JP6292553B2 - Diaphragm valve - Google Patents

Description

  The present invention relates to a diaphragm valve used in, for example, a high-pressure gas cylinder, a high-pressure gas piping facility, and the like, and more particularly, to a diaphragm valve that secures the airtightness of a closed valve chamber by sandwiching the diaphragm between two members.

  Conventionally, there are a pack type valve and a diaphragm type valve as valves used in high pressure gas cylinders, high pressure gas piping facilities, and the like. Pack type valves use packing type joints or bolts to ensure airtightness inside the valve, while diaphragm type valves use a thin metal plate diaphragm that bends as the valve body moves to ensure airtightness inside the valve. Is secured.

  When comparing the two valves, the pack-type valve has a long life because it does not use a consumable diaphragm, and can be used repeatedly by being disassembled and maintained. On the other hand, in the diaphragm type valve, the diaphragm is deteriorated. For this reason, the diaphragm type valve has a shorter life than the pack type valve. However, the diaphragm type valve can be disposed of within a range that does not exceed a predetermined service life and number of times of use, thereby ensuring safety without maintenance. . In recent years, disposable diaphragm valves are becoming an international de facto standard because of such ease of handling. Examples of conventional diaphragm valves include the following.

  In FIG. 1 of Japanese Patent Laid-Open No. 63-72984 (Patent Document 1), a disk 4 for opening and closing the inflow passage 10 is provided, and a boss 14 inserted through a small diameter portion of the disk 4 is attached to the diaphragm 3. A diaphragm type valve having a structure in which the periphery of the through hole is welded has been proposed.

  1 to 3 of Japanese Patent Application Laid-Open No. 08-219304 (Patent Document 2) includes a disk 7 for opening and closing a gas passage 1a, and an inner peripheral edge of the diaphragm 2 on a shaft portion 7b of the disk 7. A diaphragm type valve having a structure in which the parts are welded has been proposed.

  In FIG. 1 and FIG. 2 of Japanese Patent Application Laid-Open No. 08-114265 (Patent Document 3), the inner peripheral edge of the diaphragm 11 is sandwiched between annular flat portions 6 a and 8 a formed in the weld metal 8 and the sheet holder 6. A diaphragm type valve having a configuration in which the diaphragm 11, the weld metal fitting 8, and the seat holder 6 are welded (W) and fixed and integrated is proposed.

  FIG. 1 and FIG. 2 of Japanese Patent Application Laid-Open No. 2004-257549 (Patent Document 4) show a diaphragm type valve in which a plurality of diaphragms 61 and 62 are welded to a cylindrical fitting portion 43 of a valve body 41. Has been proposed.

JP 63-72984 A Japanese Patent Laid-Open No. 08-219304 Japanese Patent Laid-Open No. 08-114265 JP 2004-257549 A JP-A-63-140190 Special table 2001-509579 gazette

<Welding problems>
In the conventional diaphragm type valve, the airtightness of the closing valve chamber is ensured by welding the periphery of the through hole of the diaphragm to the seating stem. However, when the diaphragm is welded, deformation (welding distortion) occurs from the welded portion. When the diaphragm in which the welding distortion occurs is operated, the periphery of the welded portion is easily damaged by fatigue. In addition, the beam welding of the diaphragm requires much labor and cost, and the beam welding exceeds at least 10% of the manufacturing cost of the diaphragm type valve.

  FIG. 3 of Japanese Patent Laid-Open No. 63-1410190 (Patent Document 5) describes a configuration in which the annular pressing portion 36 provided in the member main body 30 is clamped and fixed to the metal diaphragm 34. . FIG. 1 of JP-T-2001-509579 (Patent Document 6) has a configuration in which a doughnut-shaped sealing bead 72 provided on the valve function member 64 is sealingly engaged with the concave inner surface 30 of the diaphragm 26. Have been described.

  However, in the annular pressing portion 36 of Patent Document 5, the contact portion with the metal diaphragm 34 is a flat surface. Further, the sealing bead 72 of Patent Document 6 has a rounded surface in contact with the diaphragm 26. Such flat surface or rounded surface contact cannot withstand the internal pressure of the closing valve chamber when high-pressure gas flows. For this reason, in the diaphragm type valve for high pressure gas, the actual product to which the annular pressing part 36 or the sealing bead 72 is applied did not exist before the patent application of the present application.

<Flow problem>
In the conventional diaphragm type valve, the flow rate of gas per unit time is determined by the operation amount of the diaphragm. Usually, the operation amount of the diaphragm is as extremely small as about 0.5 mm. Generally, the diaphragm type valve has a small gas flow rate per unit time. As a means for increasing the gas flow rate, it is conceivable to increase the operation amount of the diaphragm. However, when the operation amount of the diaphragm is increased, the periphery of the above-described welded portion is more quickly fatigued.

  Here, it is also conceivable to apply the annular pressing portion 36 of Patent Document 5 and the sealing bead 72 of Patent Document 6 so that the diaphragm is not welded. However, if the diaphragm is operated greatly, the flat surface of the annular pressing portion 36 or the round surface of the sealing bead 72 cannot be maintained, and high-pressure gas leaks from the closing valve chamber.

<Life issues>
Conventional diaphragm valves have been premised on single use. For example, in a diaphragm type valve that targets a corrosive liquefied gas such as ammonia, hydrogen chloride, or chlorine, a valve body (disk) and a diaphragm that come into contact with the corrosive gas are likely to deteriorate. For this reason, the conventional diaphragm valve has been discarded when either the valve element or the diaphragm reaches the end of its life.

  However, the main components such as the valve body, spindle, gland nut and spindle receiver of the conventional diaphragm type valve are all made of metal having corrosion resistance. Discarding the main components that can still be used sufficiently even if some parts such as the valve body or the diaphragm deteriorate is contrary to the recent social demand for emphasis on recycling.

  Further, in the conventional diaphragm type valve, the diaphragm is integrally welded to the valve body or a metal part holding the same. In view of this, it is conceivable that a part in which the valve body and the diaphragm are integrated can be replaced, and the main components are reused. However, if the valve body deteriorates first, the diaphragm that has not reached the end of its life must be discarded together. Conversely, if the diaphragm deteriorates first, the valve element that has not yet reached the end of its life must be discarded. In particular, it is unreasonable to dispose of a diaphragm that is costly for beam welding before reaching its end of life.

<Problems with coil springs>
Some conventional diaphragm type valves have a built-in coil spring that generates an urging force in the opening direction of the valve body (for example, the spring 81 shown in FIG. 1 of Patent Document 4). However, the coil spring is difficult to keep parallel in the vertical direction, and an uneven load tends to be generated in its urging force. Such an unbalanced load causes contact of the valve body and causes gas leakage.

  Further, in the conventional diaphragm type valve, a space for accommodating the coil spring vertically in the valve main body must be secured, and the entire valve is enlarged in the height direction.

  The present invention has been made in view of the above problems, and can ensure the airtightness of the closing valve chamber without welding the diaphragm, can increase the flow rate of gas per unit time, An object of the present invention is to provide a diaphragm type valve that can prolong the service life and reuse the main components by replacing parts, and can effectively prevent the uneven load on the valve body.

(1) In order to achieve the above object, a diaphragm type valve of the present invention is a diaphragm type valve used for the circulation of high pressure gas, and is a hollow valve provided with an inflow path and an outflow path for the high pressure gas. A main body, a diaphragm forming a closing valve chamber for connecting the inflow passage and the outflow passage for the high-pressure gas in the valve main body, and a first portion for sandwiching a central portion of the diaphragm from the inside and outside of the closing valve chamber A second holding member; and a valve body that opens and closes the inflow passage of the high-pressure gas in conjunction with the first and second holding members, and the first holding member located in the closing valve chamber includes the The contact portion is formed of a series of edges that surround the central axis of the diaphragm.

(2) Preferably, in the diaphragm type valve of the above (1), a series of bulging portions are formed in the diaphragm so as to surround the central portion thereof and bulge toward the outside of the closing valve chamber.

(3) Preferably, in the diaphragm valve according to (1) or (2), the diaphragm includes a plurality of diaphragms stacked on one another, and one diaphragm that contacts the first holding member among the plurality of diaphragms. However, it is good to make it the structure formed with the material of lower hardness than other tire frames.

(4) Preferably, in the diaphragm valve according to any one of (1) to (3), an O-ring surrounding the central axis of the diaphragm is attached to the inner side of the contact portion of the first holding member. It is good to have a configuration.

(5) Preferably, in the diaphragm type valve according to any one of the above (1) to (4), one or more that generates an urging force in the opening direction of the valve body with respect to the first and second holding members. It is good to make it the structure provided with this disk spring.

  According to the diaphragm type valve of the present invention, the airtightness of the closed valve chamber can be ensured without welding the diaphragm, the gas flow rate per unit time can be increased, the life of the diaphragm is increased, and the parts are replaced. The main component parts can be reused by the above, and the uneven load on the valve body can be effectively prevented.

It is sectional drawing which shows the diaphragm type valve which concerns on embodiment of this invention. It is an enlarged view which shows the principal part of the said diaphragm type valve in the open state of a seat disk (valve body). It is an enlarged view which shows the principal part of the said diaphragm type valve in the closed state of a seat disk. It is a perspective view which shows the diaphragm of this embodiment. The seating stem (1st holding member) of this embodiment is shown, The figure (a) is the perspective view seen from upper direction, The figure (b) is the perspective view seen from the downward direction. FIG. 3 is a partially enlarged view of FIG. 2. It is a perspective view which shows the diaphragm fixing nut (2nd holding member) of this embodiment.

  Hereinafter, a diaphragm type valve according to an embodiment of the present invention will be described with reference to the drawings. In the following description, the JIS code is omitted when illustrating the type of stainless steel or the like.

<Configuration of diaphragm type valve>
In FIG. 1, a diaphragm valve 1 according to this embodiment mainly includes a valve body 10, a spindle 20, a handle 30, a ground nut 40, a spindle receiver 50, a diaphragm 60, a seating stem (first holding). Member) 70, a diaphragm fixing nut (second holding member) 80, a ground washer 90, a disc spring 100, and a seat disk (valve element) 110.

<< Valve body >>
As shown in FIG. 1, the valve body 10 is a housing in which a hollow portion 11 a having a circular cross section is provided in the body portion 11. The valve body 10 is formed of a metal material having corrosion resistance, for example, SUS316L stainless steel. The body portion 11 is provided with male screw portions 12 and 13 branched downward and laterally. In the lower male threaded portion 12, a gas inflow path 14 that leads to the hollow portion 11 a is provided. Further, a gas outflow passage 15 communicating with the inside of the hollow 11a is provided in the side male screw portion 13.

  An inflow path 14 and an outflow path 15 open at the lower end side of the hollow portion 11a. By closing the lower end side of the hollow portion 11a with a disk-shaped diaphragm 60, the closing valve chamber 16 is formed. As shown in FIG. 2, a gas inlet 14 a is opened in the closing valve chamber 16. The inflow port 14 a is opened and closed by the seat disk 110.

<< Spindle and handle >>
In FIG. 1, the spindle 20 is a shaft member for opening and closing the seat disk 110. The spindle 20 is made of, for example, stainless steel such as SUS304 having corrosion resistance. Here, in the present embodiment, when specifying the part of the spindle 20, the lowermost part of the spindle 20 shown in FIG.

  In order from the top of FIG. 1, a male screw for attaching the handle 30 is provided at the rear end portion 21 of the spindle 20. The handle 30 is fixed to the rear end portion 21 of the spindle 20 by fastening the nut 23 to the male screw. The handle 30 is made of an aluminum alloy such as ADC12, for example.

  The front end portion 22 of the spindle 20 has a larger diameter than the rear end portion 21. A male screw is provided on the outer periphery of the large-diameter tip 22. This male screw is screwed into the female screw of the ground nut 40. Accordingly, when the handle 30 is rotated, the spindle 20 linearly moves in the vertical direction in the drawing (that is, the opening / closing direction of the seat disk 110) at the pitch of the screw.

  An end surface of the tip portion 22 of the spindle 20 is a convex curved surface 22a. As shown in FIG. 2, the convex curved surface 22 a of the tip portion 22 of the spindle 20 abuts on a flat seat 51 assembled to the spindle receiver 50. The rotational motion and linear motion of the spindle 20 are transmitted to the spindle receiver 50 through slight surface contact between the convex curved surface 22 a of the tip portion 22 and the flat seat 51.

<< Ground nut >>
In FIG. 1, the gland nut 40 is screwed into a female screw provided on the inner wall surface of the hollow portion 11 a of the valve body 10. The ground nut 40 seals the hollow portion 11a of the valve body 10 and supports the spindle 20 rotatably. As shown in FIG. 2, when the gland nut 40 is screwed into the valve body 10, the gland washer 90 is pressed by the annular lower end surface 40a.

  The ground nut 40 is made of, for example, stainless steel such as SUS303 or SUS304, or brass (brass) such as C3604BD that has been plated with nickel to give corrosion resistance. In particular, brass (brass) such as C3604BD that has been nickel-plated to provide corrosion resistance is preferable.

<< Spindle support >>
In FIG. 2, the spindle receiver 50 has a flat seat 51 and a male screw portion 52. The flat seat 51 receives the convex curved surface 22 a of the tip portion 22 of the spindle 20. The abutment surface of the flat seat 51 is a flat surface, and makes slight surface contact with the convex curved surface 22 a of the tip portion 22 of the spindle 20. The spindle receiver 50 is made of, for example, stainless steel such as SUS304 having corrosion resistance. Further, the flat seat 51 is formed, for example, by quenching and hardening carbon tooling steel such as JIS SK5 having higher hardness than the spindle receiver 50. By making the flat seat 51 high in hardness, it is possible to prevent wear, deformation, and seizure of the spindle receiver 50 due to contact with the convex curved surface 22a of the tip portion 22 of the spindle 20.

<< Diaphragm >>
In FIG. 2, the diaphragm 60 seals the closing valve chamber 16 of the valve body 10 while allowing the seat disk 110 to open and close. As shown in FIGS. 2 and 3, the diaphragm 60 can be deformed in a direction perpendicular to the radial direction thereof. As the operation amount (deformation amount) of the diaphragm 60 increases, the distance between the seat disk 110 and the inlet 14a increases, and the gas flow rate per unit time increases.

  Here, as shown in FIG. 4, the diaphragm 60 of the present embodiment is configured by superposing two diaphragms 60 </ b> A and 60 </ b> B. Both of these diaphragms 60A and 60B have the same shape and size. A through hole 61 is provided at the center of the diaphragms 60A and 60B. A male screw portion 73 (see FIG. 2) of the seating stem 70 is inserted into the through hole 61.

  A series of bulging portions 62 surrounding the through hole 61 are formed in the diaphragms 60A and 60B. As shown in FIG. 2, the bulging portion 62 swells in an arc shape toward the outside of the closing valve chamber 16. Moreover, as shown in FIG. 4, the whole bulging part 62 continues in an annular shape. Such a bulging portion 62 is provided in order to increase the operation amount of the diaphragms 60A and 60B. As shown in FIG. 3, when the spindle 20 is moved in the closing direction of the seat disk 110 (downward in the figure, the direction of the white arrow), the bulging portion 62 bends and deforms in a direction perpendicular to the radial direction, and the diaphragm The central portions of 60A and 60B operate greatly.

  2 and 4, the region between the through hole 61 and the bulging portion 62 of the two diaphragms 60 </ b> A and 60 </ b> B is sandwiched between the diaphragm fixing nut 80 and the seating stem 70. The lower diaphragm 60B faces the inside of the closing valve chamber 16 and contacts the edge 71a of the seating stem 70 (see FIGS. 5A and 6). In order to improve the sealing performance due to this contact, the lower diaphragm 60B is formed of a material that is relatively soft and excellent in corrosion resistance. The lower diaphragm 60B is formed of a metal material subjected to an annealing process such as SUS316L stainless steel, O material, or BA material.

  On the other hand, the upper diaphragm 60 </ b> A faces the outside of the closing valve chamber 16 and comes into contact with the protrusion 82 (see FIG. 7) of the diaphragm fixing nut 80. The upper diaphragm 60A reinforces the lower diaphragm 60B formed of a soft material. The upper diaphragm 60 </ b> A is formed of a relatively hard material that can withstand the high pressure of the closing valve chamber 16. The upper diaphragm 60A is formed of, for example, SUS304H.

<< Seating Stem >>
In FIG. 2, the seating stem 70 sandwiches the diaphragms 60 </ b> A and 60 </ b> B and is tightened with a diaphragm fixing nut 80. The seating stem 70 is formed of a material having a mechanical strength capable of withstanding a strong tightening torque of the diaphragm fixing nut 80 and having corrosion resistance, for example, stainless steel such as SUS630. A fitting recess 72 is formed on the bottom surface of the seating stem 70. The seat disk 110 is caulked and fixed in the fitting recess 72. On the other hand, a male screw portion 73 is provided at the center of the top surface of the seating stem 70. The male screw portion 73 is inserted into the through hole 61 of the diaphragm 60 and screwed into the female screw of the diaphragm fixing nut 80. The sheeting stem 70 sandwiches a region between the through hole 61 and the bulging portion 62 of the diaphragm 60 together with the diaphragm fixing nut 80.

  Here, as shown in FIGS. 5A and 6, a circular groove 74 surrounding the male screw portion 73 is formed in the center portion of the upper surface 71 of the seating stem 70. An O-ring 75 is inserted into the groove 74. The O-ring 75 is made of, for example, nitrile rubber. As shown in FIG. 6, the upper surface 71 of the seating stem 70 is an inclined surface that descends from the center toward the outside. Such a circular inner peripheral edge of the upper surface 71 forms a series of edges 71 a at the highest position on the upper surface 71. The edge 71a becomes a contact portion with the lower diaphragm 60B.

<< Diaphragm fixing nut >>
In FIG. 2, the diaphragm fixing nut 80 is formed of stainless steel such as SUS304, for example. The diaphragm fixing nut 80 includes a nut body 81 having a hexagonal column and a projecting portion 82 formed integrally therewith. A ground washer 90 and a disc spring 100 are attached to the outside of the nut body 81. The ground washer 90 attached to the nut body 81 is locked to the upper surface of the protruding portion 82.

  An internal thread is formed on the inner wall surface of the nut body 81. The male screw portion 52 of the spindle receiver 50 is screwed onto the upper side of the female screw. A male screw portion 73 of the seating stem 70 is screwed into the lower side of the female screw via the diaphragm 60. Accordingly, the spindle receiver 50, the diaphragm fixing nut 80, the diaphragm 60, and the seating stem 70 are connected to each other. The spindle receiver 50, the diaphragm fixing nut 80, and the seating stem 70 move in the opening / closing direction of the seat disk 110 as the spindle 20 moves linearly.

  Here, as shown in FIG. 7, the protrusion 82 of the diaphragm fixing nut 80 is formed with a flat surface 82a and a tapered surface 82b. The flat surface 82a contacts the region between the through hole 61 and the bulging portion 62 of the upper diaphragm 60A. The tapered surface 82b is provided so as to surround the flat surface 82a.

<< Grand Washer >>
In FIG. 2, the ground washer 90 is formed of stainless steel such as SUS304. The ground washer 90 is a thick disk-shaped member and has substantially the same diameter as the diaphragm 60. Such a ground washer 90 is hermetically fixed in the hollow portion 11 a of the valve body 10 via an O-ring 91. The ground washer 90 is pressed by the annular lower end surface 40 a of the ground nut 40.

  The ground washer 90 has an annular pressing surface 90 a that abuts on the outer peripheral portion 63 (see FIG. 4) of the diaphragm 60. The outer peripheral portion 63 of the diaphragm 60 is sandwiched between the pressing surface 90 a of the ground washer 90 and the circular protrusion 17 provided on the valve body 10. Thereby, the airtightness in the outer peripheral part 63 of the diaphragm 60 is ensured.

<< Belleville spring >>
In FIG. 2, the disc spring 100 is formed of stainless steel such as SUS304, for example. In the present embodiment, five disc springs 100 are alternately stacked with their front and back reversed. The five disc springs 100 generate an urging force in the upward direction in the drawing (the opening direction of the sheet disk 110) between the spindle receiver 50 and the ground washer 90.

<< Sheet Disc >>
2 and 5B, the seat disk 110 controls the gas flow by opening and closing the gas inlet 14a of the valve body 10. The sheet disk 110 is formed of a resin material that is excellent in air tightness and does not easily deform even when used for many years. The sheet disc 110 is made of, for example, PCTFE, PVDF, polyamide, or the like. As a material of the sheet disk 110, PCTFE is particularly suitable.

<Effects of diaphragm type valve>
Next, various functions and effects achieved by the diaphragm valve 1 described above will be described with reference to the drawings.

<< Ensuring airtightness by edge >>
As shown in FIG. 6, in the diaphragm type valve 1 of the present embodiment, the region between the through hole 61 and the bulging portion 62 of the diaphragm 60 is the flat surface 82 a of the diaphragm fixing nut 80 and the edge of the seating stem 70. 71a. With this configuration, the edge 71a is engaged with the lower diaphragm 60B, and the airtightness of the closing valve chamber 16 is ensured.

  In particular, in the diaphragm valve 1 of the present embodiment, the lower diaphragm 60B is formed of a material that is softer than the edge 71a. With this configuration, the airtightness between the lower diaphragm 60B and the edge 71a is significantly improved.

  Further, the strength of the lower diaphragm 60B formed of a soft material is supplemented by the upper diaphragm 60A formed of a harder material. That is, by combining the soft diaphragm 60B and the hard tire diaphragm 60A, it becomes possible to obtain sufficient strength to withstand the high pressure of the closing valve chamber 16 while ensuring the airtightness of the closing valve chamber 16 by the edge 71a. .

  Further, an O-ring 75 is inserted further inside the edge 71a. With this configuration, even when the airtightness between the lower diaphragm 60B and the edge 71a is lowered due to long-term use, the O-ring 75 continues to support ensuring airtightness.

  As described above, according to the diaphragm valve 1 of the present embodiment, conventional beam welding is unnecessary, and fatigue failure around the through hole 61 is reduced. As a result, the life of the diaphragm valve 1 is extended. Further, the labor and cost for beam welding are reduced, and the manufacturing cost of the diaphragm valve 1 is reduced.

<< Increase of gas flow >>
As shown in FIG. 4, the diaphragm valve 1 of the present embodiment has a configuration in which a series of bulging portions 62 surrounding the through hole 61 are formed in the diaphragms 60 </ b> A and 60 </ b> B. With this configuration, the diaphragm 60 can be greatly deformed in a direction orthogonal to the radial direction. Further, the diaphragm valve 1 of the present embodiment is configured to greatly move the seating stem 70 in the opening direction of the seat disk 110 using the biasing force of the disc spring 100. As a result, as shown in FIGS. 2 and 3, the operation amount of the diaphragm 60 is increased, and the gas flow rate per unit time is increased.

  In the conventional diaphragm type valve, the operation amount of the diaphragm is about 0.5 mm. On the other hand, the diaphragm type valve 1 of this embodiment can make the operation amount of the diaphragm 60 1.0 mm. Furthermore, since the diaphragm valve 1 according to the present embodiment does not weld the diaphragm 60 to the seating stem 70, even if the diaphragm 60 is operated greatly, fatigue failure is not accelerated. In particular, the edge 71a bites into the lower diaphragm 60B, and the airtightness of the closing valve chamber 16 is ensured. Thereby, even if the diaphragm 60 is operated largely, the contact between the edge 71a and the lower diaphragm 60B is maintained, and the airtightness of the closing valve chamber 16 is ensured.

  In addition, as shown in FIG. 7, the diaphragm valve 1 of the present embodiment has a configuration in which a tapered surface 82 b surrounding the flat surface 82 a is formed in the diaphragm fixing nut 80. As shown in FIGS. 2 and 3, the tapered surface 82 b avoids contact with the bulging portion 62 of the upper diaphragm 60 </ b> A, and allows deformation of the diaphragm 60 in a direction perpendicular to the radial direction. With such a tapered surface 82b, the diaphragm 60 can always be deformed greatly without difficulty.

<< Longer life of diaphragm type valve >>
In the diaphragm type valve 1 of the present embodiment, the diaphragm 60 is not welded to the seating stem 70, so the life of the diaphragm 60 is extended. Further, the diaphragm valve 1 of the present embodiment is configured such that the diaphragm 60 is held between the edges 71 a of the seating stem 70. With this configuration, the diaphragm valve 1 of the present embodiment can replace only the diaphragm 60 that has reached the end of its life. Therefore, in the diaphragm type valve 1 of the present embodiment, the main components such as the valve main body 10, the spindle 20, the ground nut 40, and the spindle receiver 50 are replaced by individually replacing the seat disk 110 or the diaphragm 60 that has reached the end of its life. Can be reused.

<< Prevention of uneven load >>
As shown in FIGS. 2 and 3, the diaphragm valve 1 of the present embodiment generates a biasing force in the opening direction of the seat disk 110 by the disc spring 100. The disc spring 100 is easy to keep the parallel in the vertical direction compared to the coil spring used in the conventional diaphragm type valve, and the biasing force is less likely to be generated. The urging force of the disc spring 100 with very little unbalanced load can effectively prevent the seat disk 110 from hitting one side and prevent gas leakage.

<< Miniaturization of diaphragm type valve >>
Compared to a coil spring of a conventional diaphragm valve (for example, the spring 81 shown in FIG. 1 of Patent Document 4), the disc spring 100 of the diaphragm valve 1 of the present embodiment is compact in the height direction. However, a sufficient biasing force can be generated. Therefore, the space for accommodating the disc spring 100 in the valve main body 10 is reduced, and the diaphragm type valve 1 as a whole can be downsized in the height direction.

DESCRIPTION OF SYMBOLS 1 Diaphragm type valve 10 Valve body 11 Body 11a Hollow part 12, 13 Male thread part 14 Inflow path 14a Inlet 15 Outlet 15a Outlet 16 Closing valve chamber 17 Protruding part 20 Spindle 21 Rear end part 22 End part 22a Convex curved surface 23 Nut 30 Handle 40 Ground nut 40a Lower end surface 50 Spindle receiver 51 Flat seat 60, 60A, 60B Diaphragm 61 Through hole 62 Swelling portion 63 Outer peripheral portion 70 Seating stem (first holding member)
71 Upper surface 71a Edge 72 Fitting recess 73 Male thread portion 74 Groove 75 O-ring 80 Diaphragm fixing nut (second holding member)
81 Nut body 82 Projecting portion 82a Flat surface 82b Tapered surface 90 Ground washer 90a Pressing surface 91 O-ring 100 Belleville spring 110 Seat disc (valve element)

Claims (4)

A diaphragm type valve used for the circulation of high-pressure gas,
A hollow valve body provided with an inflow path and an outflow path for the high-pressure gas;
In the valve body, a diaphragm that forms a closed valve chamber that connects the inflow path and the outflow path of the high-pressure gas;
A first and a second holding member for sandwiching the central portion of the diaphragm from the inside and outside of the closing valve chamber;
A valve body for opening and closing the high-pressure gas inflow passage in conjunction with the first and second holding members;
With
The first holding member located in the closing valve chamber is provided with a contact portion composed of a series of edges surrounding the central axis of the diaphragm ,
A diaphragm type valve characterized in that a series of bulging portions are formed in the diaphragm so as to surround a central portion thereof and bulge toward the outside of the closing valve chamber . Comprising a plurality of said diaphragms being stacked together, among the plurality of the diaphragms, one diaphragm in contact with the first holding member, than other tire Fulham formed in the low hardness material, according to claim 1 Diaphragm type valve described in 1. The diaphragm type valve according to claim 1 or 2 , wherein an O-ring surrounding the central axis of the diaphragm is attached inside the contact portion of the first holding member. The diaphragm type valve according to any one of claims 1 to 3 , further comprising one or a plurality of disc springs that generate an urging force in an opening direction of the valve body with respect to the first and second holding members. .