JPS6059474B2 - Safety valve device in fluid circuit - Google Patents
Safety valve device in fluid circuitInfo
- Publication number
- JPS6059474B2 JPS6059474B2 JP5847277A JP5847277A JPS6059474B2 JP S6059474 B2 JPS6059474 B2 JP S6059474B2 JP 5847277 A JP5847277 A JP 5847277A JP 5847277 A JP5847277 A JP 5847277A JP S6059474 B2 JPS6059474 B2 JP S6059474B2
- Authority
- JP
- Japan
- Prior art keywords
- fluid
- pressure
- circuit
- relief valve
- piston
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Landscapes
- Safety Valves (AREA)
- Indication Of The Valve Opening Or Closing Status (AREA)
Description
【発明の詳細な説明】
本発明は、流体回路における安全弁装置、特に、流体圧
により作動される流体作動系とそれに作動流体を供給す
るための流体圧発生装置との間を接続する流体回路の途
中に、その回路内の流体圧が所定値以上に上昇すると開
弁して同回路内の流体を流体貯槽に還流させる逃し弁を
設けた形式のものに関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a safety valve device in a fluid circuit, particularly a fluid circuit that connects a fluid working system operated by fluid pressure and a fluid pressure generating device for supplying working fluid thereto. It relates to a type in which a relief valve is provided in the middle of the circuit, which opens when the fluid pressure in the circuit rises to a predetermined value or higher, and allows the fluid in the circuit to flow back to the fluid storage tank.
従来、上記形式の安全弁装置では、上記逃し弁以外に回
路内の流体圧の過度の上昇を抑える手段が何も設けられ
ていなかつたので、４ 逃し弁が万一故障により開弁不
能状態になつた場合には、回路内の流体圧が前記所定値
（開弁設定圧）以上に上昇してもその上昇を抑えること
ができず、流体圧発生装置が過負荷運転状態となり故障
し易い。Conventionally, in the above-mentioned type of safety valve device, other than the above-mentioned relief valve, there was no means for suppressing an excessive rise in fluid pressure in the circuit. In this case, even if the fluid pressure in the circuit rises above the predetermined value (valve opening set pressure), the rise cannot be suppressed, and the fluid pressure generating device is likely to be in an overload operating state and break down.
＠ 逃し弁が正常に機能している場合には、回路内の流
体圧が前記所定値を上下するたびに逃し弁が開閉される
ことになるから、その度重なる開閉のために、流体中の
固形成分や不純物が逃し弁の弁座部と弁体間に挟み込ま
れたり或いは弁座部を摩耗させたりし易くなり、そのた
め逃し弁の閉成が不完全となつて回路内の流体の一部が
常に流体貯槽側へリークしてしまう等の不都合を来たす
おそれがある。@ If the relief valve is functioning normally, it will open and close every time the fluid pressure in the circuit goes up and down above the predetermined value. Solid components and impurities can easily become trapped between the valve seat and valve body of the relief valve, or cause the valve seat to wear out, resulting in incomplete closure of the relief valve and a portion of the fluid in the circuit. There is a risk that inconveniences such as constant leakage to the fluid storage tank may occur.
以上４、＠の欠点があつた。Above 4, there are drawbacks of @.
本発明は、上記に鑑み提案されたもので、従来のものの
上記欠点をすべて解消し得る、構造簡単な、前記安全弁
装置を提供することを目的とし、その特徴とするところ
は、流体回路内の流体圧の上昇に応じてシリンダブロッ
ク等のケーシング内を移動する一個のピストンと：前記
流体回路内の流体圧が前記逃し弁の開弁設定圧よりも低
い第１の設定圧まで上昇したとき前記ピストンに連動し
て作動し、前記流体圧発生装置の作動を停止させる第１
のスイッチと；同流体圧が前記逃し弁の開弁設定圧より
も高い第２の設定圧まで上昇したとき前記ピストンに連
動して作動し、前記流体圧発生装置の作動を停止させる
第２のスイッチと；を備えていることにある。The present invention has been proposed in view of the above, and aims to provide the above-mentioned safety valve device which can eliminate all the above-mentioned drawbacks of the conventional devices and has a simple structure. a piston that moves within a casing of a cylinder block or the like in response to an increase in fluid pressure: when the fluid pressure in the fluid circuit rises to a first set pressure that is lower than the opening set pressure of the relief valve; a first actuator that operates in conjunction with the piston and stops the operation of the fluid pressure generating device;
a second switch that operates in conjunction with the piston and stops the operation of the fluid pressure generating device when the fluid pressure rises to a second set pressure higher than the valve opening set pressure of the relief valve; The reason is that it is equipped with a switch and;
以下図面により本発明の一実施例について説明すると、
ます第１図において、安全弁装置１は電源２に接続され
た電気回路３を有し、この電気回路３には流体圧発生装
置４と、常閉型の中間設定圧応動スイッチ５と、主スイ
ッチ６と、開状態となつたときに警報灯１１のような警
報器を作動する常閉型の上限設定圧反動スイッチ７とが
順次直列に接続されている。An embodiment of the present invention will be described below with reference to the drawings.
In FIG. 1, the safety valve device 1 has an electric circuit 3 connected to a power source 2, and this electric circuit 3 includes a fluid pressure generator 4, a normally closed intermediate setting pressure responsive switch 5, and a main switch. 6 and a normally closed upper limit set pressure reaction switch 7 which activates an alarm such as a warning light 11 when opened, are connected in series.
そして、流体圧発生装置４の流体出口と流体作動系９と
を接続する流体回路８の途中には安全弁１０が接続され
ている。第２図には第１図の安全弁装置１の要部がさら
に詳細に示されている。この第２図において、流体圧発
生装置４は流体貯蔵１２と、この流体貯槽１２に逆止弁
１３を介して接続されたポンプ１５と、このポンプ１５
に逆止弁１４、流路１７を介して接続された蓄圧器１８
とを有し、蓄圧器１８により圧力調整された流体は流路
１６，１９を経て液体圧により作動する種々の流体機械
を含む流体作動系９へ圧送されるようになつている。そ
し．て、流体圧発生装置４と流体作動系９とを接続する
流路１６，１９の途中からは流路２０が分岐しており、
この流路２０は、安全弁１０のシリンダブロック２１に
設けられた入口流路２２に接続されている。シリンダブ
ロック２１内において、入口流路２２からは流路２３が
分岐しており、この流路２３からはさらにそれぞれオリ
フィス２４，２６を途中に有する一対の流路２５，２７
が分岐している。A safety valve 10 is connected in the middle of the fluid circuit 8 that connects the fluid outlet of the fluid pressure generating device 4 and the fluid operating system 9. FIG. 2 shows the main parts of the safety valve device 1 shown in FIG. 1 in more detail. In FIG. 2, the fluid pressure generating device 4 includes a fluid storage 12, a pump 15 connected to the fluid storage tank 12 via a check valve 13, and a pump 15 connected to the fluid storage tank 12 via a check valve 13.
A pressure accumulator 18 connected via a check valve 14 and a flow path 17 to
The fluid whose pressure is regulated by the pressure accumulator 18 is forced to be sent through channels 16 and 19 to a fluid operating system 9 that includes various fluid machines operated by liquid pressure. stop. A flow path 20 branches off from the middle of the flow paths 16 and 19 connecting the fluid pressure generating device 4 and the fluid operation system 9.
This flow path 20 is connected to an inlet flow path 22 provided in the cylinder block 21 of the safety valve 10. Inside the cylinder block 21, a flow path 23 branches off from the inlet flow path 22, and from this flow path 23, a pair of flow paths 25, 27 each having orifices 24, 26 in the middle are formed.
is branching out.
シリンダブロック２１内にはシリンダ室２８・が形成さ
れており、このシリンダ室２８内に滑接自在に嵌入され
ているピストン２９はシリンダ室２８を前室Ａと後室Ｂ
とに区画している。そして前記流路２５，２７のうちの
一方の流路２５は前室Ａに連通していると）もに、他方
の流路２７は後室Ｂに連通している。ピストン２９は前
室Ａ側に突出する比較的小径の前部ピストンロッド３０
と、後室Ｂ側に突出する比較的大径の後部ピストンロッ
ド３１とを備え、前部ピストンロッド３０はシリンダブ
ロック２１内に穿設された滑接孔３３内にシール部材３
２を介して滑接自在に嵌入している。A cylinder chamber 28 is formed in the cylinder block 21, and a piston 29 that is slidably fitted into the cylinder chamber 28 divides the cylinder chamber 28 into a front chamber A and a rear chamber B.
It is divided into One of the channels 25 and 27 communicates with the front chamber A, and the other channel 27 communicates with the rear chamber B. The piston 29 has a relatively small diameter front piston rod 30 that protrudes toward the front chamber A side.
and a relatively large-diameter rear piston rod 31 that protrudes toward the rear chamber B side.
2 so that they can be slid into contact with each other.
そして、前部ピストンロッド３０の外周面上に形成され
た肩１部３４は滑接孔３３の内周面上に形成された肩部
３５に衝接するように構成されており、肩部３４と肩部
３５とが互いに協働してピストン２９のそれ以上の前進
を抑止することにより、流路２５は常に前室Ａに連通す
ることができるようになつている。前部ピストンロッド
３０の内部には、連通孔３７を介して逃し弁室３８と連
通する緩衝室３６が形成されており、この緩衝室３６内
には軸方向の貫通孔３９を有する緩衝ピストン４０が滑
接自在に嵌入されている。The shoulder 1 portion 34 formed on the outer circumferential surface of the front piston rod 30 is configured to abut against the shoulder portion 35 formed on the inner circumferential surface of the sliding contact hole 33. The shoulder portions 35 cooperate with each other to prevent the piston 29 from moving further, so that the flow path 25 can always communicate with the front chamber A. A buffer chamber 36 that communicates with a relief valve chamber 38 via a communication hole 37 is formed inside the front piston rod 30, and a buffer piston 40 having an axial through hole 39 is formed in the buffer chamber 36. is inserted so that it can be slidably connected.
この緩衝ピストン４０と一体的に形成されて前方へ突出
するロッド４１の先端部には逃し弁４２が形成されてい
る。逃し弁３８は弁座部４３を経て入口流路２２に連通
していると）もに、出口流路４５、流路４６を経て流体
貯槽１２とも連通している。そして、逃し弁室３８の後
壁と逃し弁４２の肩部との間には押圧ばね４４が介装さ
れており、この押圧ばね４４の押圧力により、逃し弁４
２は常時弁座部４３側へ押圧され、入口流路２２を通し
て予め設定された圧力以上の圧力を有する流体が導入さ
れたときにのみ、逃し弁４２が押圧ばね４４に抗して開
き、その流体を出口流路４５、流路４６を経て流体貯槽
１２へ還流するように構成されている。この際、緩衝ピ
ストン４０は、貫通孔３９を有することによつて、逃し
弁４２の急激な移動に対して緩衝作用を果たす。ピスト
ン２９の後部ピストンロッド３１はシール部材４７を介
してシリンダブロック２１の後壁を滑接自在に貫通して
おり、その後端部からさらに後方へー体的に延在する作
動杆４９に設けられた一対の係合爪５０，５１は常閉型
の中間設定圧応動スイッチ５の突子５２と係合している
。A relief valve 42 is formed at the tip of a rod 41 that is integrally formed with the buffer piston 40 and projects forward. The relief valve 38 communicates with the inlet channel 22 via a valve seat portion 43, and also communicates with the fluid storage tank 12 via an outlet channel 45 and a channel 46. A pressing spring 44 is interposed between the rear wall of the relief valve chamber 38 and the shoulder of the relief valve 42, and the pressing force of the pressing spring 44 causes the relief valve to
2 is constantly pressed toward the valve seat portion 43, and only when fluid having a pressure higher than a preset pressure is introduced through the inlet channel 22, the relief valve 42 opens against the pressure spring 44, and the relief valve 42 opens against the pressure spring 44. The fluid is configured to flow back to the fluid storage tank 12 via the outlet channel 45 and the channel 46 . At this time, since the buffer piston 40 has the through hole 39, it acts as a buffer against sudden movement of the relief valve 42. The rear piston rod 31 of the piston 29 passes through the rear wall of the cylinder block 21 via a seal member 47 so as to be able to freely slide into contact with the rear wall, and is provided on an operating rod 49 that physically extends further rearward from the rear end. The pair of engaging claws 50 and 51 engage with a protrusion 52 of a normally closed intermediate setting pressure responsive switch 5.
ピストン２９とシリンダブロック２１の後壁との間には
、後部ピストンロッド３１を取囲むようにして押圧ばね
４８が介装されており、この押圧ばね４８の押圧力によ
り、ピストン２９は常に前室Ａ側へ押圧されている。作
動杆４９の後方には上限設定圧応動スイッチ７が配設さ
れており、作動杆４９が一定距離だけ後退したときには
、この作動杆４９の後端面が上限設定圧応動スイッチ７
の突子５３を押圧して常閉型の上限設定圧応動スイッチ
７を開状態に置くと）もに、警報灯１１あるいはその他
任意の警報器を作動するようになつている。前部ピスト
ンロッド３０は比較的小径であり、また後部ピストンロ
ッド３１は比較的大径であるため、流路２５，２７を経
て前室Ａと後室Ｂとに同時に圧力流体が流入すると、ピ
ストン２９は前室Ａ側の流体圧に基つく押圧力と後室Ｂ
側の流体圧に基つく押圧力との間の押圧力差に起因して
後室Ｂ側への力を受ける。A pressure spring 48 is interposed between the piston 29 and the rear wall of the cylinder block 21 so as to surround the rear piston rod 31. Due to the pressure force of the pressure spring 48, the piston 29 is always kept on the front chamber A side. is being pushed to. An upper limit setting pressure responsive switch 7 is disposed behind the operating rod 49, and when the operating rod 49 moves back a certain distance, the rear end surface of the operating rod 49 becomes the upper limit setting pressure responsive switch 7.
Pressing the protrusion 53 to open the normally closed upper limit setting pressure responsive switch 7) activates the warning light 11 or any other alarm device. Since the front piston rod 30 has a relatively small diameter and the rear piston rod 31 has a relatively large diameter, when pressure fluid flows into the front chamber A and the rear chamber B simultaneously through the flow paths 25 and 27, the piston 29 is the pressing force based on the fluid pressure on the front chamber A side and the rear chamber B
A force is applied to the rear chamber B side due to a pressure difference between the pressure force based on the fluid pressure on the side and the pressure force on the rear chamber B side.
この力が押圧ばね４８の押圧力に打勝つとピストン２９
は後室Ｂ側へ移動し、その結果、係合爪５０，５１と係
合している突子５２が閉位置から開位置へ移動され、中
間設定応動スイッチ５が作動して流体圧発生装置４の作
動を停止するようになつている。このときのピストン２
９の移動量は入口流路２２から導入された流体の圧力に
比例する。押圧ばね４８のばね力は、入口流路２２から
導入された流体の圧力が第１の中間設定圧に達したとき
中間設定圧応動スイッチ５が開状態に切換わるように設
定されている。When this force overcomes the pressing force of the pressing spring 48, the piston 29
moves to the rear chamber B side, and as a result, the protrusion 52 engaged with the engaging claws 50 and 51 is moved from the closed position to the open position, and the intermediate setting response switch 5 is activated to close the fluid pressure generating device. The operation of 4 is now stopped. Piston 2 at this time
The amount of movement of 9 is proportional to the pressure of the fluid introduced from the inlet channel 22. The spring force of the pressure spring 48 is set so that the intermediate set pressure responsive switch 5 is switched to the open state when the pressure of the fluid introduced from the inlet channel 22 reaches the first intermediate set pressure.
また、押圧ばね４４のばね力は、中間設定圧応動スイッ
チ５が作動せず、入口流路２２から導入された流体の圧
力が第１の中間設定圧を超えて第２の中間設定圧に達し
たとき、逃し弁４２を開くように設定されている。さら
に、作動杆４９と突子５３との間の距離は、中間設定圧
応動スイッチ５も作動せず、逃し弁４２も充分に作動し
ないで、入口流路２２から導入された流体の圧力が第２
の中間設定圧を超えて上限設定圧に達したとき、作動杆
４９が突子５３を押圧して上限設定圧応動スイッチ７を
開状態に切換えるように設定されている。以上のように
構成されているので、流体圧発生装置４から流体作動系
９に送られる流体は、同時に入口流路２２にも流入し、
その圧力は常時シリンダ室２８の前室Ａ１後室Ｂ内に作
用すると）もに、逃し弁４２にも作用している。Further, the spring force of the pressing spring 44 is such that the intermediate setting pressure responsive switch 5 is not activated, and the pressure of the fluid introduced from the inlet channel 22 exceeds the first intermediate setting pressure and reaches the second intermediate setting pressure. When this occurs, the relief valve 42 is set to open. Further, the distance between the actuating rod 49 and the protrusion 53 is such that the pressure of the fluid introduced from the inlet flow path 22 does not reach the point where the intermediate set pressure response switch 5 does not operate and the relief valve 42 does not operate sufficiently. 2
When the intermediate setting pressure is exceeded and the upper limit setting pressure is reached, the operating rod 49 presses the protrusion 53 to switch the upper limit setting pressure response switch 7 to the open state. With the above configuration, the fluid sent from the fluid pressure generating device 4 to the fluid operating system 9 simultaneously flows into the inlet channel 22,
The pressure always acts on both the front chamber A1 and the rear chamber B of the cylinder chamber 28, as well as the relief valve 42.
入口流路２２から導入された流体の圧力が第１の中間設
定圧に満たない間は、主スツチ６が閉状態にある限り、
電気回路３は閉回路を形成し、流体作動系９は平常運転
を続ける。As long as the pressure of the fluid introduced from the inlet channel 22 is less than the first intermediate setting pressure, as long as the main switch 6 is in the closed state,
The electric circuit 3 forms a closed circuit, and the fluid operating system 9 continues normal operation.
入口回路２２から導入された流体の圧力が第１の中間設
定圧に達すると、ピストン２９の後退移動に伴つて中間
設定圧応動スイッチ５が閉状態から開状態に切換わるこ
とにより、電気回路３が遮断されて流体圧発生装置４の
作動が停止される。When the pressure of the fluid introduced from the inlet circuit 22 reaches the first intermediate set pressure, the intermediate set pressure response switch 5 is switched from the closed state to the open state as the piston 29 moves backward, and the electric circuit 3 is shut off, and the operation of the fluid pressure generating device 4 is stopped.
このとき、中間設定圧応動スイッチ５が故障していて電
気回路３が閉回路を維持していると、流体圧発生装置４
により発生された流体圧はさらに上昇し続ける。そして
、入口流路２２から導入された流体の圧力が第２の中間
設定圧に達すると、逃し弁４２が開き、入口流路２２か
ら導入された流体は逃し弁室３８、出口流路４５、流路
４６を経て流体貯槽１２へ還流され、流体作動系９へ送
られる物体の異常な上昇を未然に防ぐ。流体中に混入し
た固形成分やその他の不純物によつて出口流路４５や流
路４６が閉塞していたり、あるいは逃し弁４２の作動機
構の少なくとも一部が錆付いていたりして、入口流路２
２から導入された物体の圧力が第２の設定圧に達しても
逃し弁４２がその機能を充分に発揮しないときは、入口
流路２２から導入された流体の圧力はさらに上昇して上
限設定圧に達する。At this time, if the intermediate setting pressure responsive switch 5 is out of order and the electric circuit 3 maintains a closed circuit, the fluid pressure generating device 4
The fluid pressure generated by this continues to rise further. When the pressure of the fluid introduced from the inlet channel 22 reaches the second intermediate setting pressure, the relief valve 42 opens, and the fluid introduced from the inlet channel 22 passes through the relief valve chamber 38, the outlet channel 45, This prevents objects that are returned to the fluid storage tank 12 through the flow path 46 and sent to the fluid operating system 9 from rising abnormally. If the outlet flow path 45 or the flow path 46 is blocked by solid components or other impurities mixed into the fluid, or if at least a part of the operating mechanism of the relief valve 42 is rusted, the inlet flow path 2
When the relief valve 42 does not fully perform its function even if the pressure of the object introduced from the inlet channel 22 reaches the second set pressure, the pressure of the fluid introduced from the inlet channel 22 increases further and reaches the upper limit setting. pressure is reached.
このとき作動杆４９が突子５３を押圧することにより、
上限設定圧応動スイッチ７は閉状態から開状態に切換わ
つて電気回路３を遮断し、流体圧発生装置４の作動をｌ
停止すると）もに、警報灯１１のような警報器を作動さ
せる。したがつて、このときはたとえ電気回路３が遮断
されない場合でも、操作者は警報器により流体圧力の異
常な上昇を知ることができ、直ちに主スイッチ６を開放
して流体圧発生装置４・の作動を確実に停止させること
ができる。以上の実施例において、中間設定圧応動スイ
ッチ５は本発明の第１のスイッチを、また上限設定圧応
動スイッチ７は本発明の第２のスイッチをそれぞれ構成
している。そして同じく実施例におい）て前記第１の中
間設定圧は本発明の第１の設定圧に、前記第２の中間設
定圧は本発明の開弁設定圧に、また前記上限設定圧は本
発明の第２の設定圧にそれぞれ対応している。以上のよ
うに本発明によれば、流体圧により作動される流体作動
系９とそれに作動流体を供給するための流体圧発生装置
４との間を接続する流体回路８の途中に、その回路８内
の流体圧が所定値以上に上昇すると開弁して同回路８内
の流体を流体貯槽１２に還流させる逃し弁４２を設けた
、流体回路における安全弁装置において、前記流体回路
８内の流体圧の上昇に応じてシリンダブロック２１等の
ケーシング内を移動する一個のピストン２９と；前記流
体回路８内の流体圧が前記逃し弁４２の開弁設定圧より
も低い第１の設定圧まで上昇したとき前記ピストン２９
に連動して作動し、前記流体圧発生装置４の作動を停止
させる第１のスイッチ５と；同流体圧が前記逃し弁４２
の開弁設定圧よりも高い第２の設定圧まで上昇したとき
前記ピストン２９に連動して作動し、前記流体圧発生装
置４の作動を停止させる第２のスイッチ７と；を備えて
いるので、流体回路８内の流体圧が上昇して第１の設定
圧を越えると、先ず第１のスイッチ５が作動して流体圧
発生装置４の作動を自動的に停止させることができ、ま
たこの第１のスイッチ５が万一故障した場合でも、流体
圧の引き続く上昇により次に前記逃し弁４２が開弁して
流体回路８内の流体を流体貯槽１２に逃すことができ、
さらにこの逃し弁４２が万一故障した場合でも、流体圧
の引き続く上昇により次に前記第２の−スイッチ７を作
動させて流体圧発生装置４の作動を自動的に停止させる
ことができ、結局、流体回路８内の流体圧の大きさに応
じて三段階に亘りその流体圧上昇を停止させる機能を達
成することがてき、流体回路８内の過度の圧力上昇を確
実に防．止して同回路８内の流体機械や配管等を異常圧
力より有効に保護し得ると共に、流体圧発生装置４の過
負荷運転による故障発生を未然に防止し得る。At this time, the operating rod 49 presses the protrusion 53, so that
The upper limit setting pressure responsive switch 7 switches from the closed state to the open state, cuts off the electric circuit 3, and stops the operation of the fluid pressure generator 4.
When the vehicle stops), an alarm such as a warning light 11 is activated. Therefore, at this time, even if the electric circuit 3 is not cut off, the operator can detect an abnormal increase in fluid pressure through the alarm, and immediately open the main switch 6 to shut down the fluid pressure generator 4. Operation can be stopped reliably. In the embodiments described above, the intermediate set pressure responsive switch 5 constitutes the first switch of the present invention, and the upper limit set pressure responsive switch 7 constitutes the second switch of the present invention. In the same example), the first intermediate set pressure is the first set pressure of the present invention, the second intermediate set pressure is the valve opening set pressure of the present invention, and the upper limit set pressure is the same as the valve opening set pressure of the present invention. , respectively, correspond to the second set pressure. As described above, according to the present invention, the circuit 8 is installed in the middle of the fluid circuit 8 that connects the fluid working system 9 operated by fluid pressure and the fluid pressure generating device 4 for supplying working fluid thereto. In a safety valve device for a fluid circuit, which is provided with a relief valve 42 that opens when the fluid pressure in the circuit 8 rises to a predetermined value or more and causes the fluid in the circuit 8 to flow back to the fluid storage tank 12, the fluid pressure in the fluid circuit 8 is increased. one piston 29 moves within the casing of the cylinder block 21 etc. in accordance with the rise in the pressure; the fluid pressure within the fluid circuit 8 has increased to a first set pressure that is lower than the valve opening set pressure of the relief valve 42; When the piston 29
a first switch 5 that operates in conjunction with the fluid pressure generating device 4 to stop the operation of the fluid pressure generating device 4;
and a second switch 7 that operates in conjunction with the piston 29 to stop the operation of the fluid pressure generating device 4 when the pressure rises to a second set pressure higher than the valve opening set pressure of the fluid pressure generating device 4. , when the fluid pressure in the fluid circuit 8 rises and exceeds the first set pressure, the first switch 5 is activated to automatically stop the operation of the fluid pressure generating device 4; Even if the first switch 5 were to fail, the relief valve 42 would then open due to the continued rise in fluid pressure, allowing the fluid in the fluid circuit 8 to escape to the fluid reservoir 12;
Furthermore, even if this relief valve 42 should fail, the second - switch 7 can be activated next due to the continued increase in fluid pressure, and the operation of the fluid pressure generating device 4 can be automatically stopped, eventually. , it is possible to achieve a function of stopping the increase in fluid pressure in three stages depending on the magnitude of the fluid pressure in the fluid circuit 8, and to reliably prevent an excessive pressure increase in the fluid circuit 8. This effectively protects the fluid machinery, piping, etc. in the circuit 8 from abnormal pressure, and also prevents failures due to overload operation of the fluid pressure generating device 4.
特に本発明では、流体回路８内の流体圧が逃し弁４２の
開弁設定圧に達する前に先ず第１のスイッチ５が作動し
て流体圧発生装置４の作動を停止させるようにしている
ので、この第１のスイッチ５が故障しない限り逃し弁４
２が開弁される機会はなく、即ち、全体として逃し弁４
２が開弁される機会が極めて少なくなるから、前記従来
装置のように逃し弁４２の度重なる開閉により流体中の
固形成分等が同弁４２の弁座部と弁体間に挾み込まれた
り弁座部を摩耗させたりしてその閉弁を妨げるといつた
不都合を来たすおそれがなくなり、逃し弁４２からの流
体のリークを効果的に防止し得る。しかも２個の独立し
たスイッチ５，７を共通のピストン２９により作動させ
るようにしているので、部品点数が少なく構造が簡単で
コストを低減し得るものである。In particular, in the present invention, the first switch 5 is activated to stop the operation of the fluid pressure generating device 4 before the fluid pressure in the fluid circuit 8 reaches the opening set pressure of the relief valve 42. , unless this first switch 5 fails, the relief valve 4
There is no chance that the relief valve 2 is opened, that is, the relief valve 4 as a whole
2 is opened, the chances of opening the relief valve 42 are extremely small, so solid components in the fluid are trapped between the valve seat and the valve body of the relief valve 42 due to repeated opening and closing of the relief valve 42 as in the conventional device. This eliminates the risk of causing inconveniences such as abrasion of the valve seat and preventing the valve from closing, and leakage of fluid from the relief valve 42 can be effectively prevented. Furthermore, since the two independent switches 5 and 7 are operated by a common piston 29, the number of parts is small, the structure is simple, and costs can be reduced.
第１図は本発明の一実施例に基づく安全弁装置の全体的
配線概念図、第２図は第１図の安全弁装置の要部拡大一
部断面詳細説明図である。
４・・・・・・流体圧発生装置、５・・・・・・第１の
スイッチとしての中間設定圧応動スイッチ、７・・・・
・・第２のスイッチとしての上限設定圧応動スイッチ、
８・・・・・・流体回路、９・・・・・・流体作動系、
２１・・・・・・ケーシングとしてのシリンダブロック
、２２・・・・・・入口流路、２９・・・・・ゼストン
、４２・・・・・・逃し弁。FIG. 1 is an overall wiring conceptual diagram of a safety valve device according to an embodiment of the present invention, and FIG. 2 is an enlarged partial cross-sectional detailed explanatory diagram of essential parts of the safety valve device of FIG. 4...Fluid pressure generating device, 5...Intermediate setting pressure response switch as a first switch, 7...
... Upper limit setting pressure responsive switch as a second switch,
8...Fluid circuit, 9...Fluid operation system,
21...Cylinder block as a casing, 22...Inlet flow path, 29...Zeston, 42...Relief valve.
Claims (1)
流体を供給するための流体圧発生装置４との間を接続す
る流体回路８の途中に、その回路８内の流体圧が所定値
以上に上昇すると開弁して同回路８内の流体を流体貯槽
１２に還流させる逃し弁４２を設けた、流体回路におけ
る安全弁装置において、前記流体回路８内の流体圧の上
昇に応じてシリンダブロック２１等のケーシング内を移
動する一個のピストン２９と；前記流体回路８内の流体
圧が前記逃し弁４２の開弁設定圧よりも低い第１の設定
圧まで上昇したとき前記ピストン２９に連動して作動し
、前記流体圧発生装置４の作動を停止させる第１のスイ
ッチ５と；同流体圧が前記逃し弁４２の開弁設定圧より
も高い第２の設定圧まで上昇したとき前記ピストン２９
に連動して作動し、前記流体圧発生装置４の作動を停止
させる第２のスイッチ７と；を備えてなる、流体回路に
おける安全弁装置。1 In the middle of the fluid circuit 8 that connects the fluid working system 9 operated by fluid pressure and the fluid pressure generating device 4 for supplying working fluid thereto, if the fluid pressure in the circuit 8 exceeds a predetermined value. In a safety valve device for a fluid circuit, which is provided with a relief valve 42 that opens when the valve rises and allows the fluid in the circuit 8 to flow back to the fluid storage tank 12, the cylinder block 21, etc. a piston 29 that moves within the casing of the fluid circuit 8; operates in conjunction with the piston 29 when the fluid pressure within the fluid circuit 8 rises to a first set pressure lower than the opening set pressure of the relief valve 42; and a first switch 5 that stops the operation of the fluid pressure generating device 4; when the fluid pressure rises to a second set pressure higher than the opening set pressure of the relief valve 42, the piston 29;
A safety valve device in a fluid circuit, comprising: a second switch 7 that is operated in conjunction with and stops the operation of the fluid pressure generating device 4;
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5847277A JPS6059474B2 (en) | 1977-05-20 | 1977-05-20 | Safety valve device in fluid circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5847277A JPS6059474B2 (en) | 1977-05-20 | 1977-05-20 | Safety valve device in fluid circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS53144027A JPS53144027A (en) | 1978-12-15 |
| JPS6059474B2 true JPS6059474B2 (en) | 1985-12-25 |
Family
ID=13085362
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP5847277A Expired JPS6059474B2 (en) | 1977-05-20 | 1977-05-20 | Safety valve device in fluid circuit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6059474B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1992009838A1 (en) * | 1990-11-30 | 1992-06-11 | Kabushiki Kaisha Komatsu Seisakusho | Switch for detecting the operation of control valve spool |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6112113U (en) * | 1984-06-22 | 1986-01-24 | 亦仁 黄 | Safety valve automatic pressure reducing device |
-
1977
- 1977-05-20 JP JP5847277A patent/JPS6059474B2/en not_active Expired
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1992009838A1 (en) * | 1990-11-30 | 1992-06-11 | Kabushiki Kaisha Komatsu Seisakusho | Switch for detecting the operation of control valve spool |
| US5484352A (en) * | 1990-11-30 | 1996-01-16 | Kabushiki Kaisha Komatsu Seisakusho | Switch for detecting operation of control valve spool |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS53144027A (en) | 1978-12-15 |
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