【０００１】
【発明の属する技術分野】
本発明は蒸気や圧縮空気配管系に取り付けて、出口側圧力を入口側圧力よりも低い所望の設定圧力に維持する減圧弁に関する。
【０００２】
【従来の技術】
従来の減圧弁は例えば実開昭５８−２８３１２号公報に示されている。ここに示されたものは、弁ケーシングに入口と出口を形成し、入口と出口を連通する弁口を開けた弁座を弁ケーシングに取り付け、弁口を開閉する弁体を弁口の下方にばねで閉弁方向に付勢して配置し、出口側圧力と圧力設定部材の設定力との偏差に基づいて変位する圧力応動部材により操作棒を介して弁体を駆動して弁口を開閉するものにおいて、操作棒の上部を案内部材で上下に摺動自在に案内したものである。
【０００３】
【発明が解決しようとする課題】
上記従来の減圧弁は、操作棒の上部が案内部材で上下に摺動自動に案内されるだけであるので、操作棒が傾き易い。そのため、操作棒と案内部材との摺動抵抗が大きく、圧力の変動に対する応答性が悪いという問題点があった。
【０００４】
従って本発明の技術的課題は、操作棒の傾きを防止して、圧力の変動に対する応答性の良い減圧弁を提供することである。
【０００５】
【課題を解決するための手段】
上記の技術的課題を解決するために講じた本発明の技術的手段は、弁ケーシングに入口と出口を形成し、入口と出口を連通する弁口を開けた弁座を弁ケーシングに取り付け、弁口を開閉する弁体を弁口の下方にばねで閉弁方向に付勢して配置し、出口側圧力と圧力設定部材の設定力との偏差に基づいて変位する圧力応動部材により操作棒を介して弁体を駆動して弁口を開閉する減圧弁であって、操作棒の上部を案内部材で上下に摺動自在に案内したものにおいて、弁体の上面にほぼ円錐状の凹面を形成し、操作棒の下端面にほぼ半球状の凸面を形成し、弁体の円錐状凹面に操作棒の半球状凸面を当接させたことを特徴とする減圧弁にある。
【０００６】
【発明の実施の形態】
本発明は、操作棒の上部を案内部材で上下に摺動自在に案内し、弁体の上面にほぼ円錐状の凹面を形成し、操作棒の下端面にほぼ半球状の凸面を形成し、弁体の円錐状凹面に操作棒の半球状凸面を当接させたものである。そのため、操作棒は上部と下端がそれぞれ案内部材と弁体で案内されるので傾き難くなる。そのため、操作棒と案内部材との摺動抵抗が小さく、圧力の変動に対する応答性が良くなる。
【０００７】
【実施例】
上記の技術的手段の具体例を示す実施例を説明する（図１参照）。
図１は本発明による減圧弁の実施例の断面図である。減圧弁の弁ケーシングは、本体１と本体１に締結した蓋２とから成る。本体１の上部と蓋２の間に圧力設定部材としてのコイル状の圧力設定ばね３と圧力応動部材としてのベローズ４を配置する。
【０００８】
本体１に入口５と出口６を形成し、入口５と出口６の間に弁座７を固定し、弁座７に形成した弁口８を通して入口５と出口６を連通する。弁口８の下方に弁口８を開閉する弁体９を配置する。弁体９の上面にほぼ円錐状の凹面１０を形成する。弁体９の上方に操作棒１１を配置する。操作棒１１の下端面にほぼ半球状の凸面１２を形成する。弁体９の円錐状の凹面１０に操作棒１１の半球状の凸面１２を当接させる。操作棒１１の上端は下部ばね受け１３の収容孔１４に収容する。操作棒１１の上部はスナップリング１５で本体１に固定した案内部材１６の案内孔１７で上下に摺動自在に案内する。案内部材１６に出口６側圧力を導入する連通孔１８を形成する。
【０００９】
弁体９と本体１の底壁の間に弁体９を閉弁方向に付勢するコイル状の弁体ばね１９を配置する。弁体９と弁体ばね１９を囲って円筒状のスクリーン２０を配置する。スクリーン２０は、弁座７の下端面に形成した外方に向かって上方に拡がるテーパー面２１と、本体１の底壁に形成した段部２２の間に挟んで固定する。
【００１０】
蓋２の天井壁に調節ねじ２３を取り付け、ロックナット２４で回り止めをする。調節ねじ２３の下部に抜け出し防止用のスナップリング２５を取り付ける。調節ねじ２３の内端は球体２６と上部ばね受け２７を介して圧力設定ばね３の上端に接する。圧力設定ばね３の下端は下部ばね受け１３の上端に接する。ベローズ４の上端は蓋２と本体１の間に固定したリング状の取付部材２８に固定し、下端は下部ばね受け１３の外周に固定して閉塞する。
【００１１】
次に上記実施例の作用を説明する。出口６側の圧力が設定圧力よりも低下すると、ベローズ４は圧力設定ばね３のばね力により収縮し、弁体ばね１９のばね力に抗して操作棒１１を介して弁体９を下方に変位させて弁口８を開口する。弁口８の開口により入口５側の高圧の流体が出口６側に供給され、出口６側の圧力が回復する。出口６側の圧力が所望値まで回復すると、ベローズ４は伸張して元の位置に戻り、弁体９は弁体ばね１９のばね力により弁口８を閉口する。
【００１２】
【発明の効果】
上記のように本発明は、操作棒の上部と下端をそれぞれ案内部材と弁体で案内して操作棒を傾き難くしたことにより、操作棒と案内部材との摺動抵抗を小さくでき、圧力の変動に対する応答性が良くなるという優れた効果を生じる。
【図面の簡単な説明】
【図１】本発明による減圧弁の実施例の断面図である。
【符号の説明】
１ 本体
２ 蓋
３ 圧力設定ばね
４ ベローズ
５ 入口
６ 出口
７ 弁座
８ 弁口
９ 弁体
１０ 凹面
１１ 操作棒
１２ 凸面
１６ 案内部材
１７ 案内孔
１９ 弁体ばね[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a pressure reducing valve which is attached to a steam or compressed air piping system to maintain an outlet pressure at a desired set pressure lower than an inlet pressure.
[0002]
[Prior art]
A conventional pressure reducing valve is disclosed, for example, in Japanese Utility Model Laid-Open No. 58-28312. The one shown here forms an inlet and an outlet in the valve casing, attaches a valve seat with a valve opening communicating the inlet and the outlet to the valve casing, and places a valve body that opens and closes the valve below the valve opening. The valve opening is opened and closed by driving the valve body via the operating rod by a pressure responsive member that is urged in the valve closing direction by a spring and displaced based on the deviation between the outlet side pressure and the set force of the pressure setting member. In this configuration, the upper portion of the operation rod is guided by a guide member so as to be slidable up and down.
[0003]
[Problems to be solved by the invention]
In the above-described conventional pressure reducing valve, since the upper part of the operation rod is only guided automatically up and down by the guide member, the operation rod is easily inclined. Therefore, there has been a problem that the sliding resistance between the operation rod and the guide member is large, and the response to pressure fluctuation is poor.
[0004]
Therefore, a technical problem of the present invention is to provide a pressure reducing valve having a high responsiveness to pressure fluctuation by preventing the operation rod from being tilted.
[0005]
[Means for Solving the Problems]
The technical means of the present invention taken in order to solve the above technical problem is to form an inlet and an outlet in a valve casing, attach a valve seat having an open valve port communicating the inlet and the outlet to the valve casing, A valve element for opening and closing the port is disposed below the valve port by urging in a valve closing direction by a spring, and the operating rod is displaced based on a deviation between an outlet side pressure and a set force of the pressure setting member. A pressure-reducing valve that opens and closes a valve port by driving a valve element through a guide member, in which an upper portion of an operating rod is slidably guided up and down by a guide member, and a substantially conical concave surface is formed on an upper surface of the valve element. The pressure reducing valve is characterized in that a substantially hemispherical convex surface is formed on the lower end surface of the operating rod, and the hemispherical convex surface of the operating rod is brought into contact with the conical concave surface of the valve element.
[0006]
BEST MODE FOR CARRYING OUT THE INVENTION
The present invention guides the upper portion of the operation rod slidably up and down by a guide member, forms a substantially conical concave surface on the upper surface of the valve body, and forms a substantially hemispherical convex surface on the lower end surface of the operation rod, The hemispherical convex surface of the operating rod is brought into contact with the conical concave surface of the valve body. Therefore, the operation rod is hardly inclined because the upper and lower ends are guided by the guide member and the valve body, respectively. Therefore, the sliding resistance between the operation rod and the guide member is small, and the responsiveness to pressure fluctuation is improved.
[0007]
【Example】
An embodiment showing a specific example of the above technical means will be described (see FIG. 1).
FIG. 1 is a sectional view of an embodiment of a pressure reducing valve according to the present invention. The valve casing of the pressure reducing valve includes a main body 1 and a lid 2 fastened to the main body 1. A coil-shaped pressure setting spring 3 as a pressure setting member and a bellows 4 as a pressure responsive member are arranged between the upper part of the main body 1 and the lid 2.
[0008]
An inlet 5 and an outlet 6 are formed in the main body 1, a valve seat 7 is fixed between the inlet 5 and the outlet 6, and the inlet 5 and the outlet 6 are communicated through a valve port 8 formed in the valve seat 7. A valve body 9 that opens and closes the valve port 8 is disposed below the valve port 8. A substantially conical concave surface 10 is formed on the upper surface of the valve body 9. The operation rod 11 is arranged above the valve body 9. A substantially hemispherical convex surface 12 is formed on the lower end surface of the operation rod 11. The hemispherical convex surface 12 of the operating rod 11 is brought into contact with the conical concave surface 10 of the valve body 9. The upper end of the operating rod 11 is housed in the housing hole 14 of the lower spring receiver 13. The upper part of the operation rod 11 is guided slidably up and down by a guide hole 17 of a guide member 16 fixed to the main body 1 by a snap ring 15. A communication hole is formed in the guide member for introducing a pressure on the outlet side.
[0009]
A coil-shaped valve body spring 19 for urging the valve body 9 in the valve closing direction is disposed between the valve body 9 and the bottom wall of the main body 1. A cylindrical screen 20 is arranged around the valve body 9 and the valve body spring 19. The screen 20 is fixed by being sandwiched between a tapered surface 21 formed on the lower end surface of the valve seat 7 and extending upward and outward and a step 22 formed on the bottom wall of the main body 1.
[0010]
An adjusting screw 23 is attached to the ceiling wall of the lid 2, and is stopped by a lock nut 24. A snap ring 25 is attached to the lower part of the adjusting screw 23 to prevent the screw from coming off. The inner end of the adjusting screw 23 contacts the upper end of the pressure setting spring 3 via the spherical body 26 and the upper spring receiver 27. The lower end of the pressure setting spring 3 contacts the upper end of the lower spring receiver 13. The upper end of the bellows 4 is fixed to a ring-shaped mounting member 28 fixed between the lid 2 and the main body 1, and the lower end is fixedly closed on the outer periphery of the lower spring receiver 13.
[0011]
Next, the operation of the above embodiment will be described. When the pressure on the outlet 6 side becomes lower than the set pressure, the bellows 4 contracts due to the spring force of the pressure setting spring 3, and moves the valve body 9 downward via the operating rod 11 against the spring force of the valve body spring 19. The valve port 8 is opened by being displaced. The high-pressure fluid on the inlet 5 side is supplied to the outlet 6 side by the opening of the valve port 8, and the pressure on the outlet 6 side recovers. When the pressure on the outlet 6 side recovers to a desired value, the bellows 4 expands and returns to the original position, and the valve element 9 closes the valve port 8 by the spring force of the valve element spring 19.
[0012]
【The invention's effect】
As described above, the present invention can reduce the sliding resistance between the operation rod and the guide member by guiding the upper and lower ends of the operation rod with the guide member and the valve body, respectively, so that the operation rod is hardly inclined. An excellent effect that the response to the fluctuation is improved is produced.
[Brief description of the drawings]
FIG. 1 is a sectional view of an embodiment of a pressure reducing valve according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Main body 2 Lid 3 Pressure setting spring 4 Bellows 5 Inlet 6 Outlet 7 Valve seat 8 Valve port 9 Valve body 10 Concave surface 11 Operating rod 12 Convex surface 16 Guide member 17 Guide hole 19 Valve body spring