JPH0260915B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cap nut tightening fluid coupling which has an unprecedentedly high degree of airtightness and also prevents the generation of particles.

In recent years, with the increasing speed of technological innovation, super LSI
As seen in ultra-super LSIs, there is a growing need to manufacture dramatically large-scale integrated circuits.
Manufacturing such large-scale integrated circuits requires the use of ultra-toxic gaseous fluids such as the semiconductor compound gallium arsenide and the formation of highly pure coatings under ultra-high vacuum. Semiconductor manufacturing equipment is inevitably required to have a high degree of airtightness.

However, in order to connect the flow path forming elements of such a device, it is impossible to weld all of them, and the device cannot be completed without a fluid coupling that is mechanically connected and has excellent airtightness. I can't do that. The fittings used for this purpose are mainly made in foreign countries because of their high reliability, and there are various types.
A typical example is the one shown in Figure 6.
Two sleeves 1 and 2 are connected via a gasket 3, and a nut 5 fitted into the other sleeve 2 is connected to a gland 4 having a threaded portion formed on the outer periphery of the sleeve 1. An example of this is a fluid coupling that is achieved by screwing together the two. However, this type of cap nut tightening is often used especially for small diameter pipes because it is simple and does not take up much space. Rotational torque is applied to the sleeve 2 due to friction, which causes the piping welded to the sleeve 2 to twist, and the rotation of the sleeve scratches the gasket surface, which can cause fluid leaks. It was hot. On the other hand, as shown in Fig. 3, a coil spring 1 is used as a gasket, which is made by connecting both ends of a relatively thin helical coil spring into a circular shape.
9 held by a metal tube 20 so that the outer center is open has been developed. Since this gasket has advantages such as being able to be used under low tightening force, the inventor of the present invention came up with the idea of using this gasket in the above-mentioned joint, and obtained very good results. However, when the lever gasket is tightened, the repulsive force of the coil spring damages the surface (sealing surface) where the metal tube of the gasket contacts the body and sleeve through the gasket, resulting in a high degree of airtightness. In addition, there was a problem in that fine linear scratches were formed on the gasket, making it impossible to use the expensive gasket repeatedly. In addition, when the cap nut is tightened, the gasket and the sealing surface rub against each other, generating particles, which are mixed into the reaction gas and carried onto the wafer together with the reaction gas, damaging the wafer. also had a fatal flaw.

The present inventor has focused on this point and, as a result of intensive research, has succeeded in developing a cap nut tightening fluid joint that can eliminate the above-mentioned drawbacks and exhibits outstanding airtightness, and has arrived at the present invention.

That is, the present invention consists of a body provided with a threaded portion on the outer periphery of one end of the tubular body, and a short annular portion provided on the outer periphery of the tip that abuts and communicates with a through hole on the threaded portion side of the body via a gasket. In a fluid coupling consisting of a sleeve and a cap nut that is fitted into the sleeve and threadedly engaged with a threaded portion of the body to firmly tighten the body and the sleeve, the tube-side surface of the sleeve and the bag A rotating means is provided on the contact surface with the nut,
The gasket is characterized in that a ring-shaped coil spring is held by a metal tube having a C-shaped cross section, and a roll burnishing surface is formed on the surface of the body and sleeve that abut through the gasket. do.

Further, the present invention comprises a body provided with a threaded portion on the outer periphery of one end of the tubular body, and a short annular portion provided on the outer periphery of the tip that contacts and communicates with a through hole on the threaded portion side of the body via a gasket. A fluid coupling comprising a sleeve and a cap nut that is fitted into the sleeve and screwed into a threaded portion of the body to firmly tighten the body and the sleeve, wherein the pipe side surface of the sleeve and the cap nut are connected to each other. A rotating means is provided on the contact surface of the
The contact surfaces of the body and the sleeve have a fitting recess and a fitting protrusion, respectively, and the end face of the fitting recess abuts the step of the fitting protrusion so that the gasket is not compressed by more than an effective elastic compression amount. The gasket is formed by holding a ring-shaped coil spring in a metal tube having a C-shaped cross section, and a roll burnishing surface is formed on the surfaces of the body and the sleeve that abut through the gasket. It is characterized by

In short, the present invention consists of two inventions, the first invention is that a roll burnishing surface is formed on the surface of the body and the sleeve that contact each other via a gasket,
A gasket consisting of a coil spring held by a metal tube is used as a gasket, and a rotating means is provided between the cap nut and the sleeve that can rotate only the cap nut without rotating the sleeve when tightening the cap nut. By providing this, it is possible to prevent the gasket and the sealing surface from rubbing against each other, thereby preventing the generation of particles and damage to the gasket, thereby maintaining a high degree of airtightness.

In addition, the second invention of the present application further allows the fitting concave portion and the fitting convex portion to fit together to prevent lateral wobbling and achieve natural perfect centering, thereby ideally connecting the body, sleeve, and gasket. The flatness of the gasket is thereby maintained and the risk of fluid leakage is further reduced.

Although roll burnishing itself is a well-known method, conventionally it has not been known at all to perform roll burnishing on the surfaces of the body and sleeve that come into contact with each other through a gasket. Currently, there is no known or commercially available machine that can perform roll burnishing on such surfaces. That is, in the case of a conventional gasket, there is no possibility that scratches would be formed on the surface where the body contacts the sleeve via the gasket due to the repulsive force of the spring.

The reason for the effect of the present invention is that by providing a rotating means, the generation of particles is prevented and the gasket is prevented from being overtightened, and the surface hardness is improved by the roll burnishing treatment. It is thought that this is because the gasket is less likely to be scratched, and as a result, a high degree of airtightness can be maintained, and fine linear scratches that cause airtightness deterioration are less likely to be formed on the gasket. Further, since the surface is made smooth by the roll burnishing treatment, the generation of particles is also prevented from this point of view. That is, if the roll burnishing treatment is not performed, fine irregularities will exist on the sealing surface, and particles contained in these irregularities will be mixed into the reaction gas.

"Example" Next, an example of the present invention will be described based on the drawings.

In FIG. 1, 11 is a body, 12 is a sleeve, and 13 is a cap nut, and the cap nut 13 is fitted into the sleeve 12.

The body 11 has a through hole at its center, and a threaded portion 14 is provided on the outer periphery of one end, and a protrusion 25 having a polygonal outer shape is provided on the outer periphery in connection with the threaded portion.
It has By screwing the cap nut 13 into the threaded portion 14, the sleeve 12 is tightened to the body 11 via the gasket 15.

The sleeve 12 has a through hole in its center, and a short annular portion 16 is provided on the outer periphery of its tip, and the surface of the short annular portion that is pressed into contact with the cap nut has a hole as shown in FIG. A ring-shaped groove 18 is provided in which a number of small balls 17 are fitted, which act as bearings.

In this way, in the present invention, the sleeve 12
Since a rotating means is provided between the cap nut 13 and the cap nut 13, even if rotational torque is applied to the sleeve 12 when screwing the cap nut 13 with the threaded portion 14 of the body, the cap nut 13 and the sleeve 12 will not rotate. is idling,
Since no force exceeding a certain level is applied to the sleeve 12, the gasket and the sealing surface do not rub against each other, thereby preventing the generation of particles and effectively preventing damage to the gasket.

FIG. 4 shows another embodiment of the rotating means of the present invention, which includes an inverted dish-shaped ring 28 having an opening in the center that fits into a tube 29, and a tube in the short annular portion 16 of the sleeve. An example is shown in which a small ball 17 is supported between the side surfaces. In this case, the tube 29 of the sleeve may be provided with a protrusion or groove for locking the ring 28.

Another embodiment of the invention, shown in FIG.
An example is shown in which 8 has a U-shaped cross section and a small ball 17 is held between this U-shaped portion.

Such a rotating means is not limited to the means using a small ball as described in the above embodiment, but other known means such as fitting a bush into the inner surface of a cap nut can be used as long as airtightness is maintained. It may also depend on rotation means.

The pipe end of the sleeve and the pipe end of the body are connected to a pipe by welding, thereby communicating the fluid passage between 26 and 27.

The gasket 15 used in the above embodiment is the third
As shown in the figure, a coil spring 19 is formed by connecting both ends of a relatively thin helical coil spring into a circular shape.
is held by a metal tube 20 so that the center of the outside is open. As the material of the coil spring, for example, stainless steel or Inconel material is preferably used, and as the material of the metal tube, aluminum, nickel, copper, monel, etc. are suitably used.

In order to allow the fluid coupling having the above-mentioned structure to exhibit its functions more fully, in the above-mentioned embodiment, an annular recess 2 is provided on the end surface of the body 11 on the screw 14 side.
1, and a protrusion 22 that fits into the recess 21 is provided on the surface of the sleeve 12 that contacts the gasket 15.

The gasket 15 is fitted into the recess 21 and pressed against the protrusion 22. The depth of the concave portion 21 and the height of the convex portion 22 are set so that the stepped portion 23 of the convex portion 22 rests on the end surface 24 of the body when the gasket is pressed to an effective elastic compression amount.

Conventional foreign-made fluid couplings indicate the effective compression amount of the gasket by the number of rotations at which the nut is tightened, but this number of rotations varies depending on the setting position of the gasket, the material, etc., and may vary in actual work. There are cases where it is not constant. For this reason, too much concern about leak tightness leads to overtightening, which results in the problem of damage or breakage of the gasket. If the gasket is damaged in this manner, even if the damage is slight, the flatness of the contact portion will be impaired and the airtightness will deteriorate. In the above embodiment, however, the stepped portion of the convex portion prevents the gasket from being compressed beyond the effective compression amount, so the drawback of the conventional gasket that the gasket is easily damaged is eliminated. At the same time, it prevents lateral wobbling and naturally perfect centering, allowing the body, sleeve, and gasket to ideally connect, thereby maintaining the flatness of the gasket and reducing the risk of fluid leakage. drastically reduce sexuality.

Roll burnishing process involves rotating rotating rollers.
This can be done by applying the contact surfaces of the gaskets of the body and sleeve, respectively. For example, if the sealing surface of the fluid coupling in the above embodiment is turned with a roughness of 3.2S and subjected to roll burnishing, 1~
A mirror surface with a roughness of 1.05 to 0.7S can be easily obtained with a processing time of 2 seconds. This burnishing treatment improves the surface hardness (in the case of stainless steel, the hardness of the base material
180HB hardness becomes 300HB or higher), which makes it difficult for scratches to form on the sealing surface of the gasket, and also prevents particles from forming because the surface is smooth.

``Effects'' As described above, the fluid coupling of the present invention uses a special gasket, uses a rotating means to prevent damage to the gasket and the generation of particles, and has roll burnishing applied to the sealing surface.
Scratches are less likely to be formed on the sealing surface, resulting in a high degree of airtightness, and fine linear scratches are also less likely to be formed on the gasket. Can be used repeatedly many times. Therefore, the fluid coupling of the present invention has excellent airtightness, and even an unskilled person can easily obtain a fluid coupling with a high airtightness with a helium leak rate of 10 ^-10 atm.cc/sec.
A fluid coupling having such a high level of excellent airtightness has never existed before, and is provided for the first time by the present invention. Furthermore, the fluid coupling of the present invention not only has excellent airtightness but also prevents the generation of particles, making it an extremely innovative coupling for semiconductor manufacturing.

[Brief explanation of drawings]

FIG. 1 is a half-sectional view showing an embodiment of the present invention, FIG. 2 is a perspective view of the sleeve of the present invention, and FIG. 3 is a
A partially cutaway perspective view of the gasket of the present invention, FIGS. 4 and 5 are sectional views showing other embodiments of the rotating means, and FIG. 6 is a sectional view showing a conventional fluid coupling. In the figure, 11...Body, 12...Sleeve, 1
3... Cap nut, 14... Threaded portion, 15... Gasket, 16... Short annular portion, 17... Small ball, 18
...Ring-shaped groove, 19...Ring-shaped coil spring, 20...Metal tube.

Claims (1)

[Claims] 1. A body provided with a threaded portion on the outer periphery of one end of the tube;
A sleeve consisting of a tubular body having a short annular portion on the outer periphery of the tip that contacts and communicates with a through hole on the threaded portion side of the body via a gasket, and a sleeve that is fitted into the sleeve and screwed into the threaded portion of the body. In a fluid coupling consisting of a cap nut that firmly tightens the body and the sleeve, a rotating means is provided on the abutment surface between the tube side surface of the sleeve and the cap nut, and the gasket has a ring shape. A height for semiconductor manufacturing equipment, characterized in that a coil spring is held by a metal tube having a C-shaped cross section, and a roll burnishing surface is formed on the surface where the body and sleeve come into contact via a gasket. Airtight bag nut tightening fluid fitting. 2. A body having a threaded portion on the outer periphery of one end of the tube;
A sleeve consisting of a tubular body having a short annular portion on the outer periphery of the tip that contacts and communicates with a through hole on the threaded portion side of the body via a gasket, and a sleeve that is fitted into the sleeve and screwed into the threaded portion of the body. In a fluid coupling comprising a cap nut that firmly tightens the body and the sleeve, a rotating means is provided on a contact surface between the pipe side surface of the sleeve and the cap nut, and the body and the sleeve are fastened together. A fitting recess and a fitting protrusion are respectively provided on the contact surfaces of the gasket so that the end face of the fitting recess comes into contact with the step of the fitting protrusion so that the gasket is not compressed by more than the effective elastic compression amount. The semiconductor is characterized in that a ring-shaped coil spring is held by a metal tube having a C-shaped cross section, and a roll burnishing treated surface is formed on the surface where the body and sleeve come into contact via a gasket. Highly airtight bag nut tightening fluid coupling for manufacturing equipment.