JP2002156083A - Joint for flexible tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a joint for a flexible tube capable of detecting the occurrence of gas leakage by driving a nail and formed using a novel selected permeation member. SOLUTION: This joint is for the flexible tube 1 constituted by covering a corrugate pipe 2 with a covering body 3 made of resin. A packing 30 capable of preventing the entry of foreign matter such as water into the joint 10 and letting gas entering the inside of the joint 10 through a clearance between the covering body 3 and the corrugate pipe 2 after leaking from the corrugate pipe 2 of the flexible tube 1 escape outside of the joint 10 is provided. This packing 30 is formed of nonwoven fabric formed by ceramic fibers.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a joint for a flexible tube used for a gas pipe.

[0002]

2. Description of the Related Art As a joint for a flexible tube used for a gas pipe, for example, there is one disclosed in Japanese Patent Application Laid-Open No. 9-166256.

[0003] The flexible tube used for this joint has a structure in which a corrugated tube is covered with a resin coating, and is connected to other members such as gas appliances using this joint.

[0004] When constructing a house provided with gas piping using such a flexible tube and a joint, nailing work is often performed after piping of the flexible tube. At this time, if the tip of the nail reaches the flexible tube by mistake, the nail breaks through the corrugated tube and gas leaks at that portion. On the other hand, since the resin cover is closely attached to the periphery of the nail, no gas leaks from this portion to the outside. For this reason,
The gas leaked from the corrugated pipe flows into the inside of the joint through the gap between the corrugated pipe and the covering, and flows out of the joint through a through-hole-shaped air passage formed in the joint. As a result, it is possible to find out the occurrence of gas leakage due to nailing and take appropriate measures.

[0005] The through-hole is closed by a permselective member that permits the passage of gas from the inside to the outside of the joint, but prevents permeation and intrusion of water and dust from the outside into the joint. The permselective member is formed of a porous body having continuous pores molded from a thermoplastic resin powder.

[0006]

SUMMARY OF THE INVENTION The present invention is to provide a joint for a flexible tube which can detect the occurrence of gas leakage due to such nailing, and to obtain a joint using a novel selective permeation member. The purpose is to be able to.

[0007]

SUMMARY OF THE INVENTION In order to achieve this object, the present invention relates to a joint for a flexible tube having a structure in which a corrugate tube is covered with a resin coating. Gasket that can prevent gas from entering the joint through the gap between the sheath and the corrugate tube after leaking from the corrugate tube of the flexible tube and that can escape outside the joint. The packing is constituted by a non-woven fabric formed of ceramic fibers.

[0008] With such a structure, the packing for releasing gas leaked from the corrugated pipe of the flexible tube and then entering the joint through the gap between the covering body and the corrugated pipe to the outside of the joint, A joint for a flexible tube having a novel packing made of a nonwoven fabric formed of ceramic fibers is obtained. This packing prevents permeation and intrusion of water and dust into the joint.

According to the present invention, there is provided a joint for a flexible tube having a structure in which a corrugated pipe is covered with a resin-made cover, a tubular body, and a snap ring having a tip portion screwed into the tubular body. And, provided between the tubular body and the retaining ring, it is possible to prevent foreign matter such as water from entering the joint, and after leaking from the corrugated tube of the flexible tube, the covering body and the corrugated tube And a gasket that allows the gas that has entered the joint through the gap to escape to the outside of the joint. The gasket is formed of a nonwoven fabric made of ceramic fibers.

[0010] The present invention also provides a joint for a flexible tube having a structure in which a corrugated tube is covered with a resin coating, a tubular body, and a snap ring having a distal end screwed into the tubular body. And a through-hole formed in at least one of the tubular body and the retaining ring to communicate between the inside of the tubular body and / or the retaining ring and the outside thereof, and provided in a state in which the through-hole is closed. It is possible to prevent the intrusion of foreign substances such as water into the joint through the through hole, and to leak from the corrugated tube of the flexible tube and pass through the gap between the covering body and the corrugated tube to the through hole. And a packing capable of allowing gas that has entered into the joint to escape from the joint, wherein the packing is constituted by a nonwoven fabric formed of ceramic fibers.

The present invention also provides a joint for a flexible tube having a structure in which a corrugated pipe is covered with a resin covering, a tubular body, and a snap ring having a distal end screwed into the tubular body. And a retainer provided near the distal end of the retaining ring inside the cylindrical main body, wherein the flexible tube is configured such that the distal end of the corrugated tube from which the coating is removed is a retaining ring, a retainer, and a cylindrical member. Inserted into the joint between the end face of the base end of the retaining ring and the end face of the cylindrical body, the tip of which is screwed into the inside of the cylindrical body, with the tip part screwed into the inside of the cylindrical body. It is possible to prevent the intrusion of foreign substances such as water and the like, and it is possible to escape the gas that has entered the joint through the gap between the sheath and the corrugate pipe after leaking from the corrugated pipe of the flexible tube to the outside of the joint. Pack There is mounted, the packing are those as are constituted by a nonwoven fabric formed by ceramic fibers.

According to the present invention, the ceramic fibers constituting the packing can contain silica and alumina. Further, according to the present invention, the nonwoven fabric forming the packing can be a mixture of ceramic fibers and pulp.

Further, according to the present invention, the nonwoven fabric constituting the packing can be made by papermaking. Further, according to the present invention, the packing can be subjected to a water-repellent treatment.

Further, according to the present invention, the packing can be subjected to the water repellent treatment not only on the surface thereof but also on the inside thereof. Also according to the present invention,
It is preferable to add a water-repellent agent to the suspension containing the ceramic fibers during the papermaking of the packing non-woven fabric.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, reference numeral 1 denotes a flexible tube, which is a thin stainless steel corrugated tube 2;
The corrugated tube 2 is made up of a resin-made tubular covering 3 covering the outer periphery of the corrugated tube 2. In the corrugated tube 2, reference numeral 4 denotes a peak, and 5 denotes a valley. This flexible tube 1 has a joint 1 according to the present invention in a state in which the coating 3 is removed at several peaks of the corrugated tube 2.
Connected to 0.

In this joint 10, reference numeral 11 denotes a cylindrical main body, which is formed of metal such as brass, and has an external thread 12 formed at one end thereof, so that it can be connected to a connected body such as a gas pipe. It is configured as follows. A hexagonal portion 13 is used for screwing the outer thread portion 12. 14 is an end surface on the other end side.

On the inner periphery of the cylindrical main body 11, in order from the opening side at the other end, an inner thread portion 15 and an inner thread portion having a diameter equal to or slightly larger than the inner diameter of the thread root of the inner thread portion 15. A peripheral surface 16 and an annular sealing material housing 17 having a smaller diameter than the inner peripheral surface 16 are formed. An annular rubber sealing material 21 is loosely press-fitted in the sealing material housing 17.

In the joint 10, reference numeral 25 denotes a retaining ring, which is formed in a tubular shape by a metal such as brass, and has an outer thread portion 26 which can be screwed into the inner thread portion 15 of the tubular main body 11 at one end thereof. . A circumferential outer peripheral surface 27 is formed on the outer circumference on the other end side of the retaining ring 25. The outer peripheral surface 27 is formed to have a larger diameter than the outer thread portion 26, and thus an end surface 28 facing the end surface 14 of the tubular main body 11 is formed. An annular packing 30 is attached to a portion on the base end side of the end surface 28 of the retaining ring 25. This packing 30
Is compressed between the end surface 28 of the retaining ring 25 and the end surface 14 of the cylindrical body 11 when the retaining ring 25 is screwed into the cylindrical main body 11.

The retaining ring 25 has a hole 31 through which the flexible tube 1 is inserted. A tapered surface 37 is formed on the inner periphery of the rear end of the retaining ring 25, which is located on the inner side of the hole 31. The tapered surface 37 increases in diameter toward the rear end of the retaining ring 25. As shown, when the retaining ring 25 is completely screwed into the cylindrical main body 11, the tapered surface 37 on the inner periphery of the retaining ring 25, the inner peripheral surface 16 of the cylindrical main body 11, and the end surface of the sealing material 21 are combined. An enclosed space 39 is formed. In this space 39, an annular retainer 40 is arranged.

The retainer 40 is formed of a metal material such as brass, and has a radially inwardly protruding projection 43 provided at an inner periphery of a tip thereof along a circumferential direction. The projection 43 has an inner diameter of the corrugated tube 2.
Are formed so as to have a size smaller than the outer diameter of the valley portion 4 and equal to or greater than the outer diameter of the valley portion 5, and can enter the valley portion 5. The retaining ring 2 is provided on the outer periphery of the retainer 40.
An outer peripheral tapered surface 44 having the same inclination as the tapered surface 37 of No. 5 is formed.

As shown in FIG. 1 and FIG.
Numeral 0 is constituted by a ring-shaped nonwoven fabric formed of ceramic fibers. For example, a first ceramic fiber formed of silica and a second ceramic fiber formed of alumina are mixed, and further a paper is formed by a wet method in a state where an acrylic binder is mixed with the first ceramic fiber. It is formed by doing. Further, for example, the fiber diameter is about 3 μm, and the basis weight is 110 to 120 g / m.
^2. Density: 0.18 to 0.20 g / m ³ , air permeability: 0.1
Preferably, it is on the order of seconds / cc.

In the packing 30, the above-mentioned acrylic binder itself has water repellency, and is subjected to a water repellency treatment with, for example, a silicon-based water repellent. This water repellency treatment can be performed by forming a nonwoven fabric forming the packing 30 and then applying a water repellent to the surface thereof. Alternatively, when a nonwoven fabric is formed by a wet method, a water repellent treatment can be performed by adding a water repellent to a suspension containing ceramic fibers and a binder. As described above, according to the method of adding a water-repellent agent during papermaking, a state in which the water-repellent agent is sufficiently penetrated into the inside of the packing 30 as compared with a case where the water-repellent agent is applied to the surface of the packing 30. That is, since the packing 30 is molded in a state where the water repellent is attached to the entire constituent fibers of the nonwoven fabric forming the packing 30, a remarkable water repelling effect can be expected.

For example, in the case where the annular packing 30 is formed by punching a sheet-like nonwoven fabric, if a water-repellent agent is applied to the surface of the sheet-like nonwoven fabric, the punching process is performed. Packing 30
The inner peripheral end face and the outer peripheral end face are in a state where the water repellent is not applied. On the other hand, when a water-repellent agent is added during papermaking, the water-repellent agent adheres to the entire constituent fibers of the nonwoven fabric as described above. When forming the annular packing 30 by applying the same, it is possible to mold the annular packing 30 in which the water repellent is present on the inner peripheral end face and the outer peripheral end face.

The packing 30 is compressed so as to have a thickness of 50 to 80% between the retaining ring 25 and the cylindrical main body 11. As a result, the packing 30 is in a state in which dust and water cannot pass but gas can pass. In addition, a water-repellent agent can be applied to a corresponding portion between the retaining ring 25 and the tubular main body 11 in order to further improve the performance of blocking water.

The non-woven fabric forming the packing 30 has a structure using ceramic fibers formed of silica or alumina as described above, but has a structure in which pulp is further mixed with the ceramic fibers. Is preferred. Pulp exhibits excellent elasticity as compared with ceramic fibers, so that the mechanical strength of the packing 30 can be improved by mixing the fibers. Further, the packing 30 in which the pulp having elasticity is mixed has good compressibility, and therefore, as described above, the retaining ring 25 and the tubular main body 1 are combined.
1 can be reliably compressed to a predetermined thickness of 50 to 80%, and an effect of improving the sealing property can be expected.

The compression of the packing 30 by screwing the retaining ring 25 into the cylindrical main body 11 is performed at a manufacturing plant of the joint 10. That is, in this manufacturing plant, the retaining ring 25
When screwing into the cylindrical body 11, the outer circumferential surface 2 of the retaining ring 25
Since 7 has a columnar shape, the outer peripheral surface 27 is gripped by a chuck or the like, screwed in, and tightened with a predetermined torque. Since the tightening is performed in the manufacturing factory as described above, the tightening torque can be easily managed so as to have an appropriate constant value. When the tightening torque of the retaining ring 25 to the tubular main body 11 is constant, the compression of the packing 30 has a thickness of 50%.
It can be easily controlled so as to have an appropriate value of ８０80%. As a result, further compression can be prevented, and it is possible to reliably prevent the required sealing performance, particularly the performance of passing gas, from being affected.

In such a case, when the flexible tube 1 is joined to the joint 10, as shown in the figure, the flexible tube 1 is cut at the valleys of the corrugated pipe 2 and is covered at several peaks, for example, six peaks at the tip of the corrugated pipe 2. The flexible tube 1 with the body 3 removed is inserted into the hole 31 from the end of the retaining ring 25. Then, the ridge 4 at the tip of the corrugated tube 2 pushes and expands the retainer 40 and passes through the inner periphery of the protrusion 43. Similarly, when several peaks at the tip of the corrugated pipe 2 pass through the projection 43 of the retainer 40, several peaks at the tip of the corrugated pipe 2 are removed from the sealing material 2 as shown in FIG.
Go inside 1 At this time, the retainer 44 has returned to the original reduced diameter state due to elasticity, and the protrusion 43 is engaged with one of the valleys 5 of the corrugate tube 2. At this time, the corrugated pipe 2 enters the inner periphery of the sealing material 21 to exhibit a required sealing function.

FIG. 1 shows a state in which the operation of joining the corrugated tube 2 of the flexible tube 1 to the joint 10 has been completed. In the case of constructing a house provided with gas piping using the flexible tube 1 to which the joint 10 is joined as described above, when the tip of the nail reaches the flexible tube 1 by mistake during nailing work,
Gas leaked from the corrugated pipe 2
It flows into the inside of the joint through the gap between the cover and the cover 3, and reaches the packing 30 through the gap between the various parts.

At this time, since the gas passes through the packing 30 as described above, gas leakage from the packing 30 to the outside occurs. Therefore, it is determined that gas leakage due to nailing has occurred immediately after the nailing operation. Can be found in For this reason, during the construction of the house, that is, during the construction stage where the house is not yet completed, it is possible to detect the occurrence of gas leakage at an early stage and take appropriate measures.

When a pull-out force acts on the flexible tube 1 joined to the joint 10, the outer peripheral tapered surface of the retainer 40 in which the projection 43 engages with one valley 5 of the corrugated tube 2 as shown in the figure. 44 contacts the tapered surface 37 of the retaining ring 25, and the retainer 40 receives a radially inward reaction force from the retaining ring 25. Then, the protrusion 43 of the retainer 40
Presses the outer circumference of one valley 5 of the corrugated pipe 2 over the entire circumference, so that the engagement between the retainer 40 and the corrugated pipe 2 is ensured. Is reliably prevented from coming off.

FIG. 3 shows a joint for a flexible tube according to another embodiment of the present invention. Here, a packing accommodation groove 32 is formed on the end face 28 of the retaining ring 25, and the annular packing 30 shown in FIG. 2 is accommodated in the packing accommodation groove 32. A radial end face 33 and a radial projection 34 for forming the end face 33 are formed between the accommodation groove 32 and the external thread portion 26. The end surface 33 is the retaining ring 2
When the screw 5 is screwed into the cylindrical body 11, it comes into contact with the end face 35 of the inner threaded portion 15 of the cylindrical body 11 as shown in the figure, and thereby the packing 3 between the cylindrical body 11 and the snap ring 25 is formed.
The compression of 0 is set to an appropriate value of 70 to 80% of its thickness.

Since the packing 30 is housed in the housing groove 32 in this manner, it is prevented from escaping radially outward during compression. Also, since the protrusion 34 is formed,
The packing 30 accommodated in the accommodation groove 32 is
Is prevented from dropping off from the outer screw portion 26.

FIGS. 4 and 5 show a joint for a flexible tube according to still another embodiment of the present invention. Here, a retainer 52 is rotatably attached to the tip of the retaining ring 51, and the retaining ring 5 is attached to the cylindrical main body 11 as shown in FIG.
4 is pushed in deeper than the retainer 52 with the screw 1 loosely screwed in, and then the retaining ring 51 is rotated to rotate the retainer 52 and the cylindrical body 11 as shown in FIG. Of the corrugate tube 2 is crushed between the inner end surface 53 and the rear end surface 53 of the corrugated tube 2. Then, the space between the tubular main body 11 and the corrugated tube 2 is thereby sealed. At this time, the same sealing is performed by pressing the corrugated tube 2 against the O-ring 54. In addition, when several ridges at the tip of the corrugated pipe 2 are crushed in this way, at the same time, the end face 14 of the cylindrical main body 11 and the retaining ring 5 are crushed.
The annular packing 30 shown in FIG. 2 is compressed between the end face 55 and the first end face 55.

FIG. 4 shows the state at this time. By crushing several ridges at the tip of the corrugated tube 2 by the retainer 52 in this way, the crushed portion of the corrugated tube 2 and the retainer 52 engage each other, thereby preventing the flexible tube 1 from coming out of the joint 10. You.

FIG. 6 shows a joint for a flexible tube according to still another embodiment of the present invention. Here, the retaining ring 5
1, the outer periphery of the cover 3 is sealed by a seal material 61, and a radially through-hole-shaped ventilation path 62 communicating between the inside and the outside of the retaining ring 51 is formed in a portion deeper than the seal material 61. Is provided. An end portion of the ventilation ring 62 on the outer surface side of the retaining ring 51 is formed as a large-diameter portion 63, and the disc-shaped packing 30 is provided on the large-diameter portion 63.
Is loaded. The packing 30 is similarly formed of ceramic fiber, is press-fitted into the enlarged diameter portion 63, and has a peripheral surface adhered to an inner peripheral surface of the enlarged diameter portion 63 by an adhesive. The end portion 64 of the tubular main body 11 and the retaining ring 5
The space between the first end 65 and the first end 65 is sealed by a packing 66 such as an O-ring.

According to such a configuration, similarly, it is possible to prevent foreign matter such as water from entering the inside of the joint 10 by the packing 30, and to prevent the gas which has leaked out of the corrugate pipe 2 and then enters the inside of the joint 10. Can escape from the joint.

The through-hole-shaped ventilation path 62 provided with the packing 30 is provided in the cylindrical main body 1 instead of the retaining ring 51.
1 or both the retaining ring 51 and the tubular main body 11. In addition, as shown in the figure, not only a joint that crushes several peaks at the tip of the corrugated pipe 2 but also a so-called one-touch joint type joint as shown in FIG. Can also be provided.

[0038]

As described above, according to the present invention, it is possible to prevent foreign matter such as water from entering the joint in a joint for a flexible tube having a structure in which a corrugated tube is covered with a resin coating. A gasket that leaks out of the joint through the gap between the sheath and the corrugate pipe after leaking from the corrugate pipe of the flexible tube is provided, and the packing is made of ceramic. A flexible tube joint comprising a novel packing made of a nonwoven fabric formed of ceramic fibers and configured to cause gas leakage because it is constituted by a nonwoven fabric formed of fibers. Can be obtained.

[Brief description of the drawings]

FIG. 1 is a view showing a joint for a flexible tube according to an embodiment of the present invention.

FIG. 2 is a perspective view of a packing in FIG.

FIG. 3 is a view showing a flexible tube joint according to another embodiment of the present invention.

FIG. 4 is a view showing a joint for a flexible tube according to still another embodiment of the present invention.

5 is a sectional view of a main part showing a state before assembling the joint for a flexible tube of FIG. 4;

FIG. 6 is a view showing a joint for a flexible tube according to still another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Flexible tube 2 Corrugated tube 3 Coating body 10 Coupling 11 Cylindrical main body 14 End surface 25 Retaining ring 28 End surface 30 Packing

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hisao Onishi 4-1-2, Hirano-cho, Chuo-ku, Osaka-shi, Osaka Inside Osaka Gas Co., Ltd. (72) Inventor Toshio Shibuchi 2 Minamikagaya, Suminoe-ku, Osaka-shi, Osaka Chome 10-16 Shinwa Sangyo Co., Ltd. (72) Inventor Mikio Nakaoka 2-10-16 Minamikagaya, Suminoe-ku, Osaka-shi, Osaka Shinwa Sangyo Co., Ltd. (72) Inventor Kazuyoshi Karaki Suminoe, Osaka-shi, Osaka 2-10-16 Minamikagaya-ku Shinwa Sangyo Co., Ltd. F-term (reference) 3H017 CA07 CA11 3J040 AA01 AA12 BA01 EA16 FA13 HA15

Claims (10)

[Claims] 1. A joint for a flexible tube having a structure in which a corrugated tube is covered with a resin coating, wherein it is possible to prevent foreign matter such as water from entering the joint, A packing is provided that allows gas that has leaked out of the corrugate pipe and that has entered the joint through the gap between the coating and the corrugate pipe to escape to the outside of the joint, and the packing is a nonwoven fabric formed of ceramic fibers. A flexible tube joint characterized by being constituted by: 2. A joint for a flexible tube having a structure in which a corrugated pipe is covered with a resin coating, comprising: a tubular main body; and a retaining ring having a distal end screwed into the tubular main body. It is provided between the tubular body and the retaining ring to prevent foreign matter such as water from entering the joint, and to prevent the cover and the corrugated pipe from leaking from the corrugated pipe of the flexible tube. A packing capable of allowing gas that has entered the joint through the gap to escape to the outside of the joint, wherein the packing is made of a non-woven fabric formed of ceramic fibers. Fittings. 3. A joint for a flexible tube having a structure in which a corrugated tube is covered with a resin coating, comprising: a tubular main body; and a retaining ring having a tip portion screwed into the tubular main body. A through-hole formed in at least one of the tubular body and the retaining ring to communicate between the inside of the tubular body and / or the retaining ring and the outside thereof, and provided with the through-hole closed. Thus, it is possible to prevent foreign matter such as water from entering the joint through the through hole,
A gasket that leaks out of the joint through the gap between the sheath and the corrugate tube after leaking from the corrugate tube of the flexible tube, and a gasket that can escape out of the joint; A joint for a flexible tube, which is constituted by a formed nonwoven fabric. 4. A joint for a flexible tube having a structure in which a corrugated tube is covered with a resin coating, comprising: a tubular main body; and a retaining ring having a distal end screwed into the tubular main body. And a retainer provided in the interior of the tubular body near the distal end of the retaining ring, wherein the flexible tube is configured such that the distal end of the corrugated tube from which the coating has been removed has a retaining ring, a retainer, and a cylindrical body. Between the base end of the retaining ring and the end of the tubular body whose tip is screwed into the inside of the tubular body. Gasket that can prevent intrusion of foreign matter such as the like, and can escape gas that has leaked from the corrugated tube of the flexible tube and that has entered the joint through the gap between the sheath and the corrugated tube after the leakage. Is installed The packing fitting for a flexible tube, characterized in that it is constituted by a nonwoven fabric made by ceramic fibers. 5. The joint for a flexible tube according to claim 1, wherein the ceramic fibers constituting the packing include silica and alumina. 6. The joint for a flexible tube according to claim 1, wherein the non-woven fabric forming the packing is a mixture of ceramic fibers and pulp. 7. The flexible tube joint according to claim 1, wherein the non-woven fabric forming the packing is made of a non-woven fabric. 8. The flexible tube joint according to claim 1, wherein the packing is subjected to a water repellent treatment. 9. The joint for a flexible tube according to claim 8, wherein the packing is subjected to a water-repellent treatment not only on its surface but also on its inside. 10. A method for producing a packing used for a flexible tube joint according to any one of claims 7 to 9, wherein a suspension containing ceramic fibers is formed during nonwoven fabric making. A liquid repellent is added to the liquid.