JPH0663587B2 - Pipe fitting - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a pipe joint, and is particularly used in the field of semiconductor industry where perfect sealability is required.

[Prior Art] For example, in the semiconductor industry field such as IC and LSI, the work is performed in a clean room in which fine particles are excluded, and the environment and conditions of the manufacturing work are more severe. The special gas used in the semiconductor manufacturing is introduced into the room from the outside of the clean room through a pipe, but it is extremely disliked that other unnecessary gas molecules such as air are mixed into the special gas. For this reason, not only pipes but also pipe joints that connect pipes to each other are required to be ultra-precision.
Further, in the case of a pipe joint such as a high pressure gas container, a perfect sealing property is required from the viewpoint of safety.

The conventional pipe joint is generally constructed as shown in FIG.

That is, the one piece 1 hermetically attached to the one pipe 1
No. 0 and the other piece 20 hermetically attached to the other pipe 2, a metal gasket 30 is interposed, and both pieces 10, 20 are axially tightened with a cap nut 5 to seally connect both pipes 1, 2. Is.

Here, in order to improve the sealing property, the tightening force between the pieces 10 and 20, that is, the pressing force of the metal gasket 30 may be increased. However, in the embodiment shown in FIG. 5, since the metal gasket 30 and the pipes 1 and 2 are twisted and deformed by the turning force of the cap nut 5, it is impossible to secure a tightening force above a certain value. As a solution to this problem, the applicant has a means (not shown) that transmits an axial force but does not transmit a rotational force between the inner surface of the cap nut 5 and the inner surface of the other piece 20.
As a related art, a mechanism has been proposed in which a thrust bearing is interposed, and a thrust bearing having a diameter larger than the inner diameter of the cap nut 5 is mounted to dramatically increase the tightening force.

On the other hand, regarding the relationship between the two pieces 10 and 20 and the metal gasket 30 for improving the sealing property, the pressing surface 15 of the one piece 10 and the pressing surface 25 of the other piece 20 are mirror-finished from the viewpoint of smoothing the contact surface. In addition, it is said that the metal gasket 30 having a C-shaped cross section is adopted so that excellent crushing characteristics and residual elastic characteristics can be obtained, and the economical efficiency of reusing the metal gasket 30 is satisfied. In this way, perfection of the seal is intended by making each component extremely sophisticated.

[Problems to be Solved by the Invention] However, in the above-described conventional pipe joint structure, no matter how elaborate the constituent elements are, due to practical problems in handling, it is not always possible to sufficiently exhibit their functions, and a perfect seal cannot be obtained. I had the problem of not being able to achieve it.

That is, although the connection mode shown in FIG. 5 is ideal,
In this mode, the one piece 10 is shifted by 90 degrees from the illustrated state to be in a vertical state, the metal gasket 30 is accurately positioned on the surface of the pressing surface 15 about the axis P, and the other piece 20 is in a vertical state. It can be established only when both pieces 10 and 20 can be pressed in the axial direction without being twisted.

However, it is extremely difficult to achieve the above-mentioned connection in practical use. That is, when the pipe 1 (2) is in the horizontal state or the inclined state, the metal gasket 30 is likely to fall off the floor surface or the ground during the preparation. Once removed, foreign matter such as dust adheres to the surface of the metal gasket 30 or is scratched, so that the desired sealing performance cannot be expected. When the metal gasket 30 is pressed with a finger in order to prevent this, human oil and sweat adhere to the surface of the metal gasket 30, and the sealing property is impaired in this case as well. If the metal gasket 30 is not correctly positioned with respect to the piece 10, the pipe 1,
There is also a problem that the cross section of the connecting passage between the two is reduced. Further, since the metal gasket 30 cannot be expanded and deformed in both directions (the direction orthogonal to the pressing direction), the pressing surface 15 and the metal gasket 30 themselves may be worn or damaged and may not be reused.

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and an object and object thereof is to provide a pipe joint which is easy to handle and can achieve a perfect seal.

[Means for Solving Problems] The present invention focuses on the fact that solution of handling problems is extremely important for achieving a perfect seal from the analysis of a large number of actual connection works, and a metal gasket is manually operated at a work site. It is formed so that it can be assembled quickly and easily without touching the metal gasket, and that the metal gasket can sufficiently exhibit its crushing characteristics.

Specifically, in a pipe joint for sealingly connecting one piece and the other piece with a metal gasket interposed between both pieces in the axial direction, the metal is added to one of the one piece and the other piece. Providing a holding portion that engages with the peripheral surface of the gasket to hold the metal gasket so that it does not fall off the piece, and allows radial expansion deformation in all directions around the axis of the metal gasket held by the holding portion And a diameter-expansion allowance space is formed.

[Operation] In the present invention having the above-described configuration, since the metal gasket is attached and held by the holding portion provided on the tip side of one of the pieces, it is necessary to drop the metal gasket or touch it during the preparation work. And the metal gasket can be fixed in place. Moreover, the metal gasket can be radially deformed in all directions at the time of tightening due to the diameter expansion allowance space formed on the tip end side of the piece corresponding to the holding portion, and uneven wear and friction with the pressing surface are small. Therefore, a long-term perfect seal can be achieved.

[Embodiment] A preferred embodiment of the pipe joint according to the present invention will be described in detail with reference to the drawings.

(First Embodiment) As shown in FIGS. 1 and 2, a pipe joint of this embodiment has a one piece 10 integrated with one pipe 1, another piece 20 integrated with another pipe 2, and a metal gasket 30. And cap nut 5
It consists of and. Further, a thrust bearing 8 is interposed between the one piece 10 and the cap nut 5 at the position shown in FIG.

On the other hand, a small diameter protrusion 14 is provided on the tip side of the piece 10. The outer diameter centered on the axis P of the small-diameter protruding portion 14 is D
A circular arc-shaped recess 13 is formed on the front side. Here, the portion having the outer diameter D constitutes the holding portion 12. The holding portion 12 engages with the peripheral surface 31a of the metal gasket 30 which will be described later in detail, and holds the metal gasket 30 in one piece 1.
It is held so as not to drop from 0. In addition, due to the space formed between the inner surface of the concave portion 13 and the convex portion 21 of the other piece 20 and the side of the opening portion 36 of the metal gasket 30 which will be described later, all directions about the axis P of the metal gasket 30 (see FIG. 1). , A radial expansion allowable space for allowing the radial expansion deformation in the vertical direction in FIG. 2) is formed. Further, the root surface of the small-diameter protruding portion 14 forms the pressing surface 15 and is mirror-finished. In addition, 16 is a stop surface.

An annular convex portion 21 is provided on the tip side of the other piece 20, and a stop surface 26 corresponding to the stop surface 16 is formed on the tip side of the convex portion 21. It cooperates with the stop surface 16 to prevent excessive deformation of the metal gasket 30. Also. The pressing surface 25 is mirror-finished like the pressing surface 15.

Further, a screw 6 that is screwed into the cap nut 5 is provided on the outer peripheral surface of the other piece 20, and a thrust bearing 8 is provided between the cap nut 5 and the one piece 10. The thrust bearing 8 is formed of a plurality of balls and a pair of annular plates, and is retained in the cap nut 5 in a stable posture by a retainer 9 fitted in the groove 7 of the cap nut 5.

Therefore, since the one piece 10 and the cap nut 5 are screwed together, the two pieces 10 and 20 can be approached and separated from each other in the axis P direction by rotating the cap nut 5, and the cap nut is actuated by the action of the thrust bearing 8. The rotational force of 5 is not transmitted to both pieces 10 and 20, the metal gasket 30 and the like, and can be tightened with a large force of both pieces 10 and 20.

Although the use of this pipe joint is not limited, the other piece 20 is attached to the discharge pipe (2) of the high-pressure gas cylinder in this embodiment.

As shown in FIG. 1 showing a tightened state and FIG. 2 showing a state in which the metal gasket 30 is not yet tightened, the metal gasket 30 in this embodiment has an annular appearance as a whole, and its cross-sectional shape has both end portions 35, 35. It is C-shaped apart. In FIG. 2, which shows the cross section of the metal gasket 30 in detail, reference numeral 31 denotes an outer cover made of a metal material having a relatively low hardness. The metal material is nickel, aluminum, tin or the like, or an alloy thereof, but in this embodiment, it is made of nickel. 36 is an opening.

The inner diameter d of the metal gasket 30 is smaller than the outer diameter D of the engaging portion 12. On the other hand, the outer diameter d ₁ is the other piece 2
It is smaller than the inner diameter D1 of the convex portion 21 of 0. A spring 32 is made of a metal material having a hardness higher than that of the outer cover 31. Stainless steel is used in this embodiment, but may be formed of a common spring material such as phosphor bronze.

The outer peripheral surface of the spring 32 is in close contact with the inner peripheral surface of the outer cover 31. A spring 32 is fitted to the outer cover 31 or the spring 32
It can be assembled simply by fitting the outer skin 31 onto the cover.
Here, since the hardness of the outer cover 31 is low, both pieces 10, 20
The spring 32 retains the residual elastic property.

In FIG. 2, the gap C is a crushing margin of the metal gasket 30.

Here, the relationship between the one piece 10 and the metal gasket 30 will be described. When the metal gasket 30 is inserted into the small-diameter protruding portion 14 of the one piece 10 from the left side in FIG. , The peripheral surface 31a is hooked on the engaging portion 12, but by further pressing, the inner diameter d
The part fits into the recess 13 beyond the engaging part 12.

Once fitted, since the inner diameter d is smaller than the outer diameter D, the metal gasket 30 does not fall off the one piece 10 even if the one piece 10 is tilted. For this reason, the outer diameter D of the engaging portion 12 is appropriately selected from the inner diameter d of the metal gasket 30 and the material of the outer skin 31 thereof. In this embodiment, since the outer cover 31 is made of nickel, the outer diameter D is set to be larger than the inner diameter d by 1 mm in consideration of the elastic deformation amount and the reduction of the resistance to the forced removal of the metal gasket 30.

Next, the operation will be described.

On the other hand, the metal gasket 30 is attached to the small-diameter protruding portion 14 of the piece 10.
And push in. The metal gasket 30 has a peripheral surface 3
1a is locked by the holding portion 12 and cannot be disengaged from the one piece 10 in a natural state. Therefore, even if the orientation and orientation of the one piece 10 are different, the metal gasket 30 does not fall off from the one piece 10.

Further, the gasket 30 has the axis P due to the holding portion 12.
Since the metal piece 30 is held centered on the other side, it is not necessary to correct the position of the metal gasket 30 with respect to the one piece 10, and the other piece 20 can be inserted without touching a human hand, and the preparation work can be performed quickly.

When the cap nut 5 is rotated and the metal gasket 30 is pressed by the pressing surfaces 15 and 25 of the two pieces 10 and 20, the metal gasket 30 is gradually deformed and the outer skin 31 is pressed against the pressing surface 1.
It grows in the radial direction while adapting to 5,25. Meanwhile, piece 10
A recess 13 is provided in the inner surface of the other piece 20, and a space is formed between the inner surface of the protruding portion 21 of the other piece 20 and the opening 36 side of the metal gasket 30. The space and the recess 13 form a diameter-expansion allowance space. Therefore, the metal gasket 30 has an axis P
The diameter can be expanded and deformed in all directions around the
Less friction with 25.

Further, the thrust bearing 8 does not twist the metal gasket 30, the pipes 1, 2, etc.

Thus, both stop surfaces 16,2 of both pieces 10,20
By rotating the cap nut 5 until the 6 abuts, a perfect sealing connection can be made.

On the other hand, when the connection is released, the cap nut 5 may be rotated in the opposite direction to the above case to separate the two pieces 10, 20. In this case, when the two pieces 10 and 20 (pressing surfaces 15 and 25) start to separate from each other, the metal gasket 30 returns to its original shape due to the restoring property of the spring 32. It is also possible to remove the metal gasket 30 from the holding portion 12 by the force. Therefore, the metal gasket 30 can be reused.

According to this embodiment, however, since the metal gasket 30 is held on the one piece 10 by the holding portion 12, the metal gasket 30 does not fall off to the floor surface or the like during work preparation as in the conventional case, and Also, since it is not necessary to manually correct the posture of the metal gasket 30 with respect to the one piece 10, the connection work can be performed quickly and easily regardless of the orientation and posture of the pipes 1 and 2, and the metal gasket 30 is free from dust. Since it is not attached or scratched, high sealing performance can be guaranteed.

Further, the holding portion 12 is integrally provided on the one piece 10, and the concave portion 13 is provided on the one piece 10 side and the outside of the metal gasket 30 (on the opening 36 side) and the convex portion 21 of the other piece 20. Since a space is formed between the inner surface and the recess 13 and the space for allowing the diameter expansion is formed, the metal gasket 30 can be allowed to undergo radial deformation in all directions. Therefore, there is no inconvenience of being deformed in only one direction as in the conventional case, and the sealing property can be further improved from this point as well.

Further, the metal gasket 30 is formed of the outer skin 31 and the spring 32, and is held in the holding portion 12 by utilizing its elasticity. Therefore, the metal gasket 30 has a simple structure, is economical, and is reusable.

Further, since the thrust bearing 8 is interposed between the other piece 20 and the cap nut 5, the pipes 1 and 2 as well as the metal gasket 30 are not twisted and deformed, and a perfect seal and long-term use are obtained. And can be guaranteed. Thus, a perfect seal can be achieved by fully exerting the function of each individual component and the combination thereof, which have been elaborated on the basis of design, and the connection work is greatly facilitated. Pipe fittings can be provided.

In addition, in the first embodiment, the tip of the small-diameter protruding portion 14 of the one piece 10 is formed into an arc shape to form the holding portion 12, but the point is that the metal gasket 30 is held by the one piece 10 so as not to fall off. I wish I could
The form can be appropriately selected and determined and implemented.

Similarly, the form of the diameter expansion allowable space of the metal gasket 30 can be appropriately selected.

(Second Embodiment) A second embodiment is shown in FIGS. 3 and 4.

In the second embodiment, the metal gasket 3 is the same as the first embodiment.
0 is fitted to the small-diameter protruding portion 14 of the one piece 10 and the holding portion 12 is engaged with the inner periphery of the one-piece piece 10, whereas the storage recess 11 is formed on the tip side of the one piece 10. Then, the holding portion 12 is fitted into the recess 11 to engage the holding portion 12 with the outer peripheral surface (on the side of the opening 36) of the metal gasket 30.

That is, as shown in FIG. 3 which is an enlarged view of a main part, a large arc-shaped recess 13 (diameter expansion allowance) is formed on the inner surface of the storage recess 11 provided in the one piece 10 to allow radial deformation of the metal gasket 30. A space) is formed, and a protrusion-shaped holding portion 12 is formed on the outside facing the space.

Therefore, when the metal gasket 30 is fitted into the storage recess 11 of the one piece 10, the metal gasket 30 is held by the holding portion 12 so as not to fall off. In this case, for convenience of removing the metal gasket 30 by applying a forcing force, the one piece 10 is provided with grooves 29, 29 prepared from the tip side toward the recess 13. A screwdriver or the like can be inserted into the groove 29 to remove the metal gasket 30 from the storage recess 11.

A relief 28 is provided on the tip side of the other piece 20 in order to expand the application of the shapes and sizes of the holding portion 12 and the metal gasket 30.

Therefore, also in the second embodiment, as in the case of the first embodiment, the metal gasket 30 can be prevented from falling off and the metal gasket 30 can be deformed in the radial direction.

In each of the above embodiments, the holding portion 12 is used as the one piece 1
However, the holding portion 12 may be separately manufactured and attached to the one piece 10 for the convenience of manufacturing. Obviously, the holding portion 12 may be provided on the other piece 20 side.

Further, the metal gasket 30 is composed of the outer skin 31 and the disc-shaped spring 32, but the form is not limited to the above disclosed range, and for example, the spring 32 may be a coil spring and the outer skin 31 may have a high hardness. .

EFFECTS OF THE INVENTION As is apparent from the above description, the present invention provides a holding portion for holding a metal gasket on one of the one piece and the other piece, and expands the diameter of the metal gasket held by the holding portion in all directions. Since it has a structure in which a diameter expansion allowance space that allows deformation is formed, it has an excellent effect that it is easy to handle under a quick and simple connection work, and a perfect sealing property can be guaranteed.

[Brief description of drawings]

FIG. 1 is a side sectional view showing a first embodiment of a pipe joint according to the present invention, FIG. 2 is a side sectional view of an essential part similarly omitting the upper side, and FIGS. 3 and 4 show a second embodiment. FIG. 3 is a side sectional view of an essential part, FIG. 4 is a front view of one piece seen from the other piece side, and FIG. 5 is a side sectional view of a conventional pipe joint. 10 ... One piece, 12 ... Holding part, 13 ... Recessed part, 20 ... Other piece, 30 ... Metal gasket, 31 ... Outer skin, 31a ... Peripheral surface

Claims (1)

[Claims] 1. A pipe joint for connecting one piece and the other piece in a sealed manner by axially tightening a metal gasket interposed between the pieces, wherein one of the one piece and the other piece is made of the metal. Providing a holding portion that engages with the peripheral surface of the gasket to hold the metal gasket so that it does not fall off the piece, and allows radial expansion deformation in all directions around the axis of the metal gasket held by the holding portion A pipe joint characterized in that a permissible diameter expansion space is formed.