JP2004076787A - Diaphragm valve structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a novel diaphragm valve structure hardly giving an abrupt pressure change to a fluid, suppressing the occurrence of cavitation and allowing smooth distribution of the fluid. <P>SOLUTION: A valve chest 20 is formed into an approximately funnel diameter-enlarged face 21 as a whole in a range from an orifice portion 15 approximate to an outer periphery 32 of a diaphragm portion 31. A valve seat 25 is formed into an obtuse-angle face 27 on the diameter-enlarged face. A valve element 35 is formed into a die shape 35S with a front side inclined face 37 adaptable to be seated on the valve seat and inclined toward the front end and a rear side inclined face 38 inclined toward a shaft portion 36 of the valve element. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a structure of a diaphragm valve used for controlling a fluid such as a chemical solution or pure water in a semiconductor manufacturing line or the like.
[0002]
[Prior art]
For example, in a semiconductor production line or a production line for various chemicals, the supply of various chemicals and pure water is controlled via a diaphragm valve. FIG. 10 of the accompanying drawings shows a generally used diaphragm valve 100 in which a diaphragm valve element 90 having a diaphragm section 91 and a valve element section 92 moves forward and backward with respect to a valve seat 105 in a valve chamber 102 of a valve body 101. Then, the flow of the fluid flowing out of the outflow portion 104 is controlled by opening and closing the orifice portion 103 of the valve chamber 102. Reference numeral 111 denotes an inflow side flow path of the fluid, and 112 denotes an outflow side flow path.
[0003]
In the drawing, reference numeral 80 denotes an operating cylinder device of the diaphragm valve body 90, 81 denotes a cylinder block, 82 denotes a cylinder chamber, 83 denotes a partition block that separates the cylinder chamber 82 from the valve chamber 102, and 84 denotes the diaphragm valve body. A piston member connected to 90, 85 and 86 are inflow / outflow portions of a working fluid for moving the piston member 84 forward and backward, 87 is a spring body for constantly urging the piston member 84 forward, 88 is an air vent portion, and 89 is a diaphragm valve. A mounting member for the body 90.
[0004]
In the illustrated diaphragm valve 100, an outflow portion 104 is formed on the side of the valve chamber 102, and an outflow side flow path 112 is provided continuously. According to the structure of the diaphragm valve 100, the fluid that has flowed into the valve chamber 102 from the inflow-side flow path 111 through the orifice portion 103 flows in the linear direction from the valve chamber 102 to the outflow-side flow path 112 through the outflow portion 104. I do. That is, the fluid flowing through the diaphragm valve 100 flows in an “L” shape having two locations of the bent portions R1 and R2.
[0005]
In the diaphragm valve 100 generally used in the related art, as shown in FIG. 11, a valve element 90 has a substantially horizontal front end surface 96 and a front portion inclined at an angle of approximately 45 degrees toward the end surface 96. The front-side inclined surface 97 can be seated on a valve seat 105 having a side inclined surface 97 and formed at a substantially right angle. Then, when the valve element 90 is retracted, the orifice portion 103 is opened, and the fluid flows into the valve chamber 102 from the orifice side flow path F11 via the diaphragm side flow path F12.
[0006]
However, in this diaphragm valve element 90, as shown in FIG. 12, the valve element 90 is retracted and the flow path between the front side inclined surface 97 and the valve seat 105 is slightly opened. In this case, since the valve body end surface 96 is substantially horizontal and the valve seat 105 is substantially right-angled, the fluid flows from the orifice-side flow path F11 through the flow path whose flow path width is sharply narrowed. . In addition, the fluid L12 that has passed through the valve seat 105 flows through the diaphragm-side flow path F12 in which the flow path width rapidly increases from the flow path with a narrow flow path width. When a fluid flows through such a flow path in which the flow path width changes rapidly, a sudden pressure change occurs in the fluid with the change in the flow path width.
[0007]
When a rapid pressure change occurs in the fluid, a cavitation phenomenon called so-called cavitation easily occurs. That is, cavitation is a phenomenon in which air contained in a liquid, which is a fluid, generates minute bubbles due to a decrease in pressure, and then evaporates and becomes hollow due to a sudden change in pressure. As described above, the cross-sectional area of the flow path between the valve seat 105 and the front inclined surface 97 of the valve body 90 is minimized at the valve seat 105 and greatly increases before and after the valve seat 105. Becomes maximum, and the pressure becomes minimum immediately after that, and cavitation occurs at this low pressure. The minute bubbles generated by the cavitation are disgusted as dust that contaminates the surface of the wafer in, for example, semiconductor manufacturing.
[0008]
Further, when the valve seat 105 as shown in the drawing is substantially perpendicular and the valve chamber 102 is formed by a vertical surface, the flow velocity of the fluid changes at those corners, and the pressure loss (energy loss) of the fluid is large. As a result, not only the flow efficiency is reduced, but also a portion where the fluid is difficult to flow is generated, so that there is a problem that the fluid replacement characteristic is deteriorated.
[0009]
Further, in the diaphragm valve 100 of this type, in addition to flowing the fluid from the orifice portion 103 side to the valve chamber 102 side, it is possible to reverse the flow direction and flow the fluid from the valve chamber 102 side to the orifice portion 103 side. is there. As shown in FIG. 13, when the fluid flows in the direction from the valve chamber 102 to the orifice portion 103 with the flow direction of the fluid reversed, cavitation is likely to occur as described above, and the pressure loss increases. In addition, the fluid replacement characteristics deteriorate.
[0010]
[Problems to be solved by the invention]
The present invention has been made in view of the above points, and provides a novel diaphragm valve structure that prevents a rapid change in pressure in a fluid, suppresses the occurrence of cavitation, and enables smooth flow of the fluid. The purpose is to do.
[0011]
[Means for Solving the Problems]
That is, the invention of claim 1 has a valve chamber (20) provided with a valve seat (25) via an orifice portion (15) in a flow path (F1, F2) of a controlled fluid, wherein the valve chamber is provided. A diaphragm valve body (30) integrally having a valve body (35) that advances and retreats with respect to the valve seat at a center part (33) of a diaphragm part (31) having an outer peripheral part (32) fixed thereto. In the valve (10), the valve chamber is formed on a surface (21) having a generally funnel-shaped diameter extending from the orifice portion to a substantially outer peripheral portion of the diaphragm portion, and the valve seat is provided with the valve seat. The valve body is formed on an obtuse angled surface (27) formed on a radial surface, and the valve body portion is seated on the valve seat and is inclined toward the front end. A rear side inclined surface (38) inclined toward the shaft portion (36). It is formed in frame shape (35S) that according to the diaphragm valve structure according to claim.
[0012]
The invention according to claim 2 relates to the diaphragm valve structure according to claim 1, wherein the valve seat comprises a fine ridge (26) formed on the top of the obtuse angle surface.
[0013]
The invention according to claim 3 relates to the diaphragm valve structure according to claim 1, wherein a fine ridge portion (39) seated on the valve seat is formed on a front-side inclined surface of the valve body portion.
[0014]
According to a fourth aspect of the present invention, the angle between the orifice-side flow path (F3) and the diaphragm-side flow path (F4) of the fluid formed by the obtuse surface and the front-side inclined surface of the valve body is substantially the same. The present invention relates to a diaphragm valve structure according to any one of claims 1 to 3.
[0015]
In the invention according to claim 5, the diaphragm portion is disposed so as to be inclined so that the center portion thereof is in the valve seat direction in advance, and even when the diaphragm valve body is retracted, the center portion of the diaphragm portion is higher than the outer peripheral portion thereof. The diaphragm valve structure according to any one of claims 1 to 4, wherein the diaphragm valve structure is configured not to move rearward.
[0016]
In the invention according to claim 6, the maximum outer diameter (r1) of the valve body is formed to be larger than the diameter distance (r2) at a position obtained by dividing the maximum diameter of the diaphragm film portion and the minimum diameter of the film portion of the diaphragm portion into two. The present invention relates to a diaphragm valve structure according to any one of claims 1 to 5.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.
1 is a longitudinal sectional view of the entire diaphragm valve according to one embodiment of the present invention, FIG. 2 is a longitudinal sectional view showing a state where the diaphragm valve body of FIG. 1 is retracted, and FIG. 3 is a front side inclination of the valve body part. FIG. 4 is an enlarged partial cross-sectional view showing the seat and the seating state of the valve seat. FIG. 4 is an enlarged partial cross-sectional view showing the seating state of the front-side inclined surface of the valve body and the valve seat according to another embodiment. FIG. 5 is a partial cross-sectional view showing the flow state of the fluid when the valve body is retracted, FIG. 6 is a partial cross-sectional view showing another flow state of the fluid, and FIG. 7 is the outer peripheral portion and the central portion of the diaphragm portion. 8 is a cross-sectional view showing the relationship between the valve body of the diaphragm valve body and the membrane of the diaphragm, and FIG. 9 is a cross-sectional view showing the embodiment using the structure of the present invention for a manifold valve. It is sectional drawing.
[0018]
1 and 2 are cross-sectional views of a diaphragm valve 10 according to the present invention. The illustrated diaphragm valve 10 includes a valve chamber 20 having a valve seat 25 via an orifice portion 15 in a flow path (inflow-side flow path F1 and outflow-side flow path F2) of a controlled fluid in a valve body 11; A diaphragm valve body 30 integrally having a valve body 35 which advances and retreats with respect to the valve seat 25 is provided at a central portion 33 of a diaphragm 31 having an outer peripheral portion 32 fixed to the valve chamber 20.
[0019]
The valve chamber 20 according to the structure of the present invention is formed on a surface 21 having a generally funnel-shaped enlarged diameter from the orifice portion 15 to a substantially outer peripheral portion 32 of the diaphragm portion, and the valve seat 25 is provided with the valve seat 25. The obtuse surface 27 is formed on the radial surface 21. At the same time, the valve body portion 35 has a front inclined surface 37 that can be seated on the valve seat 25 and is inclined toward the front end and a rear inclined surface 38 that is inclined toward the shaft portion 36 of the valve body portion 35. It is characterized by being formed in a piece shape 35S.
[0020]
1 and 2, reference numeral 50 denotes a known working cylinder device for operating the same diaphragm valve body 30 as described above, 51 denotes a cylinder block, 52 denotes a cylinder chamber, and 53 denotes the cylinder chamber 52 and the cylinder chamber 52. A partition block for partitioning the valve chamber 20, 54 is a piston member connected to the diaphragm valve body 30, 55 and 56 are inflow / outflow portions of a working fluid for moving the piston member 54 forward and backward, and 57 is a piston member that constantly moves the piston member 54 forward. A biasing spring body, 58 is an air vent portion, and 59 is a mounting member for the diaphragm valve body 30. FIG. 1 shows a state in which the diaphragm valve body 30 moves forward, the front inclined surface 37 of the valve body portion 35 is seated on the valve seat 25 and the valve is closed, and FIG. A state in which the fluid is retracted by the operation of the device 50 and the fluid flows through the valve chamber 20 is shown. Hereinafter, the diaphragm valve 10 will be described in detail.
[0021]
First, as shown in the figure, the valve chamber 20 is formed on a surface 21 having a generally funnel-shaped enlarged diameter from the orifice portion 15 to the diaphragm portion outer peripheral portion 32 as a whole. The funnel shape refers to an inclined shape in which the front side is narrow and the rear side is gradually widened, and here, the bottom surface portion of the valve chamber 20 having the orifice portion 15 and the wall surface portion of the valve chamber 20 to which the diaphragm outer peripheral portion 32 is fixed. The curved surface 22 is smoothly connected without any intervening corners, and is formed on the surface 21 whose diameter is expanded to reach the outer peripheral portion 32 of the diaphragm portion. The valve seat 25 is formed on an obtuse angle surface 27 formed on the enlarged diameter surface 21.
[0022]
As described above, by forming the shape of the valve chamber 20 on the surface 21 having a generally funnel-shaped enlarged diameter from the orifice portion 15 to the substantially outer peripheral portion 32 of the diaphragm portion, the corners of the valve chamber 20 are eliminated. Thus, the flow velocity of the fluid flowing through the valve chamber 20 can be made uniform. Therefore, this makes it possible to suppress the pressure loss of the fluid and improve the flow efficiency, and the fluid replacement characteristics are improved by the smooth flow.
[0023]
On the other hand, the valve body portion 35 of the diaphragm valve body 30 has a front inclined surface 37 that can be seated on the valve seat 25 and is inclined toward the front end and a rear side inclined toward the shaft portion 36 of the valve body portion 35. A piece 35S having an inclined surface 38 is formed. The front-side inclined surface 37 and the rear-side inclined surface 38 are preferably formed as long as possible. Desirably, the front-side inclined surface 37 is formed up to the tip of the valve body 35 as shown in the figure, and the rear-side inclined surface is formed. The surface 38 is formed up to the shaft portion 36. Reference numeral 40 in the figure denotes a backing member for the diaphragm portion 31.
[0024]
As described above, by forming the valve body portion 35 into a piece shape 35S having the front side inclined surface 37 and the rear side inclined surface 38, the pressure balance between the primary side pressure and the secondary side pressure applied to the valve body portion 35 is improved. Therefore, the operation of the valve body 30 can be performed with a smaller force. Further, since the pressure balance between the primary pressure and the secondary pressure applied to the valve body 35 can be achieved, the orifice size can be increased, and the flow rate can be increased without increasing the outer size of the diaphragm valve 10. Can be shed. Further, by forming the valve body portion 35 into the bridge shape 35S, the fluid flowing through the valve chamber 20 flows all the way along the bridge shape 35 of the valve body portion 35, and effectively mixes and flushes the fluid. be able to.
[0025]
In the example of FIGS. 1 and 2, as shown in the enlarged view of FIG. 3, the valve seat 25 is formed on the top of the obtuse angle surface 27 formed on the enlarged diameter surface 21 as shown in the enlarged view of FIG. 3. An example composed of the ridges 26 is shown. The ridge 26 is for ensuring the seating of the valve body 35 to the valve seat 25. In order to ensure this seating property, the valve seat 25 is seated on the front-side inclined surface 37 of the valve body 35 as defined in the third aspect of the invention and illustrated in the enlarged view of FIG. Fine projections 39 may be formed.
[0026]
As understood from FIGS. 3 and 4, in the structure of the present invention, the valve seat 25 formed on the obtuse angle surface 27 of the funnel-shaped enlarged surface 21 of the valve chamber 20 and the front-side inclined surface 37 of the valve body 35 are provided. Thus, in the flow path from the orifice portion 15 to the valve chamber 20, an orifice-side flow path F3 that narrows at an acute angle and a diaphragm-side flow path F4 that widens at an acute angle are formed. The flow of the fluid L1 flowing through the valve seat 25 when the valve body 30 is retracted and the fluid flows as shown in FIG. 5 by the acute angled orifice side flow path F3 and the diaphragm side flow path F4. The road width gradually narrows and widens before and after the valve seat 25, and it is possible to avoid a sudden change. That is, a large pressure change of the fluid before and after the valve seat 25 can be avoided. This can prevent the generation of minute bubbles due to the cavitation described above. Also, as shown in FIG. 6, the same effect is obtained when the flow direction of the fluid L2 is reversed.
[0027]
As shown in FIGS. 3 and 4, the orifice-side flow path F <b> 3 of the fluid formed by the obtuse angled surface 27 and the front-side inclined surface 37 of the valve body 35. By configuring the angle of the diaphragm-side flow path F4 to be substantially the same, the flow path width gradually narrowing and gradually widening before and after the valve seat 25 becomes symmetrical, so that the pressure change can be avoided more effectively. it can.
[0028]
FIG. 7 shows the positional relationship between the outer peripheral portion 32 of the diaphragm portion 31 and the central portion 33 of the diaphragm valve element 30. As shown in each figure of FIG. 7 and defined as the invention of claim 5, the diaphragm portion 31 is previously arranged so as to be inclined such that the center portion 33 thereof is directed toward the valve seat 25 (see FIG. 7A). The configuration is such that the central portion 33 of the diaphragm portion 31 does not move rearward of the outer peripheral portion 32 even when the diaphragm valve element 30 is retracted (see reference numeral A2 in FIG. 7B).
[0029]
With such an arrangement of the diaphragm valve body 30, the center part 33 of the diaphragm part 31 is located forward (A2 position) of the outer peripheral part 32 when the valve body 30 retreats, so that the center part 33 of the diaphragm part 31 is always positioned. It becomes a shape arrangement protruding into the valve chamber 20. As a result, no recess is formed in the center portion 33 of the diaphragm portion 31, and as can be clearly understood from each of FIGS. 7A and 7B, the rear inclined surface 38 of the valve body portion 35 and the enlarged surface 21 of the valve chamber 20. Thus, a ring-shaped space having a substantially triangular cross section is formed in the valve chamber 20, and the flow of fluid in the valve chamber 20 becomes smooth throughout. Therefore, bubbles hardly accumulate in the diaphragm portion 31, pressure loss is reduced, and fluid replacement characteristics are improved.
[0030]
Further, the displacement of the diaphragm portion 31 accompanying the movement of the valve element 30 is only in one direction (downward) on the valve seat 25 side with the outer peripheral portion 32 as a fulcrum. The bending fatigue applied to the outer peripheral portion 32 of the base 31 can be reduced, and its durability can be enhanced. Further, by arranging the central portion 33 of the diaphragm portion 31 forward of the outer peripheral portion 32 when the valve body is retracted, flushing or the like can be effectively performed.
[0031]
FIG. 8 shows that the maximum outer diameter r1 of the valve body portion 35 of the diaphragm valve body 30 is defined by dividing the maximum diameter and the minimum diameter of the diaphragm film portion 34 of the diaphragm portion 31 by two as defined in the invention of claim 6. Represents an example in which it is formed to be larger than the diameter distance r2 at the position indicated. As described above, by forming the piece 35S having the front side inclined surface 37 and the rear side inclined surface 38 on the valve body 35, the pressure of the primary side pressure and the secondary side pressure applied to the valve body 35 is increased. Although the balance can be achieved and the valve body 30 can be operated with a smaller force, the maximum outer diameter r1 of the valve body portion 35 is set to be equal to the maximum diameter of the diaphragm film portion 34 of the diaphragm portion 31 and the maximum diameter of the film portion. In the case where the diameter is larger than the diameter distance r2 at the position where the small diameter is divided into two, the force in the valve closing direction acts on the valve body 35 even when the pressure from the secondary side is high. , The opening and closing of the valve body 30 can be performed smoothly. Note that the diaphragm film portion 34 is a thin film portion that is displaced by pressure. Thus, even at a high pressure, it is possible to use the fluid from either the orifice-side flow path or the diaphragm-side flow path without specifying the inlet of the fluid. In a normal case, when a fluid is introduced from the diaphragm-side flow path, the valve body is lifted upward by the pressure applied to the diaphragm portion, so that it has been difficult to increase the pressure resistance.
[0032]
The structure of the diaphragm valve 10 of the present invention configured as described above can be used as a manifold valve M, for example, as shown in FIG. The manifold valve M connects a plurality (three in this case) of the diaphragm valve portions 10A, 10B, and 10C according to the present invention to each other in the lateral direction by flow paths 72 and 73, and connects the manifold valve M from the flow path 71 of the diaphragm valve section 10A. It is configured to flow through the flow paths 72 and 73 to the flow path 74 of the diaphragm valve portion 10C in a penetrating manner. In the illustrated manifold valve M, the valve body 79 is shown as a single unit. However, independent individual diaphragm valve portions are generally connected as needed.
[0033]
The flow of the fluids L12, L13, L14 from the inflow portions 12A, 12B, 12C of the respective diaphragm valve portions 10A, 10B, 10C is controlled by the respective diaphragm valve bodies 30A, 30B, 30C, and the fluid from the flow path 71 is controlled. It mixes with L15 and flows out of the flow path 74 as a mixed fluid L16. This is used for mixing chemicals. Alternatively, flushing may be performed by flowing a clean liquid such as pure water as the fluid L15 from the flow path 71 in a state where the diaphragm valve bodies 30A, 30B, and 30C are closed as shown in the figure.
[0034]
The diaphragm valve structure according to the present invention is capable of effectively performing liquid mixing, flushing, and the like in such a manifold valve M by the unique action possessed by each component described above.
[0035]
【The invention's effect】
As shown and described above, according to the diaphragm valve structure of the present invention, first, the flow velocity of the fluid flowing through the valve chamber can be made uniform by the shape of the valve chamber, and the pressure loss of the fluid is suppressed while the flow rate is reduced. Efficiency can be improved and fluid replacement characteristics are improved by smooth flow. Also, depending on the shape of the valve body, the pressure balance between the primary pressure and the secondary pressure can be achieved, the orifice size can be increased, and the flow rate can be increased without increasing the outer diameter of the diaphragm valve. In addition, the fluid can be circulated around the valve body and can be effectively mixed and flushed.
[0036]
Further, according to the structure of the present invention, the flow passage that gradually narrows and widens at an acute angle is formed by the valve seat and the valve body of the valve chamber, so that a large pressure change of the fluid flowing before and after the valve seat is reduced. This can prevent the generation of minute bubbles due to cavitation.
[0037]
In addition, according to the second and third aspects of the present invention, the seating of the valve seat and the valve body in the valve chamber is ensured, and according to the fourth aspect of the present invention, the flow of the fluid flowing before and after the valve seat is ensured. Pressure changes can be avoided more effectively.
[0038]
According to the fifth aspect of the present invention, in terms of the arrangement of the diaphragm valve element, the flow of the fluid in the valve chamber becomes smoother and smoother, bubbles are less likely to accumulate in the diaphragm, the pressure loss is reduced, and the fluid replacement characteristic is reduced. Also improve. At the same time, bending fatigue applied to the outer peripheral portion of the diaphragm can be reduced, and durability can be improved.
[0039]
Furthermore, according to the invention of claim 6, the valve body can be smoothly opened and closed even when the pressure resistance is increased, and even when the pressure is high, the orifice side flow path can be specified without specifying the fluid inlet. Alternatively, it can be used from any of the diaphragm side flow paths.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of an entire diaphragm valve according to an embodiment of the present invention.
FIG. 2 is a longitudinal sectional view showing a state where the diaphragm valve body of FIG. 1 is retracted.
FIG. 3 is an enlarged partial cross-sectional view showing a front inclined surface of a valve body and a seated state of a valve seat.
FIG. 4 is an enlarged partial cross-sectional view of a seating state of another embodiment of a front-side inclined surface of a valve body and a valve seat.
FIG. 5 is a partial cross-sectional view illustrating a flow state of a fluid when the valve body retreats.
FIG. 6 is a partial sectional view showing another flow state of the fluid.
FIG. 7 is a cross-sectional view illustrating a positional relationship between an outer peripheral portion and a central portion of a diaphragm portion.
FIG. 8 is a cross-sectional view illustrating a relationship between a valve body portion of a diaphragm valve body and a membrane portion of the diaphragm portion.
FIG. 9 is a sectional view of an embodiment in which the structure of the present invention is used for a manifold valve.
FIG. 10 is a longitudinal sectional view of a conventional general diaphragm valve.
FIG. 11 is a sectional view of a main part of a conventional diaphragm valve.
FIG. 12 is a cross-sectional view illustrating a flow state of a fluid in a conventional diaphragm valve.
FIG. 13 is a cross-sectional view illustrating another flow state of a fluid in a conventional diaphragm valve.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Diaphragm valve 15 Orifice part 20 Valve chamber 21 (roof-shaped) enlarged-diameter surface 25 Valve seat 26 Protrusion part 27 Diaphragm surface 30 Diaphragm valve element 31 Diaphragm part 32 Outer peripheral part 33 Center part 34 Diaphragm film part 35 Valve part 35S piece Shape 37 Front-side inclined surface 38 Rear-side inclined surface 39 Ridge 50 Working cylinder device F3 Orifice-side flow path F4 Diaphragm-side flow path

Claims (6)

A diaphragm section (31) having a valve chamber (20) provided with a valve seat (25) through an orifice section (15) in a flow path of a controlled fluid, and having an outer peripheral portion (32) fixed to the valve chamber. A) a diaphragm valve (10) including a diaphragm valve body (30) integrally having a valve body part (35) that advances and retreats with respect to the valve seat at a central part (33) of the diaphragm valve (10);
The valve chamber is formed on a surface (21) having a generally funnel-shaped enlarged diameter from the orifice portion to a substantially outer peripheral portion of the diaphragm portion, and the valve seat is formed on the enlarged-diameter surface. The valve body is formed on an obtuse angled surface (27), and the valve body has a front-side inclined surface (37) that can be seated on the valve seat and is inclined toward the front end and a shaft (36) of the valve body. A diaphragm valve structure characterized by being formed in a bridge shape (35S) having a rear-side inclined surface (38) inclined toward the rear surface. The diaphragm valve structure according to claim 1, wherein the valve seat comprises a fine ridge (26) formed on the top of the obtuse surface. 2. The diaphragm valve structure according to claim 1, wherein a fine ridge portion (39) seated on the valve seat is formed on a front-side inclined surface of the valve body portion. 3. 4. The fluid flow path according to claim 1, wherein the oblique surface and the front-side inclined surface of the valve body have substantially the same angle between the orifice-side flow path (F3) and the diaphragm-side flow path (F4). The diaphragm valve structure according to claim 1. The diaphragm portion is arranged so that the center portion thereof is inclined in advance so that the center portion thereof is in the valve seat direction, so that the center portion of the diaphragm portion does not move rearward from the outer peripheral portion even when the diaphragm valve body retreats. The diaphragm valve structure according to any one of claims 1 to 4, wherein: 6. The valve according to claim 1, wherein a maximum outer diameter (r1) of the valve portion is larger than a diameter distance (r2) at a position obtained by dividing a maximum diameter of the diaphragm film portion and a minimum diameter of the film portion of the diaphragm portion into two. The diaphragm valve structure according to claim 1.

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