JPS61160692A - Mechanical joint - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to mechanical joints, and particularly to an annular type flexible stainless steel pipe joint used as indoor piping for gas and water.

(Prior art and problems) In recent years, for example, "Gas Association Magazine" March 1983 issue 26
As seen in "Piping Technology J, July 1980 issue, pages 106 to 111," flexible tubes are increasingly being used for gas and water piping. - Compared to piping work that uses threaded connections with tees, piping work that takes advantage of the characteristics of flexible tubes requires no thread cutting, and therefore fewer joints, resulting in fewer leakage points, and piping work that takes advantage of the characteristics of flexible tubes. It has the advantages of low cost and excellent safety.

Due to its intended use, flexible tube fittings are required not only to have excellent airtightness, but also to be easy to assemble on-site depending on the length of the piping. In order to meet such demands, conventional methods such as
As a joint for a flexible tube seen in Japanese Patent No. 142622, as shown in FIG. There is a joint that secures airtightness by sandwiching 8, but when tightening, there is a risk of leakage due to damage to the flexible tube due to excessive tightening, and the position of the design is such that it is tightened with the base fitting free. difficult to place.

Furthermore, when an excessive bending load is applied to the flexible tube 7, the sealing surface composed of the connector body 4, the armrest 8, and the end of the flexible tube 1 may shift, causing a risk of leakage. There are drawbacks such as.

(Means for Solving the Problem) Therefore, the present inventors have developed an annular tube that does not impair the flexibility, which is the original function of flexible tubes, that is, does not deteriorate the leakage property even if the piping is subjected to severe bending. As a result of various studies in order to provide a mechanical joint for flexible tubes for
The present invention was made based on the completely new knowledge that the above-mentioned problems can be solved all at once by providing a sealing surface with a metal-to-metal contact surface.

(Structure and operation of the invention) That is, the present invention provides a joint constructed of a flexible tube, a locking ring, a cap nut, and a connector, in which the male thread of the connector is mated with the female thread of the cap. A lip portion is provided at the distal end, and has a shoulder surface with which the end of the flexible tube collides to form a sealing surface, and a lip portion with a tapered surface that comes into close contact with the outermost circumferential surface of the seven flexiple tubes. A mechanical joint characterized in that the lip portion and the flexible tube constitute two metal-to-metal sealing surfaces due to a compressive force generated through the locking ring mounted several threads apart from the end. be.

Next, the present invention will be described in detail based on the drawings. Figure 1 shows one embodiment of the joint of the present invention, and is a sectional view of the entire joint in a state where the tightening is completed. A locking ring 2 is attached to the flexible tube 1, and the locking ring 2 is fitted into a bag 3. The cap nut 3 is screwed to the connector 4. A lip portion 5 is provided at the tip of the screw of the connector 4. A shoulder surface 6 is provided on the inner surface of the lip portion 5.
and a tapered surface 7, so that the end of the flexible tube 1 is likely to fit into the taper portion 5. α represents the angle formed between the surface 7 of the chi 1' of the lip portion 5 and the tube axis direction, and β represents the angle formed between the shoulder surface and the tube axis.

To form the joint, first, the bag 3 is attached to the flexible tube 1, and then the locking ring 2 is attached and the tube is inserted into the lip portion 6 of the connector 4.

From this state, by screwing and tightening the cap nut 3 and connector 4, the flexible tube 1 at the tip of the locking ring 2 is compressed in the tube axis direction, and as shown in FIG. Deformed into a square shape, the eight end portions of the flexible tube 1 abut against the shoulder surface 6 to form a tightly sealed metal-to-metal first sealing surface. The outermost diameter part of the tip of the 7 lexi-pulch, which is further compressed and deformed into a U-shape, expands, and the f part 5
2 and 7 to form a second metal-to-metal sealing surface.

The tip of the flexible tube 1, which has been deformed into a U-shape, is restrained by the lip portion 5 in both the axial and radial directions, and is subjected to severe damage to the flexible tube 1 exposed from the cap nut 3. Even if a bending load is applied, the surface pressure of the sealing surface is not impaired in the slightest.

In order to ensure the airtightness of the metal-to-metal sealing surface, the sealing surface of the f section 5 should be plated with soft copper or zinc. In order to deal with the uneven cutting edges, it is possible to adopt a structure in which a copper packing or gasket is inserted between the shoulder surface 6 and the flexible tube 1.

Further, the tip of the grooved portion 5 is formed so as to collide with the locking ring 2 by tightening the screw K.

This works to appropriately control the amount of compression in the axial direction at the tip of the 7 lexi pull tube 1, and is composed of the shoulder surface 6 that occurs when the amount of axial compression is small and the tip surface of the 7 lexi pull tube 21. This prevents the deterioration of the airtightness of the sealing surface due to the large amount of compression in the axial direction, and also prevents cracking, that is, deterioration of the airtightness, due to excessive plastic deformation of the outermost or innermost periphery of the 7 lexiple tube 1, which occurs when the amount of compression in the axial direction is large. do the work. In this case, the reason why the locking ring 2 is installed separately from the end of the flexible tube 1 is to widen the control range of the compression amount, and to connect the outermost circumferential surface of the tip of the flexible tube 1 to the lip portion 5. This is to ensure better airtightness by increasing the number of sealing surfaces formed by the tapered surface 7.

Note that the dispersion referred to here depends on the dimensions of 7 lexipulch, -2, but if it is about 3 to 5 peaks, it is sufficient to achieve the intended purpose. Furthermore, the reason for setting the angle α between the chi 2 surface 5 and the tube axis direction is as follows:
This contributes to centering performance when inserting the flexible latch 1 into the lip portion 5, and also contributes to preventing unstable deformation (buckling) that occurs when the tip of the flexible latch 1 is compressed by screw tightening. It is. Note that the appropriate size of the angle α is about 3° to 5°.

On the other hand, as shown in FIG. 1, the lip portion 5 has a sill surface 6 that is inclined at an angle β with the tube axis. , - enables the positioning of the tip of the flexible nap 1, prevents displacement of the contact surface between the shoulder surface 6 and the three parts of the tip of the flexible nap 1, and forms an excellent sealing surface.

Note that the appropriate size of the angle I is about 3° to 10°.

The effects of the present invention will be illustrated in more detail with reference to Examples below.

(Example) Ani, Lartaiso 7 lexiple tube, maximum outer diameter 2
5.4 tm, minimum inner diameter 19n, wave height 3 tn, average plate thickness 0.5 m, pitch 2.5 tm, outer diameter 30
m s inner diameter 20 wx, width 3, inner radius 1.
Attach a 5fi locking ring to the groove between the 4th and 5th ridges from the end of the flexible latch, outer diameter 30u, lip length 4u, end thickness 2m+, (!-3 ', βm 3
Q@, shi.

The connector has a glue part with a glue thickness of approximately 18 mg.
As a result of various performance evaluations of the joint parts of the mechanical joint of the present invention tightened with M32 screws, and a comparison joint without the f part, a pressure resistance test was performed in which water pressure of 10 kgf/- was applied for 1 minute. , 9 bags were tested for airtightness by applying an air pressure of 3 kgf/- for 1 minute.

After applying an impact force of 9f to 210 to the
In an impact test in which an air pressure of /j was applied for 1 minute, all of the joints of the present invention were perfect without leaking. All comparison fittings leaked.

In addition, it was used as a gas pipe for Ar gas lo kit/d, but a leak test using a soap and water test revealed no abnormalities.
The joint according to the present invention has practically excellent airtightness and is extremely useful industrially.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of essential parts showing one aspect of the threaded joint of the present invention, and FIG. 2 is a sectional view showing the structure of a conventional threaded joint. 1.-Flexible latch, -f, 2-.Latching ring, 3
- Cap nut, 4 - Connector, 5 - Lip part, 6... Shoulder of lip part,
7...14 sides of the lip part, 8...Putskin, α.
...The angle between the taper surface and the tube axis, β...The angle between the shoulder surface and the tube axis. Figure 1 Figure 2 Procedural amendments - February 1939, Director General of the Japan Patent Office 17 ”Indication of the case Showa 10 Patent Application No. 1]] Relationship with Case No. 1 Application , Address (Residence) Higashifu [Miyakochiyo r!-11-<Kate Knee-cho 2-chome 16-3 (Agent address: 330 Marunouchi Shigesu Building, 2-6-2 Marunouchi, Chiyoda-ku, Tokyo) Date of order White fan ≦″ Amendment The following matters in the specification of the application will be amended. In the bottom line of pages 1 and 2, “Figure 1” will be corrected to “Figure 2.” Page 8 of 2 Line 12 says "about 3° to 1♂". Correct it to "about 80° to 87°." 3. Page 9, line 3 says "β=30°". "β=80' Correct it as J. 4. On page 9, line 4, it says "thickness is about 18cm". Correct it as "approx. 3m thick." 5. Page 9, lines 8, 9, 10 rI on line and 14th line
The words ``K9f/■2'' are corrected to ``r kgf/儒2'' respectively. 6. Page 9, bottom line, page 10, line 1 K: Correct the words ``threaded joints'' to ``mechanical joints.''

Claims (1)

[Claims] In a joint composed of a flexible tube, a locking ring, a cap nut, and a connector, at the tip of the male thread of the connector that couples with the female thread of the cap nut,
a lip portion having a shoulder surface with which the end portion of the flexible tube comes into contact to form a sealing surface and a tapered surface that comes into close contact with the outermost peripheral surface of the flexible tube;
The lip portion and the flexible tube form two metal-to-metal sealing surfaces due to the compressive force generated through the locking ring, which is mounted several threads apart from the end of the flexible tube by tightening the screws. A mechanical joint characterized by: