阅读说明：本技术 一种四偏心蝶阀 (Four-eccentric butterfly valve ) 是由 林凯宇 邢懿 黄赛荣 徐艳华 刘辉 于 2019-11-26 设计创作，主要内容包括：一种四偏心蝶阀,包括阀体、密封圈、密封垫环、压板、蝶板、阀杆,密封垫环安装在蝶板的台阶上,密封圈压在密封垫环上,压板通过螺栓连接蝶板,阀杆通过销连接蝶板,阀体上密封面为正圆密封面,阀杆中心线与密封面中心线的偏心距e为第一偏心,阀杆中心线与蝶阀通道中心线的偏心距b为第二偏心,密封圈的密封面形成的锥体中心线与蝶阀通道中心线形成夹角α为第三偏心,密封面锥体内椭圆形密封面的短轴长度延短轴双向各延长偏心距f,使其短轴和长轴相等,偏心距f为第四偏心。本发明的有益效果是,通过增加一个偏心来完成椭圆密封面到正圆密封面的转变,解决了传统三偏心蝶阀椭圆密封面应力分布不均匀。(A four-eccentric butterfly valve comprises a valve body, a sealing ring, a sealing gasket ring, a pressing plate, a butterfly plate and a valve rod, wherein the sealing gasket ring is installed on a step of the butterfly plate, the sealing ring is pressed on the sealing gasket ring, the pressing plate is connected with the butterfly plate through a bolt, the valve rod is connected with the butterfly plate through a pin, the upper sealing surface of the valve body is a perfect circle sealing surface, the eccentric distance e between the central line of the valve rod and the central line of a sealing surface is a first eccentric, the eccentric distance b between the central line of the valve rod and the central line of a butterfly valve channel is a second eccentric, an included angle α is formed between the central line of a cone formed by the sealing surface of the sealing ring and the central line of the butterfly valve channel is a third eccentric, the length of a short shaft of an elliptic sealing surface in the cone of the sealing surface is respectively prolonged by an eccentric distance f along the two directions of the short shaft, so that the short shaft and the.)

1. A four-eccentric butterfly valve comprises a valve body, a sealing ring, a sealing gasket ring, a pressing plate, a butterfly plate and a valve rod, wherein the sealing gasket ring is installed on a step of the butterfly plate, the sealing ring is pressed on the sealing gasket ring, the pressing plate is connected with the butterfly plate through a bolt, the valve rod is connected with the butterfly plate through a pin, the four-eccentric butterfly valve is characterized in that a sealing surface on the valve body is a perfect circle sealing surface, the eccentricity e between the central line of the valve rod and the central line of the sealing surface is a first eccentricity, the eccentricity b between the central line of the valve rod and the central line of a butterfly valve channel is a second eccentricity, an included angle α formed between the central line of a cone formed by the sealing surface of the sealing ring and the central line of the butterfly valve channel is a third eccentricity, the length of a short shaft of an elliptic sealing surface in the cone body is.

Technical Field

The invention relates to a butterfly valve, in particular to a four-eccentric center butterfly valve.

Background

Butterfly valves have experienced the evolution of several structural forms, namely a center line butterfly valve, a single-eccentric butterfly valve, a double-eccentric butterfly valve and a triple-eccentric butterfly valve, in the history of their development.

At present, the three-eccentric butterfly valve is a butterfly valve form with wide application range and good use effect, the three-eccentric butterfly valve is characterized in that a second eccentric angle is added on the basis of a double-eccentric butterfly valve to reduce a second eccentric distance and further reduce the opening torque, but the sealing surface of the three-eccentric butterfly valve is not a circle but an ellipse, and the sealing mode of the three-eccentric butterfly valve is changed from position sealing to torsion sealing, so that the three-eccentric butterfly valve is suitable for being used for metal hard sealing, can resist high temperature and high pressure, has the function that the valve is closed more and more tightly, and has zero leakage in the sealing effect.

However, the three-eccentric butterfly valve has obvious disadvantages, and the elliptical sealing surface of the three-eccentric butterfly valve has the problems of uneven stress distribution and uneven wear of the sealing surface under the combined action of medium pressure and torque force of a driving device, for example, as shown in a sealing surface stress distribution diagram in fig. 1, when the sealing surface is subjected to the medium pressure, the stress at the short axis of the ellipse is concentrated, and the stress at the long axis of the ellipse is dispersed, so that the friction force between the sealing ring at the short axis and the sealing position on the valve body is the largest, and the friction force between the sealing ring at the long axis and the sealing position on the valve body is the smallest, so that the whole sealing ring is unevenly worn, and after multiple opening and closing actions, the short axis of the sealing surface of the butterfly valve leaks firstly, so that the.

Disclosure of Invention

In order to overcome the problems in the prior art, the invention provides the four-eccentric butterfly valve which enables the stress distribution of the sealing surface to be uniform, ensures that the micro abrasion of the whole sealing surface is uniform after the sealing ring is opened and closed for many times, fundamentally solves the sealing leakage problem caused by the fast abrasion of the short shaft and the slow abrasion of the long shaft of the original elliptical sealing surface, and improves the sealing performance of the butterfly valve and the service life of the sealing ring.

The technical scheme of the invention is that the four-eccentric butterfly valve comprises a valve body, a sealing ring, a sealing gasket ring, a pressure plate, a butterfly plate and a valve rod, wherein the sealing gasket ring is arranged on a step of the butterfly plate, the sealing ring is pressed on the sealing gasket ring, the pressure plate is connected with the butterfly plate through a bolt, the valve rod is connected with the butterfly plate through a pin, a sealing surface on the valve body is a perfect circle sealing surface, the eccentric distance e between the central line of the valve rod and the central line of the sealing surface is a first eccentric distance, the eccentric distance b between the central line of the valve rod and the central line of a channel of the butterfly valve is a second eccentric distance, an included angle α formed between the central line of a cone formed by the sealing surface of the sealing ring and the central line of the channel of the butterfly valve is a third eccentric distance, the length.

The invention has the advantages that the conversion from the elliptical sealing surface to the perfect circular sealing surface is completed by adding one eccentric center, thereby solving the problems of the traditional three-eccentric center butterfly valve that the stress distribution of the elliptical sealing surface is uneven, the abrasion of the minor axis of the elliptical sealing surface is fast, and the abrasion of the major axis is slow, which causes the sealing leakage, realizing the zero leakage for a long time, and prolonging the service life of the four-eccentric center butterfly valve sealing ring; meanwhile, the shape of the sealing surface of the four-eccentric butterfly valve is changed, so that the second eccentricity of the four-eccentric butterfly valve can be designed to be smaller on the premise that the four-eccentric butterfly valve does not interfere with the sealing surface, the torque of the four-eccentric butterfly valve is reduced, and the model selection cost of the driving device is reduced.

Drawings

FIG. 1 is a graph of the stress distribution of a sealing surface of a conventional triple offset butterfly valve;

FIG. 2 is a schematic view of a sealing surface right circular cone of a conventional triple offset butterfly valve;

FIG. 3 is a schematic view of a sealing surface right circular cone of a conventional triple offset butterfly valve in the direction of A;

FIG. 4 is a top view of a sealing surface of a prior art triple offset butterfly valve;

FIG. 5 is a schematic structural view of the present invention;

FIG. 6 is a schematic elliptical cone of the sealing face in the configuration of the present invention;

FIG. 7 is a schematic view of the elliptical cone shape of the sealing surface in the configuration of the present invention in the direction A;

FIG. 8 is a top plan view of a sealing surface in a configuration of the present invention;

FIG. 9 is a graph of the valve seal face stress distribution of the present invention;

FIG. 10 is a three-dimensional view of a right circular cone formed by a sealing surface of a conventional triple offset butterfly valve;

FIG. 11 is a three-dimensional view of an elliptical cone formed by a sealing surface in accordance with the present invention;

FIG. 12 is a projection of an elliptical cone formed by the seal ring of the present invention in the XOY plane;

FIG. 13 is a projection of an elliptical cone formed by the seal ring of the present invention in the OGH plane;

FIG. 14 is a cross-sectional view of the plane defined by G1H1 and A1B1 intersecting an elliptical cone;

FIG. 15 is a bottom elevational view of the cone of FIG. 11.

In the figure, 1, a valve body, 2, a sealing ring, 3, a sealing gasket ring, 4, a pressure plate, 5, a butterfly plate, 6, a valve rod, e, a first eccentricity, b, a second eccentricity, α, a third eccentricity and f, a fourth eccentricity are included.

Detailed Description

As shown in fig. 5-9, a four-eccentric butterfly valve includes a valve body, a seal ring, a pressure plate, a butterfly plate, and a valve rod, the seal ring is mounted on a step of the butterfly plate, the seal ring is pressed on the seal ring, the pressure plate is connected to the butterfly plate through a bolt, the valve rod is connected to the butterfly plate through a pin, a sealing surface on the valve body is a perfect circle sealing surface, an eccentric distance e between a center line of the valve rod and a center line of the sealing surface is a first eccentricity, an eccentric distance b between the center line of the valve rod and a center line of a channel of the butterfly valve is a second eccentricity, an included angle α formed between a center line of a cone formed by the sealing surface of the seal ring and the center line of the channel of the butterfly valve is a third eccentricity, a length of a short axis of.

Designing a calculation principle:

as shown in fig. 10, the bottom surface is a perfect circle, the diameter thereof is the length of AB, the radius thereof is r, the included angle between any generatrix and the central line of the cone is θ, the vertex O of the perfect cone is the origin of the spatial rectangular coordinate system, the plane perpendicular to the linear CD is the X axis, the plane parallel to the linear CD is the Y axis, the plane perpendicular to the XOY is the Z axis, the spatial rectangular coordinate system is established, the figures obtained by beveling the generatrix of the ellipse with any plane are standard elliptical surfaces, the plane of the linear CD and the plane of the linear EF are parallel to each other, and the upper and lower two surfaces cut by the two planes cutting the perfect cone are elliptical surfaces, the formed solid figure is the sealing ring of the three-eccentric butterfly valve, the bottom surface of the perfect cone is respectively extended and stretched along the three-eccentric minor axis in two directions (i.e. the Z axis direction) until the elliptical sealing surface is a perfect circle, at this time, the perfect cone has become an elliptical cone, the perfect circle of the bottom surface is already an ellipse, and the eccentricity f of the bottom surface in the Z-axis direction is a fourth eccentricity.

As shown in FIG. 11, the bottom surface is an ellipse, the straight line AB is a minor axis of the ellipse, the straight line GH is a major axis of the ellipse, the angle corresponding to the minor axis in the XOY plane is θ, and the angle corresponding to the major axis in the XOZ plane is θ, and the angle corresponding to the minor axis is θ, and the angle corresponding to the major axis is θ ₁The plane of the straight line CD is intersected with the elliptical cone to obtain a graph which is a perfect circle, the plane of the straight line EF is parallel to the plane of the straight line CD, the graph which is intersected with the elliptical cone is also a perfect circle, a real object which is cut out by the plane of the straight line CD and the plane of the straight line EF is just the sealing ring, and the upper end face and the lower end face of the sealing ring are both perfect circles. Taking XOY plane as a research coordinate system, the projection of the elliptic cone in the XOY plane is shown in FIG. 12, wherein the straight line AB is the short axis of the elliptic cone, the point S is the middle point of the straight line AB, the straight line OS is the central line of the elliptic cone (namely the straight line OS is vertical to the straight line AB), the straight line OS is intersected with the straight line CD at the point P, the middle point I of the straight line CD is taken, the OI is connected, the straight line OI is extended, the straight line AB is intersected with the point T, any plane parallel to the plane of the straight line CD is used for cutting the elliptic cone, the cut planes are all right circular planes, the central point of any right circular is on the straight line OT, the passing point I is taken as the vertical line of the straight line OS, the straight line OS is on the point Q, the vertical point is taken as the point Q ₁AC-DC line OA at point A ₁The crossing point D is a perpendicular line of the straight line OS, the crossing point K is the straight line OS, the included angle between the straight line OS and the central line of the channel in the valve body is α,

。

in this elliptical cone, only theta is derived ₁The elliptic cone can be determined as a function of theta, α, and the value of the fourth eccentricity f can be derived by further geometric transformation, where the values of theta and α are as given by the designerThe detailed calculation process belongs to the design input parameters and comprises the following steps:

taking fig. 12 as an example, the calculation is as follows:

in △ ODK ∠ DOK ═ theta,

|DK|＝h

in Δ OCD:

passing through point Q, making the parallel line of straight line CD, intersecting with the extension line of straight line KD at point D1, and | QD ₁|＝|ID|。

At △ KQD ₁The method comprises the following steps:

in △ KDP:

in △ IPQ:

at △ OQA ₁The method comprises the following steps:

in FIG. 11, the projection of the elliptical cone in the plane formed by the OGH is shown in FIG. 13, and the straight line G in FIG. 13 ₁H ₁In the plane of the line A in FIG. 11 ₁B ₁In a plane ofThe same plane, the intersection of which with the elliptical cone results in a figure which is elliptical parallel to the base of the elliptical cone, when viewed in a direction perpendicular to the plane of the ellipse, resulting in figure 14, wherein A ₁B ₁Is the minor axis of the ellipse, G ₁H ₁A new rectangular coordinate system X is established for the major axis of the ellipse with the point S in FIG. 14 as the origin ₁SY ₁。

At △ OQG of FIG. 13 ₁The method comprises the following steps:

in fig. 14:

the ellipse is in rectangular coordinate system X ₁SY ₁The ellipse equation in (1) is:

point I ₂The coordinate is (X) _I- | IQ |), i.e. (X) _I，-

）

Handle I ₂Coordinates, | G ₁O|、|A ₁The value of O | is substituted into the ellipse equation:

after the solution is solved into a quadratic equation, the difference of the two solutions is solved:

i.e. point I ₁And point I ₂The length of the space is:

in fig. 14, since a graph in which a plane on which a straight line CD is located intersects an elliptical cone is a perfect circle and a point I is a center of the perfect circle, a diameter = | CD | = | I of the perfect circle ₁I ₂|

Namely:

(relational expression 1)

As can be seen from the above, the relation 1 relates to θ ₁Theta and α, where theta and α are design input parameters, the butterfly valve designer defines the parameters by himself according to the internal standard of the company, theta ₁The numerical value can be calculated according to the relation.

Returning to the elliptical cone of fig. 11:

and r is the radius of the base circle of the right circular cone before stretching the elliptic cone

Namely:

namely:

in △ OAS of FIG. 12:

in △ OGS of FIG. 13:

FIG. 15 is a bottom elevational view of the cone of FIG. 11:

in fig. 15: the value of the fourth eccentricity f is:

(relational expression 2)

In summary, the relation 2 relates to θ ₁And theta and r, wherein the theta and the r belong to design self-defined input parameters, the value of the fourth eccentricity f is obtained through the relational expression 2, after all the parameters are determined, the key parameters of the design of the four-eccentricity butterfly valve are known, and the design of other parts is designed according to the relevant standard.

The technical scheme completes the conversion from the elliptical sealing surface to the perfect circular sealing surface by adding one eccentric center, solves the problems of sealing leakage caused by uneven stress distribution of the elliptical sealing surface, fast abrasion at the short axis and slow abrasion at the long axis of the elliptical sealing surface of the traditional three-eccentric center butterfly valve, can realize zero leakage for a long time, and prolongs the service life of the sealing ring of the four-eccentric center butterfly valve; meanwhile, the shape of the sealing surface of the four-eccentric butterfly valve is changed, so that the second eccentricity of the four-eccentric butterfly valve can be designed to be smaller on the premise that the four-eccentric butterfly valve does not interfere with the sealing surface, the torque of the four-eccentric butterfly valve is reduced, and the model selection cost of the driving device is reduced.

The present embodiment is only for explaining the present invention, and it is not limited to the present invention, and those skilled in the art can make modifications of the present embodiment without inventive contribution as needed after reading the present specification, but all of them are protected by patent law within the scope of the claims of the present invention.