JP2009121547A - Diaphragm valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a diaphragm valve increasing a flow rate while maintaining a compact structure and reducing a pressure loss of fluid flowing in the valve. <P>SOLUTION: The diaphragm valve comprises: a body 1 provided with a first flow path 4 and a second flow path 5 respectively extending from an inlet port 2 and an outlet port 3 in flow path axis directions, an opening part 12 formed in a top surface and communicating with the first flow path and the second flow path, and a partition wall 10 extending from bottom surfaces of the first flow path 4 and second flow path 5 towards the opening part 12 and formed in a top portion with a valve seat 11; a bonnet 18 attached to the top surface of the body 1; a diaphragm 15 dispose do to cover the opening part 12 and caught at a peripheral edge between the body 1 and the bonnet 18; and a drive part for driving the diaphragm. Opposite sides of the partition wall are formed of: concave curved faces 8, 9 extending from the bottom surfaces of the first flow path and second flow path to inflexion points; and convex curved faces 6, 7 extending from the inflexion points to the valve seat 11. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a diaphragm valve used in various industries such as a chemical factory, semiconductor manufacturing field, liquid crystal manufacturing field, and food field. More specifically, the present invention relates to a fluid flowing through the valve while maintaining a compact structure. The present invention relates to a diaphragm valve that can reduce pressure loss and increase flow rate.

  Conventionally, there has been a diaphragm valve as shown in FIG. 4 as a diaphragm valve used in various industries (see, for example, Patent Document 1). In such a diaphragm, the valve main body 101 is provided with a first flow path 104, a second flow path 105, and a wear portion 106 positioned between the two flow paths. On the valve main body 101, the valve main body 101 is provided. The bonnet 110 is mounted on the diaphragm mounting seat 109 so as to sandwich the periphery of the diaphragm 108. A sleeve 111 having an internal thread on the inner surface is rotatably attached to the upper portion of the bonnet 110 so that the valve stem 112 can be screwed up and down with the sleeve 111. A pressing body 113 was attached, and the central portion of the diaphragm 108 was fixed to the pressing body 113. Further, a concave shape is formed from the valve seat surface 107 toward the first opening 102 and the second opening 103 between the bottom surface of the first flow path 104 and the second flow path 105 and the valve seat surface 107 formed at the top of the wear portion. The first concave curved surface 117 and the second concave curved surface 118 are respectively connected to each other.

JP-A-8-121618

  However, the flow path of the diaphragm valve has a shape in which a large flow rate is difficult to flow. When the fluid flowing from the first opening 102 and flowing through the first flow path 104 flows along the first concave curved surface 117, the fluid rises upward and flows obliquely upward, and gets over the valve seat surface 107. Then, it is separated from the valve seat surface 107 and collides with the diaphragm 108, thereby changing the flow direction and flowing into the second flow path 105 side (see the arrow in FIG. 4). However, when the fluid collides with the diaphragm 108 and the flow direction is forcibly changed in this way, the smooth flow of the fluid is hindered and a pressure loss occurs. In addition, since the fluid flowing through the first flow path 104 flows linearly from the first opening 102, there is a tendency that the fluid flows in the direction of the first concave curved surface 117 near the wear portion due to its inertia. In the vicinity of the contact portion between the valve body 101 and the diaphragm 108 located downstream of the first intersecting portion 115 where the inner peripheral surface of the opening 114 formed on the upper surface of the first passage 104 intersects the ceiling surface of the first flow path 104. , The flow rate decreases and the fluid tends to stay. As a result, a turbulent flow X that flows back to the staying portion from the boundary between the staying portion and the fluidizing portion is generated, causing a pressure loss.

  Next, since the fluid that has flowed into the second flow path 105 collides with the diaphragm 108 and changes its flow direction, it cannot flow along the second concave curved surface 118, and the opening 114 There is a tendency that the inner circumferential surface and the ceiling surface of the second flow path 105 are biased toward the second intersecting portion 116 side. Thereby, the flow rate decreases on the second concave curved surface 118 side, and the fluid tends to stay. As a result, a turbulent flow Y that flows backward from the boundary between the staying portion and the flow portion to the staying portion is generated, causing a pressure loss.

  In addition, the fluid that flows biased toward the second intersecting portion 116 flows toward the bottom surface side of the second channel 105 after the flow passage area is reduced by the second intersecting portion 116. Thereby, the flow rate decreases on the ceiling surface side of the second flow path 105 downstream from the second intersecting portion 116 and the fluid tends to stay. As a result, a turbulent flow Z that flows back to the staying portion from the boundary between the staying portion and the fluidizing portion is generated, causing a pressure loss. Then, the fluid that has passed through the diaphragm valve flows out from the second opening 103.

  As described above, the pressure loss caused by the fluid colliding with the diaphragm 108 and the pressure loss caused by the turbulent flow X, Y, Z generated in various places cause the fluid passing through the valve body 101 to have a pressure loss. There was a problem that the flow rate was remarkably reduced due to the hindered flow.

  On the other hand, in order to suppress generation | occurrence | production of the turbulent flow X and Z, the method of providing a taper in the 1st intersection part 115 and the 2nd intersection part 116 can be taken. However, even if the turbulent flow can be reduced only by providing a taper in the conventional flow path, the generation of the turbulent flows X and Z cannot be prevented. Further, in the method in which the first intersecting portion 115 and the second intersecting portion 116 are tapered, the generation of the turbulent flow Y cannot be reduced or prevented, and the fluid is generated by colliding with the diaphragm 108. Since the pressure loss cannot be improved, it is not sufficient to provide the first intersection 115 and the second intersection 116 with a taper.

  Further, in order to suppress the generation of turbulent flow Y and the collision of the fluid with the diaphragm 108, the first channel 104 extends between the bottom surface of the first channel 104 and the second channel 105 and the valve seat surface at the top of the wear unit. A method of reducing the rising angle of the concave curved surface 117 and the second concave curved surface 118 can be used. However, if the rising angle of the first flow path 104 and the second flow path 105 is reduced and the flow path is formed while maintaining the height position of the valve seat surface 107, the distance between the valve surfaces is increased in accordance with the rising angle. The problem that the valve becomes large, the flow passage areas of the first flow passage 104 and the second flow passage 105 in the first intersection portion 115 and the second intersection portion 116 are reduced, and the obtained effect is offset. As a result, there arises a problem that the flow rate becomes small.

  Furthermore, in order to increase the flow rate, a method of increasing the flow rate by increasing the flow path area by enlarging the opening 114 can be used. However, by increasing the size of the opening 114, the width and space between the valve body 101 and the bonnet 110 become larger, and the valve itself becomes larger, so that the workability when installing the valve in a narrow space such as the inside of the apparatus is increased. The problem is that the operability is remarkably deteriorated, and that the diaphragm 108 is enlarged along with the increase in the area of the opening 114, thereby increasing the load on the diaphragm 108 with respect to the fluid internal pressure and shortening the life of the valve. Occurs. Further, when the wall thickness is increased in order to reinforce the diaphragm 108, the response characteristic of the diaphragm 108 is deteriorated particularly in the case of an air-driven or electrically-driven diaphragm valve.

  In addition, a method of increasing the flow rate by lowering the height position of the valve seat surface 107 to reduce the height difference from the flow passage and increasing the flow passage area between the valve seat surface 107 and the diaphragm 108 is also adopted. obtain. However, when the position of the valve seat surface 107 is lowered, the opening / closing stroke of the diaphragm 108 increases, the deformation amount of the diaphragm 108 when the valve is opened / closed increases, and bending fatigue and expansion / contraction fatigue of the diaphragm 108 increase. As a result, there arises a problem that the durability of the diaphragm 108 is lowered and the life of the diaphragm 108 is shortened or easily damaged. In particular, in a specification with a large number of opening / closing operations such as a pneumatically driven or electrically driven diaphragm valve, a decrease in durability of the diaphragm 108 leads to shortening of the life of the valve.

  The present invention has been made in view of the above-described problems of the prior art, and provides a diaphragm valve that can increase the flow rate while maintaining a compact structure and can reduce the pressure loss of fluid flowing in the valve. The purpose is to provide.

  In order to solve the above-described problems, the present invention forms a first flow path and a second flow path extending in the flow path axial direction from an inlet and an outlet formed on two opposing side surfaces, respectively, on the top surface. An opening communicating with the first flow path and the second flow path, a partition wall extending from the bottom surface of the first flow path and the second flow path toward the opening, and having a valve seat formed at the top. A main body provided; a bonnet attached to the top surface of the main body; a diaphragm disposed to cover the opening of the main body and having a peripheral edge sandwiched between the main body and the bonnet; A diaphragm for driving the diaphragm, wherein the diaphragm is pressed against and separated from the valve seat by the driver, and the valve seat formed at the upper end of the partition wall and the first 1 style And both sides of the partition wall connecting the bottom surface of the second flow path extend from the bottom surfaces of the first flow path and the second flow path to the inflection point, and the valve seat from the inflection point. A diaphragm valve is provided that includes a convex curved surface that extends to the surface.

  In the diaphragm valve, it is preferable that a chamfered portion is provided at an intersection between the inner peripheral surface of the opening and the ceiling surface of the first flow path and the second flow path.

  Moreover, it is preferable that the angle of the chamfered portion is 15 to 30 ° with respect to the flow path axis, and the dimension in the height direction of the chamfered portion is 2 mm or more.

  Moreover, it is preferable that the inclination angle of the side surface of the partition wall at the inflection point is 45 ° or less with respect to the flow path axis.

  Further, it is preferable that an inter-surface dimension L of the diaphragm valve and an inner diameter D of the opening are determined so as to satisfy a relationship of L ≦ 3D + 95 (mm).

  Preferably, the convex curved surface and the concave curved surface are formed in an arc shape, and the radius of the convex curved surface is determined to be smaller than the radius of the concave curved surface.

In the above case, it is more preferable that the radius R ₁ of the convex curved surface and the radius R ₂ of the concave curved surface are determined so as to satisfy a relationship of 1.0R ₁ <R ₂ ≦ 1.5R _1. .

  Moreover, it is preferable that surface roughness Ra of the internal peripheral surface of the said 1st flow path and the said 2nd flow path is 6.3 micrometers or less.

  The driving unit may be a manual type, an air driving type, or an electric driving type.

Since the present invention is configured as described above, the following excellent effects can be obtained.
(1) A convex curved surface and a concave curved surface are continuously formed and connected between the bottom surface of the first flow path and the second flow path and the valve seat so that the fluid flows over the valve seat. It can flow along the bottom surface of the road, preventing the collision of the fluid with the diaphragm and the generation of turbulent flow from the second convex curved surface to the vicinity of the second concave curved surface, thereby reducing pressure loss. .
(2) The first flow path and the second flow path are provided by providing chamfered portions at the intersections between the inner peripheral surface of the opening formed on the top surface of the valve body and the ceiling surface of the first flow path and the second flow path. The flow direction of the fluid flowing in the first flow path and the second flow path can be guided in the flow path axis direction.
(3) A convex curved surface and a concave curved surface are continuously formed and connected between the bottom surface of the first flow channel and the second flow channel and the valve seat, and formed on the top surface of the valve body. By providing a chamfered portion at the intersection of the inner peripheral surface of the opening and the ceiling surface of the first channel and the second channel, the occurrence of turbulent flow downstream of the chamfered portion is prevented and pressure loss is reduced. The fluid can flow smoothly without waste due to the synergistic effect, and the flow rate can be increased due to the significant reduction in pressure loss.
(4) In addition, the above configuration increases the flow rate while maintaining a compact shape without lowering the position of the valve seat surface, increasing the opening on the top surface of the main body, or widening the space between the surfaces. Can be made.
(5) Furthermore, the load caused by the fluid applied to the diaphragm can be reduced.

  Hereinafter, although an embodiment of the present invention is described with reference to drawings, it cannot be overemphasized that the present invention is not limited to this embodiment.

  FIG. 1 is a longitudinal sectional view of a diaphragm valve showing a first embodiment of the present invention. FIG. 2 is an enlarged vertical cross-sectional view of the main part of FIG. FIG. 3 is a partial sectional view showing an air-driven diaphragm valve.

First, the configuration of the diaphragm valve according to the embodiment of the present invention will be described with reference to FIGS. 1 and 2. The diaphragm includes a valve body 1, a diaphragm 15, a compressor 17, a bonnet 18, a stem 21, and a handle 23. The valve body 1 is made of polyvinyl chloride (hereinafter referred to as PVC), and the inter-surface dimension L is 210 mm, and the inner diameter D of the first opening 2 and the second opening 3 is 50 mm. The valve body 1 includes a first opening formed on one of the opposing side surfaces of the valve body 1, that is, the first flow path 4 extending in the flow axis direction from the inlet 2, and the other of the opposing side surfaces of the valve body. A second flow path 5 extending in the flow path direction from the formed second opening, that is, the outflow port 3, and a partition wall 10 positioned between the first flow path 4 and the second flow path 5 are provided. An opening 12 that communicates with the first flow path 4 and the second flow path 5 is provided on the top surface of the valve body 1. The partition wall 10 extends from the bottom surfaces of the first flow path 4 and the second flow path 5 toward the opening 12, and a valve seat 11 to which the diaphragm 15 is pressed and separated is formed at the top. Further, the side surface of the partition wall 10 that connects the valve seat 11 formed on the top of the partition wall 10 and the portion of the bottom surface of the first flow path 4 that extends in parallel with the flow path axis extends from the valve seat 11 to the first flow path. And a first convex curved surface 6 that extends in a convex shape toward the bottom surface of 4 and a first concave curved surface 8 that continuously curves and extends in a concave shape and is connected to the bottom surface of the first flow path 4. It forms part of the bottom surface of the first flow path 4. Similarly, the side surface of the partition wall 10 that connects the valve seat 11 and the portion of the bottom surface of the second flow channel 5 that extends in parallel with the flow channel axis is directed from the valve seat 11 toward the bottom surface of the second flow channel 5. The second convex curved surface 7 that is curved and extends in a convex shape and the second concave curved surface 9 that is curved and concavely extended continuously and connected to the bottom surface of the second flow path 5 are provided. A part of the bottom surface of the two flow paths 5 is formed. The inclination angles A and A ′ of the side walls of the partition wall 10 on the first flow path 4 and the second flow path 5 side are both 45 ° with respect to the flow path axis. The first convex curved surface 6, the first concave curved surface 8, the second convex curved surface 7 and the second concave curved surface 9 are all arcuate in the longitudinal section of FIG. radius R ₂ of the radius R ₁ and the first concave curved surface 8 and the second concave curved surface 9 of the Jo curved surface 6 and a second convex curved surface 7 is defined such that R ₂ = 1.3R ₁ .

  Here, the inclination angle A on the side surface of the partition wall 10 on the first flow path 4 side and the inclination angle A ′ on the second flow path 5 side transition from the first convex curved surface 6 to the first concave curved surface 8. It means the angle formed by the inflection point and the tangent at the inflection point where the second convex curved surface 7 transitions to the second concave curved surface 9 with respect to the flow path axis. In the above embodiment, the inclination angles A and A ′ are both 45 °, but are not necessarily limited to this angle. However, the inclination angles A and A ′ are 45 ° or less downward with respect to the flow path axis when the direction from the valve center to the respective opening side is 0 ° with respect to the flow path axis. Desirably, 40 to 45 ° is more desirable. When the inclination angles A and A ′ are set to 45 ° or less, the fluid flow vector has a larger component in the flow path axis direction than in the direction perpendicular to the flow path axis. As the fluid flows in the direction of the flow path axis along the valve seat 11 when getting over 11, the fluid is less likely to collide with the diaphragm 15, and the fluid is second convex when flowing into the second flow path 5 side. It becomes easy to flow along the curved surface 7, and the fluid flows also on the second convex curved surface 7 side and the second concave curved surface 9 side of the second flow path 5 to suppress the occurrence of turbulent flow. Therefore, the inclination angles A and A ′ are desirably 45 ° or less with respect to the flow path axis. Moreover, in order to form the flow path of the valve body 1 under suitable conditions without enlarging the valve, the angle is preferably 40 ° or more.

  The dimension L between the faces of the diaphragm valve means the length in the flow path axis direction between the opposing side surfaces of the valve body 1 in which the first opening 2 and the second opening 3 are respectively provided. In the embodiment described above, the inter-surface dimension L is 210 mm, and the inner diameter D of the first opening 2 and the second opening 3 is 50 mm. Of course, this is not a limitation. However, the inter-plane dimension L of the diaphragm valve and the inner diameter D of the first opening 2 and the second opening 3 are preferably in a relationship of L ≦ 3D + 95 (mm), and in a relationship of 3D + 50 ≦ L ≦ 3D + 95 (mm). More desirably. In order not to increase the rising angle of the flow path while maintaining the height of the valve seat 11, 3D + 50 ≦ L (mm) is good, and the distance between the surfaces is reduced while maintaining the fluid flow smoothly. In order not to increase the diaphragm valve, L ≦ 3D + 95 (mm) is preferable.

In the above embodiment, the radius R ₁ of the first convexly curved surface 6 and a second convex curved surface 7 and a radius R ₂ of the first concave curved surface 8 and the second concave curved surface 9 is R ₂ = 1. Although it is described that it is determined to be 3R ₁ , it is not limited to this. However, the radius R ₁ of the first convexly curved surface 6 and a second convex curved surface 7 and a radius R ₂ of the first concave curved surface 8 and the second concave curved surface 9, 1.0R ₁ <R ₂ ≦ 1 .5R ₁ is desirable. When R ₁ is larger than R ₂ , it is easy to guide the direction of fluid flow in the direction of the flow axis when the fluid passes over the valve seat 11, but on the other hand, the flow area tends to be narrowed. When R ₂ is larger than 1.5 times R ₁ , the inclination angle of the side wall of the partition wall 11 on the first flow path 4 side and the second flow path 5 side becomes large, and the flow of fluid is relative to the flow path axis. The force toward the vertical direction becomes stronger. From these facts, in order to guide the flow direction of the fluid in the direction of the flow path axis and not reduce the flow path area, the radius R _{1 of} the first convex curved surface 6 and the second convex curved surface 7 and the first The radius R ₂ of the one concave curved surface 8 and the second concave curved surface 9 is preferably 1.0R ₁ <R ₂ ≦ 1.5R ₁ .

  Furthermore, the surface roughness Ra of the inner peripheral surfaces of the first flow path 4 and the second flow path 5 of the valve body 1 is desirably 6.3 μm or less so that the fluid flows more smoothly on the flow path bottom surface. The lower limit of the surface roughness Ra is preferably as low as possible, but it is preferably 0.1 μm or more so as not to impair the moldability of the valve body 1 and make it difficult to handle parts.

  A first chamfered portion 13 is formed at the intersection of the inner peripheral surface of the opening 12 formed on the upper surface of the valve body 1 and the ceiling surface of the first flow path 4. The first chamfered portion 13 is provided such that the dimension H in the height direction is 3 mm and the chamfer angle B is 20 ° with respect to the flow path axis. Similarly, a second chamfered portion 14 is formed at the intersection between the inner peripheral surface of the opening 12 and the ceiling surface of the second flow path 5, and the second chamfered portion 14 has a height dimension H. The chamfering angle B ′ is 3 mm, and the chamfering angle B ′ is 20 ° with respect to the flow path axis.

  Here, the chamfered portion refers to an intersection between the inner peripheral surface of the opening 12 formed on the upper surface of the valve body 1 and the ceiling surface of the first flow path 4 and the second flow path 5 (the first intersection 115 in FIG. 4). , Refer to the chamfered portion formed at the second intersecting portion 116). By providing the first chamfered portion 13 and the second chamfered portion 14 in the first flow path 4 and the second flow path 5 of the valve body 1 as the chamfered portions, the flow area of the first flow path 4 and the second flow path 5 respectively. In addition, the fluid resistance in the flow path of the valve can be reduced by inducing the flow direction of the fluid in the flow path axis direction. In the above embodiment, the chamfering angles B and B ′ are both determined to be 20 ° with respect to the flow path axis, but are not limited thereto. However, the chamfering angle B of the first chamfered portion 13 and the chamfered angle B ′ of the second chamfered portion 14 are set so that the direction from each nearest opening to the center side of the valve is 0 ° with respect to the flow path axis. Further, it is preferably 15 to 30 ° on the opening 12 side with respect to the flow path axis, and more preferably 18 to 22 °. The chamfer angles B and B ′ of the first chamfered portion 13 and the second chamfered portion 14 are 15 ° or more in order to increase the flow channel area and to obtain the effect of guiding the direction of fluid flow in the flow channel axial direction. In order to guide the direction of fluid flow so as not to be perpendicular to the flow path axis, 30 ° or less is preferable.

  Further, as shown in FIG. 2, the dimension in the height direction of the chamfered portion is, in the case of the first chamfered portion 13, the flow path axis from the ridge line 26 on the first flow path 4 side to the ridge line 27 on the opening 12 side. Is the height in the vertical direction (the portion of dimension H in FIG. 2). In the said embodiment, although the dimension H of the height direction of the 1st chamfer part 13 and the 2nd chamfer part 14 is 3 mm, it is not limited to this. However, the dimension H in the height direction of the first chamfered portion 13 and the second chamfered portion 14 is desirably 2 mm or more, and more desirably 2 to 5 mm. In order to increase the flow area in the vicinity of the first chamfered portion 13 and the second chamfered portion 14 and increase the flow rate, the height dimension H should be 2 mm or more, and the seal between the valve body 1 and the bonnet 18 is good. The dimension H in the height direction is preferably 5 mm or less in order to maintain the thickness of the periphery of the opening 12 of the valve body 1 at a certain level or more so as to maintain good performance.

  The diaphragm 15 is made of ethylene propylene rubber (hereinafter referred to as EPDM). An embedded fitting 16 is embedded in the center of the diaphragm 15 on the non-wetted surface side so that the upper portion protrudes, and the diaphragm 15 is engaged with the compressor 17 driven by the driving portion in the vertical direction by the embedded fitting 16. It is fixed. The peripheral edge of the diaphragm 15 is sandwiched between the valve body 1 and the bonnet 18, and is crushed around the opening 12 on the upper surface of the valve body 1 by the lower surface of the bonnet 18 and fixed in a watertight state.

  In the above embodiment, the material of the diaphragm 15 is EPDM, but is not limited to this. However, the material of the diaphragm 15 is preferably a rubber-like elastic body, and EPDM, isoprene rubber, chloroprene rubber, chlorosulfonated rubber, nitrile rubber, styrene butadiene rubber, chlorinated polyethylene, fluorine rubber, etc. are suitable materials. Can be mentioned. The material of the diaphragm 15 is polypropylene (hereinafter referred to as PP), polyvinylidene fluoride (hereinafter referred to as PVDF), polytetrafluoroethylene (hereinafter referred to as PTFE), and tetrafluoroethylene / perfluoroalkyl vinyl ether. It may be a resin such as a polymer (hereinafter referred to as PFA), and is not particularly limited. Further, a high-strength reinforcing cloth may be inserted into the diaphragm 15, and the reinforcing cloth is preferably made of nylon (in the case of fluororubber, made of polyvinylidene fluoride). This is suitable for preventing deformation and breakage of the diaphragm 15 when fluid pressure is applied to the diaphragm 15 when the valve is closed.

  The compressor 17 is made of PVDF, and the upper portion of the compressor 17 is engaged and fixed to the lower end portion of the stem 21. The bonnet 18 is made of PVC, and is fixed to the upper part of the valve body 1 with bolts and nuts (not shown). A copper alloy sleeve 20 is supported in a through hole 19 in the upper center of the bonnet 18. The stem 21 is made of a copper alloy and is screwed with a female screw portion 22 provided inside the sleeve 20. The handle 23 is made of PP, is fitted to the upper outer peripheral portion of the sleeve 20, and is disposed at the upper end portion of the bonnet 18.

  In the above embodiment, both the valve body 1 and the bonnet 18 are made of PVC. However, the material of the valve body 1 and the bonnet 18 of the diaphragm valve is PVC, polystyrene, ABS resin, Any of resin such as PP, PVDF, PTFE, PFA, polychlorotrifluoroethylene, metal such as iron, copper, copper alloy, brass, aluminum, and stainless steel, or ceramic such as porcelain may be used. In particular, a resin diaphragm valve having excellent corrosion resistance is preferably used for a chemical solution piping line. In the above embodiment, the material of the compressor 17 is PVDF. However, the material is not particularly limited to this, and may be resin or metal, but is preferably resin such as PVDF. Moreover, in the said embodiment, although the material of both the stem 21 and the sleeve 20 is made of a copper alloy, it is not particularly limited to this, and the material of the stem 21 and the sleeve 20 is a material having an intended strength. Any metal such as iron, copper, copper alloy, brass, aluminum, and stainless steel is preferable.

  In the above embodiment, the compressor 17, the sleeve 20, and the handle 23 fixed to the stem 21 constitute a drive unit for driving the diaphragm 15 in the vertical direction. As described above, in the above embodiment, the drive unit of the diaphragm 15 is a manual type, but is not limited to the manual type, and may be an air driven type by air pressure, an electric drive type by a motor, etc. It is not limited. In the case of the air drive type, as shown in FIG. 3, the pneumatic drive unit 24 is replaced with the handle 23 of the diaphragm valve, and similarly in the case of the electric drive type, the electric drive unit (motor etc.) An automatic diaphragm valve is formed by engagement with the stem 25 (not shown).

  Furthermore, in the present invention, the connection between the diaphragm valve and the pipe may be any of socket connection, screw connection, flange connection, butt connection, or cap nut connection, and is not particularly limited.

  Next, the operation at the time of opening and closing the diaphragm valve of the present embodiment will be described with reference to FIG.

  When the handle 23 is rotated in the closing direction (clockwise) from the fully opened state of FIG. 1, the stem 21 and the compressor 17 provided at the lower end of the stem 21 are lowered according to the rotation of the handle 23, and the diaphragm 15 is gradually moved accordingly. It curves downward, and finally comes into pressure contact with the valve seat 11 on the top surface of the partition wall 10 of the valve body 1. As a result, the first flow path 4 and the second flow path 5 are closed, and the diaphragm valve is fully closed.

  Next, when the handle 23 is rotated in the opening direction (counterclockwise), the stem 21 and the compressor 17 provided at the lower end of the stem 21 are raised according to the rotation of the handle 23, and accordingly the diaphragm 15 is moved to the valve seat 11. , And gradually curves upward and rises to the open limit position. As a result, the first flow path 4 and the second flow path 5 are opened, and the diaphragm valve is fully opened (the state shown in FIG. 1).

  Next, the flow of fluid when the diaphragm valve of the present embodiment is fully opened will be described with reference to FIG.

  In FIG. 1, the fluid flowing through the diaphragm valve flows in from the first opening 2 and rises obliquely upward (upper right direction in FIG. 1) along the first concave curved surface 8 of the first flow path 4. When the first convex curved surface 6 is reached, the flow rising obliquely upward at the first concave curved surface 8 gradually changes its direction along the first convex curved surface 6 in the direction of the channel axis (the right direction in FIG. 1). ) And flows into the second flow path 5 along the valve seat 11. Since the fluid that has reached the valve seat 11 flows in the direction of the flow path axis, the fluid flows smoothly along the bottom surface of the flow path and flows along the liquid contact surface of the diaphragm 15. Therefore, the flow of the fluid colliding with the diaphragm 15 is suppressed, the load due to the fluid applied to the diaphragm 15 can be reduced, and the pressure loss due to the fluid colliding with the diaphragm 15 can be suppressed.

  Further, by providing the first chamfered portion 13 at the intersection between the inner peripheral surface of the opening 12 and the ceiling surface of the first flow path 4, the flow area of the first flow path 4 around the intersection is increased, and the partition The direction of the flow of the fluid rising obliquely upward with respect to the wall 10 can be guided in the direction of the flow path axis so that the fluid reaching the valve seat 11 can easily flow in the direction of the flow path axis. Further, when the angle formed by the first chamfered portion 13 with respect to the flow path axis is set to 15 to 30 °, the flow of the fluid rising along the first concave curved surface 8 can be gradually directed in the flow path axis direction. In addition, it is possible to reduce stagnation near the periphery of the diaphragm. Furthermore, by combining the side surface of the partition wall 10 in which the convex curved surface and the concave curved surface are continuously formed as a part of the bottom surface of the first flow path 4 and the first chamfered portion 13, In the flow path in the vicinity of the contact portion between the diaphragm 15 and the valve body 1 located on the downstream side of the intersection between the surface and the ceiling surface of the first flow path 4, it is difficult for the fluid to stay as in the conventional case. Generation of partial turbulence (turbulent flow X in FIG. 4) can be prevented, and pressure loss due to turbulent flow can be suppressed.

  Next, the fluid that has flowed into the second flow path 5 along the valve seat 11 flows along the second convex curved surface 7 and gradually changes the direction of the flow that has been directed to the flow path axis direction downward. . Since the bottom surface of the second flow path 5 in the vicinity of the valve seat 11 (that is, the side surface of the partition wall 11) is a convex curved surface, the fluid changes its flow gently downward along the second convex curved surface 7. As in the prior art, the fluid flow is not biased toward the second chamfered portion 14. Subsequently, when the fluid reaches the second concave curved surface 9 from the second convex curved surface 7, the flow directed downward by the second convex curved surface 7 gently flows along the second concave curved surface 9. In the direction of the flow path axis, and flows out from the second opening 3 to the outside. In this way, the fluid that has flowed into the second flow path 5 flows along the bottom surface of the second flow path 5, so that the fluid in the vicinity of the second convex curved surface 7 and the second concave curved surface 9. As a result, the stagnation of the turbulent flow in the stagnation portion (turbulent flow Y in FIG. 4) can be prevented and the pressure loss due to the turbulent flow can be suppressed.

  Further, by providing the second chamfered portion 14 at the intersection between the inner peripheral surface of the opening 12 and the ceiling surface of the second flow path 5, the flow area of the second flow path 5 around the intersection is increased. In addition, the fluid flowing downward along the second convex curved surface 7 can be guided in the direction of the flow path axis so that the fluid flowing in the second flow path 5 is not biased. Further, when the angle formed by the second chamfered portion 14 with respect to the flow path axis is set to 15 to 30 °, the flow of fluid in the flow path axis direction along the valve seat 11 together with the effect of the second convex curved surface 7. Then, the flow of the fluid can be gently directed in the direction of the flow axis along with the effect of the second concave curved surface 9. Furthermore, the second chamfered portion and the bottom surface portion of the second flow path 4 in which the convex curved surface and the concave curved surface are continuously formed (that is, the side surface of the partition wall 10) and the second chamfered portion 14 are provided together. The fluid stays on the ceiling surface side of the second flow path 105 downstream from the chamfered portion 14, and the turbulent flow (turbulent flow Z in FIG. 4) is prevented from occurring in the staying portion. Loss can be suppressed.

  In addition, when the flow from the first flow path 4 passes through the valve seat 11, the flow direction is the flow path axial direction so that the fluid flowing through the second flow path 5 flows smoothly without waste. The shape of the bottom surface portion (that is, the side surface of the partition wall 10) connecting the bottom surface portion parallel to the flow channel axis of the first flow channel 4 and the second flow channel 5 and the valve seat 11 is both convex and curved. The curved surface needs to be formed continuously, and is preferably symmetrical.

  As described above, in the diaphragm valve of the present invention, the fluid flowing into the first opening 2 gently changes the flow direction along the first concave curved surface 8 and the first convex curved surface 6 of the first flow path 4. When the valve seat 11 is reached, the fluid flows along the valve seat 11 and turns in the direction of the flow path axis, and the fluid flowing into the second flow path 5 side is the second convex curved surface 7 and the second concave shape. The flow direction is gently changed along the curved surface 9. Therefore, the collision with the diaphragm 15 and the occurrence of turbulent flow in the vicinity of the second convex curved surface 7 to the second concave curved surface 9 are prevented, and the pressure loss in the flow path is suppressed to flow out from the second opening 3. (See arrow in FIG. 1). Further, by providing the first chamfered portion 13 and the second chamfered portion 14, it is possible to increase the flow channel area around the intersection and to guide the direction of the fluid flowing through the flow channel to the flow channel axial direction. it can. Further, the bottom surface of the flow channel (the portion connecting the bottom surface portion of the flow channel extending in parallel with the flow channel axis and the valve seat 11) in which the convex curved surface and the concave curved surface are continuously formed is combined with the chamfered portion. Turbulent flow on the downstream side of the first chamfered portion 13 and the second chamfered portion 14 can be prevented, and fluid can be smoothly flowed without waste due to a synergistic effect. The flow rate can be increased by the reduction. In addition, the diaphragm valve of the present invention can increase the flow rate while maintaining the compact shape of the conventional valve body without changing the face-to-face or width of the valve body 1.

  Next, with respect to the diaphragm valve in the present invention, the side surface of the partition wall 10 of the valve body 1 (the bottom surface portion extending in parallel with the channel axis of the bottom surfaces of the first channel 4 and the second channel 5 and the valve seat 11) A plurality of three-dimensional models in which the shape of the connecting portion) and the shapes of the first chamfered portion 13 and the second chamfered portion 14 were changed were created, and the flow rate analysis of the fluid flowing through the diaphragm valve was performed. The analysis method is shown below.

[Flow analysis by 3D model]
Using 3D thermal fluid analysis software STAR-LT (made by Cd. Adapco Japan Co., Ltd.), water at 20 ° C is applied to the 3D model of the diaphragm valve with the valve opening fully open. Analyzing the flow rate when flowing from the first opening of the valve body at a constant flow velocity (1.0 m / s) and flowing out from the second opening, the difference between the pressure at the first opening and the pressure at the second opening Evaluation was performed by calculating the Cv value from the pressure and the flow rate.

[Example 1]
Referring to FIG. 1, the inter-surface dimension L is 210 mm, the inner diameter D of the first opening 2 and the second opening 3 is 50 mm, the radius R _{1 of} the first convex curved surface 6 and the second convex curved surface 7 and the first The radius R _{2 of the} one concave curved surface 8 and the second concave curved surface 9 is set to be R ₂ = 0.8R ₁ , and at the intersection of the opening 12 and the first flow path 4 and the second flow path 5. A flow rate analysis was performed using a three-dimensional model of a diaphragm valve in the case where the valve main body 1 without a chamfered portion was used. The results are shown in Table 1.

[Example 2]
A flow rate analysis was performed using a three-dimensional model of a diaphragm valve in the case where the valve body 1 in which the radius R ₁ and the radius R _{2 of} Example 1 were set so that R ₂ = 1.0R ₁ was used. The results are shown in Table 1.

[Example 3]
A flow rate analysis was performed using a three-dimensional model of a diaphragm valve in the case where the valve body 1 in which the radius R ₁ and the radius R _{2 of} Example 1 were set so that R ₂ = 1.3R ₁ was used. The results are shown in Table 1.

[Example 4]
A flow rate analysis was performed using a three-dimensional model of a diaphragm valve in the case where the valve body 1 in which the radius R ₁ and the radius R _{2 of} Example 1 were set so that R ₂ = 1.5R ₁ was used. The results are shown in Table 1.

[Example 5]
A flow rate analysis was performed using a three-dimensional model of a diaphragm valve when the valve body 1 in which the radius R ₁ and the radius R _{2 of} Example 1 were set so that R ₂ = 1.7R ₁ was used. The results are shown in Table 1.

[Example 6]
In Example 2, the 1st chamfering part 13 and the 2nd chamfering part 14 are provided in the intersection part of the opening part 12, and the 1st flow path 4 and the 2nd flow path 5, and both angle B and B 'of this chamfering part are provided. The flow rate analysis was performed using a three-dimensional model of a diaphragm valve in the case of using the valve body 1 set so that the dimension H in the height direction of the chamfered portion is 3 mm with respect to the flow path axis. . The results are shown in Table 1.

[Example 7]
The flow rate analysis was performed using the three-dimensional model of the diaphragm valve when using the valve body 1 in which the radius R ₁ and the radius R _{2 of} Example 6 were set so that R ₂ = 1.3R ₁ . The results are shown in Table 1.

[Example 8]
The flow rate analysis was performed using the three-dimensional model of the diaphragm valve when the valve body 1 in which the radius R ₁ and the radius R _{2 of} Example 6 were set so that R ₂ = 1.5R ₁ was used. The results are shown in Table 1.

[Example 9]
In Example 6, the radius R ₁ and the radius R ₂ are set to be R ₂ = 1.3R ₁ , the angles B and B ′ of the chamfered portions are 45 ° with respect to the flow path axis, and the height of the chamfered portions is set. A flow analysis was performed using a three-dimensional model of a diaphragm valve in the case where the valve main body 1 set so that the dimension H in the direction was 3 mm was used. The results are shown in Table 1.

[Comparative Example 1]
The part which connects the valve seat and the part which extends in parallel with the flow path axis line among the bottom surfaces of the first flow path and the second flow path as in the diaphragm valve of FIG. A flow analysis was performed using a three-dimensional model of a diaphragm valve in the case of using a valve body formed only by a concave curved surface curved in a concave shape. The results are shown in Table 1.

[Comparative Example 2]
A first chamfered portion and a second chamfered portion are provided at the intersection between the inner peripheral surface of the opening of Comparative Example 1 and the ceiling surface of the first flow channel and the second flow channel, and the angles B and B ′ of the chamfered portions are In both cases, a flow analysis was performed using a three-dimensional model of a diaphragm valve when using a valve body set so that the dimension H in the height direction of the chamfered portion was 3 mm with respect to the flow path axis. . The results are shown in Table 1.

[Comparative Example 3]
A first chamfered portion and a second chamfered portion are provided at the intersection between the inner peripheral surface of the opening of Comparative Example 1 and the ceiling surface of the first flow channel and the second flow channel, and the angles B and B ′ of the chamfered portions are In both cases, a flow analysis was performed using a three-dimensional model of a diaphragm valve when using a valve body set so that the dimension H in the height direction of the chamfered portion was 3 mm with respect to the flow path axis. . The results are shown in Table 1.

  In Table 1, the rate of increase of the Cv value is calculated by calculating the rate of increase of the Cv value with respect to the comparative example 1 using the conventional diaphragm valve shape (see FIG. 4). When Examples 1-5 are compared with Comparative Example 1, it can be seen that the Cv value of each Example is increased by about 4.0 to 10.0% with respect to the Cv value of Comparative Example 1. This is a convex curved surface and a concave shape curved convexly from the valve seat 11 toward the first opening 2 and the second opening 3 on the bottom surfaces of the first flow path 4 and the second flow path 5 of Examples 1 to 5. By forming the concave curved surface continuously curved, the fluid flowing through the first flow path 4 and the second flow path 5 smoothly flows along the bottom surfaces of the flow paths 4 and 5 and gets over the valve seat 11. Since the fluid sometimes flows in the direction of the flow path axis, the collision of the fluid with the diaphragm 15 and the generation of turbulent flow on the second convex curved surface 7 (turbulent flow Y in FIG. 4) are prevented. , Pressure loss can be suppressed. As a result, the Cv value is increased with respect to Comparative Example 1.

  Next, comparing Comparative Examples 1 to 3, it can be seen that the Cv values of Comparative Examples 2 and 3 are increased by about 9.0 to 12.0% with respect to the Cv value of Comparative Example 1. In Comparative Example 2 and Comparative Example 3, the first chamfered portion 13 and the second chamfered portion 14 are provided at the intersection between the upper opening 12 of the valve body 1 and the first flow path 4 and the second flow path 5. This is because the opening area of the flow path in the vicinity of the valve seat becomes large and the fluid easily flows and the Cv value increases. It should be noted that the generation of turbulent flow can be reduced to some extent only by providing a chamfered portion, but it is not possible to prevent turbulent flow itself.

  When Examples 2-4 and Examples 6-8 are compared with Comparative Example 1 and Comparative Example 2, Examples 6-8 show that the bottom surface shape of the first channel 4 and the second channel 5 is a convex curved surface. It is formed by a concave curved surface, and a chamfered portion is provided at the intersection of the opening 12 and the first flow path 4 and the second flow path 5, and the increase rate of the Cv values in Examples 6 to 8 is In addition, Examples 2 to 4, which are increased by about 21.0 to 32.0% with respect to the Cv value of Comparative Example 1, and in which the bottom surface shape of the flow path is formed by a convex curved surface and a concave curved surface, It has increased more than the value which added each Cv value of Comparative Examples 1-2 which only provided the chamfering part in the crossing part. This prevents the generation of turbulent flow (turbulent flow X, Z in FIG. 4) by combining the configuration of the bottom surface shape of the flow path composed of the convex curved surface and the concave curved surface and the chamfered portion, This is because the fluid can flow smoothly without waste due to the synergistic effect of the above structure, and as a result, the pressure loss of the flow path is reduced and the Cv value is increased.

When Examples 1-8 are compared with each other, the radius R _{1 of} the first convex curved surface 6 and the second convex curved surface 7 and the first concave curved surface 8 and the second concave curved surface 9 are obtained from Examples 1-5. in the relationship between the radius R _2, the increasing rate of the Cv value is larger is when the R _1> R _2, in particular as the maximum rate of increase Cv value when R ₂ = 1.3R _{1, 1} It can be seen that the increase rate of the Cv value becomes larger in the range of 0.0R ₁ <R ₂ ≦ 1.5R ₁ . Also, from Examples 6-8, the relationship between the radius R ₁ and radius R ₂ is, as the maximum rate of increase in Cv value when _{R 2 = 1.3R 1, 1.0R 1} <R 2 ≦ 1.5R It can be seen that the increase rate of the Cv value similarly increases in the range of ₁ .

  Moreover, when Example 7 and Example 9 are compared with Comparative Example 2 and Comparative Example 3, the increase rate of the Cv value is larger because the angles B and B ′ of the first chamfered portion 13 and the second chamfered portion 14 are larger. It can be seen that at 20 °, the flow direction of the fluid is smoothly directed in the direction of the flow path axis, and the flow rate characteristics are improved. When the angles B and B ′ are around 20 °, the increase rate of the Cv value is large, and 15 to 30 ° is preferable.

  Next, the diaphragm valves of Example 3, Example 7, Comparative Example 1 and Comparative Example 2 analyzed for the flow rate using a three-dimensional model were actually molded, and the actual flow rate was measured using the molded diaphragm valve. The measuring method is shown below.

[Cv value analysis method by actual flow]
Based on JIS B 2005-2-3 “Industrial Process Control Valves—Part 2: Capacity of Flow—Section 3: Test Procedure”, a diaphragm valve was piped in an atmosphere of 23 ° C. ± 2 ° C. Evaluated by measuring the differential pressure between the pressure taps on the first channel side and the second channel side, the flow rate per fixed time, and the temperature of the water, and calculating the Cv value by actually flowing water at ℃ ± 2 ° C Went.

[Example 10]
Using the diaphragm valve (R ₂ = 1.3R ₁ , no chamfered portion) molded based on Example 3, the flow rate was measured by an actual flow, and the Cv value was calculated. The results are shown in Table 2.

[Example 11]
Using a diaphragm valve molded according to Example 7 (R ₂ = 1.3R ₁ , chamfered portion 20 °), the flow rate was measured by an actual flow, and the Cv value was calculated. The results are shown in Table 2.

[Comparative Example 4]
Using a diaphragm valve (conventional flow path, no chamfered portion) molded based on Comparative Example 1, the flow rate was measured by an actual flow, and the Cv value was calculated. The results are shown in Table 2.

[Comparative Example 5]
Using a diaphragm valve molded according to Comparative Example 2 (conventional flow path, chamfered portion 20 °), the flow rate was measured by an actual flow, and the Cv value was calculated. The results are shown in Table 2.

  In Table 2, the increase rate of the Cv value is obtained by calculating the increase rate of the Cv value with respect to the other comparative example 4 using the shape of the conventional diaphragm valve (see FIG. 4). When Example 10 and Comparative Example 4 are compared, it can be seen that the Cv value of Example 10 is increased by 11.9% with respect to the Cv value of Comparative Example 4. Although the result was slightly better than the Cv value increase rate of 9.5% with respect to Comparative Example 1 of Example 2 obtained by the three-dimensional flow rate analysis, the same tendency was obtained as the tendency.

  Next, comparing Comparative Examples 4 and 5, it can be seen that the Cv value of Comparative Example 5 is increased by 13.4% with respect to the Cv value of Comparative Example 4. Although the result was slightly better than the Cv value increase rate of 11.5% for Comparative Example 1 of Comparative Example 2 obtained by the three-dimensional flow analysis, the same tendency was obtained as the tendency.

  Next, when Example 11 and Comparative Example 4 are compared, the Cv value of Example 11 is increased by about 35.0% with respect to the Cv value of Comparative Example 4, similarly to the result obtained by the three-dimensional flow analysis. I understand that Although the result was slightly better than the Cv value increase rate of 31.4% with respect to Comparative Example 1 of Example 7 obtained by the three-dimensional flow rate analysis, the same tendency was obtained as the tendency.

  As described above, the same results as in the three-dimensional flow analysis were obtained with the actually molded diaphragm valve. Therefore, according to the diaphragm valve of the present invention, the occurrence of turbulent flow is prevented in the flow path, the fluid can flow smoothly without waste, and the flow rate is increased by greatly reducing the pressure loss. I can see that

It is a longitudinal cross-sectional view of the diaphragm valve which shows 1st embodiment of this invention. It is a principal part expanded longitudinal cross-sectional view of FIG. It is a fragmentary sectional view showing an air drive type diaphragm valve. It is a longitudinal cross-sectional view which shows the conventional diaphragm valve.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Valve body 2 1st opening 3 2nd opening 4 1st flow path 5 2nd flow path 6 1st convex curved surface 7 2nd convex curved surface 8 1st concave curved surface 9 2nd concave curved surface 10 Partition wall 11 Valve seat 12 Opening portion 13 First chamfered portion 14 Second chamfered portion 15 Diaphragm 16 Embedded metal fitting 17 Compressor 18 Bonnet 19 Through hole 20 Sleeve 21 Stem 22 Female screw portion 23 Handle 24 Pneumatic drive unit 25 Stem 26 Ridge line 27 Ridge line

Claims (9)

A first channel and a second channel extending in the channel axis direction from an inlet and an outlet formed on two opposing side surfaces, respectively, and a first channel and a second channel formed on the top surface A main body provided with a partition wall extending from the bottom surface of the first flow path and the second flow path toward the opening and having a valve seat formed at the top, and attached to the top surface of the main body; A bonnet provided, a diaphragm disposed to cover the opening of the main body and having a peripheral edge sandwiched between the main body and the bonnet, and a drive unit for driving the diaphragm, In the diaphragm valve in which the diaphragm is pressed against and separated from the valve seat by the drive unit,
Both side surfaces of the partition wall connecting the valve seat formed at the upper end of the partition wall and the bottom surfaces of the first channel and the second channel are bottom surfaces of the first channel and the second channel. A diaphragm valve comprising: a concave curved surface extending from the inflection point to the inflection point; and a convex curved surface extending from the inflection point to the valve seat.   2. The diaphragm valve according to claim 1, wherein a chamfered portion is provided at an intersection between an inner peripheral surface of the opening and a ceiling surface of the first flow path and the second flow path.   The diaphragm valve according to claim 2, wherein an angle of the chamfered portion is 15 to 30 ° with respect to a flow path axis, and a dimension in the height direction of the chamfered portion is 2 mm or more.   The diaphragm valve according to any one of claims 1 to 3, wherein an inclination angle of a side surface of the partition wall at the inflection point is 45 ° or less with respect to a flow path axis.   5. The diaphragm valve according to claim 1, wherein an inter-surface dimension L of the diaphragm valve and an inner diameter D of the opening are determined so as to satisfy a relationship of L ≦ 3D + 95 (mm). .   The convex curved surface and the concave curved surface are formed in an arc shape, and the radius of the convex curved surface is determined to be smaller than the radius of the concave curved surface. The diaphragm valve according to any one of 5. The diaphragm according to claim 6, wherein a radius R ₁ of the convex curved surface and a radius R ₂ of the concave curved surface are determined so as to satisfy a relationship of 1.0R ₁ <R ₂ ≦ 1.5R _1. valve.   The diaphragm valve according to any one of claims 1 to 7, wherein a surface roughness Ra of inner peripheral surfaces of the first flow path and the second flow path is 6.3 µm or less.   The diaphragm valve according to any one of claims 1 to 8, wherein the driving unit is a manual type, an air driving type, or an electric driving type.

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