JP2010266012A - Resin diaphragm type fluid control valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin diaphragm type fluid control valve where the fatigue deterioration of the variable diaphragm of a diaphragm valve element hardly proceeds accompanied by the opening/closing of the valve and the distortion of the variable diaphragm is not caused by fluid pressure during opening the valve to allow a continuously use of the diaphragm valve element over a long period of time with high durability while reducing a pressure loss during opening the valve. <P>SOLUTION: In the resin diaphragm type fluid control valve, a central portion 3a of the synthetic resin diaphragm valve element 3 is held at the front end of a valve operating shaft 2 and a peripheral portion 3b of the diaphragm valve element 3 is clamped at the side of a valve case 1 so that the central portion 3a of the diaphragm valve element 3 leaves from and contacts with a valve seat 11 by the drive of the valve operating shaft 2 to be moved forward and backward to close and open the valve. At the back side of the diaphragm valve element 3, a presser ring 4 is arranged for holding the peripheral portion 3b of the diaphragm valve element 3 between an annular step 13 at the inner periphery side of the valve case 1 and itself. Thereby, a back supporting part 40 is constituted where the inner periphery of the presser ring 4 closely contacts with and leaves from the back of the variable diaphragm 30 of the diaphragm valve element 3 during the opening/closing of the valve. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a resin diaphragm type fluid control valve that includes a diaphragm valve body made of a synthetic resin and that controls the opening and closing of a flow path by interposing various liquid transport pipes in the food industry, the pharmaceutical industry, and the like.

  In general, a diaphragm type fluid control valve has a central portion of a diaphragm valve body held at a tip portion of a valve operating shaft disposed opposite to a valve seat in a valve chamber, and a peripheral portion of the diaphragm valve body is on a valve case side. The central part of the diaphragm valve body is separated from the annular valve seat to open and close the flow path by driving the valve operating shaft forward and backward (Patent Documents 1 and 2).

  Conventionally, rubber diaphragms have been widely used as such diaphragm valves. However, in the food industry, pharmaceutical industry, etc., it has been disliked that the odor peculiar to rubber is transferred to liquids handled in recent years. A material made of a synthetic resin having high corrosion resistance such as the above is often used.

JP 2007-224984 A JP 2008-190546 A

  However, the diaphragm valve body made of synthetic resin has significantly inferior deformation resistance and less elasticity and stretchability than those made of rubber, and in the conventional valve configuration, the variable valve portion of the diaphragm valve body accompanying the opening and closing of the valve is used. Since the amount of deformation becomes large, fatigue deterioration of the variable membrane portion progresses rapidly due to repetition of the on-off valve, and the variable membrane portion easily receives distortion due to a large fluid pressure when the valve is opened. There is a problem that the running cost is increased due to the replacement of the valve body, and there is a problem that much labor and time are spent for the replacement work, and the pressure loss due to deformation of the variable membrane portion when the valve is opened structurally increases. There was also a difficulty.

  In view of the above-described circumstances, the present invention is a resin diaphragm type fluid control valve, in which fatigue deterioration of the variable membrane portion of the diaphragm valve body accompanying opening and closing of the valve does not easily proceed, and the variable membrane portion of the variable membrane portion due to fluid pressure at the time of valve opening An object of the present invention is to provide a diaphragm valve element which is not distorted and has a high durability and can be used continuously for a long period of time, and also has a reduced pressure loss when the valve is opened.

  If the means for achieving the above object is shown with reference numerals in the drawings, the invention of claim 1 is a diaphragm valve body made of synthetic resin at the tip of the valve operating shaft 2 disposed opposite to the valve seat 11. 3 is held, and the peripheral portion 3b of the diaphragm valve body 3 is sandwiched between the valve case 1 and the valve operating shaft 2 is driven forward and backward so that the central portion 3a of the diaphragm valve body 3 is moved to the valve seat. In the resin diaphragm type fluid control valve that opens and closes the flow path (12A, 12B) by being separated from and connected to the diaphragm 11, a diaphragm is formed between the rear surface side of the diaphragm valve body 3 and the annular step portion 13 on the inner peripheral side of the valve case 1. A presser ring 4 that clamps the peripheral portion of the valve body 3 is provided, and the inner peripheral side of the presser ring 4 is in close contact with the back surface side of the variable membrane portion 30 of the diaphragm valve body 3 when the valve is opened, and the valve is closed. Back surface receiving part 4 that is sometimes separated from the variable film part 30 It is assumed that was formed by configuring the.

  According to a second aspect of the present invention, in the resin diaphragm type fluid control valve according to the first aspect, a disc spring 5 for biasing the presser ring 4 in a pressing direction with respect to the diaphragm valve body 3 is disposed on the back side of the presser ring 4. It is set as the structure which becomes.

  According to a third aspect of the present invention, in the resin diaphragm type fluid control valve according to the first or second aspect, the annular concave step portion 41 facing the annular step portion 13 on the inner peripheral side of the valve case 1 is provided on the peripheral portion 4b of the presser ring 4. The annular convex part 31 fitted to the annular concave step part 41 of the presser ring 4 is formed in the peripheral part on the back side of the diaphragm valve body 3 while being formed.

  According to a fourth aspect of the present invention, in the resin diaphragm type fluid control valve according to any of the first to third aspects, the valve chamber 10 has a radial cross section when the variable membrane portion 30 of the diaphragm valve body 3 is opened and closed. The surface of the back receiving part 40 of the presser ring 4 forms a convex curved surface 40a.

  A fifth aspect of the present invention is the resin diaphragm type fluid control valve according to any one of the first to fourth aspects, wherein the valve seat 11 is an annular valve seat formed at the periphery of the fluid inlet 12a opened in the valve chamber 10. It is configured.

  The invention of claim 6 is the resin diaphragm type fluid control valve according to any one of claims 1 to 5, wherein a bottomed cylindrical portion 31 is formed on the back side of the central portion 3a of the diaphragm valve body 3, and this bottomed The insert 6 is screwed inside the cylindrical portion 31, and the bottomed cylindrical portion 31 to which the insert 6 is screwed is inserted into the cup-shaped retainer 7 with the center hole 70, while the valve operation is performed. The tip of the shaft 2 is formed in a cylindrical shape having an annular step 2a on the inner periphery, and a mounting bolt 8 is loaded in the tip of the valve operating shaft 2 so as to lock the head 8a to the annular step 2a. Then, the male threaded portion 8b of the mounting bolt 8 projecting from the tip of the valve operating shaft 2 is screwed and fastened to the insert 6 through the center hole 70 of the cup-like retainer 7, whereby the diaphragm valve body 3 is fixed to the tip of the valve operating shaft 2. It is set as the structure fixed to the part.

  Next, effects of the present invention will be described with reference numerals in the drawings. First, in the resin diaphragm type fluid control valve according to the first aspect of the present invention, the presser ring 4 that clamps the peripheral portion 3b of the synthetic resin diaphragm valve body 3 with the annular step portion 13 on the inner peripheral side of the valve case 1. The back receiving portion 40 provided on the inner peripheral side of the presser ring 4 is in close contact with the back side of the variable membrane portion 30 of the diaphragm valve body 3 when the valve is opened, and further toward the back side of the variable membrane portion 30 In addition, the back receiving portion 40 of the presser ring 4 is separated from the variable membrane portion 30 when the valve is closed, so that the amount of deformation of the variable membrane portion 30 accompanying opening and closing of the valve is reduced. As a result, the fatigue deterioration of the diaphragm valve body 3 is unlikely to proceed, and the fluid pressure at the time of opening the valve is received by the presser ring 4, so that the deformation of the variable film portion 30 does not occur. Therefore, although the diaphragm valve body 3 is made of a synthetic resin, the diaphragm valve body 3 exhibits excellent durability and can be used continuously over a long period of time. The running cost can be reduced as much, and the operating efficiency is also increased due to a decrease in replacement frequency. Further, since the deformation of the variable membrane portion 30 of the diaphragm valve body 3 at the time of valve opening is suppressed as described above, the pressure loss due to the deformation is also reduced, and the energy efficiency is improved.

  According to the second aspect of the present invention, since the presser ring 4 is urged in the pressing direction with respect to the diaphragm valve body 3 by the disc spring 5 on the back side, the pressure impact when the valve is opened is absorbed by the disc spring 5. At the same time, the reaction force against the fluid pressure is evenly applied to the entire peripheral portion 3b from the variable membrane portion 30 of the diaphragm valve body 3 through the presser ring 4, so that local fatigue of the diaphragm valve body 3 is avoided. Further, even if the fluid has pulsation, the variable membrane portion 30 of the diaphragm valve body 3 can be reasonably following and deformed by the buffering action of the disc spring 5, so that the fatigue deterioration of the diaphragm valve body 3 is reduced.

  According to the third aspect of the present invention, the annular concave step portion 41 is formed in the peripheral portion 4b of the presser ring 4 so as to oppose the annular step portion 13 on the inner peripheral side of the valve case 1, and the diaphragm valve body is formed in the annular concave step portion 41. Since the annular convex part 31 provided on the back side of the peripheral part 3b of 3 is fitted, a tensile force to the center side acts on the diaphragm valve body 3 with opening and closing of the valve, or the resin material is made of fluorine resin or the like Even if a thermal contraction force is applied in some cases, the peripheral portion 3b of the diaphragm valve body 3 does not move inward, so that leakage due to the internal movement of the peripheral portion 3b is reliably prevented.

  According to the invention of claim 4, the variable membrane portion 30 of the diaphragm valve body 3 is curved convexly toward the flow passage space 10 a side of the valve chamber 10 in the radial cross section when the valve is closed, and the back receiving portion 40 of the presser ring 4. Since the surface of the diaphragm valve 40a has a convex curved surface 40a, the deformation of the variable membrane portion 30 of the diaphragm valve body 3 due to the opening and closing of the valve is only the expansion and contraction of the degree of curvature, and therefore the fatigue deterioration of the diaphragm valve body 3 is more difficult to proceed. Durability is further improved.

  According to the invention of claim 5, since the valve seat 11 is an annular valve seat formed at the periphery of the fluid inlet 12a opened in the valve chamber 10, a direct pressure impact at the time of valve opening causes the diaphragm valve body 3 to open. In addition to the central portion 3a, the pressure impact on the variable membrane portion 30 is small and is applied evenly in the circumferential direction, so that the durability of the diaphragm valve body 3 is further improved.

  According to the invention of claim 6, the insert 6 is screwed into the bottomed cylindrical part 32 on the back side of the diaphragm valve body 3, and the bottomed cylindrical part 32 is inserted into the inside of the cup-shaped retainer 7. The diaphragm valve body 3 is fixed to the distal end portion of the valve operating shaft 2 by screwing and tightening the mounting bolt 8 projecting from the cylindrical distal end portion of the valve operating shaft 2 to the insert 6. By simply attaching and detaching the mounting bolt 8, the diaphragm valve body 3 can be easily attached and detached, and the diaphragm valve body 3 made of synthetic resin can be securely held via the insert 6, and the diaphragm valve body 3 is attracted by the mounting bolt 8. In addition, the resin of the bottomed cylindrical portion 32 can be compressed and a strong and stable mounting state can be realized.

It is a longitudinal cross-sectional view of the resin diaphragm type fluid control valve which concerns on one Embodiment of this invention, Comprising: A valve opening state is shown in the left half part, and a valve closing state is shown in the right half part. It is a longitudinal cross-sectional view of the principal part in the valve opening state of the resin diaphragm type fluid control valve. It is a schematic plan view which shows the flow-path structural example to which the resin diaphragm type fluid control valve of this invention is applied, (a) is a connection part of a single flow path, (b) is from 1 flow path to another 1 flow path. A branch connection part, (c) shows a branch connection part from one flow path to the other two flow paths, and (d) shows a branch part from one flow path to the three flow paths.

  The resin diaphragm type fluid control valve shown in FIG. 1 has an air cylinder as a valve drive unit at the upper part of a valve case 1 having an inlet side channel 12A and an outlet side channel 12B and a valve chamber 10 communicating with them. 20 is attached, and a cylindrical valve operating shaft 2 integrally formed at the lower portion of the piston 21 in the air cylinder 20 is plunged into a central position in the valve chamber 10 so as to freely advance and retract. A circular diaphragm valve element 3 is attached to the lower end portion of the central portion 3a via a cup-shaped retainer 7 and a mounting bolt 8. And, at the bottom of the valve chamber 10, the fluid inlet 12a of the inlet-side channel 12A is opened in a circular shape at the central position, and the outlet 12b of the outlet-side channel 12B is opened in a circle on the side. A peripheral edge portion of the fluid inlet 12a constitutes an annular valve seat 11 that opens and closes when the central portion 3a of the diaphragm valve body 3 is separated.

  The diaphragm valve body 3 is made of a synthetic resin molded product such as a fluororesin, and as shown in FIG. 2, a thin variable film between the thick disc-shaped central portion 3a and the thick annular peripheral portion 3b. A bottomed cylindrical portion 32 is formed on the back side of the central portion 3a, and the ezate 6 that is a metal cylindrical body having a thread groove formed on the inner and outer peripheral surfaces is provided with the bottomed cylindrical portion 32. It is screwed inside.

  The central portion 3a of the diaphragm valve body 3 is fitted inside a cup-shaped retainer 7 having a bottomed tubular portion 32 into which the entate 6 is screwed and opened downward, and a cylindrical shaft portion 7a at the upper end of the retainer 7 is fitted to the center portion 3a. In a state of being inserted into the lower end opening of the valve operating shaft 2, the male threaded portion 8 b of the mounting bolt 8 loaded into the valve operating shaft 2 from above is screwed and tightened into the enether 6 through the center hole 70 of the retainer 7. Thus, the valve operating shaft 2 is attached to the lower end portion. The mounting bolt 8 locks the head portion 8 a to the annular step portion 13 provided on the inner periphery of the lower end portion of the valve operating shaft 2 via a flat washer 81 and a spring washer 82.

  The peripheral portion 3b of the diaphragm valve body 3 includes an upward annular step portion 13 formed on the inner periphery of the valve case 1 and a metal presser ring 4 disposed on the back side (upper side) of the diaphragm valve body 3. It is hold | maintained at the valve case 1 side by being pinched between the outer peripheral parts 4a. Therefore, the inside of the valve chamber 10 is isolated by the diaphragm valve body 3 into a lower flow space 10a and an upper ventilation space 10b. The valve case 1 is provided with an air hole 14 that communicates the upper ventilation space 10b with the outside.

  Accordingly, the inner peripheral side of the presser ring 4 is a back surface receiving portion 40 having a convex curved surface 40a on the lower surface side, and the diaphragm valve body 3 is variable when the valve is opened as shown by the right half of FIG. 1 and the solid line of FIG. It is in close contact with the back side of the membrane portion 30 and is configured to be separated from the variable membrane portion 30 when the valve is closed, as indicated by the left half of FIG. 1 and the phantom line of FIG. Further, as shown in FIGS. 1 and 2, an annular concave step 41 is formed on the lower surface side of the outer peripheral portion 4 a of the presser ring 4, and the annular concave step 41 has a peripheral portion 3 b of the diaphragm valve body 3. An annular convex portion 31 provided on the back side is fitted.

  Further, in the ventilation space 10 b of the valve chamber 10, two disc springs 5 are disposed between the downward annular step portion 15 provided on the inner periphery of the valve case 1 and the presser ring 4 so that the outer peripheral edge side is in a compressed state. The presser ring 4 is urged in the direction of pressing against the diaphragm valve body 3 by the elastic force of the disc springs 5. The presser ring 4 and the disc spring 5 are set to have an inner diameter that does not contact the cup-like retainer 7 that moves up and down integrally with the valve operating shaft 2.

  A compression coil spring 22 that urges the piston 21 in the downward movement direction is loaded between the upper wall portion 20a and the piston 21 in the air cylinder 20, and the lower side is valved at the center of the cylinder. A piston shaft 23 that is screwed onto the internal thread portion 2 b on the inner periphery of the operating shaft 2 and integrated with the piston 21 is disposed. The piston shaft 21 has a cylindrical shaft shape with an internal thread 21a provided on the inner periphery of the upper end portion, the upper side penetrates the upper wall portion 20a of the air cylinder 20 so as to be movable up and down, and a bolt-shaped plug body 24 is screwed into the upper end portion. An annular stopper 23b for defining the upper limit position of the piston 21 by abutment with the upper wall portion 20a is projected on the outer periphery of the upper portion of the arrangement portion in the cylinder, and the piston 21 is provided on the outer periphery of the lower portion. A flange portion 23c that abuts on the inner bottom portion and positions the piston 21 is provided. Reference numeral 25 denotes a supply / discharge port of compressed air for operation with respect to the cylinder front chamber 26a on the lower side of the piston 21, and 27 denotes a vent hole for the cylinder rear chamber 26b on the upper side.

  A portion where the upper side of the piston shaft 21 penetrates the upper wall portion 20a of the air cylinder 20 and a portion where the valve operating shaft 2 penetrates the bottom wall portion 20b of the air cylinder 20 and the upper wall portion 1a of the valve case 1 are Each is hermetically sealed by a seal ring 9.

  In the resin diaphragm type fluid control valve having the above configuration, when the compressed air is not introduced into the cylinder front chamber 26 a of the air cylinder 20, the valve operating shaft 2 is moved downward integrally with the piston 21 by the urging of the compression coil spring 22. As shown by the right half of FIG. 1 and the solid line of FIG. 2, the center portion 3 a of the diaphragm valve body 3 is pressed against the annular valve seat 11, and the fluid L supplied to the inlet-side flow path 12 </ b> A. The flow to the outlet side flow path 12B is blocked by the blocking of the outlet 21a. In this valve-closed state, the variable membrane portion 30 of the diaphragm valve body 3 is separated from the back surface receiving portion 40 of the presser ring 4 while being convexly curved toward the flow path space 10a.

  On the other hand, when compressed air is introduced into the cylinder front chamber 26a of the air cylinder 20, the valve operating shaft 2 moves up integrally with the piston 21 against the bias of the compression coil spring 22, and the left half of FIG. 2 and the phantom line in FIG. 2, the central portion 3a of the diaphragm valve body 3 is opened from the annular valve seat 11, and the fluid L supplied to the inlet-side channel 12A flows from the outlet 21a to the channel. It flows into the outlet side channel 12B from the outlet 12b through the space 10a.

  In this valve open state, the pressure of the fluid L is applied to the variable membrane portion 30 of the diaphragm valve body 3, but the variable membrane portion 30 is in close contact with the back surface receiving portion 40 of the presser ring 4, so that the fluid pressure is at the presser ring 4. The variable film portion 30 is not received and does not act so as to extend, and deformation of the variable film portion 30 itself to the back side is also prevented. Moreover, since the surface of the back receiving portion 40 of the presser ring 4 is a convex curved surface 40a, the variable membrane portion 30 of the diaphragm valve body 3 at the time of valve opening has a slightly increased degree of curvature from the state at the time of valve closing. become.

  Therefore, although the diaphragm valve body 3 is made of a synthetic resin such as a fluororesin, which has inferior deformation resistance compared to rubber and has poor elasticity and stretchability, the variable membrane portion 30 associated with the opening and closing of the valve is used. Since the deformation is very small, it is difficult for fatigue deterioration to occur, and the fluid pressure at the time of valve opening is received by the presser ring 4 so that the deformation of the variable film portion 30 does not occur. Furthermore, since the presser ring 4 is urged in the pressing direction with respect to the diaphragm valve body 3 by the disc spring 5 on the back side, the pressure impact at the time of opening the valve is absorbed by the disc spring 5 and is counteracted against the fluid pressure. The force is evenly applied to the entire peripheral portion 3b from the variable membrane portion 30 of the diaphragm valve body 3 through the presser ring 4, so that local fatigue of the diaphragm valve body 3 is also avoided. Further, even if the fluid L has a pulsation, the variable membrane portion 30 of the diaphragm valve body 3 can be forcedly deformed by the buffering action of the disc spring 5, so that the fatigue deterioration of the diaphragm valve body 3 is further reduced.

  And in this resin diaphragm type fluid control valve, as described above, the diaphragm valve body 3 exhibits excellent durability and can be used continuously for a long period of time, so that the running cost can be reduced by that much, and the replacement frequency of the diaphragm valve body The operating efficiency is also increased by the reduction of the pressure, and the deformation of the variable membrane portion 30 of the diaphragm valve body 3 at the time of valve opening is suppressed, so that the pressure loss due to the deformation is reduced and the energy efficiency is improved. Further, since the peripheral portion 3b of the diaphragm valve body 3 is fitted to the annular concave step portion 41 of the presser ring 4 by the annular convex portion 31, a tensile force toward the center side acts on the diaphragm valve body 3 as the valve is opened and closed. If the resin material is a fluororesin or the like, the peripheral portion 3b of the diaphragm valve body 3 does not move inward even if a heat shrinking force is applied, so that leakage due to the inward movement of the peripheral portion 3b occurs. Liquid is reliably prevented.

  As the synthetic resin constituting the diaphragm valve body 3, a fluororesin is particularly suitable, but various other synthetic resins can be used as long as they have good chemical resistance. Preferred fluorine-based resins include, for example, tetrafluoroethylene resin (trade name: Teflon PTFE, fullon, etc.), copolymer resin of tetrafluoroethylene and perfluoroalkyl vinyl ether (trade name: Teflon PFA), four Terpolymer resin of fluoroethylene, perfluoroalkyl vinyl ether and propylene hexafluoride (trade name: Teflon EPE), copolymer resin of tetrafluoroethylene and hexafluoropropylene (trade name: Teflon FEP), Copolymer resin of tetrafluoroethylene and ethylene (trade name: Teflon ETFE, Tefzel) Polyvinylidene fluoride resin (trade name: Teflon PVDF, Kyner), copolymer of trifluoromonochloroethylene and ethylene (trade name: Teflon) ECTFE), monofluoroethylene resin (trade name: Teflon P F), and the like.

  The resin diaphragm type fluid control valve of the present invention can be applied to various valve seat configurations. However, as in the above-described embodiment, the valve seat 11 is formed on the peripheral edge of the fluid inlet 12a opened in the valve chamber 10. In this case, since the direct pressure impact at the time of opening the valve is applied to the central portion 3a of the diaphragm valve body 3, the pressure impact on the variable membrane portion 30 is small and is applied evenly in the circumferential direction. There is an advantage that the durability of the body 3 is further improved. Further, as in the above embodiment, the insert 6 is screwed into the bottomed cylindrical portion 32 on the back side of the diaphragm valve body 3, and the bottomed cylindrical portion 32 is inserted inside the cup-shaped retainer 7. If the structure is such that the mounting bolt 8 protruding from the cylindrical tip of the valve operating shaft 2 is screwed into and tightened to the insert 6 and the diaphragm valve body 3 is fixed to the tip of the valve operating shaft 2, the mounting bolt The diaphragm valve body 3 can be easily attached and detached by the attaching / detaching operation 8, and the diaphragm valve body 3 made of synthetic resin can be securely held via the insert 6, and by attaching the diaphragm valve body 3 with the mounting bolt 8, A strong and stable mounting state can be realized by using the resin of the bottom cylindrical portion 32 as a compressed state.

  Further, the configuration of the flow path connecting portion to which the resin diaphragm type fluid control valve of the present invention is applied is not particularly limited, but as illustrated in FIGS. A configuration in which the fluid inlet 12a forms the annular valve seat 11 and has a fluid outlet 12b connected to one or a plurality of outflow channels on the side thereof is preferable. In FIG. 3, the valve chamber 10 is indicated by a virtual line circle, and the fluid flow is indicated by an arrow. In the figure, the configuration of (a) is a single channel connecting portion corresponding to the above embodiment, and the configuration of (b) is a branch connecting portion from a fluid inlet 12a opened in the middle of one channel to another channel. (C) is a branch connection part from the fluid inlet 12a opened in the middle of one flow path to the other two flow paths, and (d) is a branch part from one flow path to the three flow paths.

  In the embodiment, the air cylinder system is adopted as the valve operating mechanism. However, in the present invention, various other valve operating mechanisms such as a hydraulic cylinder system and an electromagnetic drive system can be employed. In addition, the detailed configuration of the resin diaphragm type fluid control valve of the present invention can be variously modified in addition to the embodiment.

DESCRIPTION OF SYMBOLS 1 Valve case 10 Valve chamber 10a Flow path space 11 Annular valve seat 11
12A Inlet side flow path 12a Fluid inlet 13 Annular step part 2 Valve operating shaft 2a Annular step part 3 Diaphragm valve element 3a Central part 3b Peripheral part 30 Variable film part 31 Annular convex part 32 Bottomed cylindrical part 4 Pressing ring 4a Peripheral part 40 Back receiving part 40a Convex curved surface 41 Annular concave step part 5 Belleville spring 6 Ensert 7 Cup-shaped retainer 70 Center hole 8 Mounting bolt 8a Head 8b Male thread part

Claims (6)

The central portion of the diaphragm valve body made of synthetic resin is held at the tip of the valve operating shaft disposed opposite to the valve seat, and the peripheral portion of the diaphragm valve body is clamped on the valve case side, so that the valve operating shaft moves forward and backward. In the resin diaphragm type fluid control valve that opens and closes the flow path by driving the central portion of the diaphragm valve body away from the valve seat,
A presser ring is provided on the back side of the diaphragm valve body so as to sandwich the peripheral portion of the diaphragm valve body with the annular stepped portion on the inner peripheral side of the valve case, and the inner peripheral side of the presser ring is opened when the valve is opened. A resin diaphragm type fluid control valve which is in close contact with the back surface side of the variable membrane portion of the diaphragm valve body and constitutes a back surface receiving portion which is separated from the variable membrane portion when the valve is closed.   The resin diaphragm type fluid control valve according to claim 1, wherein a disc spring for urging the presser ring in a pressing direction with respect to the diaphragm valve body is disposed on the back side of the presser ring.   An annular concave step portion is formed in the peripheral portion of the presser ring so as to be opposed to the annular step portion on the inner peripheral side of the valve case, and is fitted to the annular concave step portion of the presser ring on the peripheral portion on the back side of the diaphragm valve body. The resin diaphragm type fluid control valve according to claim 1 or 2, wherein an annular convex portion is formed.   The variable membrane portion of the diaphragm valve body is curved convexly toward the flow passage space side of the valve chamber in a radial section when the valve is closed, and the surface of the back receiving portion of the presser ring forms a convex curved surface. The resin diaphragm type fluid control valve according to any one of the above.   The resin diaphragm type fluid control valve according to any one of claims 1 to 3, wherein the valve seat is an annular valve seat formed at a peripheral edge of a fluid inlet opening in the valve chamber.   A bottomed cylindrical portion is formed on the back side of the central portion of the diaphragm valve body, and an entrant is screwed to the inside of the bottomed cylindrical portion, and the bottomed cylindrical portion to which the enzaat is screwed is the center. The tip of the valve operating shaft is formed in a cylindrical shape having an annular step on the inner periphery, and the mounting bolt is installed in the tip of the valve operating shaft. Is fixed to the annular stepped portion, and the male screw portion of the mounting bolt protruding from the tip of the valve operating shaft is screwed and tightened to the enether through the center hole of the cup-shaped retainer, thereby to obtain a diaphragm valve. The resin diaphragm type fluid control valve according to any one of claims 1 to 5, wherein a body is fixed to a tip portion of the valve operating shaft.

Images