JPS63101582A - Butterfly valve - Google Patents

Abstract

PURPOSE:To prevent securely the leakage attributable to the separation of a valve body from the valve seat, by arranging the inner circumferential inclined surface of a valve-seat ring so that it intersects with the tangent line of the locus circle, which is produced by the outer circumferential periphery of the valve body, within a range of specific angles in such a condition at it is not in contact with the valve body. CONSTITUTION:The angle theta of inclination of an inner circumferential inclined surface 4 is determined so that the inner circumferential inclined surface 4 of a valve seat ring 2 intersects with the locus circle 9 which is described by the outer circumferential periphery 10 of a valve body 3 while it is turned, and that the angle alpha between the tangent line 11 of the locus circle 9 at the intersection 5 and the inner circumferential inclined surface 4 is within the range from 2-6 deg.. Accordingly, when the valve body 3 is in the full-close position as shown by the imaginary line, the valve body 3 is in the full-close position while pushing a valve seat ring 2, thus the valve body is prevented from being parted from the valve seat by the fluid pressure from the valve body side.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a butterfly valve, which fits into a large-diameter pipe with relatively high fluid pressure.

(Prior Art) Conventionally, butterfly valves for large-diameter pipes with relatively high fluid pressure have been designed with various backing configurations to prevent leakage when fully opened (for example, the present invention). Refer to the invention of Japanese Patent Publication No. 4-/303, which was carried out by the special applicant].

(Problems to be solved by the invention) The conventional valve leaks when the fluid pressure is extremely large: n
When attempting to prevent 'eJ, extremely high finishing precision is required, which poses a problem in terms of cost for fA production.

The present invention was created to solve this problem.
The purpose is to obtain a high-performance butterfly valve with a simple configuration at zero cost.

(Means for resolving the problem) In Fig. 5, the center of the valve stems is located at a position slightly deviated from the center line of the valve body (XX), and the elastic valve seat ring (2) is inserted into the valve stem through hole (XX). 13, the valve box (provided in the IJ and the valve body (3)
A butterfly valve is shown in which the valve seat ring (2) is provided with an inner and peripheral slope (4) such that the valve seat ring (2) is pushed outward when the valve seat ring (2) is in the fully closed position. In this butterfly-shaped valve, one aspect of the present invention is that, as shown in the first figure, the valve seat ring rotates against the axis mark circle (9) drawn by the outer circumferential edge G (l) due to the rotation of the valve body (3). (2
) intersect with each other, and the tangent aaD of the axis mark circle (9) at the intersection point (5) and the inner inclined surface (4) intersect, and the orientation) is 2 to 6o. The inner sloped surface (
The inclination angle (θ) of 4) was determined. The angle [ω
The preferred value is 3~110.

(Function) In the present invention, as described above, when the inner circumferential inclined surface (4) of the valve seat ring (2) does not contact the valve body (3), the valve body (3)
)'s outer peripheral end R (axis trace circle (9) formed by 1G and λ~, I.

Due to the configuration in which the valve body (3) 1 intersects in the range of
The peripheral edge of the valve body (3) that fits into the valve seat ring (3) from the direction of the smaller inner circumferential diameter of the valve seat ring (2) first engages the valve seat ring (2) at two points.
The valve contacts the inner peripheral edge of the valve seat ring (2) and moves to the fully closed position f2 without deforming the elastic valve seat ring (2). The peripheral edge of the matching valve body (3) contacts the valve seat ring (2) slightly before the fully closed position and moves to the fully closed position, but when the valve body (3) is in the fully closed position, (When the valve seat ring (2) is in the position shown by the imaginary line in the FA diagram), the valve seat ring (2) is in the fully closed position with the valve body (3) pushing the valve seat ring (21) as shown by the imaginary line in the figure. Therefore, leakage from the valve seat, which occurs when the valve body separates from the valve seat in response to fluid pressure from the valve body side, is reliably prevented.

In this case, if the angle between the tangent αυ of the axis trace circle (9) and the inner circumferential inclined surface (4) in A(5) is smaller than −〇, then the above-mentioned “ In order to achieve the effect of "valve seat leakage," there is an unbalanced component, and if the gap is larger than 6 degrees, significant stress will be generated on the valve body (3) and the valve seat ring 121K. This is not desirable.

(lol Example) In the embodiment shown in the first figure, the valve seat ring (2) is made of an elastic metal (e.g. /l-g stainless steel, /3 chrome steel, etc.) as shown in the second figure. metal], and the front end of the thick base (6) has the required wall thickness (hJ vertical part (7
) through the inner peripheral inclined surface (41).
), but the front end of the thick base (6) is made of elastic resin (e.g. Teflon) as shown in the third figure. It is also possible to provide a tapered part (85) of a required thickness (t1) with the inner circumferential inclined surface (4) through the vertical part (7) of tzJ. As shown, solid synthetic rubber (e.g. nitrile rubber, US D
It is also possible to use fluororubber manufactured by U Pont under the trade name of Piton. At this time, the vertical part (7) of the metal or plastic valve seat ring (2) shown in Figure 2 or Figure 3 (7)
) wall thickness (t2) (tzJ h and taper part +8)
+81 wall thickness (tl) (ts is a dimension necessary to maintain the required elasticity and strength of the valve seat ring (2).

Note that the rate at which the valve stem center n deviates from the center line (XX) of the valve box is approximately 1/100 of the inner diameter mark of the valve box.

As shown in Figure 1, the front side edge σ of the outer peripheral edge αα of the valve body (3) and the inner inclined surface (4) of the valve seat ring (2) are shown in Figure 6. ) is fully open position fi1k (from AAJ to fully closed position &
(It is a configuration diagram showing a state in which it rotates to the DDJ,
In the same figure, (R) indicates the position where the valve body (3) starts contacting the valve seat ring (2), and (CC) indicates the position where the valve body (3) starts contacting the valve seat ring (2).
) indicates the contact intermediate position tl.

Figure 6 shows the position (AA) of the valve body (3) shown in Figure 6, α
4 is a valve stem, and 131 is a valve stem through hole. In the figure, the solid double circle indicates the inner end 4 of the valve seat ring (2).

In Fig. 6, the lengths of the double solid lines indicated by αηα & α9 indicate that the valve body (3) is at the contact start position (BB), the contact intermediate position & (C (J, fully closed position), and Valve seat ring (2)
).

(Effects of the Invention) As described above, according to the present invention, a highly productive linear valve can be used to prevent valve seat leakage, which is caused by the valve disc separating from the valve seat in response to fluid pressure from the valve disc side. A linear valve that completely prevents leakage has the great effect of being obtained economically.

Brief explanation of the weak side The drawings show an embodiment of the linear valve according to the present invention, and FIG. 1 is a partially cutaway sectional front view showing the relationship between the valve body and the valve seat shaft.

Figure 2 is a front cross-sectional view of the valve seat shaft in the same example, Figure 3 is a front cross-sectional view of the valve seat shaft in the second embodiment, and Figure 4 is a front cross-sectional view of the valve seat shaft in the third embodiment. Figure 5 is a cross-sectional front view of the entire linear valve, Figure 6 is a front view of the configuration showing the state in which the valve body rotates from the fully open position to the fully closed position, and Figure 7 is a front view of the configuration. Side view of the same configuration, +IJ is the valve body (2), the valve seat shaft (3), the valve body (4), the inner peripheral slope (5), the intersection point (6), the thick base (7) The concave part (8) is the tapered part (9), and the axial trace is the circular concave part. Seat shaft holder diagram 1

Claims (5)

[Claims] (1) The valve stem center (Y) is located at a position slightly offset from the valve body center line (@XX@), and the elastic valve seat ring (2) is provided in the valve body avoiding the valve stem through hole, In addition, in a butterfly valve in which the valve seat ring is provided with an inner periphery inclined surface in such a manner that the valve seat ring is pushed outward when the valve body is in the fully closed position, the outer periphery due to rotation of the valve body, For the locus circle drawn by the edge,
The inner circumferential inclined surfaces of the valve seat ring intersect, and the angle (α) formed by the tangent of the axis mark circle (9) at the intersection point and the inner circumferential inclined surface is 2.
The inclination angle (θ) of the inner circumferential slope is within the range of ~6°.
A butterfly-shaped valve characterized by determining (2) The butterfly valve according to claim 1, wherein the angle (α) is in a range of 3 to 4 degrees. (3) In the butterfly valve according to claim 1, the valve seat ring is made of an elastic metal (for example, a metal such as 18-8 stainless steel or 13 chrome steel), and A butterfly-shaped valve characterized in that a tapered part with the required wall thickness (t_1) with the inner circumferential inclined surface is provided at the front end of the thick base via a vertical part with the required wall thickness (t_2). (4) In the butterfly valve according to claim 1, the valve seat ring is made of elastic synthetic resin (for example, Teflon) and is attached to the front end of the thick base to a required wall thickness (t). '_2) Required wall thickness (t'_1) with the inner peripheral inclined surface through the vertical part
A butterfly valve characterized by having a tapered portion of (5) The butterfly valve according to claim 1, wherein the valve seat ring is made of elastic synthetic rubber (for example, nitrile rubber) and is solid.