JPH08100875A - Pipe joint - Google Patents

Abstract

PURPOSE: To air-tightly connect the fellow pipes easier by a general use tool with no welding work required, in a pipe joint connecting the pipes. CONSTITUTION: A pipe joint comprises a metal gasket 1 interposed by end parts of pipes 8 connected, retainer sleeves 2 fixedly tightened to the pipes 8 by pressing force of a back ferrule 5 through a front ferrule 3 and female/ male nuts 6, 7 giving to the pipe force of fastening the metal-made gasket interposed through this retainer sleeve 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe joint, and more particularly to a pipe joint for pipes used in equipment in the semiconductor manufacturing field and requiring high cleanliness.

[0002]

2. Description of the Related Art Conventionally, it has been necessary to pump harmful gas or highly pure gas without leakage through piping in semiconductor manufacturing facilities or various facilities in factories. Therefore, as these pipes and pipe joints, stainless steel pipes and joints with less rust and pollution have been used. Further, the piping in the semiconductor manufacturing facility is not limited to simple straight piping, but the piping system is complicated such that the piping is detoured to the outside or bent inside. Therefore, in addition to bending the pipes, pipe joints were used to cope with the necessary pipes for forming the complicated pipe paths.

However, as described above, the leakage of the pipe in the semiconductor manufacturing facility is extremely strictly required, and even if the pipe itself is not leaked, the pipe joint is leaked, often resulting in an unexpected accident. In addition, in order to construct complicated pipes with different piping systems depending on individual equipment such as semiconductor manufacturing equipment, in many cases on-site individual The so-called physical matching work is performed, in which the length of the pipe is determined and bent according to the equipment and connected with a joint. For this reason, a high degree of skill was required to ensure complete piping. Under such circumstances, various pipe joints capable of completely connecting leaks have recently been proposed.

FIG. 3 is a sectional view of a conventional pipe joint showing an example. There is a pipe joint shown in FIG. 3 as an example of a pipe joint that is more resistant to corrosion and more reliably connects pipes without leakage. As shown in the figure, this pipe joint is welded to the end of each pipe 8 to which the sleeves 12 and 13 holding the metal gasket 11 by the convex portion of the end face to be connected are welded, so The external thread of the sleeve 13 of the other pipe 8 is pushed into the cap nut 14 that has been passed through to apply a tightening force to the metal gasket 11 and connect airtightly.

The metal gasket 11 of this pipe joint is made of stainless steel having a low hardness and not easily rusting, and the projections of the stainless steel sleeves 12 and 13 having a relatively high hardness are made to bite into the surface of the metal gasket 11 for airtightness. It was characterized by keeping.

[0006]

In the above-mentioned conventional pipe joint, although the pipes can be connected airtightly, the pipe and the sleeve must be welded. However, it is difficult to bring a welding machine for welding into a semiconductor factory, which is a narrow space where fire is strictly prohibited. Further, even if welding is carried out at another factory, there is a drawback that not only the leak inspection after the welding but also the number of man-hours other than the welding required for transportation to the site is required, which not only increases the cost but also shortens the construction period.
In addition, the gas flowing to the weld overlay inside the pipe is adsorbed,
There is a problem that when adhering the gas of another material, the adhered gas is released and the purity of the gas of the other material is lowered.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a pipe joint in which pipes can be hermetically connected to each other more easily with a general-purpose tool without requiring welding work.

[0008]

A feature of the present invention is that in a pipe joint for connecting pipes to each other in an airtight manner through gaskets, a ring-shaped metal gasket held between end faces of the pipes to be connected, A pair of retainer sleeves each having a first female taper portion at the other end formed so as to be spaced apart from the metal gasket and have one end positioned to hold the pipe through and to enter the center from the outer periphery, A second female formed through each of the pipes and in contact with the first female taper portion of the retainer sleeve and having a first male taper portion with the same inclination at one end and entering from the outer periphery to the center. It has a pair of front ferrules having a tapered portion at the other end, and an inclined surface which passes through the respective pipes and is steeper than the second female tapered portion of the front ferrule. A pair of back ferrules having a second male taper portion that abuts the female taper portion at one end and a flat surface at the rear end, and a pair of back ferrules that pass through the respective pipes and contact the flat surface of the back ferrule. A pair of ring-shaped washers each having a flat surface in contact with each other, through each of the pipes and sandwiching the metal gasket, the retainer sleeve, the front ferrule, the back ferrule, and the washer are formed in a beaded shape in this order. A pipe joint including a pair of male and female nuts that encloses the arranged ones and gives a tightening force for tightening the metal gasket to the pipe.

[0009]

The present invention will be described below with reference to the drawings.

1 (a) and 1 (b) are a sectional view and a partially enlarged schematic sectional view of a pipe joint for explaining an embodiment of the present invention. As shown in FIG. 1 (a), this pipe joint has a ring-shaped metal gasket 1 held between the end faces of the pipes 8 to be connected, and one end portion of which is located away from the metal gasket 1 and the pipe 8 And a pair of retainer sleeves 2 each having a female tapered portion 9a formed at the other end so as to enter the center from the outer periphery and the respective pipes 8 and pass through the retainer sleeve 2
A pair of front ferrules 3 each having a male taper portion 9b having the same inclination and abutting against the female taper portion 9a and having a female taper portion 10a formed to enter the center from the outer periphery, Male taper portion 10b which passes through the pipe 8 and has an inclined surface steeper than the female taper portion 10a of the front ferrule 3 and which abuts the female taper portion 10a.
A pair of back ferrules 5 each having one end and a flat surface at the rear end, and a pair of ring-shaped washers 4 having flat surfaces that pass through the respective pipes 8 and contact the flat surface of the back ferrule 5. And the retainer sleeve 2 through the respective pipes 8 and sandwiching the metal gasket 1.
A front ferrule 3, a back ferrule 5, and a washer 4, which are arranged in a beaded pattern in the order of facing each other, and are provided with a pair of male and female nuts 6 and 7 for giving a tightening force for tightening the metal gasket 1 to the pipe 8. There is.

Here, the fact that the ferrule is divided into two and the washer 4 is provided prevents the rotational force generated when the male nut 7 is screwed into the female nut 6 from being transmitted to the retainer sleeve 2 at all. Also, back ferrule 5
As shown in FIG. 1 (b), the component force F with respect to the tightening force P is
Is given to the retainer sleeve 2 via the front ferrule 3, the inclined surface of the male taper portion 10b of the back ferrule 5 is steeper than the inclined surface of the female taper portion 10a of the front ferrule 3. This component force F acts on the retainer sleeve 2 and becomes a holding force of the retainer sleeve 2 on the pipe 8. Therefore, by screwing the male nut 7 into the female nut 6, the retainer sleeve 2 is clamped and fixed to the pipe 8 by the component force F, and at the same time, the metal gasket 1 is sandwiched in the pipe 8 by the tightening force P.

The male nut 7, the female nut 6, the washer 4, the front ferrule 3, the retainer sleeve 2 and the back ferrule 5 are all made of rust-resistant stainless steel, and in particular, the back ferrule 5 is a martensite type in the sense of having springiness. It is desirable to make it from stainless steel.
The metal gasket 1 is preferably made of a pure nickel material having a low hardness, but stainless steel may be used if importance is attached to corrosion resistance.

2 (a) to 2 (c) are cross-sectional views showing the procedure of assembling the pipe joint shown in FIG. 1 in the order of assembling. First, the retainer sleeve 2 is fixed at a predetermined distance from the end surface of the pipe 8 to be connected. As shown in FIG. 2A, this includes a male nut 7 or a female nut 6, a washer 4,
The back ferrule 5, the front ferrule 3, and the retainer sleeve 2 are inserted into the respective pipes 8 in this order. Next, the jig 15 is sandwiched between the ends of the pipe 8. Then, the male nut 7 and the female nut 6 are engaged with each other to apply a tightening force to the jig 15, and at the same time, the position of the retainer sleeve 2 is fixed.

Next, as shown in FIG. 2B, the male nut 7 and the female nut 6 are loosened and disengaged, and the jig is taken out. At this time, the retainer sleeve 2 is fixed to the pipe 8 by the leverage force by the pressing force of the back ferrule 5 via the front ferrule 3. The retainer sleeve 2, the front ferrule 3 and the back ferrule 5 are fixed to the pipe 8 as if they were integrated.

Next, as shown in FIG. 2 (c), the metal gasket 1 is sandwiched and held between the ends of the pipe 8, and the male nut 7 and the female nut 6 are meshed and screwed together so that both surfaces of the metal gasket 1 are piped. Tighten at the end of 8. As a result, the pipe 8 is airtightly connected. For pipes with a large diameter, the edges should be sharpened with a file or the like, if necessary. By the way, when I tried to connect 1/2 inch pipes, the work was completed in a very short time of less than 1 minute. In addition, this work has an advantage that only one wrench, which is a general-purpose tool, is sufficient.

[0016]

As described above, according to the present invention, the metal gasket sandwiched between the end portions of the pipe, the member tightened and fixed to the pipe by the pressing force of the screw, and the metal gasket sandwiched through this member. By providing the male and female nuts that give a tightening force to the pipe, there is an effect that the pipe can be more easily airtightly connected using a general-purpose tool without welding.

[Brief description of drawings]

FIG. 1 is a sectional view and a partially enlarged schematic sectional view of a pipe joint for explaining an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing the procedure for assembling the pipe joint of FIG. 1 in the order of assembling to explain the procedure.

FIG. 3 is a cross-sectional view of a pipe joint showing a conventional example.

[Explanation of symbols]

 1,11 Metal gasket 2 Retainer sleeve 3 Front ferrule 4 Washer 5 Back ferrule 6 Female nut 7 Male nut 8 Piping 12,13 Sleeve 14 Cap nut 15 Jig

Claims (1)

[Claims] 1. A pipe joint for airtightly connecting pipes via a gasket, comprising a ring-shaped metal gasket held between end faces of the pipes to be connected,
A pair of retainer sleeves each having a first female taper portion at the other end formed so as to be separated from the metal gasket and have one end positioned to hold the pipe through and to enter the center from the outer periphery, Second female taper formed through the pipe and abutting against the first female tapered portion of the retainer sleeve at one end and having the same inclination at the one end and entering from the outer periphery to the center Pair of front ferrules each having the other end portion, and a second male taper that passes through the respective pipes and has an inclined surface steeper than the second female taper portion of the front ferrule and abuts on the female taper portion A pair of back ferrules each having one end at one end and a flat surface at the rear end, and passing through the respective pipes and contacting with the flat surface of the back ferrule. A pair of ring-shaped washers each having a flat surface, and the retainer sleeve, the front ferrule, the back ferrule, and the washer are arranged in a beaded pattern in this order with the metal gaskets sandwiched through the respective pipes. A pipe joint, comprising: a pair of male and female nuts that wraps around the container and applies a tightening force for tightening the metal gasket to the pipe.