阅读说明：本技术 一种等截面椭圆流道旋塞阀 (Plug valve with uniform-section oval flow channel ) 是由 邵建农 于国峰 冯玉柱 米红娟 李士强 田志安 冯冰 于 2020-03-26 设计创作，主要内容包括：本发明公开了一种等截面椭圆流道旋塞阀,所述旋塞阀本体包括阀体,通过螺栓组件设置于所述阀体上的阀盖,设置于所述阀体内的阀腔,可转动设置于所述阀腔内的旋塞,所述旋塞的顶部延伸出所述阀盖后设置手轮,所述阀体包括左流道和右流道,所述旋塞上设置有旋塞孔,所述左流道、旋塞孔和所述右流道依次连通形成流体通道,所述流体通道左右对称设置,所述流体通道中心的中心流道截面为椭圆形,所述流体通道两端的端部流道截面为圆形,流体通道的流道截面从端部流道截面的圆形逐渐变为中心流道截面的椭圆形。采用本发明可大幅降低应力集中效应,提高流道的强度和刚度,减少材料消耗；并可大幅降低流体阻力,减少工作能耗。(The invention discloses a plug valve with an oval flow channel with a uniform cross section, wherein a plug valve body comprises a valve body, a valve cover arranged on the valve body through a bolt assembly, a valve cavity arranged in the valve body, a cock rotatably arranged in the valve cavity, and a hand wheel arranged behind the valve cover and extending out of the top of the cock. By adopting the invention, the stress concentration effect can be greatly reduced, the strength and the rigidity of the flow channel are improved, and the material consumption is reduced; and the fluid resistance can be greatly reduced, and the working energy consumption is reduced.)

1. The plug valve with the uniform cross section and the elliptical flow channel is characterized by comprising a valve body (1), a valve cover (3) arranged on the valve body (1) through a bolt component (2), a valve cavity (4) arranged in the valve body (1), and a plug (5) rotatably arranged in the valve cavity (4), wherein the top of the plug (5) extends out of the back of the valve cover (3) to form a hand wheel (6), the valve body (1) comprises a left flow channel (7) and a right flow channel (8), a rotary plug hole (9) is arranged on the plug (5), the left flow channel (7), the rotary plug hole (9) and the right flow channel (8) are sequentially communicated to form a fluid channel (10), the fluid channel (10) is bilaterally symmetrically arranged, a central flow channel cross section (28) at the center of the fluid channel (10) is elliptical, and end flow channel cross sections (27) at two ends of the fluid channel (10) are circular, the flow passage cross-section of the fluid passage (10) changes gradually from a circular shape in the end flow passage cross-section (27) to an elliptical shape in the center flow passage cross-section (28).

2. The plug valve with the uniform cross section and the elliptical flow channel as claimed in claim 1 is characterized in that the left end, the right end and the upper end of the valve body (1) are provided with connecting flanges (11).

3. The plug valve with the uniform cross section and the elliptical flow channel as claimed in claim 1, wherein the valve chamber (4) is a conical hole with a large upper part and a small lower part, the plug (5) is provided with an external conical surface, and the external conical surface of the plug (5) and the valve chamber (4) are matched to form a main sealing pair.

4. The plug valve with the uniform cross section and the elliptical flow channel is characterized in that an annular groove is formed in the upper part of the contact surface of the plug valve (5) and the valve body (1), a sealing assembly (12) is arranged in the annular groove, and auxiliary sealing pairs are formed among the sealing assembly (12), the valve body (1), the plug valve (5) and the valve cover (3).

5. The plug valve with the uniform cross section and the elliptical flow channel is characterized in that a square hole is formed in the center of the bottom of the hand wheel (6), and a square tenon (13) matched with the square hole is formed in the top of the plug valve (5).

6. An elliptical flow passage plug valve of uniform cross-section as claimed in claim 1 wherein the cross-sectional area of any flow passage on said flow passage (10) is equal.

7. A plug valve with an oval flow passage of uniform cross section according to claim 1 or 6,

the cross section of any flow passage from the end part to the center on the fluid passage (10) is elliptical,

the radius of the major axis of an ellipse on the section a of any flow channel on the fluid channel (10) is Y_aThe radius of the minor axis of the ellipse on the section a of any flow channel on the fluid channel (10) is Y_b＝R²/(R+Xa·tanθ)；

Xa is the distance between any flow channel section a and the end flow channel section (27) on the corresponding side;

setting the upper vertex of the central flow passage section (28) as a point N, the upper vertex of the end flow passage section (27) as a point G, and the straight line connecting the point G to the point N is a straight line GN, wherein theta is the included angle between the straight line GN and the central axis of the fluid flow passage;

r is the radius of the circle on the cross section (27) of the end flow passage.

8. An elliptical flow passage plug valve of constant cross-section as claimed in claim 7 wherein the circular area of the end flow passage cross-section (27) is assumed to be S₁＝πR²The elliptical area of any cross section on the fluid flow passage is S₂Then, then

S₂＝π·Y_a·Y_b＝π·(R+X·tanθ)·R²/(R+X·tanθ)＝πR²＝S₁。

9. The constant-cross-section elliptical-flow-channel plug valve of claim 1 wherein the flow-channel curve of the fluid flow channel comprises a line connecting the vertices of the major axis of the ellipse in the flow-channel cross-section and a line connecting the vertices of the minor axis of the ellipse in the flow-channel cross-section; the long axis vertex connecting line comprises a straight line A (14), a straight line B (15), a straight line C (16) and a straight line D (17), wherein the straight line A (14), the straight line B (15), the straight line C (16) and the straight line D (17) are symmetrically arranged by a central line A (18), and the straight line A (14), the straight line C (16), the straight line B (15) and the straight line D (17) are symmetrically arranged by a central line B (19); the straight line A (14) and the straight line B (15), and the straight line C (16) and the straight line D (17) are respectively connected through corresponding arcs (26);

the short-axis vertex connecting line comprises a curve A (20), a curve B (21), a curve C (22) and a curve D (23), wherein the curve A (20) and the curve B (21), the curve C (22) and the curve D (23) are symmetrically arranged with a central line C (24), and the curve A (20) and the curve C (22), the curve B (21) and the curve D (23) are symmetrically arranged with a central line D (25).

10. The constant-section elliptical flow channel plug valve according to claim 9, wherein the method for drawing the flow channel curve of the fluid flow channel specifically comprises the following steps:

step 1, taking a line segment X5 on an X axis, wherein the length of the line segment X5 is equal to 1/2 of the total length of the fluid flow channel, and dividing the line segment X5 into 5 equal parts which are respectively marked as a dividing point A, a dividing point B, a dividing point C, a dividing point D and a dividing point E; drawing parallel lines of the Y axis respectively across the bisectors and labeled as line P1, line P2, line P3, line P4, line P5;

step 2, taking a point Yar on the Y axis, and marking the point Yar as a point G; taking Y at P5_a5The point of the distance from the highest point of the flow channel to the X axis is marked as point N,

step 3, connecting a point G and a point N by using a straight line, namely a straight line GN, wherein the straight line GN intersects with a line P1, a line P2, a line P3 and a line P4 at a point H, a point J, a point K and a point M respectively; the heights of the point H, the point J, the point K and the point M are respectively marked as follows: y is_a1、Y_a2、Y_a3、Y_a4(ii) a The included angle between the straight line GN and the X axis is marked as theta; at this time, the major axis radius Y can be accurately measured_a1、Y_a2、Y_a3、Y_a4Or according to formula Y_aThe major semi-axis Y of the ellipse is calculated as R + X tan theta_a1、Y_a2、Y_a3、Y_a4、Y_a5A value of (d);

the straight line GN is a long axis vertex connecting line from the end part of the flow channel to the center of the flow channel, namely a straight line A (14); mirroring the straight line A (14) along a central line A (18) to obtain a straight line B (15), mirroring the straight line A (14) and the straight line B (15) along a central line B (19) to obtain a straight line C (16) and a straight line D (17); finally, the straight line A (14) and the straight line B (15) as well as the straight line C (16) and the straight line D (17) are respectively connected by using corresponding arcs (26), and a complete and smooth connecting line of the long axis vertex of the ellipse on the cross section of the runner can be obtained;

step 4, taking Y on the Y axis_b-R and is marked as point P,

step 5, using formula Y_b＝R²V (R + X tan. theta.) each Y was calculated_b1、Y_b2、Y_b3、Y_b4、Y_b5And according to Y_b1、Y_b2、Y_b3、Y_b4、Y_b5Respectively, take points on line P1, line P2, line P3, line P4, line P5, and mark as point S, point T, point V, point W, point Z; connecting the point P, the point S, the point T, the point V, the point W and the point Z by using a smooth curve to obtain a smooth curve PZ; a long axis vertex connecting line from the end part of the flow channel to the center of the flow channel, namely a curve A (20), can be obtained;

step 6, mirroring the curve A (20) along the center line C (24) to obtain a curve B (21); the curve A (20) and the curve B (21) are mirrored along the center line D (25), so that a curve C (22) and a curve D (23) can be obtained;

step 7, connecting a curve A (20) with a curve B (21), and connecting a curve C (22) with a curve D (23) with connecting lines of short axis vertexes of the flow channel section ellipse respectively;

step 8, drawing a circle with the point O as the center of a circle and the radius R as the radius in an XOY coordinate graph to obtain a circle T0, wherein the circle T0 is intersected with the X axis at a point P and is intersected with the Y axis at a point G;

step 9, taking the length of Y on the Y axis_a1、Y_a2、Y_a3、Y_a4、Y_a5The points of (a) are respectively a point H, a point J, a point K, a point M and a point N;

step 10, taking the length of Y on the X axis_b1、Y_b2、Y_b3、Y_b4、Y_b5The points of (1) are respectively a point S, a point T, a point V, a point W and a point Z;

step 11, taking the O point as the center of a circle, Y_a1、Y_a2、Y_a3、Y_a4、Y_a5Is a long semi-axis, Y_b1、Y_b2、Y_b3、Y_b4、Y_b5An ellipse T1, an ellipse T2, an ellipse T3, an ellipse T4 and an ellipse T5 can be obtained as a semi-minor axis;

and step 12, sequentially connecting the T0 with the T1, the T2, the T3, the T4 and the T5 by smooth curved surfaces to obtain a left half-section flow channel model curved surface, and mirroring the left half-section flow channel model curved surface along a central flow channel section (28) to obtain a right half-section flow channel model curved surface.

Technical Field

The invention relates to a plug valve, in particular to a plug valve with an oval flow passage and a uniform cross section.

Background

The cross sections of flow passages on two end surfaces of the existing plug valve are circular; in order to reduce the diameter of the cock, shorten the total length of the valve and reduce the material cost, the section of a central flow passage of the cock is generally a trapezoid or a rectangle with a wide upper part and a narrow lower part; the aspect ratio is generally above 2: 1; the flow passage from the two end surfaces to the center of the cock is a trapezoidal or rectangular transition surface with a non-uniform cross section. Since stress concentration in compression is caused at four corners of the trapezoid or the rectangle, the strength and rigidity of the flow channel are greatly reduced. In order to maintain sufficient strength and rigidity of the flow passage, the thickness of the valve body material must be greatly increased. In addition, the flow channels with non-uniform cross sections can also increase the fluid resistance and increase the energy consumption.

Disclosure of Invention

The invention provides a plug valve with an oval flow passage with a uniform cross section to solve the technical problems.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

the utility model provides an oval runner plug valve of uniform cross-section, includes the valve body, set up through the bolt assembly in valve gap on the valve body set up in valve pocket in the valve body, the rotatable setting in cock in the valve pocket, the top of cock extends set up the hand wheel behind the valve gap, the valve body includes left runner and right runner, be provided with on the cock and revolve the consent, left runner, revolve the consent with right runner communicates in proper order and forms fluid passage, fluid passage bilateral symmetry sets up, the central runner cross-section at fluid passage center is oval, the tip runner cross-section at fluid passage both ends is circular, and fluid passage's runner cross-section becomes the oval of central runner cross-section from tip runner cross-section circular gradually.

Furthermore, both ends and upper end all are provided with flange about the valve body.

Furthermore, the valve cavity is a conical hole with a large upper part and a small lower part, the cock is provided with an outer conical surface, and the outer conical surface of the cock is matched with the valve cavity to form a main sealing pair.

Furthermore, an annular groove is formed in the upper portion of the contact surface of the cock and the valve body, a sealing assembly is arranged in the annular groove, and auxiliary sealing pairs are formed among the sealing assembly, the valve body, the cock and the valve cover.

Furthermore, the sealing assembly is in a ring shape and is made of one or more materials of rubber, plastic, graphite and metal.

Furthermore, a square hole is formed in the center of the bottom of the hand wheel, and a square tenon matched with the square hole is arranged at the top of the cock.

Furthermore, the areas of the cross sections of any flow passages on the fluid channel are equal.

Further, the cross section of any flow passage from the end part to the center of the fluid passage is oval,

the radius of the major axis of an ellipse on the section a of any flow channel on the fluid channel is Y_aThe radius of the minor axis of the ellipse on the section a of any flow channel on the fluid channel is Y_b＝R²/(R+Xa·tanθ)；

Xa is the distance between the section a of any flow channel and the section of the end flow channel on the corresponding side;

setting the upper vertex of the central flow passage section as a point N, the upper vertex of the end flow passage section as a point G, and the straight line connecting the point G to the point N as a straight line GN, wherein theta is the included angle between the straight line GN and the central axis of the fluid flow passage;

and R is the radius of a circle on the section of the end runner.

Further, let the circular area of the cross section of the end flow passage be S₁＝πR²The elliptical area of any cross section on the fluid flow passage is S₂Then S is₂＝π·Y_a·Y_b＝π·(R+X·tanθ)·R²/(R+X·tanθ)＝πR²＝S₁。

Furthermore, the flow channel curve of the fluid flow channel comprises a connecting line of vertexes of a long axis of an ellipse on the cross section of the flow channel and a connecting line of vertexes of a short axis of the ellipse on the cross section of the flow channel; the long axis vertex connecting line comprises a straight line A, a straight line B, a straight line C and a straight line D, wherein the straight line A, the straight line B, the straight line C and the straight line D are symmetrically arranged by a central line A, and the straight line A, the straight line C, the straight line B and the straight line D are symmetrically arranged by a central line B; the straight line A and the straight line B, and the straight line C and the straight line D are respectively connected through corresponding arcs;

the short axis vertex connecting line comprises a curve A, a curve B, a curve C and a curve D, wherein the curve A and the curve B are symmetrically arranged with a center line C, and the curve A and the curve C are symmetrically arranged with the center line D.

Furthermore, the method for drawing the flow path curve of the fluid flow path specifically comprises the following steps:

step 1, taking a line segment X5 on an X axis, wherein the length of the line segment X5 is equal to 1/2 of the total length of the fluid flow channel, and dividing the line segment X5 into 5 equal parts which are respectively marked as a dividing point A, a dividing point B, a dividing point C, a dividing point D and a dividing point E; drawing parallel lines of the Y axis respectively across the bisectors and labeled as line P1, line P2, line P3, line P4, line P5;

step 2, taking a point Yar on the Y axis, and marking the point Yar as a point G; taking Y at P5_a5The point of the distance from the highest point of the flow channel to the X axis is marked as point N,

step 3, connecting the point G and the point by using a straight lineN, i.e. a straight line GN, which intersects the line P1, the line P2, the line P3, the line P4 at the point H, the point J, the point K, the point M, respectively; the heights of the point H, the point J, the point K and the point M are respectively marked as follows: y is_a1、 Y_a2、Y_a3、Y_a4(ii) a The included angle between the straight line GN and the X axis is marked as theta; at this time, the major axis radius Y can be accurately measured_a1、Y_a2、 Y_a3、Y_a4Or according to formula Y_aThe major semi-axis Y of the ellipse is calculated as R + X tan theta_a1、Y_a2、Y_a3、Y_a4、Y_a5A value of (d);

the straight line GN is a long axis vertex connecting line from the end part of the flow channel to the center of the flow channel, namely a straight line A; the straight line A is mirrored along the central line A to obtain a straight line B, and the straight line A and the straight line B are both mirrored along the central line B to obtain a straight line C and a straight line D; finally, the straight line A and the straight line B, and the straight line C and the straight line D are respectively connected by using corresponding arcs, and then a complete and smooth connecting line of the vertex of the long axis of the ellipse on the cross section of the runner can be obtained;

step 4, taking Y on the Y axis_b-R and is marked as point P,

step 5, using formula Y_b＝R²V (R + X tan. theta.) each Y was calculated_b1、Y_b2、Y_b3、Y_b4、Y_b5And according to Y_b1、Y_b2、Y_b3、Y_b4、Y_b5Respectively, take points on line P1, line P2, line P3, line P4, line P5, and mark as point S, point T, point V, point W, point Z; connecting the point P, the point S, the point T, the point V, the point W and the point Z by using a smooth curve to obtain a smooth curve PZ; obtaining a long axis vertex connecting line from the end part of the flow channel to the center of the flow channel, namely a curve A;

step 6, mirroring the curve A along the center line C to obtain a curve B; the curve A and the curve B are mirrored along the central line D to obtain a curve C and a curve D;

step 7, connecting the curve A with the curve B, and connecting the curve C with the curve D respectively with connecting lines of short axis vertexes of the flow channel section ellipse;

step 8, drawing a circle with the point O as the center of a circle and the radius R as the radius in an XOY coordinate graph to obtain a circle T0, wherein the circle T0 is intersected with the X axis at a point P and is intersected with the Y axis at a point G;

step 9, taking the length of Y on the Y axis_a1、Y_a2、Y_a3、Y_a4、Y_a5The points of (a) are respectively a point H, a point J, a point K, a point M and a point N;

step 10, taking the length of Y on the X axis_b1、Y_b2、Y_b3、Y_b4、Y_b5The points of (1) are respectively a point S, a point T, a point V, a point W and a point Z;

step 11, taking the O point as the center of a circle, Y_a1、Y_a2、Y_a3、Y_a4、Y_a5Is a long semi-axis, Y_b1、Y_b2、Y_b3、Y_b4、Y_b5An ellipse T1, an ellipse T2, an ellipse T3, an ellipse T4 and an ellipse T5 can be obtained as a semi-minor axis;

and step 12, sequentially connecting the T0 with the T1, the T2, the T3, the T4 and the T5 by smooth curved surfaces to obtain a left half-section flow channel model curved surface, and mirroring the left half-section flow channel model curved surface along the section of the central flow channel to obtain a right half-section flow channel model curved surface.

Further, the method also comprises a step 13 of modeling by adopting three-dimensional software; and then, processing by using a numerical control machine tool to obtain the three-dimensional solid model.

Compared with the prior art, the invention has the following beneficial effects:

the invention provides a plug valve with an oval flow channel with an equal section, which is characterized in that the central section of a fluid flow channel is designed to be oval, the end section of the fluid flow channel is designed to be round, and the flow channel section of a fluid channel is ensured to be gradually changed from the round shape of the end section of the flow channel to the oval shape of the central section of the flow channel, so that the stress concentration effect can be greatly reduced, the strength and the rigidity of the flow channel are improved, and the material consumption is reduced; the uniform cross-section structure from the circular flow channel on the end face of the fluid flow channel to the elliptical flow channel in the center of the fluid flow channel can greatly reduce the fluid resistance and reduce the working energy consumption.

Drawings

FIG. 1 is a schematic structural diagram of one embodiment of the present invention;

FIG. 2 is a cross-sectional view of FIG. 1;

FIG. 3 is a cross-sectional view of FIG. 2;

FIG. 4 is a schematic view of the valve body according to an embodiment of the present invention;

FIG. 5 is a schematic view of a faucet according to one embodiment of the present invention;

FIG. 6 is a method of plotting fluid flow channel ellipse vertex lines in accordance with one embodiment of the present invention;

FIG. 7 is a method of plotting fluid flow path curves in accordance with an embodiment of the present invention;

in the figure, 1, a valve body, 2, a bolt component, 3, a valve cover, 4, a valve cavity, 5, a cock, 6, a hand wheel, 7, a left flow passage, 8, a right flow passage, 9, a cock hole, 10, a fluid passage, 11, a connecting flange, 12, a sealing component, 13, a square tenon, 14, a straight line A, 15, a straight line B, 16, a straight line C, 17, a straight line D,18, a central line A, 19, a central line B, 20, a curve A, 21, a curve B, 22, a curve C, 23, a curve D, 24, a central line C, 25 and a central line D; 26. arc 27, end flow path cross section, 28, center flow path cross section.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

The present invention will be described in further detail with reference to the accompanying drawings.

Figures 1-5 show one embodiment of an elliptical flow passage plug valve with a uniform cross section of the invention, which comprises a valve body 1, a valve cover 3 arranged on the valve body 1 through a bolt component 2, a valve cavity 4 arranged in the valve body 1, a cock 5 which can be rotationally arranged in the valve cavity 4, a hand wheel 6 is arranged after the top of the cock 5 extends out of the valve cover 3, the valve body 1 comprises a left flow passage 7 and a right flow passage 8, the cock 5 is provided with a cock hole 9, the left flow passage 7, the tap hole 9 and the right flow passage 8 are communicated in sequence to form a fluid passage 10, the fluid passage 10 is arranged in bilateral symmetry, a central flow passage section 28 at the center of the fluid passage 10 is an ellipse, the end flow path cross-section 27 of the fluid passage 10 is circular, and the flow path cross-section of the fluid passage 10 gradually changes from the circular shape of the end flow path cross-section 27 to the elliptical shape of the center flow path cross-section 28.

Furthermore, the left end, the right end and the upper end of the valve body 1 are provided with connecting flanges 11.

Furthermore, the valve cavity 4 is a conical hole with a large upper part and a small lower part, the cock 5 is provided with an outer conical surface, and the outer conical surface of the cock 5 is matched with the valve cavity 4 to form a main sealing pair.

Furthermore, an annular groove is formed in the upper portion of the contact surface of the cock 5 and the valve body 1, a sealing component 12 is arranged in the annular groove, and auxiliary sealing pairs are formed among the sealing component 12, the valve body 1, the cock 5 and the valve cover 3.

Further, the sealing component 12 is annular, and the sealing component 12 is made of one or more materials selected from rubber, plastic, graphite, and metal.

Furthermore, a square hole is formed in the center of the bottom of the hand wheel 6, a square tenon 13 matched with the square hole is arranged at the top of the cock 5, and the square tenon 13 is inserted into the square hole and matched with the square hole, so that the square tenon is connected with the hand wheel 6 and transmits the torque of the hand wheel 6.

As an embodiment of the plug valve with an oval flow passage with a uniform cross section, the cross section of any flow passage on the fluid passage 10 has the same area.

Further, any flow passage section from the end to the center of the fluid passage 10 is elliptical,

the major axis radius of the ellipse on the section a of any flow channel on the fluid channel 10 is Y_aThe minor axis radius of the ellipse on any flow channel section a on the fluid channel 10 is Y ═ R + Xa · tan θ_b＝R²/(R+Xa·tanθ)；

Xa denotes a distance from an arbitrary flow path section a to the end flow path section 27 on the corresponding side;

setting the upper vertex of the central flow passage section 28 as a point N, the upper vertex of the end flow passage section 27 as a point G, and the straight line connecting the point G to the point N as a straight line GN, wherein theta is an included angle between the straight line GN and the central axis of the fluid flow passage;

r is the radius of the circle on the end flow channel cross section 27.

Further, let the circular area of the end flow passage section 27 be S₁＝πR²The elliptical area of any cross section on the fluid flow passage is S₂Then S is₂＝π·Y_a·Y_b＝π·(R+X·tanθ)·R²/(R+X·tanθ)＝πR²＝S₁。

The invention provides a plug valve with an oval flow passage with an equal section, which is characterized in that the central section of a fluid flow passage is designed to be oval, the end section of the fluid flow passage is designed to be round, and the flow passage section of a fluid passage 10 is ensured to be gradually changed from the round of the end section 27 of the flow passage to the oval of the central section 28 of the flow passage, so that the stress concentration effect can be greatly reduced, the strength and the rigidity of the flow passage are improved, and the material consumption is reduced; the uniform cross-section structure from the circular flow channel on the end face of the fluid flow channel to the elliptical flow channel in the center of the fluid flow channel can greatly reduce the fluid resistance and reduce the working energy consumption.

As an embodiment of the constant-section elliptical flow passage plug valve, a flow passage curve of the fluid flow passage comprises a connecting line of vertexes of a long axis of an ellipse on the section of the flow passage and a connecting line of vertexes of a short axis of the ellipse on the section of the flow passage; the long shaft vertex connecting line comprises a straight line A14, a straight line B15, a straight line C16 and a straight line D17, wherein the straight line A14, the straight line B15, the straight line C16 and the straight line D17 are symmetrically arranged by a central line A18, and the straight line A14, the straight line C16, the straight line B15 and the straight line D17 are symmetrically arranged by a central line B19; the straight line A and the straight line B, and the straight line C and the straight line D are respectively connected through corresponding arcs;

the short-axis vertex connecting line comprises a curve A20, a curve B21, a curve C22 and a curve D23, wherein the curve A20 and the curve B21, the curve C22 and the curve D23 are symmetrically arranged on a center line C24, and the curve A20 and the curve C22, the curve B21 and the curve D23 are symmetrically arranged on a center line D25.

In order to realize the production and manufacture of the plug valve with the oval flow channel with the uniform cross section, the invention also provides a method for drawing the flow channel curve of the fluid flow channel, which specifically comprises the following steps:

step 1, taking a line segment X5 on an X axis, wherein the length of the line segment X5 is equal to 1/2 of the total length of the fluid flow channel, and dividing the line segment X5 into 5 equal parts (or more equal parts) which are respectively marked as a dividing point A, a dividing point B, a dividing point C, a dividing point D and a dividing point E; drawing parallel lines of the Y axis respectively across the bisectors and labeled as line P1, line P2, line P3, line P4, line P5;

step 2, taking a point Yar on the Y axis, and marking the point Yar as a point G; taking Y at P5_a5The point of the distance from the highest point of the flow channel to the X-axis (the radius of the major axis of the ellipse on the center flow channel cross-section 28), is labeled as point N,

step 3, connecting point G and point N by using straight line, namely straight line GN, the straight line GN intersects line P1, line P2, line P3, line P4 at point H, point J, point K, point M, respectively; the heights of the point H, the point J, the point K, and the point M (the distances from the point H, the point J, the point K, and the point M to the X axis) are respectively marked as: y is_a1、Y_a2、Y_a3、Y_a4(ii) a The included angle between the straight line GN and the X axis is marked as theta; at this time, the major axis radius Y can be accurately measured_a1、Y_a2、Y_a3、Y_a4Or according to formula Y_aThe major semi-axis Y of the ellipse is calculated as R + X tan theta_a1、Y_a2、Y_a3、Y_a4、Y_a5A value of (d);

the straight line GN is transplanted to fig. 3, i.e., a connecting line from the end of the flow channel to the top of the long axis of the center of the flow channel, i.e., a straight line a 14; mirroring the straight line A14 along a center line A18 to obtain a straight line B15, mirroring the straight line A14 and the straight line B15 by a center line B19 to obtain a straight line C16 and a straight line D17; finally, the straight line A14 and the straight line B15, and the straight line C16 and the straight line D17 are respectively connected by using the corresponding arcs 26, and a complete and smooth connecting line of the vertexes of the long axes of the ellipses on the cross section of the runner can be obtained;

step 4, taking Y on the Y axis_b-R and is marked as point P,

step 5, using formula Y_b＝R²V (R + X tan. theta.) each Y was calculated_b1、Y_b2、Y_b3、Y_b4、Y_b5And according to Y_b1、Y_b2、Y_b3、Y_b4、Y_b5Respectively, take points on line P1, line P2, line P3, line P4, line P5, and mark as point S, point T, point V, point W, point Z; connecting the point P, the point S, the point T, the point V, the point W and the point Z by using a smooth curve to obtain a smooth curve PZ; transplanting the curve into the graph shown in FIG. 3 to obtain a long axis vertex connecting line from the end of the flow channel to the center of the flow channel, namely a curve A20;

step 6, mirroring the curve A20 along the center line C24 to obtain a curve B21; the curve a20 and the curve B21 are mirrored along the center line D25, resulting in a curve C22 and a curve D23;

step 7, connecting a curve A20 with a curve B21, and connecting a curve C22 with a curve D23 with connecting lines of vertexes of short axes of the ellipse of the cross section of the runner respectively;

step 8, in an XOY coordinate graph (see the detailed graph in FIG. 7), drawing a circle T0 by taking the point O as the center of a circle and the radius R as the radius, wherein the circle T0 intersects the X axis at a point P and intersects the Y axis at a point G;

step 9, taking the length of Y on the Y axis_a1、Y_a2、Y_a3、Y_a4、Y_a5The points of (a) are respectively a point H, a point J, a point K, a point M and a point N;

step 10, taking the length of Y on the X axis_b1、Y_b2、Y_b3、Y_b4、Y_b5The points of (1) are respectively a point S, a point T, a point V, a point W and a point Z;

step 11, taking the O point as the center of a circle, Y_a1、Y_a2、Y_a3、Y_a4、Y_a5Is a long semi-axis, Y_b1、Y_b2、Y_b3、Y_b4、Y_b5An ellipse T1, an ellipse T2, an ellipse T3, an ellipse T4 and an ellipse T5 can be obtained as a semi-minor axis;

step 12, sequentially connecting T0 with T1, T2, T3, T4 and T5 by smooth curved surfaces to obtain a left half-section flow channel model curved surface, and mirroring the left half-section flow channel model curved surface along the central flow channel section 28 to obtain a right half-section flow channel model curved surface;

further, the method also comprises a step 13 of modeling by using three-dimensional software (such as solidworks, CAXA entity design and Creo Direct) in order to obtain a relatively accurate model curved surface; and then, processing by using a numerical control machine tool to obtain an accurate three-dimensional solid model.

The embodiments described above are only preferred embodiments of the invention and are not exhaustive of the possible implementations of the invention. Any obvious modifications to the above would be obvious to those of ordinary skill in the art, but would not bring the invention so modified beyond the spirit and scope of the present invention.