JP2834434B2 - Valve device - 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 device such as a butterfly valve, and more particularly to a technique for improving the seal durability.

[0002]

2. Description of the Related Art A butterfly valve is often used in place of a gate valve because a projected area of a valve element in a flow passage is axisymmetric and flow resistance is small. Conventional general butterfly valves often use rubber for a valve seat, and are not suitable for use in a flow path through which a high-temperature and high-pressure fluid flows. For this reason,
Butterfly valves using metal for the valve seat have come to be used. As a butterfly valve having a metal valve seat,
A metal O-ring is used as a sealing material in the valve seat portion, or a sealing pressure is applied to the gradient valve seat surface during the valve closing state by eccentrically rotating the rotation axis of the valve body from the center axis of the flow path. There is a so-called tilting type that maintains airtightness or liquid tightness.

[0003]

As described above, in the butterfly valve having a metal valve seat, the valve body is securely seated at a predetermined position of the valve seat in order to obtain an air-tight or liquid-tight effect at the valve seat. Therefore, the machining accuracy of the valve body and the valve seat needs to be extremely high. For example,
In a valve seat using a metal O-ring, when the valve is closed, the outer periphery of the valve body must uniformly contact the metal O-ring, that is, the inner diameter surface of the valve seat. For this purpose, the positional relationship between the valve body and the metal O-ring is required. It is necessary to manufacture with high precision while keeping in mind.

In the tilting type, the contact between the valve body and the valve seat should be only at the fully closed point by design.
In practice, play occurs in the fitting of the rotating shaft, so that the valve body and the valve seat always rub at the beginning of opening. Also,
Since the rotating shaft is eccentric, the imbalance in pressure acting on the valve body when fully closed is large. As described above, the tilting type has an excessive opening torque from the fully closed state and may not be easily opened, and is not particularly suitable for sealing a high-pressure fluid.
Accordingly, the present invention provides a butterfly valve that allows the valve seat to maintain excellent sealing durability over a long period of time without requiring sophisticated and difficult operations for machining the valve seat.

[0005]

To achieve the above object, a valve device according to the present invention comprises a valve box having a fluid passage and a valve seat therein, and a valve element rotatably provided in the valve box. A valve element supporting shaft for supporting the valve element, wherein the axis of the portion of the valve element supporting shaft that supports the valve element is moved from the fully closed state to the axis of the valve seat with the start of the valve opening operation. Eccentric from the center of rotation of the valve body support shaft so as to be separated from the valve seat substantially along the direction, and the fluid passage is provided with the valve body during a valve closing operation.
Abuts the valve body toward the fully closed state,
In the valve closing direction so that the valve body is moved substantially along the
A fully closed stopper is provided to stop the rotation
You.

Further, in the valve device according to the present invention, the valve
A recess is formed in a portion of the body support shaft that supports the valve body.
The valve body is supported by the valve body by elastic force.
Before being biased in the direction of contact with the portion of the shaft that supports the valve
A convex member is provided which is engageable with the concave portion.
The convex member is located rearward during the valve opening operation, and is formed by the elastic force.
Rear surface extending in a direction substantially parallel to the biasing direction of the convex member
And a tip surface extending in a direction substantially perpendicular to the biasing direction.
When the convex member engages with the concave portion, the valve
The valve opening direction torque of the body support shaft is transmitted through the rear surface.
And the valve closing direction torque of the valve body support shaft is transmitted through the front end surface.
The valve element is supported by the valve element support
It is characterized in that it rotates integrally with the shaft .

In the valve device having the above-described structure, when the valve body support shaft rotates in the opening direction, the portion of the valve body support shaft that supports the valve body has its axis aligned with the rotation of the valve body support shaft. Performs eccentric rotation that moves in an arc around the center. Thereby, the valve element moves so as to be separated from the valve seat substantially along the axial direction of the valve seat. Further, when the valve element support shaft rotates and the convex member engages with the concave part by elastic force, the valve element is
It rotates integrally with the valve support shaft.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention, that is, embodiments will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals indicate the same or corresponding parts. 1, 2 and 3 are longitudinal sectional views of the butterfly valve 30 of the present embodiment, and FIG. 4 is a sectional view of the butterfly valve 3 of FIG.
0 is a cross-sectional view when cut along the line IV-IV. FIG. 5 shows the shape of the valve seat surface and the eccentric portion 4 described later.
It is a figure explaining eccentricity of the axis of a. In the description of the butterfly valve of the present embodiment, the direction perpendicular to the paper surface of FIG. 1 is defined as “lateral direction” with reference to FIG. ", The upstream side of the fluid passage described later is defined as" front ", and the downstream side is defined as" rearward ", and all the following descriptions will be made.

In FIG. 1, a valve box 1 is a substantially cylindrical member, and has a fluid passage 1a defined therein. The flow direction of the fluid in the fluid passage 1a is indicated by an arrow denoted by a reference symbol R in FIG.

The circular valve body 3 rotatably disposed in the valve box 1 comprises a main body having a spherical valve seat surface 11 and a boss 9. The boss portion 9 is a wall portion 1d which defines the fluid passage 1a in the valve box 1 at a position substantially on the center axis of the fluid passage 1a in the front portion of the valve body main portion, as shown in FIG.
, Two in total, one on each side. Since the valve seat surface 11 is made of a rigid body such as a metal, it is maintained in a suitable shape so as to exhibit a sealing function by a valve seat repairing method in a general valve. The valve 3 is shown in FIG.
As shown in FIG. 2, the rod 4 is rotatably supported by the eccentric portion 4a of the rod 4 which passes through the boss 9 in the lateral direction. A boss portion 9 and an eccentric portion 4 passing through the boss portion 9
As shown in FIGS. 1 to 3, a disc bush 10 is arranged between the disc bush 10 and the disc bush 10. The disc bush 10 is fixed to a hole through which the eccentric portion 4a of the boss 9 passes.

The rod 4 has an eccentric portion 4a and both end portions 4b as shown in FIG. The rod 4 has both ends 4
b, bushes 13, 1 arranged on both sides of the valve box 1
4 is supported. The bushes 13 and 14 are disposed on a line that intersects the center axis of the fluid passage 1a in the lateral direction. One end of the rod 4 is connected to a driving device 19 provided on the side of the valve box 1, and the rod 4 is rotated by the driving device 19. Both ends 4b of rod 4
Has its axis aligned in a straight line, and the axis, that is, the center of rotation, is indicated by reference numeral O1 in FIG.
The axis of the eccentric portion 4a passing through the boss portion 9 is indicated by reference numeral O2 in FIG. That is, the axis O2 of the eccentric portion 4a is located at a distance m below the rotation center O1 of both ends 4b in FIG. 1 in which the valve body 3 is in the fully closed state. Therefore, when the rod 4 rotates, the eccentric part 4a rotates eccentrically with respect to both ends 4b.

A portion of the eccentric portion 4a passing through the boss portion 9 is formed with a notch 4c (see FIG. 1) having a shape engageable with a stepped key 5 described later. How the notch 4c and the stepped key 5 engage during operation of the butterfly valve 30 will be described later. In FIG. 1 in which the valve body 3 is in a fully closed state, a stepped key 5 and a spring 6 are accommodated in a cylindrical accommodation portion provided above the boss 9. The stepped key 5 is provided so as to penetrate the boss portion 9 and the disc bush 10 and contact the eccentric portion 4a. One end of a spring 6 is in contact with the stepped key 5. The other end of the spring 6 is in contact with the cap 7. The stepped key 5 and the spring 6 are pressed by a screw-type cap 7 so as not to protrude from the accommodation portion. In addition, stepped key 5
Are biased toward the eccentric portion 4a by the elastic force of the spring 6. A bolt 20 passes through the cap 7. One end of the bolt 20 protrudes from the surface of the cap 7 on the eccentric portion 4a side. On the surface of the cap 7 opposite to the eccentric portion 4a, a nut 21 screwed with the other end of the bolt 20 is provided. As will be described later, the bolt 20 restricts the movement of the stepped key 5 to optimize the amount of retreat of the valve element 3.

FIG. 7 is a longitudinal sectional view of the disc bush 10. As described above, the disc bush 10 is fixedly disposed in the boss portion 9 between the boss portion 9 and the eccentric portion 4a. Disc bush 10 through which the eccentric part 4a passes
The hole 10a is separated from the semicircle A centered on the rotation center O1 indicated by the two-dot chain line in FIG. 7 and the semicircle B centered on the axis O2 indicated by the one-dot chain line in the distance m. It has a cross section of the shape.

As shown in FIG. 1, a closed stopper surface 3a is formed at the upper end of the valve body 3. The closed stopper surface 3a is provided so as to be in contact with a fully closed stopper portion 1b formed on an upper wall defining the fluid passage 1a of the valve box 1.

A seat ring 2 is provided between the valve box 1 and the flange 8 to abut the valve body 3 to seal the fluid in the fluid passage 1a. The seat ring 2 has a front surface in contact with a gasket 16 in a groove formed in the valve box 1, and a rear surface in contact with a flange 8 having a gasket 15. It is sandwiched between. The flange 8 is connected to the valve box 1 by bolts 17. The seat ring 2 is formed with a valve seat surface 12 that contacts the valve seat surface 11 of the valve body 3. The valve seat surface 12, like the valve seat surface 11, is made of a rigid body that may be made of metal or the like.

Referring to FIG. 5, the valve seat surface 11 and the valve seat surface 12 will be described.
Will be described. Valve seat surface 11 and valve seat surface 12
Is an annular portion corresponding to the outer peripheral slope of the truncated hemisphere. The valve seat surface 11 is a convex surface of the outer slope of the truncated hemisphere, which is raised from the outer slope surface of the truncated cone that passes straight through the leading edge and the trailing edge. Depressed from the outer slope of the truncated cone that passes straight through the edge and trailing edge,
The truncated surface of the outer slope of the truncated hemisphere. In the following description, since the gradient of the depression of the valve seat surface 11 and the gradient of the swelling of the valve seat surface 12 are substantially the same, only the valve seat surface 12 will be described as a representative. As shown in FIG. 5, the center of the truncated hemisphere is located at a point where the axis O2 intersects the axis of the fluid passage.
The distance to 2 is the radius of curvature indicated by the reference symbol T.
Since the above point appears in the drawing in the same manner as the axis O2 described above, the reference numeral O2 is also used when indicating the center of curvature of the valve seat surface 12.

Next, the positional relationship between the center of rotation O1 and the center of curvature O2 will be described. In FIG. 5, reference numeral h indicates an annular leading edge of the valve seat surface 12, and reference numeral i indicates the valve seat surface 12.
5 shows the annular trailing edge of the ring. The two-dot chain line e is a line connecting the leading edge h and the center of curvature O2 in the longitudinal section shown in FIG.
An alternate long and short dash line f is an extension of a line connecting the trailing edge i and the center of curvature O2 in the longitudinal section shown in FIG. The center of rotation O1 of the present embodiment is separated from the center of curvature O2 by the distance m as described above, and in addition, a range g sandwiched between the two-dot chain line e and the one-dot chain line f above the center of curvature O2.
It is located at. The rotation center O1 is
It is located on the central axis of the fluid passage shown by the dotted line in FIG. The center axis of the seat ring 2, which is indicated by a three-dot chain line passing through the center of curvature O2 in FIG. 5, is eccentric from the center axis of the fluid passage 1a by a distance m.

Next, the butterfly valve 3 according to the present embodiment
The operation of 0 will be described. FIG. 1 shows a fully closed state of the valve element 3, and a pressure P <b> 1 of a fluid at an upstream portion of the valve element acts on the front surface of the valve element 3 toward the seat ring 2. With this pressure, the valve seat surface 11 of the valve body 3 is pressed against the valve seat surface 12 of the seat ring 2 to seal the fluid. When the valve body 3 is fully closed, the stepped key 5
Is in contact with one end of the bolt 20 described above.
When opening the valve body 3 from the fully closed state, first, the drive unit 19
As a result, the rod 4 rotates around the rotation center O1 in the direction indicated by the arrow Q in FIG. Due to this rotation, the axis O2 of the eccentric portion 4a moves along an arc-shaped trajectory at a fixed distance m from the rotation center O1 in the longitudinal sections shown in FIGS. That is, as shown in FIG. 2, the axis O2 moves forward with respect to the rotation center O1 in the front-rear direction, and moves closer to the rotation center O1 in the up-down direction. Therefore, when the axis O2 of the eccentric portion 4a moves forward from the rotation center O1 by the rotation of the rod 4, the valve element 3 supported by the eccentric portion 4a at the boss 9 also moves forward. Thereby, the valve seat surface 11 of the valve body 3 is separated from the valve seat surface 12 of the seat ring 2 substantially along the axial direction of the seat ring 2 to release the seal on the valve seat surface.
When the eccentric portion 4a starts rotating as described above, the lower part of the stepped key 5 comes into partial contact with the notch 4c, so that the stepped key 5 is eccentric by the elastic force of the spring 6. It moves towards the part 4 a, whereby the upper surface of the stepped key 5 is separated from one end of the bolt 20.

Then, as shown in FIG.
When the rod 4 rotates until it is located at a distance v forward and a distance w below the rotation center O1, the notch 4c of the eccentric portion 4a engages with the stepped key 5 by the elastic force of the spring 6. Combine. As a result, as shown in FIG.
In the rotation in the valve direction, the same level as the rear side of the stepped key 5
The surface 5a substantially parallel to the urging direction of the key 5 is notched.
4c, after which the rod 4 rotates in the valve opening direction.
When the valve is opened, the torque in the valve opening direction is adjusted via the rear surface 5a to the stepped key 5.
Is transmitted to The distance w shown in FIG. 2 between the center of rotation O1 and the axis O2 in the vertical direction is smaller than the distance m shown in FIG. 1 in which the valve body 3 is fully closed.

When the rod 4 is further rotated in the direction of arrow Q from the state shown in FIG. 2, an open stopper surface 18 provided on the front surface of the valve body 3 is provided on the valve box 1 as shown in FIG. The valve body 3 comes into contact with the fully opened stopper 1c and the valve body 3 is fully opened, and the fluid flows from the upstream portion to the downstream portion in the fluid passage 1a. As described above, the butterfly valve 30 utilizes the eccentricity of the eccentric portion 4a with respect to the both end portions 4b, and
Since the valve is opened, the operating force is small. Also,
In the present embodiment, the open stopper surface 18 is the fully open stopper 1c.
Further, the drive unit 19 applies a torque to the rod 4 and the valve opening force by the torque is applied to the stepped key 5, the valve body 3 and the opening stopper surface 18, so that the valve body 3 due to the flow of fluid or the like. Prevention of wobble.

Next, when closing the valve body 3 from the fully open state shown in FIG. 3, the driving machine 19 rotates the rod 4 in the direction of arrow S. The rod 4 rotates around the rotation center O1 with the bush 13 and the bush 14 provided in the valve box 1 as support members. Notch 4c is a stepped key
A tip surface 5b extending in a direction substantially perpendicular to the biasing direction of
Due to the engagement, the eccentric portion 4a of the rod 4 rotates.
And the torque in the valve-opening direction is changed to a stepped key through the tip surface 5a.
5 from the state shown in FIG. 3 to FIG.
Until the state shown in FIG. Then, when the valve element 3 reaches the position shown in FIG.
Since the closing stopper surface 3a contacts the fully closing stopper portion 1b, the valve body 3 does not rotate even if the rod 4 further rotates in the direction of arrow S thereafter. The valve body 3 is provided by the fully closed stopper 1b.
When the rod 4 further rotates in the direction of the arrow S after the stop, the axis O2 moves in an arc around the rotation center O1, and the hole 10a of the disc bush 10 extends as described above. The force acting on the valve body 3 by the movement of 4a is
The direction of the seat ring 2 is suitably changed, and the valve element 3 is retracted so as to approach the seat ring 2. Also, during this time,
The notch 4 c formed in the eccentric part 4 a with the rotation of the rod 4 forms a stepped key 5 against the elastic force of the spring 6.
Is pushed up, the upper surface of the stepped key 5 approaches one end of the bolt 20. Then, as shown in FIG. 1, when the upper surface of the stepped key 5 abuts against one end of the bolt 20, the upward movement of the stepped key 5 is restricted and the eccentric portion 4a
The rotation of the valve body 3 in the direction indicated by the arrow S is also restricted, so that the above-described retraction of the valve body 3 is stopped, and the valve seat surface 11 of the valve body 3 engages with the valve seat surface 12 of the seat ring 2 so that the fluid path The fluid is sealed. It is assumed that the contact between the stepped key 5 and the bolt 20 is adjusted so as to be performed when the valve body 3 is suitably engaged with the seat ring 2. Are screwed as described above, so that the bolts 20 can be turned easily and accurately by turning them. From the above, during the operation of the valve body 3,
Since the valve seat surface 11 of the valve body 3 hardly slides with the valve seat surface 12 of the seat ring 2, there is no need to adjust the positional relationship between the valve body 3 and the seat ring 2 with high accuracy, and special accuracy is achieved. No need for good processing. Further, since the sliding is small as described above, the damage to the valve seat surface is small and the sealing property is maintained for a long period of time. Further, by restricting the movement of the stepped key 5 by the bolt 20, the valve body 3 is prevented from retreating more than necessary for sealing.

The valve case 1, the seat ring 2 and the flange 8 do not have to be separate as shown in FIG. 1, and the seat ring defines a fluid passage in the valve case as shown in FIG. It may be formed as a part of a part.

[0023]

As described above, according to the valve device of the first aspect of the present invention, the axis of the portion of the valve body supporting shaft that supports the valve body is moved along with the start of the valve opening operation. The valve body is eccentric from the center of rotation of the valve body support shaft so that the valve body is separated from the valve seat substantially along the axial direction of the valve seat. Excessive abrasion due to sliding between the valve body and the valve seat is prevented, and high sealing performance is maintained for a long period of time for the valve body and the valve seat, and high-precision machining is not required.

Further, according to the valve device of the present invention , a concave portion is formed in a portion of the valve body support shaft that supports the valve body, and the valve body is supported by the valve body by elastic force. A convex member is provided, which is urged in a direction abutting on a portion of the shaft supporting the valve body and is engageable with the concave portion, and the valve body has the concave portion and the convex member engaged. Sometimes, since the valve body rotates integrally with the valve body support shaft, the valve body rotates in a state separated from the valve seat, so that a high sealing property is maintained for a long time.
And high precision machining is not required
The above-mentioned effect can be more reliably achieved.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a butterfly valve according to an embodiment of the present invention in a fully closed state.

FIG. 2 is a longitudinal sectional view of the butterfly valve of FIG. 1 immediately before fully closing or immediately after opening.

FIG. 3 is a longitudinal sectional view of the butterfly valve of FIG. 1 in a fully closed state.

FIG. 4 is a sectional view of the butterfly valve taken along line IV-IV of FIG. 1;

FIG. 5 is a diagram illustrating the shape of a valve seat surface and the eccentricity of an axis.

6 is a sectional view of the butterfly valve having a seat ring integrated with the valve box, taken along line IV-IV in FIG. 1;

FIG. 7 is a longitudinal sectional view of a disc bush.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Valve box, 1a ... Fluid passage, 1b ... Fully closed stopper part, 2
... seat ring (valve seat), 3 ... valve body, 4 ... rod (valve body support shaft), 4a ... eccentric part (portion supporting the valve body of the valve body support shaft), 4c ... notch (recess), 5: stepped key (convex member), 5a: rear surface, 5b: tip surface, O1: rotation center (center of rotation), O2: axis.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Makoto Okumura 1-14 Nakamachi, Moji-ku, Kitakyushu City, Fukuoka Prefecture Inside Okano Valve Manufacturing Co., Ltd. (72) Koji Tanaka 1-14 Nakamachi, Moji-ku, Kitakyushu-shi, Fukuoka Prefecture Inside Okano Valve Manufacturing Co., Ltd. (72) Takashi Tsuchiya 1-14 Nakamachi, Moji-ku, Kitakyushu-shi, Fukuoka Prefecture Inside Okano Valve Manufacturing Co., Ltd. (56) References JP-A-7-4532 (JP, A) Hei 7-42850 (JP, A) JP-A-63-158367 (JP, A) JP-A-57-161369 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) F16K 1 / 226 F16K 1/34 F16K 1/48

Claims (1)

(57) [Claims] 1. A valve device comprising: a valve box having a fluid passage and a valve seat therein; and a valve element support shaft rotatably provided in the valve box to support a valve element. axis of the portion for supporting the valve body, the total
With the start of the valve-opening operation from the closed state, the valve body is eccentric from the center of rotation of the valve body support shaft so that the valve body is separated from the valve seat substantially along the axial direction of the valve seat. The fluid passage abuts on the valve body during the valve closing operation,
The valve body is moved substantially in the axial direction of the valve seat toward the closed state.
Rotation of the valve body in the valve closing direction so that
A stopper for stopping the valve is provided , a recess is formed in a portion of the valve support shaft that supports the valve, and a recess is formed in the valve, the valve support of the valve support by elastic force. is urged portion and abutting direction for supporting the valve body can be said recess and engaging the convex member is provided, wherein the convex member, the elastic force a backward during opening operation
Rear surface extending in a direction substantially parallel to the urging direction of the convex member
And a tip surface extending in a direction substantially perpendicular to the biasing direction.
And when the convex member is engaged with the concave portion, the valve body support is provided.
The valve opening direction torque of the shaft is transmitted through the rear face and the
The valve closing direction torque of the valve body support shaft is transmitted through the tip surface.
The valve device rotates the valve body integrally with the valve body support shaft.