JP2016217465A - Butterfly valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a butterfly valve in which the structure of a valve seat is simple, a valve element of an eccentric butterfly valve and a valve element of a center type butterfly valve can be replaced, and a valve casing and the valve seat can be standardized.SOLUTION: A butterfly valve 1 comprises a valve casing 2 with a valve seat 5 provided on the inner peripheral surface of a flow channel 4, and a valve element 30 which opens and closes the flow channel 4 by rotation of a valve rod 6. The valve seat 5 is extended from a seal position of a central valve element where it stops fluid at least at the axis O2 position of the valve rod 6, to a seal position of an eccentric valve element 3 where it stops fluid at an eccentric position shifted from the axis O2 of the valve rod 6, so that the central valve element and the eccentric valve element 3 can be replaced with each other in the same valve casing 2. For the eccentric valve element 3, a rotation center displacement mechanism 7 is equipped for gradually displacing the rotation center X of the eccentric valve element 3 during opening and closing operation of the flow channel 4.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a butterfly valve.

  As the butterfly valve, as shown in Patent Document 1, a so-called center-type butterfly valve in which the axial center position of the valve stem, that is, the rotation center position of the valve body and the seal position coincide with the flow path direction; As shown in FIG. 2, there is a so-called eccentric butterfly valve in which the rotation center position of the valve body and the seal position are shifted in the flow path direction. An eccentric butterfly valve has the advantage that it is less susceptible to fluid pressure when opening and closing the valve.

  The eccentric butterfly valve has a large rotation diameter because the rotation center position of the valve body and the seal position are shifted in the flow path direction. For this reason, the valve body is made smaller than the inner diameter of the valve box, and the valve seat has a shape protruding inside the valve box.

JP-A-8-145196 Japanese Patent Application No. 2010-223919

  As described above, the eccentric butterfly valve has a problem in that the valve seat needs to be arranged to project radially inward from the inner peripheral surface of the flow path of the valve box, and the structure of the valve seat becomes complicated. Furthermore, since the position of the valve seat differs between the central butterfly valve and the eccentric butterfly valve, there is a problem that the same valve box valve seat cannot be used.

  The present invention has been created to solve such problems. The structure of the valve seat is simple, and the valve body of the eccentric butterfly valve and the valve body of the central butterfly valve can be exchanged. It is an object to provide a butterfly valve that can be used in common.

In order to solve the above problems, the present invention provides a butterfly valve comprising a valve box having a valve seat on the inner peripheral surface of a flow path, and a valve body that opens and closes the flow path by rotation of a valve rod. The seat extends from at least the seal position of the central valve body that stops water at the axial center position of the valve stem to the seal position of the eccentric valve body that stops water at an offset position that deviates from the axial center of the valve stem, The central valve body and the eccentric valve body are configured to be exchangeable in the same valve box, and the eccentric valve body includes a rotation center displacement mechanism that gradually displaces the rotation center of the eccentric valve body during opening and closing operations. It is characterized by.
The “eccentric valve body” means a valve body in which the rotation center position and the seal position of the valve body are shifted in the flow path direction. The “central valve body” means a valve body in which the rotation center position and the seal position of the valve body coincide with the flow path direction.

  According to the present invention, since the valve seat extends at least from the sealing position of the central valve body to the sealing position of the eccentric valve body, the central valve body and the eccentric valve body can be exchanged in the same valve box even if they are replaced. It is possible to stop the valve body and the eccentric valve body. Further, since the eccentric valve element is provided with the rotation center displacement mechanism, the rotation center of the valve element can be gradually displaced, and the opening / closing operation of the eccentric valve element can be performed.

  Further, in the present invention, the rotation center displacement mechanism is configured to gradually adjust the rotation center of the eccentric valve body by a reaction force that the eccentric valve body receives from the valve seat during the opening / closing operation of the eccentric valve body immediately before the fully closed state. A locking portion projecting on the outer periphery of the valve stem so as to be displaced and formed on the eccentric valve body, the eccentric valve body being slidable with respect to the valve rod, and locking with the locking portion And a slide hole capable of rotating the eccentric valve body with respect to the valve stem.

  According to the present invention, the rotational center of the eccentric valve body can be gradually displaced by the reaction force received by the eccentric valve body from the valve seat and the slide hole, and the rotational center displacement mechanism can be made simple.

  Further, according to the present invention, the locking portion protrudes as a pair at positions opposite to each other by 180 degrees across the valve shaft axis, and the slide hole includes a valve rod housing hole portion for housing the valve rod. And a pair of locking holes for locking with the locking portion.

  According to the present invention, since the rotational force transmission portion is provided at two positions across the shaft center, transmission loss of rotational force from the valve stem to the eccentric valve body can be reduced.

  According to the present invention, the structure of the valve seat is simple, and the valve body of the eccentric butterfly valve and the valve body of the central butterfly valve can be exchanged. Therefore, since the valve box can be shared, the number of parts can be reduced and the manufacturing cost can be reduced. In addition, it is possible to cope with fluids to be used and specification changes by simply replacing the valve body.

It is a plane sectional view of the butterfly valve of the present invention. It is a sectional side view of the butterfly valve of the present invention. It is a sectional side view of the butterfly valve of the present invention. It is explanatory drawing of the locus | trajectory of a rotation center. It is a sectional side view of the butterfly valve from which the axial center and the diameter center of a valve stem have shifted. It is a sectional side view of the butterfly valve which attached the central valve body instead of the eccentric valve body.

1, 2, and 6, the butterfly valve 1 includes a valve box 2 in which a valve seat 5 is provided on the inner peripheral surface of the flow path 4, and a valve body 30 that opens and closes the flow path 4 by the rotation of the valve rod 6. And.
The valve seat 5 stops water at an offset position deviated from the shaft center of the valve stem 6 from the seal position of the valve body 30 (which is referred to as the central valve body 14) that stops at least at the shaft center position of the valve stem 6. The valve body 30 (which is referred to as an eccentric valve body 3) is extended to a sealing position, and the central valve body 14 and the eccentric valve body 3 can be exchanged in the same valve box 2.
The eccentric valve body 3 includes a rotation center displacement mechanism 7 that gradually displaces the rotation center of the eccentric valve body 3 when the flow path 4 is opened and closed.

  As shown in FIGS. 1 and 2, a flow path 4 having a circular section having a diameter center O1 is formed inside the valve box 2. A cylindrical valve seat 5 is provided on the inner peripheral surface of the valve box 2 forming the flow path 4. The valve seat 5 is made of, for example, hard rubber. A valve rod 6 is attached to the valve box 2 to rotate around an axis O2 orthogonal to the flow path 4 by a drive source (not shown). The position of the axis O2, that is, the rotation center position of the eccentric valve body 3, and the seal position between the eccentric valve body 3 and the valve seat 5 are shifted by a distance L in the flow path direction. The eccentric valve body 3 has a disk shape, and an edge portion 21 that is in close contact with the valve seat 5 is fixed to the outer periphery by welding or the like.

  In FIG. 2, the butterfly valve 1 rotates to gradually displace the rotation center X of the eccentric valve body 3 by the reaction force received by the eccentric valve body 3 from the valve seat 5 during the opening / closing operation of the eccentric valve body 3 immediately before the fully closed state. A center displacement mechanism 7 is provided. The eccentric valve body 3 rotates in the counterclockwise direction (Q direction) around the rotation center X from the fully closed state shown in FIG. The rotation center displacement mechanism 7 of the present embodiment is formed in a locking portion 8 projecting from the outer periphery of the valve stem 6 and a support portion 9 of the eccentric valve body 3, and the eccentric valve body 3 is connected to the valve stem 6. The slide hole 10 is configured to be slidable and locked with the locking portion 8 and capable of rotating the eccentric valve body 3 with respect to the valve stem 6. As shown in FIG. 1, the support portions 9 are attached to one surface of the eccentric valve body 3 as a pair with an interval in the extending direction of the valve stem 6.

  In FIG. 2, the locking portions 8 are provided as a pair on the outer periphery of the valve stem 6 at a position 180 degrees opposite to each other with the axis O <b> 2 interposed therebetween. The locking portion 8 has a substantially rectangular shape when viewed from the direction of the axis O2. As can be seen from FIG. 1, the locking portion 8 protrudes from the outer periphery of the valve stem 6 located in the slide hole 10. As shown in FIG. 2, the protruding direction of the locking portion 8 is parallel to the extending direction of the eccentric valve body 3.

  The slide hole 10 includes a valve rod housing hole portion 11 that houses the valve rod 6 and a pair of locking hole portions 12 that lock the locking portion 8. The valve stem housing hole 11 is a circular hole having a larger diameter than the valve stem 6. The locking hole portion 12 is a rectangular hole formed continuously with the valve rod housing hole portion 11 so that the locking portion 8 can slide relative to the extending direction of the eccentric valve body 3 therein. It has become.

  The butterfly valve 1 having the above configuration can be replaced with a central valve body 14 having a common axis O2, as shown in FIG. The central valve body 14 rotates integrally with the valve stem 6. As described above, the valve seat 5 is composed of a cylindrical member having a length corresponding to at least both the sealing position of the eccentric valve body 3 and the sealing position of the central valve body 14.

"Action"
With reference to FIG. 3, the effect | action of the butterfly valve 1 at the time of providing the eccentric valve body 3 is demonstrated. FIG. 3A shows a state in which the eccentric valve body 3 is fully closed. The rotational center X of the eccentric valve body 3 at this time coincides with the axis O2 of the valve stem 6. The valve stem 6 is positioned concentrically in the valve stem receiving hole 11, and a relief space 13 </ b> A is formed around the valve stem 6. In addition, an escape space 13B is formed in one of the locking holes 12.

  When the valve stem 6 is rotated in the Q direction as shown in FIG. 3B by a drive source (not shown), the upper end 3A side of the eccentric valve body 3 in FIG. It slides with the locking portion 8 while sliding. That is, during the opening operation of the eccentric valve body 3 immediately before the fully closed state, the rotation center X of the eccentric valve body 3 is gradually displaced from the position of the axis O2. From the state of FIG. 3A to the state of FIG. 3B, the upper end 3A side moves linearly along the flow path 4, and the lower end 3B side moves along an arcuate locus. When the predetermined sliding operation of the locking hole portion 12 and the locking portion 8 ends, the locking hole portion 12 rotates with the locking portion 8 as it is, and the eccentric valve body 3 flows as shown in FIG. It becomes parallel with the path 4 and is fully opened. Even when the eccentric valve body 3 is closed, the locking hole 12 is locked by the reaction force received by the upper end 3A side of the eccentric valve body 3 from the valve seat 5 in the process from FIG. 3 (b) to FIG. 3 (a). It will slide with respect to the part 8.

  FIG. 4 is an enlarged view of the locus of the rotation center X. Symbols P1, P2, and P3 indicate that the valve stem 6 is in the state of FIGS. 3 (a), 3 (b), and 3 (c), respectively. Assuming an orthogonal coordinate system of the x axis parallel to the flow path 4 and the y axis orthogonal to the flow path 4 with the axis O2 as the origin, the quadrant where the upper end 3A of the eccentric valve body 3 in the fully closed state is located is If one quadrant is set and the second quadrant, the third quadrant, and the fourth quadrant are counterclockwise from there, the trajectories S1 and S2 of the rotation center X are positioned in the fourth quadrant where the lower end 3B is located. The trajectory S1 indicates a trajectory from the position of the locking hole 12 to the position P2 from the position P1, and the trajectory S2 indicates a trajectory from the position of the locking hole 12 to the position P3 from the position P2. . The locus S1 is a locus in which the rotation center X gradually moves away from the axis O2 toward the lower end 3B when the eccentric valve body 3 is opened.

  As described above, the present invention is a butterfly including the valve box 2 in which the valve seat 5 is provided on the inner peripheral surface of the flow path 4 and the valve body 30 that opens and closes the flow path 4 by the rotation of the valve rod 6. In the valve 1, an eccentric valve body that stops water at an eccentric position that deviates from the axial center O2 of the valve stem 6 from the seal position of the central valve body 14 that stops water at least at the axial center O2 position of the valve stem 6. The central valve element 14 and the eccentric valve element 3 can be exchanged with the same valve box 2. The eccentric valve body 3 is provided with a rotation center displacement mechanism 7 that gradually displaces the rotation center X of the eccentric valve body 3 when the flow path 4 is opened and closed. According to this, since the valve box 2 can be shared, the number of parts can be reduced and the manufacturing cost can be reduced. Moreover, it is possible to cope with a fluid to be used and a specification change by simply replacing the valve body 30.

  The valve seat 5 may be a simple cylindrical member having a length corresponding to both the sealing position of the eccentric valve body 3 and the sealing position of the central valve body 14. Therefore, the attachment structure of the valve seat 5 to the valve box 2 is also simplified.

  Further, as the rotation center displacement mechanism 7, the rotation center X of the eccentric valve element 3 is gradually displaced by the reaction force received by the eccentric valve element 3 from the valve seat 5 during the opening / closing operation of the eccentric valve element 3 immediately before the fully closed state. Further, a locking portion 8 projecting from the outer periphery of the valve stem 6 and the eccentric valve body 3 are formed, and the eccentric valve body 3 can be slid with respect to the valve rod 6 and locked with the locking portion 8. If the configuration includes the slide hole 10 that can rotate the eccentric valve body 3 with respect to the rod 6, the rotation of the eccentric valve body 3 by the reaction force that the eccentric valve body 3 receives from the valve seat 5 and the slide hole 10. The center X can be gradually displaced, and the rotation center displacement mechanism 7 can have a simple structure.

  In addition, the locking portion 8 protrudes as a pair at a position 180 degrees opposite to the shaft center O2 of the valve stem 6, and the slide hole 10 is engaged with the valve rod receiving hole portion 11 for receiving the valve rod 6, and the engagement. If the stop portion 8 and the pair of locking hole portions 12 are configured, the rotational force transmitting portion is provided at two positions with the shaft center O2 interposed therebetween, so that the valve stem 6 to the eccentric valve body 3 is provided. The transmission loss of the rotational force can be reduced.

  The preferred embodiment of the present invention has been described above. As shown in FIG. 5, the present invention can be implemented even when the axial center O2 of the valve stem 6 and the diameter center O1 are displaced in the flow path width direction (indicated by the symbol W).

DESCRIPTION OF SYMBOLS 1 Butterfly valve 2 Valve box 3 Eccentric valve body 4 Flow path 5 Valve seat 6 Valve rod 7 Rotation center displacement mechanism 8 Locking part 10 Slide valve 14 Central valve body 30 Valve body O1 Diameter center O2 (Valve shaft) shaft center

Claims (3)

In a butterfly valve consisting of a valve box provided with a valve seat on the inner peripheral surface of the flow path, and a valve body that opens and closes the flow path by rotation of the valve rod,
The valve seat extends from at least a seal position of a central valve body that stops water at an axial center position of the valve stem to a seal position of an eccentric valve body that stops water at an offset position deviated from the axial center of the valve stem. The central valve body and the eccentric valve body are configured to be replaceable in the same valve box,
The eccentric valve body includes a rotation center displacement mechanism that gradually displaces the rotation center of the eccentric valve body during opening and closing operations. The rotation center displacement mechanism is configured to gradually displace the rotation center of the eccentric valve body by a reaction force that the eccentric valve body receives from the valve seat during the opening and closing operation of the eccentric valve body immediately before the fully closed state.
A locking portion protruding from the outer periphery of the valve stem;
A slide hole formed in the eccentric valve body, capable of sliding the eccentric valve body with respect to the valve stem, and capable of being engaged with the locking portion and rotating the eccentric valve body with respect to the valve stem;
The butterfly valve according to claim 1, comprising: The locking portions protrude as a pair at positions opposite to each other by 180 degrees across the axis of the valve stem,
3. The butterfly according to claim 2, wherein the slide hole includes a valve rod housing hole portion that houses the valve rod, and a pair of locking hole portions that are locked to the locking portion. valve.

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