JPH07229588A - Screw-in type joint - Google Patents

Abstract

PURPOSE:To fundamentaly eliminate leakage due to a slide scratch, which is generated in fastening and. is the cause of most of lekage in a screw--in type joint part, on a seal face. CONSTITUTION:A screwed type joint consists of a female nut 1, a pipe male screw member 3, and an intermediate screw member 5, in which a screw to be screwed into the thread of the female nut is provided in the outside diameter while a screw to be screwed into the male screw is provided in the inside diameter. The intermediate screw member 5 is machined so as to have a normal thread relation provided with different pitches between threads on the inside diameter and the outside diameter, or so as to have a reverse thread relation provided with the same pitch or different pitches on the inside diameter and the outside diameter.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe joint used for a gas control system in semiconductor manufacturing equipment and various advanced fields.

[0002]

2. Description of the Related Art Normally, in semiconductor manufacturing equipment and pipe fittings in various advanced fields, a metal ring, a Die Freon gasket, or a metal gasket is inserted between the welding pieces with flanges, and a tightening seal is made with male and female nuts. There is.

[0003]

However, in the above-mentioned conventional threaded pipe joint, when a metal ring or gasket is fastened to the mating surface of the welded piece with a flange only with the male screw member and the female nut, the sealing surface is Then, opposite sliding occurs. Further, as the tightening pressure is increased, a larger sliding force is also generated in the opposite direction at the time of closing. As a result, slippage and sometimes seizure occur on the slip surface, which causes leakage. In that case, it cannot be reused, and all of them will be replaced.

The present invention provides a pipe joint that fundamentally solves the problem of leakage due to slip damage on the seal surface at the time of shutting off, which is the cause of most of the leakage in the screw-in type pipe joint. Therefore, an object of the present invention is to provide a pipe joint having a mechanism in which no sliding force is generated on the sealing surface of the screw-in type pipe joint and only the face-to-face pressure required for sealing is increased.

[0005]

In order to solve the above-mentioned problems, the present invention adds no intermediate screw to the conventional screw-in type pipe joint so that no sliding force is generated on the sealing surface.
(EN) Provided is a pipe joint having a mechanism for increasing only the facing pressure required for sealing.

In the first aspect of the present invention, a female nut,
A tubular male screw member, and an intermediate diameter screw member having an outer diameter having a large pitch screw screwed into the screw of the female nut, and an inner diameter having a small pitch screw screwed into the male screw, and having an inner diameter screw and an outer diameter member. A threaded pipe joint is provided in which the screw is processed in a forward thread relationship.

According to a second aspect of the present invention, a female nut,
It consists of a male screw member and an intermediate screw member that has a screw that is screwed into the screw of the female nut in the outer diameter and a screw that is screwed into the male screw in the inner diameter, and the screw of the inner diameter and the screw of the outer diameter are processed in a reverse screw relationship. There is provided a screw-in type pipe coupling.

In these cases, the pair of pipes to be joined by the screw type pipe joint of the present invention, when the female nut and the male screw member arranged around them are pulled together by the rotation of the intermediate screw member and tightened, the butting surfaces are not joined. Only the force in the tube axis direction acts, and the rotating action does not act. Therefore, it is preferable to use a pair of precisely-wrapped flanged annular pieces at the ends to be joined of the pipe, and the pair of wrapped-up flanged annular pieces are mutually connected by the female nut and the tubular male screw member of the pipe joint. It is designed to be pressed in the direction.

In a more preferred example, a press washer is inserted between the shoulder provided on the female nut and the outer surface of one of the collars and tightened as described above, while the outer peripheral surface of the press washer is fixed to the intermediate screw member. By engaging the tip in the tightening direction and pressing the outer circumference of the press washer by tightening the intermediate screw member, the inner circumference of the press washer is strongly pressed against the brim of the tubular piece with the brim by the principle of leverage, thereby providing the sealing pressure. Can be increased.

[0010]

With the above-described structure, in the first aspect, the intermediate screw member and the male nut are combined in advance and assembled so that the end face of the annular piece is lightly contacted, and then the female nut and the male nut are fixed. By tightening only the intermediate screw member, the female nut shifts in parallel by the difference between the outer screw pitch and the inner screw pitch of the screw member, or becomes a parallel tightening force. Alternatively, in the case of the inner and outer reverse screws, they move by a double pitch or work as a parallel tightening force. Further, the present invention is a pipe joint having a mechanism in which a special intermediate screw member and a press washer are added to the screw-in type joint so that no sliding force is generated on the sealing surface and only the facing pressure required for sealing is increased. As a result of the present invention, it is possible to seal the wrapped end face of the joint portion, which was not possible in the past, without the need for seal packing, and there is no slippage on the sealing surface, and it is always necessary when reused with a conventional seal packing insertion type joint. The seal packing that is said to be unnecessary.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIGS. 1 and 2 show a pipe joint according to a first embodiment of the present invention.
In this embodiment, the pipe joint is screwed into the female nut 1 having a large-pitch female thread 7 cut in the inner diameter, a tubular male screw member 3 having a small-pitch male thread 9 cut in the outer diameter, and the female thread 7 of the female nut having an outer diameter. It has a large-pitch male thread 11, and a small-pitch female thread 13 to be screwed into the male thread 9 in the inner diameter.
The intermediate screw member 5 having is as a basic element. The female screw 13 having the inner diameter and the male screw 11 having the outer diameter of the intermediate screw member 5 are processed in a forward screw relationship, and correspondingly, the female screw 7 of the female nut 1 and the male screw 9 of the tubular male screw member are processed in the same pitch relationship. Has been done. It should be noted that all of these screws are processed in the same direction, for example, as a right screw. When the screws are processed in this manner, these members 1, 3, 5 and the pair of insert pieces with flanges described below are assembled to make the flanges collide with each other, and then the intermediate screw member 5 is attached to the other members 1, 3 When rotated with respect to, the female nut is attracted toward the male screw member because the pitch of the screw of the outer diameter is larger than that of the screw of the inner diameter.

The preferred ends of the tubes to be joined by the threaded tube fitting of the present invention consist of a pair of bayonet weld pieces 15, 17 as shown. In these plug-in welding pieces, a tubular piece with flanges 19 and 21 precisely lapped is provided on the inner end of a tubular portion having an outer diameter that can be inserted into the female nut 1 and the male screw member 3. The outer surfaces of the collars 19 and 21 in the axial direction are engaged with the shoulders of the female nut 1 and the tubular male screw member, respectively, and the lapping end surfaces are pressed against each other in the axial direction by screwing both members.

While the above construction is sufficient for practicing the present invention, in order to further enhance the sealing action of the butt end faces of the tubular piece, preferably between the female screw nut 1 and the brim 19 of the butt welding piece 15. Press washer 2
Intervene 3. In this case, it is desirable to act on the flange 19 of the butt welding piece 15 with a portion closer to the outer diameter than the inner peripheral portion of the female screw nut 1 as a fulcrum. The intermediate screw member 5 facing the outer peripheral surface of the washer 23.
Opposite the annular extensions 25 of. As described below, when the intermediate screw member 5 is tightened, the ring-shaped extension portion 25 becomes the washer 23.
1, the washer 23 rotates around the fulcrum, and the lever action pushes the butt welding piece 15 to the right in FIG. The outer circumferences of the female nut 1 and the intermediate screw member 5 are formed in a polygonal shape so as to receive a spanner.

Embodiment 2 In the second embodiment, it is composed of a female nut, a male screw member, and an intermediate screw member having an outer diameter with a screw screwed into the screw of the female nut and an inner diameter with a screw screwed into the male screw. It is characterized in that the inner diameter screw and the outer diameter screw are processed in a reverse screw relationship. Members corresponding to the screw type joint of the first embodiment are designated by the same reference numerals, and only different portions will be described. 2-3,
The female screw 13 having the inner diameter and the male screw 11 having the outer diameter of the intermediate screw member 5 are processed in a reverse screw relationship, and correspondingly, the female screw 7 of the female nut 1 and the male screw 9 of the tubular male screw member are processed in the same relationship. ing. When the screws are processed in this way, these members 1, 3, 5 are assembled with a pair of insert pieces with flanges so that the flanges substantially abut each other, and then the intermediate screw member 5 is attached to the other members 1, 3. When rotated, the female nut is pulled towards the male threaded member. The press washer is not used in this example, but it can be used if desired.

With the above-mentioned structure, in the first embodiment, the intermediate screw member 5 and the male screw member 3 are combined in advance, and the tubular pieces 15 and 17 are assembled so that the brim end surfaces of the tubular pieces 15 and 17 are lightly touched. Next, by fixing the female nut 1 and the male screw member 3 and tightening only the intermediate screw member, the female nut 1 shifts in parallel by the difference between the outer screw pitch and the inner screw pitch of the male screw member 3 or a parallel tightening force is applied. Become.
Alternatively, in the case of the inner / outer reverse screw of the second embodiment, it moves by a double pitch or acts as a parallel tightening force. In addition, the present invention includes a special intermediate screw member and a special washer 23 in the screw joint.
By adding the above, no sliding force is generated on the sealing surface, and only the facing pressure required for sealing can be increased.

[0016]

As a result of the present invention, it is possible to seal the end faces of the lapped joint portion, which has been impossible in the past, and there is no slip damage on the sealing surface, and it is absolutely necessary for reuse in the conventional seal packing insertion type joint. There is no need for seal packing. In addition, there is no co-rotation at the time of tightening, there is no generation of particles that are transmitted to the seal surface due to rubbing, etc. Also, by lapping the mating surface, it becomes a metal touch seal that does not require a gasket, and impurities due to inserting a gasket No mixing of particles and generation of particles.

[Brief description of drawings]

FIG. 1 is a front view showing a partial cross section of a first embodiment of the present invention.

FIG. 2 is a right side view showing a partial cross section of the first embodiment of the present invention.

FIG. 3 is a front view showing a partial cross section of a second embodiment of the present invention.

FIG. 4 is a right side view showing a partial cross section of a second embodiment of the present invention.

[Explanation of symbols]

 1: Female nut 3: Male screw member 5: Intermediate screw member 7: Female screw 9: Male screw 11: Male screw 13: Female screw 15, 17: Butt welding piece 19, 21: Collar 23: Press washer 25: Annular extension

Claims (6)

[Claims] 1. An intermediate screw member comprising a female nut, a tubular male screw member, and a large-pitch screw screwed into the screw of the female nut on the outer diameter, and a small-pitch screw screwed into the male screw on the inner diameter, A screw-in type pipe joint characterized in that the screw of the inner diameter and the screw of the outer diameter are processed in a forward screw relationship. 2. The female nut and the tubular male screw member of the pipe joint are engaged with the outer surface of the brim so as to press the pair of bridging tubular pieces having the mating surfaces lapped toward each other. 1 threaded pipe fitting. 3. A press washer is inserted between the female nut and the outer surface of one of the collars, and the outer peripheral surface of the press washer is engaged with the tip of the intermediate screw member in the closing direction. The screw-in type pipe joint according to claim 2. 4. A female nut, a male screw member, and an intermediate screw member having an outer diameter having a screw screwed into the screw of the female nut and an inner diameter having a screw screwed into the male screw. A screw-in type pipe joint characterized in that the screws are processed in reverse thread relation. 5. The female nut and the tubular male screw member of the pipe joint are engaged with the outer surface of the brim so as to press the pair of tubular pieces with flanges having the mating surfaces lapped toward each other. 4 threaded pipe fittings. 6. A press washer is inserted between the female nut and the outer surface of one of the collars, and an outer peripheral surface of the press washer is engaged with a tip of the intermediate screw member in a tightening direction. The screw-in type pipe joint according to claim 5.