JP2010144765A - Diaphragm valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a diaphragm valve inhibiting fluid from flowing out of portions other than a leak flow passage when a valve is closed and easily changing minute flow rate when the valve is closed. <P>SOLUTION: This diaphragm valve includes a valve box 11 forming a flow-in passage 11a and a flow-out passage 11b and having a valve chamber 11c formed in a middle of the passage, a valve seat collar 12 as a thick wall cylindrical body valve seat reinforcement member surrounding a flow-in passage outlet edge part opening at a bottom wall of the valve chamber 11c, a resin valve seat 13 fitted and retained in such a manner that a part projects from the valve seat collar 12, a diaphragm 15 closing/opening by approaching to/separating from a projection part of the valve seat 13, and a seat ring 14 as a press member pressing at least the valve seat collar 12 toward a bottom wall of the valve chamber 11c, and has the leak flow passage 20 providing communication between the flow-in passage 11a and the flow-out passage 11b, and an annular rib 12a projecting from a contact surface with the bottom wall of the valve chamber 11c, both being formed on the valve seat collar 12. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention is a leak that is arranged in a path of various fluid supply systems or discharge systems used when products are manufactured by various manufacturing apparatuses such as a semiconductor manufacturing apparatus and a liquid crystal manufacturing apparatus, and allows a desired small flow rate of fluid to flow when the valve is closed. The present invention relates to a diaphragm valve having a valve seat structure.

Japanese Patent Laid-Open No. 08-014415 Japanese Patent Laid-Open No. 10-026240 Japanese Utility Model Publication No. 05-050254 Japanese Patent Laid-Open No. 07-027253

  Conventionally, in a manufacturing apparatus for manufacturing various products such as semiconductors and liquid crystals, a purge gas (for example, an inert gas such as nitrogen gas or argon gas) in a gas piping system of an ultra-high purity gas used in a manufacturing line. Diaphragm valves such as bleed valves and block valves are well known in the case where the flow is continued.

  FIG. 4 shows an example of a gas piping system of ultra-high purity gas in a production line using such a semiconductor manufacturing apparatus, a liquid crystal manufacturing apparatus, or the like (see, for example, Patent Document 1).

  In the gas piping system shown in FIG. 4, when the gas cylinder 100 is replaced, if the gas cylinder 100 is removed with the corrosive gas remaining in the line, the corrosive gas reacts with moisture in the atmosphere. However, this causes corrosion of lines and components.

  Therefore, in order to prevent such corrosion, the piping system is purged with the purge gas when the gas cylinder 100 is removed.

  In the illustrated example, nitrogen gas is used as the purge gas. Here, the nitrogen gas is used as a vacuum generation (exhaust) gas for the vacuum generator 140 and is not used for sealing in the line. The purge described above is performed by repeatedly filling the nitrogen gas into the line and evacuating the line through the generation of a vacuum using the nitrogen gas.

  In FIG. 4, 111 to 117 are stop valves, 121 and 122 are needle valves, 131 to 134 are check valves, 151 and 152 are filters, 161 and 162 are pressure gauges, and 170 is a pressure regulator.

  Here, a vacuum generator 140 is used as a vacuum generation source during evacuation.

  The vacuum generator 140 utilizes the property (ejector effect) in which the flow rate of the fluid (nitrogen gas) is increased inside the nozzle and the fluid is drawn by generating a negative pressure near the nozzle outlet. Further, the presence of the check valves 131 and 132 prevents the corrosive gas from flowing back into the line from the vent line without flowing nitrogen gas, but the corrosive gas reaches the vacuum generator 140. .

  For this reason, there is a possibility that troubles such as nozzle clogging due to the corrosion of the nozzle of the vacuum generator 140 may occur.

  Therefore, when evacuation is not performed, that is, when the stop valve 111 is closed, the stop valve 112 is opened and the flow rate is reduced by maintaining the needle valve 121 at a predetermined opening degree. Nitrogen gas is always supplied at a constant flow rate.

  In this way, a certain amount of nitrogen gas is circulated through the gas piping system, and the inflow of gas from the vent line is prevented.

  However, in such a configuration using a plurality of valves, there is a problem that the number of parts increases and the cost increases.

  Therefore, as shown in FIG. 5 to FIG. 8, as a measure for preventing gas inflow from such a vent line, a technique in which the primary side and the secondary side that are in a closed state are always in communication with each other through a constant flow gas circulation hole. Is known (see, for example, Patent Documents 1 to 4).

  FIG. 5 shows an example of a diaphragm valve provided with such a constant flow gas circulation hole (see Patent Documents 1 and 2). 1 forms an inflow path 1a and an outflow path 1b, and a valve in the middle of the path. A valve box 2 having a chamber 1c, 2 is a cylindrical valve seat collar having an annular flange 2a surrounding an outlet edge of an inflow passage 1a that opens to the bottom wall of the valve chamber 1c, and 3 is fitted on the outer periphery of the valve seat collar 2 The valve seat 4, which is held together and has a height higher than the valve seat collar 2, is circumferentially engaged with the outer peripheral step portion of the valve seat 3, and a plurality of flow holes 4a communicating with the outflow passage 1b are equally spaced. The seat ring 5 is a diaphragm that is pressed and adhered to the valve seat 3, and 6 is a diaphragm presser that supports the outer peripheral edge of the upper surface side of the diaphragm 5 and presses the outer peripheral edge of the lower surface thereof toward the upper surface near the outer periphery of the seat ring 4, 7 closes the space above the valve chamber 1c and pushes the diaphragm. Tighten the 6 fixed to the bonnet, 8 is a pressing piece for pressing contact of the central portion of the diaphragm 5 into the valve seat 3 by to driving of the driving unit 9 through the center portion of the hood 7.

  Further, a leak flow passage 10 is provided between the valve seat collar 2 and the valve chamber 1c for communicating the inflow passage 1a and the outflow passage 1b. As shown in FIG. 6 (A), the leak flow passage 10 is formed by a groove formed on the lower surface of the valve seat collar 2, and as shown in FIG. 6 (B), the inflow passage 1a and the outflow passage 1b. Is communicated in a non-linear manner in consideration of leakage flow rate and workability.

  Moreover, you may form the leak flow path 10 by the hole which penetrates the valve seat collar 2, for example, as shown in FIG.

  Further, as shown in FIG. 7, in the diaphragm valve having a configuration in which the valve seat collar 2 and the seat ring 4 are eliminated and the valve seat 3 is directly held by the valve box 1 to prevent the valve seat 3 from falling off, It is difficult to form the leak flow passage 10.

  Therefore, the leak flow passage 10 is configured as, for example, a through hole provided in a wall surface that separates the inflow passage 1a and the outflow passage 1b (see, for example, Patent Documents 3 and 4). Such a through-hole type leak flow passage 10 may be, for example, a through-hole provided in a wall surface that separates the inflow passage 1a from the valve chamber 1c.

  By the way, in the diaphragm valve configured as described above, when the leak flow passage 10 is configured by a groove or a through hole formed in the valve seat collar 2, for example, when applied to a diaphragm valve for high pressure fluid, Due to the high pressure fluid in the closed state, a gap is easily generated between the valve box 1 constituting the bottom wall of the valve chamber 1c and the valve seat collar 2, and the fluid flows into the outflow passage 1b from this gap. There was a problem that the minute flow rate at the time of closing deviated from the design flow rate. In addition, since the outflow amount varies depending on the finished state such as the surface roughness between the valve box 1 and the valve seat collar 2 due to the occurrence of this gap, the opening cross-sectional area and path of the leak flow passage 10 in consideration of the leakage It is difficult to make it long.

  In addition, when the leak flow passage 10 is formed by directly forming a through hole in the valve box 1, in order to flow an appropriate minute flow rate when the valve is closed, the diameter (open sectional area) of the leak flow passage 10 is set. Although it is preferable to make it 0.5 mm or less, it is difficult to form a through-hole of such a small diameter in the deep part of the valve box 1, and the problem that workability is bad has arisen.

  Further, when the leak passage 10 is formed by directly forming a through hole in the valve box 1, it is necessary to change the minute flow rate at the time of closing after assembly of the diaphragm valve, or when the valve is closed at the time of repair or the like. When it is desired to change the minute flow rate, the valve box 1 itself has to be replaced, so that there has been a problem that the parts cost and the replacement work cost are significantly increased.

  In order to solve the above problems, the present invention provides a diaphragm valve that can suppress the outflow of fluid from other than the leak flow passage when the valve is closed, and can easily change the minute flow rate when the valve is closed. The purpose is to do.

  In order to achieve the object, the diaphragm valve according to claim 1 forms an inflow path and an outflow path and a valve box in which a valve chamber is formed in the middle of the path, and opens in a bottom wall of the valve chamber. A thick cylindrical valve seat reinforcing member that surrounds the outlet edge of the inflow passage, a resin valve seat that is fitted and held so that a part protrudes from the valve seat reinforcing member, and a protruding portion of the valve seat A diaphragm valve comprising: a diaphragm that closes / opens by approaching / separating from the valve; and a pressing member that presses at least the valve seat reinforcing member toward the bottom wall of the valve chamber. Are formed with a leak flow passage penetrating from the inner peripheral wall surface to the outer peripheral wall surface so as to communicate the inflow passage and the outflow passage, and an annular rib protruding from the contact surface with the bottom wall of the valve chamber. It is characterized by.

  Thereby, the diaphragm valve can suppress the outflow of fluid from other than the leak flow passage due to the presence of the annular rib, and can easily change the minute flow rate when the valve is closed.

  The diaphragm valve according to claim 2 is characterized in that the valve seat reinforcing member is made of a material having higher mechanical strength and elasticity than the valve seat.

  As a result, the valve seat reinforcing member can be configured using a material having higher mechanical strength than the resin that is the constituent material of the valve seat, so even when a high-power drive device is used for high-pressure fluid. It is possible to avoid deformation of the leak flow passage provided in the valve seat reinforcement member and change of the opening area, and not only can easily stabilize the fluid outflow amount from the leak flow passage but also when the valve is closed. It is possible to precisely set the minute flow rate of the design flow rate.

  Furthermore, the diaphragm valve according to claim 3 is characterized in that a plurality of the annular ribs have a multiple rib structure provided in the inner and outer peripheral directions.

  Thereby, the sealing performance between the bottom wall of the valve chamber and the valve seat reinforcing member can be further improved.

  Moreover, the diaphragm valve according to claim 4 is characterized in that the annular rib is formed corresponding to a pressing direction of a pressing portion that is formed on the pressing member and presses the valve seat reinforcing member. .

  Thereby, the pressing force to the annular rib can be made efficient, and the adhesion with the bottom wall of the valve chamber can be further ensured.

  According to the diaphragm valve of the present invention, it is possible to suppress the outflow of fluid from other than the leak flow passage when the valve is closed, and it is possible to easily change the minute flow rate when the valve is closed.

  Next, an embodiment according to the diaphragm valve of the present invention will be described with reference to the drawings.

  FIG. 1 is a cross-sectional view of a diaphragm valve according to an embodiment of the present invention, and FIG. 2 is an enlarged cross-sectional view of a main part of the diaphragm valve according to an embodiment of the present invention.

  1 and 2, a diaphragm valve according to an embodiment of the present invention includes an inflow passage 11a and an outflow passage 11b, and a valve box 11 having a valve chamber 11c formed in the middle of the passage, and a valve chamber 11c. A valve seat collar 12 as a thick-walled cylindrical valve seat reinforcement member surrounding the edge of the inflow channel outlet opening in the bottom wall of the resin, and made of resin that is fitted and held so that a part protrudes from the valve seat collar 12 As a pressing member that presses at least the valve seat collar 12 toward the bottom wall of the valve chamber 11c, the diaphragm 15 that closes and opens when the valve seat 13 approaches and separates from the protruding portion of the valve seat 13. And a seat ring 14, a leak flow passage 20 penetrating from the inner peripheral wall surface to the outer peripheral wall surface so that the inflow passage 11 a and the outflow passage 11 b communicate with the valve seat collar 12, and the bottom wall of the valve chamber 11 c An annular ring protruding from the contact surface And 12a, are formed.

  Thereby, the outflow of fluid from other than the leak flow passage 20 can be suppressed when the valve is closed, and the minute flow rate can be easily changed when the valve is closed.

  Specifically, the diaphragm valve of the present invention includes an inflow passage 11a and an outflow passage 11b, and a valve box 11 having a valve chamber 11c formed in the middle of the passage, and an inflow opening in the bottom wall of the valve chamber 11c. A cylindrical valve seat collar 12 that surrounds the outlet edge of the passage 11a, a valve seat 13 that is fitted and held in the valve seat collar 12 and has a height higher than the valve seat collar 12, and an outer peripheral step portion of the valve seat 13 A seat ring 14 in which a plurality of flow holes 14a that are engaged in the circumferential direction and communicated with the outflow passage 11b are formed at equal intervals, a diaphragm 15 that is pressed and adhered to the valve seat 13, and an outer peripheral edge on the upper surface side of the diaphragm 15 A diaphragm presser 16 that presses the outer peripheral edge of the lower surface thereof toward the upper surface near the outer periphery of the seat ring 14, a bonnet 17 that closes the upper space of the valve chamber 11c and fastens and fixes the diaphragm presser 16; A pressing piece 18 which presses close contact with the central portion of the diaphragm 15 to the valve seat 13 by driving through to driver 19 a central portion of N'netto 17, a.

  The valve box 11 includes a substantially cylindrical main body 11d, tubular body portions 11e and 11f that project from the outer wall surface of the main body 11d to form an inflow passage 11a and an outflow passage 11b, and an outer peripheral wall that surrounds the bottom wall of the valve chamber 11c. 11g are integrally formed. The material and size of the valve box 11 or the opening cross-sectional areas of the inflow passage 11a and the outflow passage 11b are adapted to the original function of the valve to be applied, the fluid type, the fluid temperature, and the like.

  The valve seat collar 12 is made of a thick, substantially cylindrical body made of metal or a resin material (for example, polyimide or polybenzimidazole) having higher mechanical strength than the valve seat 13, and the peripheral wall of the valve chamber 11c is formed by the peripheral wall thereof. The outlet edge of the inflow passage 11a that opens to the bottom wall is surrounded. In addition, a valve seat 13 is embedded in the valve seat collar 12 so that a part of the valve seat collar 12 protrudes from the upper surface of the drawing so as to be in contact with the diaphragm 15. Further, the valve seat collar 12 is integrally formed with an annular rib 12a having a gasket structure protruding from the lower surface thereof toward the bottom wall of the valve chamber 11c. Further, the valve seat collar 12 is formed with a leak flow passage 20 penetrating from the inner peripheral wall surface to the outer peripheral wall surface. In addition, by providing a plurality of annular ribs 12a such as an inner peripheral side and an outer peripheral side to form a multi-rib structure, the sealing performance to the bottom wall of the valve chamber 11c can be further improved. The material and thickness of the valve seat collar 12, the protruding amount and the number of the ribs 12a, the opening cross-sectional area of the leak passage 20 and the path length (for example, a V-shaped path shape) and the like are applied. A valve according to the original function, fluid type, fluid temperature, etc. is applied.

  In the present embodiment, the valve seat 13 is made of a synthetic resin such as ethylene trifluorochloride resin (PCTFE). Further, the valve seat 13 is made of a material that is inferior in mechanical strength and elastic to the valve seat collar 12 and has an adhesiveness due to deformation when the diaphragm 15 comes into contact, that is, the valve closed state is maintained. It is secured. In addition, the material, thickness, height (projection amount from the valve seat collar 12), etc. of the valve seat 13 are applied according to the original function of the valve to be applied, fluid type, fluid temperature, and the like. .

  The seat ring 14 is made of stainless steel. Further, the seat ring 14 is formed with an annular tongue portion 14b that presses the valve seat collar 12 and the valve seat 13 together. Note that the leak flow passage 20 is formed below the lower end of the seat ring 14 and is blocked by the seat ring 14 even if compression deformation occurs when the diaphragm 15 is in a closed state where the diaphragm 15 is in contact with the valve seat 13. It is formed in a position where it cannot be. At this time, the amount of displacement of the presser piece 18 is set so that the compression deformation of the valve seat collar 12 does not change the opening cross-sectional area of the leak flow passage 20.

  The diaphragm 15 is composed of a laminate of nickel alloy or the like, and is formed in a substantially dome shape so as to bulge toward the center of the distal end of the restraining piece 18 when in the valve open state. The diaphragm 15 has rigidity (easiness of deformation), durability (corrosiveness, etc.) depending on its material and thickness, depending on the original function of the applied valve, fluid type, fluid temperature, etc. Is done.

  The diaphragm presser 16 has a substantially cylindrical shape with an annular flange projecting outwardly, and the presser piece 18 passes through coaxially with the central opening. The diaphragm presser 16 is thicker toward the outer periphery of the lower end, thereby supporting the upper surface of the outer periphery of the diaphragm 15 near the outer periphery of the lower end.

  For example, the bonnet 17 fixes (supports) the drive unit 19 and is screwed to the inner wall side of the outer peripheral wall 11 g of the valve box 11. At this time, the bonnet 17 presses the diaphragm retainer 16 against the bottom wall side of the valve chamber 11 c, whereby the diaphragm retainer 16 presses the seat ring 14 against the bottom wall of the valve chamber 11 c via the diaphragm 15.

  A cylindrical body is used for the presser piece 18, and it moves forward and backward (extends and contracts) along the axial direction in response to the drive of the drive unit 19 by being linked or connected to the drive unit 19, and its retracted position (shrinkage) The valve opening can be adjusted by a stroke from the position (top dead center) to the advanced position (extension position / bottom dead center).

  The drive unit 19 moves the holding piece 18 forward and backward along the axial direction by using, for example, a linear motion mechanism such as a solenoid, a piston, an actuator, or a manual operation dial. ) And when the diaphragm 15 and the valve seat 13 are separated from each other, the valve is opened. When the diaphragm 15 and the valve seat 13 are in close contact at the bottom dead center (state shown in FIG. 2), the valve is closed. To do. The mechanism of the drive unit 19 is not particularly limited.

  In the above configuration, the outer peripheral surface of the diaphragm 15 is sandwiched between the outer peripheral lower surface of the diaphragm retainer 16 and the outer peripheral upper surface of the seat ring 14, so that the vicinity of the central portion of the lower surface of the diaphragm 15 contacts the valve seat 13. It functions as a valve body that opens and closes and opens and closes the passage between the inflow path 11a and the outflow path 11b.

  Opening and closing by the diaphragm 15 is performed by adjusting the relative position of the valve seat 13 with respect to the diaphragm 15 by moving the pressing piece 18 up and down by driving the drive unit 19.

  Here, since the leak flow passage 20 is formed in the valve seat collar 12, even if the valve 15 is closed by the diaphragm 15 shown in FIG. A small amount of the flow path between the flow path 11b and the outflow path 11b is opened, and fluid flow from the inflow path 11a to the outflow path 11b can be ensured.

  At this time, between the bottom wall of the valve chamber 11 c and the valve seat collar 12, due to the presence of the annular rib 12 a formed in the valve seat collar 12, the tightening pressure contact force from the diaphragm retainer 16 is passed through the seat ring 14 via the seat ring 14. By transmitting to the seat collar 12a, the annular rib 12a is pressed against the bottom wall of the valve chamber 11c, and the generation of a gap can be suppressed. As shown in FIG. 3, if the annular rib 12a is formed so as to correspond directly below the annular tongue portion 14b, it can receive the pressure from the annular rib 12a efficiently. Adhesion can be further ensured.

  Further, by changing the opening cross-sectional area, the path length, and the like of the leak flow passage 20, the flow rate of the fluid can be finely adjusted.

  At this time, in order to change the opening cross-sectional area, path length, etc. of the leak flow passage 20, simply replace the valve seat collar 12 itself with the one in which the leak flow path 20 having the desired opening cross-sectional area, path length, etc. is formed. good.

  Thus, in the diaphragm valve of the present invention, the inflow path 11a and the outflow path 11b are formed, and the valve box 11 in which the valve chamber 11c is formed in the middle of the path, and the bottom wall of the valve chamber 11c is opened. A valve seat collar 12 as a thick cylindrical valve seat reinforcement member surrounding the inlet passage outlet edge, and a resin valve seat 13 fitted and held so as to partially protrude from the valve seat collar 12 A diaphragm 15 that closes and opens by approaching and separating from the protruding portion of the valve seat 13, and a seat ring 14 as a pressing member that presses at least the valve seat collar 12 toward the bottom wall of the valve chamber 11c, And the valve seat collar 12 protrudes from the contact surface between the leak flow passage 20 penetrating from the inner peripheral wall surface to the outer peripheral wall surface and the bottom wall of the valve chamber 11c so as to communicate the inflow passage 11a and the outflow passage 11b. An annular rib 12a that forms Is by that, it is possible to suppress the outflow of fluid from the non-leak passage 20 when the valve is closed, yet it is possible to easily change the minute flow rate at the time of closing.

  At this time, by configuring the valve seat collar 12 using a material having higher mechanical strength than the resin that is the constituent material of the valve seat 13, the valve can be used even when a high-power drive device is used for high-pressure fluid. The leak flow passage 20 provided in the seat collar 12 can be prevented from being deformed to change the opening area, and the amount of fluid outflow from the leak flow passage 20 can be easily stabilized. The minute flow rate at the time can be set precisely with respect to the design flow rate.

  Further, the annular rib 12a provided in the valve seat collar 12 causes the pressing force transmitted during assembly from the diaphragm retainer 16 to act on the annular rib 12a via the seat ring 14 as a pressing member. Generation | occurrence | production of the clearance gap between a wall and the valve seat collar 12 can be suppressed.

  Furthermore, since the leak flow passage 20 can be formed by forming a through hole from the outer peripheral wall surface of the valve seat collar 12 toward the inner peripheral wall surface, compared with the case where the leak flow passage 10 is directly provided in the valve box 1. In addition, the minute flow rate when the valve is closed after the valve assembly or during repair can be easily changed by replacing the valve seat collar 12.

It is sectional drawing of the diaphragm valve which concerns on one Embodiment of this invention. It is an expanded sectional view of the important section of the diaphragm valve concerning one embodiment of the present invention. It is an expanded sectional view of the important section of the modification of the diaphragm valve concerning one embodiment of the present invention. It is explanatory drawing of an example of the gas piping system in a semiconductor or liquid crystal manufacturing line. It is sectional drawing of the diaphragm valve of the prior art example 1. FIG. The diaphragm valve of the prior art example 1 is shown, (A) is a bottom view of the valve seat collar, and (B) is an explanatory view of the relationship between the inflow path and the outflow path in the leak flow path. It is sectional drawing of the diaphragm valve of the prior art example 2. FIG. It is sectional drawing of the diaphragm valve of the prior art example 3. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Valve box 11a ... Inflow path 11b ... Outflow path 11c ... Valve chamber 12 ... Valve seat collar (valve seat reinforcement member)
13 ... Valve seat 14 ... Seat ring (pressing member)
14a ... Distribution hole 15 ... Diaphragm 16 ... Diaphragm presser 17 ... Bonnet 18 ... Presser piece 19 ... Drive part 20 ... Leak flow passage

Claims (4)

A valve box in which an inflow path and an outflow path are formed and a valve chamber is formed in the middle of the path, and a thick cylindrical valve seat reinforcing member surrounding an inflow path outlet edge opening in the bottom wall of the valve chamber A resin-made valve seat that is fitted and held so that a part thereof protrudes from the valve seat reinforcing member, and a diaphragm that closes and opens by approaching and separating from the protruding portion of the valve seat, In a diaphragm valve comprising: a pressing member that presses the valve seat reinforcing member toward the bottom wall of the valve chamber;
The valve seat reinforcing member includes an annular rib projecting from a contact surface between a leak flow passage penetrating from an inner peripheral wall surface to an outer peripheral wall surface so as to communicate the inflow passage and the outflow passage, and a bottom wall of the valve chamber. And a diaphragm valve.   The diaphragm valve according to claim 1, wherein the valve seat reinforcing member is made of a material having higher mechanical strength and elasticity than the valve seat.   The diaphragm valve according to claim 1 or 2, wherein a plurality of the annular ribs are multi-rib rib structures provided in an inner and outer peripheral direction.   The said annular rib is formed in the said press member, and is formed corresponding to the press direction of the press part which presses the said valve seat reinforcement member, The Claim 1 thru | or 3 characterized by the above-mentioned. Diaphragm valve.

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