Fluid device

Abstract

To restrain a failure in which a dielectric breakdown occurs in a diaphragm part, and a fluid flowing through a fluid flow passage flows out of the diaphragm part.SOLUTION: A shut-off valve 100 comprises: a valve element part 160 capable of moving along an axis X1; a main body part 110 inside which a valve hole 113a, and a valve chest 114 for passing a fluid are formed; a diaphragm part 170 comprising a thin film part 171 formed in an annular shape around the axis X1 so as to isolate the valve chest 114 and an adjacent space S1, and a base part 172 connected to an outer peripheral side of the thin film part 171; a static elimination part 190 arranged while being sandwiched between the main body part 110 and the base part 172 in a direction along the axis X1; and a conduction part 140 in contact with the static elimination part 190, and kept at a ground potential. The static elimination part 190 is formed of a conductive fluorocarbon resin material containing a fluorocarbon resin material and a conductive material dispersed in the fluorocarbon resin material, and comprises an exposed part 191 exposed to the valve chest 114.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a fluid device. [Background technology]

[0002] Fluororesin materials have excellent chemical resistance and contamination resistance, and are therefore widely used in fluidic devices that circulate corrosive fluids used in semiconductor manufacturing, pure water, etc. Fluidic devices that adjust the flow rate of a fluid flowing through a fluid flow path by adjusting the position of a valve body that is close to or far from a valve hole include fluidic devices in which a thin-film diaphragm that separates the fluid flow path from an adjacent space is connected to the valve body.

[0003] In fluidic devices having a diaphragm portion made of a fluororesin material, if static electricity is generated inside due to friction between the fluid and the fluid flow path, the fluororesin material forming the thin-film diaphragm portion may suffer dielectric breakdown, causing the fluid flowing through the fluid flow path to leak out of the diaphragm portion. Patent Document 1 discloses that the diaphragm portion is formed of a conductive fluororesin material and maintained at ground potential, thereby preventing the diaphragm portion from suffering dielectric breakdown. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6106794 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the fluidic device disclosed in Patent Document 1 increases manufacturing costs because the diaphragm and the valve body connected to the diaphragm are entirely made of a conductive fluororesin material. Furthermore, although contamination of the fluid in contact with the diaphragm is suppressed by adjusting the proportion of carbon nanotubes contained in the conductive fluororesin material, the contact area between the fluid and the diaphragm and valve body is large, so it may not be possible to completely prevent metal ions from eluting from the carbon nanotubes and contaminating the fluid.

[0006] The present invention has been made in consideration of the above circumstances, and aims to provide a fluid device that suppresses the problem of the thin-film diaphragm portion experiencing insulation breakdown, causing the fluid flowing through the fluid flow path to leak out of the diaphragm portion. [Means for solving the problem]

[0007] In order to solve the above problems, the present invention employs the following means. a main body portion having a valve hole to which the valve body approaches or moves away and a fluid flow path through which a fluid flows; a thin film portion connected to the outer peripheral surface of the valve body portion and formed in an annular shape around the axis to separate a valve chamber in which the valve body portion is disposed and an adjacent space adjacent to the valve chamber; and a base portion connected to the outer peripheral side of the thin film portion and formed in an annular shape around the axis; a static eliminator portion formed in an annular shape around the axis and disposed in a state sandwiched between the main body portion and the base in a direction along the axis; and a conductive portion in contact with the static eliminator portion and maintained at ground potential, wherein the static eliminator portion is formed of a conductive fluororesin material containing a fluororesin material and a conductive material dispersed in the fluororesin material, and forms a part of the valve chamber.

[0008] According to one aspect of the present invention, a fluid device includes a static eliminator made of a conductive fluororesin material, sandwiched between a main body having a fluid flow path formed therein and a base of a diaphragm connected to the outer peripheral surface of a valve body. Positive charges generated in the fluid due to friction between the diaphragm and the fluid are eliminated through an exposed portion of the static eliminator, which is maintained at ground potential by a conductive portion, and negative charges in the diaphragm are also eliminated. This prevents dielectric breakdown of the thin-film diaphragm, which would otherwise cause fluid flowing through the fluid flow path to leak out of the diaphragm. Furthermore, compared to when the diaphragm and valve body are entirely made of a conductive fluororesin material, the contact area between the conductive fluororesin material and the fluid is reduced, preventing fluid contamination due to metal ions eluting from the conductive fluororesin material.

[0009] In one aspect of the fluid device of the present invention, the static eliminator has a housing portion that houses the base on its inner periphery in a radial direction perpendicular to the direction along the axis, and it is preferable that the base and the static eliminator are arranged with the outer periphery of the base and the inner periphery of the housing portion in contact with each other.

[0010] According to the fluid device of the above configuration, the outer peripheral surface of the base and the inner peripheral surface of the accommodating portion are arranged in contact with each other, thereby reliably preventing the base from moving radially outward and changing its radial position.

[0011] In a fluid device having the above configuration, a first annular protrusion portion is formed on the radial outer edge of the base portion, protruding toward the static eliminator portion and formed in a ring shape around the axis, and a first annular groove portion is formed in a ring shape around the axis in the area of ​​the static eliminator portion facing the first annular protrusion portion, and it is preferable that the base portion and the static eliminator portion are arranged with the first annular protrusion portion inserted into the first annular groove portion.

[0012] According to the fluid device of the above aspect, the first annular protrusion formed on the radial outer edge of the base is inserted into the first annular groove formed in the static eliminator, thereby forming a sealed area around the entire axis, which can reliably prevent fluid from leaking out from between the base and the static eliminator.

[0013] In the fluid device of the above aspect, the exposed portion may be exposed to the valve chamber in a predetermined region in a direction along the axis, and the predetermined region may be included in a sealing region in which the first annular protrusion portion and the first annular groove portion are arranged in a direction along the axis.

[0014] In the fluid device of the above embodiment, the exposed portion of the static eliminator is exposed to the valve chamber in a predetermined area included in the sealing area where the first annular protrusion and the first annular groove are arranged in the axial direction. Because the exposed portion is located near the thin film portion of the diaphragm, static elimination of the positively charged fluid due to friction with the thin film portion can be ensured.

[0015] In the fluid device of the above aspect, the length of the predetermined region in the direction along the axis may be shorter than the length of the sealing region in the direction along the axis. By making the length of the predetermined region in the direction along the axis shorter than the length of the sealing region, the area of ​​the exposed portion can be reduced, and contamination of the fluid due to elution of metal ions from the conductive fluororesin material can be prevented.

[0016] In a fluid device having the above configuration, the static eliminator has a second annular protrusion that protrudes toward the main body and is formed in a ring shape around the axis, and a second annular groove that is formed in a ring shape around the axis in an area of ​​the main body facing the second annular protrusion, and it is preferable that the static eliminator and the main body are arranged with the second annular protrusion inserted into the second annular groove.

[0017] According to the fluid device of the above aspect, the second annular protrusion formed on the static eliminator is inserted into the second annular groove formed on the main body, forming a sealed area around the entire axis, which can reliably prevent fluid from leaking out from between the static eliminator and the main body.

[0018] In the fluid device of the above aspect, it is preferable that the first annular protrusion, the first annular groove, the second annular protrusion, and the second annular groove are arranged at the same position in the radial direction.

[0019] According to the fluid device of the above embodiment, the load from the first annular protrusion toward the first annular groove is transmitted from the second annular protrusion to the second annular groove, thereby improving the sealing property of the sealing area formed by the second annular protrusion and the second annular groove.

[0020] In a fluid device having the above configuration, the main body portion is formed with a second annular protrusion portion that protrudes toward the static eliminator portion and is formed in a ring shape around the axis, and a second annular groove portion that is formed in a ring shape around the axis is formed in the area of ​​the static eliminator portion facing the second annular protrusion portion, and it is preferable that the main body portion and the static eliminator portion are arranged with the second annular protrusion portion inserted into the second annular groove portion.

[0021] According to the fluid device of the above aspect, the second annular protrusion formed on the main body is inserted into the second annular groove formed on the static eliminator, forming a sealed area around the entire axis, which can reliably prevent fluid from leaking out from between the static eliminator and the main body.

[0022] In the fluid device of the above aspect, it is preferable that the first annular protrusion, the first annular groove, the second annular protrusion, and the second annular groove are arranged at the same position in the radial direction.

[0023] According to the fluid device of the above embodiment, the load from the first annular protrusion toward the first annular groove is transmitted from the second annular groove to the second annular protrusion, thereby improving the sealing property of the sealing area formed by the second annular protrusion and the second annular groove.

[0024] In one aspect of the fluid device of the present invention, the conductive portion is an electric wire having a metal conductor formed in a linear shape and maintained at ground potential, and an insulator coating the conductor, and the main body portion is formed with a housing surface arranged in a ring shape around the axis so as to contact the outer peripheral surface of the static eliminator, and the housing surface is formed with a groove portion extending along the axis, and it is preferable that the conductor exposed at the tip of the conductive portion is housed in the groove portion so as to be conductive with the static eliminator.

[0025] According to the fluid device of the above configuration, the conductive part is an electric wire having a conductor and an insulator coating the conductor, and the conductor exposed at the tip of the conductive part is accommodated in a groove formed on the accommodation surface of the main body part, thereby making it possible to maintain the neutralization part at ground potential in a relatively simple manner.

[0026] In the fluid device having the above configuration, it is preferable that the conductor exposed at the tip of the conductive portion is fixed to the groove with an adhesive containing a conductive material.

[0027] According to the fluid device of the above aspect, the conductor exposed at the tip of the conductive portion is accommodated in the groove portion, and an adhesive containing a conductive material is injected into the groove portion and solidified, thereby enabling the conductor to be securely fixed in the groove portion while maintaining the conductor electrically connected to the static elimination portion. [Effects of the Invention]

[0028] According to the present invention, it is possible to provide a fluid device that suppresses the problem of a thin-film diaphragm portion experiencing dielectric breakdown and causing fluid flowing through a fluid flow path to flow out of the diaphragm portion. [Brief explanation of the drawings]

[0029] [Figure 1] 1 is a vertical cross-sectional view showing a shutoff valve according to a first embodiment of the present invention. [Figure 2] 2 is a partially enlarged view of part A of the shutoff valve shown in FIG. 1. [Figure 3] 3 is a partial enlarged view of part B of the shutoff valve shown in FIG. 2. [Figure 4] FIG. 10 is a partially enlarged view showing a modified example of the shutoff valve. [Figure 5] 1 is a graph showing the relationship between the amount of carbon nanotubes added and the volume resistivity of a conductive fluororesin material. [Figure 6] FIG. 4 is a vertical cross-sectional view showing a shutoff valve according to a second embodiment of the present invention. [Figure 7] FIG. 7 is a partial enlarged view of a portion C of the shutoff valve shown in FIG. 6. [Figure 8] 8 is a plan view of the shutoff valve shown in FIG. 7, seen from above with the upper housing removed. DETAILED DESCRIPTION OF THE INVENTION

[0030] [First embodiment] A shutoff valve (fluid device) 100 according to a first embodiment of the present invention will be described below with reference to the drawings. The shutoff valve 100 according to this embodiment is fluid device installed in a pipe through which a fluid (liquid such as a chemical solution or pure water) used in a semiconductor manufacturing device or the like flows. FIG. 1 is a vertical cross-sectional view showing the shutoff valve 100 according to the first embodiment of the present invention. FIG. 2 is a partial enlarged view of part A of the shutoff valve 100 shown in FIG. 1.

[0031] As shown in Figures 1 and 2, the shut-off valve 100 includes a main body portion 110, an upper housing 120, a lower housing 130, a conductive portion 140, a fastening bolt 150, a valve body portion 160, a diaphragm portion 170, a spring 180, and a static eliminator portion 190.

[0032] The main body 110 is a member having fluid flow paths (an inlet-side flow path 113, a valve chamber 114, and an outlet-side flow path 115, which will be described later) formed therein to guide fluid from an inlet 111 to an outlet 112. The main body 110 is made of a fluororesin material.

[0033] The fluid flow path formed inside the main body 110 has an inlet flow path 113, a valve chamber 114, and an outlet flow path 115. The fluid that flows into the inlet flow path 113 is guided to the valve chamber 114, and the fluid that is guided to the valve chamber 114 is guided to the outlet flow path 115. A valve hole 113a is formed at the end of the inlet flow path 113 on the valve chamber 114 side, and the valve body 160 moves close to or away from the valve hole 113a along the axis X1.

[0034] The upper housing 120 is a member that is disposed above the main body 110 and that houses the diaphragm 170 and the static eliminator 190 in the space formed between the upper housing 120 and the main body 110. The lower housing 130 is a member that is disposed below the main body 110 and that is installed on the installation surface S.

[0035] 1, the main body 110, the upper housing 120, and the lower housing 130 are integrated by fastening the upper housing 120 and the lower housing 130 together with the main body 110 sandwiched between them using fastening bolts 150. The upper housing 120 and the lower housing 130 are integrated together by, for example, four fastening bolts 150 arranged at equidistant positions from the axis X1.

[0036] The conductive part 140 is a metal member that is sandwiched between the main body 110 and the upper housing 120 in the direction along the axis X1. The conductive part 140 is attached in a state of contact with the static eliminator 190. The conductive part 140 is connected to the ground cable 10 that is maintained at ground potential, and is maintained at ground potential.

[0037] 1 and 2, the valve body 160 is formed in an axial shape along the axis X1 and is a member that moves close to or away from the valve hole 113a that guides fluid from the inlet-side flow path 113 to the valve chamber 114. The valve body 160 is movable along the axis X1 by the opposing force generated by the pressure chamber 121, which will be described later.

[0038] The shutoff valve 100 can be switched between a closed state in which the valve element 160 is brought close to the main body 110 until it comes into contact with the main body 110 to block the inflow of fluid from the valve hole 113a to the valve chamber 114, and an open state shown in Figures 1 and 2 in which the valve element 160 is separated from the main body 110. The valve chamber 114 is a space in which the valve element 160 is disposed, which communicates with the inlet-side flow path 113 and the outlet-side flow path 115, and which is formed between the main body 110 and the underside of the diaphragm 170.

[0039] 2, the diaphragm portion 170 is a member having a thin film portion 171 and a base portion 172. The thin film portion 171 is connected to the outer peripheral surface of the valve body portion 160 arranged in the valve chamber 114, and is formed in an annular shape around the axis X1 so as to separate the valve chamber 114 in which the valve body portion 160 is arranged from an adjacent space S1 adjacent to the valve chamber 114. The base portion 172 is connected to the outer peripheral side of the thin film portion 171, and is formed in an annular shape around the axis X1.

[0040] The diaphragm portion 170 is made of a fluororesin material and is formed integrally with the valve body portion 160. The thin film portion 171 is formed in an annular shape around the axis X1 and is formed as a thin film with a thickness of 0.2 mm to 0.5 mm. The thin film portion 171 has flexibility that allows it to deform in response to movement of the valve body portion 160 along the axis X1.

[0041] The spring (metal member) 180 is a metal (e.g., stainless steel) member that generates a biasing force in a direction along the axis X1 of the valve body 160 that moves the valve body 160 away from the valve hole 113a. The lower end of the spring 180 is disposed in contact with the upper housing 120, and the upper end of the spring 180 is disposed in contact with the piston portion 185. The lower end of the piston portion 185 is connected to the upper end of the valve body 160. Therefore, the biasing force generated by the spring 180 is transmitted to the upper end of the valve body 160 via the piston portion 185.

[0042] The static eliminator 190 is a member formed in an annular shape around the axis X1 and disposed in a state sandwiched between the main body 110 and the base 172 of the diaphragm 170 in the direction along the axis X1. The static eliminator 190 is formed from a conductive fluororesin material containing a fluororesin material and a conductive material dispersed in the fluororesin material. The static eliminator 190 has an exposed portion 191 that is exposed to the valve chamber 114 and forms part of the inner circumferential surface of the valve chamber 114.

[0043] Fig. 3 is a partial enlarged view of portion B of the shutoff valve 100 shown in Fig. 2. As shown in Fig. 3, the static eliminator 190 has a housing portion 192 that houses the base portion 172 on its inner circumferential side in a radial direction RD perpendicular to the direction along the axis X1. The base portion 172 and the static eliminator 190 are arranged with an outer circumferential surface 172a of the base portion 172 and an inner circumferential surface 192a of the housing portion 192 in contact with each other.

[0044] A first annular protrusion 172b that protrudes toward the static eliminator 190 and is formed in a ring shape around the axis X1 is formed on the outer edge of the base 172 in the radial direction RD. A first annular groove 193 that is formed in a ring shape around the axis X1 is formed in a region of the static eliminator 190 facing the first annular protrusion 172b.

[0045] The base 172 and the static eliminator 190 are arranged with the first annular protrusion 172b inserted into the first annular groove 193. The first annular protrusion 172b comes into contact with the first annular groove 193, thereby forming a sealed area around the entire circumference of the axis X1. This sealed area can reliably prevent fluid from leaking out from between the static eliminator 190 and the diaphragm 170.

[0046] The static eliminator 190 is formed with a second annular protrusion 194 that protrudes toward the main body 110 and is formed in a ring shape around the axis X1. A second annular groove 116 that is formed in a ring shape around the axis X1 is formed in a region of the main body 110 facing the second annular protrusion 194.

[0047] The static eliminator 190 and the main body 110 are arranged with the second annular protrusion 194 inserted into the second annular groove 116. The second annular protrusion 194 comes into contact with the second annular groove 116, forming a sealed area around the entire circumference of the axis X1. This sealed area can reliably prevent fluid from leaking out from between the static eliminator 190 and the main body 110.

[0048] 3, the first annular protrusion 172b, the first annular groove 193, the second annular protrusion 194, and the second annular groove 116 are arranged at the same position in the radial direction RD. The load from the first annular protrusion 172b toward the first annular groove 193 is transmitted from the second annular protrusion 194 to the second annular groove 116, thereby improving the sealing performance of the seal area formed by the second annular protrusion 194 and the second annular groove 116.

[0049] The exposed portion 191 is exposed to the valve chamber 114 in a predetermined region R1 along the axis X1. The predetermined region R1 is a region included in a sealing region R2 in which the first annular protrusion 172b and the first annular groove 193 are disposed along the axis X1. A length L1 of the predetermined region R1 along the axis X1 is shorter than a length L2 of the sealing region R2 along the axis X1. The length L1 is preferably set to, for example, 0.1 mm or more and 2.0 mm or less.

[0050] The shutoff valve 100 shown in Fig. 3 has the second annular protrusion 194 formed on the static eliminator 190 and the second annular groove 116 formed on the main body 110, but other configurations are also possible. For example, a modified example shown in Fig. 4 may be used. Fig. 4 is a partially enlarged view showing a modified example of the shutoff valve 100.

[0051] 4, a second annular protrusion 117 that protrudes toward the static eliminator 190 and is formed in an annular shape around the axis X1 is formed on the main body 110. A second annular groove 195 that is formed in an annular shape around the axis X1 is formed in a region of the static eliminator 190 facing the second annular protrusion 117.

[0052] The static eliminator 190 and the main body 110 are arranged with the second annular protrusion 117 inserted into the second annular groove 195. The second annular protrusion 117 comes into contact with the second annular groove 195, thereby forming a sealed area around the entire circumference of the axis X1. This sealed area can reliably prevent fluid from leaking out from between the static eliminator 190 and the main body 110.

[0053] 4, the first annular protrusion 172b, the first annular groove 193, the second annular protrusion 117, and the second annular groove 195 are arranged at the same position in the radial direction RD. The load from the first annular protrusion 172b toward the first annular groove 193 is transmitted from the second annular groove 195 to the second annular protrusion 117, thereby improving the sealing performance of the seal area formed by the second annular protrusion 117 and the second annular groove 195.

[0054] In the shutoff valve 100 of this embodiment, the main body 110, the upper housing 120, the lower housing 130, the valve body 160, and the diaphragm 170 are made of a fluororesin material that does not contain a conductive material. On the other hand, in the shutoff valve 100 of this embodiment, the static eliminator 190 is made of a fluororesin material that contains a conductive material.

[0055] Examples of fluororesin materials include PTFE (polytetrafluoroethylene), PCTFE (polychlorotrifluoroethylene), and PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer). As the fluororesin material, a powdered material (for example, PTFE G163 manufactured by Asahi Glass Co., Ltd.) can be used.

[0056] As the conductive material, for example, carbon nanotubes can be used. As the carbon nanotubes, it is desirable to use those having the following properties. - Fiber length is between 50 μm and 150 μm. - Fiber diameter is between 5nm and 20nm. 10mg / cm 3 or more and 70 mg / cm 3It has the following bulk density: The G / D ratio is between 0.7 and 2.0. -Purity is 99.5% or higher. -It is formed in multiple layers (for example, 4 to 12 layers). The fiber length of the carbon nanotubes is set to 50 μm or more so that when the carbon nanotubes are dispersed in a fluororesin material, a small amount is enough to provide sufficient conductivity.

[0057] The G / D ratio is the ratio of the G-band peak to the D-band peak that appear in the Raman spectrum of carbon nanotubes. The G-band is derived from the graphite structure, and the D-band is derived from defects. The G / D ratio indicates the ratio of the crystalline purity to the defect concentration of carbon nanotubes.

[0058] The inventors investigated the relationship between the amount of carbon nanotubes (wt%) dispersed in a fluororesin material and the volume resistivity (Ω·cm) of a conductive fluororesin material containing a fluororesin material and carbon nanotubes dispersed therein, and obtained the results shown in Figure 5. The results shown in Figure 5 were obtained by measuring the volume resistivity of a test piece in accordance with the "Test method for resistivity of conductive plastics using the four-probe method" specified in JIS K 7194.

[0059] Test pieces were prepared by melt-kneading the material in a kneading machine, then compression-molding it in a compression molding machine, and then cutting it into sizes conforming to JIS K 7194. The fluororesin material used to prepare the test pieces was PTFE G163 manufactured by Asahi Glass. A resistivity meter employing the four-probe method conforming to JIS K 7194 was used to measure the volume resistivity. The four-probe method involves contacting four needle-shaped probes (electrodes) with the test piece, and determining the resistance of the test piece from the current passed between the two outer probes and the potential difference generated between the two inner probes. The volume resistivity was calculated by averaging the measurements taken at multiple locations on each of the multiple test pieces.

[0060] According to the results shown in FIG. 5, by setting the amount of carbon nanotubes to be added in the range of 0.020 wt % or more and 0.030 wt % or less, the volume resistivity of the conductive fluororesin material can be increased to 1.0×10 3 Ω cm and greater than 1.0×10 4 This volume resistivity value is in the range of less than Ω·cm. This value is smaller than the volume resistivity value of the fluororesin material without carbon nanotubes dispersed therein (10 18 is significantly lower than the resistivity (Ω·cm).

[0061] The inventors used a shutoff valve 100 in which the static eliminator 190 was formed from a conductive fluororesin material with 0.025 wt % added carbon nanotubes, and measured the electrostatic voltage generated in the valve chamber 114 while circulating air at 50 kPa through the inlet flow path 113, the valve chamber 114, and the outlet flow path 115. The measurement result showed that the electrostatic voltage generated in the valve chamber 114 was maintained at approximately 0.2 kV.

[0062] On the other hand, using a comparative shutoff valve in which the static eliminator 190 was formed from a fluororesin material without carbon nanotubes added, the electrostatic voltage generated in the valve chamber 114 was measured while air of 50 kPa was circulating through the inlet flow path 113, the valve chamber 114, and the outlet flow path 115. The measurement result showed that the electrostatic voltage generated in the valve chamber 114 was maintained at approximately 3.0 kV or higher.

[0063] From the above results, in this embodiment, the conductive fluororesin material forming the static eliminator 190 contains carbon nanotubes at a ratio of 0.020% by weight or more and 0.030% by weight or less. The static eliminator 190 is connected to the ground cable 10 via the conductive part 140. This also makes it possible to obtain a conductive fluororesin material with a volume resistivity of 1.0×10 3 Ω cm and greater than 1.0×10 4 The resistance is in the range of less than Ω·cm, and the electrostatic voltage generated in the valve chamber 114 can be maintained at a low value of approximately 0.2 kV.

[0064] The actions and effects of the shutoff valve 100 of this embodiment described above will be described. According to the shutoff valve 100 of this embodiment, a static eliminator 190 made of a conductive fluororesin material is disposed between the main body 110, which has an inlet flow path 113, a valve chamber 114, and an outlet flow path 115 formed therein, and the base 172 of the diaphragm 170, which is connected to the outer circumferential surface of the valve body 160. Positive charges generated in the fluid due to friction between the diaphragm 170 and the fluid are eliminated via the exposed portion 191 of the static eliminator 190, which is maintained at ground potential by the conductive portion 140, and accordingly, negative charges in the diaphragm 170 are eliminated. This makes it possible to prevent dielectric breakdown of the thin-film diaphragm 170 and the fluid flowing through the valve chamber 114 from leaking out of the diaphragm 170. Furthermore, compared to when the entire diaphragm portion 170 and valve body portion 160 are formed from a conductive fluororesin material, the contact area between the conductive fluororesin material and the fluid is reduced, making it possible to prevent contamination of the fluid due to metal ions eluting from the conductive fluororesin material.

[0065] According to the shut-off valve 100 of this embodiment, the outer peripheral surface 172a of the base 172 and the inner peripheral surface 192a of the accommodating portion 192 are arranged in contact with each other, so that the base 172 can be reliably prevented from moving outward in the radial direction RD and changing the position of the base 172 in the radial direction RD.

[0066] According to the shutoff valve 100 of this embodiment, the first annular protrusion 172b formed on the outer edge of the base 172 in the radial direction RD is disposed in a state inserted into the first annular groove 193 formed in the static eliminator 190, and a seal region R2 is formed around the entire circumference around the axis X1. This seal region R2 can reliably prevent fluid from leaking out from between the base 172 and the static eliminator 190.

[0067] According to the shutoff valve 100 of this embodiment, the exposed portion 191 of the charge eliminating portion 190 is exposed to the valve chamber 114 in a predetermined region R1 included in the sealing region R2 where the first annular protrusion 172b and the first annular groove 193 are arranged in the direction along the axis X1. Because the exposed portion 191 is located near the thin film portion 171 of the diaphragm portion 170, friction between the thin film portion 171 and the positively charged fluid can be reliably neutralized.

[0068] According to the shut-off valve 100 of this embodiment, by making the length L1 of the predetermined region R1 in the direction along the axis X1 shorter than the length L2 of the sealing region R2, the area of ​​the exposed portion 191 can be reduced, and contamination of the fluid due to elution of metal ions from the conductive fluororesin material can be prevented.

[0069] According to the shutoff valve 100 of this embodiment, the second annular protrusion 194 formed on the static eliminator 190 is disposed in a state inserted into the second annular groove 116 formed on the main body 110, and a sealed area is formed around the entire circumference of the axis X1. This sealed area can reliably prevent fluid from leaking out from between the static eliminator 190 and the main body 110.

[0070] According to the shut-off valve 100 of this embodiment, the load from the first annular protrusion 172b toward the first annular groove 193 is transmitted from the second annular protrusion 194 to the second annular groove 116, thereby improving the sealing performance of the sealing area formed by the second annular protrusion 194 and the second annular groove 116.

[0071] According to the shutoff valve 100 of this modified example of the present embodiment, the second annular protrusion 117 formed on the main body 110 is disposed in a state inserted into the second annular groove 195 formed on the static eliminator 190, and a sealed area is formed around the entire circumference of the axis X1. This sealed area can reliably prevent fluid from leaking out from between the static eliminator 190 and the main body 110.

[0072] According to the shut-off valve 100 of the modified example of this embodiment, the load from the first annular protrusion 172b toward the first annular groove 193 is transmitted from the second annular groove 195 to the second annular protrusion 117, thereby improving the sealing property of the sealing area formed by the second annular protrusion 117 and the second annular groove 195.

[0073] Second Embodiment Next, a shutoff valve 100A according to a second embodiment of the present invention will be described with reference to the drawings. This embodiment is a modification of the first embodiment, and unless otherwise specifically described below, it is assumed to be the same as the shutoff valve 100 of the first embodiment, and therefore the description below will be omitted.

[0074] The conductive part 140 provided in the shutoff valve 100 of the first embodiment is a metal member that is sandwiched between the main body 110 and the upper housing 120 in the direction along the axis X1. In contrast, the conductive part 140A provided in the shutoff valve 100A of the present embodiment is an electric wire having a conductor 141 and an insulator 142.

[0075] As shown in Fig. 6, the shutoff valve 100A of this embodiment has a conductive part 140A that is in contact with the static eliminator 190 and is maintained at ground potential. The conductive part 140A is disposed with an insulator 142 sandwiched between the main body 110 and the upper housing 120. As shown in Fig. 7, the conductive part 140A is an electric wire that has a conductor 141 that is maintained at ground potential and is formed into a linear shape and is made of metal (for example, copper), and an insulator 142 that is formed of an insulating material (for example, a resin material) that coats the conductor 141.

[0076] As shown in Fig. 8, the main body 110 is formed with a housing surface 110a that is formed in an annular shape around the axis X1 so as to be in contact with the outer peripheral surface 190a of the static eliminator 190. As shown in Fig. 7, the housing surface 110a is formed with a groove 110b that extends along the axis X1. The conductor 141 exposed at the tip of the conductive portion 140A is housed in the groove 110b so as to be electrically connected to the static eliminator 190.

[0077] 8, the conductor 141 exposed at the tip of the conductive portion 140A is fixed to the groove portion 110b with adhesive 143 containing a conductive material (for example, conductive silver particles). The adhesive 143 is injected into the groove portion 110b by an operator in a state where the tip of the conductive portion 140A, from which the insulator 142 has been removed and the conductor 141 is exposed, is placed in the groove portion 110b.

[0078] 7 and 8, an accommodation groove 110c extending in the radial direction RD is formed on the upper surface of the main body 110. The width W1 of the accommodation groove 110c is narrower than the width W2 of the conductive portion 140A in its natural state. Therefore, by pushing the conductive portion 140A into the accommodation groove 110c, the conductive portion 140A can be maintained accommodated in the accommodation groove 110c.

[0079] According to the shut-off valve 100A of this embodiment, the conductive portion 140A is an electric wire having a conductor 141 and an insulator 142 coating the conductor 141, and the conductor 141 exposed at the tip of the conductive portion 140A is accommodated in a groove portion 110b formed in the accommodation surface 110a of the main body portion 110, thereby making it possible to maintain the neutralization portion 190 at ground potential in a relatively simple manner.

[0080] Furthermore, according to the shut-off valve 100A of this embodiment, the conductor 141 exposed at the tip of the conductive portion 140A is accommodated in the groove portion 110b, and then adhesive 143 containing a conductive material is injected into the groove portion 110b and solidified, thereby making it possible to reliably fix the conductor 141 to the groove portion 110b while maintaining the conductor 141 electrically connected to the static eliminator 190.

[0081] Other Embodiments Although the above description has been given of the shutoff valve 100 as the fluid device, other fluid devices may be used. For example, other fluid devices may be used, such as a flow rate adjusting device that adjusts the flow rate of a fluid by adjusting the insertion amount of a needle valve into a valve hole. [Explanation of symbols]

[0082] 10 Ground Cable 100 Shut-off valve (fluid equipment) 110 Main body 111 Inlet 112 Outlet 113 Inlet flow path (fluid flow path) 113a Valve hole 114 Valve chamber (fluid flow path) 115 Outlet flow path (fluid flow path) 116 Second annular groove 117 Second annular protrusion 120 Upper housing 121 Pressure Chamber 130 Lower housing 140 Conductive part 150 Fastening bolt 160 Valve body 170 Diaphragm part 171 Thin Film Section 172 Base 172a Outer surface 172b First annular protrusion 180 Spring 185 Piston section 190 Static elimination unit 191 Exposed part 192 Storage Unit 192a Inner surface 193 First annular groove 194 Second annular protrusion 195 Second annular groove R1 Predetermined area R2 seal area RD radial direction S Installation surface S1 Adjacent space X1 axis

Claims

1. a valve body portion formed in a shaft shape so as to extend along an axis line and movable along the axis line; a main body portion having a valve hole, through which the valve body portion approaches or moves away from the valve body portion, and a fluid flow path, through which a fluid flows, formed therein; a diaphragm portion including: a thin film portion connected to an outer peripheral surface of the valve body portion and formed in an annular shape around the axis so as to separate a valve chamber in which the valve body portion is disposed from an adjacent space adjacent to the valve chamber; and a base portion connected to the outer peripheral side of the thin film portion and formed in an annular shape around the axis; a static eliminator formed in an annular shape around the axis and sandwiched between the main body and the base in a direction along the axis; a conductive part that is in contact with the static eliminator and is maintained at a ground potential, The static eliminator is a fluid device formed from a conductive fluororesin material containing a fluororesin material and a conductive material dispersed in the fluororesin material, and has an exposed portion exposed to the valve chamber.

2. the static eliminator has a housing portion that houses the base portion on an inner peripheral side in a radial direction perpendicular to the direction along the axis, The fluid device according to claim 1 , wherein the base and the static eliminator are arranged such that an outer circumferential surface of the base and an inner circumferential surface of the accommodating portion are in contact with each other.

3. a first annular protrusion portion that protrudes toward the static eliminator and is formed annularly around the axis on an outer edge of the base portion in the radial direction, a first annular groove formed in an annular shape around the axis in a region of the static eliminator facing the first annular protrusion, The fluid device according to claim 2 , wherein the base portion and the static eliminator are arranged with the first annular protrusion inserted into the first annular groove.

4. the exposed portion is exposed to the valve chamber in a predetermined region in a direction along the axis, The fluid device according to claim 3 , wherein the predetermined region is included in a sealing region in which the first annular protrusion and the first annular groove are disposed in the direction along the axis.

5. The fluid device according to claim 4 , wherein the length of the predetermined region in the direction along the axis is shorter than the length of the sealing region in the direction along the axis.

6. a second annular protrusion portion that protrudes toward the main body portion and is formed in an annular shape around the axis line on the static eliminator portion; a second annular groove formed in an annular shape around the axis in a region of the main body facing the second annular protrusion, The fluid device according to claim 3 , wherein the static eliminator and the main body are arranged with the second annular protrusion inserted into the second annular groove.

7. The fluid device according to claim 6 , wherein the first annular protrusion, the first annular groove, the second annular protrusion, and the second annular groove are arranged at the same position in the radial direction.

8. a second annular protrusion portion that protrudes toward the static eliminator and is formed annularly around the axis line on the main body portion; a second annular groove formed in an annular shape around the axis in a region of the static eliminator facing the second annular protrusion, The fluid device according to claim 3 , wherein the main body and the static eliminator are arranged with the second annular protrusion inserted into the second annular groove.

9. The fluid device according to claim 8 , wherein the first annular protrusion, the first annular groove, the second annular protrusion, and the second annular groove are arranged at the same position in the radial direction.

10. the conductive portion is an electric wire having a metal conductor formed in a linear shape and maintained at a ground potential, and an insulator coating the conductor, the main body portion has a housing surface that is arranged annularly around the axis so as to come into contact with an outer peripheral surface of the static eliminator, A groove extending along the axis is formed in the housing surface, The fluid device according to claim 1 , wherein the conductor exposed at the tip of the conductive portion is accommodated in the groove portion so as to be electrically connected to the static eliminator.

11. The fluid device according to claim 10 , wherein the conductor exposed at the tip of the conductive portion is fixed to the groove with an adhesive containing a conductive material.

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