JP6472201B2 - Seat ring and butterfly valve for butterfly valve - Google Patents

Description

  The present invention relates to a seat ring for a butterfly valve suitably used for piping lines in various industries such as a chemical factory, water and sewage, agriculture / fisheries, semiconductor manufacturing field, food field, and the like, and a butterfly valve using the same. .

  The butterfly valve includes a valve body having an internal flow path, a seat ring mounted on an inner peripheral surface of the internal flow path of the valve body, a valve shaft extending through the seat ring and supported by the valve body, and a valve And a valve body fixedly attached to the valve shaft so as to rotate together with the valve shaft, the valve body using the valve shaft. The valve body is rotated inside and the valve body is opened and closed by pressing and separating the outer peripheral surface of the valve body against the inner peripheral surface of the seat ring.

  The valve body is provided with a pair of valve shaft support holes for supporting the valve shaft at opposite positions in the radial direction of the internal flow path, at least one of which extends through the valve body. The seat ring includes a cylindrical main body portion and flange portions provided at both ends of the central axis of the main body portion. The seat ring is fitted around the openings at both ends of the internal flow path of the valve main body. The seat ring is mounted on the valve body by fitting the flange portion of the seat ring into the mating recess. A pair of valve shaft holes for penetrating the valve shaft are formed in the body portion of the seat ring so as to face each other in the radial direction.

  In such a butterfly valve, the inner peripheral diameter of the main body of the seat ring is slightly smaller than the outer peripheral diameter of the valve body, and the outer peripheral surface of the valve body is pressed against the main body of the seat ring when the valve is closed. Seal. However, in the area around the valve shaft hole of the main part of the seat ring, there is a drawback that the effective surface pressure is low, and if the compression ratio of the main part of the seat ring is the same, the sealing effect is small and leakage is likely to occur. For this reason, like the butterfly type shut-off valve described in Patent Document 1, for example, the thickness of the peripheral region of the valve shaft hole of the main body is continuously increased to reach the final thickness in the region of the valve shaft hole. It is proposed to improve the sealing effect by increasing the compression rate when the seat ring is closed in the vicinity of the valve shaft hole.

JP 7-501606

  As described above, in the butterfly valve, sealing is performed by pressing the outer peripheral surface of the valve body against the inner peripheral surface of the seat ring mounted on the internal flow path. It is common to form. Further, when a butterfly valve is used for piping that handles a corrosive fluid, the corrosive fluid comes into contact with the seat ring, so that sufficient corrosion resistance is required, but it is difficult to satisfy this with an elastomer material. For this reason, in a butterfly valve used for a pipe that handles a corrosive fluid, a covering made of a resin material is often used inside the seat ring.

  However, as described above, in the butterfly valve in which the covering made of a resin material is mounted on the inner side of the seat ring, in order to prevent leakage in the vicinity of the valve shaft hole, as in the butterfly valve described in Patent Document 1, When the thickness of the surrounding region of the valve shaft hole of the main body is increased, the portion of the seat ring having increased thickness (hereinafter referred to as “compressed portion”) is lifted from the covering when the valve is closed, The pressing force due to the compression acts on the valve body unevenly, the sealing performance in the vicinity of the valve shaft hole becomes insufficient, and leakage tends to occur.

  In order to solve the above-described problems of the prior art, an object of the present invention is to prevent leakage by improving sealing performance in the vicinity of a valve shaft hole in a seat ring for a butterfly valve having chemical resistance. And

In view of the above-mentioned object, the present invention provides, as a first aspect, a valve body of a butterfly valve that is mounted on an inner peripheral surface of an internal flow path extending along a flow path axis, and is pivotable in the internal flow path. A pair of seat rings for a butterfly valve that abuts on the outer peripheral surface of a supported valve body, having a substantially cylindrical peripheral wall, and extending through the valve shaft hole axis at opposite positions of the peripheral wall A body portion made of an elastomer material in which a valve shaft hole is formed, and a covering body made of a resin material provided so as to cover the inner peripheral surface of the main body portion and the inner peripheral surfaces of the pair of valve shaft holes; , the outer peripheral surface of the main body portion, and a ridge formed around each of said pair of valve shaft hole is integrally formed with said body portion and said cover body are joined, the The raised portion is raised at a certain height with respect to the outer peripheral surface of the main body, and the peripheral portion of the main body is A curved section extending in a curved line, and a planar connection section extending between each of both ends in the circumferential direction of the outer circumferential surface of the curved section and a merging portion on the outer circumferential surface of the main body section, and the connection The length L1 of the portion of the curved section extending in the circumferential direction of the valve shaft hole when the section extends in the tangential direction at the junction and projected onto a plane perpendicular to the valve shaft hole axis is the valve shaft hole. There is provided a seat ring for a butterfly valve that is shorter than the length L2 of the connection section when projected onto a plane perpendicular to the axis .

  In the seat ring for a butterfly valve, the inner peripheral surface of the main body portion formed of an elastic elastomer material and the inner peripheral surface of the pair of valve shaft holes are covered with a covering made of a resin material. Sometimes, the cover is pressed against the outer peripheral surface of the valve body and the valve shaft by the main body portion and closely adheres to exhibit high sealing performance. Moreover, since the part which the fluid which flows through the inside flow path can contact is coat | covered with the coating body made from a resin material, chemical resistance is improved. Furthermore, in the conventional butterfly valve, when the outer peripheral surface of the valve body is pressed against the inner peripheral surface of the seat ring main body for sealing, the effective surface pressure near the valve shaft hole is reduced. There was a problem that leakage was likely to occur. On the other hand, in the seat ring for the butterfly valve, a raised portion is formed around the valve shaft hole on the outer peripheral surface of the main body, and the thickness of the elastomer material layer around the valve shaft hole is increased. Therefore, a higher pressing force near the valve shaft hole than the remaining part acts on the outer peripheral surface of the valve body and the valve shaft against the cover, and the effective surface pressure near the valve shaft hole when the valve is closed is reduced. increase. As a result, while suppressing an increase in operating torque, the sealing performance in the vicinity of the valve shaft hole and its durability are improved, and leakage can be suppressed. In addition, if the main body and the cover are provided separately, the cover is lifted from the main body near the boundary of the raised portion when the valve is closed, creating a gap, and the pressure applied to the valve body by the raised portion is reduced. There is a risk that it becomes non-uniform and sufficient sealing performance cannot be obtained. However, in the seat ring for the butterfly valve, since the main body and the cover are integrally formed, the cover is prevented from floating from the main body, and the sealing performance is surely improved. it can.

Furthermore, since the curved section of the raised portion and the outer peripheral surface of the main body portion are connected by the connecting section, the pressing force from the raised portion to the portion where the raised portion is not provided is smoothly changed. Thus, a sudden change in the pressing force can be avoided, a more uniform sealing performance can be exhibited over the entire outer peripheral surface of the valve body, and leakage to the secondary side can be prevented.

Also, connections when the length L1 of the Curved segment portion of Ru circumferentially extending sides of the valve shaft hole when projected onto a plane perpendicular to the valve shaft hole axis is projected on a plane perpendicular to the valve shaft hole axis more short this than the length L2 of the segment, gently changing the pressing force to the valve body from the curved section of the raised portion to the portion where the raised portion is not provided, to avoid sudden changes in the pressing force In the entire peripheral surface of the valve body, more uniform sealing performance can be exhibited and leakage to the secondary side can be prevented.

  The main body and the covering can be joined by, for example, vulcanization adhesion.

It is preferable that the seat ring further includes a flange portion at both ends of the main body portion in the flow path axis direction, and the raised portion is provided apart from the flange portion.
Moreover, the some groove | channel extended in the circumferential direction may be formed in the outer peripheral surface of the said main-body part.
Furthermore, it is preferable that the covering is formed of a fluororesin material.

  The present invention provides, as a second aspect, a valve body having an internal flow path extending along a flow path axis inside, the seat ring mounted on the inner peripheral surface of the internal flow path, and the seat ring A valve shaft extending through the valve shaft hole; and a valve body rotatably supported by the valve body by the valve shaft, wherein the valve body is rotated in the valve body to rotate the valve body. A butterfly valve that opens and closes is provided by pressing and separating the outer peripheral surface of the cover from the inner peripheral surface of the covering of the seat ring.

  In the said butterfly valve, it is preferable that the outer peripheral surface of the said valve body contact | abutted with the internal peripheral surface of the said cover body is formed in spherical shape. As a result, it is possible to reduce the resistance that acts when the valve element is rotated due to the opening and closing of the butterfly valve, reduce the required operating torque, and improve the durability.

  It is preferable that the valve body has a spherical contact surface that contacts a peripheral region of the valve shaft hole on the inner peripheral surface of the seat ring.

  According to the seat ring for a butterfly valve and the butterfly valve using the same according to the present invention, the chemical resistance is improved by covering the inner peripheral surface of the main body and the inner peripheral surface of the valve shaft hole with a covering. In addition to providing a raised portion on the outer peripheral surface of the main body portion and joining the main body portion and the cover, the pressing force to the valve body near the valve shaft hole where leakage is likely to occur is improved and sealed. Performance can be increased.

It is a top view of the seat ring for butterfly valves according to an embodiment of the present invention. It is arrow sectional drawing along line II-II of FIG. FIG. 3 is a cross-sectional view taken along line III-III in FIG. 1. Cross-sectional view taken along line IV-IV in FIG. FIG. 2 is a cross-sectional view of a butterfly valve equipped with the seat ring shown in FIG. 1. FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. 5. FIG. 6 is an enlarged perspective view of a valve body of the butterfly valve shown in FIG. 5. It is explanatory drawing for demonstrating the state at the time of valve closing when a protruding part and a flange part are not spaced apart.

  Hereinafter, a seat ring for a butterfly valve according to the present invention and a butterfly valve using the same will be described with reference to the drawings. However, it goes without saying that the present invention is not limited to this embodiment.

First, the overall configuration of the butterfly valve seat ring 1 will be described with reference to FIGS. 1 to 4.
The seat ring 1 includes a main body portion 11 having a substantially cylindrical peripheral wall extending along the central axis, flange portions 12 provided at both ends of the main body portion 11 in the central axis direction, and a covering body 13. A pair of valve shaft holes 14 extending through the valve shaft hole axis are formed at opposing positions on the peripheral wall of the main body 11. The main body portion 11 and the flange portion 12 are formed of an elastic elastomer material such as chloroprene rubber, ethylene propylene rubber, isoprene rubber, chlorosulfonated rubber, nitrile rubber, styrene butadiene rubber, chlorinated polyethylene rubber, fluorine rubber, and the like. Has been. On the other hand, the covering 13 is made of a resin material such as a fluorine resin material such as polytetrafluoroethylene (PTFE), perfluoroalkoxy alkane (PFA), or polyvinylidene fluoride (PVDF) having chemical resistance. . The covering 13 is provided adjacent to the main body 11 so as to cover the inner peripheral surface of the main body 11 and the inner peripheral surfaces of the pair of valve shaft holes 14. As shown in FIG. 3, the covering body 13 may extend so as to cover at least a part of the flange portion 12 (specifically, an outer portion of the flange portion 12). The main body 11 and the cover 13 are integrally formed by joining the inner peripheral surface of the main body 11 and the inner peripheral surface of the valve shaft hole 14 and the outer peripheral surface of the cover 13. The main body 11 and the cover 13 can be joined by, for example, vulcanization adhesion. As a method of vulcanization adhesion, there are a method of directly bonding the main body 11 and the covering body 13 without using an adhesive and a method of indirectly bonding using an adhesive.

  On the outer peripheral surface of the main body 11, a raised portion 15 that protrudes from the outer peripheral surface of the main body 11 and has a width larger than the diameter of the valve shaft hole 14 is formed around each of the pair of valve shaft holes 14. Is formed. The raised portion 15 is positioned away from both flange portions 12, and a groove portion is formed between each flange portion 12 and the raised portion 15. The raised portion 15 includes a curved section 151 and a connection section 152. The curved section 151 bulges at a certain height t (see FIG. 2) with respect to the outer peripheral surface of the main body 11 and extends curvedly from the valve shaft hole 14 to both sides in the circumferential direction of the main body 11. The height t of the outer peripheral surface of the curved section 151 with respect to the outer peripheral surface of the main body 11 is preferably t / T ≧ 0.12, where T is the thickness of the main body 11, and t / T ≧ 0.32. More preferably. The connection section 152 extends in a planar shape so as to connect between the curved section 151, each of both ends in the circumferential direction of the outer peripheral surface of the curved section 151, and the joining portion 111 on the outer peripheral surface of the main body 11. . As shown in FIG. 2, the connection section 152 is preferably formed so as to extend in the tangential direction at the junction 111. In addition, projection is performed on a plane perpendicular to the axis of the valve shaft hole so that the thickness of the main body 11 does not change suddenly from the portion where the raised portion 16 is not formed on the outer peripheral surface of the main body 11 to the curved section 151 of the raised portion 15. The connecting section along the circumferential direction of the main body 11 when the length L1 between the edge of the valve shaft hole 14 and the both ends of the curved section 151 is projected onto a plane perpendicular to the valve shaft hole axis. The length L2 of 152 is preferably shorter (see FIG. 1).

  Further, as shown in FIG. 1, a plurality of grooves 112 extending in the circumferential direction of the main body 11 are formed on the outer peripheral surface of the main body 11. A groove 112 is formed so that a region on the outer peripheral surface of the main body 11 facing the region (valve seat portion 17) where the outer peripheral surface of the valve body 4 of the butterfly valve 2 to be described later is in pressure contact is sandwiched between adjacent grooves 112. It is preferred that

  On the inner peripheral surface of the cover 13, a spherical valve shaft seal portion 16 is formed around a region where the valve shaft hole 14 opens. A region around the opening of the valve shaft hole 14 of the valve shaft seal portion 16 is formed to protrude inward so as to be thinner than the valve shaft hole 14, and when the valve shaft is inserted into the valve shaft hole 14. In addition, the gap between the outer peripheral surface of the valve shaft 5 for supporting the valve body 4 and the inner peripheral surface of the valve shaft hole 14 is sealed.

  Further, as shown in FIG. 3 and FIG. 4, on the inner peripheral surface of the covering body 13, there is an arc-shaped cross section in a region where the outer peripheral surface of the valve body 4 of the butterfly valve 2 is pressed when the valve is closed. It is preferable that the recessed valve seat part 17 is formed so that it may have.

  5 and 6 show the butterfly valve 2 with the seat ring 1 shown in FIGS. 1 to 4 attached thereto. The butterfly valve 2 includes a valve body 3, a valve body 4, and a seat ring 1.

  The valve body 3 is formed of a resin material. The valve body 3 includes a valve body upper member 31 and a valve body lower member 32. The connection flange 311 of the valve body upper member 31 and the connection flange 321 of the valve body lower member 32 are fixed with bolts or the like. By joining the valve main body upper member 31 and the valve main body lower member 32, an internal flow path 33 extending along the flow path axis is formed inside. In addition, an operation portion flange 312 is provided in the vicinity of the center of the outer periphery of the valve body upper member 31 of the valve body 3, and the valve body upper member 31 and the valve body lower portion face each other in the radial direction of the internal flow path 33. A pair of linear valve shaft support holes 313 and 322 are formed in the side member 32, and the valve shaft support hole 313 formed in the valve body upper member 31 extends to the operation portion flange 312.

  The seat ring 1 is mounted on the inner peripheral surface of the internal flow path 33 of the valve body 3. Specifically, as shown in FIG. 6, the seat ring 1 is arranged in the direction of the central axis of the main body 11 in the fitting recess provided around the opening of the internal flow path 33 at both ends of the valve main body 3. The flange portions 12 formed at both ends of the valve body 3 are fitted, and the valve body 3 is sandwiched between the two flange portions 12 so as to be attached to the internal flow path 33 of the valve body 3. At this time, the seat ring 1 is positioned with respect to the valve body 3 such that the valve shaft hole 14 of the seat ring 1 is aligned with the valve shaft support holes 313 and 322 of the valve body 3.

  The valve body 4 is made of a resin material, and has a substantially disc-shaped valve body main body 41 and a bulging portion 42 that is provided at a position opposite to the radial direction and protrudes from the valve body main body 41. Including. A valve shaft 5 for rotating the valve body 4 is connected to the bulging portion 42 of the valve body 4. The valve shaft 5 is connected to the pair of valve shaft holes 14 of the seat ring 1 and the valve shaft of the valve body 3. The valve body 4 is pivotally supported in the internal flow path 33 of the valve body 3 by being inserted into the support holes 313 and 322. Further, the bulging portion 42 is formed so as to have a contact surface formed so as to contact the valve shaft seal portion 16 on the inner peripheral surface of the covering 13 of the seat ring 1. FIG. 7 shows the outer peripheral surface of the valve body main body 41 that is in pressure contact with the valve seat portion 17 of the seat ring 1 and the contact surface of the bulging portion 42 that contacts the valve shaft seal portion 16 of the seat ring 1 when the valve is closed. As shown, it is preferably formed so as to form a part of a spherical surface.

  In addition, the valve body 3 and the valve body 4 are not limited to those formed from a resin material, and may be formed from, for example, a resin, a metal, or a composite material thereof as long as it is a rigid material. The valve body 3 and the valve body 4 may be formed from different materials. Further, the cover 13 and the valve body 4 or the cover of the valve body may be formed of the same material.

  In the present embodiment, the valve shaft 5 is formed separately from the first valve shaft member 51 formed integrally with the valve body 4 and the valve body 4, and is inserted into the valve body 4. The second valve shaft member 52 is connected to the valve body 4. However, the connection form of the valve body 4 and the valve shaft 5 is not limited as long as the valve body 4 can be rotated by rotating the valve shaft 5. For example, both the first valve shaft member 51 and the second valve shaft member 52 may be formed integrally with the valve body 4, and both the first valve shaft member 51 and the second valve shaft member 52 are formed. May be formed separately from the valve body 4, and the first valve shaft member 51 and the second valve shaft member 52 may be connected to the valve body 4 by, for example, screwing.

  The first valve shaft member 51 extends from the operation portion flange 312 of the valve main body 3, and a lever-type drive unit, a gear-type drive unit, and an automatic drive mounted on the operation unit flange 312 are attached to the projecting portion. The inner periphery of the covering 13 of the seat ring 1 attached to the internal flow path 33 of the valve body 3 by connecting to a driving part (not shown) such as a valve part and rotating the valve body 4 via the valve shaft 5. The valve is opened and closed by pressing and separating the outer peripheral surface of the valve body 4 on the surface.

  In assembling the valve body 3, the seat ring 1, and the valve body 4, in the case of this embodiment, first, the first valve shaft member 51 formed integrally is used as one valve shaft of the seat ring 1. After inserting the valve body 4 in the body portion 11 of the seat ring 1 by inserting into the hole 14, the second valve shaft member 52 is connected to the valve body 4 through the other valve shaft hole 14 of the seat ring 1. Then, an assembly of the valve shaft 5 and the seat ring 1 is created. Next, the first valve shaft member 51 extending through the valve shaft hole 14 of the seat ring 1 is passed through the valve shaft support hole 313 of the valve body upper member 31 and the valve shaft hole 14 of the seat ring 1 is passed through. With the second valve shaft member 52 extending in this manner inserted into the valve shaft support hole 322 of the valve body lower member 32, the connection flange 311 of the valve body upper member 31 and the connection flange 321 of the valve body lower member 32 The seat ring 1 is mounted in the internal flow path 33 formed by the valve body upper member 31 and the valve body lower member 32.

  When using the butterfly valve 2, pipes are connected to the upstream side and the downstream side of the butterfly valve 2, respectively, and fluid passes through the internal flow path 33 of the valve body 3 of the butterfly valve 2. The seat ring 1 is attached to the internal flow path 33 of the valve body 3, and the inner peripheral surface of the body portion 11 of the seat ring 1 and the valve shaft hole 14 with which fluid may come into contact is covered with the covering body 13. Since the fluid is prevented from coming into contact with the main body 11 and the valve body 3, even if the fluid is corrosive, the corrosion and deterioration of the main body 11 and the valve body 3 are suppressed. Can do.

  When the butterfly valve 2 is closed, the valve shaft 5 is rotationally driven by a drive unit attached to the operation unit flange 312 of the valve body 3, so that the valve of the covering 13 of the seat ring 1 attached to the internal flow path 33. By sealing the outer peripheral surface of the valve body 4 against the seat portion 17, the fluid flow in the internal flow path 33 is blocked. The inner diameter of the covering body 13 of the seat ring 1 is smaller than the outer diameter of the valve body 4 at least in the valve seat portion 17, and the outer peripheral surface of the valve body 4 is in the valve seat portion 17 of the covering body 13 of the seat ring 1. When abutting, the main body 11 made of an elastomer material is compressed, and a pressing force is applied so as to press the valve seat portion 17 of the covering body 13 against the outer peripheral surface of the valve body 4. Thereby, the inner peripheral surface (specifically, the valve seat portion 17) of the covering body 13 of the seat ring 1 and the outer peripheral surface of the valve body 4 are pressed and sealed, and the upstream side of the pipe is downstream from the primary side. Is prevented from leaking to the secondary side.

  In the butterfly valve 2, a raised portion 15 is formed around each valve shaft hole 14 of the seat ring 1. When the outer peripheral surface of the valve body 4 comes into contact with the inner peripheral surface of the covering body 13 of the seat ring 1 in a state where the seat ring 1 is mounted in the internal flow path 33 of the valve main body 3, the raised portion 15 becomes the covering body 13. Is pressed against the inner peripheral surface of the internal flow path 33 and compressed. Since the area where the raised portion 15 is provided has a higher compression ratio than the remaining portion of the main body 11 of the seat ring 1 by the thickness of the raised portion 15, a higher pressing force is applied to the covering 13. The peripheral region of the valve shaft hole 14 (valve shaft seal portion 16) is caused to adhere to the peripheral region of the valve shaft hole 14 on the inner peripheral surface of the cover 13 and the outer peripheral surface of the valve body 4. Therefore, it is possible to enhance the sealing effect around the valve shaft hole 14 where leakage is likely to occur, to suppress the occurrence of leakage, and to improve the durability that exhibits a certain sealing performance. Such an effect is t / T ≧ 0.12 where T is the thickness of the main body 11 and t is the height of the raised portion 15 (specifically, the curved section 151) with respect to the outer peripheral surface of the main body 11. And becomes remarkable when t / T ≧ 0.32.

  Further, the connecting portion between the valve body 4 and the valve shaft 5 (specifically, the first valve shaft member 51 and the second valve shaft member 52) has a valve shaft hole 14 on the inner peripheral surface of the covering body 13. A bulging portion 42 that contacts the valve shaft seal portion 16 provided so as to surround the opening is formed, and the valve shaft seal portion 16 of the covering 13 and the contact surface of the bulging portion 42 always come into contact with each other. The pressing force by the compressed ridge 15 acts to press the covering 13 against the bulging portion 42 and the valve shaft 5. As a result, between the valve shaft seal portion of the covering body 13 (region around the opening of the valve shaft hole 14) and the contact surface of the bulging portion 42 and the covering region of the inner peripheral surface of the valve shaft hole 14 in the covering body 13 The valve shaft 5 is pressed against and sealed to prevent leakage from the primary side to the secondary side when the valve is closed, and also prevents external leakage through the valve shaft hole 14 regardless of whether the valve is open or closed. The effect to do.

  If the outer peripheral surface of the valve body 4 is formed so as to form a part of a spherical surface, the outer peripheral surface of the valve body 4 and the valve seat portion 17 are smoothly brought into contact with each other, and the resistance is reduced. In particular, the resistance is further reduced if the valve seat portion 17 is formed to be recessed in an arcuate cross section. If the contact surface of the bulging portion 42 that contacts the valve shaft seal portion 16 of the cover 13 is formed in a spherical shape so as to be complementary to the contact surface of the valve shaft seal portion 16, the valve body 4. The resistance at the time of rotation is further reduced. As a result, an effect of reducing the operation torque of the valve shaft 5 can be obtained.

  In the seat ring 1, the raised portion 15 is configured to include a curved section 151 and a connection section 152. The curved section 151 protrudes from the valve shaft hole 14 at both sides in the circumferential direction of the main body portion 11 and protrudes at a certain height with respect to the outer peripheral surface of the main body portion 11. Therefore, when the valve is closed, the curved section 151 causes a uniform effective surface pressure (pressing force) to act on the contact surface of the bulging portion 42 of the valve body 4 and the outer peripheral surface of the valve body main body 41, thereby leaking. Suppresses the occurrence of On the other hand, the connection section 152 extends in a planar shape in the tangential direction at the junction 111 between the raised portion 15 and the main body portion 11. Accordingly, the effective surface pressure that the seat ring 1 acts on the valve body 4 smoothly changes from the region where the raised portions 15 are not provided to the region where the raised portions 15 are provided, and a sudden change can be avoided. , Leakage to the secondary side is less likely to occur. In this respect, for example, when the raised portion 15 is formed so as to be a part of a circle deviated from the center of the main body portion 11 toward the raised portion side, the effective surface pressure is drastically reduced in the merged portion. This tends to cause leakage to the secondary side. Also, when projected onto a plane perpendicular to the valve shaft hole axis rather than the length L1 between the edge of the valve shaft hole 14 and both ends of the curved section 151 when projected onto a plane perpendicular to the valve shaft hole axis. If the length L2 of the connection section 152 along the circumferential direction of the main body portion 11 is increased, the change in the effective surface pressure along the outer peripheral surface of the valve body 4 in the vicinity of the raised portion 15 at the time of valve closing occurs. It is possible to achieve an effect of becoming gentle and less likely to cause leakage.

  If the raised portion 15 is provided adjacent to both flange portions 12, the flange portion 12 is deformed so as to be pushed outward by the compressed raised portion 15 as shown in FIG. There is a risk that. However, as shown in FIGS. 1 to 4, in the seat ring 1, the raised portions 15 are located apart from both flange portions 12, and a groove portion is formed between each flange portion 12 and the raised portions 15. In addition, since the bulge 15 functions as a clearance when the bulge 15 is deformed during compression, the deformation of the flange 12 as described above can be prevented. Further, when the valve is closed, the outer peripheral surface of the valve body 4 comes into pressure contact with the valve seat portion 17 of the seat ring 1, and the region of the main body portion 11 adjacent to the valve seat portion 17 is intensively compressed. The groove 112 of the main body portion 11 functions as an allowance for deformation of the main body portion 11 due to the compression of the above-described region, and compensates for the elastic deformation of the main body portion 11, and the outer peripheral surface of the valve body 4 and the valve seat portion of the seat ring 1. It fulfills the function of assisting adhesion.

  The seat ring for a butterfly valve and the butterfly valve using the same according to the present invention have been described above with reference to the illustrated embodiment. However, the present invention is not limited to the embodiment. For example, in the illustrated embodiment, the connection section 152 of the raised portion 15 extends in a planar shape in the tangential direction in the merge portion 111, but the connection section 152 is not limited to a planar shape, and has a gently curved surface. It may be.

DESCRIPTION OF SYMBOLS 1 Seat ring 2 Butterfly valve 3 Valve main body 4 Valve body 5 Valve shaft 11 Main body part 12 Flange part 13 Cover body 14 Valve shaft hole 15 Raised part 33 Internal flow path 111 Merge part 112 Groove 151 Curved part 152 Connection part

Claims (8)

A butterfly valve which is mounted on the inner peripheral surface of an internal flow path extending along the flow path axis in the valve body of the butterfly valve, and abuts on the outer peripheral surface of the valve element pivotally supported in the internal flow path Seat ring for
A body portion made of an elastomer material having a substantially cylindrical peripheral wall and having a pair of valve shaft holes extending through the valve shaft hole axis at opposite positions of the peripheral wall;
A cover made of a resin material provided to cover the inner peripheral surface of the main body and the inner peripheral surface of the pair of valve shaft holes;
On the outer peripheral surface of the main body, a raised portion formed around each of the pair of valve shaft holes;
The body and the covering are joined and formed integrally ,
The raised portion is raised at a certain height with respect to the outer peripheral surface of the main body portion and extends in a curved direction in the circumferential direction of the main body portion, and both circumferential ends of the outer peripheral surface of the curved portion. A planar connecting section extending between each and the merging section on the outer peripheral surface of the main body, and the connecting section extends in a tangential direction at the merging section and is projected onto a plane perpendicular to the valve shaft hole axis. In this case, the length L1 of the curved section extending on both sides of the valve shaft hole is shorter than the length L2 of the connection section when projected onto a plane perpendicular to the valve shaft hole axis. Seat ring for the butterfly valve. The seat ring for a butterfly valve according to claim 1 , wherein the main body and the covering are joined by vulcanization adhesion. The butterfly according to claim 1 or 2 , wherein the seat ring further includes a flange portion at both ends of the main body portion in the flow path axis direction, and the raised portion is provided apart from the flange portion. Seat ring for valves. The butterfly valve seat ring according to any one of claims 1 to 3 , wherein a plurality of grooves extending in a circumferential direction are formed on an outer peripheral surface of the main body portion. The butterfly valve seat ring according to any one of claims 1 to 4 , wherein the covering is made of a fluororesin material. A valve body having an internal flow path extending along the flow path axis inside;
The seat ring according to any one of claims 1 to 5 , wherein the seat ring is attached to an inner peripheral surface of the internal flow path.
A valve shaft extending through the valve shaft hole of the seat ring;
A valve body rotatably supported by the valve body by the valve shaft;
And opening and closing by rotating the valve body within the valve body to press and separate the outer peripheral surface of the valve body from the inner peripheral surface of the covering body of the seat ring. Butterfly valve. The butterfly valve according to claim 6 , wherein an outer peripheral surface of the valve body that abuts on an inner peripheral surface of the covering body is formed in a spherical shape. The butterfly valve according to claim 6 or 7 , wherein the valve body has a spherical contact surface that contacts a peripheral region of the valve shaft hole on an inner peripheral surface of the seat ring.

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