JP2005133810A - Butterfly valve and its component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily manufacture a butterfly valve free from the leakage of fluid by providing and using components of a simple constitution for preventing the leakage of the fluid flowing in a valve main body, from the circumference of a valve shaft of the butterfly valve. <P>SOLUTION: In this component, a cylinder or a cylindrical column is used, a step is formed on a middle in the longitudinal direction of an outer face, one end side of the step is a large-diameter part, the other end side is a small-diameter part, an annular projection raised toward an end at the small-diameter part side and extended in the circumferential direction is formed on a step surface to be used as a contact part with a seat ring outer peripheral face, a flange to be fixed to the valve main body, is formed on an end of the large-diameter part, and an outer peripheral face of the small-diameter part is applied as a sliding face to a valve element. The component using the cylinder is used in a bearing of a driving shaft in assembling the butterfly valve, and the component using the cylindrical column is used in a driven shaft in assembling the butterfly valve. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a butterfly valve and its components, that is, a valve shaft and a valve shaft bearing.

  A butterfly valve is attached to a pipe and used to control a fluid flowing in the pipe. In the butterfly valve, a disc-like valve body is rotatably provided in a circular fluid passage provided in the valve body, and the fluid passage is opened and closed by the rotation of the valve body, thereby controlling the fluid. Is for. Therefore, the butterfly valve is mainly composed of a rigid material valve body having a tubular fluid passage and a rigid material valve body attached to the fluid passage of the valve body so as to be rotatable by a valve shaft. It is said.

  In addition, in the butterfly valve, when the valve body closes the fluid passage, a seat ring is used for airtightness between the outer periphery of the valve body and the fluid passage. A seat ring is a tubular part of a butterfly valve made of an elastic material such as rubber, and is fixed to the wall surface of the fluid passage. When the valve body closes the fluid passage, the wall surface of the fluid passage and the outer periphery of the valve body This is to eliminate the gap between the two.

  In the butterfly valve, a valve shaft that supports the valve body is attached in order to enable the valve body to rotate within the seat ring. The valve shaft extends in the diameter direction through the lumen of the seat ring, and both ends thereof penetrate the wall of the seat ring and further penetrate the wall of the fluid passage of the valve body.

  The valve shaft is often composed of a single round bar penetrating the valve body, but may also be composed of two round bars that are separated and aligned in the center of the valve body. In any case, the valve shaft is fixed to the valve body and serves as a drive shaft for rotating the valve body. The end of the drive shaft protrudes greatly from the valve body and is connected to the actuator.

  As described above, in the butterfly valve, the drive shaft protrudes through the seat ring and the valve body in order to rotate the valve body. It must be prevented from leaking out of the room. For this purpose, the valve body is provided with a cylindrical shaft support for accommodating the drive shaft so that fluid does not leak around the drive shaft in the shaft support.

  In the butterfly valve, preventing the fluid from leaking from around the valve shaft is usually called a shaft seal. In general, it is more difficult to seal the shaft when the valve shaft rotates than when the valve shaft is stationary without rotating. Accordingly, it is generally difficult to seal the drive shaft that serves to rotate the valve body. For this reason, special ideas have been put on the shaft seal of the drive shaft.

  In the past, butterfly valve shaft seals were made around seat ring holes through which the valve shaft penetrated. For example, a metal core that just surrounds the valve shaft is built into the seat ring to prevent the through hole of the seat ring from deforming and moving away from the valve shaft. The shaft seal was made by inserting a stubby to make contact with the valve shaft, or by pressing the backup ring from the surface of the seat ring so that the periphery of the through hole was always in close contact with the valve shaft. However, this could not satisfy the shaft seal.

In addition, attempts have been made to complete the shaft seal by attaching bushes or bearings around the valve shaft. For example, Japanese Patent Application Laid-Open No. 60-1475 describes that a long bush that passes through the seat ring from the valve body and reaches the valve body is attached, and an O-ring is attached to the outer peripheral surface of the bush for shaft sealing. doing. Japanese Patent Application Laid-Open No. 2002-181203 provides a bearing that penetrates the seat ring from the valve body and reaches the valve body, an O-ring is attached to the inner and outer surfaces of the bearing, and a special sealing material is attached to the end. I am trying to seal the shaft.
Japanese Unexamined Patent Publication No. 60-1475 JP 2002-181203 A

  However, since the outer surface of the bush or the bearing is a simple cylindrical surface and only an O-ring or a special sealing material is attached thereto, a satisfactory shaft seal has not been achieved. Also, the use of a special sealing material is not suitable for practical use because the structure is complicated and the assembly of the butterfly valve is complicated. Therefore, it was necessary to perform satisfactory shaft sealing by a simpler method.

  The present invention was born in accordance with the above-described needs. That is, the present invention is intended to easily and reliably prevent leakage of fluid flowing in the fluid passage from around the valve shaft using a simple structure. In particular, the present invention is intended to reliably prevent fluid leakage from around the drive shaft on which the valve shaft rotates.

  This inventor decided to provide a bearing around the valve shaft of the butterfly valve, as taught in the above-mentioned patent publication, but provided a step in the middle of the outer surface without making the outer surface of the bearing a simple cylindrical surface. Then, an attempt was made to seal the shaft by providing an annular protrusion that protrudes in the length direction of the bearing on the step surface and extends in the circumferential direction, and the protrusion is brought into close contact with the outer peripheral surface of the seat ring. In addition, the bearing is a long one that penetrates the seat ring from the valve body and reaches the valve body, the valve body is provided with a crocodile flange, and the valve body is fixed with a crocodile bolt. In this way, when the flange is fixed, the inventor has found that the protrusions are brought into close contact with the outer surface of the seat ring, and a sufficient shaft seal is obtained therebetween. In addition, it has been found that this makes the assembly of the butterfly valve simple and easy.

  Furthermore, the inventor has found that the structure of the bearing can be used for the valve shaft. The present invention has been completed based on such knowledge.

  The present invention includes a valve body provided with a tubular fluid passage, a tubular seat ring fixed to the inner wall of the fluid passage, a valve shaft that passes through the wall of the seat ring and is fixed to the wall of the fluid passage, In a butterfly valve comprising a valve body that is rotatably supported by a valve shaft, a bearing is provided around a drive shaft that functions to rotate the valve body of the valve shaft. A step is provided in the middle of the length direction, the part from the step to one end is made large in diameter, the part from the step to the other end is made small in diameter, and the small diameter rises toward the end of the step on the step surface, An annular protrusion extending in the circumferential direction is provided, the protrusion is used as a contact portion to the outer peripheral surface of the seat ring, a flange for fixing to the valve body is provided at the end of the large diameter flange, and the outer peripheral surface of the small diameter flange is provided as a valve. Using a slide surface to the body, let the small diameter wrinkle enter the valve body and Secure the di to the valve body, characterized in that the shaft sealing projections are in close contact to the outer peripheral surface of the seat ring, there is provided a butterfly valve.

  The present invention also provides parts used in the configuration of the butterfly valve, that is, a bearing or a valve shaft. In the invention relating to the component, a step is provided in the middle of the length direction of the cylindrical outer surface, a part extending from the step to one end is increased in diameter, a part extending from the step to the other end is decreased in diameter, and a small diameter is formed on the step surface. An annular projection that protrudes toward the end of the flange and extends in the circumferential direction is used as a contact portion to the outer peripheral surface of the seat ring, and a flange for fixing to the valve body is provided at the end of the large diameter flange. The outer peripheral surface of the small diameter wrinkle is a sliding surface for the valve body.

  Among the above-mentioned components, a bearing is a bearing in which a through hole extending in the central axis direction is provided inside a cylinder and the inner surface of the through hole is a sliding surface with the valve shaft. This bearing can be used as a valve shaft by leaving the through hole as it is and making it thick, or by eliminating the through hole and making the inside solid.

  That is, among the above parts, those that do not have the above-described through-holes, more specifically, the inside of the cylinder is solid and has no depression, or even if there is a depression, the end of the depression is closed and the center axis of the cylinder is There is a partition extending in the vertical direction, and the valve shaft is reinforced.

  The butterfly valve component according to the present invention is provided with a step in the middle of the length of the cylindrical outer surface, the diameter from the step to one end is increased in diameter, the portion from the step to the other end is decreased in diameter, The small-diameter has a simple structure in which an annular protrusion is provided which protrudes toward the end of the flange, extends in the circumferential direction, and a flange is provided at the end of the large-diameter, so that its manufacture is easy. .

  In the butterfly valve according to the present invention, a seat ring is attached in the valve body, and after inserting the valve body in the seat ring, the above-mentioned bearing is inserted from the valve body with the small diameter first, and then After inserting the drive shaft, the outer peripheral surface of the small diameter flange is inserted into the valve body, the protrusion is brought into contact with the outer peripheral surface of the seat ring, and the flange of the large diameter flange is fixed to the valve body. This makes it easy to assemble the butterfly valve.

  In the butterfly valve made in this way, the protrusion extends in an annular shape around the valve shaft, and the cross section of the protrusion has a mountain shape, and the tip of the protrusion contacts the outer peripheral surface of the seat ring made of an elastic material. The contact surface between the protrusion and the seat ring is a surface that is bent and spreads in the radial direction around the valve shaft. Therefore, a contact surface having a sufficiently wide contact is formed between the protrusion and the seat ring. Therefore, a sufficient shaft seal is achieved. In particular, if a groove is dug in the contact portion of the protrusion on the outer periphery of the seat ring, the contact surface can be further expanded, so that a more complete shaft seal can be achieved. The present invention provides such an effect.

  An embodiment of the present invention will be described with reference to the drawings as follows. FIG. 1 shows a bearing for a butterfly valve according to the present invention, in which (a) is a plan view thereof, and (b) is a sectional view taken along line BB of (a). 2A and 2B show a valve shaft for a butterfly valve according to the present invention, in which FIG. 2A is a plan view and FIG. 2B is a sectional view taken along line BB in FIG. FIG. 3 is a cross-sectional view of the butterfly valve according to the present invention. 4 and 5 are enlarged cross-sectional views of a part of the butterfly valve shown in FIG.

  The components of the butterfly valve according to the present invention include a part that can be used as a bearing and a part that can be used as a valve shaft. Among them, a part that can be used as a bearing is the bearing X shown in FIG.

  As shown in FIG. 1, the bearing X has a cylindrical outer surface 2. The inside is hollow, and the inner surface 1 is in contact with the valve shaft of a butterfly valve described later and becomes a sliding surface with the valve shaft. The outer surface 2 is provided with a step 3 in the middle in the length direction, and a portion from the step 3 to one end has a large diameter as a large diameter portion 4, and a portion from the step 3 to the other end has a small diameter as a small diameter portion 5.

  A protrusion 6 is provided on the surface of the step 3. The projection 6 has a small-diameter portion 5 that protrudes toward the edge of the flange and extends in the circumferential direction to form an annular shape. A flange 7 is provided at the end of the large diameter portion 4. The flange 7 is provided with a bolt insertion hole 8 for fixing. Further, the inner surface 1 and the outer surface 2 are provided with grooves 9 for inserting O-rings.

  Of the components of the butterfly valve according to the present invention, the valve shaft Y has a cylindrical shape as shown in FIG. The valve shaft Y shown in FIG. 2 differs from the bearing X shown in FIG. 1 only in that it does not have a through hole inside. In other words, the outer surface 2 of the valve shaft Y has a cylindrical shape, and includes a step 3 in the middle in the length direction. A portion reaching the end is made a small diameter to form a small diameter portion 5.

  Further, the valve shaft Y has a protrusion 6 on the surface of the step 3. The projection 6 has a small-diameter portion 5 that protrudes toward the edge of the flange and extends in the circumferential direction to form an annular shape. A flange 7 is provided at the end of the large diameter portion 4. The flange 7 is provided with a fixing bolt hole 8. In these respects, the valve shaft Y is the same as the bearing X.

  Inside the valve shaft Y, a partition wall 10 extending perpendicularly to the central shaft is attached, and the valve shaft Y is reinforced. However, the partition wall 10 is not always necessary. This is because it can be sufficiently reinforced by increasing the thickness of the hollow body. Therefore, the above-mentioned bearing X can be used as a valve shaft as it is by increasing its thickness.

  It is desirable that the valve shaft Y shown in FIG. 2 is actually solid and filled with the partition wall 10. However, when the valve shaft Y is made of a synthetic resin or the like, if the interior is full, a recess is formed in the outer shape due to the shrinkage of the resin during molding. Therefore, a recess 90 is formed in the interior to prevent this. Has been.

  The bearing and valve shaft according to the present invention are used to assemble a butterfly valve Z as shown in FIG. The butterfly valve Z includes a valve body 11, a seat ring 12, a valve shaft 13, and a valve body 14. The valve body 11 includes a circular fluid passage 15 inside, and the seat ring 12 is fixed to the wall surface of the fluid passage. The valve shaft 13 penetrates the wall of the fluid passage of the seat ring 12 and the valve body 11 in the diametrical direction. The valve body 14 is fixed to the valve shaft 13 and rotated by the valve shaft 13. Therefore, the valve shaft 13 is a drive shaft.

  In the bearing X according to the present invention, the seat ring 12 is fixed to the valve body 11, and then the valve body 14 is installed at a predetermined position. Then, the bearing X is inserted from the valve body 11 into the valve shaft with the small diameter portion 5 first. It is used to assemble the butterfly valve by inserting the valve shaft 13 after that. At this time, the outer surface of the bearing X is in close contact with the valve body 11, the seat ring 12, and the valve body 14, and there is no gap between them.

  In a state where the bearing X is incorporated in the butterfly valve Z, as shown in an enlarged view in FIG. 4, the inner surface of the bearing X is in contact with the valve shaft 13 to form a sliding surface with the valve shaft 13. Yes. Further, the protrusion 6 attached to the outer surface of the bearing X abuts on the outer peripheral surface of the seat ring 12 and forms a close contact therewith to seal the shaft. Further, the small diameter portion 5 of the bearing X enters the valve body 14, and the outer surface of the small diameter portion 5 forms a sliding surface with the valve body 14.

  In order to ensure a shaft seal between the protrusion 6 of the bearing X and the seat ring 12, an annular shape is formed around the valve shaft insertion hole on the outer peripheral surface of the seat ring 12, as shown in FIG. It is preferable to dig a groove so that the tip of the protrusion 6 fits into the groove. Further, it is preferable that the portion of the seat ring located between the protrusion 6 and the valve shaft 13 enters into a recess formed inside the protrusion 6 so as to be in close contact.

  In the bearing X, the valve body 11 is fixed to the crocodile by bolting the flange 7 to the valve body 11. Therefore, the valve shaft 13 has a structure that only contacts the bearing X and does not contact the valve body 11 and the seat ring 12. Therefore, the valve shaft 13 only slides with the bearing X when the valve is opened and closed. Further, when the valve is opened and closed, the seat ring 12 only slides with the valve body 14 at a slight portion around the bearing X. The seat ring 12 is made of an elastic material and easily wears out. However, since the sliding surface occupies a small portion as described above, the wear is small, and therefore the shaft seal is kept for a long time. Can do.

  As shown in FIG. 4, the bearing X is fixed to the valve body 11 through a bolt from above a pressing plate 71 having the same shape as the flange 7 on the flange 7. The presser plate 71 is divided into two parts for allowing the valve shaft 13 to pass therethrough, and the portion that comes into contact with the valve shaft 13 is fitted into a groove provided in the valve shaft 13 so that the valve shaft 13 comes out. Is prevented.

  Further, by fitting an O-ring in the groove 9 provided in the inner surface 1 and the outer surface 2 of the bearing X, the shaft seal can be further ensured.

  In the butterfly valve Z shown in FIG. 3, only the entire inner surface of the bearing X and the portion of the outer surface of the bearing X in contact with the valve body 14 slide when the valve is opened and closed. Therefore, these sliding surfaces are referred to as “clearance fit”. In addition, the space between the valve element 14 and the seat ring 12 is “tight fit”, and the space between the bearing X and the seat ring 12 is “intermediate fit”. By doing so, the valve can be easily opened and closed and the shaft seal can be satisfied.

  The bearing and valve shaft according to the present invention can be made of metal, but can also be made of hard synthetic resin.

  The butterfly valve Z shown in FIG. 3 does not support the valve body with one valve shaft, but supports it with two valve shafts. That is, the valve shaft 16 is used in addition to the drive shaft 13. The valve shaft 16 is not fixed to the valve body 14, and the valve body 11 is fixed to the crocodile. Therefore, the valve shaft 16 does not rotate together with the valve body 14 but only supports the valve body 14. Such a valve shaft 16 is called a driven shaft with respect to the drive shaft.

  The butterfly valve Z shown in FIG. 3 uses the valve shaft Y shown in FIG. 2 as the driven shaft 16. That is, the driven shaft 16 is turned upside down with respect to the valve shaft Y shown in FIG. 2 and inserted from the bottom of the valve body 11 with the small diameter portion 5 first, passes through the seat ring 12 and the small diameter portion 5 is inserted into the valve body 14. Attached to the inside. Although not shown in FIG. 3, the flange 7 of FIG. 2 is fixed to the valve body 11 with bolts, and the valve shaft Y is used for assembling the butterfly valve. In these respects, the valve shaft Y is the same as the bearing X.

  In the butterfly valve Z made in this way, the protrusion 6 is dug on the outer peripheral surface of the seat ring 12 as shown in the enlarged view of the valve shaft Y in FIG. The shaft seal is completed by fitting in the annular groove. Since the valve main body of the valve shaft Y is fixed to the crocodile, the valve shaft Y does not slide between the seat ring 12 and, therefore, the shaft seal between the protrusion 6 and the seat ring 12 is hardly broken. It has become a thing.

  As shown in FIG. 5, in the butterfly valve Z, the valve shaft Y rotates with the valve body 14 as a sliding surface between the outer surface of the small diameter portion 5 of the valve shaft Y and the surface in contact with the seat ring 12 when the valve is opened and closed. . Thus, since the valve body 14 is only a sliding part of the surface of the seat ring 12 between the valve ring 14 and the seat ring 12, wear of the seat ring is small, and therefore the shaft seal is maintained for a long time. Can do. In this respect, the valve shaft Y is the same as the bearing X.

  As described above, the components of the butterfly valve according to the present invention can be used as bearings in the drive shaft of the butterfly valve and can be used as valve shafts in the driven shaft. When this component is used, the butterfly valve can be easily assembled, the shaft can be easily sealed, and the wear of the seat ring is reduced, so that the life of the butterfly valve can be extended.

The components of the butterfly valve concerning this invention are shown, (a) is a top view and (b) is a BB line sectional view of (a). The other component of the butterfly valve which concerns on this invention is shown, (a) is a top view, (b) is the BB sectional drawing of (a). It is sectional drawing of the butterfly valve which concerns on this invention. FIG. 4 is a partially enlarged cross-sectional view of the butterfly valve according to the present invention shown in FIG. 3. FIG. 4 is an enlarged cross-sectional view of another part of the butterfly valve according to the present invention shown in FIG. 3.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inner surface 2 Outer surface 3 Level | step difference 4 Large diameter part 5 Small diameter part 6 Protrusion 7 Flange 8 Hole 9 Groove 10 Bulkhead 11 Valve main body 12 Seat ring 13 Valve shaft (drive shaft)
14 Valve body 15 Fluid passage 16 Valve shaft (driven shaft)
71 Holding plate 90 Recess X Bearing according to the present invention Y Valve shaft according to the present invention Z Butterfly valve according to the present invention

Claims (6)

  Provide a step in the middle of the length of the cylindrical outer surface, increase the diameter from the step to one end, decrease the diameter from the step to the other end, and decrease the diameter on the step surface toward the edge of the flange. An annular projection that protrudes and extends in the circumferential direction is provided, and the projection serves as a contact portion with the outer peripheral surface of the seat ring. A flange for fixing to the valve body is provided at the end of the large diameter flange. A butterfly valve component, characterized in that the surface is a sliding surface to the valve body.   2. The butterfly valve bearing according to claim 1, wherein a through hole extending in a central axis direction is provided inside the cylinder, and an inner surface of the through hole is a sliding surface with the valve shaft. 3.   The valve shaft of the butterfly valve according to claim 1, wherein the inside of the cylinder is solid or has a hole penetrating in the direction of the central axis.   A valve body having a tubular fluid passage, a tubular seat ring fixed to the inner wall of the fluid passage, a valve shaft passing through the seat ring and fixed to the wall of the fluid passage, and rotatable by the valve shaft A butterfly valve comprising: a valve body supported by the shaft, wherein the bearing according to claim 2 is provided around a drive shaft that functions to rotate the valve body of the valve shaft, and the bearing has a small diameter outer periphery of the flange. A butterfly valve characterized in that the surface is a sliding surface with the valve body, the protrusion is in contact with the outer peripheral surface of the seat ring, the flange is fixed to the valve body, and the shaft is sealed.   The valve shaft according to claim 3 is used as another valve shaft, the outer peripheral surface of the small diameter flange of the valve shaft is used as a sliding surface with the valve body, the protrusion is in contact with the outer peripheral surface of the seat ring, and the flange is the valve body. The butterfly valve according to claim 4, wherein the butterfly valve is fixed to the shaft and sealed. The butterfly valve according to claim 4 or 5, wherein a groove is dug in the outer peripheral surface of the seat ring with which the protrusion abuts, and the protrusion is fitted into the groove to seal the shaft.

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