JP3376325B2 - 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 valve device improved to improve seal durability and reduce operating force when the valve is opened. .

[0002]

2. Description of the Related Art Conventional butterfly valves generally use rubber for their valve seats, and such a butterfly valve is usually unsuitable for use in a flow path through which a high-temperature, high-pressure fluid flows. Therefore, a metal valve seat has come to be used for a butterfly valve used under high temperature and high pressure conditions. 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 valve shaft is closed by eccentric the rotational axis of the valve body from the central axis of the flow path. Among them, a so-called tilting type is known in which a sealing pressure is applied to the sloped valve seat surface to maintain airtightness.

[0003]

Particularly in the case of a butterfly valve having a metal valve seat, it is necessary to surely seat the valve element at a predetermined position of the valve seat in order to secure the sealing effect at the valve seat. Therefore, it is necessary to make the machining accuracy of the valve body and the valve seat extremely high. Specifically, in a valve seat that uses a metal O-ring, when the valve is closed, the seal portion on the outer circumference of the valve body must be in uniform contact with the valve seat of the metal O-ring. It was necessary to manufacture the both with high precision, paying attention to the positional relationship between the body and the metal O-ring.

Further, in a tilting type butterfly valve, the contact between the valve body and the valve seat should be made only at the fully closing point by design, but in reality, the fitting of the rotary shaft of the valve body described above is performed. Since the joint part is loosened and so-called backlash occurs, the valve body and the valve seat always rub against each other when the valve opening is started. Further, since the rotating shaft is eccentric, the pressure imbalance acting on the valve body when the valve is closed is large. From the above, the tilting type butterfly valve may be difficult to open due to an excessive opening torque after it is fully closed, and is particularly unsuitable for sealing high-pressure fluid.

Therefore, according to the present invention, it is possible to maintain the seal durability of the valve seat high for a long period of time without requiring a highly accurate and difficult work to machine the valve seat, and to open the valve. It is an object of the present invention to provide a valve device capable of reducing the operating force at the time.

[0006]

In order to achieve the above object, the present invention provides a valve box defining a fluid passage therein, a valve seat formed in the fluid passage, and the fluid passage selectively. A valve element that is supported in the valve seat so that it can be engaged and disengaged with respect to the valve seat so as to be blocked and opened, and a valve body that penetrates the valve box and enters the fluid passage to support the valve element. In a valve device having a rotation shaft, the valve device, which is provided between the valve body and the rotation shaft, engages with the valve seat to separate from the valve seat, and separates from the valve seat. In order to engage the valve body with the valve seat, the rotary shaft is rotated in response to the rotation of the rotary shaft at a predetermined angular position, so that the rotary motion of the rotary shaft is controlled by the valve. A motion conversion mechanism for converting the motion of the body into a substantially linear motion, wherein the motion conversion mechanism is a cam provided on the rotation shaft. And a cam surface that is disposed between the cam device and the valve body to transmit the motion of the cam device to the valve body, and has a cam surface that engages with the cam device, and is integral with the valve body. A motion transmitting member that moves in a vertical direction, and a cylindrical portion that is attached to the valve box and rotatably supports the motion transmitting member, and the cylindrical portion includes the motion transmitting member substantially in the axial direction of the valve seat. There are a movement converting member which is partially penetrate and exit possible cutout formed, the exercise Den
The reaching member is a tubular member, and the cam surface is formed on the inner peripheral surface.
And a flat surface that enters and exits the notch on the outer peripheral surface
And an arcuate curved surface having a diameter D are formed,
The inner peripheral surface of the cylindrical portion of the material has an arc-shaped bend of the diameter D.
The surface and the valve seat of the motion transmitting member substantially along the axial direction.
A pair of parallel planes are formed to allow linear movement.
At least the curved surface of the outer peripheral surface of the motion transmitting member
Some are notches of the motion conversion member when the valve body is fully closed.
Formed on the opposite side of the center of rotation of the motion transmitting member
Has been done .

A plurality of the motion converting mechanisms may be provided at intervals along the longitudinal direction of the rotating shaft.

Also, preferably, the motion conversion member is
The inner peripheral surface of the cylindrical portion is at least larger than the diameter D.
A pair of parallel planes are formed at regular intervals.
It

A boss portion for supporting the motion transmitting member is formed on the valve body, and a partial convex portion is formed on one of the boss portion and the motion converting member, and on the other. A partial concave portion that engages with the partial convex portion is formed,
The surface defining the partial convex portion and the surface defining the partial concave portion may be at least a stopper surface serving as a valve closing stopper or a fully closing stopper.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention, that is, an embodiment will be described in detail with reference to the accompanying drawings.
In the drawings, the same reference numerals indicate the same or corresponding parts. In the following description, regarding the direction, the right side of the paper of FIG. 1 is the “front side”, the left side of the paper is the “rear side”, the upper side with respect to the central axis O2 in FIG. 1 is the “upper side”, and the lower side is the “lower side”. , The front side of the paper surface of FIG. 1 is the “left side”, and the back side of the paper surface is the “right side”.

FIG. 1 is a vertical cross-sectional view of the valve device of this embodiment in a fully closed state. 2 is a cross section taken along line XX of FIG. 1, and FIGS. 3 and 4 are views corresponding to FIG. 2 showing a state in the middle of valve opening and a fully opened state, respectively. The valve device of the present embodiment mainly includes a valve box 1, a bonnet 20, a valve body 3,
It is composed of a rod 4 and a drive unit 21.

The valve box 1 is a substantially cylindrical member having a central axis O2 and has a fluid passage 1a defined therein. The flow of the fluid in the fluid passage 1a is as shown by an arrow with a reference symbol R in FIG.
From front to back. A valve box 1 defining a fluid passage 1a
On the rear side of the inner surface of the seat, a seat ring 2 which is screwed and partially welded to the valve box 1 is attached. The bonnet 20 is
It is fixed to a bolt inserted in the upper hole 1d of the valve box 1. An annular valve seat surface 12 is formed on the seat ring 2, and the above-described central axis O2 coincides with the axis of the valve seat surface 12.

The valve body 3 is rotatably arranged in the valve box 1, and a conical valve seat surface 11 is formed on the rear peripheral surface of the valve body 3. When the valve body 3 is fully closed, the valve seat surface 11 is, as shown in FIGS. 1 and 2, the valve seat surface 12 described above.
To shut off the fluid passage 1a. Since the valve seat surface 11 is rigidly made of metal or the like, it can be maintained in a suitable shape so as to exert a sealing function by a valve seat repair method in a general valve. Also, the valve seat surfaces 11 and 1
2 may have a frustoconical shape similar to that of an ordinary target valve,
A spherical shape can exert a higher sealing effect. As shown in FIG. 1, the front portion of the valve body 3 is close to the wall portion 1c that defines the fluid passage 1a in the valve box 1 and is symmetrically arranged with respect to the central axis O2, one by one, respectively. A total of two boss portions 9 are formed. The valve body 3 has a boss portion 9
Disc bush (motion transmission member) which will be described in detail later
It is supported by a rod (rotating shaft) 4 via 10.
Further, as shown in FIG. 7, stopper surfaces 9b and 9c are formed on the end surface of the boss portion 9, and stopper surfaces 6g and 6f are formed on the bush 6 side that abuts on the stopper surface.

The rod 4 penetrates both boss portions 9 and extends in the vertical direction in FIG. 1, and is supported by the valve housing 1 via a bush (motion converting member) 6 which will be described in detail later.
The upper end of the rod 4 extends upward through the valve box 1 and is connected to a normal drive device 21 arranged as shown. A key groove 4a having a predetermined size is formed on the peripheral surface of the rod 4 surrounded by the bosses 9. As can be seen from FIGS. 1 and 2, the key grooves 4a are formed at two positions which are separated by approximately 180 degrees in the circumferential direction and two positions which are separated in the rod axial direction, for a total of four positions. Each keyway 4a
A slide key (cam device) 5 is fitted in the.
The slide key 5 is in contact with the disc bush 10 as will be described later in detail.

Next, the motion converting mechanism will be described. The motion conversion mechanism of this embodiment is a slide key (cam device).
5, a disk bush (motion transmitting member) 10, and a bush (motion converting member) 6. FIGS. 5A to 5C are views showing the keyed rod 4, the disc bush 10, and the bush 6 as a single body. Figure 6
(A) to (d) of FIG. 1 are cross-sectional views taken along the line Y-Y of FIG. 1 for each open / closed state of the valve. Disk bush 10
Is disposed between the boss 9 and the rod 4, and is fixed to the boss 9 so as to operate integrally with the valve body 3.

The outer shape of the disk bush 10 is a curved surface S1 having a radius of curvature D / 2 formed on the front side portion, a curved surface S2 having a radius of curvature D / 2 formed on the rear side portion, and curved surfaces S1 and S.
It is composed of two sets of two planes S3 and S4 connecting the two. Further, the disc bush 10 has a portion 10k on the one end side extending in the axial direction inserted into the boss portion 9, and a hole 13 through which the rod 4 penetrates is provided in the axial center portion.
The hole 13 is defined by arcuate cam surfaces 10a to 10g. These cam surfaces 10a to 10g collaborate with the cam convex portions (cam surfaces) 10h to 10j and come into contact with the slide key 5 fitted to the rod 4 and predetermined to the valve body 3 as described later in operation. Cause the movement of. Also, the cam surface 1
The shapes of 0a to 10g and the cam convex portions 10h to 10j are designed so that the slide key 5 and the disc bush 10 are not completely separated from each other at any angle during the rotation of the rod 4. As a result, it is possible to prevent rattling of the valve element 3 during the opening / closing operation of the valve device.

As can be seen from FIGS. 1, 5 and 7, the bush 6 has a main body portion 6a having a rod penetrating hole 15 fixed between the bonnet 20 and the rod 4, and an outer peripheral side of the disc bush 10. And a cylindrical portion 6b whose inner diameter is approximately D as described above. Cylindrical part 6b
Surround the disk bush 10 and rotatably support the disk bush 10 (see FIG. 6). A notch 6c having a chord length H is formed in an arc shape in the rear portion of the cylindrical portion 6b.

Next, the operation of the valve device of this embodiment will be described. FIG. 2 shows the valve device when fully closed.
Further, FIG. 6A shows the relationship between the slide key 5 and the motion conversion mechanism when fully closed. At the time of fully closing, as shown in FIG. 6A, the rear slide key 5b of the slide keys 5 contacts the cam surface 10d so as to push the disc bush 10 rearward, and the front slide key 5a. Is in contact with the cam surface 10a. For this reason, the rear end edge of the disk bush 10 on the plane S3 is provided with the notch 6c of the bush 6.
The curved surface S1 of the disc bush 10 is separated from the inner peripheral surface of the bush 6 by the protrusion of L mm inward along the central axis O2, and a gap 16 is formed between the curved surface S1 and the inner peripheral surface. On the front side surface of the valve element 3, the fluid pressure P1 (FIG. 1) on the upstream side of the valve element 3 in the flow direction R acts in the direction of the seat ring 2. By this pressure P1,
The valve seat surface 11 of the valve body 3 is pressure-bonded to the valve seat surface 12 of the seat ring 2, and the flow of the fluid passage 1 a that crosses the valve body 3 is blocked. Further, at this time, the stopper surface 9b formed on the boss portion 9 of the valve body 3 is separated from the stopper surface 6g provided on the end surface of the bush 6 by Lmm (see FIG. 2).

The opening operation of the valve body 3 from the above fully closed state will be described. When the drive device 21 is actuated to open the valve body 3, the rod 4 moves in the direction indicated by the arrow Q in FIGS. 2 and 6 (a) in the direction of the longitudinal axis O1 of the rod 4.
Rotate around. Along with this rotation, the slide key 5 attached to the rod 4 also rotates in the direction of arrow Q.
At this time, the front slide key 5a is formed on a cam surface such that the inner peripheral surface of the disk bush gradually decreases from the arc surface 10a to the convex portion 10h to the longitudinal axis O1. Rotate while pressing. Therefore, the disc bush 10 slides in the notch 6c and the cylindrical portion 6b in the frontward direction along the central axis O2. However, the plane S3 of the disk bush 10 has a notch 6
As long as the disc bush 10 is rotating, the plane S3 of the disc bush 10 is caught by the end face 6d of the cylindrical portion 6b defining the notch 6c, so that the disc bush 10 is kept in the rod 4 and the slide key 5. It never rotates together with. Further, the disc bush 10 is in a state of being moved rearward in the bush 6 by L mm in the fully closed state, and concentrically enters the cylindrical portion 6b in the rotating state of the valve body 3, so that the disc having the diameter D is discriminated. A pair of parallel surfaces 6h positioned parallel to each other are provided inside the cylindrical portion 6b so that the bush 10 can be translated in the front-rear direction inside the cylindrical portion 6b. The distance K between the pair of parallel surfaces 6h is slightly larger than the diameter D.

When the disc bush 10 moves to the front side as described above, the valve body 3 integrally connected to the disc bush 10 also moves to the front side in parallel with the central axis O2. As a result, the valve seat surface 11 of the valve element 3 is separated from the valve seat surface 12 of the seat ring 2, and the pressure P1 acting on the front side surface of the valve element 3 is increased.
Are released to the rear side of the valve body 3.

As described above, since the valve body 3 is prevented from rotating while the rod 4 is rotated about 30 ° in this embodiment from the fully closed state, the rotational movement of the rod 4 is translated by the motion converting mechanism. It is converted into motion and transmitted to the valve element 3, and the valve element 3 surely moves forward. It should be noted that this angle is not a critical value and it depends on the shape of the cam surface, slide key, etc.
It can be set to various values of 0 ° or more or 30 ° or less. Further, the linear movement of the valve element also changes from a linear shape to an arc shape according to the shape of the cam surface, slide key, etc., but since the movement distance (Lmm) is short, it can be considered to be substantially linear. . Further, especially when the valve is opened, it is necessary to overcome the fluid pressure acting on the valve body to open the valve body, so that a large force can be applied to the valve body via the motion conversion mechanism.
It is advisable to design the shape of the cam surface, slide key, etc.

The forward movement of the disc bush 10 and the valve body 3 described above continues while the rod 4 rotates about 30 ° in the direction of arrow Q from the fully closed state. That is, the rod 4 is about 3
When rotated by 0 °, the valve body 3 moves to the front side from the state of FIG. 2 by Lm.
After moving by m, the stopper surface 9b of the valve body 3 contacts the stopper surface 6g of the bush 6 as shown in FIG. At the same time, the disc bush 10 moves Lmm from the state of FIG. 6A to the front side, and the curved surface S1 of the disc bush 10 contacts the inner peripheral surface of the cylindrical portion 6b as shown in FIG. 6B. . As a result, the plane S3 of the disk bush 10 is L
End face 6d that moves forward by mm to define notch 6c
Since it is pulled inward from the notch 6c, it is disengaged from the engagement with the notch 6c. For this reason, in the bush 6, the disc bush 10 is fitted concentrically with the bush 6, and the disc bush 10 does not get caught in the inner peripheral surface of the disc portion 6b by the concavo-convex of the disc bush 10.
It can rotate in b. Further, with respect to the slide key 5, the front slide key 5a is in a state of being caught by the convex portion 10h, and the rear slide key 5b is in a state of being fitted exactly into the cam surface 10e [see (b) of FIG. 6]. .

When the rod 4 is further rotated in the direction of the arrow Q after each part of the valve device is in the state shown in FIGS. 3 and 6B, the rotational force of the rod 4 causes the slide key 5 to move. The torque is transmitted to the disc bush 10 as it is as a rotational force. That is, as described above, the front slide key 5a is caught by the convex portion 10h, the slide key 5b is further fitted in the cam surface 10e, and the flat surface S3 is cut out.
Since it is disengaged from c, the disc bush 10 rotates together with the rod 4 in the bush 6 [see (c) of FIG. 6], and the valve body 3 integrally connected to the disc bush 10 also becomes a rod. Spinning with 4 and finally,
The fully opened state shown in FIG. 4 and FIG.

As described above, after the rod 4 is rotated from the fully closed state by about 30 ° in this embodiment, the valve body 3 is rotated about the central axis O.
It cannot move linearly along 2, and the rotational force of the rod 4 is transmitted as it is to the valve body 3 by the motion conversion mechanism, so that the valve body 3 reliably rotates in the valve opening direction.

Next, the case where the valve body 3 is closed from the fully open state will be described. From the state shown in FIGS. 4 and 6D, when the rod 4 rotates in the direction opposite to the arrow Q,
The rear slide key 5b fitted to the cam surface 10e has the convex portion 1
The disk bush 10 rotates in the bush 6 in the same direction as the rod 4 by being caught by 0i. As a result, the valve body 3 integrally connected to the disc bush 10 also rotates in the same direction as the rod 4 (valve closing direction). The motion conversion mechanism
In the state of FIG. 6 (c) through the state of FIG. 6 (c), the angular position of the plane S3 of the disk bush 10 with respect to the notch 6c of the bush 6 is aligned, and both are linearly aligned. As shown, the stopper surface 9b provided on the valve body 3 contacts the stopper surface 6g on the bush 6 side.
After this contact, when the rod 4 further rotates in the direction opposite to the arrow Q, the valve body 3 is prevented from rotating by the stopper surfaces 9b and 6g, so that the protrusion 10i is pushed by the rear slide key 5b. The bush 10 slides rearward through the notch 6c along the central axis O2. As a result, the valve body 3 connected to the disc bush 10 also moves rearward in parallel with the central axis O2. The valve body 3 is Lmm from the state of FIG.
Upon rearward movement, the valve seat surface 11 is in tight sealing engagement with the valve seat surface 12 and the valve device is fully closed.

In the valve device of this embodiment described above, when the valve body 3 opens from the fully closed state, the valve seat surface 1
Since it is separated from the seat ring 2 in parallel with the central axis O2 of the valve 2, the sliding between the valve body 3 and the valve seat surfaces 11 and 12 of the seat ring 2 does not substantially occur. Therefore, the valve seat surface 1
Wear of Nos. 1 and 12 is reduced, and excellent seal durability can be maintained for a long period of time, and frictional resistance due to sliding is reduced, so that the valve body operating force can be made extremely light. Become.

When the valve is closed, the valve body 3 has the valve seat surface 1
Since it moves in parallel with the central axis O2 of 2 to engage with the seat ring 2 to seal the fluid pressure, an extremely high sealing effect can be obtained.

The structure of the stopper function in the above-described embodiment will be described in detail with reference to FIG.
As shown, the bush 6 is formed with a partial convex portion 6e that forms a partial arc, while the boss portion 9 of the valve body 3 is a portion that is combined with the partial convex portion 6e. Partial recesses 9a that form a regular arc are formed. The partial convex portion 6e is defined by the stopper surfaces 6f and g so as to protrude from the axial end surface of the cylindrical portion 6b of the bush 6, while the partial concave portion 9a is defined by the axial end surface of the boss portion 9. Is defined by the stopper surfaces 9b and 9c. According to this structure, the partial convex portion 6e and the partial concave portion 9
As shown in (a) of FIG. 8 in which a is combined, the stopper surface 9b of the partial concave portion 9a and the stopper surface 6g of the partial convex portion 6e engage with each other to rotate the valve body 3 in the valve closing direction. A function as a specified valve closing stopper is obtained, and
As shown in FIG. 8B, the function as a fully open stopper in which the fully open position of the valve body 3 is defined by the engagement of the stopper surface 9c of the partial concave portion 9a and the stopper surface 6f of the partial convex portion 6e. Can also be obtained.

[0029]

As described above, according to the valve device of the present invention, the sliding between the valve seat surfaces is substantially eliminated, so that the wear of the valve seat can be prevented and the conventional friction during sliding can be prevented. The operating force for operating the valve body against the resistance is not required, and the opening / closing operation of the valve body becomes extremely light.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a valve device according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing the valve device in a fully closed state along line XX in FIG.

FIG. 3 is a cross-sectional view showing a valve device in the middle of valve opening or valve closing, taken along line XX in FIG.

FIG. 4 is a cross-sectional view showing the valve device in a fully opened state along line XX in FIG. 1.

5 (a) to (c) are cross-sectional views each showing a rod, a disc bush, a washer, and a bush of the valve device of the present embodiment as a single unit.

6A to 6D are cross-sectional views showing different opening and closing processes of the valve device along line YY of FIG. 1 for explaining the motion conversion mechanism of the valve device of the present embodiment. is there.

FIG. 7A is a perspective view of a bush in which a partial convex portion is formed, and FIG. 7B is a perspective view of a valve body in which a partial concave portion is formed in a boss portion.

8 is a diagram relating to a combination of the bush and the boss portion of the valve body shown in FIG. 7, (a) showing the state of (b) of FIG. 6, and (b) of FIG. It is a figure which shows the state of (d).

[Explanation of symbols]

1 valve box, 1a fluid passage, 2 seat ring, 3 valve body, 4 rod (rotating shaft), 5, 5a, 5b slide key (cam device), 6 bush (motion converting member), 6
c Notch, 10 disk bush (motion transmission member),
10a to 10j Cam surface, 11 and 12 Valve seat surface.

Front page continued (72) Inventor Naotake Tsuboi No. 14 Nakamachi, Moji-ku, Kitakyushu, Fukuoka Prefecture Okano Valve Manufacturing Co., Ltd. (72) Yukio Imoto No. 14 Nakamachi, Kitakyushu, Kitakyushu, Fukuoka Okano Valve Manufacturing Co., Ltd. (56) Reference JP 10-238637 (JP, A) JP 63-293366 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) F16K 1 / 00

Claims (4)

(57) [Claims] 1. A valve box (1) defining a fluid passage therein.
A valve seat (2) formed in the fluid passage, and a valve seat supported in the valve box so as to be engageable with and disengageable from the valve seat so as to selectively block and open the fluid passage. A valve device comprising a valve body (3) and a rotary shaft (4) which penetrates the valve box and enters the fluid passage to support the valve body, the valve device comprising: And rotating the rotating shaft to disengage the valve body engaged with the valve seat from the valve seat and to engage the valve body disengaged from the valve seat with the valve seat. In doing so, a motion conversion mechanism (5, 6, 6) for converting the rotational motion of the rotary shaft into a substantially linear motion of the valve body in response to the rotation of the rotary shaft at a predetermined angular position.
10), wherein the motion conversion mechanism transmits the motion of the cam device to the valve body between the cam device (5) provided on the rotating shaft and the cam device and the valve body. A motion transmitting member (10) which is provided and has a cam surface that engages with the cam device, and which moves integrally with the valve body; and a motion transmitting member that is attached to the valve box and can rotate the motion transmitting member. A motion converting member (6) having a supporting cylindrical portion, and a notch through which the motion transmitting member can partially enter and withdraw in the axial direction of the valve seat. with which it said movement transmission member (10) is a tubular member, the inner peripheral surface
The cam surface (10a to 10g) is formed and the outer circumference
Plane (S3, S4) that enters and exits the notch on the surface
And an arcuate curved surface (S1, S2) having a diameter D is formed,
Inner peripheral surface of the cylindrical portion (6b) of the motion conversion member (6)
Of the arcuate curved surface of the diameter D and the motion transmitting member.
Permits linear movement of the valve seat approximately along the axial direction
A pair of parallel surfaces are formed , and at least a part of the curved surface of the outer peripheral surface of the motion transmitting member.
(S1) is the switching of the motion conversion member when the valve body is fully closed.
The rotation center of the motion transmitting member is sandwiched between the notches (6c).
The valve device is formed on the opposite side . 2. The valve device according to claim 1, wherein a plurality of the motion conversion mechanisms are provided at intervals along the longitudinal direction of the rotating shaft. 3. The cylindrical portion of the motion conversion member (6)
The inner peripheral surface of (6b) is at least larger than the diameter D.
Formed a pair of parallel planes (6h) that are spaced apart from each other
The valve device according to claim 1 or 2, which is characterized by being provided. 4. A boss portion that supports the motion transmitting member is formed on the valve body, and a partial convex portion is formed on one of the boss portion and the motion converting member, and on the other. A partial concave portion that engages with the partial convex portion is formed, and a surface that defines the partial convex portion and a surface that defines the partial concave portion are at least stopper surfaces for a valve closing stopper or a fully closing stopper. The valve device according to any one of claims 1 to 3, characterized in that.