JPH07119877A - Coupling for flexible tube - Google Patents

Abstract

PURPOSE:To reduce the fastening force and the fastening time in the connecting work, and to confirm that a flexible tube is pressed in normally, by pressure contacting about one crest amount at the front end of the flexible tube. CONSTITUTION:A coupling for flexible tube consists of a coupling main body 1, a nut 2, a retainer 3, a gasket 4, an O ring 5, and a watertight packing 6. On the other hand, to the front end of the flexible tube to be connected, A cutting part 7a, the first crest 7b to be squashed, the first valley 7c, the second crest 7d, the second valley 7e... are formed from the front end, and its outer surface is covered by a protective membrane 8 made of a synthetic resin. The retainer is inserted while remaining one crest at the front end of the flexible tube, and as a result, the one crest at the front end is pressure contacted and squashed to the bottom wall, through the gasket 4 when explained in detail. Consequently, the friction and the pressing torque between members in a fastening work are reduced, and its working time is also reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flexible pipe joint for connecting a bellows-shaped flexible pipe.

[0002]

2. Description of the Related Art Conventionally, a joint for connecting a flexible pipe formed in a bellows shape (hereinafter sometimes referred to as a flexible pipe) has been disclosed in, for example, Japanese Patent Publication No. 3-3837 shown in FIG. There is something. In connecting the joint and the flexible pipe, first, the cap nut 83 is inserted into the flexible pipe 10, and the retainer 80 having the inner surface for engaging the corrugation and having the slit in the axial direction is opened to open the distal end of the flexible pipe. Attach to the section. After that, insert this into the large diameter hole 85 of the joint body 88, screw the female thread 82 of the cap nut and the male thread 84 of the joint body, and make a few peaks protruding from the end surface of the retainer 80 to the end surface of the retainer 80. And the gasket 89 are crimped, that is, crushed and connected, which is called, for example, a tightening type.

In addition, there is another disclosed in Japanese Utility Model Laid-Open No. 3-73785. In this joint, as shown in FIG. 10, the joint body 90 and the tightening member 91 are preliminarily assembled, and a snap ring capable of expanding the diameter is provided.
93 is arranged between the tip surface of the tightening member 91 and the packing 92, the snap ring 93 is expanded while passing through and the flexible pipe 10 is inserted, and then the tightening member 91 is fully added to the joint body 90. Retaining ring 93 while tightening to prevent expansion of retaining ring 93
The packing 92 is pushed in to crush and connect several peaks of the flexible pipe in front of the retaining ring 93 to the inner wall 94 of the joint body, which is called, for example, a retightening type.

Recently, there has been proposed a so-called one-touch type joint (for example, Japanese Patent Laid-Open No. 5-164280) in which the connection is completed by pushing the flexible pipe into the joint body, but in the case of this joint, the tightening work and the additional tightening are performed. Since it has no function, it cannot be completely sealed by crushing the tip of the flexible pipe. Especially for gas, it is not preferable if there is concern about the sealing performance.
Actually, as in the above-mentioned two examples, the tightening type and the retightening type which crush at least a few peaks of the flexible tube are put to practical use.

[0005]

The former one of the above-mentioned conventional flexible pipe joints has a problem that it takes time and labor for connection work because the joint parts are once disassembled and then assembled. Originally, this is a tightening work that involves friction, and since several tips (2 to 5 threads) of the flexible pipe are crushed, a considerable force is required for this tightening work, and the cap nut must be rotated many times. So it takes a long time.

In the latter case, the connection is completed only by preliminarily preliminarily preliminarily assembling the flexible tube and then tightening it again, so that the working time is relatively short. However, since several peaks of the flexible tube are to be crushed to the inner wall here, the additional tightening amount of the tightening member is set to an amount corresponding to the pitch of approximately three peaks of the flexible tube. The problem here is that there is no guarantee that the three peaks will pass through the retaining ring when the flexible tube is pushed in, and there is no means for confirming this. That is, even if it does not pass through one or two mountains, the amount of tightening is the same. In such a case, even if additional tightening is performed, the tightening amount for two peaks or one peak is insufficient, and there is a problem that the peaks cannot be crushed completely and leakage occurs from here. In order to solve this problem, it is conceivable to give a margin to the additional tightening amount, for example. However, in this case, since the number of screwing rotations of the tightening member is further increased, there is a problem that a large amount of force and time are required for the connection work as in the previous example.

The present invention solves the above problems,
An object of the present invention is to provide a flexible pipe joint having a function that can reduce tightening force and time in connection work and can easily confirm that a flexible pipe has been normally pressed.

[0008]

According to the present invention, at least a joint body, a nut and a retainer are provided, and the tip end of a bellows-like flexible pipe to be connected is engaged with the retainer and crimped to the inner wall of the joint body. The flexible pipe joint is a tightening type flexible pipe joint in which approximately one ridge at the tip of the flexible pipe is crimped.

As an example thereof, a retainer having an inner surface for engaging the outer surface of a bellows-like flexible tube and having slits in the axial direction, a front end surface for abutting the rear end surface of the retainer, and an inner diameter for inserting the flexible tube are provided. A large-diameter hole that has a nut having a thread formed on the front part and a female screw that is screwed onto the male thread of the nut at the front part A joint for a flexible pipe of a tightening type, comprising a portion, a large-diameter hole portion, and a joint body having an inner wall to which one tip of the flexible pipe is crimped.

Further, according to the present invention, there is provided a retainer having a plurality of slits in the axial direction, the front end of which is engaged with the valley portion of a flexible tube having a bellows shape, and the front portion to which the retainer is locked and the flexible tube. It has an inner diameter that can be inserted and a nut with a thread formed on the front part, and a female thread on the front part that is screwed onto the male thread of the nut, and the rear part has a reduced diameter hole and a back wall into which the front end part of the retainer fits. The joint body and the nut are configured such that when one tip of the flexible pipe gets over the front end portion of the retainer and abuts on the back wall, the front end portion engages with the next valley portion. It is a retightening type flexible pipe joint that is pre-screwed with such an amount of retightening so that one tip of the flexible tubing is crimped to the inner wall when retightening.

Further, the present invention provides a flexible pipe joint, comprising at least a joint body, a nut and a retainer, wherein the tip end of a bellows-like flexible pipe to be connected is engaged with the retainer and crimped to the inner wall of the joint body. , The retainer is expandable / contractible, expanded in diameter and accommodated in the joint body, and in a free state, the tip 1 of the flexible pipe is
A joint for a flexible pipe, which is adapted to be crimped to approximately one ridge at the tip of the flexible pipe when the joint body and the nut are retightened by engaging with an outer surface having a ridge.

As an example thereof, a retainer which has an inner surface engaging with the outer surface of a bellows-like flexible tube and a plurality of slits in the axial direction and which is expandable / contractible and engages with the valley portion of the flexible tube when the diameter is reduced, A wall that abuts the rear end of the retainer, an inner diameter that allows the flexible tube to be inserted, and a nut that has a female thread formed on the front part are interposed between the retainer to expand the retainer to the inner side of the flexible tube. Has a locking member placed so as to release the diameter expansion by the movement of the nut, and a male screw threaded to the female thread of the nut at the front part, and a housing part and a back wall of the locking member at the rear part. The joint body is formed, and the joint body and the nut are interposed via a retainer, and when the tip of the flexible pipe comes into contact with the inner wall, the retainer is reduced in diameter and leaves one ridge at the tip to engage with the outer surface thereof. Leave a tightening amount Pre is screwed, the one peak fraction tip of the flexible tube when tightening may tighten type flexible pipe joint which is adapted to crimp the inner wall.

[0013]

First, in the case of the tightening type flexible pipe joint, since the tip of the flexible tube is crushed by only one ridge, the tightening force, especially the force of crushing the ridge after abutting against the back wall is reduced. Further, the rotation of the nut is reduced, and the time required for connection work is shortened.

Next, in the case of a retightening type flexible pipe joint, the joint body and the nut are pre-tightened in such a manner that the distance between the front end of the retainer and the back wall allows only one tip of the flexible pipe to pass. It is assembled with leaving. That is, 1
When the mountain passes through the front end of the retainer, the tip collides with the inner wall and cannot move any further. In this state, if the flexible pipe is once pulled out, the flexible pipe cannot be pulled out because the front end portion of the retainer is locked in the first valley portion. This makes it possible to confirm that the flexible tube has been properly inserted.
Conversely, if you try to pull out the flexible tube and it actually comes out, the tip still has not passed through the retainer by one ridge, and you can see here the need to push it in further. Further, as with the tightening type, the force required for tightening and the time required for connection are shortened. still,
The same operation as described above can be achieved in a case where the retainer in the expanded diameter state is reduced in diameter due to the insertion of the flexible pipe to crush one peak at the tip.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view of a flexible pipe joint showing a first embodiment, showing a state after connecting a flexible pipe. This flexible pipe joint includes a joint body 1, a nut 2, a retainer 3, a gasket 4, an O-ring 5, and a watertight packing 6.
Consists of. On the other hand, the tip portion of the flexible pipe 7 to be connected has a cutting portion 7a from the tip portion, and the first mountain portion 7 to be crushed.
b, the first valley portion 7c, the second mountain portion 7d, the second valley portion 7e, ...
Is formed and the outer surface is made of a synthetic resin protective layer 8
Is covered by.

In the joint body 1, a female screw portion 11, a large-diameter hole portion 12, and a rear wall 1 from the front inlet side (left side in the drawing) toward the rear side.
3, the small diameter hole portion 14 is formed, and the large diameter hole portion 12 is a tapered surface whose diameter decreases toward the inner side, and the retainer 3 is fitted therein. Further, although the gasket 4 is attached to the back wall 13, the gasket is not always necessary and the back wall may be directly formed. From the front (right side in the drawing) of the nut 2, when the retainer 3 is fitted into the large-diameter hole 12, the front end face 21 comes into contact with the rear end face of the retainer, and the male screw 22 is screwed to the female screw of the main body at the front part. An inner diameter that allows the flexible tube to be inserted and a watertight packing 6 that hermetically seals the outer surface of the flexible tube are formed.

The retainer 3 has a corrugated inner surface that engages with the outer surface of the bellows-shaped flexible tube and is provided with slits in the axial direction. At the time of assembling, the slit is opened to leave one tip of the flexible tube, and the inner surface is attached so as to engage with the first trough portion to the second trough portion. The connection procedure of the above-mentioned joint is almost the same as that of the conventional tightening type joint, so detailed description will be omitted, but the feature is that the retainer is inserted leaving one tip of the flexible pipe, and as a result, this tip 1 The mountain is about to be pressed and crushed against the inner wall 13, more specifically, via the gasket 4. Therefore, the friction between members in the tightening work and the pressing torque are reduced, and the working time is shortened.

2 to 5 are sectional views of a retightening type flexible pipe joint showing a second embodiment. FIG. 2 is a sectional view showing a state before inserting the flexible tube, FIG. 3 is a sectional view showing a state where the flexible tube is inserted, and FIG. 4 is a sectional view showing a state of connection completion after retightening. This flexible pipe joint includes a joint body 10, a nut 20, a retainer 30, a gasket 40, an O-ring 50, and a watertight packing 60. On the other hand, the flexible pipe 7 to be connected is, as shown in FIG. 3, similar to the above, the cutting portion 7a from the tip portion, the first crest portion 7b to be crushed, the first trough portion 7c, the second trough portion 7d, and the second trough portion. 7e, ......... are formed,
The outer surface is covered with a protective layer 8 made of synthetic resin.

The joint body 10 has a female screw 15 that is screwed into the nut from the inlet side (left side in the drawing) toward the inner side, an annular recess 16 slightly larger than the inner diameter of the female screw, and a taper that reduces in diameter toward the end. Reduced-diameter hole portion 17 having an inner surface and through hole 18
A back wall 19 is formed as a stepped surface between and. Although the gasket 40 is attached to the back wall 19, the gasket is not always necessary and the back wall may be directly formed. Further, although the reduced diameter hole 17 is formed by a tapered surface, it may be a parallel inner surface. The nut 20 has a male screw 23 that is screwed into the female screw 15 of the main body 10 on the outer peripheral surface from the front part (right side in the drawing), and a retainer 30 described later on the inner surface of the front end part that is rotatable and axially movable. O-ring 50 that engages with the long recessed engagement groove 24 and the outer periphery of the rear portion of the male screw 23 that performs external sealing after the additional tightening is completed.
A watertight packing 60 is formed to seal the inner diameter of the flexible tube and the outer surface of the flexible tube. The engagement groove 24 may be provided on the inner surface of the end portion as shown in the figure, or an annular dovetail groove may be provided on the front end portion of the nut to rotatably engage the retainer 30.

The retainer 30 is a retainer for the flexible pipe, and as shown in FIG. 5, the retaining portion 3 has four dividing grooves 35a to 35d in the circumferential direction for retaining the outer surface wave crests of the flexible pipe.
1 and an annular guide body 32 having an engagement protrusion that is fixed to the rear end of the engagement portion to hold the engagement portion 31 in an annular shape and engages with the engagement groove 24 of the nut 20. The retainer 30 including the locking portion 31 and the guide body 32
Are locked to the nut 20 so as to be rotatable and axially movable. In this case, since the guide body 32 is made of resin, the guide body 32 is inserted into the engagement groove 24 while being slightly contracted in the inner diameter direction so that the guide body 32 is fitted into the snap groove. The locking portion 31 of the retainer 30 and the guide body 32 may be integrally formed of resin as long as the strength is sufficient for crimping the distal end portion of the flexible pipe. 32 may be formed of a resin and fixed integrally with an adhesive, or both may be formed of an integral metal having elasticity. Further, the front end surface 33 of the locking portion 31 has a single projecting shape that locks to the first valley portion 7c of the flexible tube 7 in the figure, but it has a plurality of locking peaks other than one peak of the flexible tube 7 at the tip. It may be wave-shaped.

Next, the procedure for connecting the flexible pipe joint of this embodiment will be described. FIG. 2 shows a state before the flexible pipe 7 is inserted. First, in the joint body 10 and the nut 20, the distance between the front end portion 33 of the retainer 30 fixed to the nut and the inner wall (including the gasket 40 in this case) is set. , With a retightening amount such that when one tip of the flexible pipe gets over and comes into contact with the back wall, it is locked in the next valley (first valley), that is,
When one mountain passes through the front end portion of the retainer, the tip end is pre-screwed to a position where it collides with the inner wall and cannot move further. On the other hand, at this time, the locking portion 31 of the retainer 30 is also in a state in which the diameter can be expanded in the annular recess 16 of the main body 10. In other words, the front end portion 33 of the locking portion 31 has the reduced diameter hole portion 1
The position is such that it does not fit in 7. A collar 34 is attached between the ends of the main body 10 and the nut 20 to maintain this screwed state.

Next, when the flexible pipe 7 to be connected is inserted from the rear end of the nut 20, the first first mountain portion 7b of the flexible pipe 7 pushes the front end 33 of the retainer 30 and spreads it, as shown in FIG. I slipped through, hit the back wall, and couldn't move any further. In this state, the front end portion 33 is fitted and locked in the first valley portion. Therefore, even if the flexible pipe 7 is pulled out here, the front end portion does not come out of the joint body by engaging with the valley portion. If further pulling out is attempted, the front end portion fits into the inner diameter surface on the front side, and pulling out can be prevented more strongly. On the contrary, if the flexible pipe comes out here, it means that no one ridge has passed through the front end portion 33 of the retainer, and it is confirmed that further pushing is necessary.

Next, the collar 34 is removed, and the nut 20 is rotated and tightened to the joint body 10 again. As shown in FIG. 4, the front end surface 25 of the nut 20 abuts against the rear end surface of the guide body 32 of the retainer 30 and is locked. The part 31 is pushed into the reduced diameter hole 17.
Therefore, the front end portion 33 of the locking portion 31 is completely fitted into the first valley portion and pressed toward the back wall side while reducing the diameter of the first peak portion of the flexible tube 7. At this time, the nut 20 is rotated, but the retainer 30 is rotatably engaged with the nut 20. Therefore, the retainer 30 is locked by the friction resistance reduced by the diameter reducing hole 17 and does not rotate. In this way, one peak at the tip is sandwiched between the retainer and the back wall via the gasket, and this sandwiching completely seals the flexible pipe and the joint body. Further, after the tightening is completed, the O-ring 50 and the T-type packing 60 perform external sealing, so that corrosive water does not enter the connection portion. As described above, the connection of the flexible pipe 7 is completed.

6 to 8 are sectional views of a retightening type flexible pipe joint showing a third embodiment. FIG. 6 is a sectional view showing a state before inserting the flexible tube, FIG. 7 is a sectional view showing a state where the flexible tube is inserted, and FIG. 8 is a sectional view showing a state of connection completion after retightening. This flexible pipe joint includes a joint body 51, a nut 52, a retainer 53, a locking member 54, a reduced diameter ring 55, an O ring 56, and a watertight packing 46. In this embodiment, the locking member 54 also serves as a gasket. On the other hand, the flexible tube 7 to be connected is the same as that of the above-mentioned embodiment, and therefore the description thereof is omitted here.

The joint body 51 includes a male screw 41 screwed into a nut from the inlet side (left side in the drawing) toward the inner side, and the through hole 5.
An inner wall 57 that is a stepped surface between the inner wall 57 and the inner wall 9 is formed.
From the front part (right side in the drawing) of the nut 52,
A female thread 42 that is screwed into the male thread 41, a rear wall 43 that holds a retainer 53, which will be described later, between the male thread 41 and a front end surface 44 of the joint body on the inner surface of the rear end, and an inner diameter that allows the flexible tube to be inserted. Has been formed.

The retainer 53 is a retainer for the flexible tube, which is expandable / contractible and is adapted to engage with the first trough portion and thereafter of the flexible tube when the diameter thereof is reduced. Explaining this with reference to FIG. 5, for example, it has a shape having a corrugated inner surface that locks to the outer surface of the flexible tube and four dividing grooves 35a to 35d provided in the circumferential direction, and between the respective dividing grooves. Locking member 54
The protruding portion 45 is intervened to expand the diameter, and the diameter reducing ring 55 having a contracting force in the inner diameter direction is fitted on the outer periphery of the retainer so that the diameter can be reduced.

The locking member 54 comprises a protruding portion 45 and a gasket portion, and the protruding portion is intervened in advance between the retainers as described above. Then, when the flexible pipe is inserted, the cutting portion 7a pushes the gasket portion inward, and when the first crest portion 7b passes through the retainer 53, the engagement of the protruding portion 45 with the retainer is released, and then the retainer 53 contracts. The diameter of the flexible tube is reduced by the force of the radial ring 55, and the flexible tube is engaged from the first valley portion to the second valley portion.

Next, the procedure for connecting the flexible pipe joint of this embodiment will be briefly described. FIG. 6 shows a state before the flexible pipe 7 is inserted. As described above, when the retainer 53 is reduced in diameter, the retainer 53 is increased so as to be locked from the first trough to the second trough except one tip of the flexible pipe. It is screwed in advance so as to be sandwiched between the joint main body 51 and the nut 52 while leaving the tightening amount. Then, the collar 58 is attached to maintain this screwed state.

Next, when the flexible pipe 7 to be connected is inserted from the rear end of the nut 52, the tip cutting portion 7a of the flexible pipe 7 pushes the locking member 54 inward as shown in FIG.
At the same time, the engagement of the protruding portion 45 is released, and the retainer 53 is reduced in diameter to be engaged, leaving one ridge at the tip of the flexible tube. Therefore, even if the flexible pipe 7 is pulled out here, it does not come out from the joint body. On the contrary, if the flexible pipe comes out, it means that the flexible pipe has not passed through the retainer portion, and it can be confirmed that it is necessary to further push it in.

Next, when the collar 58 is removed and the nut 52 is rotated and further tightened to the joint body 51, the retainer 53 advances to the back side as shown in FIG. 8 and one mountain at the tip is between the retainer and the back wall. The flexible pipe and the joint body are completely sealed by this sandwiching. As described above, the connection of the flexible pipe 7 is completed.

The above is an embodiment in the case of using a retainer whose diameter can be freely expanded. However, the present invention is not limited to this, and the retainer is engaged with the outer surface of the flexible pipe in which one tip end is left in a free state,
When the joint body and nut are retightened, the tip of the flexible pipe 1
Any structure may be used as long as it is configured to press the mountain.

[0032]

As described above, in the flexible pipe joint of the present invention, only one tip of the flexible pipe is crushed, so that the tightening force and time in the connecting work can be shortened. Even if the flexible tube can be connected simply by pushing it in and tightening the nut, there is a function to easily check whether the flexible tube is properly pushed in when it is pushed in, so there is no connection mistake. It can be prevented.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view after connecting a flexible pipe showing a first embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view showing a second embodiment of the present invention and showing a temporarily assembled state.

FIG. 3 is a vertical sectional view showing a state in which a flexible tube is also inserted.

FIG. 4 is a vertical cross-sectional view showing a state after the flexible pipe is similarly connected.

FIG. 5 is a view showing a right side view of the retainer as well.

FIG. 6 is a vertical cross-sectional view showing a third embodiment of the present invention and showing a temporarily assembled state.

FIG. 7 is a vertical sectional view showing a state in which a flexible tube is likewise inserted.

FIG. 8 is a vertical cross-sectional view showing a state after the flexible pipe is similarly connected.

FIG. 9 is a vertical cross-sectional view showing an example of a conventional flexible pipe joint.

FIG. 10 is a longitudinal sectional view showing another example of a conventional flexible pipe joint.

[Explanation of symbols]

1, 10, 51 ... Joint body 2, 20, 52 ... Nut 3, 30, 53 ... Retainer 4, 40, 54 ... Gasket 5, 50, 56 ... O-ring 6, 60 ... Watertight packing 7 ... Flexible pipe 8 ... Resin Coating layer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshiyuki Ueno 71-4 Yukojihama, Joetsu City, Niigata Prefecture (72) Inventor Shinichi Kamata 3-1-21-108 Kamigusa, Suginami-ku, Tokyo (72) Inventor Takashi Anamizu 21 Noto-cho, Shinjuku-ku, Tokyo 404 Hydens, Noto-cho, Ichigaya 404 (72) Inventor, Jetsuo Saito 1-11-11 Unoki, Ota-ku, Tokyo (72) Fumitaka Sato 3-27 Nishi-ichinoe, Edogawa-ku, Tokyo 15

Claims (5)

[Claims] 1. A flexible pipe joint comprising at least a joint body, a nut, and a retainer, wherein a tip end of a bellows-like flexible pipe to be connected is engaged with the retainer and crimped to a back wall of the joint body. A flexible pipe joint characterized in that approximately one ridge at the tip of the pipe is crimped. 2. A retainer having an inner surface that engages with the outer surface of a bellows-shaped flexible tube and having a slit in the axial direction,
A nut having a front end face abutting the rear end face of the retainer and an inner diameter capable of inserting the flexible pipe and a screw formed on the front portion;
The front portion has a female thread to be engaged with the male thread of the nut, and the rear portion has a large-diameter hole portion into which a retainer engaged with leaving one tip of the flexible tube is inserted and one tip of the flexible tube. A joint for a flexible pipe, which comprises a joint body having an inner wall to be crimped. 3. A plurality of slits are provided in the axial direction,
A retainer whose front end engages with a trough of a bellows-shaped flexible pipe, a front part to which the retainer is locked, an inner diameter through which the flexible pipe can be inserted, and a nut formed with a screw on the front,
The front part has a female thread to be screwed into the male thread of the nut, and the rear part is composed of a reduced diameter hole into which the front end of the retainer fits and a joint body having a back wall. , When one tip of the flexible pipe gets over the front end of the retainer and comes into contact with the back wall, the front end is pre-screwed with an additional tightening amount so that the front end engages with the next trough. A joint for a flexible pipe, characterized in that when it is tightened, one tip of the flexible pipe is crimped to the inner wall. 4. A flexible pipe joint comprising at least a joint body, a nut, and a retainer, wherein a tip end of a bellows-shaped flexible pipe to be connected is engaged with the retainer and crimped to a back wall of the joint body. Is expandable / contractible, expanded in diameter and accommodated in the joint body, and in the free state, engages with the outer surface of the flexible pipe with one tip remaining, and when the joint body and the nut are retightened, the tip of the flexible pipe is The joint for flexible pipes is characterized in that approximately one mountain is crimped. 5. A retainer which has an inner surface engaging with the outer surface of a bellows-like flexible pipe and a plurality of slits in the axial direction, and which is expandable / contractible and engages with the outer surface of the flexible pipe when the retainer has a reduced diameter. A wall that abuts the rear end and an inner diameter that allows the flexible tube to be inserted and a nut that has a female thread formed on the front part are interposed between the retainer and the retainer to expand the diameter to move the flexible tube to the inner side. A joint having a locking member placed so as to release the expanded diameter and a male screw threaded to the female thread of the nut in the front part, and a housing part of the locking member and a back wall formed in the rear part. The joint main body and the nut are interposed via a retainer, and the diameter of the retainer is reduced when the distal end of the flexible pipe comes into contact with the inner wall, and
A joint for a flexible pipe, which is pre-screwed with a retightening amount such that a mountain portion is left and engages with an outer surface of the ridge, and when the retightening is performed, one tip of the flexible pipe is crimped to a back wall.