JP4651358B2 - Diaphragm valve - Google Patents

Description

  The present invention relates to a diaphragm valve used in various industries such as a chemical factory, semiconductor manufacturing field, liquid crystal manufacturing field, food field, and more specifically, when foreign matter is mixed in the fluid flowing into the valve. However, the present invention relates to a diaphragm valve that reliably seals fluid and has excellent durability against repeated opening and closing.

  Conventional diaphragm valves include a diaphragm valve using a fluororesin diaphragm and a diaphragm valve using a rubber diaphragm as an elastic body.

  However, in the case of a fluororesin diaphragm, when solid foreign matter is mixed in the fluid flowing into the valve due to plastic deformation, if the foreign matter is caught in the seal portion, the sealing performance is deteriorated, and the foreign matter is sealed by the foreign matter. However, there is a problem that the sealing performance after the foreign matter is removed remains deteriorated. In addition, in the case of a rubber diaphragm, if solid foreign matter is mixed in the fluid flowing into the valve, even if the foreign matter is caught in the seal part, the sealing performance can be maintained by the elastic force of the rubber, Although the sealing performance after the foreign matter comes off does not deteriorate, there is a problem that it cannot be used for a long time because it may be repeatedly damaged by opening and closing.

  In order to solve these problems, there is a diaphragm valve having a structure in which the valve seat 101 as shown in FIG. 8 is difficult to be detached from the diaphragm 102 (see, for example, Patent Document 1). This diaphragm valve has a valve seat 104 formed on the valve main body 103 and a diaphragm 102 to which a valve seat 101 that contacts and separates from the valve seat 104 is attached. The valve seat 101 has a ring-shaped concave groove 105 formed on the mounting surface with the diaphragm 102. The inner wall on the outer peripheral side of the concave groove 105 is formed with an outer peripheral convex engaging portion 106 that protrudes toward the inner side of the groove. The inner wall on the inner peripheral side of the concave groove 105 has an inner peripheral convex shape that protrudes toward the inner side of the groove. An engaging portion 107 is formed. By inserting the ring-shaped projection 108 at the lower end of the diaphragm 102 into the ring-shaped concave groove 105 of the valve seat 101, the inner and outer peripheral projections are projected into the concave groove 109 and the concave groove 110 provided on the inner and outer peripheral walls of the ring-shaped projection 108. The strip engaging portions 106 and 107 are fitted. The diaphragm 102 is made of a material made of polytetrafluoroethylene (hereinafter referred to as PTFE) by machining, and the valve seat 101 is made of fluororubber which is a kind of synthetic rubber. With such a configuration, even if a force for peeling the valve seat 101 from the diaphragm 102 is applied to the valve seat 101, the valve seat 101 is difficult to be detached from the diaphragm 102.

  In addition, there is a diaphragm valve with good sealing performance even when a foreign object as shown in FIG. 9 is caught (see, for example, Patent Document 2). In this diaphragm valve, a rubber member 112 made of rubber or rubber-like plastic is filled in a recess 111 at the center of one side end face, and a plastic valve main body 113 whose end face is configured as a seal portion; A diaphragm portion 114 formed integrally with the valve body 113 is provided on the outer peripheral side. The valve body 113 is made of PTFE, polychlorotrifluoroethylene (hereinafter referred to as PCTFE) or the like, and ethylene propylene rubber (hereinafter referred to as EPDM) or the like is used as the rubber member. In this diaphragm valve, even if foreign matter is caught, the valve seat leakage does not occur, the deterioration of the sealing performance of the diaphragm valve and the valve seat is prevented, and good sealing performance is maintained over a long period of time. Can do.

JP 2001-330161 A JP 2001-349450 A

  However, in the prior art described above, the diaphragm valve having a structure in which the valve seat is not easily detached from the diaphragm is formed by inserting the ring-shaped protrusion 108 at the lower end of the diaphragm 102 into the ring-shaped concave groove 105 of the valve seat 101. 101 and the diaphragm 102 are connected, and the inner and outer peripheral ridge engaging portions 106 are inserted into the concave grooves 109 and 110 provided on the inner and outer peripheral walls of the ring-shaped protrusion 108 so that the valve seat 101 is not detached from the diaphragm 102. 107 is fitted, so that the diaphragm 102 is not detached, but when exposed to a negative pressure with the diaphragm valve open, the valve seat 101 is pulled downward and deformed, There is still a possibility of detachment from the diaphragm 102, and the material of the valve seat 101 is particularly long-term. There when degraded, leaving from the diaphragm 102 of valve seat 101 is feared.

  Further, among the conventional techniques described above, a diaphragm valve having good sealing performance even when foreign matter is bitten has a rubber member 112 made of rubber or rubber-like plastic in a recess 111 at the center of one end face of the valve body 113. Since the rubber member 112 is filled and cannot be removed from the valve body 113, the valve body 113 and the rubber member 112 cannot be disassembled when replacing parts of the diaphragm valve, and only the rubber member 112 having the highest possibility of replacement is used. There is a problem that cannot be exchanged. Further, since the valve main body 113 and the rubber member 112 cannot be disassembled, there is a problem that it is difficult to separate the materials when discarding the diaphragm valve.

  The present invention has been made in view of the above-described problems of the prior art, and even when foreign matter is mixed in the fluid flowing into the valve, the fluid is surely sealed and has excellent durability against repeated opening and closing. An object of the present invention is to provide a diaphragm valve that can be disassembled and exchanged for each individual part without the seal member being deformed and detached by fluid pressure.

The configuration of the diaphragm valve of the present invention for solving the above-described problems will be described with reference to the accompanying drawings . As in the reference example of FIG. 1, the present invention is a diaphragm valve that opens and closes a valve by pressing and separating the diaphragm 1 against the valve seat 30. The diaphragm 1 includes a diaphragm main body 2 made of a fluororesin, and a support. And a sealing member 3 made of an elastic body having a seal portion that is sandwiched and fixed to the lower surface of the diaphragm main body 2 by a body 4 and that is pressed against and separated from the valve seat portion 30 .
The seal portion of the seal member 3 is an annular ridge 12 provided on the outer edge of the seal member 3, the front Kiben seat 30, the outer peripheral portion of the formed center of a bottom surface of the valve chamber 25 a flow path Is provided on the inner peripheral edge of the valve seat portion 30 and the seal portion of the seal member 3 is received in an annular groove 57 formed by the outer peripheral surface of the support 4 and the step portion 51 when the valve is closed. Ru is.

Further, the second feature is that the outer diameter of the seal member 3 in a state where the valve is not closed is slightly smaller than the inner diameter of the stepped portion 51 of the valve seat portion 30.

A third feature is that a concave portion 65 is provided at the center of the lower surface of the diaphragm body 2 and the upper surface of the seal member 3 is fitted and fixed to the concave portion 65.

A fourth feature is that it has a fixed body 5 made of the same material as the support body 4, and the seal member 3 and the diaphragm main body 2 are sandwiched and fixed between the support body 4 and the fixed body 5. To do.

Further, a fifth feature is that annular protrusions 66 and 67 are provided on the contact surface of the diaphragm body 2 and / or the support body 4 with the seal member 3.

Further, protrusions 14 and 15 are provided on the upper surface and / or lower surface of the seal member 3, and the protrusions 14 and 15 are fitted in the concave grooves 9 and 19 provided in the diaphragm body 2 and / or the support body 4. It is the sixth feature that they are combined.

Further, a seventh feature is that the sealing member 3 includes a reinforcing cloth.

  In the present invention, referring to FIG. 4, the valve seat portion 50 may have a configuration in which a step portion 51 is provided on the inner peripheral edge portion of the valve seat portion 50. In this case, when the valve is closed, that is, when the seal member 55 and the valve seat 50 are pressed against each other, the seal member 55 is pressed against the bottom surface 58 of the stepped portion 51 and at the same time deformed so as to be crushed to the outer peripheral side by elastic force. The seal member 55 is pressed into contact with the inner peripheral surface 59 of the stepped portion 51, whereby the seal member 55 can be double-sealed at two locations of the stepped portion bottom surface 58 and the stepped portion inner peripheral surface 59, and the sealing performance increases as the fluid pressure increases. It is preferable because reliable sealing is performed and fluid does not leak.

Further, referring to FIG. 5, in order to perform the double seal more reliably, the inner diameter d ₁ of the communication port 52 and the outer diameter D ₁ of the support 53 are D ₁ = 0.920 d. _It is preferable to set within the range of _{1 to} 0.990d ₁ . In order for the flange portion 54 of the support 53 to be inserted into the communication port 52 when the valve is closed, D ₁ needs to be 0.990 d ₁ or less. Further, an annular groove 57 is formed by the outer surface of the flange 54 of the support 53 and the step portion 51, and the seal portion is deformed to the outer peripheral side when the valve is closed, so that the sealing performance of the inner peripheral surface of the step portion 51 is improved. ₁ needs to be 0.920d ₁ or more.

In addition, in order to perform the double sealing more reliably, the outer diameter D ₂ of the seal member 55 in a state where the valve is not closed is slightly smaller than the inner diameter d ₂ of the step portion 51 of the valve seat portion 50. It is preferable that the configuration has a small diameter. At this time, it is preferable to set the inner diameter d ₂ of the stepped portion 51 and the outer diameter D ₂ of the seal member 55 within a range of D ₂ = 0.985 d _{2 to} 0.999 d ₂ . In order for the seal member 55 to be deformed so as to be crushed to the outer peripheral side by the elastic force when the valve is closed and to seal with the inner peripheral surface 59 of the stepped portion 51, D ₂ needs to be 0.985d ₂ or more. In order to prevent the seal member 55 from rubbing and wearing due to contact with the inner peripheral surface 59 of the stepped portion 51 of the valve seat portion 50, D ₂ needs to be 0.999d ₂ or less.

  In the present invention, the shape of the wetted part of the support 4 is not particularly limited as long as it does not hinder the seal member 3 from being pressed against and separated from the valve seat portion 30, and is suspended from the center of the wetted surface. A projecting taper may be provided on the flange portion 17 of the support 4 so that the flow rate of the fluid can be controlled.

  In the present invention, the fixing method of each component of the diaphragm 1 is such that the sealing member 3 is sandwiched between the diaphragm main body 2 and the support 4 and fixed, so that it is screwed, bayonet connected, screwed, pinned, and fused. There is no particular limitation such as welding, and among these, any means such as heat, vibration, and ultrasonic waves may be used for fusion and welding. Further, the fixed body 5 made of the same material as the support body 4 may be provided on the diaphragm 1. If the seal member 3 and the diaphragm main body 2 are sandwiched and fixed between the support body 4 and the fixed body 5, the fixed body 5 is fixed. The method is not particularly limited as described above. At this time, since the support body 4 and the fixed body 5 are made of the same material, if it is necessary to prevent the support body 4 and the fixed body 5 from being detached, it is surely easy to use a fixing method of fusion or welding. This is preferable. Further, when the support body 4 and the diaphragm body 2 or the fixed body 5 are clamped and fixed so as to be disassembled / assembled by screwing, bayonet connection, screwing, pinning, etc., only the diaphragm body 2 or the sealing member It is suitable because it can be exchanged by itself, such as only 3, and can be separated and processed by material when discarded. The seal member 3 is sandwiched between the support body 4 and the diaphragm main body 2, and the seal member 3 is compressed and sandwiched and fixed by the support body 4 and the diaphragm main body 2 or the fixed body 5, so that the seal member 3 is fixed to the diaphragm 1. It will not leave.

  In the present invention, the protrusions 14 and 15 are provided on the upper surface and / or the lower surface of the seal member 3, and the protrusions 14 and 15 are fitted into the concave grooves 9 and 19 provided in the diaphragm body 2 and / or the support body 4. The protrusion 14 and 15 may be fitted in the concave grooves 9 and 19 to suppress the deformation of the seal member 3 and to prevent the seal member 3 from being detached from the diaphragm 1. It is.

The present invention has the structure as described above, and the following excellent effects can be obtained.
(1) Since the sealing member is provided with an elastic body, the fluid can be reliably sealed even when foreign matter is mixed in the fluid flowing into the valve, and the diaphragm body is made of a fluororesin and has fatigue resistance. Because of its strong structure, it can be used without worrying about damage even in long-term use.
(2) Since the valve seat portion is provided with a stepped portion, the seal member can perform a double seal at two locations on the bottom surface of the stepped portion and the inner peripheral surface of the stepped portion when the valve is closed, so that the sealing performance also increases as the fluid pressure increases. High and reliable sealing is performed so that fluid does not leak.
(3) Since the upper surface of the seal member is fitted and fixed in the recess provided in the center of the lower surface of the diaphragm body, the deformation due to the elastic force of the seal member is concentrated in the direction of the valve seat portion, and the force applied to the seal member is Since it can be concentrated and applied to the seal portion without escaping to the outside, the sealing performance is improved, and a reliable seal can be performed even with a high fluid pressure.
(4) Since the seal member is sandwiched between the support and the diaphragm main body, and the seal member is compressed and sandwiched and fixed by the support and the diaphragm main body or the fixed body, the seal member is not detached from the diaphragm. Further, if the protrusion provided on the seal member is fitted in the concave groove provided on the support and / or the diaphragm main body, the seal member can be prevented from being detached from the diaphragm.
(5) By forming the diaphragm so that it can be disassembled and assembled, it is possible to replace only the diaphragm main body or only the seal member as a single unit, and to dispose of the material separately for disposal.

Hereinafter, embodiments of the present invention will be described with reference to the embodiments shown in the drawings. However, it is needless to say that the present invention is not limited to the embodiments. FIG. 1 is a longitudinal sectional view showing a reference example when the valve is closed for explaining the present invention. FIG. 2 is an enlarged view of a main part of FIG. FIG. 3 is an enlarged view of a main part when the valve of FIG. 1 is opened. Figure 4 is an enlarged longitudinal sectional view showing a valve closed in the implementation of the invention. FIG. 5 is an enlarged vertical cross-sectional view showing a main part when the valve of FIG. 4 is opened. FIG. 6 is an enlarged vertical cross-sectional view of the main part showing a valve closed state of another reference example for explaining the present invention. FIG. 7 is an enlarged vertical cross-sectional view of the main part showing the valve opened in FIG.

Hereinafter, a diaphragm valve as a reference example for explaining the present invention will be described with reference to FIGS.

  1 is a diaphragm. The diaphragm 1 is formed of a diaphragm main body 2, a seal member 3, a support body 4, and a fixed body 5. Each of the structures is as follows.

Reference numeral 2 denotes a PTFE diaphragm main body. A thick portion 6 is provided at the center of the diaphragm body 2, and a through hole 7 into which the insertion portion 16 of the support 4 described later is inserted is provided at the center of the thick portion 6. A step portion 8 is provided at the portion. By inserting the insertion portion 16 of the support body 4 to be described later into the diaphragm body 2, an annular concave groove 9 is formed by the insertion portion 16 and the stepped portion 8. In addition, a thinly formed diaphragm portion 10 is provided on the peripheral edge of the thick portion 6, and an annular fitting portion 11 having a rectangular cross section is provided on the outer periphery of the diaphragm portion 10. The annular fitting portion 11 is sandwiched and fixed between the main body 22 and the lower surface of the diaphragm retainer 43 described below while being fitted in the annular groove 24 of the later-described main body 22. The diaphragm body 2 of this reference example is made of PTFE, but repeated fatigue properties such as PCTFE, polyvinylidene fluoride (hereinafter referred to as PVDF), tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer (hereinafter referred to as PFA), etc. It is not particularly limited as long as it is made of a good fluororesin.

3 is an EPDM sealing member. An annular ridge portion 12 having a semicircular cross section is provided on the outer edge portion of the seal member 3 so as to protrude downward, and the annular ridge portion 12 serves as a seal portion that is pressed against and separated from the valve seat portion 30 described later. Further, a through hole 13 into which the insertion portion 16 of the support body 4 to be described later is inserted is provided in the central portion, and the inner groove of the through hole 13 protrudes from the upper surface and the lower surface, and the concave groove 9 of the diaphragm body 2 and the support body to be described later. Protrusions 14 and 15 that are fitted into the four concave grooves 19 are provided. The material of the seal member 3 of this reference example is made of EPDM, but is not particularly limited as long as it is an elastic rubber-like elastic body such as nitrile rubber, styrene butadiene rubber, and fluoro rubber. Further, the sealing member 3 may include a high-strength reinforcing cloth such as vinylon, nylon, or polyester. In this case, the sealing member 3 is preferable because the sealing member 3 is not easily broken.

Reference numeral 4 denotes a support made of a vinyl chloride resin (hereinafter referred to as PVC). An insertion portion 16 that is fitted into the diaphragm body 2 and the through holes 7 and 13 of the seal member 3 is provided on the support 4. A flange 17 that is inserted into the communication port 26 of the main body 22 to be described later when the valve is closed is provided at the lower portion of the support 4, and an annular groove 19 is provided on the upper surface of the flange 17. A male screw portion 18 to which the fixing body 5 to be described later is screwed is provided at an end portion of the insertion portion 16, and a female screw portion 20 is provided at the upper center. The female screw portion 20 is screwed into the male screw portion 40 of the shaft portion 41 of the piston 37 described later. The material of the support 4 in this reference example is PVC, but PVDF, polypropylene (hereinafter referred to as PP), polyphenylene, etc., as long as the diaphragm main body 2 is sandwiched between the support 5 and has sufficient strength to be fixed. There is no particular limitation such as sulfide (hereinafter referred to as PPS).

  Reference numeral 5 denotes a fixed body having an annular member made of PVC. A female screw portion 21 that is screwed into the male screw portion 18 of the support 4 is formed through the center portion of the fixed body 5. In addition, if the fixing body 5 is the same material as the support body 4, it will not specifically limit.

  Next, an assembling method of the diaphragm main body 2, the seal member 3, the support body 4, and the fixed body 5 constituting the diaphragm 1 will be described. First, the protrusion 15 on the lower surface side of the seal member 3 is fitted in the concave groove 19 of the support body 4, and then the protrusion 14 on the upper surface side is fitted in the concave groove 9 of the diaphragm main body 2, thereby supporting the support body 4. Is inserted into the through hole 13 of the seal member 3 and the through hole 7 of the diaphragm main body 2, and the fixing member 5 is screwed to the support body 4 so as to compress the seal member 3 and the diaphragm main body 2. The diaphragm body 2 and the seal member 3 are sandwiched and fixed between the support 4 and the fixed body 5.

Reference numeral 22 denotes a PVC main body. An upper portion of the main body 22 has an annular protrusion 23 joined to a lower portion of a cylinder main body 31 described later, and an annular groove 24 on the inner periphery of the annular protrusion 23. A valve chamber 25 formed with the inner peripheral wall of the annular groove 24 and the diaphragm 1 is provided on the upper surface. Communication ports 26, 27 are provided at the bottom of the valve chamber 25, the communication port 26 communicates with the fluid inlet 28, and the communication port 27 communicates with the fluid outlet 29. The opening of the communication port 26 is provided at the center of the bottom of the valve chamber 25, and the peripheral edge of the opening is a valve seat 30. In addition, although the main body 22 of this reference example is a product made from PVC, if the required physical property as the main body 22 is satisfy | filled, it will not specifically limit, such as PVDF, PP, and PFA.

  A cylinder body 31 made of PPS containing glass is fixed to the upper portion of the body 22 with bolts and nuts (not shown). Inside the cylinder body 31, each space is formed in a stepped manner from the top to the upper space 32 and the lower space 33, and further, a diaphragm pressing fitting portion 34 is provided at the lower portion. A first working fluid supply port 35 communicating with the upper space 32 and a second working fluid supply port 36 communicating with the lower space 33 are formed. Note that a spring that urges the piston 37 downward may be provided in the upper space 32 of the cylinder body 31, and in this case, it can be used as a reverse operation valve. The glass content of PPS can be set to 40%, for example.

  37 is a PPS piston containing glass, and an upper part is provided with a flange 39 having an annular groove 38 for holding an O-ring on the upper outer peripheral surface. The inner peripheral surface is slidable up and down. Below, a shaft portion 41 in which an O-ring is fitted and a male screw portion 40 to be screwed to the female screw portion 20 of the support 4 is formed at the lower end portion passes through a through hole 45 of the diaphragm retainer 43 described later. In this state, it is integrally provided by hanging from the center of the flange 39. The glass content of PPS can be set to 40%, for example.

  Reference numeral 43 denotes a PPS diaphragm retainer containing glass, and an insertion portion 44 is formed below the PPS diaphragm retainer. The upper portion of the diaphragm 1 is received in the insertion portion 44. A through hole 45 into which the shaft portion 41 of the piston is inserted is formed in the center of the upper surface of the insertion portion 44, and a taper portion 46 whose diameter decreases toward the insertion portion 44 is provided on the lower surface of the diaphragm retainer 43. An O-ring 47 is disposed on the outer periphery of the diaphragm retainer 43. An annular protrusion 48 is formed on the lower outer peripheral surface, and is inserted into the diaphragm retainer fitting portion 34 of the cylinder body 31. The glass content of PPS can be set to 40%, for example.

The material of the cylinder body 31, the piston 37, and the diaphragm retainer 43 of this reference example is made of glass-filled PPS. If the material has a physical strength that can be used without problems with the pressure of the working fluid, the glass-filled PVDF, There is no particular limitation such as PP and PVC containing glass.

In addition, the diaphragm valve of this reference example is an air-driven stop valve, but may be a hydraulic drive type, and the configuration of the valve is not particularly limited as long as the diaphragm 1 is used.

Next, the operation of the diaphragm valve according to this reference example will be described with reference to FIGS.

  In the open state (the state shown in FIG. 3), when air, which is the working fluid, is injected into the first working fluid supply port 35 from this state, the upper space 32 formed by the upper portion of the piston 37 and the inner peripheral surface of the cylinder body 31 is entered. Air is injected, the piston 37 is pushed down by the pressure of the air, the diaphragm 1 is pushed down together with the support 4 connected to the piston 37, and the annular ridge portion 12, which is the seal portion of the seal member 3, is The flow path is closed by being in pressure contact with the portion 30, and the valve is closed (the state shown in FIG. 2). At this time, since the valve is sealed only by the annular protrusion 12 of the sealing member 3 which is an elastic body, when the solid foreign matter is mixed with the fluid flowing into the valve, the foreign matter is removed from the annular protrusion. Even if it is caught between the valve seat portion 30 and the valve seat portion 30, the annular ridge portion 12 is not plastically deformed, and the sealing performance can be maintained by the elastic force. When air as working fluid is injected into the second working fluid supply port 36 from the closed state (state of FIG. 2), air is injected into the lower space 33 formed between the piston 37 and the diaphragm retainer 43, and the air Since the piston 37 is pushed up by the pressure, the diaphragm 1 is also lifted upward, the seal member 3 is separated from the valve seat 30 and is lifted upward to open the valve (the state shown in FIG. 3), and the fluid flows into the fluid flow. It flows in from the inlet 28, passes through the communication port 26, the valve chamber 25, and the communication port 27, and flows out from the fluid outlet 29. If the foreign matter that has been caught at this time is removed from the annular ridge portion 12, the annular ridge portion 12 returns to its original state by the elastic force, and the subsequent sealing performance does not change. In addition, when the valve is repeatedly opened and closed during long-term use, stress due to repeated fatigue is applied particularly to the diaphragm portion 10 of the diaphragm 1, but the diaphragm body 2 is made of a fluororesin and has a structure with high fatigue resistance. Therefore, even when used for a long time, it will not be damaged by repeated opening and closing.

  Further, when the valve is closed and fluid pressure is applied, or when the diaphragm 1 is open and exposed to negative pressure, the seal member 3 is deformed and tends to come off the diaphragm 1. Since the seal member 3 and the diaphragm main body 2 are compressed and sandwiched and fixed by the support body 4 and the fixed body 5, it is difficult to come off. Furthermore, since the protrusions 14 and 15 provided on the seal member 3 are fitted in the concave grooves of the support 4 and the diaphragm main body 2, the seal member 3 is prevented from being detached from the diaphragm 1.

  Further, since the diaphragm 1 is formed by screwing, even if the seal member 3 or the diaphragm main body 2 is damaged, it is possible to replace only a single part, and the assembly of the diaphragm 1 is easy, so that the efficiency is high. . Furthermore, since it can be decomposed | disassembled for every material, such as the rubber-made sealing member 3 and the fluororesin diaphragm main body 2, a separation process is easy when discarding.

Hereinafter, the diaphragm valve is the implementation form of the present invention will be described with reference to FIGS.

49 is a main body made of PVC. The valve seat portion 50 of the main body 49 is provided with a step portion 51 at the inner peripheral edge portion. An inner diameter d1 in the vicinity of the stepped portion 51 of the communication port 52 communicating with the valve seat portion 50 and an outer diameter D1 of the support 53 are provided such that D1 = 0.96d1, and the gap is provided in a slight state. . Further, the inner diameter d2 of the step portion 51 and the outer diameter D2 of the seal member 55 are provided so that D2 = 0.997d2, and the inner diameter d2 of the step portion 51 is slightly larger than the outer diameter D2 of the seal member 55. Is provided. Further, the height h of the stepped portion 51 and the height H of the annular protrusion 56 of the seal member 55 are set to H = 1.2h. Since the diaphragm and other configurations of the present embodiment are the same as those of the above-described reference example , description thereof is omitted.

Next, the operation of the diaphragm valve is the implementation form of the present invention will be described with reference to FIGS.

When the valve is closed from the open state (the state shown in FIG. 5), the annular ridge 56 serving as the seal portion of the seal member 55 is an annular formed by the outer peripheral surface of the flange portion 54 of the support 53 and the step portion 51. When the annular ridge 56 is received in the groove 57 and pressed against the bottom surface 58 of the stepped portion 51, the annular ridge 56 is sealed with the valve seat 50 by the elastic force and is in a closed state (state shown in FIG. 4). Become. At this time, since the support 53 is inserted into the communication port 52 with a slight gap between the inner diameter of the communication port 52 and the outer diameter of the flange 54 of the support 53, the annular ridge 56 is moved to the outer peripheral side by elastic force. It is deformed so as to be crushed and is pressed against the inner peripheral surface 59 of the stepped portion 51. As a result, the seal member 55 can perform double sealing at two locations, that is, the bottom surface 58 of the step portion 51 and the inner peripheral surface 59 of the step portion 51. In this case, the annular ridge 56 of the seal member 55 is deformed by the fluid pressure when the valve is in the closed state. 59 is pressed, and the sealing performance of the inner peripheral surface 59 is enhanced. This is because the higher the fluid pressure, the higher the sealing performance. In this embodiment, even when a high fluid pressure is applied when the valve is closed, the sealing performance is high and reliable sealing is performed. There is no fluid leakage. Further, since the outer diameter of the seal member 55 is slightly smaller than the inner diameter of the stepped portion 51, the annular protrusion 56 of the seal member 55 is crushed by elastic force when the valve is closed. Except for being deformed and pressed against the inner peripheral surface 59 of the stepped portion 51, the seal member 55 is rubbed and worn out during contact with the inner peripheral surface 59 of the stepped portion 51 during the opening / closing operation of the valve. Absent. Thereby, the diaphragm 1 is not damaged due to repeated opening and closing in long-term use, and deterioration due to wear of the seal member 55 is suppressed, so that it can be used for a long time without worrying about damage or deterioration due to opening and closing. Since other operations are the same as those of the reference example described above, description thereof is omitted.

Next, a diaphragm seal structure, which is another reference example for explaining the present invention, will be described with reference to FIGS.

Reference numeral 60 denotes a diaphragm, which is formed of a diaphragm main body 61, a seal member 62, a support body 63, and a fixed body 64. A concave portion 65 is provided at the center of the lower surface of the diaphragm main body 61, and an annular protrusion 66 is provided on the bottom surface of the concave portion 65. An annular protrusion 67 is provided on the upper surface of the support 63. The seal member 62 is sandwiched between the support 63 and the diaphragm main body 61 with the upper surface fitted in the recess 65 of the diaphragm main body 61, and compresses the seal member 62 and the diaphragm main body 16 with the support 63 and the fixed body 65. By being screwed together, it is clamped and fixed. The other configuration of this reference example is the same as that of the reference example of FIGS.

Next, the operation of the diaphragm valve according to this reference example will be described with reference to FIGS.

  When the valve is closed from the open state (the state shown in FIG. 7), the annular protrusion 68, which is the seal portion of the seal member 62, is pressed against the valve seat 69 to close the flow path and the closed state (the state shown in FIG. 8). It becomes. At this time, the annular protrusion 68 tends to be deformed by elastic force, but since the seal member 62 is fitted and fixed to the recess 65 of the diaphragm main body 61, the deformation due to elastic force is in contact with the valve seat 69. Since it concentrates in the direction, the force applied to the seal member 62 can be concentrated and applied to the seal portion without escaping to the outside, so that the sealing performance is improved, and a reliable seal can be performed even with a high fluid pressure. . Even when the diaphragm 60 is open and exposed to negative pressure, unnecessary deformation of the seal member 62 can be prevented by fitting and fixing the seal member 62 to the recess 65 of the diaphragm main body 61.

  Further, each of the sealing member 62 and the diaphragm main body 61, and the sealing member 62 and the supporting body 63 is provided by the annular protruding portion 66 provided on the lower surface of the diaphragm main body 61 and the annular protrusion 67 provided on the upper surface of the supporting body 63. Since the sealing performance between the components is improved, it is possible to prevent the fluid from leaking from the combined portion of the diaphragm 60 to the driving portion side of the diaphragm valve. Since other operations are the same as those in the first embodiment, a description thereof will be omitted.

It is a longitudinal cross-sectional view which shows the time of valve closing of the reference example for demonstrating this invention. It is a principal part enlarged view of FIG. It is a principal part enlarged view at the time of valve opening of FIG. Is an enlarged longitudinal sectional view showing a valve closed in the implementation of the invention. FIG. 5 is an enlarged vertical sectional view showing a main part when the valve is opened in FIG. It is a principal part expanded longitudinal sectional view which shows the time of valve closing of the other reference example for demonstrating this invention. FIG. 7 is an enlarged vertical sectional view showing a main part when the valve in FIG. 6 is open. It is a longitudinal cross-sectional view which shows the diaphragm valve made into the structure where the conventional valve seat is hard to remove | deviate from a diaphragm. It is a longitudinal cross-sectional view which shows the diaphragm valve with favorable sealing performance even if the conventional foreign material is bitten.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Diaphragm 2 Diaphragm main body 3 Seal member 4 Support body 5 Fixed body 6 Thick part 7 Through-hole 8 Step part 9 Concave groove 10 Diaphragm part 11 Annular fitting part 12 Annular protrusion 13 Through-hole 14 Protrusion 15 Protrusion 16 Insertion portion 17 Hook portion 18 Male screw portion 19 Recessed groove 20 Female screw portion 21 Female screw portion 22 Main body 23 Annular protrusion 24 Annular groove 25 Valve chamber 26 Communication port 27 Communication port 28 Fluid inlet 29 Fluid outlet 30 Valve seat 31 Cylinder body 32 Upper space 33 Lower space 34 Diaphragm retainer fitting portion 35 First working fluid supply port 36 Second working fluid supply port 37 Piston 38 Groove portion 39 Gutter portion 40 Male thread portion 41 Shaft portion 42 Groove portion 43 Diaphragm retainer 44 Insertion Fitting part 45 Through hole 46 Tapered part 47 O-ring 48 Annular protrusion 49 Main body 50 Valve seat part 51 Step part 52 Communication port 53 Support body 54 55 sealing member 56 annular ridge 57 annular groove 58 bottom surface 59 inner peripheral surface 60 the diaphragm 61 diaphragm main body 62 seal member 63 support 64 stationary body 65 recess 66 annular protrusion 67 annular protrusion 68 annular ridges 69 valve seat

Claims (7)

A diaphragm valve that opens and closes a valve by pressing and separating the diaphragm against a valve seat portion. The diaphragm is sandwiched and fixed to a lower surface of the diaphragm body by a diaphragm main body made of a fluororesin and a support, and the valve seat A seal member made of an elastic body having a seal portion that is pressed against and separated from the portion ;
The seal portion of the seal member is an annular ridge provided on the outer edge of the seal member;
The valve seat portion is provided in the outer peripheral portion of the flow path formed in the center of the bottom surface of the valve chamber, and a step portion is provided in the inner peripheral edge portion of the valve seat portion,
A diaphragm valve , wherein the seal portion of the seal member is received in an annular groove formed by the outer peripheral surface of the support and the step portion when the valve is closed . 2. The diaphragm valve according to claim 1, wherein an outer diameter of the seal member in a state that is not when the valve is closed is provided to be slightly smaller than an inner diameter of the stepped portion of the valve seat portion. The diaphragm valve according to claim 1 or 2, wherein a concave portion is provided in the center of the lower surface of the diaphragm main body, and the upper surface of the seal member is fitted and fixed to the concave portion. The fixed body which consists of the same material as the said support body, The said sealing member and the said diaphragm main body are pinched | interposed and fixed by this support body and this fixed body, The Claim 1 to Claim 3 characterized by the above-mentioned. The diaphragm valve according to any one of the above. The diaphragm valve according to any one of claims 1 to 4, wherein an annular protrusion is provided on a contact surface of the diaphragm main body and / or the support member with the seal member. The protrusions are provided on the upper surface and / or the lower surface of the seal member, and the protrusions are fitted in the concave grooves provided in the diaphragm main body and / or the support body. 6. The diaphragm valve according to any one of items 5. The diaphragm valve according to any one of claims 1 to 6, wherein the sealing member includes a reinforcing cloth.

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