JPH0237332Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention relates to a butterfly valve that has a seat ring and a seat ring retainer (seat retainer) separately, and in particular, the annular seat ring is attached to the inner periphery of the annular valve body. The present invention relates to a seat ring holding device that is held by a seat ring retainer.

(Prior Art) As shown in FIG. 6, a butterfly valve having a separate seat ring and seat ring retainer as described above has a side surface of a stepped portion 1a formed on the inner periphery of a butterfly valve body 1. When the valve is closed, the annular seat ring 3 is brought into close contact with the circumferential surface of the valve body 2, and its one side (the right side in the figure) 3a is connected to the opposite (left side in the figure) side of the annular seat ring retainer 4. It is arranged so that it can be pressed by.

The annular seat ring retainer 4 has a stepped portion 1a on the inner periphery of the valve body 1 that the seat ring 3 comes into contact with.
The opposing circumferential surface is brought into contact with the stepped portion 1b formed on the outside adjacent to the stepped portion 1b, and the other open side surface 4
It is fitted with an appropriate gasket packing interposed so that a is substantially flush with the end wall surface 1c of the valve body 1, and is secured by a hexagon socket head bolt 5.
It is fixed or firmly attached to the valve body 1.

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 flange portions of the piping are brought into contact with each other and connected via the gasket packing, the effective tightening allowance of the gasket packing is reduced at the counterbore portion of the hexagon socket head bolt 5, and therefore , leakage of internal fluid to the outside (leakage)
is likely to induce.

(iii) Since the solid hexagonal bolt holes of the seat ring retainer 4 must be provided 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.

In order to deal with the above-mentioned problems, a device has been devised that does not use the conventional hexagon socket head bolt, as shown in FIG. That is, in FIG. 7, an annular groove 5 is provided on the inner circumferential surface 1d of the seat ring retainer mounting portion of the valve body 1.
An annular groove 6 is also provided on the outer peripheral surface of the seat ring retainer 4 at a position facing the seat ring retainer 4, and a tapped hole 7 located so as to penetrate the bottom of the annular groove 6 opens into the side wall surface of the retainer 4. It is perforated. A ring-shaped spring 8 is disposed to surround the insides of both the annular grooves 5 and 6 so as to straddle the annular grooves 5 and 6.

When attaching the seat ring retainer 4 to the stepped portion 1b of the valve body 1 so as to press the seat ring 3 against the stepped portion 1a of the valve body 1, when a bolt-shaped follower 9 is screwed into the tapped hole 7, the ring spring 8 is The follower 9 is pushed radially outward by the circumferential surface of the follower 9 and moved to a position intermediate between the two annular grooves 5 and 6, as shown. Thereby, the seat retainer 4 is fixed to the inner peripheral surface of the valve body 1 via the ring spring 8,
Accordingly, the seat ring 3 is fixed to the inner surface of the valve body 1.

However, the above-mentioned method also had the following problems.

(i) When the seat ring retainer 4 is installed, both ends of the ring spring 8, that is, both ends of the ring spring 8 when it is stretched out into a band, tend to lift up, making installation somewhat difficult.

(ii) When the fluid used is at a high or low temperature, even if the follower set 9 is loosened, the ring spring 8 will not recover due to high or low temperature brittleness, and therefore the retainer 4 will not separate from the valve body 1.

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

(Means for Solving the Problems) In order to solve the problems of the prior art described above, the present invention provides a butterfly valve that has a seat ring and a seat ring retainer separately. A seat ring retainer is disposed on the inner periphery of the valve body, and a seat ring retainer is attached to one end wall surface of the valve body so as to abut one side of the seat ring on the inner surface of the valve body in order to hold the seat ring in a predetermined position. Attachment: an annular groove provided on the inner circumferential surface of the valve body to which the seat ring retainer is attached, a plurality of balls provided on the outer circumferential surface of the seat ring retainer and movable in the radial direction, and an end section for moving the balls in the radial direction. and a member such as a bolt having an inclined surface, the valve body and the seat ring retainer are solidified by the engagement of the annular groove and the ball, and the seat ring is fixed to the inner surface of the valve body. .

In addition, in implementation, the annular groove provided on the inner circumferential surface of the valve body where the seat ring retainer is attached,
Preferably, the cross section is a modified rectangular groove having an outwardly inclined surface.

(Function) Since the present invention is configured as described above,
The balls installed inside the seat ring retainer are
When the member for moving the balls in the radial direction is not inserted into the retainer, it is completely housed within the retainer, so that it does not protrude beyond the outer periphery of the retainer.

When fixing the seat ring retainer to the inner circumferential surface of the valve body where the retainer is attached, the balls can be moved radially outward by manipulating the member that moves the balls in the radial direction. It protrudes from the outer circumference and engages with an annular groove provided on the inner circumferential surface of the valve body. Thereby, the retainer is axially fixed to the valve body via the balls.

Next, when removing the seat ring retainer from the valve body, operate the member that moves the balls in the radial direction to separate them from the balls so that the balls can be moved inward in the radial direction, and then remove the retainer from the valve body. By pulling it out from the retainer mounting portion, the retainer is removed from the valve body.

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

FIG. 1 is a sectional view of the main parts of a seat ring retainer (mechanism) for a butterfly valve showing an embodiment of the present invention, FIG. 2 is a front view of the seat ring retainer in FIG. 1, and FIG. This is an enlarged view of part A in the figure, and the same reference numerals as those shown in FIGS. 6 and 7 indicate the same or similar parts.

In the figure, an annular seat ring 3 is attached to a stepped portion 1a formed on the inner periphery of the valve body 1 so as to be in close contact with the circumferential surface of the valve body 2 when the valve is closed. The seat ring retainer 14 is arranged so as to be pressed by the opposite side surface of the retainer 14, and the seat ring retainer 14 has a step portion 1b formed on the outside adjacent to the step portion 1a with which the seat ring 3 comes into contact. The valve body 1 is mounted so that its opposite side surface 14b is in contact with the side surface and the other open side surface 14a is approximately flush with the end wall surface 1c of the valve body 1, as compared to the conventional valve body (sixth, 7
There is no difference from the figure).

In this embodiment, an inclined surface 15a is formed on the inner circumferential surface 1d of the seat ring retainer mounting portion of the valve body 1 so that the cross section widens toward the outside, that is, toward the end wall surface 1c.
An annular groove 15 is formed at a position opposite to the annular groove 15 on the outer circumferential surface 14c of the seat ring retainer 14, which faces the retainer mounting inner circumferential surface 1d with a gap. Shallow small holes 16 in two places, going from the outside in the radial direction to the inside.
A tap hole 17 having a root diameter smaller than the diameter of the small hole 16 is formed from one side wall surface 14a of the retainer 14 so as to pass through the small hole 16.

A ball 18, such as a steel ball, is mounted in the small hole 16 of the retainer. The diameter of the ball 18 is normally 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 The valve body is configured to forcibly move in the radial direction to engage with or disengage from the annular groove 15 on the inner circumferential surface of the valve body.

Next, the effect will be explained.

The balls 18 installed in the small holes 16 of the seat ring retainer 14 are completely housed in the small holes 16 when the follower set 19 is not screwed in, as shown in FIG. It does not protrude beyond the outer periphery.

When fixing the seat ring retainer 14 to the inner circumferential surface of the valve body 1 where the retainer is attached, as shown in FIG. The balls 18 are forcibly pushed upward in the radial direction by the circumferential surface, and the balls 18 protrude from the outer circumference of the retainer 14 and engage with the annular grooves 15 provided on the inner circumferential surface of the valve body. As a result, the retainer 14 is axially fixed to the valve body 1 via the balls 18. At this time, by tightening the follower set 19, the ball 18 moves outward along the inclined (tapered) surface 15a of the annular groove 15 of the valve body in the direction of the valve body ( _R being pushed towards 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 portion in the R _X direction larger than the amount of displacement, the retainer 14 can be pressed toward the valve body.

Next, when the seat ring retainer 14 is to be removed from the valve body 1, the follower set 19 is loosened and retreated, the balls 18 are made to be able to move inward in the radial direction, and the retainer 14 is pulled out in the direction of the arrow X. , as shown in FIG. 5, the ball 18 comes into contact with the inclined (tapered) surface 15a of the deformed rectangular groove 15 of the valve body 1, and the reaction force generated at this time R ₁
The ball 18 is accommodated in the small hole 16 by the component force _R
depart from.

In the above-described embodiment, a structure was described in which the annular groove 15 provided on the inner circumferential surface of the valve body was formed into a modified rectangular cross section with an inclined surface 15a. When pulling the ball 18 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 formed in the seat ring retainer 14 and having an inclined surface at the end. I explained about the small hole in the retainer.
Insert a rotating shaft having a notch with a crescent-shaped cross section perpendicular to the axis in the portion corresponding to 6 into the tap hole 17, and rotate the rotating shaft by 90 degrees so that it comes into contact with the notch. It is also possible to move the balls 18 in the adjoining eyelets 16 in a radial direction.

(Effects of the invention) As explained above, according to the invention, the seat ring retainer that holds the annular seat ring in a predetermined position is inserted into the annular groove provided on the inner peripheral surface of the valve body on the outer peripheral surface of the retainer. By engaging the radially movable ball installed in the valve body and fixing it to the inner surface of the valve body, the valve body and the seat ring retainer are compatible, and the ball's radially movable member can be housed within the seat ring retainer, so there is no need to impose any particular restrictions on the size of the seat ring.

Further, since the retainer can be freely attached to and detached from the valve body by engaging or disengaging the balls with the annular groove on the inner circumference of the valve body, the seat ring can be easily attached to and detached from the inner surface of the valve body.

[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 front view of the seat ring retainer in Fig. 1, Fig. 2a is an enlarged view of section A in Fig. 2, Figs. 3 to 5 are action explanatory views, and Figs. 6 and 7 are different FIG. 2 is a sectional view of a main part showing a conventional example. DESCRIPTION OF SYMBOLS 1... Valve body, 2... Valve body, 3... Seat ring, 14... Seat ring retainer, 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 having a seat ring and a seat ring retainer separately, an annular seat ring is disposed on the inner periphery of the annular valve body, and the seat ring is held in a predetermined position. For this purpose, a seat ring retainer is provided on one end wall surface of the valve body so as to be in contact with one side surface of the seat ring on the inner surface of the valve body, and an annular retainer provided on the inner peripheral surface of the valve body to which the seat ring retainer is attached is provided. A groove, a plurality of balls installed on the outer peripheral surface of the seat ring retainer and movable in the radial direction, and a member for moving these balls in the radial direction, and the engagement between the annular groove and the balls causes the valve body and the seat ring to A seat ring holding device for a butterfly valve, characterized in that the retainer is solidified and the seat ring is fixed to the inner surface of the valve body. 2 The member that moves the ball in the radial direction is
It is arranged to be inserted from one side wall of the seat ring retainer, and consists of a bolt with an inclined surface at the end, and by screwing or loosening the bolt, the balls are moved in the radial direction. A seat ring retaining device for a butterfly valve according to claim 1, which is adapted to be engaged with or disengaged from an annular groove on the inner peripheral surface of the valve body. 3. The butterfly according to claim 1, wherein the annular groove provided on the inner circumferential surface of the valve body where the seat ring retainer is attached is a modified rectangular groove whose cross section has an outwardly inclined surface. Valve seat ring retainer.