JP2016114116A - Ball valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To always maintain an elastic body seal in a stable state, by preventing the entry of a fluid to a back surface side of the elastic body seal.SOLUTION: A ball valve 1 includes: a valve body 6 which has channel portions 3 and 4 in which a fluid 2 flows inside, and a valve body storing space 5 provided in the midway of the channel portions 3 and 4; a ball-shaped valve body 8 installed in the inside of the valve storing space 5, and rotation-operated by an operating portion; a communication hole 9 formed on the ball-shaped valve body 8, and capable of communicating the channel portions 3 and 4 on both sides of the valve storing space 5; and elastic body seals 13 and 14 installed at boundary parts between the valve body storing space 5 and the channel portions 3 and 4, and press-contacted with a spherical surface portion 11 of the ball-shaped valve body 8. The elastic body seal 13 is provided with an entry preventive portion capable of preventing the entry of the fluid 2 to a back surface side.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a ball valve.

  Conventionally, a ball valve has been widely used to adjust the flow of fluid (see, for example, Patent Document 1).

  In this ball valve, a ball-shaped valve body having a communication hole is installed inside the valve body. The valve body is formed with a valve body housing space for housing the ball-shaped valve body and a flow path portion that can communicate with the communication hole of the ball-shaped valve body. An elastic seal that is pressed against the spherical surface of the ball-shaped valve element is installed at the boundary between the valve element accommodating space and the flow path. Then, the ball-shaped valve body is rotated by the operation section provided on the ball-shaped valve body, and the communication hole is communicated with the flow path section, so that the ball valve is opened and fluid can flow. . Further, the ball-shaped valve element is rotated in the opposite direction by the operation unit so that the communication hole is not communicated with the flow path unit, so that the ball valve can be closed and the fluid flow can be stopped. .

Japanese Patent No. 3815669

However, the ball valve has the following problems.
That is, in the ball-shaped valve body, at least the opening portion of the communication hole is not a spherical portion. Therefore, when the opening of the communication hole crosses the position of the elastic seal in the middle of opening and closing the ball valve, the elastic seal is partially separated from the spherical surface of the ball-shaped valve.

  Then, since the pressure contact force against the spherical surface portion does not act on the portion away from the spherical surface portion of the elastic body seal, the fluid may enter the back surface side of the elastic body seal from this portion. For this reason, a portion of the elastic seal that is separated from the spherical surface portion is deformed by fluid that has entered the back side of the elastic seal, or an auxiliary member (backup ring) installed on the back side of the elastic seal protrudes. As a result, the elastic seal becomes unstable. As described above, when the elastic seal becomes unstable, the sealing performance of the ball valve is deteriorated, so that it is necessary to replace the elastic seal.

  Therefore, in Patent Document 1 described above, a protrusion is formed on the outer peripheral portion of the elastic seal, and the protrusion is engaged with a seal groove formed in the valve body. However, this protrusion is for holding and holding the elastic seal against the seal groove only by a physical locking force, and does not prevent fluid from entering the back side of the elastic seal. There wasn't. Therefore, if a force greater than the locking force of the protrusion is applied to the elastic body seal by the fluid that has entered the back surface, the protrusion cannot be withstood and the locked state is forcibly released. No longer works. This is particularly likely to occur when fluid is passed through the ball valve at a high flow rate.

  Accordingly, the main object of the present invention is to solve the above-described problems.

In order to solve the above problems, the present invention provides:
A valve body having a flow path section through which a fluid flows and a valve body accommodating space provided in the middle of the flow path section;
A ball-shaped valve element installed inside the valve element accommodating space and rotated by an operation unit;
A communication hole formed in the ball-shaped valve body and capable of communicating between the flow path portions on both sides of the valve body accommodating space;
In a ball valve having an elastic seal that is installed at a boundary portion between the valve body accommodating space and the flow path portion and pressed against the spherical surface portion of the ball-shaped valve body,
The elastic body seal is provided with an intrusion prevention portion capable of preventing the intrusion of fluid to the back surface side.

  According to the present invention, it is possible to prevent the intrusion of fluid into the back surface side of the elastic seal by the above-described intrusion prevention unit. Thereby, it becomes possible to always keep the elastic body seal in a stable state.

It is a longitudinal cross-sectional view of the open state of the ball valve concerning this Embodiment. It is a longitudinal cross-sectional view of the closed state of the ball valve of FIG. It is a partial cross-sectional view which shows the state of the ball valve body in the middle of opening and closing. It is an enlarged view of the elastic body seal part of FIG. FIG. 5 is an enlarged view of an elastic seal portion similar to FIG. 4, showing a state where no intrusion prevention unit is provided.

Hereinafter, the present embodiment will be described in detail with reference to the drawings.
1 to 5 are for explaining this embodiment.

<Configuration> The configuration will be described below.
1 and 2, a ball valve 1 according to this embodiment includes a flow path portion 3 and 4 through which a fluid 2 flows and a valve provided in the middle of the flow path portions 3 and 4. A valve body 6 having a body accommodating space 5;
A ball-shaped valve body 8 installed inside the valve body housing space 5 and rotated by the operation unit 7;
A communication hole 9 formed in the ball-shaped valve body 8 and capable of communicating between the flow path portions 3 and 4 on both sides of the valve body housing space 5;
And elastic body seals 13 and 14 which are installed at a boundary portion between the valve body accommodating space 5 and the flow path portions 3 and 4 and are pressed against the spherical surface portion 11 of the ball-shaped valve body 8. Is done.

  Here, the fluid 2 can be, for example, a liquid such as water or a gas. The flow path portions 3 and 4 are holes having a circular cross section formed in the valve body 6. In this case, the flow path portions 3 and 4 extend in a straight line in the diameter direction of the ball-shaped valve body 8. The valve body accommodating space 5 is a space in which the ball-shaped valve body 8 is inserted. The flow path portions 3 and 4 are divided into a primary side (entry side) flow path portion 3 and a secondary side (exit side) flow path portion 4 by the valve body accommodating space 5.

  The valve body 6 constitutes the body of the ball valve 1. In the valve body 6, an opening 15 larger than the diameter of the ball-shaped valve body 8 is formed on one end side so that the ball-shaped valve body 8 can be inserted and installed in the valve body housing space 5. A cylindrical ball holding member 16 having one flow path portion 3 is attached to the opening 15. A screw fixing portion 17 is formed between the inner peripheral surface of the opening 15 and the outer peripheral surface of the ball holding member 16 so as to be detachably screwed together. With this structure, one flow path portion 3 is indirectly provided inside the valve body 6 via the ball holding member 16. In addition, in order to enable the ball-shaped valve body 8 to be inserted and installed in the valve body accommodating space 5, there are also those in which the valve body 6 is directly divided vertically. In this case, the split pieces of the vertically divided valve body 6 are fastened and fixed together with screws or the like with a gasket interposed therebetween.

  Further, at both ends of the valve body 6, pipe fixing portions 18 for fixing to the pipe where the ball valve 1 is installed are provided. In this case, the pipe fixing portion 18 is configured such that a union nut 21 that can be screwed to the outer peripheral surface of the flow path portions 3 and 4 is attached to the receiving member 19 that can insert and fix the pipe. The union nut 21 is rotatably locked to a flange portion provided in the receiving member 19. In addition, there is a pipe fixing portion 18 as an attachment flange.

  The operating portion 7 is formed by penetrating a stem 22 (an operating shaft or a rotation center axis) attached so as to extend upward with respect to the upper portion of the ball-shaped valve body 8 in the figure, and passing through the valve body 6 of the stem 22. And a handle 23 (gripping part) attached to the protruding part.

  The ball-shaped valve body 8 has a substantially spherical shape having a spherical surface portion 11 on at least a part of the outer surface, and the communication hole 9 is formed so as to penetrate in the diameter direction perpendicular to the stem 22, and the flow path portion 3. , 4 can communicate with each other. The communication hole 9 has the same diameter as the flow path portions 3 and 4.

  The boundary portion is a corner portion of a step portion formed between the flow path portions 3 and 4 and the valve body accommodating space 5 in the valve body 6 or the ball holding member 16. The spherical portion 11 is formed at least with respect to a portion (other than the communication hole 9) that comes into contact with the elastic seals 13 and 14 when the ball-shaped valve body 8 is rotated about the stem 22.

  The elastic body seals 13 and 14 are annular ones extending along the circumferential direction of the flow path portions 3 and 4. On the surface side of the elastic body seals 13 and 14, a pressure contact surface portion 12 (water blocking surface) that is pressed against the spherical surface portion 11 of the ball-shaped valve body 8 is formed (see FIG. 4). The elastic body seals 13 and 14 are made of, for example, polytetrafluoroethylene (generic name: PTFE), ethylene propylene rubber (generic name: EPDM), fluorine rubber (generic name: FKM), nitrile rubber (generic name: NBR), or the like. Composed. The primary elastic seal 13 is called a primary sheet (ball sheet) or the like. The secondary-side elastic seal 14 is called a secondary sheet (integral sheet) or the like.

  A backup ring 25 (see FIG. 3) for supporting the elastic seals 13 and 14 from the back side is installed on the back side of the elastic seals 13 and 14 in the valve main body 6 and the ball holding member 16.

  Besides, between the inner peripheral surface of the opening 15 of the valve main body 6 and the outer peripheral surface of the ball holding member 16, the end surface of the valve main body 6, and the receiving member 19 constituting the pipe fixing portion 18 with respect to the valve main body 6. Seal members 26 to 29 are provided between the contact surface and between the valve body 6 and the stem 22.

In contrast to the basic configuration as described above, this embodiment has the following configuration.
(1) As shown in FIG. 4, the elastic body seal 13 is provided with an intrusion prevention portion 31 that can prevent the fluid 2 from entering the back surface (of the elastic body seal 13).

  Here, the intrusion prevention unit 31 may be any member as long as it can prevent the fluid 2 from entering the back side (of the pressure contact surface portion 12 of the elastic seal 13).

  In this case, the intrusion prevention unit 31 is provided in the portion of the elastic body seal 13 on the flow path portion 3 side, but the portion of the elastic body seal 13 on the valve body accommodating space 5 side or the flow path of the elastic body seal 14 is provided. It can also be provided for the portion on the side of the portion 4 and the portion of the elastic seal 14 on the side of the valve body accommodating space 5.

(2) More specifically, the elastic body seal 13 is fitted and installed in a seal fitting recess 35 provided in the boundary portion.
The intrusion prevention part 31 is formed so as to extend from the surface of the elastic seal 13 so as to cover the gap 36 between the seal fitting recess 35 and the elastic seal 13. It is said.

  Here, the seal fitting recess 35 (seal groove) is formed by cutting out the above-described boundary portion (a stepped corner portion formed between the flow path portion 3 and the valve body accommodating space 5) into an L shape. The elastic body seal 13 has a substantially triangular cross section that matches the seal fitting recess 35. The same applies to the elastic seal 14.

  In this case, the surface of the elastic body seal 13 is an edge on the flow path portion 3 side. The gap 36 is a slight gap formed between the seal fitting recess 35 and the elastic seal 13. The cover part 37 is a cover for covering the gap 36. The cover part 37 extends along the inner peripheral surface of the flow path part 3 so as to be separated from the seal fitting recess 35.

(3) The cover portion 37 is formed as a tapered protruding portion 41 that becomes thinner from the base side toward the distal end side.
Then, a tapered notch 42 that accommodates and holds the tapered protrusion 41 in a flush state with the flow path portion 3 is formed at the edge of the seal fitting recess 35.

  Here, the base side is a portion close to the elastic body seal 13 and the seal fitting recess 35. Further, the distal end side is a portion away from the elastic seal 13 and the seal fitting recess 35. In this case, the tapered protrusion 41 has a triangular cross section. The tapered cutout 42 has an inclined shape with which the tapered protrusion 41 matches.

<Operation> The operation of this embodiment will be described below.
The above-described ball valve 1 operates the handle 23 to rotate the ball-shaped valve body 8 around the stem 22 and flows through the communication hole 9 formed in the ball-shaped valve body 8 as shown in FIG. By communicating with the passage portions 3 and 4, the ball valve 1 is opened, and the fluid 2 can flow. Further, by operating the handle 23, the ball-shaped valve body 8 is rotated in the direction opposite to the above with the stem 22 as a center, and the communication hole 9 formed in the ball-shaped valve body 8 is formed as shown in FIG. By not communicating with the flow path portions 3 and 4, the ball valve 1 is closed and the flow of the fluid 2 can be stopped.

  At this time, the elastic seals 13 and 14 installed at the boundary portion between the valve body accommodating space 5 and the flow path portions 3 and 4 are brought into pressure contact with the pressure contact surface portion 12 of the ball-shaped valve body 8. , Leakage of fluid 2 can be sealed.

<Effect> According to this embodiment, the following effects can be obtained.
(1) As shown in FIG. 4, an intrusion prevention unit 31 is provided in the elastic seal 13. The intrusion prevention unit 31 prevents the fluid 2 from entering the back side of the elastic seal 13. Therefore, during the turning operation of the ball-shaped valve body 8, the opening of the communication hole 9 crosses the elastic body seal 13 as shown in FIG. However, the fluid 2 does not enter the back side of the elastic seal 13 from the portion that does not contact the ball-like valve body 8 of the elastic seal 13. Therefore, the deformation of the elastic seal 13 or the backup ring 25 installed on the back side of the elastic seal 13 caused by the fluid 2 entering the back side of the elastic seal 13 as shown in FIG. And the like, and the elastic body seal 13 can always be kept in a stable shape and state. As described above, when the elastic seal 13 is stabilized, the sealing performance of the ball valve 1 is maintained for a long period of time, so that the maintenance work of the ball valve 1 can be reduced. Such an intrusion prevention unit 31 is particularly effective for the ball valve 1 that is used for the purpose of flowing the fluid 2 at a high speed.

  (2) As the intrusion prevention unit 31, the cover 37 extending from the surface of the elastic seal 13 is integrally provided on the elastic seal 13. The cover portion 37 directly covers the inlet portion of the gap 36 between the seal fitting recess 35 and the elastic seal 13. Therefore, it is possible to reliably prevent the fluid 2 from entering the inside of the seal fitting recess 35 from the gap 36 described above.

  (3) The cover part 37 is a tapered protrusion 41. A tapered notch 42 was formed at the edge of the seal fitting recess 35. Thereby, the taper-shaped protrusion 41 and the notch 42 are closely contacted with each other by the taper-shaped protrusion 41 being aligned with the taper-shaped notch 42, so that the taper-shaped protrusion 41 is the flow path portion 3. It will be in a state of being flush with the inner peripheral surface. As a result, it is suppressed that the tapered protrusion 41 disturbs the flow of the fluid 2. In addition, since the adhesiveness between the tapered protrusion 41 and the notch 42 is enhanced by applying the pressure of the fluid 2 to the tapered protrusion 41, the fluid 2 can be more effectively penetrated into the gap 36. It becomes possible to prevent. Further, by making the base side of the taper-shaped protrusion 41 thicker than the tip end side, the taper-shaped protrusion 41 can be hardly turned up by the fluid 2.

  As mentioned above, although embodiment of this invention has been explained in full detail with drawing, embodiment is only an illustration of this invention. Therefore, the present invention is not limited only to the configuration of the embodiment, and it goes without saying that design changes and the like within a scope not departing from the gist of the present invention are included in the present invention. Further, for example, when each embodiment includes a plurality of configurations, it is a matter of course that possible combinations of these configurations are included even if not specifically described. In addition, in the case where a plurality of examples and modifications are disclosed in the embodiment as those of the present invention, possible combinations of combinations extending over these are included even if not specifically described. Of course. Further, the configuration depicted in the drawings is of course included even if not particularly described. Further, when there is a term of “etc.”, it is used in the sense that the equivalent is included. In addition, when there are terms such as “almost”, “about”, “degree”, etc., they are used in the sense that they include those in the range and accuracy recognized by common sense.

DESCRIPTION OF SYMBOLS 1 Ball valve 2 Fluid 3 Flow path part 4 Flow path part 5 Valve body accommodation space 6 Valve main body 7 Operation part 8 Ball-shaped valve body 9 Communication hole 11 Spherical surface part 13 Elastic body seal 14 Elastic body seal 31 Intrusion prevention part 35 Seal fitting Combined recess 36 Clearance 37 Cover part 41 Tapered protrusion 42 Tapered notch

Claims (3)

A valve body having a flow path section through which a fluid flows and a valve body accommodating space provided in the middle of the flow path section;
A ball-shaped valve element installed inside the valve element accommodating space and rotated by an operation unit;
A communication hole formed in the ball-shaped valve body and capable of communicating between the flow path portions on both sides of the valve body accommodating space;
In a ball valve having an elastic seal that is installed at a boundary portion between the valve body accommodating space and the flow path portion and pressed against the spherical surface portion of the ball-shaped valve body,
A ball valve characterized in that an intrusion prevention portion capable of preventing intrusion of fluid into the back side is provided on the elastic body seal. The ball valve according to claim 1,
The elastic body seal is fitted and installed in a seal fitting recess provided in the boundary portion,
The intrusion prevention portion is a cover portion that is formed so as to extend continuously from the surface of the elastic seal, and covers a gap between the seal fitting recess and the elastic seal. valve. The ball valve according to claim 2,
The cover portion is a taper-shaped protruding portion that becomes thinner from the base side toward the tip side,
The ball valve according to claim 1, wherein a tapered notch is formed at an edge of the seal fitting recess to accommodate and hold the tapered protrusion in a flush state with the flow path.