is provided with an exhaust hole 9 (hereinafter referred to as a second exhaust gas) that leads to the vacuum chamber. And is bonded to the vacuum chamber wall at the entire periphery 8a thereof,
2) The container is heated and evacuated in a vacuum furnace.
3) When the vacuum chamber reaches a predetermined high degree of vacuum, the first exhaust hole 6 and the second exhaust hole 9 are sealed with the hot-melt sealing materials 7 and 10.
[0007]
【Example】
In a preferred embodiment of the present invention, as shown in FIG. 4A, an exhaust hole 9 (second exhaust hole) is provided so as to cover the exhaust port 4 composed of a dish-like recess 5 having an exhaust hole 6 (first exhaust hole). ) Is bonded (preferably welded) to the outer cylinder 1a at the entire peripheral edge 8a. The hot-melt sealing material 10 is placed on, for example, the partition wall 8, the peripheral edge 8a of the partition wall 8 is brought into contact with the outer cylinder 1a upward, and the peripheral edge 8a is welded to the outer cylinder 1a in this state. Can be encapsulated.
[0008]
The exhaust holes 9 and 6 are preferably sealed continuously in a vacuum heating furnace. Alternatively, only the exhaust holes 9 are sealed in the vacuum heating furnace, and the exhaust holes 6 are sealed in the furnace. It can also be done outside.
[0009]
In the former case, a glass wax having a melting point of about 450 ° C. to about 500 ° C. can be commonly used as the hot-melt sealing material.
However, it is preferable to use a glass wax having a melting point of about 450 ° C. as the sealing material for the second exhaust hole 9 and a glass wax having a melting point of about 500 ° C. as the sealing material for the first exhaust hole. FIG. 5 is a graph schematically showing changes in the pressure (degree of vacuum) and the product temperature in the vacuum heating furnace in this embodiment. When the product temperature reaches point A, the getter is activated and the point A- The residual gas in the vacuum chamber is completely absorbed by the getter between B and the vacuum chamber becomes ultra-high vacuum (10 ⁻⁵ ). On the other hand, the pressure in the vacuum heating furnace is further reduced because there is no gas outflow from the vacuum chamber. This indicates that the second exhaust hole is sealed when the product temperature reaches the point C degrees and that the first exhaust hole is sealed when the temperature is increased to the point D.
Even in the latter case, it is essential to use a glass wax having a melting point of about 450 ° C. to about 500 ° C. as the second exhaust hole sealing material, but the first exhaust hole sealing material is soft wax. An appropriate material such as (solder) can be used.
[0010]
【The invention's effect】
High-strength stainless steel vacuum insulated containers of the same quality can be manufactured with much higher productivity and lower cost than conventional tip tube systems.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view of a vacuum insulated container made of high-strength stainless steel.
FIG. 2 is an explanatory view of an example of a sealing means for exhaust holes in the manufacture of a stainless steel thermos bottle.
FIG. 3 is an explanatory diagram of another example of a sealing means for exhaust holes in the manufacture of a stainless steel thermos bottle.
FIG. 4 is an explanatory diagram of the method of the present invention.
FIG. 5 is a graph schematically showing changes in pressure (degree of vacuum) and product temperature in a vacuum heating furnace in one embodiment of the present invention.
[Explanation of symbols]
1 container body 1a outer cylinder 1b inner cylinder
2 vacuum chamber
3 caps
4 exhaust port 5 dish-shaped recess 6 exhaust hole 7 brazing 7 'brazing seal 7a nickel steel piece 8 partition 8a partitioning edge 9 second exhaust hole 10 glass brazing 10' glass brazing

Claims

内外筒間の空間（以下、真空室という）を高真空度に排気するための排気孔を設けた二重壁構造のステンレス鋼製容器を加熱しながら排気処理し、真空室が所定の高真空度に達した時又は後、該排気孔を封止することからなる高強度ステンレス鋼製真空断熱容器の製造方法において、
１）真空室内に該排気孔（以下、第１の排気孔という）を覆うステンレス鋼製の隔壁を設け、ここに該隔壁は真空室に通じる排気孔（以下、第２の排気孔という）を有し且つその全周縁において真空室壁に接着されており、
２）容器の加熱−排気処理を真空炉内で行い、
３）真空室が所定の高真空度に達した時又は後、熱溶融性封止材により第１の排気孔及び第２の排気孔をそれぞれ封止する、
ことを特徴とする方法。A stainless steel container with a double wall structure provided with an exhaust hole for exhausting the space between the inner and outer cylinders (hereinafter referred to as the vacuum chamber) to a high degree of vacuum is exhausted while heating, and the vacuum chamber has a predetermined high vacuum. In the method of manufacturing a high-strength stainless steel vacuum insulated container consisting of sealing the exhaust hole when or after reaching the degree,
1) A stainless steel partition wall covering the exhaust hole (hereinafter referred to as the first exhaust hole) is provided in the vacuum chamber, and the partition wall has an exhaust hole (hereinafter referred to as the second exhaust hole) communicating with the vacuum chamber. And bonded to the vacuum chamber wall at the entire periphery thereof,
2) The container is heated and evacuated in a vacuum furnace.
3) When the vacuum chamber reaches a predetermined high vacuum degree or after, the first exhaust hole and the second exhaust hole are respectively sealed with a hot-melt sealing material.
A method characterized by that.

第１の排気孔が外筒壁に設けられる請求項１の方法。The method of claim 1, wherein the first exhaust hole is provided in the outer cylinder wall.

熱溶融性封止材は低融点（又は軟化点）の硬ろう又はガラス系ろうである請求項１又は２の方法。The method according to claim 1 or 2, wherein the hot-melt sealing material is a low melting point (or softening point) hard or glass-based braze.

第１の排気孔の封止材として第２の排気孔の封止材より高融点（又は軟化点）のものを使用し、第２の排気孔の封止後、昇温して第１の排気孔を封止する請求項１、２又は３の方法。As the first exhaust hole sealing material, a material having a higher melting point (or softening point) than the second exhaust hole sealing material is used. The method according to claim 1, 2 or 3, wherein the exhaust hole is sealed.

第２の排気孔の封止は真空炉内で行い、第１の排気孔の封止は真空炉外で行う請求項１、２又は３の方法。The method according to claim 1, 2 or 3, wherein the second exhaust hole is sealed in a vacuum furnace, and the first exhaust hole is sealed outside the vacuum furnace.

第１の排気孔の封止に軟ろうを使用する請求項５の方法。6. The method of claim 5, wherein a soft solder is used to seal the first exhaust hole.