Valve device

Abstract

A valve device 1 comprises: a body 6 that has flow paths 18, 20, a recess 22, and a valve chamber 36; an inner disc 24 that has an inner peripheral edge 32 and an outer peripheral edge 34; a diaphragm 4; a first annular surface 44 that is formed on the side of the inner peripheral edge 32 which faces the valve chamber 36; a second annular surface 46 that is formed on the opposite side of the inner peripheral edge 32 from the first annular surface 44 and supported by the bottom surface 22a of the recess 22; a first seal portion 48 that is held on the first annular surface 44 and with which, or from which, the diaphragm 4 comes into contact, or separates; and a second seal portion 50 that is disposed between the second annular surface 46 and the bottom surface 22a of the recess 22.

Description

[Technical field]

[0001] The present invention relates to a valve device, and more particularly to a valve device having a diaphragm as a valve body. [Background technology]

[0002] Patent Document 1 discloses a diaphragm valve including a body having an inlet flow path for a fluid, an outlet flow path, and a recessed portion with an upward opening, a valve seat removably arranged on the periphery of the flow path formed in the body, a seat holder (also called an inner disk) removably arranged on the body and holding the valve seat, and a diaphragm that opens or closes the flow path by coming into and out of contact with the valve seat. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2015-36563 A Summary of the Invention [Problem to be solved by the invention]

[0004] The valve seat described in Patent Document 1 is an annular valve seat body that is attached to the inner peripheral surface of the inner peripheral edge of the inner disc and is made of a resin such as PCTFE (heat-resistant temperature: approximately 120°C). Therefore, when the temperature of the fluid flowing through the valve reaches a high temperature of, for example, 300°C or more, the valve seat that comes into contact with this high-temperature fluid must also have a similar level of heat resistance.

[0005] In addition, when the valve seat comes into contact with a high-temperature fluid and expands and then contracts, stress may be concentrated at the flange-shaped mounting portion that is attached to the inner peripheral portion of the inner disk of the valve seat. This stress concentration may cause deformation of the valve seat, and depending on the material, may cause the valve seat to crack or tear, which may impair the sealing performance of the valve.

[0006] Furthermore, the valve seat described in Patent Document 1 has a protruding valve seat portion against which the diaphragm abuts when the valve is closed, a flange-shaped mounting portion that is attached to the inner peripheral portion of the inner disk, and an abutment portion that abuts against the bottom surface of the recess in the valve body that houses the inner disk. A valve seat that has each of these portions is inevitably large in volume. Therefore, if such a valve seat with a large volume is exposed to high temperatures, the effects of thermal expansion become even more pronounced, and it may become even more difficult to ensure the sealing performance of the valve.

[0007] The present invention has been made in consideration of such problems, and has an object to provide a valve device that can ensure sealing performance by suppressing the effects of thermal expansion, even when a high-temperature fluid flows through the flow path. [Means for solving the problem]

[0008] In order to achieve the above-mentioned object, the valve device of the present invention comprises a body having a flow path, a recess in which the flow path is opened, and a valve chamber to which the flow path is connected at the recess; an inner disk housed in the recess and dividing the flow path up to the valve chamber by an inner circumferential edge and an outer circumferential edge; a diaphragm that blocks or connects the flow path in the valve chamber; a first annular surface formed on the side of the inner circumferential edge facing the valve chamber; a second annular surface formed on the side of the inner circumferential edge opposite the first annular surface and supported by a bottom surface of the recess; a first seal portion held by the first annular surface and against which the diaphragm abuts and disengages as the flow path is blocked or connected; and a second seal portion disposed between the second annular surface and the bottom surface of the recess, wherein the first seal portion and the second seal portion have an annular seat shape. Another valve device of the present invention includes a body having a flow passage, a recess into which the flow passage is opened, and a valve chamber with which the flow passage is communicated at the recess, and a valve body accommodated in the recess and partitioning the flow passage up to the valve chamber by an inner peripheral portion and an outer peripheral portion. An inner disk including a first inner disk and a second inner disk disposed radially inside the inner peripheral edge portion of the first inner disk so as to be movable in the thickness direction of the first inner disk and detachable therefrom. a diaphragm that opens or closes the flow path in the valve chamber; Second inner disc a first annular surface formed on a side facing the valve chamber; Second inner disca second annular surface formed on the opposite side to the first annular surface and supported by the bottom surface of the recess; a first seal portion held by the first annular surface and with which the diaphragm abuts and separates when the flow path is blocked or opened; and a second seal portion disposed between the second annular surface and the bottom surface of the recess. , within The valve further includes a pair of restricting portions formed on the inner peripheral surface of the side peripheral portion and the outer peripheral surface of the second inner disc, which abut against each other to restrict movement of the second inner disc in the thickness direction toward the valve chamber. Effect of the Invention

[0009] According to the valve device of the present invention, even when a high-temperature fluid flows through the flow passage, the effect of thermal expansion can be suppressed, thereby ensuring sealing performance. [Brief description of the drawings]

[0010] [Figure 1] 1 is a partial vertical cross-sectional view of a valve equipped with a valve device according to a first embodiment of the present invention. [Diagram 2] 2 is an enlarged longitudinal sectional view of the valve device in region A of FIG. 1. [Diagram 3] FIG. 2 is a vertical cross-sectional view of an inner disk. [Figure 4] FIG. [Diagram 5] FIG. 6 is a partial vertical cross-sectional view of a valve including a valve device according to a second embodiment of the present invention. [Figure 6] 6 is an enlarged longitudinal sectional view of a region B of FIG. 5 of the valve device. FIG. [Figure 7] FIG. 4 is a vertical cross-sectional view of a first inner disk to which a second inner disk is attached. [Figure 8] FIG. 2 is a top view of the first inner disk to which the second inner disk is attached. [Figure 9] FIG. 2 is a top view of the first inner disk. [Figure 10] FIG. 4 is a top view of the second inner disk. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, a valve device according to each embodiment of the present invention will be described with reference to the drawings. In the explanation of Fig. 1 to Fig. 3 and Fig. 5 to Fig. 7, the upper side of each figure is referred to as the upper side. First Embodiment 1 shows a partial vertical cross-sectional view of a valve 2 equipped with a valve device 1 according to a first embodiment of the present invention. The valve 2 is a direct-touch type metal diaphragm valve having a diaphragm 4 as a valve body, and capable of controlling minute flow rates of process fluid with high accuracy.

[0012] The valve 2 includes a body 6, a valve main body 8, a bonnet 10, a bonnet nut 12, a stem 14, an actuator 16, etc. The body 6 is formed from a metal material such as stainless steel, and is formed with an inlet flow path 18, an outlet flow path 20, and a recess 22 that opens upward. The inlet flow path 18 and the outlet flow path 20 open to a bottom surface 22a of the recess 22, and the valve main body 8 is housed therein. The valve device 1 is composed of the body 6 and the valve main body 8 housed in the recess 22 of the body 6.

[0013] Fig. 2 shows an enlarged vertical cross-sectional view of region A in Fig. 1 of the valve device 1. The valve body 8 is composed of the diaphragm 4, an inner disc 24, the lower end portion 10a of the bonnet 10, the lower expanded diameter portion 14a of the stem 14, a spring 26 (see Fig. 1), a diaphragm holder 28, a holder adapter 30, etc.

[0014] The diaphragm 4 is formed of one sheet or a stack of multiple separable thin plates, and these thin plates are formed in a dish shape with a central portion 4a of the diaphragm 4 bulging upward. The thin plate has an extremely thin thickness of, for example, about 0.1 mm to 0.2 mm, and is made of a metal material such as stainless steel or other shape memory alloys.

[0015] The inner disk 24 is formed from a metal material such as stainless steel, has an inner peripheral edge 32 and an outer peripheral edge 34, and is placed on the bottom surface 22a of the recess 22. The diaphragm 4 and the pressing adapter 30 are arranged in that order on the outer peripheral edge 34. The bonnet 10 is cylindrical, and is inserted into the recess 22. When the bonnet nut 12 is tightened, the lower end 10a of the bonnet 10 is pressed against the pressing adapter 30. As a result, the peripheral edge 4b ​​of the diaphragm 4 is pressed against the outer peripheral edge 34 of the inner disk 24 by the pressing adapter 30 and held therein.

[0016] The stem 14 is inserted into the bonnet 10 so as to be movable up and down, and a diaphragm retainer 28 made of a resin material or the like is fitted into the lower expanded diameter portion 14a. The diaphragm retainer 28 abuts against the upper surface of the radial center portion 4a of the diaphragm 4, and in the open state of Figure 1, presses the diaphragm 4 from above, preventing it from bending excessively. The upper part of the stem 14 protrudes from the upper part of the bonnet 10, and is inserted into the actuator 16.

[0017] The actuator 16 is, for example, an air-operated drive mechanism, which moves the stem 14 up and down by the elastic force of a coil spring 26 arranged in the recess 22 and the pressure of the operating air supplied to the actuator 16. For example, when the supply of operating air to the actuator 16 is cut off, the elastic force of the spring 26 acts on the lower expanded diameter portion 14a, lowering the stem 14, which then descends and presses the central portion 4a of the diaphragm 4 against the diaphragm presser 28, causing the diaphragm 4 to close the opening of the inlet flow passage 18, resulting in a closed valve state.

[0018] On the other hand, by supplying operating air to the actuator 16, the stem 14 rises, and the lower expanded diameter portion 14a rises against the elastic force of the spring 26. As a result, as shown in Figure 2, the diaphragm retainer 28 also rises, the diaphragm 4 returns to its natural upwardly curved state, the inlet flow path 18 opens, and the valve 2 enters an open state.

[0019] A valve chamber 36, which communicates with the inlet flow passage 18 and the outlet flow passage 20, is formed in the recess 22. The valve chamber 36 is surrounded by the retainer adapter 30, the diaphragm retainer 28, and the inner disk 24, and is an area into which fluid flows from the inlet flow passage 18. The diaphragm 4 is curved and deformed in the valve chamber 36 to block or communicate the inlet and outlet flow passages 18, 20.

[0020] Fig. 3 shows a vertical cross-sectional view of the inner disc 24, and Fig. 4 shows a top view of the inner disc 24. As shown in Fig. 2, the inner disc 24 is housed in the recess 22, and defines the inlet and outlet flow paths 18, 20 up to the valve chamber 36 by an inner periphery 32 and an outer periphery 34.

[0021] 4, the inner disc 24 has a through hole 38 formed inside the inner peripheral edge 32, which communicates with the inlet flow passage 18, and an intermediate annular portion 40 is formed between the inner peripheral edge 32 and the outer peripheral edge 34. The intermediate annular portion 40 has a plurality of through holes 42 formed along its circumferential direction, and each of the through holes 42 communicates with the outlet flow passage 20. As a result, the inlet and outlet flow passages 18, 20 are defined by the inner disc 24 up to the valve chamber 36.

[0022] A first annular surface 44 is formed on the side of the inner peripheral portion 32 facing the valve chamber 36, i.e., on the upper surface of the inner peripheral portion 32 as viewed in Fig. 3. A second annular surface 46 is formed on the side opposite to the first annular surface 44, i.e., on the lower surface of the inner peripheral portion 32 as viewed in Fig. 3. As shown in Fig. 2, the second annular surface 46 is supported by the bottom surface 22a of the recess 22 via a second seal portion 50, which will be described later.

[0023] The first and second annular surfaces 44, 46 are flat surfaces forming an annular shape, and a first seal portion 48 is attached and held by adhesion or the like to the first annular surface 44. The diaphragm 4 abuts against and separates from the first seal portion 48 when the inlet and outlet flow paths 18, 20 are blocked or connected. A second seal portion 50 is disposed between the second annular surface 46 and the bottom surface 22a of the recess 22. The second seal portion 50 may be attached and held by adhesion or the like to the second annular surface 46 or the bottom surface 22a.

[0024] The first and second seal portions 48, 50 have an annular sheet shape, and are both made of fluororubber. More preferably, the first and second seal portions 48, 50 are made of fluororubber (for example, fluororubber material "Kalrez (registered trademark)" manufactured by DuPont) that can withstand high temperatures, such as temperatures of 300°C or higher, of the fluid flowing through the inlet and outlet flow paths 18, 20.

[0025] As shown in Fig. 3, an annular protrusion 52 is formed on the outer peripheral edge 34 so as to protrude toward the bottom surface 22a of the recess 22, i.e., toward the lower side in Fig. 3. This protrusion 52 is formed to a protruding height H in the thickness direction Y of the inner disc 24. When the bonnet nut 12 is tightened and the lower end portion 10a of the bonnet 10 is pressed against the pressing adapter 30, the tip of the protrusion 52 abuts against the bottom surface 22a of the recess 22 that it faces.

[0026] This contact of the protrusions 52 holds the outer peripheral edge 34 against the bottom surface 22a of the recess 22 and seals the outer peripheral edge 34. Furthermore, the second seal portion 50 is appropriately crushed between the second annular surface 46 and the bottom surface 22a of the recess 22.

[0027] As described above, in this embodiment, the first seal portion 48 functions as a valve seat portion of a conventional valve seat, with the diaphragm 4 coming into contact with or leaving the first seal portion 48 when the inlet and outlet flow paths 18, 20 are blocked or connected. On the other hand, the second seal portion 50 functions as a contact portion that comes into contact with the bottom surface 22a of the recess 22 of a conventional valve seat.

[0028] As described above, in this embodiment, the valve seat in the valve device 1 is formed from two different members, the first and second seal portions 48, 50, which are respectively disposed at separate locations on the first and second annular surfaces 44, 46. This eliminates the need for a flange-shaped mounting portion for the valve seat as in the conventional embodiment.

[0029] Since there is no mounting portion for the valve seat, the occurrence of deformation, cracking, tearing, etc. of the valve seat caused by stress concentration at the mounting portion is suppressed. Also, since the valve seat can be formed in a small volume without a mounting portion, the effect of thermal expansion can be suppressed even when high-temperature fluid flows through the valve device 1. Therefore, the sealing performance of the valve device 1 can be ensured.

[0030] Furthermore, by providing the second seal portion 50 having the function of acting as a contact portion that comes into contact with the bottom surface 22a of the recess 22, it is possible to avoid metal-to-metal contact between the inner disk 24 and the bottom surface 22a of the recess 22 of the body 6. This makes it possible to suppress the generation of particles due to metal-to-metal contact at the second annular surface 46, so that by applying the valve 2 to, for example, semiconductor manufacturing equipment, it is possible to greatly reduce the rate of defective semiconductors due to the inclusion of particles.

[0031] Furthermore, by forming the first and second seal portions 48, 50 in annular seat shapes, the valve seats can be formed with the minimum necessary volume within the range in which the above-mentioned functions of the first and second seal portions 48, 50 can be exerted. Therefore, even when a high-temperature fluid flows through the valve device 1, the effects of thermal expansion can be suppressed more effectively, and the sealing performance of the valve device 1 can be maintained more effectively.

[0032] Furthermore, by forming the first and second seal portions 48, 50 from fluororubber, the heat resistance of the valve seat can be improved compared to when it is made of resin. Here, since a rubber valve seat generally has a higher thermal expansion coefficient than a resin, when it comes into contact with a high-temperature fluid and thermally expands and then contracts, in the past, stress was likely to concentrate at the attachment portion of the valve seat to the inner peripheral portion of the inner disk.

[0033] However, in this embodiment, since there is no such mounting portion, the occurrence of stress concentration is suppressed. In particular, by forming the first and second seal portions 48, 50 from a fluororubber material such as the above-mentioned "Kalrez (registered trademark)", it is possible to realize the first and second seal portions 48, 50 that can withstand even when a high-temperature fluid of 300°C or more flows through the inlet and outlet flow paths 18, 20. Therefore, in this case, it is possible to realize a valve device 1 that ensures sealing performance while suppressing the effects of thermal expansion, and further has heat resistance of 300°C or more.

[0034] Furthermore, the protrusion 52 formed on the outer peripheral edge 34 is formed to have a protruding height H in the thickness direction Y. As a result, when the bonnet nut 12 is tightened and the lower end 10a of the bonnet 10 is pressed against the pressing adapter 30, the tip of the protrusion 52 abuts against the bottom surface 22a of the opposing recess 22.

[0035] The contact of the protrusions 52 holds the outer peripheral edge 34 against the bottom surface 22a of the recess 22 and seals the outer peripheral edge 34. At this time, by adjusting the protrusion height H in advance, the second seal portion 50 is appropriately crushed between the second annular surface 46 and the bottom surface 22a of the recess 22 of the body 6, thereby ensuring sealing between the second annular surface 46 and the opposing bottom surface 22a of the recess 22 at the second annular surface 46. Furthermore, generation of particles due to metal-to-metal contact between the second annular surface 46 and the bottom surface 22a of the recess 22 can be suppressed.

[0036] <Second embodiment> 5 shows a partial vertical cross-sectional view of a valve 2 equipped with a valve device 1 according to a second embodiment of the present invention. In the following description, the characteristic parts of the second embodiment will be mainly described, and the same components as those in the first embodiment will be given the same reference numerals in the drawings and may not be described.

[0037] The valve 2 is a direct touch type metal diaphragm valve including a diaphragm 4, a body 6, a valve main body 8, a bonnet 10, a bonnet nut 12, a stem 14, an actuator 16, etc. An inlet flow path 18, an outlet flow path 20, and a recess 22 are formed in the body 6, and the inlet flow path 18 and the outlet flow path 20 open to a bottom surface 22a of the recess 22, and the valve main body 8 is housed therein. The valve device 1 is composed of the body 6 and the valve main body 8 housed in the recess 22 of the body 6.

[0038] Fig. 6 shows an enlarged vertical cross-sectional view of region B in Fig. 5 of the valve device 1. The valve body 8 is made up of the diaphragm 4, a first inner disc 60, a second inner disc 62, the lower end portion 10a of the bonnet 10, the lower expanded diameter portion 14a of the stem 14, a spring 26 (see Fig. 5), a diaphragm holder 28, and a holder adapter 30. That is, the inner disc of this embodiment is made up of two members, the first inner disc 60 and the second inner disc 62.

[0039] The first inner disc 60 is formed from a metal material such as stainless steel, has an inner peripheral edge 64 and an outer peripheral edge 66, and is placed on the bottom surface 22a of the recess 22. The second inner disc 62 is formed from the same metal material as the first inner disc 60, and is disposed radially inside the inner peripheral edge 64, and the diaphragm 4 and the pressing adapter 30 are disposed on the outer peripheral edge 66 of the first inner disc 60, in that order.

[0040] By inserting the bonnet 10 into the recess 22 and tightening the bonnet nut 12, the lower end portion 10a of the bonnet 10 is pressed against the pressing adapter 30. As a result, the peripheral portion 4b of the diaphragm 4 is pressed against the outer peripheral portion 66 of the first inner disc 60 by the pressing adapter 30 and held therein.

[0041] Fig. 7 shows a vertical cross-sectional view of the first inner disc 60 with the second inner disc 62 assembled, and Fig. 8 shows a top view of the first inner disc 60 with the second inner disc 62 assembled. As shown in Fig. 6, the first inner disc 60 is housed in the recess 22, and defines the inlet and outlet flow paths 18, 20 up to the valve chamber 36 by an inner periphery 64 and an outer periphery 66.

[0042] The second inner disk 62 has an annular shape with a through hole 68 formed therein, and is disposed inside the radial direction X of the inner peripheral edge portion 64 of the first inner disk 60 so as to be movable in the thickness direction Y of the first inner disk 60 and detachable from the first inner disk 60. Restricting portions 70, 72 are formed on the inner peripheral surface of the inner peripheral edge portion 64 and the outer peripheral surface of the second inner disk 62, respectively, so as to protrude in the radial direction X. The pair of restricting portions 70, 72 come into contact with each other, thereby restricting movement of the second inner disk 62 in the thickness direction Y towards the valve chamber 36.

[0043] 9 shows a top view of the first inner disk 60. A through hole 74 is formed on the inside of the inner peripheral edge 64 of the first inner disk 60. The through hole 74 communicates with the inlet flow passage 18 via the through hole 68 of the second inner disk 62. In addition, an intermediate annular portion 76 is formed between the inner peripheral edge 64 and the outer peripheral edge 66. A plurality of through holes 78 are formed in the intermediate annular portion 76 along its circumferential direction, and each of the through holes 78 communicates with the outlet flow passage 20. As a result, the inlet and outlet flow passages 18, 20 are defined in the first inner disk 60 up to the valve chamber 36.

[0044] Fig. 10 shows a top view of the second inner disc 62. A first annular surface 80 is formed on the side of the second inner disc 62 facing the valve chamber 36, i.e., on the upper surface of the second inner disc 62 as viewed in Fig. 7. A second annular surface 82 is formed on the side opposite to the first annular surface 80, i.e., on the lower surface of the second inner disc 62 as viewed in Fig. 7. As shown in Fig. 6, the second annular surface 82 is supported by the bottom surface 22a of the recess 22 via a second seal portion 86, which will be described later.

[0045] The first and second annular surfaces 80, 82 are flat surfaces forming an annular shape, and a first seal portion 84 is affixed to and held on the first annular surface 80 by adhesive or the like. The diaphragm 4 abuts against and separates from the first seal portion 84 when the inlet and outlet flow paths 18, 20 are blocked or connected. A second seal portion 86 is disposed between the second annular surface 82 and the bottom surface 22a of the recess 22. The second seal portion 86 is affixed to and held on the second annular surface 82 by adhesive or the like.

[0046] The first and second seal portions 84, 86 have annular projection shapes, i.e., ridges, protruding from the first annular surface 80 and the second annular surface 82, respectively, and are both made of fluororubber. More preferably, the first and second seal portions 84, 86 are made of fluororubber (for example, the fluororubber material "Kalrez (registered trademark)" manufactured by DuPont) that can withstand high temperatures, such as temperatures of 300°C or higher, of the fluid flowing through the inlet and outlet flow paths 18, 20.

[0047] Furthermore, a third annular surface 88 is formed on the first inner disc 60 on the side of the inner peripheral edge 64 facing the valve chamber 36, i.e., on the upper surface of the first inner disc 60 as viewed in Figure 7. Further, a fourth annular surface 90 is formed on the side opposite to the third annular surface 88, i.e., on the lower surface of the first inner disc 60 as viewed in Figure 7.

[0048] 6, the third annular surface 88 is substantially flush with the first annular surface 80 in the radial direction X when the pair of restricting portions 70, 72 are in contact with each other. Also, as shown in Fig. 7, the second seal portion 86 protrudes toward the bottom surface 22a of the recess 22 at a protruding height H that is greater than the height at which the second seal portion 86 is flush with the fourth annular surface 90 in the radial direction X when the pair of restricting portions 70, 72 are in contact with each other. As a result, the fourth annular surface 90 is spaced apart from the bottom surface 22a of the recess 22 as shown in Fig. 6.

[0049] 7, an annular protrusion 92 is formed on the outer peripheral edge 66 so as to protrude toward the bottom surface 22a of the recess 22, i.e., toward the lower side in FIG. 7. This protrusion 92 is formed to a protruding height H1 in the thickness direction Y. When the bonnet nut 12 is tightened and the lower end portion 10a of the bonnet 10 is pressed against the pressing adapter 30, the tip of the protrusion 92 abuts against the bottom surface 22a of the recess 22 that it faces.

[0050] This contact of the protrusions 92 holds the outer peripheral edge 66 against the bottom surface 22a of the recess 22 and seals the outer peripheral edge 66. Furthermore, the second seal portion 86 is appropriately crushed between the second annular surface 82 and the bottom surface 22a of the recess 22.

[0051] As described above, the valve device 1 of this embodiment includes the second inner disc 62 disposed movably in the thickness direction Y of the first inner disc 60 on the inside in the radial direction X of the inner peripheral edge portion 64 of the first inner disc 60. The first and second annular surfaces 80, 82 of the second inner disc 62 hold the first seal portion 84 and the second seal portion 86, respectively.

[0052] The first seal portion 84 functions as a valve seat portion of a conventional valve seat, with the diaphragm 4 coming into contact with or leaving the first seal portion 84 when the inlet and outlet flow paths 18, 20 are blocked or connected. On the other hand, the second seal portion 86 functions as a contact portion that comes into contact with the bottom surface 22a of the recess 22 of a conventional valve seat.

[0053] As described above, in this embodiment, the valve seat in the valve device 1 is formed from two different members, the first and second seal portions 84, 86, which are provided at separate locations on the first and second annular surfaces 80, 82. This eliminates the need for a flange-shaped mounting portion for the valve seat as in the conventional embodiment.

[0054] Since there is no mounting portion for the valve seat, the occurrence of deformation, cracking, tearing, etc. of the valve seat caused by stress concentration at the mounting portion is suppressed. Also, since the valve seat can be formed in a small volume without a mounting portion, the effect of thermal expansion can be suppressed even when high-temperature fluid flows through the valve device 1. Therefore, the sealing performance of the valve device 1 can be ensured.

[0055] Furthermore, by providing the second seal portion 86 having the function of acting as a contact portion that comes into contact with the bottom surface 22a of the recess 22, it is possible to avoid metal-to-metal contact between the second inner disk 62 and the bottom surface 22a of the recess 22 of the body 6. This makes it possible to suppress the generation of particles due to metal-to-metal contact at the second annular surface 82, so that by applying the valve 2 to, for example, semiconductor manufacturing equipment, it is possible to greatly reduce the rate of defective semiconductors due to the inclusion of particles.

[0056] Furthermore, the second inner disk 62 is movable relative to the first inner disk 60 within a range restricted in the thickness direction Y by the pair of restricting portions 70, 72. As a result, in a closed valve state in which the diaphragm 4 abuts against the first sealing portion 84, the second sealing portion 86 is pressed against the bottom surface 22a of the recess 22, and the second sealing portion 86 provides a reliable seal to prevent fluid from flowing out to the outlet flow path 20.

[0057] Moreover, the second inner disc 62 is detachable from the first inner disc 60. As a result, in the event that the first and second seal portions 84, 86 deteriorate over time, the second inner disc 62 equipped with new first and second seal portions 84, 86 can be replaced with a new one. It is therefore possible to provide a valve device 1 that is capable of maintaining its sealing performance even with long-term use.

[0058] Furthermore, by forming the first and second seal portions 84, 86 as ridges protruding from the first annular surface 80 and the second annular surface 82, respectively, it is possible to form the valve seat with the minimum necessary volume within the range in which the above-mentioned functions of the first and second seal portions 84, 86 can be exerted. Therefore, even when a high-temperature fluid flows through the valve device 1, the effects of thermal expansion can be suppressed more effectively, and the sealing performance of the valve device 1 can be maintained more effectively.

[0059] In particular, by forming the first seal portion 84 as a ridge, the diaphragm 4 is more likely to come into contact with it when the valve is closed, improving the ability to close the valve 2. Also, by forming the first and second seal portions 84, 86 from fluororubber, the heat resistance of the valve seat can be improved compared to when it is made of resin. Here, since a rubber valve seat generally has a higher thermal expansion coefficient than a resin valve seat, when it comes into contact with a high-temperature fluid and then thermally expands and contracts, in the past, stress was likely to concentrate at the attachment portion of the valve seat to the inner peripheral portion of the inner disk.

[0060] However, in this embodiment, since there is no such mounting portion, the occurrence of stress concentration is suppressed. In particular, by forming the first and second seal portions 84, 86 from a fluororubber material such as the above-mentioned "Kalrez (registered trademark)", it is possible to realize the first and second seal portions 84, 86 that can withstand even when a high-temperature fluid of 300°C or more flows through the inlet and outlet flow paths 18, 20. Therefore, in this case, it is possible to realize a valve device 1 that ensures sealing performance while suppressing the effects of thermal expansion, and further has heat resistance of 300°C or more.

[0061] Furthermore, the third annular surface 88 of the inner peripheral edge portion 64 of the first inner disc 60 is substantially flush with the first annular surface 80 in the radial direction X when the pair of restricting portions 70, 72 are in contact with each other. This prevents the second inner disc 62 from protruding excessively from the valve chamber 36, ensures the volume of the valve chamber 36, and does not obstruct the flow of fluid in the valve chamber 36.

[0062] Furthermore, the second seal portion 86 protrudes toward the bottom surface 22a of the recess 22 at a protruding height H that is greater than the height at which the second seal portion 86 is flush with the fourth annular surface 90 in the radial direction X when the pair of restricting portions 70, 72 are in contact with each other. As a result, the fourth annular surface 90 is spaced apart from the bottom surface 22a of the recess 22 as shown in Fig. 6, so that generation of particles due to metal-to-metal contact between the fourth annular surface 90 and the bottom surface 22a of the recess 22 can be suppressed.

[0063] Furthermore, the protrusion 92 formed on the outer peripheral edge 66 is formed to have a protruding height H1 in the thickness direction Y. As a result, when the bonnet nut 12 is tightened and the lower end 10a of the bonnet 10 is pressed against the pressing adapter 30, the tip of the protrusion 92 comes into contact with the bottom surface 22a of the opposing recess 22.

[0064] The contact of the protrusions 92 holds the outer peripheral edge 66 against the bottom surface 22a of the recess 22 and seals the outer peripheral edge 66. At this time, by adjusting the protrusion height H1 in advance, the second seal portion 86 is appropriately crushed between the bottom surface 22a of the recess 22, and the second annular surface 82 ensures sealing between the second annular surface 82 and the opposing bottom surface 22a of the recess 22 of the body 6. Furthermore, generation of particles due to metal-to-metal contact between the second annular surface 82 and the bottom surface 22a of the recess 22 can be suppressed.

[0065] This concludes the explanation of the embodiments of the present invention, but the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention. For example, in the first embodiment, so long as the first and second seal portions 48, 50 have the necessary functions with a relatively small volume while still being able to ensure the flow rate of the fluid in the valve chamber 36, the shapes of the first and second seal portions 48, 50 are not limited to the sheet shape. For example, at least the first seal portion 48 may be formed as a protrusion protruding from the first annular surface 44. This ensures that the diaphragm 4 comes into contact only with the first seal portion 48 when the valve is closed.

[0066] Similarly, in the second embodiment, so long as the first and second seal portions 84, 86 can have the necessary functions with a relatively small volume while still ensuring the flow rate of the fluid in the valve chamber 36, the shapes of the first and second seal portions 84, 86 are not limited to ribs. For example, the first and second seal portions 84, 86 may be in the form of an annular sheet, or may be in the form of a semicircular cross-sectional rib provided on the annular sheet with a step.

[0067] In each embodiment, the members constituting the valve device 1 and therefore the valve 2 are not limited to the materials described above, except for the inner disc 24, the first and second inner discs 60, 62, the first seal portions 48, 84, and the second seal portions 50, 86. In addition, the valve device 1 is driven by the actuator 16, which is an air-operated drive mechanism, but is not limited to this, and the valve device 1 is applicable to valves 2 having various drive mechanisms. [Explanation of symbols]

[0068] 1 Valve device 4 Diaphragm 4b Periphery 6. Body 18 Inlet channel (channel) 20 Outlet flow path (flow path) 22 Recess 22a Bottom 24 Inner disc 32, 64 Inner periphery 34, 66 outer periphery 36 Valve chamber 44, 80 First annular surface 46, 82 Second annular surface 48, 84 First seal part 50, 86 Second seal part 52, 92 protrusion 60 First inner disc (inner disc) 62 Second inner disc (inner disc) 70, 72 Regulatory Department 88 3rd Circular Plane 90 Fourth Circular Plane

Claims

1. a body having a flow passage, a recess into which the flow passage is opened, and a valve chamber with which the flow passage is communicated at the recess; an inner disk that is received in the recess and that has an inner peripheral portion and an outer peripheral portion that define the flow path up to the valve chamber; a diaphragm that blocks or communicates the flow path in the valve chamber; a first annular surface formed on a side of the inner peripheral portion facing the valve chamber; a second annular surface formed on the inner peripheral portion opposite the first annular surface and supported by a bottom surface of the recess; a first seal portion that is held by the first annular surface and with which the diaphragm abuts or leaves in response to interruption or establishment of the flow path; a second seal portion disposed between the second annular surface and a bottom surface of the recess; Equipped with The valve device, wherein the first seal portion and the second seal portion have an annular seat shape.

2. a body having a flow passage, a recess into which the flow passage is opened, and a valve chamber with which the flow passage is communicated at the recess; an inner disk including a first inner disk that is accommodated in the recess and that defines the flow path up to the valve chamber by an inner peripheral portion and an outer peripheral portion, and a second inner disk that is disposed radially inside the inner peripheral portion so as to be movable in a thickness direction of the first inner disk and detachable; a diaphragm that blocks or communicates the flow path in the valve chamber; a first annular surface formed on a side of the second inner disk facing the valve chamber; a second annular surface formed on the second inner disk opposite to the first annular surface and supported by a bottom surface of the recess; a first seal portion that is held by the first annular surface and with which the diaphragm abuts or leaves in response to interruption or establishment of the flow path; a second seal portion disposed between the second annular surface and a bottom surface of the recess; Equipped with the valve device further comprising a pair of regulating portions formed on an inner peripheral surface of the inner peripheral edge portion and an outer peripheral surface of the second inner disc, the pair of regulating portions abutting against each other to regulate movement of the second inner disc in the thickness direction toward the valve chamber.

3. The valve device according to claim 2 , wherein the first seal portion and the second seal portion form protrusions protruding from the first annular surface and the second annular surface, respectively.

4. the first inner disk includes a third annular surface formed on a side of the inner peripheral edge portion facing the valve chamber, The valve device according to claim 2 , wherein the third annular surface is substantially flush with the first annular surface in a radial direction when the pair of restricting portions are in contact with each other.

5. the first inner disk includes a fourth annular surface formed on the inner peripheral portion opposite the first annular surface and facing a bottom surface of the recess; 5. The valve device according to claim 2, wherein the second seal portion protrudes toward a bottom surface of the recess at a protruding height that is greater than a height at which the second seal portion is radially flush with the fourth annular surface when the pair of regulating portions abut against each other.

6. The valve device according to claim 1 , wherein the first seal portion and the second seal portion are made of fluororubber.

7. The valve device according to claim 1 , wherein the outer peripheral edge portion has a protrusion that protrudes toward a bottom surface of the recess in a thickness direction of the inner disk.

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