JP3348966B2 - Valve opening holding mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve opening holding mechanism.

[0002]

2. Description of the Related Art For example, ball valves used in water pipes and the like,
In an on-off valve such as a butterfly valve, one end thereof is generally attached to a bonnet attached orthogonally to the outside of a tubular valve case, and is attached to the bonnet so as to be rotatable around the axis of the bonnet. A valve body having a ball shape or a disk shape attached to the tip of the valve stem is attached to the flow path in the valve case. By
The opening of the valve body is adjusted. As a configuration for adjusting the opening degree of such a valve, for example, a worm gear system or a lock lever system has conventionally been adopted.

In the worm gear system, a worm wheel is fixed to an end of a valve stem, and a worm meshing with the worm wheel is fixed to a worm shaft arranged at right angles to the valve stem.
The opening degree of the valve body is maintained by the difference in moment of force generated by the so-called worm gear having such a configuration.

On the other hand, in the lock lever system, a lock ring made of, for example, urethane resin and having a projection on the inner periphery is fixed to the upper part of the bonnet, and a projection engaging with the projection of the lock ring is provided on the outer periphery. An appropriate element is fixed to the outer periphery of the upper portion of the valve stem, and the opening of the valve body is maintained by the engagement of the projection.

[0005]

However, according to the worm gear system, the structure becomes complicated as a whole, and the cost increases accordingly. In addition, since the worm shaft is arranged at right angles to the valve stem, there is a possibility that the worm shaft cannot be mounted in a narrow space where pipes, ducts, other valves and the like are congested.

According to the latter lock lever system, the structure is simplified, but since it is held by interlocking the projections, torque cannot be adjusted and operability is poor. Moreover, when the operation is repeated, the projections may be worn and may not be able to be maintained at a desired opening degree.
Also, the opening could not be adjusted and maintained basically continuously in a stepless manner.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and has a simple structure. The cost can be kept low and the valve opening can be continuously and continuously adjusted, and the torque can be freely adjusted. An object of the present invention is to provide a valve opening holding mechanism to solve the above problem.

[0008]

To achieve the above object, according to the present invention, one end of the bonnet is attached to the outside of the tubular valve case at right angles, and the bonnet is mounted around the axis of the bonnet. A valve stem provided in the bonnet so as to be rotatable, and a valve body attached to the stem and capable of shutting off a flow path in a valve case by rotation of the stem. A mechanism for holding an opening of a body, wherein a support member is fixed to an outer periphery of the bonnet and a brake surface is provided on a valve case side surface on an outer periphery of a valve rod protruding from the other end of the bonnet. Fixing the member, a pressing plate pressed from the bonnet side against the locking member,
A valve member is provided so as to be slidable in the axial direction of the valve stem, and an urging member for urging the pressing plate toward the locking member is interposed between the pressing plate and the supporting member. Thus, a valve opening holding mechanism is provided. The brake surface as used herein refers to a surface whose surface is roughened to increase frictional resistance.

According to a second aspect of the present invention, the above-described brake surface is provided not on the locking member but on the pressing plate side. Further, in the third aspect, the brake surface is provided on both the locking member and the pressing plate.

[0010] In the opening degree holding mechanism configured as described above, if the strength of the urging force of the urging member can be adjusted freely as described in claim 4, more preferable operation and effect can be obtained.

In such a case, as described in claim 5,
The biasing member is formed by a coil spring, and further has one end fixed to the support member side and the other end around a support shaft configured to freely project through the pressing plate.
The coil spring may be provided, and an adjusting nut may be screwed onto a protruding end of the support shaft.

According to a sixth aspect of the present invention, the urging member is constituted by a coil spring, and the coil spring fixes one end of the supporting shaft covered with the coil to the pressing plate side, and the other end of the supporting shaft has the other end. May be configured to project freely, and an adjusting nut may be screwed onto a protruding end of the support shaft.

[0013]

According to the first aspect, the pressing plate is urged toward the locking member by the urging member interposed between the pressing plate and the support member, and is pressed against the brake surface of the locking member. You. Since the surface of the brake surface is rough as described above, the frictional resistance is large. Therefore, an extremely large frictional force is generated by the pressing of the pressing plate against the brake surface. Therefore, even if the valve stem tries to rotate due to the pressure received by the valve body from the fluid flowing in the valve case, the rotation of the valve stem is prevented by the pressing and the frictional force, and the opening of the valve body is maintained as it is. . To open and close the valve, for example, an operation lever or the like may be fixed to the valve stem, and the valve stem may be rotated by turning this lever against the frictional force.
Therefore, the valve can be continuously opened and closed continuously.

According to the second aspect, contrary to the first aspect, the brake surface is formed on the pressing plate side. However, the pressing surface of the pressing plate against the locking member side is extremely similar to the first aspect. A large frictional force is generated, the rotation of the valve stem is prevented by the pressing and the frictional force, and the opening of the valve body is maintained as it is.

Further, since the brake surface is provided on both the locking member and the pressing plate, the frictional force generated by pressing the pressing plate on the locking member side can be reduced. Therefore, the present invention can be applied to a valve having a larger fluid pressure than that of the first and second embodiments.

As described in the fourth aspect, if the strength of the biasing force of the biasing member is configured to be adjustable, the magnitude of the pressing force (drag) generating the frictional force can be changed. Therefore, the necessary torque for maintaining the opening can be easily set in accordance with the pressure of the fluid flowing in the valve case.

In such a case, according to the fifth and sixth aspects, the extended state of the coil spring can be changed by appropriately tightening and loosening the adjusting nut, so that the urging force can be easily changed. It has become. In the fifth and sixth aspects, since the pressing force is obtained by the urging force of the coil spring, for example, when the operation lever is fixed to the valve stem and the valve stem is rotated as described above, a smoother opening / closing operation is performed. In order to obtain the lever, for example, this operating lever is provided with a function of "lever" in which an action point is set at a position where the coil spring is contracted, and the urging force of the coil spring is temporarily released by pushing up or down the lever. In this case, the frictional force for maintaining the opening degree is released, and the valve can be opened and closed with a smaller force.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a cross section of a butterfly valve 1 adopting the present embodiment, and a valve case 2 used in the butterfly valve 1. Is made by cutting a pipe material such as a commercially available steel pipe or scrap pipe into a required length, and at one end (the right end in the figure) is a flange part 3, which is open like a trumpet.
A ball seat 5 having an annular recess 4 is formed on the other end. The collar portion 3 is formed by cutting a commercially available steel pipe or scrap pipe into round sections, and expanding and forming the ends thereof by using, for example, a Belling processing method, and thereafter performing laser beam welding on the expanded pipe section.
Is fixed to the outer periphery of one end portion of the base member.

At the center of the valve case 2, a lower end of a bonnet 6, which is also made of a commercially available steel pipe or scrap pipe, is fixed to the outer periphery of the valve case 2 so as to be orthogonal to the valve case 2. . In the illustrated example, the bonnet 6 is attached by fixing the lower end of the bonnet 6 to the outer periphery of the valve case 2 by welding. In fixing the bonnet 6 in this case, first, as shown in FIG. 2, a circular flat portion 2a is formed at a predetermined position of the valve case 2, and an insertion hole 2b for a valve rod 7 described later is formed in the flat portion.
If the lower end surface of the bonnet 6 is fixed to the flat portion 2a after that, the lower end surface of the bonnet 6 does not have to be formed in a so-called "saddle shape" in accordance with the outer shape of the valve case 2.

The upper end of the bonnet 6 is formed into a slotted tapered shape with a thread cut on the outer periphery, and a flange 11 serving as a support member is fixed to the upper outer periphery of the bonnet 6. . The valve stem 7 is rotatably inserted into the bonnet 6, and the lower end of the insertion protrudes into the valve case 2 from the insertion hole 2b, and a disc-shaped valve body 8 is provided at the protruding end. Installed.

On the other hand, about one third of the upper part of the valve stem is
An annular recess 7a is formed near the upper end of the valve stem 7 in the bonnet 6, and an O-ring 9 is fitted in the annular recess 7a. The O-ring 9 is pressed by the tightening of the presser cap 10 to be tightened, and the watertightness between the bonnet 6 and the valve stem 7 is firmly secured.

It is necessary to prevent the valve stem 7 from slipping out of the bonnet 6, but in order to satisfy such a requirement, for example, the lower end portion of the valve stem 7 is fixed to the valve body 8 or FIG. As shown in FIG.
b, and this annular convex portion 7b is
4 may be engaged with the inner surface of the valve stem 7. Further, as shown in FIG. The inner wall of the bonnet 6 may be protruded from the outer periphery of the bonnet 6 into the annular concave portion 7c by so-called "doweling" as shown by X in the figure as shown in FIG.

The opening holding mechanism according to this embodiment is
The flange 11 is configured as a support member. That is, first, a doughnut-shaped substrate 12
The lower ends of a total of four support shafts 13 are fixed at intervals of 0 °, and the substrate 12 is fixed to the substrate 11 through holes 11 a formed in the flange 11 by fixing members 14 such as bolts and nuts. It is fixed to the flange 11. The upper end of the support shaft 13 has a small diameter, and the small diameter portion 13a is threaded.

On the other hand, the pressing plate 15 has the form as shown in FIG. 5, and the hole 1 through which the valve rod 7 passes rotatably.
5a are provided at the center thereof, and small holes 15b in which only the small-diameter portion 13a of the support shaft 13 can slide and protrude are formed at four positions at a central angle of 90 ° in the vicinity of the peripheral portion as shown in FIG. Have been. After covering the outer circumference of the four support shafts 13 with the coil springs 16, respectively, the small diameter portions 13a are made to protrude from the small holes 15b. As shown in FIGS. 1 and 6, adjustment nuts 17 are screwed to the small diameter portions 13a. Accordingly, by appropriately tightening or loosening the adjusting nut 17, the degree of compression of the coil spring 16 changes, and the urging force of the pressing plate 15 can be adjusted accordingly.

In this embodiment, a locking ring 18 as shown in FIG. 7 is employed as a locking member pressed by the pressing plate 15. As shown in the drawing, the locking ring 18 has a convex portion 18a formed at the center on the upper surface side, and the hole 18 through which the valve stem 7 passes vertically along with the convex portion 18a.
b is drilled at the center. The lower surface of the locking ring 18 is provided with a brake surface 18c whose surface is roughly formed.

Then, as shown in FIG. 1, an appropriate fixing screw 19 is screwed in a predetermined position of the valve rod 7 by screwing the convex portion 18a in a horizontal direction, and thereby the locking ring 1 is fixed.
8 is fixed to the outer periphery of the valve rod 7. Therefore, by removing the fixing screw 19, the locking ring 18 is removed.
Can be removed from the valve stem 7.

On the other hand, a cylindrical bottom case 21 is attached to the outside of the valve case 2 facing the bonnet 6 by welding in the same manner as in the case of the bonnet 6 described above. When the bottom case 21 is fixed, as in the case of attaching the hood 6, as shown in FIG. 2, first, a circular flat portion 2c is formed at a predetermined position of the valve case 2, and the lower valve is formed on the flat portion 2c. If a hole 2d for inserting the rod 22 is formed, and then the upper end of the bottom case 21 is fixed to the flat portion 2c, the upper end surface of the bottom case 21 is adjusted to the outer shape of the valve case 2 in particular. It is not necessary to form a so-called "saddle-shaped" shape, and it is easy to manufacture and can realize strong fixing.

The lower valve stem 22 is rotatably inserted into the bottom case 21, and its inserted end, that is, the upper end, protrudes into the valve case 2 through the hole 2d.
The lower part of the valve body 8 is supported and fixed to this upper end . An annular recess 22a is formed near the lower end of the lower valve stem 22 in the bottom case 21. An O-ring 23 is fitted into the annular recess 22a, and the pressing cap 10 is fastened to the upper end of the bonnet 6. By tightening the presser cap 24 having the same configuration as
The ring 23 is pressed so that the water tightness between the bottom case 21 and the lower valve stem 22 is firmly secured, and the lower valve stem 22 is prevented from falling off.

In the state shown in FIG. 1, the valve element 8 is at a position where the flow path of the valve case 2 is shut off.
The inner flow path is opened to the maximum. When the valve element 8 is in the shut-off position, it is necessary to completely seal the outer peripheral edge of the valve element 8 and the inner peripheral surface of the valve case 2. Using a seat ring 31 made of
The valve seat 2 is fixed to the inner surface of the valve case 2 by cylindrical seat ring retainers 32 and 33. In fixing these seat ring retainers 32, 33 to the inner surface of the valve case 2, the seat ring retainers 32, 33 are inserted into the annular grooves 34, 35 formed in the inner surface of the valve case 2.
Is formed by bulging by bulging.

The butterfly valve 1 according to the present embodiment has the above-described structure. To open and close the valve body 8, for example, an operation lever (not shown) that is detachable on the outer periphery of the valve rod 7 is provided.
By rotating the operation lever around the valve rod 7, the valve body 8 can be opened and closed.

Even if the operating lever is released at a predetermined opening degree, the pressing plate 1 is urged by the coil spring 16.
5 presses the locking ring 18, and the pressed surface of the locking ring 18 is the brake surface 18c whose surface is roughly formed as described above, so that a large frictional force is generated. By the pressing and the frictional force, the rotation of the valve body 8 due to the pressure of the fluid flowing in the valve case 2 is prevented. That is, the opening is maintained as it is. The setting of the frictional force, that is, the setting of the anti-rotation torque is performed by appropriately tightening the adjusting nut 17,
This can be easily achieved by changing the degree of compression of the coil spring 16 by loosening it.

In addition, since the opening of the valve body 8 is maintained in this manner, the opening can be maintained at any position continuously and continuously. Moreover, the structure is extremely simple, and the manufacturing cost can be reduced.

In the above-described embodiment, the brake surface which has been a major factor in generating frictional force is the locking ring 1.
5, the same effect can be obtained by forming it on at least the surface 15c of the presser plate 15 which is in close contact with the locking ring 18, as shown in FIG. If such a braking surface is formed on both surfaces opposing the plate 15 and the locking ring 18, it is possible to obtain a larger frictional force.

In the above embodiment, the small-diameter portion 13a of the support shaft 13 is made to protrude from the pressing plate 15 side. Instead, the support shaft 13 is fixed to the pressing plate 15 side, and the small-diameter portion 13a is fixed. To the substrate 12 (flange 11)
The adjusting nut 17 may be screwed onto the protruding end by projecting to the side.

The valve case 2 of the butterfly valve 1
As described above, the flange 3 and the ball seat 5 are formed at both ends, so that a flexible joint connection with another pipe 41 is possible as shown in FIG. That is, at the connection end of the other pipe body 41, a flange 42 having the same configuration as the flange 3 of the valve case 2 and having a tapered opening is formed.
The O-ring 43 is attached to the recess 4, and the flange 42 of the other tube 41 and the ball seat 5 face each other.
2 and a housing 44 formed of, for example, two half-semicircles from the outside of the ball seat portion 5, and the housing 44 is fastened to a fastening member 45 such as a bolt and a nut.
By simply tightening the housings 44, the joint connection can be easily realized.

The water tightness of the joint portion thus constructed is ensured by an O-ring 43 interposed between the collar portion 42 and the ball seat portion 5 and pressed by both. Until the edge of 42 abuts the inner peripheral wall of housing 44, the joint is flexible. Therefore, it is possible to perform a joint connection that is extremely practicable in addition to good workability at the site.

[0037]

According to the first and second aspects, the opening degree of the valve is continuously and continuously maintained by the urging force of the urging member and the frictional force generated thereby. Further, since the structure is basically constituted by the pressing plate, the locking member, the urging member, and the support member, the structure is simplified and the cost can be reduced.

According to the third aspect, the force for maintaining the opening degree is larger than in the first and second aspects, and the present invention can be applied to a valve having a higher fluid pressure.

According to the fourth aspect, the necessary torque for maintaining the opening can be easily and freely set in accordance with the pressure of the fluid flowing in the valve case.

According to the fifth and sixth aspects, the torque can be set very easily by properly tightening and loosening the adjusting nut.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a butterfly valve incorporating an embodiment of the present invention.

FIG. 2 is an axial longitudinal sectional view of a valve case in the butterfly valve of FIG. 1;

FIG. 3 shows an embodiment of the butterfly valve of FIG.
It is an expanded longitudinal cross-sectional view which shows the example of a structure which gives a non-separable relationship between a valve stem and a bonnet.

FIG. 4 shows an embodiment of the butterfly valve of FIG.
It is a principal part longitudinal cross-sectional view which shows the other example of a structure which makes a valve stem and a bonnet a detachable relationship.

FIG. 5 is a perspective view showing an outline of a pressing plate used in an embodiment of the butterfly valve of FIG. 1;

FIG. 6 is a plan view of an embodiment of the butterfly valve of FIG. 1;

FIG. 7 is a perspective view showing an outline of a locking ring used in the embodiment of the butterfly valve of FIG. 1 as viewed from obliquely below.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Butterfly valve 2 Valve case 6 Bonnet 7 Valve rod 8 Valve body 11 Flange 13 Support shaft 13a Small diameter part 15 Press plate 15c Braking surface 16 Coil spring 17 Adjustment nut 18 Locking ring 22 Lower valve rod

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) F16K 35/00-35/16 F16K 1/16-1/226 F16K 5/00

Claims (6)

(57) [Claims] 1. A bonnet whose one end is mounted orthogonally to the outside of a tubular valve case, a valve stem mounted inside the bonnet so as to be rotatable around the axis of the bonnet, A valve attached to a rod and having a valve element capable of shutting off a flow path in a valve case by rotation of the valve rod, a mechanism for maintaining an opening degree of the valve element; A fixing member having a brake surface on the valve case side surface is fixed to the outer periphery of the valve rod protruding from the other end of the bonnet while fixing the support member, and is pressed against the locking member from the bonnet side. Press plate,
A valve member is provided so as to be slidable in the axial direction of the valve stem, and an urging member for urging the pressing plate toward the locking member is interposed between the pressing plate and the supporting member. The mechanism for maintaining the opening of the valve. 2. A bonnet whose one end is orthogonally mounted on the outside of a tubular valve case; a valve stem mounted in the bonnet so as to be rotatable around the axis of the bonnet; A valve attached to a rod and having a valve element capable of shutting off a flow path in a valve case by rotation of the valve rod, a mechanism for maintaining an opening degree of the valve element; The support member is fixed, and a locking member is fixed to the outer periphery of the valve rod protruding from the other end of the bonnet, and a pressing plate pressed from the bonnet side against the locking member is slid in the axial direction of the valve rod. Provided to be movable,
A brake surface is provided on a surface of the pressing plate on the locking member side, and an urging member for urging the pressing plate toward the locking member is interposed between the pressing plate and the support member. Characteristic, valve opening retention mechanism. 3. A bonnet whose one end is mounted orthogonally to the outside of a tubular valve case, a valve stem mounted in the bonnet so as to be rotatable around the axis of the bonnet, and A valve attached to a rod and having a valve element capable of shutting off a flow path in a valve case by rotation of the valve rod, a mechanism for maintaining an opening degree of the valve element; A fixing member having a brake surface on the valve case side surface is fixed to the outer periphery of the valve rod protruding from the other end of the bonnet while fixing the support member, and is pressed against the locking member from the bonnet side. Press plate,
Provided so as to be slidable in the axial direction of the valve stem, providing a brake surface on the surface of the pressing plate on the side of the locking member, further comprising an urging member for urging the pressing plate toward the locking member, Characterized by being interposed between the pressing plate and the support member,
Valve opening retention mechanism. 4. The valve opening holding mechanism according to claim 1, wherein the urging force of the urging member is configured to be adjustable. 5. A biasing member is constituted by a coil spring, and further includes a support shaft having one end fixed to the support member and the other end projecting through the pressing plate. 4. The valve opening holding mechanism according to claim 1, wherein a coil spring is arranged, and an adjusting nut is screwed to a protruding end of the support shaft. 6. The biasing member is formed by a coil spring. One end of the biasing member is fixed to the pressing plate side, and the other end of the biasing member extends around a support shaft configured to project through the support member. 4. The valve opening holding mechanism according to claim 1, wherein a spring is provided, and an adjusting nut is screwed to a protruding end of the support shaft.