Fluid device

Abstract

The purpose of the present invention is to suppress a malfunction in which a fluid flowing through a fluid flow path flows out of a diaphragm part due to insulation failure of the diaphragm part. The invention provides a shut-off valve, which comprises a valve body part capable of moving along an axis; a main body part in which a valve hole and a valve chamber through which a fluid flows are formed; a diaphragm section having a diaphragm section formed in a ring shape around the axis so that the valve chamber and the adjacent space are isolated, and a base section connected to the outer peripheral side of the diaphragm section; a static eliminating part disposed in a state of being sandwiched between the main body part and the base part in a direction along the axis; and a conduction part which is in contact with the static elimination part and is maintained at a ground potential, the static elimination part is formed by a conductive fluororesin material of a conductive material, and the conductive material comprises a fluororesin material and an exposed part which is dispersed in the fluororesin material and is exposed to the valve chamber.

Description

TECHNICAL FIELD

[0001] The present application relates to a fluid apparatus. BACKGROUND

[0002] A fluororesin material is widely used for a fluid apparatus that allows a corrosive fluid, pure water, or the like used in semiconductor manufacturing to flow, because of excellent chemical resistance and stain resistance. In addition, as a fluid apparatus that adjusts the flow rate of a fluid flowing in a fluid flow passage by adjusting the position of a valve body portion that approaches or departs from a valve hole, a fluid apparatus is known in which a diaphragm portion that separates a fluid flow passage and an adjacent space adjacent thereto is connected to the valve body portion.

[0003] In a fluid apparatus provided with a diaphragm portion formed of a fluororesin material, in a case where static electricity is generated inside due to friction between a fluid flow passage and a fluid, the fluororesin material that forms the diaphragm portion in a thin film shape can cause insulation breakdown, thereby causing an adverse situation in which a fluid flowing in the fluid flow passage flows out from the diaphragm portion. In Patent Literature 1, it is disclosed that insulation breakdown of the diaphragm portion is prevented by forming the diaphragm portion of an electroconductive fluororesin material and maintaining the diaphragm portion at a ground potential.

[0004] PRIOR ART DOCUMENTS

[0005] PATENT LITERATURE

[0006] Patent Literature 1: Japanese Patent No. 6106794 SUMMARY

[0007] PROBLEMS TO BE SOLVED BY THE INVENTION

[0008] However, in the fluid apparatus disclosed in Patent Literature 1, the entire diaphragm portion and the valve body portion connected to the diaphragm portion are formed of an electroconductive fluororesin material, and thus the manufacturing cost increases. In addition, although the proportion of carbon nanotubes contained in the electroconductive fluororesin material is adjusted to suppress contamination of a fluid in contact with the diaphragm portion, the contact area of the fluid with the diaphragm portion and the valve body portion is large, and thus it can not be possible to completely prevent contamination of the fluid by elution of metal ions from the carbon nanotubes.

[0009] The present application was completed in view of such circumstances, and aims to provide a fluid apparatus in which an adverse situation in which a fluid flowing in a fluid flow passage flows out from a diaphragm portion due to insulation breakdown of the diaphragm portion in a thin film shape is suppressed.

[0010] MEANS FOR SOLVING THE PROBLEMS

[0011] The present application adopts the following means in order to solve the above problems.

[0012] A fluid device according to one aspect of the present invention includes: a valve body portion formed in a shaft shape extending along an axis and movable along the axis; a main body portion in which a valve hole approaching or separating from the valve body portion and a fluid flow passage through which a fluid flows are formed; a diaphragm portion having a thin film portion coupled to an outer peripheral surface of the valve body portion and formed in a ring shape around the axis so as 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 coupled to an outer peripheral side of the thin film portion and formed in a ring shape around the axis; a de-electrification portion formed in a ring shape around the axis and disposed in a state of being sandwiched between the main body portion and the base portion in a direction along the axis; and a conduction portion in contact with the de-electrification portion and maintained at a ground potential, the de-electrification portion being formed of an electroconductive fluororesin material including a fluororesin material and an electroconductive material dispersed in the fluororesin material and forming a part of the valve chamber.

[0013] According to the fluid device of one aspect of the present invention, the de-electrification portion formed of the electroconductive fluororesin material is disposed in a state of being sandwiched between the main body portion in which the fluid flow passage is formed and the base portion coupled to the outer peripheral surface of the valve body portion. The positive charge generated in the fluid due to friction between the diaphragm portion and the fluid is de-electrified via the exposed portion of the de-electrification portion maintained at the ground potential by the conduction portion, and at the same time, the negative charge in the diaphragm portion is de-electrified. Therefore, it is possible to suppress the adverse situation in which the diaphragm portion in a thin film shape reaches dielectric breakdown and the fluid flowing in the fluid flow passage flows out from the diaphragm portion. In addition, compared with the case where the diaphragm portion and the valve body portion are formed of the electroconductive fluororesin material as a whole, it is possible to reduce the contact area of the electroconductive fluororesin material with the fluid and prevent contamination of the fluid due to elution of metal ions from the electroconductive fluororesin material.

[0014] In the fluid device of one aspect of the present invention, it is preferable that the de-electrification portion has a receiving portion that receives the base portion on an inner peripheral side in a radial direction orthogonal to the direction along the axis, and the base portion and the de-electrification portion are disposed in a state where an outer peripheral surface of the base portion is in contact with an inner peripheral surface of the receiving portion.

[0015] According to the fluid device having the above-described structure, since the base portion is disposed in a state where the outer peripheral surface of the base portion is in contact with the inner peripheral surface of the receiving portion, it is possible to reliably prevent the base portion from moving toward the outside in the radial direction and the position of the base portion in the radial direction from changing.

[0016] In the fluid apparatus of the above structure, it is preferable that a first annular protrusion portion protruding toward the de-electrification portion and formed in a ring shape around the axis be formed in the radially outer edge of the base portion, a first annular groove portion formed in a ring shape around the axis be formed in a region of the de-electrification portion opposite the first annular protrusion portion, and the base portion and the de-electrification portion be arranged with the first annular protrusion portion inserted into the first annular groove portion.

[0017] The fluid apparatus according to the above-described aspect is configured such that the first annular protrusion portion formed in the radially outer edge of the base portion is arranged in a state of being inserted into the first annular groove portion formed in the de-electrification portion, and a sealing region is formed around the entire circumference of the axis. With this sealing region, it is possible to reliably prevent fluid from flowing out between the base portion and the de-electrification portion.

[0018] In the fluid apparatus of the above aspect, the exposed portion can be exposed to the valve chamber in a prescribed region in the direction along the axis, the prescribed region being included in a sealing region in which the first annular protrusion portion and the first annular groove portion are arranged in the direction along the axis.

[0019] The fluid apparatus according to the above-described aspect is configured such that, in the direction along the axis, the exposed portion of the de-electrification portion is exposed to the valve chamber in a prescribed region included in a sealing region in which the first annular protrusion portion and the first annular groove portion are arranged. Since the exposed portion is present in the vicinity of the diaphragm portion of the thin film portion, it is possible to reliably de-electrify the thin film portion and fluid that has become positively charged by rubbing against the thin film portion.

[0020] In the fluid apparatus of the above aspect, a length of the prescribed region in the direction along the axis can be shorter than a length of the sealing region in the direction along the axis. By making the length of the prescribed region in the direction along the axis shorter than the length of the sealing region, it is possible to reduce the area of the exposed portion and prevent contamination of the fluid due to elution of metal ions from the electrically conductive fluororesin material.

[0021] In the fluid apparatus of the above structure, it is preferable that a second annular protrusion portion protruding toward the main body portion and formed in a ring shape around the axis be formed in the de-electrification portion, a second annular groove portion formed in a ring shape around the axis be formed in a region of the main body portion opposite the second annular protrusion portion, and the de-electrification portion and the main body portion be arranged with the second annular protrusion portion inserted into the second annular groove portion.

[0022] The fluid apparatus according to the above-described aspect is configured such that the second annular protrusion portion formed in the de-electrification portion is arranged in a state of being inserted into the second annular groove portion formed in the main body portion, and a sealing region is formed around the entire circumference of the axis. With this sealing region, it is possible to reliably prevent fluid from flowing out between the de-electrification portion and the main body portion.

[0023] In the fluid apparatus of the above aspect, it is preferable that the first annular protruding portion, the first annular groove portion, the second annular protruding portion, and the second annular groove portion are arranged at the same position in the radial direction.

[0024] In the fluid apparatus according to the above aspect, load from the first annular protruding portion toward the first annular groove portion is transmitted from the second annular groove portion to the second annular protruding portion, and thus the sealability of the seal region formed by the second annular protruding portion and the second annular groove portion can be improved.

[0025] In the fluid apparatus of the above aspect, it is preferable that a second annular protruding portion protruding toward the de-electrifying portion and formed in a ring shape around the axis is formed in the main body portion, a second annular groove portion formed in a ring shape around the axis is formed in a region of the de-electrifying portion opposite to the second annular protruding portion, and the main body portion and the de-electrifying portion are arranged with the second annular protruding portion inserted into the second annular groove portion.

[0026] In the fluid apparatus according to the above aspect, the second annular protruding portion formed in the main body portion is arranged so as to be inserted into the second annular groove portion formed in the de-electrifying portion, and a seal region is formed around the entire circumference of the axis. With this seal region, it is possible to reliably prevent fluid from flowing out from between the de-electrifying portion and the main body portion.

[0027] In the fluid apparatus of the above aspect, it is preferable that the first annular protruding portion, the first annular groove portion, the second annular protruding portion, and the second annular groove portion are arranged at the same position in the radial direction.

[0028] In the fluid apparatus according to the above aspect, load from the first annular protruding portion toward the first annular groove portion is transmitted from the second annular groove portion to the second annular protruding portion, and thus the sealability of the seal region formed by the second annular protruding portion and the second annular groove portion can be improved.

[0029] In the fluid apparatus of the above aspect, it is preferable that the lead-through portion is an electric wire having a conductor made of metal maintained at a ground potential and formed in a linear shape, and an insulator covering the conductor, a receiving surface arranged in a ring shape around the axis in a manner to contact an outer circumferential surface of the de-electrifying portion is formed in the main body portion, a groove portion extending along the axis is formed in the receiving surface, and the conductor exposed at a front end of the lead-through portion is received in the groove portion in a manner to be in conduction with the de-electrifying portion.

[0030] In the fluid apparatus of the above aspect, the electric wire having the conductor and the insulator covering the conductor is used as the lead-through portion, and the conductor exposed at the front end of the lead-through portion is received in the groove portion formed in the receiving surface of the main body portion, and thus it is possible to comparatively easily maintain the de-electrifying portion at the ground potential.

[0031] In the fluid device having the above structure, it is preferable that the conductor exposed at the front end of the conducting portion is fixed to the groove portion by an adhesive containing a conductive material.

[0032] According to the fluid device of the above-mentioned embodiment, while the conductor exposed at the front end of the conductive portion is housed in the groove, an adhesive containing a conductive material is injected into the groove and cured, thereby maintaining the electrical connection between the conductor and the static elimination portion and reliably fixing the conductor to the groove.

[0033] Effects of the Invention

[0034] According to the present invention, it is possible to provide a fluid device that suppresses the problem that a thin film diaphragm portion undergoes dielectric breakdown and a fluid flowing through a fluid flow path flows out of the diaphragm portion. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a longitudinal sectional view showing a stop valve according to a first embodiment of the present invention.

[0036] Figure 2 yes Figure 1 A partial enlarged view of part A of the stop valve is shown.

[0037] Figure 3 yes Figure 2 A partial enlarged view of part B of the stop valve is shown.

[0038] Figure 4 It is a partially enlarged view showing a modified example of the stop valve.

[0039] Figure 5 This is a graph showing the relationship between the amount of carbon nanotubes added and the volume resistivity of the conductive fluororesin material.

[0040] Figure 6 It is a longitudinal sectional view showing a stop valve according to a second embodiment of the present invention.

[0041] Figure 7 yes Figure 6 A partial enlarged view of part C of the stop valve is shown.

[0042] Figure 8 Viewed from above with the upper housing removed Figure 7 A top view of the shut-off valve is shown.

[0043] Description of Reference Numerals

[0044] 10 ground cable, 100 stop valve (fluid device), 110 main body portion, 111 inflow port, 112 outflow port, 113 inflow side flow passage (fluid flow passage), 113a valve hole, 114 valve chamber (fluid flow passage), 115 outflow side flow passage (fluid flow passage), 116 second annular groove portion, 117 second annular protrusion portion, 120 upper housing, 121 pressure chamber, 130 lower housing, 140 conduction portion, 150 fastening bolt, 160 valve body portion, 170 diaphragm portion, 171 thin film portion, 172 base portion, 172a outer peripheral surface, 172b first annular protrusion portion, 180 spring, 185 piston portion, 190 electric field elimination portion, 191 exposed portion, 192 housed portion, 192a inner peripheral surface, 193 first annular groove portion, 194 second annular protrusion portion, 195 second annular groove portion, R1 prescribed region, R2 sealing region, RD radial direction, S arrangement surface, S1 adjacent space, X1 axis DETAILED DESCRIPTION

[0045] [First Embodiment]

[0046] A stop valve (fluid device) 100 of a first embodiment of the present application will be described below with reference to the drawings. The stop valve 100 of the present embodiment is a fluid device provided to a pipe through which a fluid (liquid such as a chemical liquid or pure water) used in a semiconductor manufacturing apparatus or the like flows. Figure 1 is a longitudinal sectional view of the stop valve 100 of the first embodiment of the present application. Figure 2 is Figure 1 is an enlarged view of a portion A of the stop valve 100 shown in

[0047] As shown in Figure 1 and Figure 2 , the stop valve 100 includes a main body portion 110, an upper housing 120, a lower housing 130, a conduction portion 140, a fastening bolt 150, a valve body portion 160, a diaphragm portion 170, a spring 180, and an electric field elimination portion 190.

[0048] The main body portion 110 is a member in which a fluid flow passage (inflow side flow passage 113, valve chamber 114, outflow side flow passage 115, which will be described later) that guides a fluid from the inflow port 111 toward the outflow port 112 is formed inside. The main body portion 110 is formed of a fluororesin material.

[0049] The fluid flow passage formed inside the main body portion 110 has the inflow side flow passage 113, the valve chamber 114, and the outflow side flow passage 115. The fluid that flows into the inflow side flow passage 113 is guided toward the valve chamber 114, and the fluid that is guided toward the valve chamber 114 is guided toward the outflow side flow passage 115. A valve hole 113a through which the valve body portion 160 approaches or separates along the axis X1 is formed at an end portion of the inflow side flow passage 113 on the valve chamber 114 side.

[0050] The upper case 120 is disposed above the main body portion 110 and accommodates the diaphragm portion 170 and the components of the de-electrification portion 190 in a space formed between the main body portion 110. The lower case 130 is disposed below the main body portion 110 and is disposed on the setting surface S.

[0051] As shown in FIG. 1, the main body portion 110, the upper case 120, and the lower case 130 are integrated by fastening the upper case 120 and the lower case 130 with the fastening bolts 150 in a state of sandwiching the main body portion 110. The upper case 120 and the lower case 130 are integrated, for example, by four fastening bolts 150 disposed at positions equidistant from the axis X1. Figure 1 The lead-through portion 140 is a metal member disposed in a state of being sandwiched between the main body portion 110 and the upper case 120 in a direction along the axis X1. The lead-through portion 140 is installed in a state of contacting the de-electrification portion 190. The lead-through portion 140 is connected to the ground cable 10 maintained at the ground potential and is maintained at the ground potential.

[0052] As shown in FIG. 1, the valve body portion 160 is a member formed in an axis along the axis X1 and approaches or separates from the valve hole 113a that guides fluid from the inflow-side flow passage 113 to the valve chamber 114. The valve body portion 160 is movable along the axis X1 by the approaching force generated by the pressure chamber 121 described later.

[0053] Figure 1 The stop valve 100 is switchable between a closed state in which the valve body portion 160 is brought into contact with the main body portion 110 to block the inflow of fluid from the valve hole 113a to the valve chamber 114 and an open state in which the valve body portion 160 is separated from the main body portion 110, as shown in FIG. 1. Figure 2 The valve chamber 114 is a space disposed with the valve body portion 160, communicates with the inflow-side flow passage 113 and the outflow-side flow passage 115, and is formed between the main body portion 110 and the lower surface of the diaphragm portion 170.

[0054] Figure 1 As shown in FIG. 1, 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 disposed in the valve chamber 114 and is formed in a ring shape around the axis X1 in a manner of separating the valve chamber 114 in which the valve body portion 160 is disposed and the 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 a ring shape around the axis X1. Figure 2 As shown in FIG. 1, 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 disposed in the valve chamber 114 and is formed in a ring shape around the axis X1 in a manner of separating the valve chamber 114 in which the valve body portion 160 is disposed and the 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 a ring shape around the axis X1.

[0055] Figure 2 As shown in FIG. 1, 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 disposed in the valve chamber 114 and is formed in a ring shape around the axis X1 in a manner of separating the valve chamber 114 in which the valve body portion 160 is disposed and the 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 a ring shape around the axis X1.

[0056] ​​​Diaphragm 170 is formed integrally with valve body 160 from a fluororesin material. Thin film 171 is formed in an annular shape around axis X1 and is thin-film with a thickness of 0.2 to 0.5 mm. Thin film 171 is flexible enough to deform as valve body 160 moves along axis X1.

[0057] The spring (metal component) 180 is a metal component (e.g., stainless steel) that generates a force along the axis X1 of the valve body 160 in a direction that separates the valve body 160 from the valve hole 113a. The lower end of the spring 180 is positioned in contact with the upper housing 120, while the upper end of the spring 180 is positioned in contact with the piston 185. The lower end of the piston 185 is connected to the upper end of the valve body 160. Therefore, the force generated by the spring 180 is transmitted to the upper end of the valve body 160 via the piston 185.

[0058] Static eliminator 190 is an annular component formed around axis X1 and positioned between main body 110 and base 172 of diaphragm 170 along axis X1. It is formed from a conductive fluororesin material containing a fluororesin material and a conductive material dispersed within the fluororesin material. It includes an exposed portion 191 that is exposed toward valve chamber 114 and forms a portion of the inner circumferential surface of valve chamber 114.

[0059] Figure 3 yes Figure 2 FIG. 1 is a partial enlarged view of the B portion of the stop valve 100. Figure 3 As shown, static eliminator 190 includes housing 192 that houses base 172 on the inner circumferential side in radial direction RD orthogonal to the direction along axis X1. Base 172 and static eliminator 190 are arranged with outer circumferential surface 172a of base 172 in contact with inner circumferential surface 192a of housing 192.

[0060] A first annular projection 172b is formed on the outer edge of base 172 in radial direction RD. The first annular projection 172b protrudes toward static eliminator 190 and is annular about axis X1. A first annular groove 193 is formed in a region of static eliminator 190 opposite first annular projection 172b.

[0061] The base 172 and static eliminator 190 are arranged with the first annular protrusion 172b inserted into the first annular groove 193. The contact between the first annular protrusion 172b and the first annular groove 193 forms a sealed area around the entire circumference of the axis X1. This sealed area reliably prevents fluid from leaking from between the static eliminator 190 and the diaphragm 170.

[0062] The static eliminating portion 190 includes a second annular protrusion 194 that projects toward the main body 110 and is annular about the axis X1. A second annular groove 116 that is annular about the axis X1 is formed in a region of the main body 110 that faces the second annular protrusion 194.

[0063] 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 contact between the second annular protrusion 194 and the second annular groove 116 forms a sealed area around the entire circumference of the axis X1. This sealed area reliably prevents fluid from leaking out from between the static eliminator 190 and the main body 110.

[0064] like Figure 3 As shown, 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 sealing area formed by the second annular protrusion 194 and the second annular groove 116.

[0065] 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 the area encompassed by the sealing region R2, where the first annular protrusion 172b and the first annular groove 193 are arranged along the axis X1. The length L1 of the predetermined region R1 along the axis X1 is shorter than the length L2 of the sealing region R2 along the axis X1. The length L1 is preferably set to, for example, 0.1 mm to 2.0 mm.

[0066] Figure 3 The stop valve 100 shown in the figure has a second annular protrusion 194 formed on the static elimination portion 190 and a second annular groove 116 formed on the main body 110, but other forms are also possible. Figure 4 The modified example shown. Figure 4 It is a partially enlarged view showing a modified example of the stop valve 100 .

[0067] exist Figure 4 In the illustrated stop valve 100, a second annular protrusion 117 is formed on the body 110, protruding toward the static eliminator 190 and annular about the axis X1. A second annular groove 195 is formed in an area of ​​the static eliminator 190 opposite the second annular protrusion 117, annular about the axis X1.

[0068] 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 contact between the second annular protrusion 117 and the second annular groove 195 forms a sealed area around the entire circumference of the axis X1. This sealed area reliably prevents fluid from leaking out from between the static eliminator 190 and the main body 110.

[0069] like Figure 4 As shown, 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 sealing area formed by the second annular protrusion 117 and the second annular groove 195.

[0070] The main body 110, upper housing 120, lower housing 130, valve body 160, and diaphragm 170 of the stop valve 100 of this embodiment are formed of a fluororesin material that does not contain a conductive material. Meanwhile, the static eliminating portion 190 of the stop valve 100 of this embodiment is formed of a fluororesin material that contains a conductive material.

[0071] Examples of the fluororesin material include PTFE (polytetrafluoroethylene), PCTFE (polychlorotrifluoroethylene), and PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer). As the fluororesin material, a powdered material (for example, PTFEG163 manufactured by Asahi Glass) can be used.

[0072] As the conductive material, for example, carbon nanotubes can be used. As the carbon nanotubes, for example, carbon nanotubes having the following properties are preferably used.

[0073] · Having a fiber length of 50 μm or more and 150 μm or less.

[0074] · Having a fiber diameter of 5 nm or more and 20 nm or less.

[0075] ·With 10mg / cm 3 Above and 70mg / cm 3 The following bulk density.

[0076] The G / D ratio is 0.7 or more and 2.0 or less.

[0077] Purity is 99.5% or more.

[0078] · Formed into multiple layers (for example, 4 to 12 layers).

[0079] The reason why the fiber length of the carbon nanotubes is set to 50 μm or more is to impart sufficient conductivity with a small amount when the carbon nanotubes are dispersed in the fluororesin material.

[0080] The G / D ratio is the ratio of the G-band peak to the D-band peak in the Raman spectrum of a carbon nanotube. The G-band originates from the graphite structure, while the D-band originates from defects. The G / D ratio represents the ratio of the purity of the crystal to the defect concentration of the carbon nanotube.

[0081] The inventors investigated the relationship between the amount of carbon nanotubes added to a fluororesin material (% by weight) and the volume resistivity (Ω·cm) of a conductive fluororesin material containing the fluororesin material and the carbon nanotubes dispersed therein, and found that Figure 5 The results shown. Figure 5 The results shown are the results of measuring the volume resistivity of the test pieces based on the "Electroconductive Plastics - 4-Probe Test Method" specified in JIS K7194.

[0082] As a test piece, a plurality of test pieces that are melt-kneaded by a mixer and then compression-molded by a compression molding machine are processed into test pieces of a size according to JIS K7194. The fluororesin material used to make the test piece is PTFE G163 manufactured by Asahi Glass. In addition, in the determination of volume resistivity, a resistivity meter using a 4-probe method based on JIS K7194 is used. The 4-probe method is a method in which 4 needle-shaped probes (electrodes) are brought into contact with the test piece and the resistance of the test piece is obtained based on the current flowing between the 2 probes on the outside and the potential difference generated between the 2 probes on the inside. The volume resistivity is calculated by averaging the measured values ​​obtained at multiple locations by multiple test pieces.

[0083] according to Figure 5 The results show that by setting the addition amount of carbon nanotubes in the range of 0.020 wt% to 0.030 wt%, the volume resistivity of the conductive fluororesin material becomes greater than 1.0×10 3 Ω·cm and less than 1.0×10 4 The volume resistivity value is in the range of Ω·cm. The volume resistivity value of the fluororesin material in which carbon nanotubes are not dispersed is (10 18 Ω·cm) is sufficiently low.

[0084] The inventors used a shutoff valve 100 in which the static elimination portion 190 was formed from a conductive fluororesin material containing 0.025% by weight of carbon nanotubes. While air at 50 kPa flowed through the inlet flow passage 113, the valve chamber 114, and the outlet flow passage 115, they measured the voltage generated in the valve chamber 114. The results showed that the voltage generated in the valve chamber 114 remained at approximately 0.2 kV.

[0085] On the other hand, the charged voltage generated in the valve chamber 114 was measured in a state where 50 kPa of air was circulated in the inflow-side flow passage 113, the valve chamber 114, and the outflow-side flow passage 115, in the case of a stop valve of a comparative example in which the electrification removing portion 190 was formed of a fluororesin material to which no carbon nanotube was added. As a result, the charged voltage generated in the valve chamber 114 was maintained at about 3.0 kV or more.

[0086] According to the above result, in the present embodiment, the electroconductive fluororesin material forming the electrification removing portion 190 contains the carbon nanotube at a ratio of 0.020% by weight or more and 0.030% by weight or less. In addition, the electrification removing portion 190 is connected to the ground cable 10 via the conductive portion 140. In addition, thereby, the volume resistivity of the electroconductive fluororesin material becomes in a range of more than 1.0 x 10 3 Ω·cm and less than 1.0 x 10 4 Ω·cm, it is possible to maintain the charged voltage generated in the valve chamber 114 at a low value of about 0.2 kV.

[0087] The function and effect of the stop valve 100 of the present embodiment described above will be described.

[0088] According to the stop valve 100 of the present embodiment, the electrification removing portion 190 formed of the electroconductive fluororesin material is arranged in a state of being sandwiched between the main body portion 110 in which the inflow-side flow passage 113, the valve chamber 114, and the outflow-side flow passage 115 are formed inside, and the base portion 172 of the diaphragm portion 170 which is joined to the outer peripheral surface of the valve body portion 160. The electrification removing portion 190 which is maintained at the ground potential via the conductive portion 140 has the exposed portion 191, thereby removing the positive charge generated in the fluid due to the friction of the diaphragm portion 170 with the fluid, and along therewith, the negative charge in the diaphragm portion 170 is removed. Therefore, it is possible to suppress the adverse situation that the film-shaped diaphragm portion 170 causes the fluid circulating in the valve chamber 114 to flow out from the diaphragm portion 170 due to insulation breakdown. In addition, compared with the case where the diaphragm portion 170 and the valve body portion 160 are formed of the electroconductive fluororesin material as a whole, it is possible to reduce the contact area of the electroconductive fluororesin material with the fluid, and prevent the contamination of the fluid due to the elution of metal ions from the electroconductive fluororesin material.

[0089] According to the stop valve 100 of the present embodiment, since it is arranged in a state that the outer peripheral surface 172a of the base portion 172 is in contact with the inner peripheral surface 192a of the accommodation portion 192, it is possible to reliably prevent the movement of the base portion 172 toward the outside in the radial direction RD and the change in the position of the base portion 172 in the radial direction RD.

[0090] According to the stop valve 100 of the present embodiment, the first annular protrusion portion 172b formed on the outer edge of the radial direction RD of the base portion 172 is arranged so as to be inserted into the first annular groove portion 193 formed in the de-electrification portion 190, and a seal region R2 is formed around the entire circumference of the axis X1. With this seal region R2, it is possible to reliably prevent fluid from flowing out between the base portion 172 and the de-electrification portion 190.

[0091] According to the stop valve 100 of the present embodiment, a prescribed region R1 included in the seal region R2 of the first annular protrusion portion 172b and the first annular groove portion 193 arranged in the direction along the axis X1 is exposed to the valve chamber 114 by the exposed portion 191 of the de-electrification portion 190. Since the exposed portion 191 is present in the vicinity of the diaphragm portion 170, it is possible to reliably de-electrify fluid that has become positively charged due to friction with the thin film portion 171 and the thin film portion 171.

[0092] According to the stop valve 100 of the present embodiment, by making the length L1 in the direction along the axis X1 of the prescribed region R1 shorter than the length L2 of the seal region R2, it is possible to reduce the area of the exposed portion 191 and prevent contamination of the fluid due to elution of metal ions from the electrically conductive fluororesin material.

[0093] According to the stop valve 100 of the present embodiment, the second annular protrusion portion 194 formed in the de-electrification portion 190 is arranged so as to be inserted into the second annular groove portion 116 formed in the main body portion 110, and a seal region is formed around the entire circumference of the axis X1. With this seal region, it is possible to reliably prevent fluid from flowing out between the de-electrification portion 190 and the main body portion 110.

[0094] According to the stop valve 100 of the present embodiment, load from the first annular protrusion portion 172b toward the first annular groove portion 193 is transmitted from the second annular protrusion portion 194 to the second annular groove portion 116, and thus it is possible to improve the sealability of the seal region formed by the second annular protrusion portion 194 and the second annular groove portion 116.

[0095] According to the stop valve 100 of the present embodiment, the second annular protrusion portion 117 formed in the main body portion 110 is arranged so as to be inserted into the second annular groove portion 195 formed in the de-electrification portion 190, and a seal region is formed around the entire circumference of the axis X1. With this seal region, it is possible to reliably prevent fluid from flowing out between the de-electrification portion 190 and the main body portion 110.

[0096] According to the stop valve 100 of the present embodiment, load from the first annular protrusion portion 172b toward the first annular groove portion 193 is transmitted from the second annular groove portion 195 to the second annular protrusion portion 117, and thus it is possible to improve the sealability of the seal region formed by the second annular protrusion portion 117 and the second annular groove portion 195.

[0097] [Second embodiment]

[0098] Next, a stop 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 is identical to the stop valve 100 according to the first embodiment except for the following special descriptions, and descriptions thereof will be omitted.

[0099] The conduction portion 140 included in the stop valve 100 of the first embodiment is a metal member disposed along the axis X1 and sandwiched between the main body 110 and the upper housing 120. In contrast, the conduction portion 140A included in the stop valve 100A of this embodiment is an electric wire having a conductor 141 and an insulator 142.

[0100] like Figure 6 As shown, the stop valve 100A of this embodiment has a conductive portion 140A that is in contact with the static eliminating portion 190 and is maintained at a ground potential. The conductive portion 140A is configured such that an insulator 142 is sandwiched between the main body 110 and the upper housing 120. Figure 7 As shown, the conductive portion 140A is an electric wire having a linear conductor 141 made of metal (eg, copper) maintained at ground potential and formed therein, and an insulator 142 made of an insulating material (eg, resin) covering the conductor 141 .

[0101] like Figure 8 As shown, the main body 110 is provided with a housing surface 110a annularly arranged around the axis X1 so as to contact the outer peripheral surface 190a of the static eliminating portion 190. Figure 7 As shown, a groove 110b extending along the axis X1 is formed on the housing surface 110a. The conductor 141 exposed at the front end of the conductive portion 140A is housed in the groove 110b so as to be electrically connected to the static eliminating portion 190.

[0102] like Figure 8 As shown, the conductor 141 exposed at the tip of the via 140A is fixed to the groove 110b by an adhesive 143 containing a conductive material (e.g., silver conductive particles). With the tip of the via 140A, from which the insulator 142 has been removed and the conductor 141 is exposed, housed in the groove 110b, an operator injects the adhesive 143 into the groove 110b.

[0103] like Figure 7 and Figure 8As shown, a receiving groove 110c extending along the radial direction RD is formed on the upper surface of the main body portion 110. The width Wl of the receiving groove 110c is formed to be narrower than the width W2 of the conductive portion 140A in the natural state. Therefore, by pressing the conductive portion 140A into the receiving groove 110c, it is possible to maintain the state in which the conductive portion 140A is received in the receiving groove 110c.

[0104] According to the stop valve 100A of the present embodiment, the electric wire having the conductor 141 and the insulator 142 covering the conductor 141 is used as the conductive portion 140A, and the conductor 141 exposed at the front end of the conductive portion 140A is received in the groove portion 110b formed on the receiving surface 110a of the main body portion 110, whereby it is possible to comparatively simply maintain the de-electrifying portion 190 at the ground potential.

[0105] In addition, according to the stop valve 100A of the present embodiment, in the state in which the conductor 141 exposed at the front end of the conductive portion 140A is received in the groove portion 110b, the adhesive 143 containing a conductive material is injected into the groove portion 110b and is cured, whereby it is possible to maintain the state in which the conductor 141 is electrically connected to the de-electrifying portion 190 and to reliably fix the conductor 141 to the groove portion 110b.

[0106] 〔Other Embodiments〕

[0107] In the above description, the stop valve 100 is described as a fluid device, but it can be another fluid device. For example, it can be another fluid device such as a flow rate adjusting device that adjusts the flow rate of a fluid by adjusting the amount of insertion of a needle valve into a valve hole.

Claims

1. A fluid device, comprising: a valve body portion formed in a shaft shape extending along an axis and movable along the axis; a main body portion internally formed with a valve hole approaching or separating from the valve body portion and a fluid flow passage through which a fluid flows; a diaphragm portion having a thin film portion joined to an outer peripheral surface of the valve body portion and formed in a ring shape around the axis in a manner of isolating a valve chamber in which the valve body portion is disposed and an adjacent space adjacent to the valve chamber, and a base portion joined to an outer peripheral side of the thin film portion and formed in a ring shape around the axis; a de-electrification portion formed in a ring shape around the axis and disposed in a state of being sandwiched between the main body portion and the base portion in a direction along the axis; and a conduction portion in contact with the de-electrification portion and maintained at a ground potential, the de-electrification portion is formed of an electroconductive fluororesin material containing a fluororesin material and an electroconductive material dispersed in the fluororesin material, and has an exposed portion exposed to the valve chamber.

2. The fluid device according to claim 1, the de-electrification portion has a receiving portion receiving the base portion on an inner peripheral side in a radial direction orthogonal to the direction along the axis, the base portion and the de-electrification portion are disposed in a state that an outer peripheral surface of the base portion is in contact with an inner peripheral surface of the receiving portion.

3. The fluid device according to claim 2, a first annular protrusion portion protruding toward the de-electrification portion and formed in a ring shape around the axis is formed on an outer edge in the radial direction of the base portion, a first annular groove portion formed in a ring shape around the axis is formed in a region of the de-electrification portion opposite to the first annular protrusion portion, the base portion and the de-electrification portion are disposed in a state that the first annular protrusion portion is inserted into the first annular groove portion.

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

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

6. The fluid device according to any one of claims 3 to 5, a second annular protrusion portion protruding toward the main body portion and formed in a ring shape around the axis is formed in the de-electrification portion, a second annular groove portion formed in a ring shape around the axis is formed in a region of the main body portion opposite to the second annular protrusion portion, the de-electrification portion and the main body portion are disposed in a state that the second annular protrusion portion is inserted into the second annular groove portion.

7. The fluid device according to claim 6, the first annular protrusion portion, the first annular groove portion, the second annular protrusion portion, and the second annular groove portion are disposed at the same position in the radial direction. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 8. The fluid apparatus according to any one of claims 3 to 5, wherein a second annular protruding portion protruding toward the destaticizing portion and formed annularly around the axis is formed in the main body portion, a second annular groove portion formed annularly around the axis is formed in a region of the destaticizing portion opposite the second annular protruding portion, the main body portion and the destaticizing portion are arranged with the second annular protruding portion inserted into the second annular groove portion.

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

10. The fluid apparatus according to any one of claims 1 to 5, wherein the conducting portion is an electric wire having a conductor made of metal maintained at a ground potential and formed in a linear shape, and an insulator covering the conductor, a receiving surface arranged annularly around the axis in contact with an outer peripheral surface of the destaticizing portion is formed in the main body portion, a groove portion extending along the axis is formed in the receiving surface, the conductor exposed at a front end of the conducting portion is received in the groove portion in a manner of conducting with the destaticizing portion.

11. The fluid apparatus according to claim 10, wherein the conductor exposed at the front end of the conducting portion is fixed to the groove portion by an adhesive containing an electrically conductive material.

Images