JPH0237333Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The present invention utilizes a seat ring retainer (seat retainer) that has been conventionally used to hold an annular seat ring in a predetermined position within an annular valve body. This invention relates to a butterfly valve that is held within the valve body by the seat ring itself.

(Prior Art) A conventionally used butterfly valve in which a seat ring is mounted inside a valve body by a seat ring retainer is shown in Fig. 6.
A stepped portion 1a formed on the inner surface of the butterfly valve body 1
An annular seat ring 3 is placed on the side surface of the valve body 2 so as to be in close contact with the circumferential surface of the valve body 2 when the valve is closed, and one side surface (the right side surface in the figure) 3a is opposite to an annular seat ring retainer 4 (in the figure). It is arranged so that it is pressed by the left side) side.

The annular seat ring retainer 4 has a stepped portion 1a on the inner surface of the valve body 1 that the seat ring 3 contacts.
The opposing circumferential surface is brought into contact with the stepped portion 1b formed on the outer side of the valve body 1, and the other open side surface (the right side side in the figure) 4a is brought into contact with the end wall surface 1c of the valve body 1.
The valve body 1 is fitted so as to be substantially flush with the valve body 1 with an appropriate gasket gasket interposed therebetween, and is fixedly attached to the valve body 1 by a hexagon socket head bolt 5.

When the valve is closed, the inner circumferential surface of the seat ring 3 and the outer circumferential surface of the valve body 2 come into contact with each other, thereby sealing the fluid.

(Problem to be solved by the invention) The above-mentioned conventional seat ring holding device (mechanism)
had the following problems:

(i) When machining bolt holes for bolts 5 to solidify valve body 1 and seat ring retainer 4,
Since both the valve body 1 and the retainer 4 must be brought into contact with each other and processed simultaneously, the valve body 1 and the retainer 4 are not compatible.

(ii) When piping the valve, the end wall surface 1c of the valve body 1
When the flanges of the piping are brought into contact with each other and joined (connected) via the gasket packing, the effective tightening allowance of the gasket packing is reduced at the counterbore of the hexagon socket head bolt 5, and therefore the It is more likely that the internal fluid will leak to the outside than the joint.

(iii) Since it is necessary to provide the solid hexagonal bolt holes of the seat ring retainer 4 on the outer periphery of the seat ring mounting step 1a of the valve body 1, the size of the seat ring 3 is limited due to space considerations. If it is desired to increase the size of the seat ring 3 without changing the valve outer diameter, it is necessary to take measures such as reducing the valve inner diameter. This leads to a decrease in the C _V value characteristics, that is, the flow characteristics.

(iv) Since the seat ring 3 is disposed within the valve body 1 via the seat ring retainer 4, it is necessary to provide a means for providing sealing properties at the abutting portion between the retainer 4 and the seat ring 3; The structure becomes complicated.

(v) The number of parts of the seat ring retainer 4 increases.

(vi) The size of the seat ring 3 is reduced by the depth of the retainer 4, and variations in shape etc. are restricted, making it impossible to incorporate multi-purpose functions into the seat ring 3.

The technical objective of the present invention is to solve the above-mentioned problems.

(Means for Solving the Problems) In order to solve the above-mentioned problems of the prior art, the present invention eliminates the use of the conventionally used seat ring retainer. The seat ring is attached to the stepped part formed on the inner surface of the valve body from one end surface of the inner surface of the valve body, and the annular groove provided on the inner circumferential surface of the seat ring attachment part of the valve body and the annular groove provided on the outer circumferential surface of the seat ring are connected in the radial direction. It is equipped with a plurality of movable balls and a member such as a bolt having an inclined surface at the end for moving these balls in the radial direction, and the valve body and the seat ring are connected by the engagement of the annular groove and the balls. It is characterized by solidifying and holding the seat ring in a predetermined position on the inner surface of the valve body.

In practice, it is desirable that the annular groove provided on the inner circumferential surface of the valve body on which the seat ring is attached be formed into a modified rectangular groove having a cross section that is inclined outward.

(Function) Since the present invention is configured as described above,
The balls attached to the outer circumferential surface of the seat ring are completely housed within the seat ring and do not protrude beyond the outer circumference when no member for moving the balls in the radial direction is inserted into the seat ring. .

When fixing the seat ring to the inner circumferential surface of the valve body where the seat ring is attached, the balls are forcibly pushed outward in the radial direction by operating a member that moves the balls in the radial direction. It protrudes further and engages with an annular groove provided on the inner peripheral surface of the valve body. This causes the seat ring to be axially fixed within the valve body via the balls.

Next, when removing the seat ring from the valve body, operate the member that moves the ball radially away from the ball to allow the ball to move radially inward, and then remove the seat ring from the valve body. By pulling it out from the attachment part of the main body, the seat ring is separated from the valve main body.

(Example) Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a cross-sectional view of essential parts of a seat ring holding device (mechanism) for a butterfly valve shown in an embodiment of the present invention, and FIG. 2 is a partially enlarged front view of the seat ring in FIG. , the same reference numerals as those shown in FIG. 6 indicate the same or similar parts.

In the figure, an annular seat ring 13 is formed on the side surface of a step 1a formed on the inner surface of the valve body 1, and has a thin curved portion 13a on the inner circumference so as to come into close contact with the circumferential surface of the valve body 2 when the valve is closed. However, one opposing side surface 13b
The other open side surface 13c is disposed so as to be in substantially the same plane as the end wall surface 1b of the valve body 1.

And the inner peripheral surface 1 of the seat ring mounting part of the valve body 1
c, an annular groove 15 having an inclined surface 15a whose cross section widens toward the outside, that is, toward the end wall surface 1b;
is formed, and the seat ring mounting inner peripheral surface 1
Seat ring 13 facing c with a gap
On the outer peripheral surface 13d of the seat ring 13, shallow small holes 16 extending from the outside in the radial direction to the inside are bored at at least two locations facing the annular groove 15. A tap hole 17 having a diameter smaller than the diameter of the small hole 16 is bored from the other side surface 13c so as to pass through the small hole 16.

Further, a ball 18 such as a steel ball, for example, is mounted in the small hole 16 of the seat ring 13. The diameter of the ball 18 is made larger than the root diameter of the tap hole 17 in order to prevent it from entering the tap hole 17.

On the other hand, a follower set 19 consisting of a bolt with an inclined surface at the end is screwed into the tapped hole 17 from the outside, and by screwing in or loosening the follower set 19,
The ball 18 is configured to move in the radial direction to engage with or disengage from the annular groove 15 on the inner peripheral surface of the valve body.

Next, the effect will be explained.

The ball 18 installed in the small hole 16 of the seat ring 13 is inserted into the small hole 1 as shown in FIG.
Since it is completely housed within the seat ring 6, it does not protrude beyond the outer periphery of the seat ring 13. Seat ring 13 is therefore in an uncoupled state.

When fixing the seat ring 13 to the seat ring mounting inner circumferential surface 1c of the valve body 1, as shown in FIG. The balls 18 are forcibly pushed outward in the radial direction by the and circumferential surfaces, and the balls 18 protrude from the outer circumference of the seat ring 13 and engage with the annular grooves 15 provided on the inner circumferential surface 1c of the valve body. At this time, the ball 18 is pushed outward while moving along the inclined surface 15a of the annular groove 15 toward the valve body (Rx direction in FIG. 5). At this time, the contact point between the ball 18 and the small hole 16 of the retainer is also displaced, but by making the length of the inclined part in the Rx direction larger than the amount of displacement,
The retainer can be pushed towards the valve body. As a result, the retainer 14 is connected to the valve body 1 through the balls 18.
axially consolidated.

Next, when the seat ring 13 is to be removed from the valve body 1, the follower set 19 is loosened and retreated, and the seat ring 13 is pulled out in the direction of the arrow X while the balls 18 are in a state where they can be moved radially inward. As shown in FIG.
5a and the component force Ry of the reaction force R ₁ generated at this time
Accordingly, the ball 18 is accommodated in the small hole 16,
Along with this, the seat ring 13 separates from the valve body 1.

In the above-described embodiment, a structure was described in which the annular groove 15 provided on the inner circumferential surface 1c of the valve body was formed into a modified rectangular cross section with an inclined surface 15a. If the ball 18 is pulled back inward in the radial direction using, for example, the attractive force of a magnet, there is no particular need to provide the inclined surface 15a as described above.

Further, the member for moving the balls 18 outward in the radial direction is constituted by a follower set 19 consisting of a bolt screwed into a tap hole 17 bored in the seat ring 13 and having an inclined surface at the end. As described above, a rotating shaft having a notch with a crescent-shaped cross section perpendicular to the axis in a portion corresponding to the small hole 16 of the seat ring is inserted into the tap hole 17,
It is also possible to move the ball 18 in the small hole 16 that abuts the notch in the radial direction by rotating the rotation shaft through a certain angle (for example, 90 degrees).

(Effect of the invention) As explained above, according to the invention, the seat ring is attached from one end surface of the inner surface of the valve body, and the annular groove provided on the inner peripheral surface of the seat ring attachment part of the valve body and the seat ring By engaging with a plurality of radially movable balls mounted on the outer circumferential surface, the valve body and the seat ring are solidified and the seat ring is held at a predetermined position on the valve body, which makes it possible to The seat ring can be easily attached to and detached from the inner surface of the valve body without providing a seat ring retainer. Therefore, not only the number of parts is reduced, but also the structure is simplified because there is no need to provide sealing means at the abutting portion between the seat ring retainer and the seat ring as in the conventional case.

Furthermore, the size of the seat ring is not affected by the size, depth, etc. of conventional seat ring retainers, so the size, etc. of the seat ring can be freely set.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of essential parts showing an embodiment of the present invention;
Fig. 2 is a partially enlarged front view of the seat ring in Fig. 1, Figs. 3 to 5 are action explanatory views, and Figs.
The figure is a sectional view of a main part showing a conventional example. DESCRIPTION OF SYMBOLS 1... Valve body, 2... Valve body, 13... Seat ring, 15... Annular groove, 15a... Inclined surface, 16
...Small hole, 17...Tap hole, 18...Ball,
19...Follow set.

Claims (1)

[Claims for Utility Model Registration] 1. In a butterfly valve without a seat ring retainer, a seat ring is attached to a step formed on the inner surface of the valve body from one end surface of the inner surface of the valve body, and the seat ring of the valve body An annular groove provided on the inner circumferential surface of the mounting part, a plurality of balls provided on the outer circumferential surface of the seat ring and movable in the radial direction, and a member for moving these balls in the radial direction. A seat ring holding device for a butterfly valve, characterized in that a valve body and a seat ring are solidified by engagement. 2 The member that moves the ball in the radial direction is
The seat ring holding device for a butterfly valve according to claim 1, which is constituted by a bolt that is screwed into one side wall of the seat ring and has an inclined surface at its end. 3. The seat ring holding device for a butterfly valve according to claim 1, wherein the annular groove provided on the seat ring mounting inner circumferential surface of the valve body has a surface whose cross section is inclined outward.