JPH10252968A - Tube joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tube joint having a detachment preventive means by press-fitting a shape-keeping ring while expanding a part in the vicinity of an end part of a fluorocarbon resin tube, forming a tube expansion part, and tightening its inclined surface part to a joint body with cap nuts. SOLUTION: A cylindrical part 5 of a hard resin joint body 4 having an annular groove 3 is inserted in a shape-keeping ring 2 which is press-fitted to and positioned to an inner circumferential surface of an expanded part 1A of a tube 1, most of the tube expansion part 1A is inserted in the annular groove 3, and an inclined surface part 1a of the tube expansion part 1A is directed toward the shape-keeping ring 2 by a pressure ring 7 and tightened with hard cap nuts 6 screwed into a male screw part 4a of the joint body 4. An annular wedge 7a is inserted between the inclined surface part 1a and the outer circumferential surface of the annular groove to make a tube detachment preventive part. A tube bent part 1B is pressed against a tip of the cylindrical part 5 at a hole edge 6a of the cap nuts 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tube joint suitable as a joint for a fluororesin tube for controlling a flow path of a washing liquid such as pure water and other general chemicals used in a clean room at a high-density semiconductor chip manufacturing site or the like. About.

[0002]

2. Description of the Related Art Conventionally, as this type of tube joint,
For example, there is one disclosed in Japanese Utility Model Laid-Open No. 4-122882.

[0003] In this conventional technique, an outer flange and a large-diameter portion are formed at the end of a tube made of a fluororesin, and the large-diameter portion is formed in a tube joint in which a tube is formed to have a deformed portion to prevent the tube from coming off. The insertion cylinder of the joint body having a groove ring in the diameter portion was inserted, and most of the ring loosely inserted in the large diameter portion was inserted into the groove ring and screwed into the male screw portion of the joint body. The ring is tightly pressed against the outer flange with a cap nut to prevent the tube from slipping off, and the inner part of the shoulder of the cap nut presses the middle portion of the tube tightly to the end face of the insertion tube to bend the tube. This is a tube joint formed by:

[0004]

In the prior art, the step of a thermal operation for forming a deformed portion in a tube is required twice, which is time-consuming. The shape of the collar will not be even,
In some cases, imbalance occurs at the time of tightening, and stable tightening cannot be performed, and skill in heating is required.

Further, after the large diameter portion is formed, the tube bending portion gradually shrinks with time after the mold is removed, and the tube refraction portion does not sufficiently enter the insertion tube, so that heat remains in the large diameter portion. Since it has to be quickly pushed into the insertion tube of the joint, there are many problems that agile work is required.

[0006] In addition, as described in Japanese Utility Model Application Laid-Open No. 62-86489, a tapered enlarged portion is formed in a tube, a shape retaining ring is press-fitted inside the enlarged portion, and the inclined portion of the enlarged portion is inclined with a cap nut. Tube joints in which the tube is prevented from coming off by being fastened to the joint body at the portion are also well known. However, in this conventional example, since there is no means for fastening the joint refraction portion between the tube enlarged portion and the tube to the joint body, the tube or pipe is easily pulled out of the joint at a high temperature, and the joint has poor airtightness and liquid tightness. In particular, when the tube is made of a material having a large outer surface lubricity such as a fluororesin tube,
The tube often comes off, and the "nuts" of the cap nut over time also increase.

Further, during use at high temperatures, in this conventional example, the shape of the shape retaining ring or the tube is deformed by the heat cycle, and a slight liquid pool is generated between the inner surface of the tube and the outer surface of the shape retaining ring. Thus, there is a problem that so-called "dead water" is stored, or fine particles for polishing are caught and grown on the deformed portion and the diameter of the tube is reduced.

According to the present invention, in order to eliminate the above-mentioned problems, the enlarged tube portion inserted into the groove ring of the joint main body is tightened to the joint main body with a cap nut, so that the inclined portion of the tube enlarged portion is removed. A wedge ring of the press-contact ring is tightly inserted with a shape-retaining ring interposed between the groove and the inner peripheral surface of the groove ring to form a first tube retaining portion, and a tube bending portion connected to the tube enlarged portion is closed. By tightly pressing the tip of the cylindrical portion of the joint body with the edge of the hole of the nut, it becomes the second tube retaining portion and the airtight holding portion, and the cylinder of the joint body is inserted into the shape retaining ring press-fitted into the tube enlarged portion. An object of the present invention is to eliminate the dead water pool by separating the shape retaining ring and the fluid passage by the tubular portion by inserting the tubular portion.

[0009]

SUMMARY OF THE INVENTION It is an object of the present invention to increase the diameter of the vicinity of the end of a fluororesin tube while press-fitting a shape-retaining ring to form a tube enlarged-diameter portion, and to fill the slope with a bag. A hard resin joint body having a groove ring in a shape-retaining ring press-fitted on the inner peripheral surface of the enlarged diameter portion of the tube when forming a tube joint with a tube secured by tightening the nut with the joint body Insert the cylindrical portion of the tube, insert the majority of the tube enlarged portion into the groove ring, and expand the tube with a hard cap nut screwed into the external thread portion of the joint body outside the groove ring. By tightening the slope of the part toward the shape retaining ring with a pressure contact ring made of hard resin,
A wedge ring of the press contact ring is tightly inserted between the slope portion and the outer peripheral surface of the groove ring to serve as a first tube retaining portion, and a tube bending portion connected to the tube enlarged portion is a hole of a cap nut. This was achieved by forming the second tube retaining portion and the airtight holding portion by tightly pressing the edge of the tubular portion of the joint body at the edge. The press-contact ring may be fastened with a cap nut from the outside of a protruding ring protruding from its end.

[0010]

Embodiments of the present invention will be described with reference to the drawings. First, the basic form of the present invention is:
As shown in FIG. 1 to FIG.
A fluororesin shaped ring is formed by forcibly pressing the vicinity of the end of a fluororesin tube 1 such as fluoroethylene (PTFE) or PFA into a heated diameter-expanding jig A as shown in FIG. 2 as shown in FIGS. 2 (c) and 3 to form a tube enlarged-diameter portion 1A, and apply a pressing ring 7 to the slope 1a in the order shown in FIGS. As shown in FIG.
The tube joint according to the present invention has a basic form in which the tube is prevented from coming off by tightening as described above.

More specifically, the shape retaining ring 2 press-fitted and positioned on the inner peripheral surface of the enlarged diameter portion 1A of the tube 1 as shown in FIG.
As shown in FIG. 3, a tubular portion 5 of a joint body 4 made of a hard resin such as fluororesin or polypropylene having a groove ring 3 as shown in FIG. 3 is inserted as shown in FIG. Insert into ring 3. Next, as shown in FIGS. 4 and 5, a hard cap nut 6 made of a fluororesin or polypropylene screwed into the external thread portion 4a of the joint main body 4 outside the groove ring 3 as shown in FIGS. Part 1a
The pressing ring 7 made of a hard resin such as fluororesin or nylon 66 forcibly flexes the protruding ring 7A and tightens it toward the tight shape retaining ring 2 as shown in FIG.

The tightening stress is caused by the wedge ring 7a of the press contact ring 7 between the shape retaining ring 2 and the outer peripheral surface of the groove ring 3 as shown in FIG. The first tube retaining portion is formed by forcibly “clicking in” and sandwiching the slope portion 1a of the tube enlarged-diameter portion 1A tightly. At the same time, the tube bending portion 1B connected to the tube enlarged portion 1A is tightly pressed against the tip of the tubular portion 5 of the joint body 4 at the hole edge 6a formed at the cap nut 6 at an acute angle as shown in FIG. Thus, the tube joint of the present invention in which the retaining portion and the airtight holding portion of No. 2 were formed.

In the above example, the press ring 7 is forcibly pulled from the outside of the protrusion ring 7A projecting from the end of the press ring 7 and slightly bent by a strong external force as shown in each of the drawings. An example is shown in which the cap nut 6 is tightly tightened while being bent. When the cap nut 6 is slightly loosened as shown in FIG. 8 due to long-term use, the normal use form shown in FIG. 7 can be restored by retightening the cap nut 6.

The shape of the shape retaining ring 2 is shown in FIG.
As shown in FIG. 10, the shape retaining ring 2 with the outer flange 2a may be used as shown in FIG. 10, and in this example, the distal end of the tube enlarged-diameter portion 1A comes into contact with the outer flange 2a, so that the The position of the press-fit into the enlarged diameter portion 1A can be determined, which is suitable for mass production. Further, as a form of the pressure contact ring 7, as shown in FIG.
The ring may have a simple wedge-shaped cross section, and may be used as a press-contact ring in which the protruding ring 7A of the previous example is omitted.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The material of each of the above-mentioned components can be appropriately determined according to the type of fluid flowing through the tube 1 and the joint main body 4. If members other than 1 are made of a tough material such as metal, the strength will be increased. Further, when the operation is performed under severe use conditions such as a semiconductor chip manufacturing site, all of the constituent members including the tube 1 are replaced with P
By making with fluororesin like TFE or PFA,
This was sufficient as a flow path of a cleaning liquid for a semiconductor chip at the time of manufacturing a high-density VLSI (large-scale integrated circuit) chip.

[0016]

The present invention adopts the above-described embodiment, and has the following effects. The tube enlarged-diameter portion 1A inserted into the groove ring 3 of the joint main body 4 is tightly tightened to the joint main body 4 with the cap nut 6 to thereby form the tube enlarged-diameter portion 1A.
A wedge ring 7a of the press-contact ring 7 is tightly inserted between the slope portion 1a of A and the outer peripheral surface of the groove ring 3a to form a first tube retaining portion, and a tube bending portion connected to the tube enlarged portion 1A. The portion 1B is tightly pressed against the tip of the tubular portion 5 of the joint body 4 by the hole edge 6a of the cap nut 6 to form a second tube retaining portion and an airtight holding portion. Strictly airtight and liquid tight,
The first effect is that it is tightly connected to the joint body 4 and does not loosen or pull out unnecessarily, and can be used safely for a long period of time.

In particular, in the present invention, the tube enlarged portion 1
The cylindrical portion 5 of the joint body 4 is inserted into the shape-retaining ring 2 press-fitted in A.
Is inserted, so that the shape retaining ring 2 and the fluid passage are separated from each other by the cylindrical portion 5 so that dead water pools can be eliminated, and the retaining strength of the first tube retaining portion can be increased. There is also a second effect that is achieved.

According to the second aspect of the present invention, the press-contact ring 7 is capable of forcibly slightly bending its protruding ring 7A and tightening it with the cap nut 6 to the joint body side. Even if some variation occurs, the tube bending portion 1
B at the end of the cylindrical portion 5 of the joint body 4
The effect of (a) can be firmly applied, and a high degree of airtightness and enhancement of retaining can be promoted.

[Brief description of the drawings]

FIG. 1 is an enlarged longitudinal sectional side view showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing an example of forming a tube enlarged diameter portion in the present invention.

FIG. 3 is a longitudinal sectional side view showing an example of a tube joint according to the present invention during assembly;

FIG. 4 is a longitudinal sectional side view showing an example of a tube joint according to the present invention during assembly.

FIG. 5 is a longitudinal sectional side view showing one example of a tube joint according to the present invention during assembly.

FIG. 6 is a vertical sectional side view showing an example of a tube joint according to the present invention during assembly.

FIG. 7 is a longitudinal side view showing an example of an assembled product of a tube joint according to the present invention.

FIG. 8 is a longitudinal sectional side view showing an example of a state before retightening the tube joint according to the present invention.

FIG. 9 is a longitudinal sectional side view showing an example of an assembling process according to another embodiment of the present invention.

FIG. 10 is a longitudinal sectional side view showing an example after completion of assembling showing another embodiment of the present invention.

FIG. 11 is a longitudinal sectional side view showing an example after completion of assembling showing still another example of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Tube 1A Tube expansion part 1B Tube bending part 1a Bevel part 2 Shape retaining ring 3 Groove ring 4 Joint body 4a Male screw part 5 Cylindrical part 6 Cap nut 6a Hole edge 7 Press-contact ring 7A Projection ring

Claims (1)

[Claims] 1. The tube is prevented from coming off by press-fitting a shape-retaining ring while expanding the diameter in the vicinity of the end of the fluororesin tube, forming a tube enlarged-diameter portion, and tightening the slope portion of the tube to a joint body with a cap nut. Of the rigid resin joint body 4 having a groove ring 3 in a shape retaining ring 2 press-fitted and positioned on the inner peripheral surface of the enlarged diameter portion 1A of the tube 1.
Is inserted into the groove ring 3, and the tube is expanded with a hard cap nut 6 screwed into the external thread portion 4 a of the joint body 4 outside the groove ring. The inclined portion 1a of the diameter portion 1A is fixed to a pressure contact ring 7 made of hard resin.
The pressing ring 7 between the inclined surface 1a and the outer peripheral surface of the groove ring 3a.
The wedge ring 7a is tightly inserted into the first tube retaining portion, and the tube bending portion 1B connected to the tube enlarged portion 1A is connected to the tip of the cylindrical portion 5 of the joint body 4 by the hole edge 6a of the cap nut 6. A tube joint in which a second tube stopper portion and an airtight holding portion are formed by tight pressure contact. 1. The tube joint according to claim 1, wherein the press-contact ring is fastened with a cap nut from the outside of a protruding ring provided at an end thereof.