JP3403149B2 - Flexible pipe joint - Google Patents

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, and more particularly to a flexible pipe joint to which a flexible metal bellows pipe is connected.

[0002]

2. Description of the Related Art Flexible pipe joints include those shown in FIGS. This flexible pipe joint consists of a joint body (5) connected to the gas inlet (G) of the gas cock and this joint body (5).
Tightening tube (51) screwed in from the rear part (left end in the drawing)
And an annular retainer (52) that is rotatably connected to the front end of the tightening cylinder (51) and is pushed into the retainer housing cylinder part (50) of the joint body (5) by tightening the tightening cylinder (51). 6 is a sectional view showing a temporary tightening state of the tightening cylinder (51) before final tightening, and FIG. 7 shows a state in which the tightening of the tightening cylinder (51) is completed (a bellows pipe (8 FIG. 4 is a cross-sectional view showing (when connection is completed)).

The tightening cylinder (51) is composed of a small-diameter body portion screwed into the joint body (5) and a spanner engaging portion (51a) continuous to the rear of the small-diameter cylinder portion. There is. Retainer (5
2) is divided into a plurality of divided members by a plurality of slits formed in the circumferential direction from the front end side, the front end portion is formed with a biting portion (53) to be fitted onto the valley portion of the bellows tube (8). In addition, the rear end is rotatably attached to the front end of the tightening cylinder (51).

In this case, the fitting body (5) is attached to the tightening cylinder (51).
And the bellows pipe (55) between the biting part (53) of the retainer (52) and the pipe receiving surface (55) located in front of the retainer housing cylinder part (50) of the joint body (5). 8) A space larger than the size of one mountain is formed, and the biting part
Tightening tube until it reaches the temporary fixing position where (53) corresponds to the retainer expansion allowance recess (54) formed in the joint body (5).
Tighten (51).

A spacer for positioning is provided between the front end surface of the spanner engaging portion (51a) of the tightening cylinder (51) and the rear end portion of the joint body (5) for positioning at the temporary fixing position. The ring (56) is interposed. As a result, when the small-diameter cylinder portion of the tightening cylinder (51) is screwed into the joint body (5) and tightened, the spacer ring (56) causes the front end face of the spanner engaging portion (51a) and the joint body. (5) The tightening cylinder (51) cannot be tightened any more when it comes into contact with the rear end portion at the same time. The state in which this tightening is blocked corresponds to the state in which it is positioned at the temporary fixing position.

The bellows pipe (8) is inserted from the rear of the tightening cylinder (51) into the flexible pipe joint in which the tightening cylinder (51) is set at the temporary fixing position, and the front end of the retainer (52) is expanded. While elastically deforming in the opening direction, as shown in FIG. 6, the insertion end of the bellows tube (8) is projected forward of the retainer (52). At this time, since the front end portion of the retainer (52) is fitted into the retainer expansion allowing recess (54), the expansion of the retainer (52) is not blocked, and the bellows pipe (8 ) Can be inserted.

In this state, the spacer ring (56) is removed and the tightening cylinder (51) is further tightened to the final tightening position. Then, as shown in FIG. 7, the retainer (52) is
The bite of the retainer (52) is pushed by (51) and moved to the front (right side in the drawing) of the joint body (5), and is pushed into the retainer housing tubular part (50), and the diameter of the retainer (52) is reduced. The part (53) bites into the valley part of the bellows tube (8). In this state, by further tightening the tightening cylinder (51), the insertion end portion of the bellows tube (8) is compressed between the front surface portion of the biting portion (53) and the pipe receiving surface (55). That makes the bellows tube (8)
Connection is completed.

[0008]

In this conventional device,
If the tightening cylinder (51) equipped with the retainer (52) is screwed onto the joint body (5) and temporarily fixed, the bellows tube (8) can be inserted and tightened without disassembling during construction. The bellows tube (8) can be connected only by tightening the tube (51) to the final tightening position.

However, in the conventional flexible pipe joint, a positioning spacer ring (56) is interposed in order to position the tightening cylinder (51) in the joint main body (5) at the temporary fixing position. Therefore, the number of parts is large and the structure is complicated. Moreover, the spacer ring (5
6) has a problem that the work of connecting the bellows tube is troublesome because it must be removed when the tightening cylinder (51) is tightened to the final tightening position. Especially the fitting body (5)
However, if it is attached to the gas inlet (G) of the gas cock that is difficult to see from the outside and is arranged in a narrow place, it is difficult and difficult to remove the spacer ring (56), which is a problem. .

The present invention relates to a "cylindrical joint main body, a tightening cylinder which is inserted into the joint main body from the rear and is positioned at a temporary fixing position in the joint main body, and is connected to a front end of the tightening cylinder. The retaining tube is configured to hold the bellows tube in the temporarily fixed state at the temporarily fixed position, and the retainer is configured to be expandable and contractable in the radial direction. When the cylinder is tightened from the temporarily fixed position to the final tightened position, the front end is expanded by being pushed into the retainer housing cylinder provided at the front end in the joint body while being fitted onto the bellows pipe. In a flexible pipe joint that is maintained in an open state, it is possible to easily temporarily fix the tightening tube in the joint body without a spacer ring for positioning, and to facilitate the work of connecting the bellows pipe. And <Item 1>

[0011]

[Means for Solving the Problems] The solution means of the invention taken to solve the above-mentioned problems is that "a male screw portion is formed in a certain range of the outer circumference of the body of the tightening cylinder, The first and second female screw portions to which the male screw portion is screwed are provided in the front and rear through the non-threaded portion, and the first female screw portion is provided near the rear open end of the joint body. 2 The female screw portion is formed so as to be located in the vicinity of the retainer housing cylinder portion, the inner diameter of the non-screw portion is set to be larger than the mountain diameter of the male screw portion, and its axial length is The retainer is set to be longer than that of the male screw portion, the retainer can be expanded in the second female screw portion, and the retainer thread portion at the tail end of the second female screw is provided at the front end of the male screw portion. When the screw threads come into contact with each other, the tightening cylinder is fixed in the joint main body at the temporary fixing position. The front end of the retainer while being positioned is that "it is set to correspond to the second female thread portion.

The above-mentioned solving means operates as follows. When the tightening cylinder is inserted into the joint main body from the retainer side connected to the front end of the tightening cylinder, the tightening cylinder is attached to the rearmost thread of the first female screw portion formed on the open end side in the joint main body. The screw thread portion at the front end of the male screw portion formed on the body portion of the blade abuts. When the contact is made, the tightening cylinder is tightened and both are screwed together, whereby the tightening cylinder moves forward in the joint body.

When the rear end of the male screw portion is located in front of the first female screw portion, the male screw portion is not screwed into the non-threaded portion formed next to the first female screw portion. It becomes a mode that fits in the state. Since the axial length of the non-threaded portion is set to be longer than the length of the male threaded portion, the male threaded portion is slidably movable in the front-rear direction within the non-threaded portion and is slid forward. And the threaded portion at the front end of the male threaded portion abuts on the rearmost threaded portion of the second female threaded portion formed in front of the non-threaded portion, and further sliding is inserted. I can't. This position is a temporary fixing position of the tightening cylinder in the joint body, and the first female screw portion is located at the rear side, so that the body of the tightening cylinder is positioned in the joint body in a retaining state. .

When a bellows tube as a flexible tube is inserted into the temporarily assembled flexible tube joint from the rear of the tightening tube, the tipmost peak of the bellows tube expands the diameter of the retainer. , Project to the front of the retainer. Since the retainer is positioned so as to be able to expand within the area where the second female threaded portion is formed, the retainer is pushed by the leading edge of the bellows tube to expand its diameter and pass through the bellows tube. Can be made. The bellows tube is temporarily fixed in a state in which the front end of the retainer is externally fitted to the valley part of the bellows tube that continues to the crest part. When the tightening tube is tightened from this state, the male thread portion of the tightening tube is screwed into the second female thread portion, whereby the positioning state of the tightening tube at the temporary fixing position is released, and the tightening tube is tightened. The attached cylinder can be moved further forward in the joint body. After that, like the conventional one, the retainer is pushed into the retainer accommodating cylinder part in the joint body while pressing the crest part of the bellows pipe, and its front end is held in the expansion preventing state, and the tightening cylinder is the last. When tightened to the tightening position, the connection of the bellows tube is completed.

<2> In the invention described in detail in the above item 1, “The retainer is formed so that a biting portion which is externally fitted to a trough portion of the bellows tube is protruded inward at the front end portion. At the same time, a cylindrical body having a substantially C-shaped cross section is formed on the outer peripheral edge of the rear end portion, and a tapered outer peripheral surface is formed. The small diameter cylindrical portion is provided in front of the body portion of the tightening cylinder. Is formed to be extended, and the rear end portion of the retainer is movable in the front-rear direction and externally fitted and connected to the small-diameter tubular portion in a retaining state, and the retainer is attached to the rear end of the small-diameter tubular portion. In the state in which the bellows pipe is inside the joint body, a pressing portion for pressing the tapered outer peripheral surface is formed on the front end surface of the body portion of the tightening cylinder that is opposed to the tapered outer peripheral surface in the state of being moved. When inserted into, the biting part is pushed by the mountain part at the tip of the bellows tube, and the cross section is approximately C-shaped. Formed retainer will be expanded in the radial direction together is moved to the front end of the small diameter cylinder portion of the clamping cylinder, the mountain portion of the bellows tube is made can be inserted between the bite. On the contrary, if the bellows tube in which the mountain portion is located forward of the biting portion is to be pulled out backward, the biting portion is pushed backward by the rear surface of the mountain portion and the retainer moves backward. While being moved, its rear end contacts the rear end of the small diameter cylinder. At the front end surface of the body portion of the tightening cylinder corresponding to the rear end of the small-diameter cylindrical portion, a pressing portion for pressing the tapered outer peripheral surface formed at the rear end of the retainer is formed. The more the pressure is applied, the more the tapered outer peripheral surface is pressed by the pressing portion in the diameter reducing direction.

<3> In the invention described in detail in the above item 2, “the pressing portion is a tapered inner peripheral surface formed so as to face the tapered outer peripheral surface”, a bellows tube is used. When attempting to pull it out, the tapered surface formed on the retainer is pressed in such a manner that it is in contact with the tapered surface formed on the tightening cylinder, and the retainer is reliably pressed in the diameter reducing direction.

[0017]

EFFECTS OF THE INVENTION By simply screwing the tightening tube into the joint body, the tightening tube is disengaged from the first female screw portion of the joint body and is screwed at the front end of the male screw portion. At the time when the thread portion comes into contact with the rearmost thread portion of the second female threaded portion, the tightening cylinder is positioned in the retaining position before the bellows tube is inserted. It is not necessary to separately prepare another member for positioning such as a ring. Therefore, the number of parts can be reduced and the cost can be reduced accordingly. Even if the fitting body is installed in a place where construction work is difficult to perform, such as in a narrow place, when tightening the tightening cylinder to the final tightening position, it is necessary to remove the positioning member like the conventional one. Since it is unnecessary, the work of connecting the bellows tube becomes easy.

According to the second aspect, in addition to the above effect, the retainer can be easily opened, and the bellows tube is inadvertently pulled rearward before the tightening cylinder is tightened to the final tightening position. In this case, the tapered outer peripheral surface formed at the rear end of the retainer is pressed by the pressing portion formed on the tightening cylinder, so that a force in the diameter reducing direction is applied to the retainer. Therefore, there is an effect that the posture of the retainer with the biting portion biting into the valley portion of the bellows tube is certainly maintained, and there is no inconvenience that the once inserted bellows tube is inadvertently pulled out. In the case of the constitution of the item 3, the effect of the item 2 becomes more reliable.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below.
It will be described with reference to the drawings. The flexible pipe joint according to the embodiment of the present invention has a tubular joint body as shown in FIG.
(1), a tightening tube (2) that is pushed forward of the joint body (1) (left side in the drawing), and a retainer (3) attached to the front end of the tightening tube (2) Fig. 1 shows the tightening cylinder.
FIG. 2 is an overall view showing a state in which (2) is located at a temporary fixing position in the joint body (1), and FIG. 2 is an enlarged cross-sectional view of the relevant part.
In addition, these joint body (1), tightening tube (2) and retainer (3)
Is made of a metal material such as brass or brass.

First, the joint body (1) will be described. On the outer periphery of the front end of the joint body (1), for example, a male screw (100) for screwing connection to the gas inlet of the gas cock is engraved. Then, on the inner circumference of the joint body (1), from the rear open end which will be the insertion port of the tightening cylinder (2) described later, to the male screw part (in the body of the tightening cylinder (2) ( No screw having the inner diameter that is equal to the root diameter of the first female screw portion (11) with which 29) is screwed, the first female screw portion (11) or is larger than the mountain diameter of the male screw portion (29). A part (13) and a second female screw part (12) having the same diameter as the first female screw part (11) are formed in order, and a small-diameter cylindrical shape is provided in front of the second female screw part (12). The retainer housing cylinder part (17) is continuously formed.

In other words, the first and second female screw portions (11) and (12) are formed before and after the area where the screwless portion (13) is formed, and the male screw portion (29) is screwed into each of them. It is configured to match. A gas passage (18) having a small diameter is formed further in front of the retainer housing cylinder (17). Between the rear end of the gas passage (18) and the front end of the retainer housing cylinder (17),
The annular pipe receiving surface (15) is formed so as to be positioned at a right angle to the inner peripheral surface of the retainer housing tubular portion (17). And
An annular groove (19) is formed outside the pipe receiving surface (15), and an O-ring (14) for ensuring airtightness with the bellows pipe (8) is loaded in the annular groove (19). Has been done.

Next, the tightening cylinder (2) will be described. The tightening cylinder (2) is composed of a spanner engaging part (22) having a hexagonal outer circumference and a body part (23) continuing to the front. From the front end of the body (23), a small-diameter cylinder (24) is further formed,
The male screw portion (29) described above is engraved in a predetermined outer peripheral area of the body portion (23) in the vicinity of the front end portion. Further, on the outer peripheral surface of the small-diameter cylindrical portion (24), an engaging recess (20) for engaging a rear end portion of a retainer described later is formed in an annular shape, and the annular recess (20) is formed. The side wall on the rear side and the outer peripheral edge of the front end portion of the body portion (23) are continuous by a tapered inner peripheral surface (21) whose diameter is reduced rearward.

Incidentally, the male screw portion (2
9) is the first female screw part (1) on the rear open end side of the joint body (1).
1) and the second female screw part (12) on the retainer housing cylinder part (17) side, and the length thereof is set shorter than the axial length of the non-screw part (13). There is. Further, a recess (25) extending over the entire circumference is formed on the inner circumference of the spanner engaging portion (22), and an annular packing (27) is loaded in the recess (25). . The annular packing (27) is for preventing rainwater and the like from entering the flexible pipe joint by coming into contact with the synthetic resin coating pipe (80) that covers the outer periphery of the bellows pipe (8). is there.

Finally, the retainer (3) will be described.
As shown in FIG. 3, the retainer (3) is a tubular body having a substantially C-shaped cross-section that is expandable and contractible in the radial direction and has one slit formed in the axial direction. Engagement part
The (30) can be forcibly engaged with the engagement recess (20) of the small diameter tubular portion (24) of the tightening tubular (2). As a result, the retainer (3) is rotatably connected to the front of the tightening cylinder (2).

The axial length of the engaging portion (30) is set to be smaller than the axial width of the engaging recess (20). Further, the outer peripheral edge of the rear end of the engaging portion (30) is a tapered outer peripheral surface (31), and the taper of the tapered outer peripheral surface (31) is the same as the above. Tightening tube (2)
Of the tapered inner peripheral surface (21).

At the front end of the retainer (3), a biting portion (33) is projected inward, and the inner diameter on the tip side is
Mountain part of the bellows tube (8) in a free state that does not expand or contract
It is set to be smaller than the diameter of (81) and slightly larger than the diameter of the valley portion (82). Further, the outer diameter of the front end side is slightly larger than the inner diameter of the retainer accommodating cylinder part (17) so that it can be accommodated in the retainer accommodating cylinder part (17) when the diameter is forcibly reduced. It is set.

A procedure for assembling this flexible pipe joint will be described. First, the retainer (3) is expanded in diameter as described above, and the rear end engaging portion (30) is attached to the small diameter tubular portion (24) of the tightening tube (2).
The retainer (3) and the tightening cylinder (2) are integrated by fitting the retainer (3) into the engaging recess (20). In this state, the engaging portion (30) of the retainer (3) is rotatably and slidably mounted in the engaging recess (20) of the small diameter tubular portion (24).

The connecting body of the tightening cylinder (2) and the retainer (3) is
From the side of the retainer (3), the male screw portion (29) is screwed into the first female screw portion (11) at the same time as it is inserted into the rear open portion of the joint body (1). As a result, the body portion (23) of the tightening cylinder (2) moves forward in the joint body (1), and the male screw portion (29).
Goes over the first female threaded portion (11) and fits into the next non-threaded portion (13).

Since the axial length of the non-screw part (13) is set longer than the length of the male screw part (29) as described above, the male screw part (29) has no screw part (13). It is possible to slide in the front-back direction in the bracket. Therefore, when the tightening cylinder (2) is moved forward, as shown in FIG. 2, the mountain portion (2) at the front end of the male screw portion (29) is
9a) abuts on the rearmost mountain portion (12a) of the second female screw portion (12). As a result, the tightening cylinder (2) is prevented from further insertion into the joint body (1). Further, since the first female screw portion (11) of the joint body (1) is located behind the male screw portion (29), the rearmost mountain portion of the male screw portion (29) is the first. By contacting the ridges of the female screw part (11), the tightening cylinder (2) is held even in the retaining state.

In this state, the tightening cylinder (2) is positioned in the joint main body (1) at the temporary fixing position. In this state, the retainer (3) is attached to the second female screw part (1) of the joint body (1).
2) The distance between the front end surface of the retainer (3) and the pipe receiving surface (15) facing the retainer (3), which is located in the formation region, is the bellows pipe (8).
It is assumed that the size is set to approximately match the size of one mountain. In addition, the inner diameter of the second female screw portion 12 is set to a size that allows the retainer 3 to expand.

Next, the bellows tube (8), which is a flexible tube, is inserted into the flexible tube joint from the rear of the tightening tube (2). Then, as shown by the solid line in FIG. 1, the frontmost ridge portion (81) of the bellows tube (8) comes into contact with the biting portion (33) of the retainer (3) from behind. From this abutting state, the bellows tube (8) is pushed further strongly, and the crest portion (81) is passed between the biting portions (33) while expanding the retainer (3). At this time, the retainer (3)
The second female thread (1) that is large enough to open the retainer (3)
Since it is located in 2), the front end side of the retainer (3) expands radially in the second female screw part (12), and the ridge part (81)
Can pass between the bites (33). After that, the retainer (3) returns to the above free state by its elastic return force, the biting part (33) bites into the valley part (82) following the mountain part (81), and the leading edge of the bellows tube (8). Only the mountain part (81) of
As shown by the chain double-dashed line in the figure, it projects forward from the retainer (3).

In this state, as shown by the arrow in FIG. 4, when a force in the pulling direction is applied to the bellows tube (8), the rear surface of the foremost ridge (81) is retained by the retainer (3). ) The biting part (33) is pushed rearward, and accordingly, the engaging part (30) moves rearward in the engaging recess (20). When the rear end of the engaging portion (30) comes into contact with the front end surface (corresponding to the rear side wall of the engaging recess (20)) of the body portion (23) of the tightening cylinder (2), at the same time, Engagement part
The tapered outer peripheral surface (31) of (30) is pressed against the tapered inner peripheral surface (21) on the side of the tightening cylinder (2).

As a result, the retainer (3) is attached to the tightening tube (2).
Since a force in the diameter reducing direction is applied by the tapered inner peripheral surface (21), even if the biting portion (33) is pushed in the expanding direction by the rear surface of the mountain portion (81). The expansion of the retainer (3) is prevented. In this way, the bellows tube (8) is reliably positioned in the joint main body (1) in the temporarily fixed state, and does not fall out accidentally.

From the temporarily fixed state of the bellows tube, the tightening tube (2)
Is further tightened to screw the male screw part (29) into the second female screw (12) of the joint body (1). Then, as shown in FIG. 5, in the retainer (3), the bite portion (33) is fitted onto the valley portion (82) following the peak portion (81) of the bellows pipe (8), and the peak portion (33) is 81)
The surface on the rear side of the retainer (3) is pushed forward by the biting portion (33), and the front end portion of the retainer (3) is pushed into the retainer housing tubular portion (17) and is held in the expansion preventing state. .

As a result, the bellows pipe (which is located between the front surface of the biting portion (33) and the open end of the annular groove (19) corresponding to the outer end of the pipe receiving surface (15) ( 8) Frontmost mountain part
(81) is a part of the mountain portion (81) which is pressed against the open end of the annular groove (19) by the front surface of the bite portion (33) and is crushed and which projects outward more than the outer end edge. Is pushed into the annular groove (19), and is pressed by the front surface of the split member (30) together with the O-ring (14) into a pressed state. This is the state where the connection of the bellows tube (8) is completed.

Even when the connection of the bellows tube (8) is completed, by loosening the tightening of the tightening tube (2), the bellows tube (8)
Since it can be pulled out from the joint body (1) together with the tightening tube (2) and the retainer (3), various parts can be easily replaced. In the above embodiment, the retainer (3)
As a pressing portion for pressing the tapered outer peripheral surface (31) in the diameter reducing direction, a tapered inner peripheral surface (21) is formed at the front end of the body portion (23) of the tightening tube (2). The pressing portion is not limited to the tapered surface, and may be, for example, a configuration in which an annular convex portion is projected on the upper side wall on the rear side of the engaging concave portion (20).

[Brief description of drawings]

FIG. 1 is a partially cutaway sectional view showing a state in which a tightening cylinder and a bellows tube of a flexible pipe joint are positioned at a temporary fixing position in an embodiment of the present invention.

FIG. 2 is an enlarged sectional view of an essential part showing a state in which the tightening cylinder and the bellows tube of the flexible pipe joint are positioned at the temporary fixing position in the embodiment of the present invention.

FIG. 3 is a sectional view of a retainer used in the flexible pipe joint according to the embodiment of the present invention.

FIG. 4 is a view showing a state in which the tightening cylinder and the bellows tube of the flexible pipe joint according to the embodiment of the present invention are positioned at a temporary fixing position,
The principal part expanded sectional view which shows a mode that the force of the pull-out direction was applied to the said bellows tube.

FIG. 5 is a partially cutaway cross-sectional view showing a state in which the tightening cylinder of the flexible pipe joint according to the embodiment of the present invention is tightened to the final tightening position.

FIG. 6 is a cross-sectional view showing a state in which a bellows tube is inserted into a conventional flexible pipe joint before tightening.

FIG. 7 is a cross-sectional view after tightening showing a state in which a bellows tube is inserted into a conventional flexible pipe joint.

[Explanation of symbols]

(1) ・ ・ ・ Fitting body (11) ・ ・ ・ First female thread (12) ・ ・ ・ Second female thread (13) ・ ・ ・ No screw part (17) ・ ・ ・ Retainer housing cylinder (2) ... Tightening tube (3) ・ ・ ・ Retainer (8) ・ ・ ・ Bellows tube

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Totaro Horiguchi, 1 at 18 Hanana Kamitoba, Minami-ku, Kyoto City, Fujii Gokin Seisakusho Co., Ltd. (56) Reference JP-A-9-269091 Kaihei 11-248060 (JP, A) JP 10-292888 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) F16L 33/00 F16L 33/28

Claims (3)

(57) [Claims] 1. A tubular joint main body, a tightening cylinder that is inserted into the joint main body from the rear and positioned at a temporary fixing position in the joint main body, and is connected to a front end of the tightening cylinder. And an annular retainer, wherein the tightening cylinder holds the bellows tube in a temporarily fixed state at the temporary fixing position, the retainer is configured to be expandable and contractible in a radial direction, and the tightening cylinder is When tightened from the temporary fixing position to the final tightening position, it is pushed into the retainer accommodating cylinder part provided at the front end of the joint body while being fitted onto the bellows pipe, and its front end part is in the expansion preventing state. In the flexible pipe joint maintained as described above, a male screw portion is formed in a certain range on the outer periphery of the body of the tightening cylinder, and first and second females in which the male screw portion is screwed in the joint body. The screw part is provided on the front and back through the non-screw part In addition, the first female screw portion is formed near the rear open end of the joint body, the second female screw portion is formed near the retainer housing cylinder portion, and the inner diameter of the non-screw portion is It is set to be larger than the thread diameter of the male screw portion and its axial length is set to be longer than that of the male screw portion, and the retainer is capable of expanding in the second female screw portion. The tightening cylinder is positioned in the joint main body at the temporary fixing position by abutting the screw thread portion at the front end of the male screw portion on the rearmost screw thread portion of the second female screw. The flexible pipe joint, wherein the front end portion of the retainer is set so as to correspond to the second female screw portion. 2. The flexible pipe joint according to claim 1, wherein the retainer is formed such that a biting portion externally fitted to a trough portion of the bellows tube is protruded inward at the front end portion. A cylindrical body having a substantially C-shaped cross section is formed on the outer peripheral edge of the rear end portion of the tapered outer peripheral surface, and a small-diameter cylindrical portion is provided in front of the body portion of the tightening cylinder. It is formed to be extended, and the rear end portion of the retainer is externally fitted and connected to the small-diameter tubular portion so as to be movable in the front-back direction and in a retaining state, and the retainer is attached to the rear end of the small-diameter tubular portion. A flexible pipe joint in which a pressing portion that presses the tapered outer peripheral surface is formed on a front end surface of a body portion of the tightening cylinder that faces the tapered outer peripheral surface in a moved state. 3. The flexible pipe joint according to claim 2, wherein the pressing portion is a tapered inner peripheral surface formed so as to face the tapered outer peripheral surface.