JP4463631B2

JP4463631B2 - Valve seat structure

Info

Publication number: JP4463631B2
Application number: JP2004196355A
Authority: JP
Inventors: 啓一柳瀬; 誠司藤本
Original assignee: Kubota Corp
Current assignee: Kubota Corp
Priority date: 2004-07-02
Filing date: 2004-07-02
Publication date: 2010-05-19
Anticipated expiration: 2024-07-02
Also published as: JP2006017237A

Description

本発明はバルブの弁座構造に関し、内面シール構造の回転弁、あるいは外面シール構造のボール弁やバタフライ弁などのバルブの弁座に好適なバルブの弁座構造に関する。 The present invention relates to a valve seat structure of a valve, and relates to a valve seat structure suitable for a valve seat of a rotary valve having an inner seal structure or a ball valve or a butterfly valve having an outer seal structure.

従来より、バルブの弁座構造として、図６に示す偏心内面シール弁に適用されたものがある。このバルブの弁座構造は、弁箱１に挿入した弁箱スリーブ２の出口２ａ近傍に径外に張り出して設けた弁箱側シート部３と、弁体４の裏面に形成した凹球面状の弁体側シート部５とを備え、弁箱側シート部３は、弁箱スリーブ２の出口２ａ近傍に径外に張り出して形成した鍔部６に嵌着された硬質ゴムからなる弾性シール材７によって構成されており、弁体４は、弁箱スリーブ２の出口２ａに対して偏心した位置を中心として回動自在に弁箱スリーブ２に取付けられている。したがって、実線で示す弁体４の閉弁状態は、弾性シール材７に凹球面状の弁体側シート部５を密着させて、弁箱スリーブ２の出口２ａを弁体４で閉塞することによって得られ、この閉弁状態で弁箱１の流入口として機能する弁箱スリーブ２の入口２ｂから落下導入されたたとえば粉体が弁体４の内面、つまり凹球面状の弁体側シート部５の上面に堆積される。そして、この閉弁状態から図６の二点鎖線で示すように、弁体４を９０度回転させて、弁箱スリーブ２の出口２ａを開放すると、弁体４の内面に堆積されていた前記粉体が前記出口２ａから落下することになる（特許文献１）。 Conventionally, there has been a valve seat structure applied to the eccentric inner surface seal valve shown in FIG. The valve seat structure of this valve has a concave spherical shape formed on the back surface of the valve body 4 and the valve box side seat portion 3 that projects out of the diameter near the outlet 2a of the valve sleeve 2 inserted into the valve box 1. The valve body side seat portion 5 is provided with an elastic sealing material 7 made of hard rubber and fitted on a flange portion 6 that is formed by projecting outward in the vicinity of the outlet 2a of the valve sleeve 2. The valve body 4 is attached to the valve box sleeve 2 so as to be rotatable about a position eccentric with respect to the outlet 2a of the valve box sleeve 2. Therefore, the closed state of the valve body 4 shown by the solid line is obtained by bringing the concave spherical valve body side seat portion 5 into close contact with the elastic sealing material 7 and closing the outlet 2 a of the valve box sleeve 2 with the valve body 4. In this closed state, for example, the powder dropped from the inlet 2b of the valve box sleeve 2 that functions as the inlet of the valve box 1 is the inner surface of the valve body 4, that is, the upper surface of the concave spherical valve body side seat portion 5. It is deposited on. Then, as shown by a two-dot chain line in FIG. 6, when the valve body 4 is rotated 90 degrees and the outlet 2 a of the valve box sleeve 2 is opened, the valve body 4 is deposited on the inner surface of the valve body 4. The powder falls from the outlet 2a (Patent Document 1).

一方、他のバルブの弁座構造として、図７に示すバタフライ弁に適用されたものがある。このバルブの弁座構造は、弁箱８に基部９ａが取付けられた断面略Ｌ字状の金属板製の弁座本体９を有し、この弁座本体９の先端側折曲片を弁箱側シート部９ｂとして機能させ、図示されているような弁体１０の閉弁時には、弁箱側シート部９ｂの弾性により該弁箱側シート部９ｂを弁体１０周縁部の弁体側シート部１０ａに圧接させるとともに、弁箱８と金属板製の弁座本体９の基部側垂直片の間に介設した皿バネからなる押圧力調整板１１の押圧力付勢によって、弁箱側シート部９ｂをより強力に弁体側シート部１０ａに圧接させてシール性を保持するように構成されている（特許文献２）。 On the other hand, as a valve seat structure of another valve, there is one applied to the butterfly valve shown in FIG. The valve seat structure of this valve has a valve seat body 9 made of a metal plate having a substantially L-shaped cross section with a base portion 9a attached to the valve box 8, and the bent side of the valve seat body 9 is connected to the valve box. When the valve body 10 is closed as shown in the figure, it functions as the side seat portion 9b, and the valve box side seat portion 9b is caused by the elasticity of the valve box side seat portion 9b so that the valve body side seat portion 10a at the periphery of the valve body 10 is shown. And the valve box side seat portion 9b by the pressing force urging of the pressing force adjustment plate 11 made of a disc spring interposed between the valve box 8 and the base side vertical piece of the valve seat body 9 made of metal plate. Is more strongly pressed against the valve body side seat portion 10a to maintain the sealing performance (Patent Document 2).

実公昭５２−１１７６３１号公報Japanese Utility Model Publication No. 52-117631 実開平５−８１４０号公報Japanese Utility Model Publication No. 5-8140

前記特許文献１に記載のバルブの弁座構造は、弁体４が実線で示す閉弁状態にあるときには、弁体４の裏面に形成した凹球面状の弁体側シート部５が弾性シール材７からなる弁箱側シート部３に密着することによって、シール性を保持するように構成されているので、弁箱１内に弁体４を押し上げ方向に付勢する流体圧（たとえばガス圧）Ｐが作用する配管系に、偏心内面シール弁を適用している場合は、前記ガス圧Ｐによって凹球面状の弁体側シート部５が弾性シール材７からなる弁箱側シート部３方向に付勢されて、凹球面状の弁体側シート部５と弾性シール材７からなる弁箱側シート部３との密着力を高め、閉弁時のシール性を向上させることができる。 In the valve seat structure of the valve described in Patent Document 1, when the valve body 4 is in a closed state indicated by a solid line, the concave spherical valve body side seat portion 5 formed on the back surface of the valve body 4 is an elastic sealing material 7. Since it is configured to maintain the sealing performance by being in close contact with the valve box side seat portion 3, the fluid pressure (for example, gas pressure) P that urges the valve body 4 in the valve box 1 in the upward direction. In the case where an eccentric inner surface seal valve is applied to the piping system on which the valve acts, the concave spherical spherical valve body side seat portion 5 is urged by the gas pressure P toward the valve box side seat portion 3 made of the elastic seal material 7. Thus, the adhesion between the concave spherical valve body side seat portion 5 and the valve case side seat portion 3 made of the elastic seal material 7 can be increased, and the sealing performance when the valve is closed can be improved.

ところが、前記ガス圧Ｐが作用しない配管系に偏心内面シール弁が適用されると、閉弁時のシール性は、弁体４が実線で示す閉弁位置に回動してきたときに決定される弁体側シート部５と弁箱側シート部３との密着力のみに委ねられることになるので、弁体４の閉弁状態において、弁体４の自重および該弁体４を取付けている回動軸４Ａと軸受（図示省略）との間に生じる軸受隙間の影響で、弁体４が軸受隙間分に相当して下降すると、弁体側シート部５と弁箱側シート部３との密着力が低下して、閉弁時のシール性を低下させるとともに、弁体側シート部５と弁箱側シート部３との間に粉体が噛み込まれて、弁箱側シート部３を摩耗損傷させ、シール性をより一層低下させる問題がある。 However, when an eccentric inner surface seal valve is applied to a piping system to which the gas pressure P does not act, the sealing performance when the valve is closed is determined when the valve body 4 has turned to the valve closing position indicated by the solid line. Since only the contact force between the valve body side seat portion 5 and the valve box side seat portion 3 is entrusted, when the valve body 4 is in the closed state, the weight of the valve body 4 and the rotation of attaching the valve body 4 are attached. When the valve body 4 descends corresponding to the bearing clearance due to the influence of the bearing clearance generated between the shaft 4A and the bearing (not shown), the adhesion between the valve body side seat portion 5 and the valve case side seat portion 3 is increased. And lowering the sealing performance at the time of closing the valve, and the powder is caught between the valve body side seat portion 5 and the valve case side seat portion 3 to wear and damage the valve case side seat portion 3, There is a problem of further reducing the sealing performance.

一方、前記特許文献２に記載のバルブの弁座構造は、弁体１０の閉弁時には、弁箱側シート部９ｂの弾性により該弁箱側シート部９ｂを弁体１０周縁部の弁体側シート部１０ａに圧接させるとともに、皿バネからなる押圧力調整板１１の押圧力付勢によって、弁箱側シート部９ｂをより強力に弁体側シート部１０ａに圧接させてシール性を保持することができる。このため、弁体１０に流体圧Ｐ１が作用して、弁体１０が該弁体４を取付けている回転軸（図示省略）と軸受との間に生じる軸受隙間の影響で流体圧Ｐ１の方向に移動しても、図示している弁体１０の半円部分では、弁箱側シート部９ｂの弾性によって弁体１０の移動を吸収して、弁箱側シート部９ｂを弁体１０周縁部の弁体側シート部１０ａに圧接させることでシール性を確保することができる。しかし、図示されていない弁体１０の半円部分では、弁体１０自体の歪みや前記軸受隙間の影響で、弁体側シート部１０ａが弁箱側シート部９ｂに過剰に押し付けられることになって、弁箱側シート部９ｂを塑性変形させ、弁箱側シート部９ｂと弁体側シート部１０ａとの圧接力を低下させて、閉弁時のシール性を低下させるといった相反する状態が生じる。 On the other hand, in the valve seat structure of the valve disclosed in Patent Document 2, when the valve body 10 is closed, the valve box side seat portion 9b is made elastic by the valve box side seat portion 9b so that the valve body side seat at the periphery of the valve body 10 is used. In addition to being brought into pressure contact with the portion 10a, the valve box side seat portion 9b can be more strongly brought into pressure contact with the valve body side seat portion 10a by the pressing force urging of the pressing force adjusting plate 11 made of a disc spring to maintain the sealing performance. . For this reason, the fluid pressure P1 acts on the valve body 10, and the direction of the fluid pressure P1 due to the influence of the bearing gap generated between the rotary shaft (not shown) on which the valve body 10 is mounted with the valve body 4 and the bearing. Even when the valve body 10 is moved, the semicircular portion of the illustrated valve body 10 absorbs the movement of the valve body 10 by the elasticity of the valve box side seat portion 9b, and the valve box side seat portion 9b is moved to the peripheral portion of the valve body 10. The sealing performance can be ensured by pressing the valve body side seat portion 10a. However, in the semicircular portion of the valve body 10 (not shown), the valve body side seat portion 10a is excessively pressed against the valve box side seat portion 9b due to the distortion of the valve body 10 itself and the influence of the bearing gap. Then, the valve box side seat portion 9b is plastically deformed, the pressure contact force between the valve box side seat portion 9b and the valve body side seat portion 10a is lowered, and the contradictory state occurs such that the sealing performance at the time of closing the valve is lowered.

また、弁体１０の閉弁時において、弁体１０に流体圧Ｐが作用すると、図示している弁体１０の半円部分では、弁体１０自体の歪みや前記軸受隙間の影響で、弁体１０が流体圧Ｐの方向に移動して、弁体側シート部１０ａを弁箱側シート部９ｂに過剰に押し付けることになって、弁箱側シート部９ｂを塑性変形させ、弁箱側シート部９ｂと弁体側シート部１０ａとの圧接力を低下させて、閉弁時のシール性を低下させることになり、図示されていない弁体１０の半円部分では、弁体１０が軸受隙間の影響で流体圧Ｐの方向に移動しても、弁箱側シート部９ｂの弾性によって弁体１０の移動を吸収して、弁箱側シート部９ｂを弁体１０周縁部の弁体側シート部１０ａに圧接させることによって、シール性を確保するといった相反する状態が生じる。 In addition, when the fluid pressure P acts on the valve body 10 when the valve body 10 is closed, the valve body 10 shown in the figure has a semicircular portion due to the distortion of the valve body 10 itself and the influence of the bearing gap. The body 10 moves in the direction of the fluid pressure P, and the valve body side seat portion 10a is excessively pressed against the valve box side seat portion 9b, so that the valve box side seat portion 9b is plastically deformed, and the valve box side seat portion The pressure contact force between the valve body side seat portion 10a and the valve body side seat portion 10a is reduced to reduce the sealing performance when the valve is closed. In the semicircular portion of the valve body 10 (not shown), the valve body 10 is affected by the bearing clearance. Even if it moves in the direction of fluid pressure P, the movement of the valve body 10 is absorbed by the elasticity of the valve box side seat portion 9b, and the valve box side seat portion 9b is moved to the valve body side seat portion 10a at the periphery of the valve body 10. By pressing, there is a conflicting situation such as ensuring sealing performance. .

さらに、弁箱側シート部９ｂの塑性変形によって閉弁時のシール性が低下すると、弁体１０の閉弁時に、流体圧ＰまたはＰ１が弁体１０に作用して、前記軸受隙間の影響で弁体１０が流体圧ＰまたはＰ１の方向に移動しても、塑性変形している弁箱側シート部９ｂでは、弁体１０の流体圧ＰまたはＰ１方向の移動を吸収して、弁箱側シート部９ｂを弁体１０周縁部の弁体側シート部１０ａに圧接させることが期待できず、閉弁時のシール性を低下させることになるなどの問題がある。 Furthermore, if the sealing performance at the time of closing the valve is lowered due to plastic deformation of the valve box side seat portion 9b, the fluid pressure P or P1 acts on the valve body 10 when the valve body 10 is closed, and is affected by the bearing gap. Even if the valve body 10 moves in the direction of the fluid pressure P or P1, the valve box side seat portion 9b that is plastically deformed absorbs the movement of the valve body 10 in the direction of the fluid pressure P or P1 to the valve box side. There is a problem in that the seat portion 9b cannot be expected to be brought into pressure contact with the valve body side seat portion 10a at the peripheral portion of the valve body 10 and the sealing performance at the time of closing the valve is lowered.

本発明は、このような問題を解決するものであって、その目的とするところは、塑性変形が抑制される弁座の弾性による付勢力で高いシール性を確保することができるとともに、弁体閉弁時の封止流体圧で弁座を付勢して高いシール性を確保することができ、内面シール構造の回転弁、あるいは外面シール構造のボール弁などのバルブに好適なバルブの弁座構造を提供することにある。 The present invention solves such a problem, and an object of the present invention is to ensure a high sealing performance by an urging force due to the elasticity of a valve seat in which plastic deformation is suppressed. The valve seat can be urged by the sealing fluid pressure when the valve is closed to ensure high sealing performance, and it is suitable for a valve such as a rotary valve with an internal seal structure or a ball valve with an external seal structure. To provide a structure.

前記目的を達成するために、請求項１記載の発明に係るバルブの弁座構造は、基部が弁箱側に取付けられたベロー型弁座の先端部に弁体に設けた弁体シート部に接離する弁箱側シート部が設けられ、該ベロー型弁座の弾性により付勢されて前記弁体の閉弁時に前記弁箱側シート部が前記弁体シート部に密着するように構成されているとともに、前記弁体閉弁時の封止流体圧が前記ベロー型弁座を付勢して前記弁箱側シート部を前記弁体シート部に密着させるように構成されており、前記弁体閉弁時外圧として前記ベロー型弁座に負荷される圧力が該ベロー型弁座を軸方向にのばす作用を増大させるために、前記ベロー型弁座の軸線から前記基部の外端までの取付半径Ｒと、前記軸線から前記弁体の閉弁状態で前記弁体シート部に密着している前記弁箱側シート部までのシール半径Ｒ１との間に、Ｒ＜Ｒ１の関係を有していることを特徴とするものである。 In order to achieve the object, the valve seat structure according to the first aspect of the present invention includes a valve body seat portion provided on a valve body at a distal end portion of a bellows type valve seat having a base portion attached to the valve box side. A valve box side seat portion is provided that contacts and separates, and is configured to be urged by the elasticity of the bellows type valve seat so that the valve box side seat portion is in close contact with the valve body seat portion when the valve body is closed. And the sealing fluid pressure at the time of closing the valve body urges the bellows type valve seat so that the valve box side seat portion is in close contact with the valve body seat portion, Mounting from the axis of the bellows type valve seat to the outer end of the base in order to increase the action of the pressure applied to the bellows type valve seat as an external pressure at the time of body closing to extend the bellows type valve seat in the axial direction The valve body is in close contact with the valve body seat portion in a closed state from the radius R and the axis. Between the sealing radius R1 to Kiben box side sheet portion, and is characterized in that it has a relationship of R <R1.

前記構成によれば、弁体の閉弁時においては、ベロー型弁座の弾性付勢力による第１の作用によって、弁箱側シート部を弁体シート部に密着させて、高いシール性を確保することができる。また、弁体の閉弁によって封止される流体の圧力がベロー型弁座に負荷されると、当該ベロー型弁座を軸方向にのばすように付勢する第２の作用が生じる。この第２の作用によって、ベロー型弁座が軸方向にのばされて、弁体シート部に対する弁箱側シート部の密着力が高められることによっても、高いシール性を確保することができる。すなわち、請求項１記載の発明に係るバルブの弁座構造では、前記第１の作用に第２の作用が加算された複合的な作用によって、高いシール性を確保することができる。
さらに、弁体の閉弁時に該弁体によってベロー型弁座が過剰に押圧されたとしても、この過剰な押圧による圧縮変形は、ベロー型弁座を構成している山部と谷部の複数部位の圧縮変形に分散して吸収することができるので、ベロー型弁座の塑性変形を抑制して、弾性を維持した状態で高いシール性を確保することができる。
特に、請求項１記載の発明に係るバルブの弁座構造では、弁体閉弁時の封止流体圧がベロー型弁座に外圧として負荷され、ベロー型弁座の取付半径Ｒとシール半径Ｒ１との間に、Ｒ＜Ｒ１の関係を有しているので、Ｒ１−Ｒに相当する受圧面Δｒがベロー型弁座の山部の表面に形成され、この受圧面Δｒに相当して、封止流体圧によりベロー型弁座を軸方向にのばす作用が大きくなる。したがって、弁体シート部に対する弁箱側シート部の密着力がより一層高められ、強力なシール性を確保することができる。 According to the above configuration, when the valve body is closed, the valve box side seat portion is brought into close contact with the valve body seat portion by the first action by the elastic urging force of the bellows type valve seat to ensure high sealing performance. can do. Further, when the pressure of the fluid sealed by closing the valve body is applied to the bellows type valve seat, a second action for urging the bellows type valve seat to extend in the axial direction occurs. Due to this second action, the bellows type valve seat is extended in the axial direction, and the close contact force of the valve box side seat portion with respect to the valve body seat portion can be enhanced, thereby ensuring high sealing performance. That is, in the valve seat structure of the valve according to the first aspect of the invention, high sealing performance can be ensured by a combined action in which the second action is added to the first action.
Further, even if the bellows type valve seat is excessively pressed by the valve body when the valve body is closed, the compression deformation due to the excessive pressing is caused by a plurality of peaks and valleys constituting the bellows type valve seat. Since it can disperse | distribute and absorb in the compression deformation of a site | part, the plastic deformation of a bellows type valve seat can be suppressed, and a high sealing performance can be ensured in the state which maintained elasticity.
In particular, in the valve seat structure according to the first aspect of the present invention, the sealing fluid pressure when the valve body is closed is loaded as an external pressure on the bellows type valve seat, and the mounting radius R and the seal radius R1 of the bellows type valve seat are set. Therefore, the pressure receiving surface Δr corresponding to R1-R is formed on the surface of the peak portion of the bellows type valve seat, and the pressure receiving surface Δr The action of extending the bellows type valve seat in the axial direction is increased by the stop fluid pressure. Therefore, the adhesive force of the valve box side seat portion with respect to the valve body seat portion is further enhanced, and a strong sealing property can be secured.

また、請求項２記載の発明に係るバルブの弁座構造は、基部が弁箱側に取付けられたベロー型弁座の先端部に弁体に設けた弁体シート部に接離する弁箱側シート部が設けられ、該ベロー型弁座の弾性により付勢されて前記弁体の閉弁時に前記弁箱側シート部が前記弁体シート部に密着するように構成されているとともに、前記弁体閉弁時の封止流体圧が前記ベロー型弁座を付勢して前記弁箱側シート部を前記弁体シート部に密着させるように構成されており、前記弁体閉弁時内圧として前記ベロー型弁座に負荷される圧力が該ベロー型弁座を軸方向にのばす作用を増大させるために、前記ベロー型弁座の軸線から前記基部の外端までの取付半径Ｒと、前記軸線から前記弁体の閉弁状態で前記弁体シート部に密着している前記弁箱側シート部までのシール半径Ｒ１との間に、Ｒ１＜Ｒの関係を有していることを特徴とするものである。 Further, the valve seat structure of the valve according to the invention of claim 2 is such that the base portion is in contact with and separated from the valve body seat portion provided on the valve body at the tip of the bellows type valve seat attached to the valve box side. A seat portion is provided, and is configured to be urged by the elasticity of the bellows type valve seat so that the valve box side seat portion is in close contact with the valve body seat portion when the valve body is closed. The sealing fluid pressure at the time of closing the body is configured to urge the bellows type valve seat so that the valve box side seat portion is in close contact with the valve body seat portion. In order to increase the action of the pressure applied to the bellows type valve seat in the axial direction, the mounting radius R from the axis of the bellows type valve seat to the outer end of the base, and the axis To the valve box side seat part that is in close contact with the valve body seat part when the valve body is closed. Between the sealing radius R1 of, it is characterized in that it has a relationship of R1 <R.

前記構成によれば、弁体の閉弁時においては、ベロー型弁座の弾性付勢力による第１の作用によって、弁箱側シート部を弁体シート部に密着させて、高いシール性を確保することができる。また、弁体の閉弁によって封止される流体の圧力がベロー型弁座に負荷されると、当該ベロー型弁座を軸方向にのばすように付勢する第２の作用が生じる。この第２の作用によって、ベロー型弁座が軸方向にのばされて、弁体シート部に対する弁箱側シート部の密着力が高められることによっても、高いシール性を確保することができる。すなわち、請求項２に係る発明のバルブの弁座構造では、前記第１の作用に第２の作用が加算された複合的な作用によって、高いシール性を確保することができる。
さらに、弁体の閉弁時に該弁体によってベロー型弁座が過剰に押圧されたとしても、この過剰な押圧による圧縮変形は、ベロー型弁座を構成している山部と谷部の複数部位の圧縮変形に分散して吸収することができるので、ベロー型弁座の塑性変形を抑制して、弾性を維持した状態で高いシール性を確保することができる。
特に、請求項２記載の発明に係るバルブの弁座構造では、弁体閉弁時の封止流体圧がベロー型弁座に内圧として負荷され、ベロー型弁座の取付半径Ｒとシール半径Ｒ１との間に、Ｒ１＜Ｒの関係を有しているので、Ｒ−Ｒ１に相当する受圧面Δｒがベロー型弁座の山部の表面に形成され、この受圧面Δｒに相当して、封止流体圧によりベロー型弁座を軸方向にのばす作用が大きくなる。したがって、弁体シート部に対する弁箱側シート部の密着力がより一層高められ、強力なシール性を確保することができる。 According to the above configuration, when the valve body is closed, the valve box side seat portion is brought into close contact with the valve body seat portion by the first action by the elastic urging force of the bellows type valve seat to ensure high sealing performance. can do. Further, when the pressure of the fluid sealed by closing the valve body is applied to the bellows type valve seat, a second action for urging the bellows type valve seat to extend in the axial direction occurs. Due to this second action, the bellows type valve seat is extended in the axial direction, and the close contact force of the valve box side seat portion with respect to the valve body seat portion can be enhanced, thereby ensuring high sealing performance. That is, in the valve seat structure of the valve according to the second aspect of the invention, high sealing performance can be ensured by the combined action in which the second action is added to the first action.
Further, even if the bellows type valve seat is excessively pressed by the valve body when the valve body is closed, the compression deformation due to the excessive pressing is caused by a plurality of peaks and valleys constituting the bellows type valve seat. Since it can disperse | distribute and absorb in the compression deformation of a site | part, the plastic deformation of a bellows type valve seat can be suppressed, and a high sealing performance can be ensured in the state which maintained elasticity.
In particular, in the valve seat structure of the valve according to the second aspect of the invention, the sealing fluid pressure when the valve body is closed is loaded as an internal pressure on the bellows type valve seat, and the mounting radius R and the seal radius R1 of the bellows type valve seat are set. Therefore, the pressure receiving surface Δr corresponding to R-R1 is formed on the surface of the peak portion of the bellows type valve seat, and the pressure receiving surface Δr The action of extending the bellows type valve seat in the axial direction is increased by the stop fluid pressure. Therefore, the adhesive force of the valve box side seat portion with respect to the valve body seat portion is further enhanced, and a strong sealing property can be secured.

請求項３記載の発明に係るバルブの弁座構造は、請求項１又は請求項２記載の発明に係るバルブの弁座構造に、弁体を回転弁体によって構成し、この回転弁体には、ベロー型弁座の弁箱側シート部に接離する凹球面状の弁体シート部を設けるという構成を付加したものである。これによると、請求項１又は請求項２記載の発明に係るバルブの弁座構造を内面シール構造の回転弁に適用することができる。 A valve seat structure for a valve according to a third aspect of the present invention is the valve seat structure for a valve according to the first or second aspect of the present invention, wherein the valve body is constituted by a rotary valve body. In addition, a configuration is provided in which a concave spherical valve body seat portion that is in contact with and separated from the valve box side seat portion of the bellows type valve seat is provided. According to this, the valve seat structure of the valve according to the first or second aspect of the invention can be applied to a rotary valve having an inner surface seal structure.

請求項４記載の発明に係るバルブの弁座構造は、請求項３記載の発明に係るバルブの弁座構造に、ベロー型弁座の基部側の弁箱に、当該ベロー型弁座を開閉するバタフライ弁を内蔵するという構成を付加したものである。これによると、請求項１乃至請求項３記載の発明に係るバルブの弁座構造を、たとえば、粉体を搬送ガスによって移送する管路系に装着される複合弁に適用することができる。 A valve seat structure for a valve according to a fourth aspect of the present invention opens and closes the bellows type valve seat in a valve box on the base side of the bellows type valve seat in the valve seat structure of the valve according to the third aspect of the invention. A configuration in which a butterfly valve is incorporated is added. According to this, the valve seat structure according to the first to third aspects of the invention can be applied to, for example, a composite valve mounted on a pipeline system that transfers powder by carrier gas.

本発明によれば、ベロー型弁座の塑性変形が抑制されることによって、ベロー型弁座の弾性による付勢力を長期間維持して、弁箱側シート部を弁体シート部に密着させて、高いシール性を確保することができる。また、弁体閉弁時の封止流体圧で弁箱側シート部を弁体シート部に密着させて、高いシール性を確保することができる。 According to the present invention, by restraining the plastic deformation of the bellows type valve seat, the urging force due to the elasticity of the bellows type valve seat is maintained for a long period of time, and the valve box side seat portion is brought into close contact with the valve body seat portion. High sealing performance can be ensured. In addition, the valve box side seat can be brought into close contact with the valve seat by the sealing fluid pressure when the valve is closed, thereby ensuring high sealing performance.

図１は本発明を内面シール構造の回転弁に適用した実施形態を示す縦断面図である。この図において、内面シール構造の回転弁Ｖは、弁箱２０の上端部に流入口２０ａを有し、弁箱２０の下端部に流出口２０ｂを同心で備えている。弁箱２０には、流入口２０ａおよび流出口２０ｂと同心に弁箱スリーブ２１が収容されており、その基端部２１ａが弁箱２０に固着され先端部２１ｂは流出口２０ｂに向かって開口している。 FIG. 1 is a longitudinal sectional view showing an embodiment in which the present invention is applied to a rotary valve having an internal seal structure. In this figure, the rotary valve V having an inner seal structure has an inlet 20 a at the upper end of the valve box 20 and a concentric outlet 20 b at the lower end of the valve box 20. A valve box sleeve 21 is accommodated in the valve box 20 concentrically with the inlet 20a and the outlet 20b. The base end 21a is fixed to the valve box 20, and the distal end 21b opens toward the outlet 20b. ing.

弁箱スリーブ２１の内部には、スリーブ内流路２１Ａを開閉するバタフライ弁２２が配置され、弁箱スリーブ２１の先端部２１ｂは、凹球面状の弁体シート部２３を裏面に形成した回転弁体２４の９０度回転によって開閉される。なお、バタフライ弁２２を軸支するバタフライ弁用弁棒２５は、弁箱２０の一方の側面を気密かつ回転自在に貫通してバタフライ弁開閉手段（図示省略）に接続され、回転弁体２４を軸支する回転弁体用弁棒２６は、弁箱２０の他方の側面を気密かつ回転自在に貫通して回転弁開閉手段（図示省略）に接続されている。 Inside the valve box sleeve 21, a butterfly valve 22 for opening and closing the in-sleeve flow path 21A is arranged, and the tip 21b of the valve box sleeve 21 is a rotary valve formed with a concave spherical valve body seat portion 23 on the back surface. The body 24 is opened and closed by rotating 90 degrees. A butterfly valve valve rod 25 that pivotally supports the butterfly valve 22 passes through one side surface of the valve box 20 in an airtight and rotatable manner and is connected to a butterfly valve opening / closing means (not shown). The rotary valve body valve rod 26 that is pivotally supported is airtight and rotatable through the other side surface of the valve box 20, and is connected to a rotary valve opening / closing means (not shown).

弁箱スリーブ２１の先端部２１ｂには、ベロー型弁座２７が取付けられている。このベロー型弁座２７は、コバルト基合金、ニッケル基合金、クロム基合金などの耐熱・耐摩耗性にすぐれた金属によって構成されている。そして、図２に示すように、径内方向に縮径している谷部２７ａと径外方向に拡径している山部２７ｂの複数部位が軸方向に連続しており、基部２８がボルト２９を介して弁箱スリーブ２１の先端部２１ｂに同心に取付けられ、先端部には回転弁体２４の裏面に形成した凹球面状の弁体シート部２３に接離する弁箱側シート部３０を設けてある。このように、ベロー型弁座２７をコバルト基合金、ニッケル基合金、クロム基合金などの耐熱・耐摩耗性にすぐれた金属によって構成していることによって、高温下での使用が可能になって、ベロー型弁座２７の適用範囲を拡大することができるとともに、弁箱側シート部３０の摩耗に伴うシール性の低下を抑えて、バルブの弁座構造の耐久性を向上させることができる。 A bellows type valve seat 27 is attached to the distal end portion 21 b of the valve box sleeve 21. The bellows type valve seat 27 is made of a metal having excellent heat resistance and wear resistance, such as a cobalt base alloy, a nickel base alloy, and a chromium base alloy. As shown in FIG. 2, a plurality of portions of a valley portion 27 a that is reduced in the radial direction and a peak portion 27 b that is expanded in the radial direction are continuous in the axial direction, and the base portion 28 is a bolt. 29 is attached concentrically to the distal end portion 21 b of the valve box sleeve 21 via 29, and at the distal end portion, a valve box side seat portion 30 that contacts and separates from a concave spherical valve body seat portion 23 formed on the back surface of the rotary valve body 24. Is provided. As described above, the bellows type valve seat 27 is made of a metal having excellent heat resistance and wear resistance, such as a cobalt base alloy, a nickel base alloy, and a chromium base alloy, so that it can be used at a high temperature. In addition, the applicable range of the bellows type valve seat 27 can be expanded, and the deterioration of the sealing performance accompanying wear of the valve box side seat portion 30 can be suppressed, and the durability of the valve seat structure of the valve can be improved.

一方、ベロー型弁座２７の弁箱側シート部３０には、耐熱・耐摩耗性にすぐれたステライトなどの超硬合金からなる肉盛り部３１を設け、この肉盛り部３１によって弁箱側シート部３０を構成している。したがって、弁箱側シート部３０の熱劣化に伴うシール性の低下を抑えて、バルブの弁座構造の耐久性をより一層向上させることができるとともに、弁箱側シート部３０の摩耗に伴うシール性の低下をより一層確実に抑えて、バルブの弁座構造の耐久性をさらに向上させることができる。 On the other hand, the valve box side seat portion 30 of the bellows type valve seat 27 is provided with a built-up portion 31 made of a cemented carbide such as stellite having excellent heat resistance and wear resistance. Part 30 is configured. Therefore, it is possible to further suppress the deterioration of the valve seat structure due to thermal deterioration of the valve box side seat portion 30 and to further improve the durability of the valve seat structure. It is possible to further improve the durability of the valve seat structure of the valve by further reliably suppressing the deterioration of the performance.

また、図１，図２，図３に示すように、ベロー型弁座２７の軸線Ｃ（なお、この軸線Ｃは、本実施形態においては弁箱２０および弁箱スリーブ２１の軸線と同じである）から基部２８の外端までの取付半径Ｒと、前記軸線Ｃから回転弁体２４の閉弁状態で凹球面状の弁体シート部２３に密着している肉盛り部３１（弁箱側シート部３０）までのシール半径Ｒ１との関係を、Ｒ≦Ｒ１好ましくはＲ＜Ｒ１に設定してある。つまり、図２の参考例ではＲ＝Ｒ１に設定され、図３の実施形態ではＲ＜Ｒ１に設定してある。 1, 2 and 3, the axis C of the bellows type valve seat 27 (this axis C is the same as the axes of the valve box 20 and the valve box sleeve 21 in the present embodiment). ) To the outer end of the base portion 28, and a built-up portion 31 (valve box side seat) that is in close contact with the concave spherical valve body seat portion 23 when the rotary valve body 24 is closed from the axis C. The relationship with the seal radius R1 up to the portion 30) is set to R ≦ R1, preferably R <R1. That is, R = R1 is set in the reference example of FIG. 2, and R <R1 is set in the embodiment of FIG.

前記構成において、内面シール構造の回転弁Ｖは、弁箱２０の流入口２０ａを粉体の供給系に接続するとともに、流出口２０ｂを高圧の搬送ガスが流れる搬送系に接続して使用される。なお、粉体を伴って流れる搬送系の途中に介設することも可能である。 In the above-described configuration, the rotary valve V having an inner seal structure is used by connecting the inlet 20a of the valve box 20 to a powder supply system and connecting the outlet 20b to a carrier system through which high-pressure carrier gas flows. . It is also possible to intervene in the middle of the conveyance system that flows with the powder.

回転弁Ｖの開弁操作は、まず、回転弁体２４を図１の実線で示す位置から二点鎖線で示す位置に９０度回転させて開弁し、その後にバタフライ弁２２を実線で示す位置から二点鎖線で示す位置に９０度回転させて開弁する手順によってなされる。この状態で、粉体は弁箱２０の流入口２０ａから弁箱スリーブ２１を通って自重で落下し、流出口２０ｂを経て搬送系に流入する。 In the opening operation of the rotary valve V, first, the rotary valve body 24 is rotated 90 degrees from the position indicated by the solid line in FIG. 1 to the position indicated by the two-dot chain line, and then the butterfly valve 22 is indicated by the solid line. To 90 ° to the position indicated by the two-dot chain line. In this state, the powder falls by its own weight from the inlet 20a of the valve box 20 through the valve box sleeve 21 and flows into the conveying system through the outlet 20b.

回転弁Ｖの閉弁操作は、まず、バタフライ弁２２を二点鎖線で示す位置から実線で示す位置に９０度逆回転させて粉体の流れを遮断し、ベロー型弁座２７の周囲に粉体が存在しない状態で、回転弁体２４を二点鎖線で示す位置から実線で示す位置に９０度逆回転させて閉弁する手順によってなされる。このことにより、ベロー型弁座２７の肉盛り部３１（弁箱側シート部３０）と回転弁体２４の凹球面状の弁体シート部２３との間に粉体が噛み込むのを防止して、シール性を確実なものにすることができる。 To close the rotary valve V, first, the butterfly valve 22 is reversely rotated 90 degrees from the position indicated by the two-dot chain line to the position indicated by the solid line to block the powder flow, and the powder flow around the bellows type valve seat 27 is reduced. In a state where no body is present, the rotary valve body 24 is reversely rotated 90 degrees from the position indicated by the two-dot chain line to the position indicated by the solid line to close the valve. This prevents powder from getting caught between the built-up portion 31 (valve box side seat portion 30) of the bellows type valve seat 27 and the concave spherical valve body seat portion 23 of the rotary valve body 24. Thus, the sealing performance can be ensured.

図２に示す参考例において、回転弁体２４の閉弁時には、ベロー型弁座２７の弾性付勢力によって、肉盛り部３１（弁箱側シート部３０）を回転弁体２４の凹球面状の弁体シート部２３に密着させて、高いシール性を確保することができる。また、回転弁体２４の閉弁時には、前記搬送系を流れている搬送ガスの圧力Ｐがベロー型弁座２７に外圧として負荷される。そして、取付半径Ｒとシール半径Ｒ１との関係がＲ＝Ｒ１に設定され、かつ谷部２７ｃのくぼみ量よりも大きいくぼみ量を保有している谷部２７ａに圧力Ｐが外圧として負荷されて、ベロー型弁座２７を軸方向にのばすように付勢する作用が生じるので［なお、くぼみ量とは、くぼみの径方向の寸法「くぼみの深さ」およびくぼみの円周方向の長さ「くぼみの幅」の少なくともいずれか一方のことをいう］、この作用によって、ベロー型弁座２７が軸方向にのばされて（軸方向に撓んで）、弁体シート部２３に対する弁箱側シート部３０の密着力が高められることによっても、高いシール性を確保することができる。すなわち、図２の参考例では、ベロー型弁座２７は、自己の弾性付勢力によって、肉盛り部３１（弁箱側シート部３０）を回転弁体２４の凹球面状の弁体シート部２３に密着させる作用に加えて、外圧Ｐによってベロー型弁座２７が軸方向にのばされて、肉盛り部３１（弁箱側シート部３０）を回転弁体２４の凹球面状の弁体シート部２３に密着させる作用が加算される複合的な作用によって、高いシール性を確保することができる。 In the reference example shown in FIG. 2, when the rotary valve body 24 is closed, the built-up portion 31 (the valve box side seat portion 30) is formed into the concave spherical shape of the rotary valve body 24 by the elastic biasing force of the bellows type valve seat 27. It is possible to ensure high sealing performance by closely contacting the valve body seat portion 23. Further, when the rotary valve body 24 is closed, the pressure P of the carrier gas flowing through the carrier system is loaded on the bellows type valve seat 27 as an external pressure. Then, the relationship between the mounting radius R and the seal radius R1 is set to R = R1, and the pressure P is applied as an external pressure to the trough portion 27a that has a recess amount larger than the recess amount of the trough portion 27c. Since the action of energizing the bellows type valve seat 27 so as to extend in the axial direction occurs, [the indentation amount is the indentation radial dimension “indentation depth” and the indentation circumferential length “indentation”. This means that the bellows type valve seat 27 is extended in the axial direction (bends in the axial direction) by this action, and the valve box side seat portion with respect to the valve body seat portion 23. High sealing performance can be ensured by increasing the adhesion of 30. That is, in the reference example of FIG. 2, the bellows type valve seat 27 is formed by the elastic biasing force of the bellows type valve seat 27 with the built-up portion 31 (valve box side seat portion 30) of the concave spherical valve body seat portion 23. In addition to the action of bringing the bellows type valve seat 27 into the axial direction by the external pressure P, the valve section seat of the concave spherical surface of the rotary valve body 24 is formed by extending the built-up portion 31 (valve box side seat portion 30). A high sealing performance can be ensured by a combined action in which the action of closely contacting the portion 23 is added.

一方、図３に示す実施形態のように、ベロー型弁座２７の取付半径Ｒとシール半径Ｒ１との関係をＲ＜Ｒ１に設定すると、Ｒ１−Ｒに相当する受圧面Δｒが山部２７ｂの表面に形成され、この受圧面Δｒに相当して、外圧Ｐによりベロー型弁座２７を軸方向にのばす作用が図２の参考例よりも大きくなる。したがって、ベロー型弁座２７は、自己の弾性付勢力と、受圧面Δｒが確保されたことによって、図２の参考例よりも強力に軸方向にのばされて（軸方向に撓んで）、弁体シート部２３に対する弁箱側シート部３０の密着力がより一層高められることによっても、図２に示す参考例よりも強力なシール性を確保することができる。 On the other hand, when the relationship between the attachment radius R of the bellows type valve seat 27 and the seal radius R1 is set to R <R1 as in the embodiment shown in FIG. 3, the pressure receiving surface Δr corresponding to R1-R is the peak portion 27b. Corresponding to the pressure receiving surface Δr formed on the surface, the action of extending the bellows type valve seat 27 in the axial direction by the external pressure P becomes larger than the reference example of FIG. Therefore, the bellows type valve seat 27 is extended in the axial direction more strongly than the reference example of FIG. 2 (bends in the axial direction) by securing its own elastic urging force and pressure receiving surface Δr. A stronger sealing property than that of the reference example shown in FIG. 2 can also be secured by further increasing the adhesion of the valve box side seat portion 30 to the valve body seat portion 23.

また、図１，図２，図３に示す回転弁体２４の閉弁時において、搬送ガスの圧力Ｐが回転弁体２４の表面に作用して、ベロー型弁座２７が過剰に弁箱スリーブ２１側に押圧されたとしても、この過剰な押圧によるベロー型弁座２７の圧縮変形は、ベロー型弁座２７を構成している山部２７ｂと谷部２７ａ，２７ｃの複数部位の圧縮変形に分散して吸収することができるので、ベロー型弁座２７の塑性変形が抑制されて弾性を維持できる。このため、維持された弾性付勢力によって肉盛り部３１（弁箱側シート部３０）を回転弁体２４の凹球面状の弁体側シート部２３に密着させて、高いシール性を確保することができる。 Further, when the rotary valve body 24 shown in FIGS. 1, 2 and 3 is closed, the pressure P of the carrier gas acts on the surface of the rotary valve body 24, and the bellows type valve seat 27 excessively forms the valve box sleeve. Even if pressed to the side 21, the compression deformation of the bellows type valve seat 27 due to this excessive pressing results in compression deformation of a plurality of portions of the peak portion 27b and the valley portions 27a, 27c constituting the bellows type valve seat 27. Since it can be dispersed and absorbed, plastic deformation of the bellows type valve seat 27 is suppressed and elasticity can be maintained. For this reason, it is possible to secure the high sealing performance by bringing the built-up portion 31 (valve box side seat portion 30) into close contact with the concave spherical valve body side seat portion 23 of the rotary valve body 24 by the maintained elastic biasing force. it can.

さらに、搬送ガスの圧力Ｐが回転弁体２４の表面に作用していない状態であれば、回転弁体２４の閉弁時において、回転弁体２４の自重および該回転弁体２４を取付けている回転弁体用弁棒２６と軸受（図示省略）との間に生じる軸受隙間の影響で、軸受隙間分に相当して回転弁体２４が下降する。しかし、前述の理由により、ベロー型弁座２７の塑性変形が抑制されることで維持されている弾性付勢力によって、軸受隙間分に相当する回転弁体２４の下降を補償して、肉盛り部３１（弁箱側シート部３０）を回転弁体２４の凹球面状の弁体シート部２３に密着させて、高いシール性を確保することができる。 Further, if the pressure P of the carrier gas does not act on the surface of the rotary valve body 24, the weight of the rotary valve body 24 and the rotary valve body 24 are attached when the rotary valve body 24 is closed. Due to the influence of the bearing gap generated between the rotary valve element valve stem 26 and the bearing (not shown), the rotary valve element 24 is lowered corresponding to the bearing gap. However, for the reasons described above, the lowering of the rotary valve body 24 corresponding to the bearing gap is compensated by the elastic biasing force maintained by suppressing the plastic deformation of the bellows type valve seat 27, and the built-up portion 31 (valve box side seat portion 30) can be brought into close contact with the concave spherical valve body seat portion 23 of the rotary valve body 24 to ensure high sealing performance.

なお、図３に示す実施形態では、回転弁体２４の閉弁時において、搬送ガスの圧力Ｐが外圧としてベロー型弁座２７に負荷される構成で説明しているが、ガス圧Ｐ１が内圧としてベロー型弁座２７に負荷される場合は、ベロー型弁座２７の取付半径Ｒとシール半径Ｒ１との関係をＲ＞Ｒ１に設定することによって、内圧Ｐ１によりベロー型弁座２７を軸方向にのばす作用が生じて、肉盛り部３１（弁箱側シート部３０）を回転弁体２４の凹球面状の弁体シート部２３に密着させることができる。 In the embodiment shown in FIG. 3, the structure is described in which the pressure P of the carrier gas is loaded on the bellows type valve seat 27 as the external pressure when the rotary valve body 24 is closed, but the gas pressure P1 is the internal pressure. When the bellows type valve seat 27 is loaded, the relationship between the mounting radius R of the bellows type valve seat 27 and the seal radius R1 is set to R> R1 , so that the bellows type valve seat 27 is axially moved by the internal pressure P1. Thus, the build-up portion 31 (valve box side seat portion 30) can be brought into close contact with the concave spherical valve body seat portion 23 of the rotary valve body 24.

本発明に係るバルブの弁座構造は、図４，図５に示すように、外面シール構造のボール弁Ｖ１に適用することができる。図４において、流入口２０ａと流出口２０ｂを設けた弁箱２０には、該弁箱２０の軸線Ｃに直交する軸線Ｃ１をもつ弁棒３２を備え、この弁棒３２とともに軸線Ｃ１まわりに回転する球状の弁体３３が収容されており、この球状の弁体３３における軸線Ｃ方向の両側の二つの位置にベロー型弁座２７を配置して、それぞれの肉盛り部３１（弁箱側シート部３０）を球状の弁体３３の表面を構成する凸球面状の弁体シート部２３に密着させてある。そして、図５に示すように、ベロー型弁座２７の取付半径Ｒとシール半径Ｒ１との関係をＲ＜Ｒ１に設定して、Ｒ１−Ｒに相当する受圧面Δｒを設けてある。 The valve seat structure of the valve according to the present invention can be applied to a ball valve V1 having an outer seal structure as shown in FIGS. In FIG. 4, a valve box 20 provided with an inlet 20a and an outlet 20b is provided with a valve rod 32 having an axis C1 perpendicular to the axis C of the valve box 20, and rotates around the axis C1 together with the valve rod 32. The spherical valve body 33 is accommodated, and bellows type valve seats 27 are arranged at two positions on both sides of the spherical valve body 33 in the direction of the axis C, and the respective built-up portions 31 (valve box side seats). The portion 30) is closely attached to the convex spherical valve body sheet portion 23 constituting the surface of the spherical valve body 33. As shown in FIG. 5, the relationship between the mounting radius R of the bellows type valve seat 27 and the seal radius R1 is set to R <R1, and a pressure receiving surface Δr corresponding to R1-R is provided .

図５のように、弁体３３が閉弁されている状態で、流入口２０ａに流体圧Ｐが作用すると、この流体圧Ｐは、内圧として上流側のベロー型弁座２７の内面に負荷されて、上流側のベロー型弁座２７を軸方向に短縮させるように付勢する作用が生じるので、この作用によって、上流側のベロー型弁座２７が軸方向に僅かに短縮して（軸方向に撓んで）、凸球面状の弁体シート部２３に対する肉盛り部３１（弁箱側シート部３０）の密着力を低下させることになる。このため、流体圧Ｐは、矢印Ｐ１，Ｐ２で示すように、凸球面状の弁体シート部２３と肉盛り部３１（弁箱側シート部３０）との間を通って、下流側のベロー型弁座２７の表面に負荷されることになる。その結果、前述した理由によって、下流側のベロー型弁座２７は軸方向にのばされて（軸方向に撓んで）、弁体シート部２３に対する弁箱側シート部３０の密着力が高められるので、下流側のベロー型弁座２７によって、高いシール性を確保することができる。 As shown in FIG. 5, when the fluid pressure P acts on the inflow port 20a with the valve body 33 closed, the fluid pressure P is loaded as an internal pressure on the inner surface of the bellows type valve seat 27 on the upstream side. As a result, the upstream bellows type valve seat 27 is biased so as to be shortened in the axial direction, so that the upstream side bellows type valve seat 27 is slightly shortened in the axial direction (axial direction). And the adhesion force of the built-up portion 31 (valve box side sheet portion 30) to the convex spherical valve body sheet portion 23 is reduced. For this reason, as shown by arrows P1 and P2, the fluid pressure P passes between the convex spherical valve body seat portion 23 and the built-up portion 31 (valve box side seat portion 30), and then the bellows on the downstream side. The surface of the mold valve seat 27 is loaded. As a result, for the reasons described above, the downstream bellows type valve seat 27 is extended in the axial direction (bends in the axial direction), and the adhesion of the valve box side seat portion 30 to the valve body seat portion 23 is enhanced. Therefore, high sealing performance can be secured by the bellows type valve seat 27 on the downstream side.

一方、弁棒３２と軸受（図示省略）との間に生じる軸受隙間の影響で、軸受隙間分に相当して球状の弁体３３が流出口２０ｂの方向に僅かに変位したとしても、この変位は、上流側のベロー型弁座２７の弾性によって補償され、その肉盛り部３１（弁箱側シート部３０）を球状の弁体３３表面の球面状の弁体シート部２３に密着させて、高いシール性を確保することができる。このように、球状の弁体３３が流出口２０ｂの方向に僅かに変位することで、下流側のベロー型弁座２７が過剰に流出口２０ｂ側に押圧されたとしても、この過剰な押圧による下流側のベロー型弁座２７の圧縮変形は、ベロー型弁座２７を構成している山部２７ｂと谷部２７ａ，２７ｃの複数部位の圧縮変形に分散して吸収することができるので、下流側のベロー型弁座２７の塑性変形が抑制されて弾性を維持できることになる。したがって、この弾性付勢力によって肉盛り部３１（弁箱側シート部３０）を球状の弁体３３表面の球面状の弁体シート部２３に密着させて、高いシール性を確保することができる。 On the other hand, even if the spherical valve element 33 is slightly displaced in the direction of the outlet 20b corresponding to the bearing gap due to the influence of the bearing gap generated between the valve stem 32 and the bearing (not shown), this displacement Is compensated by the elasticity of the upstream bellows type valve seat 27, and the build-up portion 31 (valve box side seat portion 30) is brought into close contact with the spherical valve body seat portion 23 on the surface of the spherical valve body 33, High sealing performance can be secured. Thus, even if the downstream bellows type valve seat 27 is excessively pressed toward the outlet 20b by the slight displacement of the spherical valve body 33 in the direction of the outlet 20b, Since the compressive deformation of the bellows type valve seat 27 on the downstream side can be dispersed and absorbed in the compressive deformation of a plurality of portions of the peak portion 27b and the valley portions 27a and 27c constituting the bellows type valve seat 27, the downstream The plastic deformation of the side bellows type valve seat 27 is suppressed, and the elasticity can be maintained. Therefore, it is possible to ensure high sealing performance by bringing the build-up portion 31 (valve box side seat portion 30) into close contact with the spherical valve body seat portion 23 on the surface of the spherical valve body 33 by this elastic biasing force.

なお、球状の弁体３３が閉弁されている状態で、流体圧Ｐ１が流出口２０ｂから球状の弁体３３に負荷された場合は、前記上流側のベロー型弁座２７と下流側のベロー型弁座２７は、前述した流体圧Ｐが流入口２０ａから球状の弁体３３に負荷される場合の逆に作用することのなるので、流体圧Ｐ１が流出口２０ｂから球状の弁体３３に負荷された場合の作用説明は省略する。 When the spherical pressure body 33 is closed and the fluid pressure P1 is applied to the spherical valve body 33 from the outlet 20b, the upstream bellows type valve seat 27 and the downstream bellows The mold valve seat 27 acts oppositely to the case where the aforementioned fluid pressure P is applied to the spherical valve body 33 from the inflow port 20a. Therefore, the fluid pressure P1 is applied to the spherical valve body 33 from the outflow port 20b. The explanation of the operation when loaded is omitted.

本発明を内面シール構造の回転弁に適用した実施形態を示す縦断面図である。It is a longitudinal cross-sectional view which shows embodiment which applied this invention to the rotary valve of the inner surface seal structure. ベロー型弁座の参考例の一部を拡大して示す縦断面図である。It is a longitudinal cross-sectional view which expands and shows a part of reference example of a bellows type valve seat. ベロー型弁座の実施形態の一部を拡大して示す縦断面図である。It is a longitudinal sectional view showing an enlarged part of the implementation form of bellows-type valve seat. 本発明を外面シール構造のボール弁に適用した実施形態を示す縦断面図である。It is a longitudinal cross-sectional view which shows embodiment which applied this invention to the ball valve of an outer surface seal structure. ボール弁に適用した場合のシール作用の説明図である。It is explanatory drawing of the sealing effect | action at the time of applying to a ball valve. 第１従来例の縦断面図である。It is a longitudinal cross-sectional view of a 1st prior art example. 第２従来例の縦断面図である。It is a longitudinal cross-sectional view of a 2nd prior art example.

２０弁箱
２２バタフライ弁
２３凹球面状の弁体シート部（複合弁の弁体シート部）
２４回転弁体（複合弁の弁体）
２７ベロー型弁座
２８ベロー型弁座の基部
３０弁箱側シート部（ベロー型弁座のシート部）
３３球状の弁体（ボール弁の弁体）
３４球面状の弁体シート部（ボール弁の弁体シート部） 20 Valve box 22 Butterfly valve 23 Concave spherical valve body seat (valve seat of composite valve)
Rotating valve body (composite valve body)
27 Bellows type valve seat 28 Base part of bellows type valve seat 30 Valve box side seat part (seat part of bellows type valve seat)
33 Spherical valve body (Ball valve body)
34 Spherical valve seat (ball valve seat)

Claims

基部が弁箱側に取付けられたベロー型弁座の先端部に弁体に設けた弁体シート部に接離する弁箱側シート部が設けられ、該ベロー型弁座の弾性により付勢されて前記弁体の閉弁時に前記弁箱側シート部が前記弁体シート部に密着するように構成されているとともに、前記弁体閉弁時の封止流体圧が前記ベロー型弁座を付勢して前記弁箱側シート部を前記弁体シート部に密着させるように構成されており、前記弁体閉弁時外圧として前記ベロー型弁座に負荷される圧力が該ベロー型弁座を軸方向にのばす作用を増大させるために、前記ベロー型弁座の軸線から前記基部の外端までの取付半径Ｒと、前記軸線から前記弁体の閉弁状態で前記弁体シート部に密着している前記弁箱側シート部までのシール半径Ｒ１との間に、Ｒ＜Ｒ１の関係を有していることを特徴とするバルブの弁座構造。 A valve box side seat portion that comes in contact with and separates from the valve body seat portion provided on the valve body is provided at the tip of the bellows type valve seat whose base is attached to the valve box side, and is energized by the elasticity of the bellow type valve seat. The valve box side seat portion is in close contact with the valve body seat portion when the valve body is closed, and the sealing fluid pressure when the valve body is closed attaches the bellows type valve seat. The valve box side seat portion is configured to closely contact the valve body seat portion, and the pressure applied to the bellows type valve seat as the external pressure when the valve body is closed causes the bellow type valve seat to In order to increase the extending action in the axial direction, the mounting radius R from the axial line of the bellows type valve seat to the outer end of the base part, and the valve body seat part in close contact with the valve body from the axis line in the closed state. R <R1 in relation to the seal radius R1 to the valve box side seat portion A valve seat structure of the valve, characterized in that that.

基部が弁箱側に取付けられたベロー型弁座の先端部に弁体に設けた弁体シート部に接離する弁箱側シート部が設けられ、該ベロー型弁座の弾性により付勢されて前記弁体の閉弁時に前記弁箱側シート部が前記弁体シート部に密着するように構成されているとともに、前記弁体閉弁時の封止流体圧が前記ベロー型弁座を付勢して前記弁箱側シート部を前記弁体シート部に密着させるように構成されており、前記弁体閉弁時内圧として前記ベロー型弁座に負荷される圧力が該ベロー型弁座を軸方向にのばす作用を増大させるために、前記ベロー型弁座の軸線から前記基部の外端までの取付半径Ｒと、前記軸線から前記弁体の閉弁状態で前記弁体シート部に密着している前記弁箱側シート部までのシール半径Ｒ１との間に、Ｒ１＜Ｒの関係を有していることを特徴とするバルブの弁座構造。A valve box side seat portion that comes in contact with and separates from the valve body seat portion provided on the valve body is provided at the tip of the bellows type valve seat whose base is attached to the valve box side, and is energized by the elasticity of the bellow type valve seat. The valve box side seat portion is in close contact with the valve body seat portion when the valve body is closed, and the sealing fluid pressure when the valve body is closed attaches the bellows type valve seat. The valve box side seat portion is configured to closely contact the valve body seat portion, and the pressure applied to the bellows type valve seat as the internal pressure when the valve body is closed causes the bellow type valve seat to In order to increase the extending action in the axial direction, the mounting radius R from the axial line of the bellows type valve seat to the outer end of the base part, and the valve body seat part in close contact with the valve body from the axis line in the closed state. R1 <R between the seal radius R1 and the valve box side seat portion. A valve seat structure of the valve, characterized in Rukoto.

請求項１又は請求項２に記載のバルブの弁座構造において、
前記弁体が回転弁体によって構成され、この回転弁体には、前記ベロー型弁座の弁箱側シート部に接離する凹球面状の弁体シート部が設けられていることを特徴とするバルブの弁座構造。 In the valve seat structure of the valve according to claim 1 or 2 ,
The valve body is constituted by a rotary valve body, and the rotary valve body is provided with a concave spherical valve body seat portion that contacts and separates from a valve box side seat portion of the bellows type valve seat. Valve seat structure to perform.

請求項３に記載のバルブの弁座構造において、
前記ベロー型弁座の基部側の弁箱に、当該ベロー型弁座を開閉するバタフライ弁が内蔵されていることを特徴とするバルブの弁座構造。 In the valve seat structure of the valve according to claim 3 ,
A valve seat structure for a valve, wherein a butterfly valve for opening and closing the bellows type valve seat is incorporated in a valve box on a base side of the bellows type valve seat.