Background technology
Three-eccentric-butterfly-valve is due to that with special three eccentricity combining structure, can realize that the moment between valve plate and valve seat departs from or closed when butterfly valve is opened and closed, and after unlatching, valve plate, there is no interference, so as to greatly reduce frictional force, improves the durability of valve with valve seat;This structure is also beneficial to improve sealing property;Under the conditions of identical applied moment, the more other butterfly valves of three-eccentric-butterfly-valve have better seal performance, in addition, three-eccentric-butterfly-valve can also bear the pressure difference bigger than other butterfly valves, therefore, three-eccentric-butterfly-valve is widely used in various industrial productions.
Compared to other types of butterfly valve, the structure of three-eccentric-butterfly-valve is increasingly complex, and this just proposes higher requirement to product design.The problem of wherein size of seal contact face is interfered protrudes the most;Once generation dimensional interference, frequently can lead to leakage or stucking phenomena, while can also cause extra fretting wear, so as to largely effect on the using effect and service life of three-eccentric-butterfly-valve;In the design process of three-eccentric-butterfly-valve, its sealing surface design parameter(Particularly three obliquely intersecteds)Selection it is extremely important, and be how to judge whether design parameter can cause the appearance of dimensional interference phenomenon the problem of to the most critical of sealing surface Parameters Optimal Design;Due to the complexity of three-eccentric-butterfly-valve sealing surface parameter inner link, judge whether dimensional interference occur frequently with empirical parameter combination 3 d modeling software in engineering design, usually require to correct repeatedly to debug using this design cycle and could obtain preferable design parameter, therefore inevitably lead to the reduction of design accuracy and the extension of design cycle.
The content of the invention
A kind of simple decision method of three-eccentric-butterfly-valve size of seal contact face interference, is that can determine that whether butterfly valve seal face can interfere by this method, while can also judge the particular location of interference region, it is characterised in that carry out according to the following steps(Such as Fig. 1):
1)Determine design parameter
Obtain and determine 5 main design parameters of three-eccentric-butterfly-valve sealing surface(Fig. 2):The length of valve plate neutral surface transverse
D max , valve plate thickness be
t, it is axially eccentric
c, radial disbalance
e, and angle bias
。
2)Set up coordinate system
Summit to seal circular conical surface is x-axis perpendicular to valve plate in-plane, rectangular coordinate system is set up for y-axis parallel to the oval long axis direction of valve plate neutral surface as origin(Fig. 3);Valve plate thickness is
t, two intercept sideways in x-axis is respectively
x 1 With
x 2 , the oval long axis length of its neutral surface
D max ;Coordinate of the center of rotating shaft 3 in x/y plane is P(
x 0 ,
y 0 ), the cone angle of sealing circular conical surface is 2
;
,
。
3)Numerical discretization processing
To avoid solution and the complexity of judgement of the non-linear generation of Mathematical Modeling in itself, numerical value judgement is carried out using discrete method;Specifically, using z as primary variables, by its domain of definition:
Some deciles are divided into, and successively to variable z values;According to the symmetry of butterfly valve axially symmetric structure and coordinate system, can only it be investigated during practical operation
Interval, the result of rest interval can be obtained according to symmetry;For reduction trueness error caused by discrete processes as far as possible, interval is quantized after being at least divided into more than 100 grades point to variable z;For example variable z value can be taken as 0,
,
,
...,
。
4)Determine subregion
Assuming that have one parallel to x/y plane plane z=z
0, z
0For the centrifugal pump taken in step 3 to variable z.Two sections or one section of hyperbola are then intercepted on valve plate circular conical surface according to the plane, then in x/y plane, y domain of definition can be divided into two or a region;Specifically, when
When, plane z=z
0Two sections of hyperbolas, i.e. y domain of definition are intercepted on valve plate circular conical surface and is divided into two intervals;When
When, plane z=z
0It is only an interval that one section of hyperbola, i.e. y domain of definition are intercepted on valve plate circular conical surface;
。
5)Judge
In z=z
0In plane, it is assumed that M
1(
,
, z
0)For any point on hyperbolic line segment(Fig. 4);After valve plate is opened, M
1Turned clockwise around P points
Angle, is reached
Point, corresponding point is M in the angle, valve seat
2(
,
, z
0).Valve plate and valve seat during valve opening is then set not interfere, then its necessary and sufficient condition is:
, i.e.,
;In view of M
1Point and
The arbitrariness of angle,
It is equivalent to again:Any point M (x, y, z on hyperbolic line segment
0) and P (x
0,y
0,z
0) point the distance between function f (y) exist(x
1, x
2)It is interval(x
1<x
2)It is interior on y monotone increasings;Due to always there is f (y)>0, therefore the condition is also equivalent to
For monotonic increasing function, i.e.,
During judgement, constitutive equations(1)In function g (y);Bring each z value of the interval interior discrete acquisition of z domain of definition into inequality(2)Middle once to be judged, inequality is set up and is then recorded as 1, is otherwise 0;According to record result, if all 1, dimensional interference will not occur completely, if being not all 1, corresponding to 0 z values be on sealing surface by generation dimensional interference region z coordinate value.
Embodiment
Embodiment 1:
1)Determine design parameter
Obtain and determine 5 main design parameters of three-eccentric-butterfly-valve sealing surface:The length of valve plate neutral surface transverse
D max =250 mm, valve plate thickness are
tIt is=14 mm, axially eccentric
c=10 mm, radial disbalance
e=20 mm, and angle are eccentric
=13 °.
2)Set up coordinate system
Summit to seal circular conical surface is x-axis perpendicular to valve plate in-plane, rectangular coordinate system is set up for y-axis parallel to the oval long axis direction of valve plate neutral surface as origin;Valve plate thickness is
t, two intercept sideways in x-axis is respectively
x 1 With
x 2 , the oval long axis length of its neutral surface
D max ;Coordinate of the valve plate rotation axis in x/y plane is P(
x 0 ,
y 0 ), the cone angle of sealing circular conical surface is 2
。
3)Numerical discretization processing
Using z as primary variables, by its domain of definition:Progress is equidistantly discrete, and variable z value is followed successively by 0,1.216,2.432,3.648 ..., and 121.6mm。
4)Determine subregion
When
When, plane z=z
0Two sections of hyperbolas, i.e. y domain of definition are intercepted on valve plate circular conical surface and is divided into two intervals;When
When, plane z=z
0It is only an interval that one section of hyperbola, i.e. y domain of definition are intercepted on valve plate circular conical surface.
5)Judge
Construction
;Bring each z value of the interval interior discrete acquisition of z domain of definition into inequality
Middle once to be judged, inequality is set up and is then recorded as 1, is otherwise 0;According to record result;Obtain result:When
When, as a result all it is 1;When
When, as a result all it is 0;As a result illustrate:Can occur dimensional interference, and interference region is that z coordinate is met on sealing surface
Region.
Embodiment 2:
1)Determine design parameter
Obtain and determine 5 main design parameters of three-eccentric-butterfly-valve sealing surface:The length of valve plate neutral surface transverse
D max =250 mm, valve plate thickness are
tIt is=14 mm, axially eccentric
c=10 mm, radial disbalance
e=40 mm, and angle are eccentric
=13 °.
2)Set up coordinate system
Summit to seal circular conical surface is x-axis perpendicular to valve plate in-plane, rectangular coordinate system is set up for y-axis parallel to the oval long axis direction of valve plate neutral surface as origin;Valve plate thickness is
t, two intercept sideways in x-axis is respectively
x 1 With
x 2 , the oval long axis length of its neutral surface
D max , coordinate of the valve plate rotation axis in x/y plane is P(
x 0 ,
y 0 ).The cone angle for sealing circular conical surface is 2
。
3)Numerical discretization processing
Using z as primary variables, by its domain of definition:Progress is equidistantly discrete, and variable z value is followed successively by 0,1.216,2.432,3.648 ..., and 121.6mm。
4)Determine subregion
When
When, plane z=z
0Two sections of hyperbolas, i.e. y domain of definition are intercepted on valve plate circular conical surface and is divided into two intervals;When
When, plane z=z
0It is only an interval that one section of hyperbola, i.e. y domain of definition are intercepted on valve plate circular conical surface.
5)Judge
Construction
;Bring each z value of the interval interior discrete acquisition of z domain of definition into inequality
Middle once to be judged, inequality is set up and is then recorded as 1, is otherwise 0;According to record result;Obtain result:When
Or
When, as a result all it is 1;When
, as a result all it is 0;As a result illustrate:Can occur dimensional interference, and interference region is that z coordinate is met on sealing surface
Region.
Embodiment 3:
1)Determine design parameter
Obtain and determine 5 main design parameters of three-eccentric-butterfly-valve sealing surface:The length of valve plate neutral surface transverse
D max =240 mm, valve plate thickness are
tIt is=14 mm, axially eccentric
c=30 mm, radial disbalance
e=10 mm, and angle are eccentric
=14 °.
2)Set up coordinate system
Summit to seal circular conical surface is x-axis perpendicular to valve plate in-plane, rectangular coordinate system is set up for y-axis parallel to the oval long axis direction of valve plate neutral surface as origin;Valve plate thickness is
t, two intercept sideways in x-axis is respectively
x 1 With
x 2 , the oval long axis length of its neutral surface
D max ;Coordinate of the valve plate rotation axis in x/y plane is P(
x 0 ,
y 0 ), the cone angle of sealing circular conical surface is 2
。
3)Numerical discretization processing
Using z as primary variables, by its domain of definition:
Progress is equidistantly discrete, and variable z value is followed successively by 0,1.162,2.324,3.486 ..., and 116.2
mm。
4)Determine subregion
When
When, plane z=z
0Two sections of hyperbolas, i.e. y domain of definition are intercepted on valve plate circular conical surface and is divided into two intervals;When
When, plane z=z
0It is only an interval that one section of hyperbola, i.e. y domain of definition are intercepted on valve plate circular conical surface.
5)Judge
Construction
;Bring each z value of the interval interior discrete acquisition of z domain of definition into inequality
Middle once to be judged, inequality is set up and is then recorded as 1, is otherwise 0, according to record result, obtains result:When
When, all it is as a result 1, that is, illustrates on this sealing surface all without generation dimensional interference.