JPH0326298B2 - - Google Patents

Description

【発明の詳細な説明】 この発明はガス供給路の途中に設けるガス自動
遮断装置に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic gas shutoff device provided in the middle of a gas supply path.

この種の装置として、例えば第１図に開通状
態、第２図に遮断状態を示す先行技術が発明され
た。これは、ガス供給路の途中にあつて、軸駆動
ばね１３の作用で遮断傾向をもち、遮断標識１４
を押し下げる外部操作で開通可能な遮断弁１８
と、遮断弁の下流に連通している供給圧室２０
と、可動膜１９で供給圧室２０と隔絶し平常は定
圧力源例えば大気に連通している基準圧室２１
と、可動膜１９を供給圧室２０の方向に附勢して
いる整圧附勢手段２５と、可動膜１９に連動して
それが基準圧室２１の方向の極限位置（第１図）
とその近辺とを含む範囲にあるときに限り遮断弁
１８の開通から遮断への変化を阻止する遮断阻止
手段３４とをもつものである。 As this type of device, for example, a prior art has been invented which shows an open state in FIG. 1 and a closed state in FIG. This is located in the middle of the gas supply path and has a tendency to shut off due to the action of the shaft drive spring 13.
Shutoff valve 18 that can be opened by external operation by pushing down
and a supply pressure chamber 20 communicating downstream of the shutoff valve.
and a reference pressure chamber 21 which is separated from the supply pressure chamber 20 by a movable membrane 19 and normally communicates with a constant pressure source, for example, the atmosphere.
, and the pressure regulation urging means 25 which urges the movable membrane 19 in the direction of the supply pressure chamber 20, and the movable membrane 19 is linked to move it to the extreme position in the direction of the reference pressure chamber 21 (FIG. 1).
The shutoff prevention means 34 prevents the shutoff valve 18 from changing from opening to shutoff only when the shutoff valve 18 is in a range including and the vicinity thereof.

この先行技術について以下により詳しく説明す
る。 This prior art will be explained in more detail below.

器体１はガス供給路の部分をなし、ガスを入口
２から出口３に導き、途中に大きな上向き開口を
設けこれに蓋体４を重ねて気密的に塞いである。
前記開口の中心直下で入口２との間に弁座孔５を
設け、その下端に下向きの遮断弁座６を設けてあ
る。 The container body 1 forms a part of a gas supply path, and guides gas from an inlet 2 to an outlet 3, and has a large upward opening in the middle, and a lid 4 is placed over the opening to seal it airtightly.
A valve seat hole 5 is provided directly below the center of the opening and between the valve seat hole 5 and the inlet 2, and a downwardly facing cutoff valve seat 6 is provided at the lower end of the valve seat hole 5.

蓋体４に弁座孔５と同心的に弁座孔５の近辺ま
で延長しかつ上下方向に内外を貫通する貫通孔を
もつ案内筒７を気密的に固着してあつて、その貫
通孔に上下に突出した弁駆動軸８をＯリング９で
気密を保ちつつ上下往復自在に嵌合してある。 A guide tube 7 having a through hole that extends concentrically with the valve seat hole 5 to the vicinity of the valve seat hole 5 and passes through the inside and outside in the vertical direction is airtightly fixed to the lid body 4. A vertically protruding valve drive shaft 8 is fitted with an O-ring 9 so as to be able to reciprocate vertically while maintaining airtightness.

弁駆動軸８の下端に遮断弁座６の下方に相対し
て遮断弁体１０を、遮断弁座６との完全遮断的接
触を容易にするため、接触姿勢に対し若干範囲だ
け傾斜自在なように支持している。即ち、弁駆動
軸８の下端に球体１１を固着し、遮断弁体１０に
その上流側と隔絶し上方から進入した前記球体１
１を可動的に包む空洞１２を設けてある。 The cutoff valve body 10 is placed at the lower end of the valve drive shaft 8 opposite to the lower side of the cutoff valve seat 6 so that it can be tilted within a certain range relative to the contact position in order to facilitate complete cutoff contact with the cutoff valve seat 6. I support it. That is, a sphere 11 is fixed to the lower end of the valve drive shaft 8, and the sphere 1 enters the cutoff valve body 10 from above, isolated from the upstream side thereof.
1 is provided with a cavity 12 movably enclosing it.

弁駆動軸８の上端に、案内筒７との間に軸駆動
ばね１３を挾んで赤色の遮断標識１４をねじこ
み、遮断弁体１０が遮断弁座６に接近する方向に
附勢してある。遮断標識１４を囲んで蓋体４に上
向き延長部１５を設け、遮断弁体６に対し遮断弁
体１０が接している閉止状態（第２図）では遮断
標識１４が延長部１５の上方に現れ、遮断標識１
４を延長部１５に殆んどかくれるまで押し下げる
と遮断弁座６から遮断弁体１０が十分に離れる
（第１図）。 A red shutoff mark 14 is screwed into the upper end of the valve drive shaft 8 with a shaft drive spring 13 interposed between it and the guide cylinder 7, and the shutoff valve body 10 is biased in the direction toward the shutoff valve seat 6. An upwardly extending portion 15 is provided on the lid body 4 surrounding the cutoff mark 14, and the cutoff mark 14 appears above the extension portion 15 in the closed state (FIG. 2) in which the cutoff valve body 10 is in contact with the cutoff valve body 6. , block sign 1
4 until it is almost hidden by the extension 15, the shutoff valve body 10 is sufficiently separated from the shutoff valve seat 6 (FIG. 1).

現れた状態の遮断標識１４を保護するため、延
長部１５の上端に着脱自在に透明覆１６をねじこ
み、透明覆１６には内部圧力を大気圧に等しくす
るための内外貫通孔１７を設け、内外貫通孔１７
は屋外設置状態での雨水の進入を防ぐために内方
に向い斜め上向きしてある。 In order to protect the exposed state of the cutoff sign 14, a transparent cover 16 is removably screwed onto the upper end of the extension part 15, and the transparent cover 16 is provided with an inner and outer through hole 17 to equalize the internal pressure to atmospheric pressure. Through hole 17
is oriented inward and diagonally upward to prevent rainwater from entering when installed outdoors.

遮断弁座６と遮断弁体１０とは、ガス供給路の
途中にあつて遮断傾向をもち外部操作で開通可能
な遮断弁１８を構成する。 The shutoff valve seat 6 and the shutoff valve body 10 constitute a shutoff valve 18 that is located in the middle of the gas supply path, has a tendency to shut off, and can be opened by external operation.

次に、器体１に蓋体４を重ねる部分にパツキン
を兼ねる可動膜１９を挾んで、器体１と蓋体４と
の間の空間を器体１の側にあつて出口３に連通し
た供給圧室２０と蓋体４の間にあつて平常は定圧
力源としての大気に連通した基準圧室２１とに区
分してある。 Next, a movable membrane 19, which also serves as a gasket, is sandwiched between the part where the lid 4 is placed on the container 1, and the space between the container 1 and the lid 4 is placed on the side of the container 1 and communicated with the outlet 3. It is divided into a reference pressure chamber 21 located between the supply pressure chamber 20 and the lid 4 and normally communicating with the atmosphere as a constant pressure source.

可動膜１９にその周辺部分を残して基準圧室２
１の側に剛性の膜板２２を当て、中心部を貫通す
る膜ボス２３にナツト２４をねじこんで膜板２２
と可動膜１９とを互に固定し、膜板２２と膜ボス
２３との間の気密を接着材で保持してある。 The reference pressure chamber 2 is formed by leaving the surrounding area on the movable membrane 19.
Place a rigid membrane plate 22 on the side of 1, screw the nut 24 into the membrane boss 23 that passes through the center, and attach the membrane plate 22.
and the movable membrane 19 are fixed to each other, and the airtightness between the membrane plate 22 and the membrane boss 23 is maintained with an adhesive.

膜板２２は蓋体４の下面との間に挾んだ整圧ば
ね２５で常に供給圧室２０の方向に附勢されてい
る。膜ボス２３は中空貫通孔をもち、案内筒７の
外周に軸封手段２６で気密を保ちつつ上下往復自
在に嵌合している。 The membrane plate 22 is always urged toward the supply pressure chamber 20 by a pressure regulating spring 25 interposed between the membrane plate 22 and the lower surface of the lid 4. The membrane boss 23 has a hollow through hole, and is fitted onto the outer periphery of the guide cylinder 7 so as to be able to reciprocate up and down while maintaining airtightness with a shaft sealing means 26.

膜板２２及びこれに伴う可動膜１９、膜ボス２
３、ナツト２４などの可動部材は、第１図に示す
ように膜板２２の周縁が蓋体４の内面に当る基準
圧室２１の方向の極限位置と、第２図に示すよう
に案内筒７の下端にねじこんだストツパ２７に膜
ボス２３の下端が当る供給圧室２０の方向の極限
位置との間を往復可能である。 Membrane plate 22 and accompanying movable membrane 19, membrane boss 2
3. The movable members such as the nut 24 are placed at the extreme position in the direction of the reference pressure chamber 21, where the peripheral edge of the membrane plate 22 hits the inner surface of the lid body 4 as shown in FIG. 1, and at the extreme position in the direction of the reference pressure chamber 21 as shown in FIG. It is possible to reciprocate between an extreme position in the direction of the supply pressure chamber 20, where the lower end of the membrane boss 23 hits a stopper 27 screwed into the lower end of the membrane boss 7.

案内筒７において、Ｏリング９と軸封手段２６
との何れから見ても供給圧室２０の側に、内外両
面間を中心線に直交する方向に貫通し、その肉厚
の1.5〜２倍程度の直径をもつ鋼球２８を可動的
に保持する２個の球孔２９を設けてある。 In the guide cylinder 7, the O-ring 9 and the shaft sealing means 26
A steel ball 28 is movably held on the side of the supply pressure chamber 20 when viewed from either side, penetrating between the inner and outer surfaces in a direction perpendicular to the center line, and having a diameter of about 1.5 to 2 times the wall thickness. Two ball holes 29 are provided.

弁駆動軸８の外周には、第１図に示すように遮
断弁体１０が遮断弁座６から最も離れた開通位置
にあるとき鋼球２８に正対する部分を小径にして
球逃げ溝３０を構成してある。球逃げ溝３０は鋼
球２８を案内筒７の外周まで内方に押し込んだと
き内周から突出する部分を収容するに十分な形状
をもち、下側面３１を斜面として、弁駆動軸８の
閉止方向変位即ち遮断弁体１０が遮断弁座６に接
近する方向の変位により鋼球２８を外方に押し戻
す方向に駆動するようにしてある。 As shown in FIG. 1, a ball relief groove 30 is formed on the outer periphery of the valve drive shaft 8 so that the portion that directly faces the steel ball 28 when the shutoff valve body 10 is in the open position farthest from the shutoff valve seat 6 has a small diameter. It is configured. The ball escape groove 30 has a shape sufficient to accommodate the portion that protrudes from the inner periphery when the steel ball 28 is pushed inward to the outer periphery of the guide cylinder 7, and has a lower surface 31 as a slope to close the valve drive shaft 8. The steel ball 28 is driven in the direction of pushing back outward by the directional displacement, that is, the displacement in the direction in which the shutoff valve body 10 approaches the shutoff valve seat 6.

他方、膜ボス２３の内面にも、第１図に示す基
準圧室２１の方向の極限位置から第２図に示す膜
ボス２３の下端がストツパ２７に接する供給圧室
２０の方向の極限位置までのうち基準圧室２１方
向の極限位置とその近辺とを除く間において鋼球
２８と正対する範囲を大径として球逃げ溝３２を
構成してある。球逃げ溝３２は鋼球２８を案内筒
７の内周まで押しだしたとき外周から突出する部
分を収容するに十分な形状をもち、下側面３３を
斜面として、膜ボス２３の基準圧室２１の方向の
極限位置に至る変位により鋼球２８を内方に押し
込む方向に駆動するようにしてある。 On the other hand, the inner surface of the membrane boss 23 also extends from the extreme position in the direction of the reference pressure chamber 21 shown in FIG. The ball relief groove 32 is configured such that the area facing the steel ball 28 has a large diameter except for the extreme position in the direction of the reference pressure chamber 21 and the vicinity thereof. The ball escape groove 32 has a shape sufficient to accommodate the portion that protrudes from the outer periphery when the steel ball 28 is pushed out to the inner periphery of the guide cylinder 7, and has a lower surface 33 as an inclined surface to accommodate the part of the reference pressure chamber 21 of the membrane boss 23. The steel ball 28 is driven in the direction in which the steel ball 28 is pushed inward by the displacement reaching the extreme position in the direction.

以上２８〜３３は、可動膜１９に連動してそれ
が基準圧室２１の方向の極限位置とその近辺とよ
りなる範囲にあるときに限り遮断弁１８の開通か
ら遮断への変化を阻止する遮断阻止手段３４を構
成する。 The above 28 to 33 are interlocked with the movable membrane 19 to prevent the shutoff valve 18 from changing from open to shut off only when the movable membrane 19 is in a range consisting of the extreme position in the direction of the reference pressure chamber 21 and its vicinity. This constitutes a blocking means 34.

以上に述べた装置において、基準圧室２１を定
圧力源としての大気に連通させて使用するとき
は、供給圧室２０の圧力が一定値以下になつたと
き遮断弁１８が自動的に遮断する圧力応動型のガ
ス自動遮断装置として作動する。 In the device described above, when the reference pressure chamber 21 is used in communication with the atmosphere as a constant pressure source, the cutoff valve 18 automatically shuts off when the pressure in the supply pressure chamber 20 falls below a certain value. Operates as a pressure-responsive automatic gas shutoff device.

即ち、設置前は、第２図に示すように、可動膜
１９などは供給圧室２０の方向の極限位置にあ
り、遮断弁１８は遮断状態にあり、これを設置す
ると入口２から遮断弁座６まではガス圧がかかる
がその他の部分は大気圧のままである。 That is, before installation, as shown in FIG. 2, the movable membrane 19 and the like are at the extreme position in the direction of the supply pressure chamber 20, and the cutoff valve 18 is in the cutoff state. Gas pressure is applied up to 6, but the other parts remain at atmospheric pressure.

透明覆１６を外して遮断標識１４を十分に押し
下げその状態を維持すると、供給圧室２０以降に
もガスが進入してガス圧が上昇し、可動膜１９が
上昇して第１図に示すように鋼球２８が弁駆動軸
８の球逃げ溝３０と案内筒７の内周とに挾まれた
状態となる。 When the transparent cover 16 is removed and the blocking sign 14 is pushed down sufficiently and maintained in that state, gas enters the supply pressure chamber 20 and beyond, the gas pressure rises, and the movable membrane 19 rises as shown in FIG. The steel ball 28 is now sandwiched between the ball escape groove 30 of the valve drive shaft 8 and the inner periphery of the guide tube 7.

この状態で遮断標識１４から手を離すと、鋼球
２８により弁駆動軸８の上昇を阻止されるため、
遮断弁１８は開いた状態を維持する。 If you let go of the shutoff sign 14 in this state, the steel ball 28 will prevent the valve drive shaft 8 from rising.
Shutoff valve 18 remains open.

この状態で使用中、何らかの原因で供給圧室２
０の圧力が低下すると、可動膜１９が下降し、第
２図に示すように、鋼球２８を膜ボス２３の球逃
げ溝３２に押し込んで弁駆動軸８が上昇し、遮断
弁１８は遮断状態となり、遮断標識１４が現れ
る。 During use in this condition, for some reason the supply pressure chamber 2
When the pressure at 0 decreases, the movable membrane 19 descends, and as shown in FIG. state, and a cutoff sign 14 appears.

この先行技術では、更に、第１図に示すよう
に、基準圧室２１の連通先を定圧力源（この場合
では大気）か供給圧室２０かに択一的に切換える
ための切換弁３５を具えている。 This prior art further includes a switching valve 35 for selectively switching the communication destination of the reference pressure chamber 21 between a constant pressure source (in this case, the atmosphere) and the supply pressure chamber 20, as shown in FIG. It is equipped with

即ち、蓋体４に、基準圧室２１に連通する空洞
３６を設け、空洞３６を貫通して軸方向に往復自
在の切換弁軸３７を設け、空洞３６の両端に切換
弁軸３７が十分な隙間を保つて貫通する貫通孔３
８，３９を設け、下側貫通孔３８を供給圧室２０
に上側貫通孔３９を大気に連通してある。空洞３
６の両端に貫通孔３８，３９をそれぞれ囲んで空
洞３６内に向う切換弁座４０，４１を設け、空洞
３６内において切換弁軸３７に切換弁座４０，４
１にそれぞれ正対し切換弁軸３７の軸方向往復に
より相反的に遮断開通する切換弁体４２，４３を
固着してある。 That is, the lid body 4 is provided with a cavity 36 that communicates with the reference pressure chamber 21, a switching valve shaft 37 is provided that passes through the cavity 36 and is reciprocatable in the axial direction, and the switching valve shaft 37 is provided at both ends of the cavity 36. Through hole 3 that penetrates while maintaining a gap
8 and 39, and the lower through hole 38 is connected to the supply pressure chamber 20.
An upper through hole 39 is connected to the atmosphere. cavity 3
Switching valve seats 40 and 41 are provided at both ends of the switching valve shaft 37 to surround the through holes 38 and 39, respectively, and facing into the cavity 36.
Switching valve bodies 42 and 43 are fixed to the switching valves 1 and 1, respectively, and are opened and closed in a reciprocal manner by reciprocating the switching valve shaft 37 in the axial direction.

切換弁軸３７は電磁鉄心４４に固着し、電磁鉄
心４４は復帰ばね４５により、切換弁体４３が空
洞３６従つて基準圧室２１を大気との連通を断つ
て供給圧室２０に連通させる方向に附勢されてい
て、コイル４６に通電すると、復帰ばね４５に抗
して切換弁体４３が下降し、基準圧室２１を大気
に連通させるようにしてある。 The switching valve shaft 37 is fixed to the electromagnetic core 44, and the electromagnetic core 44 is set in a direction in which the switching valve body 43 disconnects the cavity 36 and therefore the reference pressure chamber 21 from the atmosphere and connects it to the supply pressure chamber 20 by a return spring 45. When the coil 46 is energized and the coil 46 is energized, the switching valve body 43 is lowered against the return spring 45, thereby communicating the reference pressure chamber 21 with the atmosphere.

従つて、第１図に示すようにコイル４６に通電
した状態で使用すると基準圧室２１が大気に連通
しているので、供給ガス圧が一定以下に低下する
と作動する圧力応動型のガス自動遮断装置として
働くが、そのうえ、コイル４６の通電が換気扇の
電力供給の停止とともに停止するようにしておく
ときは、停電と同時に切換弁体４３が上昇して基
準圧室２１の圧力が供給圧室２０の圧力と等しく
なる結果整圧ばね２５により可動膜１９が供給圧
室２０の方向に変位し、供給圧室２０の圧力低下
の場合と同様に遮断弁１８が遮断する。 Therefore, when used with the coil 46 energized as shown in FIG. 1, the reference pressure chamber 21 is in communication with the atmosphere, so a pressure-responsive gas automatic shutoff is activated when the supply gas pressure drops below a certain level. In addition, when the coil 46 is configured to stop energizing when the power supply to the ventilation fan stops, the switching valve body 43 rises at the same time as the power outage, and the pressure in the reference pressure chamber 21 changes to the supply pressure chamber 20. As a result, the movable membrane 19 is displaced in the direction of the supply pressure chamber 20 by the pressure regulating spring 25, and the cutoff valve 18 is shut off in the same way as in the case of the pressure drop in the supply pressure chamber 20.

従つて、この先行技術の装置は、圧力応動型の
ほか、停電応動型のガス自動遮断装置として働
く。 This prior art device therefore works as a pressure-responsive as well as a power failure-responsive gas automatic shut-off device.

この先行技術では、遮断後の開通再開に際し遮
断標識１４を押し下げると、遮断弁１８を経て短
時間に多量のガスが下流に向つて流れるが、この
場合、下流のガス器具の入口栓に開通状態のもの
があつたり、凡ての入口栓が閉止状態にあつたと
してもそれに至る配管の漏洩個所が発見されない
まま残存していると、一時に多量のガスが外部に
放出される危険がありうる。 In this prior art, when the shutoff sign 14 is pushed down when restarting the line after the shutoff, a large amount of gas flows downstream through the shutoff valve 18 in a short period of time, but in this case, the inlet plug of the downstream gas appliance is in the open state. Even if something hits the pipe or all the inlet plugs are closed, if the leakage point in the piping leading to the leak remains undiscovered, there is a risk that a large amount of gas will be released to the outside at once. .

この発明は、このような危険を最小限にとどめ
ることができるガス自動遮断装置の実現を目的と
する。 The object of the present invention is to realize an automatic gas shutoff device that can minimize such risks.

第１〜２図でそれぞれ開通状態及び遮断状態を
説明した先行技術のものに、第３〜５図でそれぞ
れ開通状態、遮断状態、及び開通操作直後状態を
示すような部分的変更を加えてなる実施例につい
て、この発明の構成と作用とを説明する。 This is obtained by partially modifying the prior art in which the opening state and the blocking state are explained in FIGS. 1 to 2, respectively, so that the opening state, the blocking state, and the state immediately after the opening operation are shown in FIGS. 3 to 5, respectively. The structure and operation of the present invention will be explained with reference to embodiments.

第３〜５図において、４７は、遮断弁１８の部
分である遮断弁孔５の下流で供給圧室２０の上流
に設けた上向きの閉止弁座、４８は可動膜１９と
膜板２２とを互に固定するため膜ボス２３にねじ
こんであるナツト２４の下面に、閉止弁座４７に
相対して固着した閉止弁体であつて、閉止弁体４
８は閉止弁座４７に対し、可動膜１９の供給圧室
２０の方向の極限位置で接触して閉止作用をす
る。即ち、閉止弁座４７と閉止弁体４８とは、供
給圧室２０の圧力低下時の可動膜１９の下向によ
つて閉止する低下時閉止弁４９を構成する。遮断
弁座６と閉止弁座４７との間の弁座孔５の空間
は、絞り通路５０を介して供給圧室２０に連通さ
せてある。 In FIGS. 3 to 5, reference numeral 47 indicates an upward closing valve seat provided downstream of the cutoff valve hole 5 and upstream of the supply pressure chamber 20, which is a part of the cutoff valve 18, and 48 indicates the movable membrane 19 and the membrane plate 22. A shutoff valve body is fixed to the lower surface of a nut 24 that is screwed into a membrane boss 23 in order to fix each other, facing a shutoff valve seat 47.
8 contacts the closing valve seat 47 at the extreme position of the movable membrane 19 in the direction of the supply pressure chamber 20 to perform a closing action. That is, the shutoff valve seat 47 and the shutoff valve body 48 constitute a drop shutoff valve 49 that is closed by the downward movement of the movable membrane 19 when the pressure in the supply pressure chamber 20 drops. The space of the valve seat hole 5 between the cutoff valve seat 6 and the closing valve seat 47 is communicated with the supply pressure chamber 20 via the throttle passage 50 .

このように構成してあるから、第４図に示す遮
断弁の遮断状態において第５図に示すように遮断
標識１４を押し下げ、遮断弁座６に対して遮断弁
体１０を開く開通操作をしたときは、弁座孔５の
ガス圧は直ちに上流側と同一になるが、低下時遮
断弁４９より下流の圧力は絞り通路５０を通つて
流入するガスにより徐々に上昇する。この流入量
を、例えば60／ｈ程度の小流量にとどめるよう
に絞り通路５０の断面積を定めておくときは、こ
のガス自動遮断装置の下流での全部の漏洩量が60
／ｈを越えない限り供給圧室２０の圧力は上昇
せず、可動膜１９は第４図の極限位置のままで低
下時閉止弁４９は閉止状態を続ける。従つて一時
に多量の生ガスが外部に流出するおそれはない。
この状態で遮断標識１４から手を離すと、第４図
の遮断状態に戻る。 With this structure, when the shutoff valve is in the shutoff state shown in FIG. 4, the shutoff sign 14 is pushed down as shown in FIG. 5, and the opening operation is performed to open the shutoff valve body 10 against the shutoff valve seat 6. At this time, the gas pressure in the valve seat hole 5 immediately becomes the same as that on the upstream side, but the pressure downstream of the drop cutoff valve 49 gradually increases due to the gas flowing in through the throttle passage 50. When the cross-sectional area of the throttle passage 50 is determined so as to keep this inflow amount to a small flow rate of, for example, about 60/h, the total leakage amount downstream of this automatic gas shutoff device is 60/h.
The pressure in the supply pressure chamber 20 does not rise unless the pressure exceeds /h, the movable membrane 19 remains at the extreme position shown in FIG. 4, and the drop shutoff valve 49 continues to be closed. Therefore, there is no risk that a large amount of raw gas will leak outside at once.
When the hand is released from the cutoff sign 14 in this state, the state returns to the cutoff state shown in FIG. 4.

下流での漏洩が僅少なときは、供給圧室２０の
圧力は徐々に上昇し、可動膜１９が整圧ばね２５
に抗して上昇するに及んで低下時閉止弁４９が開
き、直ちに第３図に示すような開通状態となる。
この状態で遮断標識１４から手を離しても、第３
図の開通状態を維持する。 When the leakage downstream is small, the pressure in the supply pressure chamber 20 gradually increases, and the movable membrane 19 is moved by the pressure regulating spring 25.
As it rises against the pressure, the lowering shutoff valve 49 opens and immediately enters the open state as shown in FIG.
Even if you let go of the cutoff sign 14 in this state, the third
Maintain the open state of the diagram.

この発明によると、先行技術のものに、低下時
閉止弁４９及び絞り通路５０の追加という僅少の
変更を施すだけで、再開通時の生ガスの多量放出
という前記の危険を除くことができるからきわめ
て有効である。 According to the present invention, the above-mentioned danger of releasing a large amount of raw gas at the time of re-opening can be eliminated by making a slight change to the prior art, such as adding the drop shutoff valve 49 and the throttle passage 50. Extremely effective.

【図面の簡単な説明】[Brief explanation of drawings]

第１図と第２図とは、先行技術の装置のそれぞ
れ開通状態と遮断状態とを示す断面図、第３図、
第４図、第５図は、この発明の一実施例につい
て、第１〜２図の先行技術の装置に対する変更部
分の、それぞれ開通状態、遮断状態、及び開通操
作直後の状態を示す断面図である。 ７……案内溝、８……弁駆動軸、１８……遮断
弁、１９……可動膜、２０……供給圧室、２１…
…基準圧室、２３……膜ボス、２５……整圧附勢
手段、２８……球（鋼球）、２９……球孔、３０，
３２……球逃げ溝、３１，３３……一側面（下側
面）、３４……遮断阻止手段、４９……低下時閉
止弁、５０……絞り通路。 1 and 2 are cross-sectional views of the prior art device in open and closed states, respectively; FIG. 3;
FIGS. 4 and 5 are cross-sectional views of an embodiment of the present invention showing a modified portion of the prior art device shown in FIGS. 1 and 2 in an open state, a closed state, and a state immediately after the opening operation, respectively. be. 7... Guide groove, 8... Valve drive shaft, 18... Shutoff valve, 19... Movable membrane, 20... Supply pressure chamber, 21...
...Reference pressure chamber, 23...Membrane boss, 25...Pressure regulating means, 28...Ball (steel ball), 29...Ball hole, 30,
32...Ball relief groove, 31, 33...One side (lower side), 34...Block prevention means, 49...Lowering shut-off valve, 50... Throttle passage.

Claims (1)

【特許請求の範囲】[Claims] １ ガス供給路の途中にあつて遮断傾向をもち外
部操作で開通可能な遮断弁１８と、遮断弁１８の
下流に連通している供給圧室２０と、可動膜１９
で供給圧室２０と隔絶し平常は定圧力源に連通し
ている基準圧室２１と、可動膜１９を供給圧室２
０の方向に附勢している整圧附勢手段２５と、上
下方向の筒状をなす固定の案内筒７と、この案内
筒７に上下往復自在に嵌入されて遮断弁１８を駆
動する弁駆動軸８と、案内筒７の外側に上下往復
自在に嵌合しかつ可動膜１９に固着された膜ボス
２３と、前記案内筒７の内外両面間を中心線に直
交する方向に貫通する球孔２９に可動的に保持さ
れた球２８とをもち、遮断弁１８が開通位置にあ
るとき球２８と正対する弁駆動軸８の外周部分を
小径として球逃げ溝３０を構成すると共に、この
球逃げ溝３０の一側面３１を弁駆動軸８の閉止方
向変位により球２８を案内筒７の外方に押し戻す
方向の斜面となし、前記膜ボス２３はその基準圧
室２１方向の極限位置とその近辺とを除く間にお
いて球２８と正対する内周部分を大径として球逃
げ溝３２を構成すると共に、この球逃げ溝３２の
一側面３３を膜ボス２３の基準圧室２１方向の極
限位置に至る変位により球２８を案内筒７の内方
に押し込む方向の斜面となし、更に、遮断弁１８
の直接下流と供給圧室２０との間に、可動膜１９
に連動してその供給圧室２０の方向の極限位置で
閉止する低下時閉止弁４９を設け、遮断弁１８の
直接下流と低下時閉止弁４９との間の空間を絞り
通路５０を介して供給圧室２０に連通させてな
る、ガス自動遮断装置。1. A cutoff valve 18 that is located in the middle of the gas supply path and has a tendency to shut off and can be opened by external operation, a supply pressure chamber 20 that communicates downstream of the cutoff valve 18, and a movable membrane 19.
The reference pressure chamber 21, which is isolated from the supply pressure chamber 20 and normally communicates with a constant pressure source, and the movable membrane 19 are connected to the supply pressure chamber 2.
A pressure regulation and energizing means 25 that is energized in the 0 direction, a fixed guide tube 7 that is cylindrical in the vertical direction, and a valve that is fitted into the guide tube 7 so as to be able to reciprocate up and down to drive the cutoff valve 18. A drive shaft 8, a membrane boss 23 that fits on the outside of the guide tube 7 in a vertically reciprocating manner and is fixed to the movable membrane 19, and a ball that penetrates between the inner and outer surfaces of the guide tube 7 in a direction perpendicular to the center line. A ball 28 is movably held in the hole 29, and the outer circumferential portion of the valve drive shaft 8 that directly faces the ball 28 when the shutoff valve 18 is in the open position forms a ball escape groove 30 with a small diameter. One side surface 31 of the escape groove 30 is formed as an inclined surface that pushes the ball 28 back to the outside of the guide tube 7 when the valve drive shaft 8 is displaced in the closing direction, and the membrane boss 23 is located at its extreme position in the direction of the reference pressure chamber 21 and its maximum position. The ball relief groove 32 is formed by making the inner circumferential portion facing the ball 28 larger in diameter except for the vicinity thereof, and one side surface 33 of the ball relief groove 32 is positioned at the extreme position of the membrane boss 23 in the direction of the reference pressure chamber 21. The ball 28 is pushed into the guide cylinder 7 by the displacement thereof, and the shutoff valve 18
A movable membrane 19 is provided between directly downstream of the supply pressure chamber 20 and the supply pressure chamber 20.
A drop shutoff valve 49 is provided which closes at the extreme position in the direction of the supply pressure chamber 20 in conjunction with the supply pressure chamber 20, and the space between the drop shutoff valve 49 and the direct downstream of the cutoff valve 18 is supplied via the throttle passage 50. An automatic gas shutoff device that communicates with the pressure chamber 20.