JPS6249510B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention comprises a valve housing having a valve seat, and a shaft passing through the valve housing with a throttle.
The present invention relates to a toothed valve incorporating a throttle arranged to rotate between an open position and a closed position in which a sealing surface of the throttle is pressed against a valve seat in the valve housing.

Current post-shaped valves are usually of the soft gas get type. A very common type of valve is e.g.
It is disclosed in the specification of Swedish Patent No. 199078. In this type of valve, the entire valve housing is lined with a soft material, such as rubber or other polymer. Examples of this type of valve are described in Swedish Patent Nos. 175149 and 178131. Alternatively, a soft sealing element may be arranged on the sealing surface of the throttle. Examples of this type are described in Swedish patent no. 195072 and German patent nos. 1011683 and 1232422.

A disadvantage of soft sealing elements in butterfly valves is that the resistance of these elements to hot media is often low. Although it is true that the insensitivity of synthetic rubbers and certain other polymers to high temperatures is slowly improving, these materials still have a resistance to high temperatures that is comparable to that of steel and other metals and alloys. There is no comparison. The same holds true for resistance to certain aggressive chemical media. In these cases as well, the properties of high grade stainless steels and other alloys are significantly superior to those of soft materials such as rubber. These circumstances are of course well known, and attempts have already been made to replace the soft sealing elements with metal ones. However, in these cases, the sealing is not sufficient or the associated sealing devices and/or equipment are extremely complex, so that this type of valve has not been of much practical use so far. An example of a valve belonging to this category is described in the specification of Swedish Patent No. 193,923.

The main object of the invention is to provide a wedge-shaped valve which has good sealing ability and does not contain soft sealing elements made of rubber, plastic or similar materials. In particular, it is an object to provide a valve that has a good sealing ability and can be manufactured entirely from metal. However, it is an object of the invention to allow the use of softer materials such as PTFE and nylon without departing from the principles of the invention. It is also an object to use materials of this kind, for example in valve seats, if for some reason they are more suitable or desirable than metallic materials. In other words, one aim of the invention is to allow a free choice between different materials depending on the medium in which the valve is intended to be used.

Another object is to provide a valve that does not primarily come into contact with the valve seat, which is advantageous from a wear point of view, when the throttle is rotated from a shut-off position to an open position and vice versa.

It is also an object of the present invention to provide a chimney valve that is robust, reliable, easy to operate and has a long life.

The above and other objects provide that the sealing surfaces of the rotary throttle are intersected by a plane of symmetry passing through the throttle and perpendicular to the axis of rotation of the throttle; two mutually opposed substantially spherical portions on either side of the plane of symmetry between two substantially conically shaped portions; This can be achieved by merging the generally spherical parts one after another into one another.

Furthermore, according to the invention, the pivot axis of said conically shaped surface is arranged at a slight angle to the axis coincident with said plane of symmetry and perpendicular to the pivot axis of the damper. The angle can vary depending on the angle between the pivot axis and the generatrix and is also determined by the dimensions of the throttle, such as its diameter and the width of the sealing surface. In normal cases, the angle should be between 5° and 8°. At the same time, the angle between the conical parts, ie the angle of the top slope of the cone, ranges from 10° to 40°, and the optimum angle is determined.

According to the invention, the valve seat made of flexible material deforms in a radial direction when the sealing surface of the throttle is pressed against it, determined by the point of contact between the valve seat and the sealing surface of the throttle. The position can match the shape of the surroundings of the sealing surface. According to the invention, the curve essentially consists of an elliptic curve whose major axis coincides with the plane of symmetry of the throttle. In the open position of this valve, the valve seat also has a rather circular shape. This means that
means that the valve seat is flexible at the level of the valve seat such that it is stretched by the conical surface in the direction of the major axis and simultaneously compressed in the direction of the minor axis to maintain a substantially constant circumference; ing. The valve seat is
The valve housing is suitably arranged for movement within an annular groove within the valve housing. According to the best way of carrying out the invention, said annular groove is formed by a pair of spring washers which are pressed against either side of the valve seat ring for sealing reasons.

The features of the invention, as well as further objects and advantages, will become apparent from the following description of the best mode of carrying out the invention.

Referring first to FIG. 1, there is shown a side view of a throttle according to the best mode of carrying out the invention, the throttle being designated generally by the numeral 1. The throttle 1 includes a throttle disk 2 having an annular sealing surface 4.
and bearing 3. The average line a extending over the entire sealing surface 4 has an elliptical shape. More specifically, the mean line a forms an ellipse obtained as a tapered cross-section through an imaginary cone with a top slope angle β, and the perpendicular b to the level of the tapered cross-section forms an angle α to the axis c of this cone. form.

The torsion axis j of the throttle 1, which is an axis parallel to the level of the mean line a, is offset by a distance X from said level. In particular, if the angle γ is substantially equal to the angle α between the center line of the conically shaped surface and the perpendicular to the plane formed by the substantially elliptically shaped curve a, then the substantially elliptically shaped surface The perpendiculars d and e from the intersections f and g between the curve a and its long axis to the torsion axis j are (90° + γ) and (90° - γ), respectively, with respect to the generatrix of the conical surface.
The torsion axis j is parallel to the plane determined by the curve a passing around the circumferential surface of the sealing surface so that
Specifically, the distance X is selected such that the angle γ=α.

These geometric conditions are such that _the radius of the arc drawn by the point f ₁ in FIG. means larger. On the opposite side of the sealing surface 4, ie in the conical area of point g, the above relationship is reversed. That is, the arc created by point g ₁ has a smaller radius than the arc created by point g ₂ . These relationships can also be expressed as follows.

jf ₁ > jf > jf ₂ and _{jg 2} > jg > jg In the area of points f and g, that is, in the area of the intersection between the mean line a and the long axis, the sealing surface 4 has a conical shape. ing. However, in the area of intersections h and i between the short axis and the mean line a, the sealing surface 4 is formed in a spherical shape, and the radius R of this spherical shape is formed by the mean line a from the points h and i. corresponds to the distance to the center of the ellipse. In the area between the conical part and the spherical part of the sealing surface 4, the conical shape and the spherical shape successively merge into one another. The shape of the throttle 1 may be manufactured by copying a casting workpiece.

In FIGS. 2-4, the valve housing is designated generally at 5. In FIGS. The valve housing 5 is provided with a circular opening 6 for the medium to be introduced through this valve, and this opening 6 is located somewhat below the long axis of the ellipse produced by the mean line a on the sealing surface 4 of the throttle 1. It has a large diameter.
The valve housing 5 has a flange 7 for connection of the regulating device and a filler foot 8 mounted by a stem. A pair of lugs 10 are provided with holes 11 to facilitate attachment to tubing.

A valve stem 12 carried in a bearing in the valve housing 5 passes through said housing and is clamped on the control side by a packing box 13 and on the opposite side by a plug 14. Furthermore, the valve stem 12 passes through the bearing 3 of the throttle 1. The throttle 1 is attached to the valve stem 12 by a conical stud 15. The axis of the spindle coincides with the torsional axis j of the throttle.

A cover plate 16 is attached to the valve housing 5 by screws 17. A valve seat 18 is arranged between the cover plate 16 and the valve housing 5. Valve seat 1
8 consists of a relatively flat ring with a rounded inner edge. The phrase "relatively flat" is used herein to mean that the thickness is less than the radial extent.
The material of the seat ring 18 is usually steel or some other alloy, but other relatively hard but somewhat plastic materials are contemplated, such as some rigid plastic-type PTFE. The valve seat ring 18 is carried in a bearing between a pair of mutually opposed spring washers 19 and 20, said spring washers forming a groove 21;
The valve seat is movable in the radial direction within this groove. The two gaskets each have a code 22.
and 23.

Said flat ring forming the valve seat 18 is in the rest position. That is, when the valve is open, it has a completely circular shape. the valve stem to the second
When the valve is closed by rotation about the torsional axis j in the counterclockwise direction in FIGS. It will slide towards. The distance between the torsion axis j and the contact point of the conical part increases successively as the throttle is rotated counterclockwise ( jf ₂ < jf <
jf ₁ and jg ₁ < jg < jg ₂ ), the conical portion of the sealing surface 4 is aligned with the valve seat ring 18 in the direction of the long axis of the mean line a.
will stretch out. At the same time, the valve seat ring 18 flexes inwardly in the direction of its minor axis so that the circumference of said valve seat remains largely constant. Finally, the valve seat is pressed against the sealing surface 4 over its entire circumference, which means that the valve seat 18 is at the mean line a.
This occurs when the ellipse shape matches the shape of the ellipse. This means that in this position the valve seat 18 also presses against the spherical part of the sealing surface. In this position the spherical portion of the sealing surface acts as a spherical sliding bearing towards the valve seat 18 to maintain the flatness of the valve seat with as little wear as possible. Furthermore, the deformation of the valve seat 18 at the level of the valve seat is negligible and well within the limits of the elasticity of the material. When the throttle is opened by clockwise rotation of the throttle in FIGS. 2 and 4 from the closed position, the valve seat will resume its original circular shape. At the same time,
The surface contact between the throttle 1 and the valve seat is opened by the valve seat flexing in the direction of the minor axis, restoring a greater full circular extent in said direction.
During most of the rotation of the throttle from the closed position to the open position and vice versa, the throttle is
8, which is of course very advantageous from the viewpoint of wear and tear.

[Brief explanation of the drawing]

1 shows the geometry of the throttle installed in the valve; FIG. 2 is a plan view of a spiral valve according to the best mode of carrying out the invention; and FIG. FIG. 4 is a sectional view taken along the line - in FIG. 2, and FIG. 4 is a sectional view taken along the line - in FIG. DESCRIPTION OF SYMBOLS 1... Throttle, 2... Throttle disc, 3... Bearing, 4... Annular seal surface, 5... Valve housing, 6... Circular opening, 7... Flange, 8... Filler holder, 10... Lug, 12... Valve stem, 13... Packing box, 14... Plug, 18... Valve seat, a... Elliptical curve, d, e... Perpendicular line, f, g... Conical part, h, i
...spherical part, j...torsion axis.

Claims (1)

[Scope of Claims] 1. A valve housing having a valve seat, and a valve shaft that rotates around a valve stem passing through the valve housing between a release position and a shutoff position in which the sealing surface on the throttle is pressed against the valve seat of the valve housing. and a throttle arranged such that said sealing surfaces 4 are formed by two mutually opposite planes of symmetry passing through the throttle and perpendicular to the torsional axis j of the throttle. substantially conically shaped portions f, g and two substantially spherically shaped portions h, i provided on each side of said axis of symmetry between said two substantially conically shaped portions; 1. A butterfly-shaped valve comprising: said substantially conical portion and said substantially spherical portion being successively merged into one another. 2. In the chimney-shaped valve according to claim 1, the torsion axis j parallel to the plane determined by the curve a passing around the periphery of the sealing surface is substantially elliptical curve a and its The perpendiculars d and e from the intersections f and g between the long axes to the torsion axis j are at an angle (90° +
γ) and (90° − γ), the angle γ being with respect to the plane formed by the center line of the conically shaped surface and said substantially ellipsoidal curve a. A butterfly-shaped valve characterized in that it is substantially equal to the angle α between it and the perpendicular. 3. The tooth-shaped valve according to claim 2, characterized in that the angle is between 5° and 8°. 4. The tooth-shaped valve according to claim 3, characterized in that the angle of the top slope of the conical surface is 10° to 40°. 5 Comparison of the valve according to any one of claims 1 to 4, in which the valve seat is arranged to be able to move radially into a groove in the valve housing 5. target flat ring 18
A chiffon-shaped valve characterized by being made by. 6. A tooth-shaped valve according to claim 5, wherein the valve seat ring 18 has a circular shape in its rest position.