JP2003322127A - Fluid coupling - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fluid coupling capable of improving sealing performance by using a publicly known or existing screw means. <P>SOLUTION: This fluid coupling comprises first and second block-shaped joint members 3a, 9, a seal member interposed between a butting end surfaces of the joint members, and a screw means uniting the joint members. The screw means is composed of a bolt 15 inserted in a through hole formed in the joint member 3a, and a screw 14 provided on the joint member 9 and into which the bolt 15 is screwed in. A composite plating film wherein fluorine-containing compound fine particles are generally uniformly eutectoid is deposited on at least either of the bolt 15 and the screw 14. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluid coupling, and more particularly to a fluid coupling in which coupling members are connected by screw means and high sealing performance is required.

[0002]

2. Description of the Related Art Conventionally, as a fluid coupling, one which secures a sealing property by connecting tubular coupling members with screw means and deforming a sealing member interposed between the abutting end faces of both coupling members is often used. Are known. In addition, in a fluid control device for semiconductor manufacturing, instead of the tubular joint member, a block joint member having fluid passages communicating with each other is used.

[0003]

According to the above-mentioned conventional fluid coupling, not only the sealability is ensured but also the installation space needs to be reduced, so that the sealability is improved without increasing the installation space. The challenge is to let them do it.

An object of the present invention is to focus on screw means for connecting joint members to each other, and to provide a fluid joint capable of improving sealing performance by utilizing a known or existing screw means. Especially.

[0005]

A fluid coupling according to the present invention is provided between first and second coupling members having fluid passages communicating with each other and between the abutting end surfaces of the coupling members. A sealing member, and a fluid coupling provided with screw means for connecting both coupling members,
It is characterized in that the screw means is provided with a composite plating film in which fine particles of a fluorine-containing compound are co-deposited on a metal substantially uniformly.

To form a composite plating film, for example,
If necessary, the fluorine-containing compound fine particles are substantially evenly dispersed in the metal plating solution by using the surface activity of a fluorine-based surfactant or the like, and screw means (bolt, nut, female screw or It is performed by immersing the joint member itself in which the male screw is integrally formed) and electroplating or electroless plating.

Before forming the composite plating film, the base metal may be subjected to nickel plating treatment, cobalt plating treatment or the like. Further, after forming the composite plating film, additional surface treatment such as plating treatment may be further performed. Although the heat treatment at the time of forming the composite plating film is unnecessary, it is not limited to the heat treatment.

Suitable metals include silver, gold, platinum, palladium, rhodium, indium, nickel, iron, copper and aluminum.

The fluorine-containing compound is preferably a polymer compound having a perfluoroalkyl group or a polyfluoroalkyl group in which all or part of the hydrogen portion of a hydrocarbon group is replaced with fluorine, and among them, polytetrafluoroethylene It is preferable to use at least one of (PTFE), polychlorotrifluoroethylene, polyvinylidene fluoride, and tetrafluoroethylene-hexafluoropropylene copolymer.

According to the fluid coupling of the present invention, the metal component of the composite plating film prevents the screw means from being damaged (such as galling), and the fluorine-containing compound in the composite plating film reduces friction. It Due to the reduced friction, a higher thrust can be obtained for the same tightening torque when tightening the screw means, which results in
The sealing property can be improved. In order to reduce friction, it has been considered to coat silver-plated bolts with polytetrafluoroethylene.
It is inferior to the present invention in that it causes a problem of fluid contamination due to partial peeling of the coating layer.

The structure of the fluid coupling is not particularly limited. For example, each coupling member has a block shape, and the screw means has a bolt inserted into a through hole provided in one coupling member and the other. The plating may be provided on at least one of the bolt and the female thread portion, which is provided on the joint member and into which the bolt is screwed, and the plating may be provided on at least one of the bolt and the female thread portion (ease of manufacture and easy replacement at the time of use). From the point of view, it is preferable to provide the bolt on the bolt.) Further, each joint member is tubular, one joint member is provided with a flange portion, and the screw means is a male screw portion provided on the other joint member, and a top portion. The cap nut is fitted to one joint member so that the inner surface of the wall is in contact with the flange portion and screwed to the male screw portion of the other joint member, and the plating is performed with at least the cap nut and the male screw portion. On the other hand sometimes provided in (by providing in terms of production of ease and replacement of ease of use in the cap nut it is preferred.). The former one is
It is preferably used in a fluid control device called an integrated device configured without using tubes, and the latter one is preferably used when connecting tubes in the middle of piping. In the latter case, the male screw portion may be integrally provided on the outer circumference of one joint member, or may be a member separate from the joint member.

As the seal member, a metal gasket,
Various materials such as a metal C ring and a metal O ring can be used.

The bolt and cap nut of the screw means are preferably made of stainless steel (SUS304, SUS316, etc.), and the joint member is also made of stainless steel (SUS304, SU).
S316) is preferred. The seal member is made of stainless steel, nickel alloy, etc., and has an annular shape (perforated disc shape).
A gasket formed in the above is preferable.

As the metal and fluorine-containing compound, those mentioned above can be appropriately used, but the eutectoid plating of silver-polytetrafluoroethylene has a balance between sealing property, easiness of production and cost. Excellent from the point.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

1 and 2 show an example of a fluid control system in which the fluid coupling of the present invention is used. This fluid control device is used in a semiconductor manufacturing apparatus or the like, and includes a mass flow controller (1) and a plurality of fluid control devices (2) (3) (4) (5) (6) ( 7)
The line having (8) is arranged in parallel. In the illustrated line, the mass flow controller (1)
2 port on-off valve (2), 3 port on-off valve (3),
A pressure gauge (4), a pressure regulator (5), a filter (6), a manual valve (7), etc. are provided, and a 2-port on-off valve (8) is provided on the outlet side.

On the inlet side and the outlet side of the mass flow controller (1), a rectangular parallelepiped overhanging portion (1) having an inverted L-shaped passage is provided.
a) (1b) is provided and other fluid control equipment (2) (3) (4)
Square flanges (2a) (3a) (4a) (5a) (6a) (7a) (8a) with required fluid passages are provided at the lower end of (5) (6) (7) (8). Has been. Overhangs (1a) (1b) of the mass flow controller (1)
Underside and flange parts (2a) (3a) (4a) (5a) (6a) (7a) (2) (3) (4) (5) (6) (7) (8) The lower surface of 8a) is made flush.

The mass flow controller (1) and the fluid control device (2) (3) (4) (5) (6) (7) (8) are adjacent to each other in the V-shaped passage ( They are connected by a block-shaped joint (9) with 9a). The V-shaped passage (9a) of the block-shaped joint (9) has two upward openings (9b) arranged at a predetermined interval in the line direction.
Two block-shaped joints below the 3-port on-off valve (3)
Between (9) is a block-shaped joint connected to the next line.
(10) is provided. This block joint (10) has 1
It has three upward openings (10a). The manual valve (7) and the outlet-side two-port on-off valve (8) are provided with a joint (11) for connection with an external pipe having an upward opening (11a).
Upward opening (9b) (10a) (1) of each block joint (9) (10) (11)
1a) is a bulge portion (1a) (1b) of the mass flow controller (1) and each fluid control device (2) (3) via a seal portion described later.
(4) (5) (6) (7) (8) Flange (2a) (3a) (4a) (5a) (6a) (7
a) It is butted against the downward opening provided in (8a).

The fluid control device is assembled by attaching lines similar to those shown in FIGS. 1 and 2 in parallel to the substrate. For the fittings (9) (10) (11), hexagon socket head cap screws (male thread members) that are screwed into the screw holes of the board.
Bolt insertion hole (13) through which (12) is inserted, and mass flow controller (1) and fluid control device (2) (3) (4) (5) (6) (7) (8)
And a female thread portion (14) for attaching the joint to these joints (9), (10) and (11). Coupling for connection with adjacent line
The length in the line direction of the joint (11) for connection with (10) and the external pipe is half the length in the line direction of the joint (9) having the V-shaped passage (9a). In the joint (9) having the V-shaped passage (9a), the bolt insertion hole (13) is orthogonal to the line with the center position between the two upward openings (9b) interposed therebetween.
They are provided so that they are arranged side by side, or one of the two is omitted, and the female screw portion (14) is arranged so as to be orthogonal to the line with each opening (9b) interposed therebetween. They are provided in pairs, that is, at the four corners. Further, in the joint (10) for connecting with the adjacent line and the joint (11) for connecting with the external pipe, the bolt insertion hole (13) is orthogonal to the line so as to sandwich the upward opening (10a) (11a). And two of them are arranged side by side or one of the two is omitted, and the female thread portion (14) is orthogonal to the line with the openings (10a) and (11a) interposed therebetween. One pair is provided so as to line up. In addition, the overhanging parts (1a) (1b) of the mass flow controller (1) and the flange parts of each fluid control device (2) (3) (4) (5) (6) (7) (8)
(2a) (3a) (4a) (5a) (6a) (7a) (8a) has fittings (9) (10) (11)
A bolt insertion hole (16) into which a hexagon socket head cap screw (male thread member) (15) screwed into the female thread portion (14) is inserted is provided.

When assembling the fluid control device, first,
Attach the joints (9), (10) and (11) that are lower members to the board with hexagon socket head cap bolts (12) from above, and attach these joints (9)
A hexagonal hole from above from the mass flow controller (1) and fluid control device (2) (3) (4) (5) (6) (7) (8) Install with bolts (13). Mass flow controller (1) and fluid control equipment (2) (3) (4)
If any of (5), (6), (7), or (8) needs to be repaired or replaced, remove the hexagon socket head cap screw (15) to which the target device is attached and remove it from the target. Can be removed upwards.

FIGS. 3 (a) and 3 (b) show a fluid coupling used in the above fluid control apparatus, and FIG.
And the flange portion (2) of the 2-port on-off valve (2) shown in FIG.
a) An enlarged cross-sectional view of the flange portion (3a) of the 3-port on-off valve (3) and the abutting portion of the block-shaped joint (9) with the V-shaped passage (9a), and (b) is a 3-port on-off valve. FIG. 7 is a cross-sectional view further enlarging a butt portion of a flange portion (3a) (hereinafter referred to as a first joint member) of (3) and a block-shaped joint (9) (hereinafter referred to as a second joint member).

First joint member (3a) and second joint member (9)
The butted end faces of the recesses (69) (7)
0) is provided, the bottom of each recess (69) (70) is provided with a cylindrical protrusion (71) (72) having a gasket pressing annular protrusion (71a) (72a) at the tip. ing. An annular gasket (73) held by a retainer (74) between both members (3a) (9).
Is intervened. The retainer (74) is attached to the outer peripheral portion of the cylindrical protrusion (72) of the block-shaped joint (9). The flange portion (2a) of the 2-port on-off valve (2) and the abutting portion of the block-shaped joint (9) are also constructed in exactly the same manner.

The fluid passages (75) (76) of the first and second joint members (3a) (9) are formed by the inner peripheral surfaces of the cylindrical protrusions (71) (72) and are orthogonal to the abutting end faces. Short opening passage (7
5a) and (76a), and main passages (75b) and (76b) connected to this in a slanting manner.

The diameter of each opening passage (75a) (76a) is equal to the inner diameter of each gasket pressing annular protrusion (71a) (72a), and the inner diameter of the gasket (73) is equal to the opening passage (75a) (76a). ) Is smaller than the diameter. This passage (75b) (76b) is
It is perforated to the maximum diameter corresponding to the diameter of 5a) (76a).

According to this fluid coupling, the first joint member (3a) and the second joint member (9) are joined by tightening the bolt (15) shown by reference numeral (15) in FIGS. 1 and 2. At the same time, the gasket (73) interposed between the abutting end faces of both members (3a) (9) is pressed and deformed by the gasket pressing annular protrusions (71a) (72a), and a fluid-tight connection is achieved. .

A bolt (1) for connecting the joint members (3a) (9) to each other
5) is provided with a composite plating film (not shown) in which silver containing fluorine-containing compound (PTFE) fine particles are substantially uniformly codeposited. This is carried out by electroless plating using an electroless silver plating bath in which PTFE fine particles are dispersed with a surfactant.

FIG. 4 is a thrust measuring device (20) for investigating the characteristics of the bolt (15) used in the fluid coupling of the present invention.
Is shown. This device (20) includes a load cell mounting table (21) having a concave portion on the upper surface, a load cell (22) mounted on the bottom surface of the concave portion of the mounting table (21), and two vertical cells provided at a predetermined interval. Since it has a female screw part (23a) and is connected to the upper surface of the mounting table (21) with a bolt (24), it is located in the center of the screw base (23) and the two female screw parts (23a) of the female screw base (23). A load transmission shaft that is inserted into a vertical through hole provided, the lower end is received by the load cell (22), and the upper end projects slightly above the upper surface of the female screw base (23).
(25) and a plate (26) mounted on the upper end of the load transmission shaft (25) and provided with an inspection bolt insertion hole (26a) corresponding to each vertical female screw portion (23a). This measuring device (20)
According to the inspection, the underside of the head of the bolt (15) is the plate (26)
When the bolt (15) is screwed into the female thread (23a) while touching the upper surface, the thrust of this bolt (15) is applied to the plate (2
It is transmitted to the load cell (22) via 6) and the shaft (25), and the thrust of the bolt (15) is measured together with the value of the tightening torque.

FIG. 5 shows the tightening torque and the thrust of the bolt (15) measured by the thrust measuring device (20). In FIG. No. 1 is the value of the bolt with silver-PTFE composite plating film (M5 × L15), No. 2 is a bolt with different length silver-PTFE composite plating film (M5 x L
18), No. 3 and No. 4 shows a conventional bolt (silver-plated) used in the fluid control device targeted by the fluid coupling of the present invention. According to the measurement result, the conventional bolts (No. 3 and No. 4) have a tightening torque of 50 kgf · cm.
When the tightening torque is 50 kgf · cm, the thrust of the bolt (No. 1 and No. 2) of the present invention is about 900 kgf.
It is 1000 kgf. From the viewpoint of ensuring the sealing performance of the fluid coupling, the thrust is preferably 800 kgf or more, and the bolt with silver-PTFE composite plating film (1
It can be seen that by using 5), a fluid coupling with excellent sealing properties can be obtained.

FIG. 6 shows the results of elemental analysis by EPMA (X-ray microanalyzer) on the surface of the bolt with the silver-PTFE composite plating film. This figure is an excerpt of data from two detector tubes out of a plurality of detector tubes. From these, it can be seen that the surface of the bolt contains fluorine with an atomic number of 9 and an atomic weight of about 19. It is confirmed. Although not shown, when observing the electron micrograph, fluorine is shown as a black dot in both the secondary electron image and the backscattered electron image, which also confirms that fluorine is present. It was

In the above embodiment, the case where the bolt (15) is provided with the composite plating film has been described. However, instead of this, the female threads of the joint members (3a) (9) are provided with the composite plating film. Alternatively, a composite plating film may be provided on both the bolt (15) and the female thread portion of the joint member (3a) (9). Further, in the fluid coupling, various screw means different from the above are used, and even in that case, the above effect can be obtained by providing the screw means with the composite plating film.

FIG. 7 shows an example of a fluid coupling having different screw means. In the figure, a fluid coupling (40) includes tubular first and second coupling members (41) and (42) having fluid passages (41b) and (42b) communicating with each other, and both coupling members (41 ) A gasket (43) interposed between the butted end faces of (42),
And screw means for connecting both joint members (41, 42).

On the abutting end faces of the first and second joint members (41) (42), annular protrusions (41a) (42) for pressing the gasket are provided.
a) is provided, and a flange portion (42c) is provided near the end of the second joint member (42).

The screw means is such that the male screw portion (46) provided on the first joint member (41) and the second inner wall of the top wall are in contact with the flange portion (42c) via the thrust ring (45). Joint member (4
2) and a cap nut (44) fitted to the male screw part (46) of the first joint member (41).

The cap nut (44) is provided with a silver-PTFE composite plating film.

In this fluid coupling (40), the first coupling member (4
By tightening the cap nut (44) screwed to 1), the gasket (43) is deformed and an appropriate sealing force is obtained. At this time, since the cap nut (44) is provided with the silver-PTFE composite plating film, a large thrust can be obtained with respect to a predetermined tightening torque.
Compared to the case where a cap nut without a PTFE composite plating film is used, the sealability can be improved without changing the screw diameter or material of the cap nut.

[Brief description of drawings]

FIG. 1 is a perspective view showing a vertical cross section of a fluid control device as an example in which a fluid coupling according to the present invention is used.

FIG. 2 is an exploded perspective view of the device.

FIG. 3 is a partially enlarged vertical sectional view showing an embodiment of the fluid coupling according to the present invention.

FIG. 4 is a cross-sectional view showing a thrust measuring device for investigating the characteristics of a bolt used in the fluid coupling of the present invention.

FIG. 5 is a graph showing a tightening torque-thrust force relationship measured by the thrust force measuring device, showing measured values for a bolt used in the fluid coupling of the present invention and a conventional bolt.

FIG. 6 is a chart showing EPMA elemental analysis results of the surface of a bolt used in the fluid coupling of the present invention.

FIG. 7 is a partially enlarged vertical sectional view showing another embodiment of the fluid coupling according to the present invention.

[Explanation of symbols]

(3a) Flange part of 3-port on-off valve (1st joint member) (9) Block-shaped joint (2nd joint member) (9a) Fluid passage (14) Female thread (15) Bolt (40) Fluid joint (41 ) First joint member (41b) Fluid passage (42) Second joint member (42b) Fluid passage (43) Gasket (44) Cap nut (46) Male thread (73) Gasket (75) Fluid passage

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Michio Yamaji             Stock market association 2-3-2, Nishibori, Nishi-ku, Osaka             Inside Fujikin (72) Inventor Akihiro Morimoto             Stock market association 2-3-2, Nishibori, Nishi-ku, Osaka             Inside Fujikin (72) Inventor Tomohiro Nakata             Stock market association 2-3-2, Nishibori, Nishi-ku, Osaka             Inside Fujikin (72) Inventor Tsutomu Shinohara             Stock market association 2-3-2, Nishibori, Nishi-ku, Osaka             Inside Fujikin (72) Inventor Akihiro Yukawa             2-7-23, Kurono Nishi, Joto-ku, Osaka             Company Protonics Institute F-term (reference) 3J040 BA03 EA18 FA01 HA15

Claims (5)

[Claims] 1. A first joint member and a second joint member having fluid passages communicating with each other, a seal member interposed between abutting end faces of both joint members, and screw means for connecting both joint members. A fluid coupling provided with the screw means, wherein the screw means is provided with a composite plating film in which metal-containing fine particles of a fluorine-containing compound are substantially uniformly codeposited. 2. Each joint member is block-shaped, and the screw means includes a bolt inserted into a through hole provided in one joint member, and a female screw portion provided in the other joint member and into which the bolt is screwed. The fluid coupling according to claim 1, wherein the plating is provided on at least one of the bolt and the female thread portion. 3. Each joint member is tubular, one joint member is provided with a flange portion, and the screw means is such that the male thread portion provided on the other joint member and the inner surface of the top wall are in contact with the flange portion. A cap nut that is fitted to one joint member and is screwed to the external thread of the other joint member,
The fluid coupling according to claim 1, wherein the plating is provided on at least one of the cap nut and the male screw portion. 4. The fluid coupling according to claim 1, wherein the metal is silver. 5. The fluid coupling of claim 4, wherein the fluorine-containing compound is polytetrafluoroethylene.