JP4173350B2

JP4173350B2 - Gas pipe sealing structure

Info

Publication number: JP4173350B2
Application number: JP2002312479A
Authority: JP
Inventors: 三兄保坂
Original assignee: Koyo Sangyo Co Ltd
Current assignee: Koyo Sangyo Co Ltd
Priority date: 2002-10-28
Filing date: 2002-10-28
Publication date: 2008-10-29
Anticipated expiration: 2022-10-28
Also published as: JP2004144265A

Description

【０００１】
【発明の属する技術分野】
この発明は、互いに回動可能に嵌合された二つのガス管の嵌合部を耐火材からなるシール部材によって封止するようにしたガス管の封止構造に関する。この発明において、ガス管とは、鉄管等の通常のガス管のみならず、例えばガス栓の流入側若しくは流出側端部、又は継手のようなガスを流通させる全ての管状のものをも含む。
【０００２】
【従来の技術】
従来、鉄製の二つのガス管を接続する場合には、まず一方のガス管に継手（ガス管）の一端部を回動可能に、かつ軸線方向へ移動不能に嵌合する。その後、継手の他端部に形成された雌ねじ部に他方のガス管を螺合させる。そして、継手を回転させることにより、他方のガス管を継手に螺合固定する。これによって、二つのガス管を接続している。
【０００３】
ところで、一方のガス管の内周面とこれに回動可能に嵌合される継手の外周面との間には、継手の回動を許容するための不可避の隙間が存在する。この隙間からガスが漏れるのを防止するために、内周面と外周面との間には、Ｏリング等のシール部材が装着されている。ところが、Ｏリング等のシール部材は、高温で溶融ないしは焼失してしまう。このため、火災時等にはガス管と継手との間の隙間からガスが漏れるおそれがある。
【０００４】
そこで、ガス管と継手との嵌合部には、それらの軸線方向に対向する第１、第２の対向面を形成し、この対向面間にリング状をなす金属製のシール部材を配置する。そして、シール部材の一端面と他端面とを第１、第２の対向面にそれぞれ押圧接触させることにより、ガス管と継手との間を封止するようにしている。この場合、継手の回動を許容するとともに、所定の密封性を得るために、シール部材を皿ばね状に形成し、その弾性を利用してシール部材を第１、第２の対向面に押圧接触させるようにしていた（例えば、特許文献１参照。）。
【０００５】
【特許文献１】
特開平１１−１４２２０６号公報（第４頁、第１図）
【０００６】
【発明が解決しようとする課題】
皿ばね状のシール部材を用いた場合には、シール部材の幅（シール部材の軸線方向における一端面と他端面との間の最大間隔）精度を高精度なものにする必要がある。仮に、シール部材の幅精度が低いと、第１、第２の対向面間に装着されるシール部材の弾性変形量が各シール部材毎に異なる大きさになる。その結果、シール部材と第１、第２対向面との接触圧に大きなバラツキが生じ、所定の密封性が得られない事態を招来するおそれがあるからである。ところが、皿ばね状をなすシール部材の幅を高精度にすることは比較的困難であり、幅精度を向上させようとするとシール部材の製造費が高騰してしまう。この結果、ガス管と継手との接続費用が嵩むという問題があった。
【０００７】
【課題を解決するための手段】
この発明は、上記の問題を解決するためになされたもので、一対のガス管の回動可能に嵌合された各嵌合部に、当該嵌合部の軸線方向に対向する対向面がそれぞれ上記軸線を中心として環状に形成され、この二つの対向面間に耐火材からなる弾性変形可能な環状のシール部材が設けられ、上記シール部材によって上記二つの対向面間が封止されたガス管の封止構造において、上記シール部材の両端面を上記軸線と直交する平面とし、上記二つの対向面の一方に他方の対向面側に突出する第１当接部を環状に形成し、上記他方の対向面に上記一方の対向面側に突出する第２当接部を環状に形成し、上記シール部材を上記軸線方向へ弾性変形させた状態で、上記第１当接部を上記シール部材の一端面の内周側に押圧接触させるとともに、上記第２当接部を上記シール部材の他端面の外周側に押圧接触させ、それによって上記二つの対向面間を上記シール部材によって封止したことを特徴としている。
この場合、上記第１、第２当接部を、上記第１当接部が上記第２当接部に対して上記軸線方向において上記他方の対向面側に位置するように配置し、それによって上記シール部材を上記軸線方向へ弾性変形させた状態で上記第１、第２当接部を上記シール部材の一端面と他端面とにそれぞれ押圧接触させることが望ましい。あるいは、上記第１、第２当接部を、それらの間に上記軸線方向における間隔が上記シール部材の厚さより小さい隙間が形成されるように配置し、それによって上記シール部材を上記軸線方向へ弾性変形させた状態で上記第１、第２当接部を上記シール部材の一端面と他端面とにそれぞれ押圧接触させるようにしてもよい。
【０００８】
【発明の実施の形態】
以下、この発明に係るガス管の封止構造を、鉄製のガス管とこのガス管に他の鉄製のガス管を接続するための継手（ガス管）との間に適用した実施の形態について図１〜図５を参照して説明する。勿論、この発明は、ガス管と継手以外の互いに回動可能に接続されるガス管どうしの封止構造にも適用可能である。
【０００９】
図１〜図４は、この発明の一実施の形態を示す。これら図において、符号１は鉄製のガス管であり、符号２はガス管１に軸線Ｌを中心として回動可能に連結された鉄製の継手（ガス管）である。
【００１０】
ガス管１は、断面円形に形成されており、その外周面１１の左端部（図における左端部。以下、左右は図における左右を意味するものとする。）には、小径部１２と嵌合部１３とが左端縁から右側へ向かって順次形成されている。小径部１２及び嵌合部１３は、それぞれの軸線を軸線Ｌと一致させて形成されており、いずれも外周面１１より小径に形成されている。しかも、小径部１２は嵌合部１３より小径に形成されている。小径部１２には、取付凹部１４が環状に形成されている。この取付凹部１４には、弾性的に拡縮径可能なストップリング３が軸線Ｌ方向へ移動不能に装着されている。ストップリング３は、それに外力が作用しない自然状態においてその外周部が取付凹部１４から突出させており、縮径可能な状態で取付凹部１４に装着されている。嵌合部１３の右端縁と外周面１１の左端縁との間には、第１の対向面（対向面）１５が形成されている。この第１の対向面１５は、軸線Ｌと直交する平面として形成されている。
【００１１】
上記継手２は、ガス管１に他のガス管（図示せず）を接続するためのものであり、その内周面２１の右端部には、嵌合孔部２２と小径孔部２３とが継手２の右端縁から左方へ向かって順次形成されている。嵌合孔部２２の右端部には、嵌合部１３が回動可能に嵌合されている。これにより、継手２がガス管１に軸線Ｌを中心として回動可能に連結されている。なお、嵌合孔部２２の内周面と嵌合部１３の外周面及び小径部１２の外周面との各間は、Ｏリング等のシール部材４，５によってそれぞれ気密に封止されている。
【００１２】
小径孔部２３の内径は、外力が作用しない自然状態時におけるストップリング３の外径とほぼ同一か若干小径になっており、その内周面の右端部には、係合突出部２４が環状に形成されている。この係合突出部２４の内径は、自然状態のストップリング３の外径より小径になっており、係合突出部２４の左方を向く面がストップリング３に突き当たることにより、継手２がガス管１から左方へ抜け出ることが阻止されている。係合突出部２４がストップリング３に突き当たった状態のとき、継手２の右端面が第１の対向面１５と所定の間隔をもって対向しており、継手２の右端面が第２の対向面（対向面）２５になっている。継手２の内周面２１の左端部には、テーパ雌ねじ孔部２６が形成されている。このテーパ雌ねじ孔部２６には、他のガス管が螺合固定される。これにより、他のガス管がガス管１に継手２を介して接続されるようになっている。なお、他のガス管は、継手２を回転させることによって容易に螺合固定することができる。
【００１３】
図２に示すように、第１の対向面１５の内周部には、軸線Ｌに沿って第２の対向面２５側へ突出する小径突出部１６が環状に形成されている。小径突出部１６の左端面は軸線Ｌと直交する平面として形成されており、小径突出部１６の左端面と外周面との交差部が第１当接部１７になっている。したがって、この実施の形態では、第１当接部１７が、直角に屈曲した角部として形成されているが、小径突出部１６の左端面と外周面との交差部に円弧面を形成し、この円弧面を第１当接部とするのが望ましい。
【００１４】
一方、第２の対向面２５の外周部には、軸線Ｌに沿って第１の対向面１５側へ突出する大径突出部２７が環状に形成されている。大径突出部２７は、小径突出部１６より大径に形成されている。大径突出部２７の右端面は軸線Ｌと直交する平面として形成されており、大径突出部２７の右端面と外周面との交差部が第２当接部２８になっている。したがって、この実施の形態においては、第２当接部２８も直角に屈曲した角部として形成されているが、大径突出部２７の右端面と外周面との交差部に円弧面を形成し、この円弧面を第２当接部とするのが望ましい。第２当接部２８は、大径突出部２７が小径突出部１６より大径であることから、第１当接部１７より大径になっている。しかも、第２当接部２８は、係合突出部２４がストップリング３に突き当たった状態（図１に示す状態）になっているとき、第１当接部１７より第１の対向面１５側に位置するように配置されている。
【００１５】
第１の対向面１５と第２の対向面２５との間には、シール部材６が配置されている。シール部材６は、鋼等の金属、その他の弾性と耐火性とを有する材質からなるものであり、厚さの薄いリング体として形成されている。シール部材６の内径は嵌合部１３の外径とほぼ同一であり、嵌合部１３に外挿されている。シール部材６の外径は第２当接部２８より大径になっている。シール部材６の両端面は、その軸線と直交する平面になっている。したがって、シール部材６の両端面は、シール部材６に外力が作用しない自然状態では軸線Ｌと直交している。
【００１６】
上記のように、第２当接部２８が第１当接部１７に対して第１の対向面１５側に位置しているので、シール部材６の右端面と左端面とは、第１、第２当接部１７，２８にそれぞれ突き当たる。しかも、シール部材６の右端面がその内周側において第１当接部１７に突き当たり、シール部材６の左端面が、右端面と第１当接部１７との当接部より外周側において第２当接部２８に突き当たるので、シール部材６は軸線Ｌ方向へ弾性変形させられる。この場合、シール部材６は、第２当接部２８と第１当接部１７との間の距離をＤとし、シール部材６の厚さをＴとすると、径方向における第１当接部１７と第２当接部との間において（Ｄ＋Ｔ）の分だけ軸線Ｌ方向へ弾性変形させられる。この弾性変形に伴う弾性復元力により、シール部材６の両端面が第１、第２当接部１７，２８にそれぞれ環状に押圧接触させられる。これにより、第１、第２の対向面１５，２５間がシール部材６によって気密に封止されている。
【００１７】
上記ガス管１と継手２とを連結する場合には、図３に示すように、ストップリング３、シール部材４，５，６をガス管１の所定の箇所に予めそれぞれ取り付けておく。そして、ガス管１をその小径部１２側から継手２の内部に嵌合孔部２２側から挿入する。ガス管１を所定の位置まで挿入すると、嵌合部１３が嵌合孔部２２に嵌合する。その後、ガス管１をさらに挿入すると、係合突出部２４の傾斜面２４ａがストップリング３に突き当たる。その状態でガス管１を継手２にさらに挿入すると、ストップリング３が傾斜面２４ａによって縮径される。そして、ついには図４に示すように、係合突出部２４の内周面がストップリング３の外周面に嵌合する。ガス管１を継手２にさらに挿入すると、大径突出部２７の先端面がシール部材６に突き当たる。このときには、係合突出部２４の内周面の左側の端部がストップリング３の外周面の右端部に距離（Ｄ＋Ｔ）の分だけ嵌合している。したがって、その状態からガス管１を継手２に対して距離（Ｄ＋Ｔ）だけさらに挿入すると、係合突出部２４がストップリング３から右方へ通過する。その結果、ストップリング３が拡径し、係合突出部２４がストップリング３の右端面に突き当たる。これによって、継手２のガス管１に対する左方への抜け止めがなされる。しかも、係合突出部２４がストップリング３に突き当たった状態においては、シール部材６が軸線Ｌ方向へ距離（Ｄ＋Ｔ）の分だけ弾性変形させられるので、シール部材６は、それ自体の弾性によって継手２を左方へ付勢し、係合突出部２４をストップリング３に突き当たった状態に維持する。これにより、ガス管１と継手２とが軸線Ｌ方向へほとんど移動不能に連結される。
【００１８】
上記のように構成されたガス管の封止構造においては、シール部材６の両端面が平面であるから、その幅寸法を容易に高精度にすることができる。したがって、シール部材６と第１、第２当接部１７，２８との接触圧のバラツキを小さく抑えることができる。しかも、シール部材６は、幅精度の向上を容易に行うことができるので、同程度の幅精度を有する皿ばね状のシール部材を製造する場合に比して、大幅に安価に製造することができる。したがって、ガス管と継手との連結費用を低減することができる。
【００１９】
図５は、この発明の他の実施の形態を示す。この実施の形態においては、大径突出部２７の先端面の外周部に、第１の対向面１５に向かって突出する遮蔽突出部２９が環状に形成されている。遮蔽突出部２９の内径は、シール部材６の外径より大径になっている。遮蔽突出部２９の突出量は（軸線Ｌ方向の長さ）は、シール部材６を覆い隠すのに十分な長さに設定されている。したがって、シール部材６を外部から見えないようにすることができ、これによって美観の向上が図られている。その他の構成は、上記実施の形態と同様である。
【００２０】
なお、この発明は、上記の実施の形態に限定されるものでなく、適宜変更可能である。
例えば、上記の実施の形態においては、ガス管１の第１の対向面１５に小径突出部１６及び第１当接部１７を形成する一方、継手２の第２の対向面２５に大径突出部２７及び第２当接部２８を形成しているが、第１の対向面１５の外周部に第２の対向面２５側へ突出する大径突出部を形成するとともに、この大径突出部の内周側の角部に第２当接部を形成し、第２の対向面２５の内周部に第１の対向面１５側へ突出する小径突出部を形成するとともに、この小径突出部の外周側の角部に第１当接部を形成してもよい。
また、上記の実施の形態においては、大径突出部２７の先端部と小径突出部１６の先端部とを軸線Ｌ方向において重ならせることにより、第２当接部２８を軸線Ｌ方向において第１当接部１７より第１の対向面１５側に位置させているが、第２当接部を第１の対向面１５に対し第１当接部より離間するように配置し、軸線Ｌ方向において第１当接部１７と第２当接部２８との間に隙間を形成してもよい。ただし、その隙間の軸線Ｌ方向における間隔は、シール部材６の厚さＴより小さくする。このようにした場合には、隙間の軸線Ｌ方向における間隔をＩとし、シール部材６の厚さをＴとすると、シール部材６は第１、第２当接面１７，２８に突き当たることにより、長さ（Ｔ−Ｉ）の分だけ軸線Ｌ方向へ弾性変形させられる。
【００２１】
【発明の効果】
以上説明したように、この発明によれば、シール部材と第１、第２当接部との接触圧のバラツキを小さくすることができ、それによって第１、第２対向面間のシール性を一定の範囲内に抑えることができ、しかもガス管どうしを安価に連結することができるという効果が得られる。
【図面の簡単な説明】
【図１】この発明の一実施の形態を示す一部省略断面図である。
【図２】図１のＸ円部の拡大図である。
【図３】ガス管と継手とを連結する前の状態で示す一部省略断面図である。
【図４】ガス管と継手とを連結するト中の状態で示す一部省略断面図である。
【図５】この発明の他の実施の形態を示す一部省略断面図である。
【符号の説明】
１ガス管
２継手（ガス管）
６シール部材
１５第１の対向面（対向面）
１７第１当接部
２５第２の対向面（対向面）
２８第２当接部[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a gas pipe sealing structure in which a fitting portion of two gas pipes that are rotatably fitted to each other is sealed with a seal member made of a refractory material. In the present invention, the gas pipe includes not only a normal gas pipe such as an iron pipe but also all tubular pipes through which a gas flows, such as an inflow or outflow end of a gas stopper, or a joint.
[0002]
[Prior art]
Conventionally, when two steel gas pipes are connected, first, one end of a joint (gas pipe) is fitted to one gas pipe so as to be rotatable and immovable in the axial direction. Thereafter, the other gas pipe is screwed into the female thread formed at the other end of the joint. Then, the other gas pipe is screwed and fixed to the joint by rotating the joint. Thereby, two gas pipes are connected.
[0003]
By the way, there is an inevitable gap for allowing the joint to rotate, between the inner peripheral surface of one of the gas pipes and the outer peripheral surface of the joint that is rotatably fitted to the gas pipe. In order to prevent gas from leaking from the gap, a seal member such as an O-ring is mounted between the inner peripheral surface and the outer peripheral surface. However, sealing members such as O-rings melt or burn out at high temperatures. For this reason, in the event of a fire or the like, gas may leak from the gap between the gas pipe and the joint.
[0004]
Therefore, first and second opposing surfaces facing each other in the axial direction are formed at the fitting portion between the gas pipe and the joint, and a ring-shaped metal seal member is disposed between the opposing surfaces. . Then, the gap between the gas pipe and the joint is sealed by bringing the one end surface and the other end surface of the seal member into press contact with the first and second opposing surfaces, respectively. In this case, in order to allow rotation of the joint and to obtain a predetermined sealing property, the sealing member is formed in a disc spring shape, and the sealing member is pressed against the first and second opposing surfaces by utilizing its elasticity. It was made to contact (for example, refer patent document 1).
[0005]
[Patent Document 1]
Japanese Patent Laid-Open No. 11-142206 (page 4, FIG. 1)
[0006]
[Problems to be solved by the invention]
When a disc spring-like seal member is used, the accuracy of the width of the seal member (maximum distance between one end surface and the other end surface in the axial direction of the seal member) needs to be high. If the width accuracy of the seal member is low, the amount of elastic deformation of the seal member mounted between the first and second opposing surfaces becomes different for each seal member. As a result, the contact pressure between the sealing member and the first and second opposing surfaces may vary greatly, which may lead to a situation where a predetermined sealing property cannot be obtained. However, it is relatively difficult to make the width of the sealing member in the shape of a disc spring highly accurate, and if it is attempted to improve the width accuracy, the manufacturing cost of the sealing member increases. As a result, there is a problem that the connection cost between the gas pipe and the joint increases.
[0007]
[Means for Solving the Problems]
The present invention has been made to solve the above-described problems, and each of the fitting portions that are rotatably fitted to the pair of gas pipes has an opposing surface that faces the axial direction of the fitting portion, respectively. A gas pipe formed in an annular shape centering on the axis, and provided with an elastically deformable annular seal member made of a refractory material between the two opposing surfaces, and between the two opposing surfaces sealed by the seal member In this sealing structure, both end surfaces of the sealing member are flat surfaces perpendicular to the axis, and a first contact portion protruding toward the other opposing surface is formed in one of the two opposing surfaces, and the other A second abutting portion projecting toward the one facing surface is formed in an annular shape on the opposing surface of the sealing member, and the first abutting portion of the sealing member is elastically deformed in the axial direction. While making it press-contact with the inner peripheral side of one end surface, the said 2nd The contact portion is pressed against contact with the outer peripheral side of the other end face of the seal member, thereby being between said two opposing surfaces is characterized in that sealed by the sealing member.
In this case, the first and second contact portions are arranged so that the first contact portion is located on the other opposing surface side in the axial direction with respect to the second contact portion, thereby It is desirable that the first and second contact portions are pressed and brought into contact with one end surface and the other end surface of the seal member in a state where the seal member is elastically deformed in the axial direction. Alternatively, the first and second abutting portions are arranged such that a gap is formed between them in which the gap in the axial direction is smaller than the thickness of the sealing member, whereby the sealing member is moved in the axial direction. You may make it make the said 1st, 2nd contact part press-contact to the one end surface and the other end surface of the said seal member, respectively, in the state elastically deformed.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a gas pipe sealing structure according to the present invention will be described with respect to an embodiment in which the structure is applied between an iron gas pipe and a joint (gas pipe) for connecting another iron gas pipe to the gas pipe. 1 to 5 will be described. Of course, this invention is applicable also to the sealing structure of the gas pipes connected so that rotation is mutually possible other than a gas pipe and a coupling.
[0009]
1 to 4 show an embodiment of the present invention. In these drawings, reference numeral 1 denotes an iron gas pipe, and reference numeral 2 denotes an iron joint (gas pipe) connected to the gas pipe 1 so as to be rotatable about an axis L.
[0010]
The gas pipe 1 is formed in a circular cross section, and is fitted to the small diameter portion 12 at the left end portion of the outer peripheral surface 11 (left end portion in the figure. Hereinafter, left and right mean left and right in the figure). The part 13 is sequentially formed from the left end edge toward the right side. The small-diameter portion 12 and the fitting portion 13 are formed with their respective axes aligned with the axis L, and both are formed with a smaller diameter than the outer peripheral surface 11. Moreover, the small diameter portion 12 is formed to have a smaller diameter than the fitting portion 13. An attachment recess 14 is formed in the small diameter portion 12 in an annular shape. A stop ring 3 capable of elastic expansion and contraction is mounted on the mounting recess 14 so as not to move in the direction of the axis L. The stop ring 3 has an outer peripheral portion protruding from the mounting recess 14 in a natural state where no external force acts on the stop ring 3, and is mounted on the mounting recess 14 in a state where the diameter can be reduced. A first facing surface (facing surface) 15 is formed between the right end edge of the fitting portion 13 and the left end edge of the outer peripheral surface 11. The first facing surface 15 is formed as a plane orthogonal to the axis L.
[0011]
The joint 2 is for connecting another gas pipe (not shown) to the gas pipe 1, and a fitting hole portion 22 and a small-diameter hole portion 23 are formed at the right end portion of the inner peripheral surface 21. The joint 2 is formed sequentially from the right end edge to the left. The fitting portion 13 is rotatably fitted to the right end portion of the fitting hole portion 22. Thereby, the joint 2 is connected to the gas pipe 1 so as to be rotatable about the axis L. The space between the inner peripheral surface of the fitting hole 22 and the outer peripheral surface of the fitting portion 13 and the outer peripheral surface of the small diameter portion 12 is hermetically sealed by seal members 4 and 5 such as O-rings. .
[0012]
The inner diameter of the small-diameter hole 23 is substantially the same as or slightly smaller than the outer diameter of the stop ring 3 in a natural state where no external force is applied, and an engagement protrusion 24 is annular at the right end of the inner peripheral surface. Is formed. The inner diameter of the engagement protrusion 24 is smaller than the outer diameter of the stop ring 3 in the natural state, and the surface facing the left side of the engagement protrusion 24 abuts against the stop ring 3, thereby causing the joint 2 to gas. Exit from the tube 1 to the left is prevented. When the engagement protrusion 24 is in contact with the stop ring 3, the right end surface of the joint 2 faces the first facing surface 15 with a predetermined interval, and the right end surface of the joint 2 is the second facing surface ( (Opposite surface) 25. A tapered female screw hole 26 is formed at the left end of the inner peripheral surface 21 of the joint 2. Another gas pipe is screwed and fixed to the tapered female screw hole portion 26. As a result, another gas pipe is connected to the gas pipe 1 via the joint 2. The other gas pipes can be easily screwed and fixed by rotating the joint 2.
[0013]
As shown in FIG. 2, a small-diameter protruding portion 16 that protrudes toward the second facing surface 25 along the axis L is formed in an annular shape on the inner peripheral portion of the first facing surface 15. The left end surface of the small diameter protrusion 16 is formed as a plane orthogonal to the axis L, and the intersection of the left end surface of the small diameter protrusion 16 and the outer peripheral surface is the first contact portion 17. Therefore, in this embodiment, the first contact portion 17 is formed as a corner portion bent at a right angle, but an arc surface is formed at the intersection of the left end surface of the small-diameter protruding portion 16 and the outer peripheral surface, It is desirable that this circular arc surface be the first contact portion.
[0014]
On the other hand, a large-diameter protruding portion 27 that protrudes along the axis L toward the first opposing surface 15 is formed in an annular shape on the outer peripheral portion of the second opposing surface 25. The large diameter protrusion 27 is formed to have a larger diameter than the small diameter protrusion 16. The right end surface of the large-diameter protruding portion 27 is formed as a plane orthogonal to the axis L, and the intersection between the right end surface of the large-diameter protruding portion 27 and the outer peripheral surface is the second contact portion 28. Therefore, in this embodiment, the second abutting portion 28 is also formed as a corner portion bent at a right angle, but an arc surface is formed at the intersection of the right end surface of the large-diameter protruding portion 27 and the outer peripheral surface. It is desirable that this arc surface be the second contact portion. The second abutting portion 28 has a larger diameter than the first abutting portion 17 because the large-diameter protruding portion 27 has a larger diameter than the small-diameter protruding portion 16. In addition, the second abutting portion 28 is in a state where the engaging projection 24 abuts against the stop ring 3 (the state shown in FIG. 1), and is closer to the first facing surface 15 than the first abutting portion 17. It is arranged to be located in.
[0015]
The seal member 6 is disposed between the first facing surface 15 and the second facing surface 25. The seal member 6 is made of a metal such as steel or other material having elasticity and fire resistance, and is formed as a thin ring body. The inner diameter of the seal member 6 is substantially the same as the outer diameter of the fitting portion 13 and is externally inserted into the fitting portion 13. The outer diameter of the seal member 6 is larger than that of the second contact portion 28. Both end surfaces of the seal member 6 are flat surfaces orthogonal to the axis. Therefore, both end surfaces of the seal member 6 are orthogonal to the axis L in a natural state where no external force acts on the seal member 6.
[0016]
As described above, since the second contact portion 28 is located on the first facing surface 15 side with respect to the first contact portion 17, the right end surface and the left end surface of the seal member 6 are the first, It abuts against the second contact portions 17 and 28, respectively. In addition, the right end surface of the seal member 6 abuts on the first abutting portion 17 on the inner peripheral side, and the left end surface of the seal member 6 is closer to the outer peripheral side than the abutting portion between the right end surface and the first abutting portion 17. 2 Since it abuts against the contact portion 28, the seal member 6 is elastically deformed in the direction of the axis L. In this case, the seal member 6 has a first contact portion 17 in the radial direction where D is the distance between the second contact portion 28 and the first contact portion 17 and T is the thickness of the seal member 6. And the second contact portion are elastically deformed in the direction of the axis L by (D + T). Due to the elastic restoring force accompanying this elastic deformation, both end faces of the seal member 6 are brought into pressure contact with the first and second contact portions 17 and 28 in an annular manner. Thereby, the space between the first and second opposing surfaces 15 and 25 is hermetically sealed by the seal member 6.
[0017]
When connecting the gas pipe 1 and the joint 2, as shown in FIG. 3, the stop ring 3 and the seal members 4, 5, 6 are previously attached to predetermined portions of the gas pipe 1. Then, the gas pipe 1 is inserted into the joint 2 from the small diameter portion 12 side from the fitting hole portion 22 side. When the gas pipe 1 is inserted to a predetermined position, the fitting portion 13 is fitted into the fitting hole portion 22. Thereafter, when the gas pipe 1 is further inserted, the inclined surface 24 a of the engaging protrusion 24 hits the stop ring 3. When the gas pipe 1 is further inserted into the joint 2 in this state, the diameter of the stop ring 3 is reduced by the inclined surface 24a. Finally, as shown in FIG. 4, the inner peripheral surface of the engaging protrusion 24 is fitted to the outer peripheral surface of the stop ring 3. When the gas pipe 1 is further inserted into the joint 2, the tip surface of the large-diameter protruding portion 27 abuts against the seal member 6. At this time, the left end of the inner peripheral surface of the engagement protrusion 24 is fitted to the right end of the outer peripheral surface of the stop ring 3 by a distance (D + T). Therefore, when the gas pipe 1 is further inserted from the state by the distance (D + T) with respect to the joint 2, the engagement protrusion 24 passes from the stop ring 3 to the right. As a result, the diameter of the stop ring 3 is increased, and the engagement protrusion 24 hits the right end surface of the stop ring 3. As a result, the joint 2 is prevented from coming off to the left with respect to the gas pipe 1. In addition, in a state where the engagement protrusion 24 is in contact with the stop ring 3, the seal member 6 is elastically deformed by the distance (D + T) in the direction of the axis L, so that the seal member 6 is joined by its own elasticity. 2 is urged to the left, and the engagement protrusion 24 is kept in contact with the stop ring 3. Thereby, the gas pipe 1 and the joint 2 are connected so as to be almost immovable in the direction of the axis L.
[0018]
In the gas pipe sealing structure configured as described above, since both end faces of the seal member 6 are flat, the width dimension can be easily made highly accurate. Therefore, variation in contact pressure between the seal member 6 and the first and second contact portions 17 and 28 can be suppressed to a small value. Moreover, since the seal member 6 can easily improve the width accuracy, it can be manufactured at a much lower cost than when a disc spring-like seal member having the same width accuracy is manufactured. it can. Therefore, the connection cost between the gas pipe and the joint can be reduced.
[0019]
FIG. 5 shows another embodiment of the present invention. In this embodiment, a shielding protrusion 29 that protrudes toward the first facing surface 15 is formed in an annular shape on the outer peripheral portion of the tip surface of the large-diameter protrusion 27. The inner diameter of the shielding protrusion 29 is larger than the outer diameter of the seal member 6. The projection amount of the shielding projection 29 (the length in the direction of the axis L) is set to a length sufficient to cover the seal member 6. Therefore, the sealing member 6 can be made invisible from the outside, thereby improving the aesthetic appearance. Other configurations are the same as those in the above embodiment.
[0020]
In addition, this invention is not limited to said embodiment, It can change suitably.
For example, in the above-described embodiment, the small-diameter protruding portion 16 and the first contact portion 17 are formed on the first opposing surface 15 of the gas pipe 1, while the large-diameter protruding on the second opposing surface 25 of the joint 2. The portion 27 and the second contact portion 28 are formed, and a large-diameter protruding portion that protrudes toward the second opposing surface 25 is formed on the outer peripheral portion of the first opposing surface 15, and the large-diameter protruding portion A second abutting portion is formed at a corner portion on the inner peripheral side of the inner surface, a small-diameter protruding portion protruding toward the first opposing surface 15 is formed on the inner peripheral portion of the second opposing surface 25, and the small-diameter protruding portion You may form a 1st contact part in the corner | angular part of the outer peripheral side.
In the above-described embodiment, the second contact portion 28 is moved in the direction of the axis L by overlapping the tip of the large diameter projection 27 and the tip of the small diameter projection 16 in the direction of the axis L. The first abutting portion 17 is positioned closer to the first facing surface 15, but the second abutting portion is disposed away from the first abutting portion with respect to the first facing surface 15, and the direction of the axis L In this case, a gap may be formed between the first contact portion 17 and the second contact portion 28. However, the gap in the direction of the axis L is made smaller than the thickness T of the seal member 6. In this case, when the gap in the direction of the axis L is I and the thickness of the seal member 6 is T, the seal member 6 abuts against the first and second contact surfaces 17 and 28. It is elastically deformed in the direction of the axis L by the length (TI).
[0021]
【The invention's effect】
As described above, according to the present invention, the variation in the contact pressure between the seal member and the first and second contact portions can be reduced, thereby improving the sealing performance between the first and second opposing surfaces. The effect that it can suppress in a fixed range and can connect gas pipes cheaply is acquired.
[Brief description of the drawings]
FIG. 1 is a partially omitted cross-sectional view showing an embodiment of the present invention.
FIG. 2 is an enlarged view of an X circle part in FIG. 1;
FIG. 3 is a partially omitted cross-sectional view showing a state before connecting a gas pipe and a joint.
FIG. 4 is a partially omitted cross-sectional view showing a state in which a gas pipe and a joint are connected to each other.
FIG. 5 is a partially omitted cross-sectional view showing another embodiment of the present invention.
[Explanation of symbols]
1 Gas pipe 2 Joint (gas pipe)
6 Seal member 15 First facing surface (facing surface)
17 1st contact part 25 2nd opposing surface (opposing surface)
28 Second contact portion

Claims

Each of the fitting portions that are rotatably fitted to the pair of gas pipes is formed with an opposing surface that faces the axial direction of the fitting portion in an annular shape centering on the axis, and between the two opposing surfaces. In a gas pipe sealing structure in which an elastically deformable annular seal member made of a refractory material is provided, and between the two opposing surfaces is sealed by the seal member,
Both end surfaces of the seal member are flat surfaces orthogonal to the axis, and a first abutting portion projecting toward the other facing surface is formed in one of the two facing surfaces, and the one facing surface is disposed on the other facing surface. A second abutting portion projecting to the opposite surface side of the seal member is formed in an annular shape, and the seal member is elastically deformed in the axial direction. And a gas pipe characterized in that the second abutting portion is brought into pressure contact with the outer peripheral side of the other end surface of the seal member, whereby the gap between the two opposing surfaces is sealed by the seal member. Sealing structure.

The first and second contact portions are arranged such that the first contact portion is located on the other facing surface side in the axial direction with respect to the second contact portion, thereby the seal member 2. The gas pipe according to claim 1, wherein the first and second contact portions are pressed into contact with one end surface and the other end surface of the seal member in a state where the first elastic member is elastically deformed in the axial direction. Sealing structure.

The first and second abutting portions are arranged such that a gap is formed between them in which the gap in the axial direction is smaller than the thickness of the sealing member, whereby the sealing member is elastically deformed in the axial direction. 2. The gas pipe sealing structure according to claim 1, wherein the first and second contact portions are pressed and brought into contact with one end surface and the other end surface of the seal member in a state where the first and second contact portions are pressed.