JP2000110977A - Flexible pipe fitting - Google Patents

Abstract

PROBLEM TO BE SOLVED: To lessen the force required to screw in a fastening cylinder. SOLUTION: A flexible pipe fitting is equipped with a fitting body 1 in cylindrical form to admit insertion of a flexible pipe 8, a fastening cylinder 2 inserted in screwing from the pipe inserting side to the body part 1, and a lock ring 3 accommodated in the body part 1 in such a way as confronting the forefront face of the cylinder 2, wherein the ring 3 has such a taper as gradually enlarging diameterically in the inserting direction of the flexible pipe 8, and the body part 1 is equipped on the inside circumferential wall with a ring-shaped step 15 composed of a ring-shaped plane portion 15a confronting the forefront face of the cylinder 2 and a circumferential wall 15b continues to the peripheral surface of the plane portion 15a and to accommodate the ring 3 coaxially in the peripherally restrained condition. The inside diameter of the ring 3 is set greater than the outside diameter of the crests of the pipe 8 when the ring 3 is in free state and smaller than the outside diameter of the crests of the pipe 8 when the ring 3 is flattened in the peripherally restrained condition.

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 bellows-shaped flexible pipe having ridges and valleys alternately and continuously connected in parallel is connected. .

[0002]

2. Description of the Related Art FIG. 12 is a cross-sectional view of a conventional flexible pipe joint before screwing, and FIG. 13 is a cross-sectional view of the flexible pipe joint of FIG. 12 after screwing. The flexible pipe joint shown in FIG.
The above-mentioned flexible pipe (8) is connected, and a flexible pipe joint (9) for connecting the flexible pipe (8) is connected to the flexible pipe joint.
a), a tightening cylinder (9b) inserted and screwed into the joint main body (9a) with the flexible tube (8) inserted therethrough, and a tightening cylinder (9b) disposed in the joint main body (9a). Locking ring (9c) facing the tip
And are provided.

[0003] The locking ring (9c) is a C-shaped annular plate having an opening (not shown) formed at one location in the circumferential direction, and is provided on the inner surface of the joint main body (9a). The locking ring
A recess (90) for accommodating (9c) is formed. The front end face of the flexible tube (8) in the recess (90) in the insertion direction is a tapered surface (91) whose diameter is reduced in the insertion direction.

In this case, a flexible tube is attached to a locking ring (9c).
When the tightening tube (9b) is screwed in a state where (8) is inserted, the locking ring (9c) is pressed in the insertion direction by the tightening tube (9b) and pressed against the tapered surface (91). At this time, the diameter of the tapered surface (91) is reduced in the insertion direction, so that the locking ring (9c) is
The diameter is reduced while sliding in the axial direction with respect to (91). As a result, the inner peripheral portion of the locking ring (9c) enters the predetermined valley (89) of the flexible tube (8).

In this state, since the inner peripheral side portion of the locking ring (9c) enters the valley (89) of the flexible tube (8), the flexible tube
(8) is connected to this flexible pipe joint in a retaining state. In this case, the tightening cylinder (9
By further screwing in b), the crests (88) and the distal end portion of the flexible tube (8) as shown in FIG.
The airtight seal between the flexible tube (8) and the joint main body (9a) is ensured by closely contacting the annular packing (92) arranged on the joint main body (9a).

[0006]

However, in this case, when the fastening cylinder (9b) is screwed in, the locking ring (9c) is used.
Since the outer peripheral edge is reduced in diameter while sliding in the axial direction with respect to the tapered surface (91), the outer peripheral edge of the locking ring (9c) tends to bite into the tapered surface (91) during the sliding, This locking ring
(9c) does not easily move in the insertion direction. Therefore, the tightening cylinder (9
The force required for screwing in b) increases.

An object of the present invention is to reduce the force required for screwing a tightening cylinder. [1]

[0008]

Means for Solving the Problems The solution of the present invention taken to solve the above-mentioned problem is that "a bellows-like flexible tube in which peaks and valleys are alternately and continuously connected in parallel is connected. A flexible joint having a seal portion in contact with the distal end of the flexible tube on one side and the other end on the flexible tube insertion side inserted through the flexible tube. A tightening tube inserted and screwed into the flexible tube insertion side of the joint main body in a state where the joint main body is engaged, and a locking ring housed in the joint main body so as to face a distal end surface of the tightening tube. In accordance with the screwing of the tightening cylinder in a state where the flexible tube is inserted into the locking ring, the inner peripheral portion of the locking ring is reduced by the tightening cylinder and the joint main body, and the crest is formed. The flexible tube joint is configured to connect the flexible tube in a retaining state by engaging with the flexible tube. In the above, the locking ring is a tapered ring whose diameter gradually increases in the insertion direction of the flexible tube, and is closer to the tightening cylinder than the seal portion on the inner peripheral wall of the joint main body. An annular step formed of an annular flat surface facing the distal end surface of the tightening cylinder and a peripheral wall continuing from the outer periphery thereof and accommodating the engaging ring coaxially in an outer peripheral constrained state; The diameter is larger than the outer diameter of the crest when the locking ring is in the free state, and smaller than the outer diameter of the crest when the locking ring is flattened in the outer circumference restrained state. It is characterized by being set to such a diameter.

In this case, since the inner diameter of the locking ring in the free state is larger than the outer diameter of the ridge of the flexible tube, the locking ring must be flexible before the screwing of the tightening tube. A tube can be inserted. The locking ring may be housed in the annular step in advance. Then, when the tightening cylinder is screwed in this inserted state, the locking ring is compressed in the axial direction by the distal end surface of the tightening cylinder and the annular step portion mainly composed of the joint in an outer peripheral constrained state. As a result, the cross section of the locking ring is deformed so as to rotate around its outer peripheral end. That is, the diameter of the inner ring of the locking ring is reduced while moving toward the distal end of the flexible tube.

[0010] Finally, the locking ring is maintained in a flattened state by the distal end surface of the tightening cylinder and the annular flat portion, and in this flattened state, the inner diameter of the locking ring is reduced to the outer circumference of the peak portion. Since the diameter is smaller than the diameter, the inner peripheral portion of the locking ring enters the valley of the flexible tube. Therefore, the flexible tube is engaged with the locking ring in a retaining state.

[0011]

According to the present invention, as described above, in the process of reducing the inner peripheral portion of the locking ring by screwing the tightening cylinder, the cross section of the locking ring rotates around its outer peripheral end. Since the locking ring is deformed, the locking ring is smoothly deformed during the reduction process. Therefore, the force required for screwing the tightening cylinder is reduced.

[2] The method according to the above [1], wherein the locking ring has an open portion formed at one position in a circumferential direction thereof and a plurality of cut portions cut from an outer peripheral edge thereof and arranged in the circumferential direction. And a notch. In this case, since the opening is formed at one position in the circumferential direction of the locking ring, the locking ring is easily compressed in the axial direction when the tightening cylinder is screwed. Therefore, also in this respect, the force required for screwing the tightening cylinder is reduced.

Further, since the locking ring has a plurality of notches cut from the outer peripheral edge thereof and arranged in the circumferential direction, the locking ring is easily compressed in the axial direction when the tightening cylinder is screwed in also at this point. In addition, the force required for screwing the tightening cylinder is further reduced. [3] The method according to the above [1] or [2], further comprising an auxiliary ring axially superimposed on the locking ring, wherein the auxiliary ring has an apparent inner diameter smaller than that of the crest. And the inner diameter is expanded so as to be elastically restored by forcible pushing of the flexible tube ”.

In this structure, when inserting the flexible tube into the locking ring, if the flexible tube is forcibly pushed into the auxiliary ring superimposed on the locking ring, the pushing causes the apparent appearance of the auxiliary ring. The inner diameter is enlarged and the flexible tube is inserted. Since the auxiliary ring is elastically resilient, the crest of the flexible tube is engaged with the auxiliary ring, whereby the flexible tube is temporarily fixed to the flexible tube joint. .

Therefore, before screwing the tightening cylinder,
The flexible tube cannot be accidentally pulled out of the flexible tube joint. The apparent inner diameter of the auxiliary ring is the diameter of an imaginary circle inscribed in the tip group of the protrusions when a plurality of protrusions protrude inward from the inner periphery of the ring-shaped main body.
The auxiliary ring includes a ring in which only the convex portion is partially elastically deformed, a ring in which the ring-shaped main portion is expanded and deformed, and a ring in which both are deformed.

[4] The method according to the above [3], wherein the auxiliary ring is formed of an elastic plate, and a ring-shaped main portion overlapped with the locking ring on the tightening cylinder side;
A plurality of engaging pieces extending gradually from the inner peripheral edge of the ring-shaped main body toward the insertion direction toward the inner peripheral side, and the diameter of an imaginary circle connecting the tips of the engaging pieces is the outer diameter of the crest. The auxiliary ring is an elastic plate, and a plurality of engaging pieces gradually extend from the inner peripheral edge of the ring-shaped main body toward the inner side in the insertion direction. It has a configuration. The diameter of the virtual circle connecting the tips of the engagement pieces is set smaller than the outer diameter of the peak of the flexible tube.

Therefore, when the flexible tube is pushed into the ring-shaped main portion, the engaging piece group rides over the peak portion of the flexible tube so as to be elastically deformed toward the outer periphery and then elastically deformed toward the inner periphery. Thus, the flexible tube is inserted through the locking ring and the auxiliary ring. Then, when the flexible tube is pulled in the removal direction in this inserted state, the ridges of the flexible tube are engaged with the group of engagement pieces in a contact state, and the flexible tube is temporarily held by the auxiliary ring. It will be stopped.

In this case, the ring-shaped main portion of the auxiliary ring is superposed on the locking ring from the side of the tightening cylinder, and is not located between the locking ring and the annular flat portion. It does not hinder the compression deformation of the retaining ring. [5] The method according to the above [3], wherein the auxiliary ring is formed of a tapered elastic plate which is superimposed on the annular flat surface side with respect to the locking ring and gradually increases in diameter toward the annular flat surface portion. And a ring-shaped main body having one opening in the circumferential direction, and a plurality of engagement protrusions provided on an inner peripheral edge of the ring-shaped main body, and a virtual circle connecting the tips of the engagement protrusions. In this configuration, the diameter of the auxiliary ring is set smaller than the outer diameter of the ridge portion. The diameter of a virtual circle connecting the tips of the engagement protrusions is set to be smaller than the outer diameter of the ridge of the flexible tube.

Therefore, when the flexible tube is pushed into the ring-shaped main portion, the ring-shaped main portion is elastically deformed to the outer peripheral side and then elastically deformed to the inner peripheral side, so that the engaging projections climb over the peak portion. . Thus, the flexible tube is inserted through the locking ring and the auxiliary ring. When the flexible tube is pulled in the pull-out direction in this inserted state, the engagement protrusion and the crest come into contact in the axial direction, so that the ring-shaped main portion slides on the locking ring to reduce the diameter. I do.
As a result, the engaging projections tend to bite into the ridges, the ridges of the flexible tube engage with the engaging projections, and the flexible tube is temporarily fixed by the auxiliary ring.

In this structure, the ring-shaped main portion is overlapped on the locking ring from the annular flat portion side. The ring-shaped main portion has a tapered elasticity whose diameter gradually increases toward the annular flat portion. Since the plate is a plate, the auxiliary ring does not easily interfere with the compression deformation of the locking ring.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described.
This will be described with reference to the drawings. FIG. 1 is a cross-sectional view of a flexible pipe joint according to an embodiment of the present invention. FIG. 2 is an enlarged view of a main part of the flexible pipe joint of FIG. FIG. 3 is an enlarged view of a main part of the flexible pipe joint of FIG. 1 after screwing of the tightening cylinder (2). And FIG.
5 is a front view of the locking ring (3) of FIG. 1, and FIG. 5 is a cross-sectional view of the locking ring (3) of FIG. FIG.
7 is a front view of the auxiliary ring (4) of FIG. 1, and FIG. 7 is a sectional view of the auxiliary ring (4) of FIG. 6 along the line VII-VII.

As shown in FIG. 1, this flexible pipe joint comprises a tubular joint main body (1) into which a flexible pipe (8) is inserted, and a flexible pipe (1).
(8) and a tightening cylinder (2) which is inserted and screwed into the flexible tube insertion side of the joint main body (1), and this tightening cylinder
A locking ring (3) housed in the joint body (1) so as to face the distal end surface of (2), and an auxiliary ring superimposed on this locking ring (3) from the tightening cylinder (2) side A ring (4).

The flexible tube (8) has a bellows shape in which peaks and valleys are alternately and continuously arranged in parallel, and the distal end of the flexible tube (8) is located at the deepest portion of the valley. Has become. [Configuration of each part] * Joint main body (1) * The above-mentioned joint main body (1) includes a screw cylinder section (11) for connection with gas appliances and the like, as shown in FIG. 1
The flexible tube (8) is inserted from the side opposite to 1). As shown in FIGS. 1 and 2, a female screw portion (12) is provided on the inner peripheral wall of the flexible tube insertion side portion of the joint main body (1).
The inner diameter of the female screw portion (12) is set to be larger than the diameter of the flow passage hole (14) in the screw tube portion (11).

And, on the inner peripheral wall of the joint main body (1),
As shown in FIGS. 1 and 2, an annular end face which is located on the outer peripheral side of the inner end of the flow passage hole (14) and in which the tip of the flexible tube (8) abuts.
(17) is formed, and further on the outer peripheral side, this annular end face
(17) on the side of the tightening cylinder (2)
An annular plane portion (15a) that is perpendicular to the axial direction and that faces 2) is formed.

An annular groove (18) is formed in the inner peripheral portion of the annular flat portion (15a) so as to be continuous with the annular end surface (17). An annular packing (13) for ensuring airtightness with the tip of the flexible tube (8) is accommodated. Accordingly, the annular packing (13) is exposed on the side of the annular end face (17) (the inner peripheral side). Furthermore, this joint main body (1)
A peripheral wall (15b) connected to the female screw part (12) is formed on the inner peripheral wall of the inner peripheral wall following the outer periphery of the annular planar part (15a), and the peripheral wall (15b) and the annular planar part (15a) are formed. It constitutes an annular step (15). The diameter of the peripheral wall (15b) is set to such a size that a locking ring (3) to be described later is just fitted therein. Therefore, a locking ring is attached to this annular step (15).
When (3) is fitted, the locking ring (3)
Are housed coaxially with the outer periphery constrained.

The flexible tube insertion side of the joint body (1)
It is a tool corresponding part (10) having a polygonal cross section. * Tightening tube (2) * As shown in FIGS. 1 and 2, the above-mentioned tightening tube (2) has a male screw portion (21) screwed into the female screw portion (12) in the middle of the axial direction. ) In the screwing direction of the tightening cylinder (2), and a portion on the tip end side of the male screw portion (21) is set to a size that just fits into the above-mentioned peripheral wall portion (15b).

The rear end of the tightening cylinder (2) in the screwing direction is a tool corresponding portion (20) having a polygonal cross section that protrudes outward from the front portion thereof. Two
An annular packing (23) for securing airtightness with the joint main body (1) in a state where the tightening cylinder (2) is screwed most is mounted on the front end face portion of (0). An inner peripheral portion of the tool corresponding portion (20) has an annular shape having a convex cross section for ensuring airtightness with a synthetic resin covering tube (80) covering the flexible tube (8). Packing (25) is attached. This packing
(25) prevents infiltration of rainwater or the like into the joint main body (1) when the flexible tube (8) is connected.

Further, the tightening cylinder (2) has a male thread portion (2
An annular plate projecting to the outer peripheral side between 1) and the tool counterpart (20)
(24) is connected and integrated. The annular plate (24) enters and engages with an annular step (16) recessed from the end face on the flexible tube insertion side of the joint main body (1) before screwing the tightening cylinder (2). In this engagement state, the valley (81) adjacent to the rear end of the foremost ridge (82) of the flexible tube (8) with the flexible tube (8) in contact with the annular end face (17). The locking ring (3) and the auxiliary ring (4) are formed so that the inner peripheral portions of the locking ring (3) and the auxiliary ring (4) described later
(22).

* Locking ring (3) * As shown in FIGS. 4 and 5, the locking ring (3) is made of a metal whose diameter gradually increases in the insertion direction of the flexible tube (8). The inner diameter of the locking ring (3) is a flexible tube when the locking ring (3) is in a free state.
When the locking ring (3) is larger than the outer diameter of the ridge of (8) and the locking ring (3) is compressed and flattened in the axial direction in the state of the outer circumference restrained by the annular step (15), the flexible tube (8) Is set to be smaller than the outer diameter of the peak portion.

The locking ring (3) has an open portion (31) formed at one location in the circumferential direction and a plurality of notches (32) cut from the outer peripheral edge and lined up in the circumferential direction. ) And are provided. * Auxiliary ring (4) * The above-mentioned auxiliary ring (4) is made of a leaf spring, and as shown in FIGS. 2, 6 and 7, the tightening cylinder (2) side with respect to the locking ring (3). Ring-shaped main part superimposed from metal
(40) and a plurality of metal engaging pieces (41) projecting from the inner peripheral edge of the ring-shaped main body (40) and arranged in the circumferential direction. Incidentally, as long as the auxiliary ring (4) is an elastic body,
For example, it may be made of a hard synthetic resin.

The auxiliary ring (4) has a tapered shape whose diameter is reduced in the insertion direction as a whole, and each engagement piece (41) is formed of a ring-shaped main portion (40). It extends gradually from the inner peripheral edge toward the inner peripheral side in the insertion direction. The distal end portion of each engagement piece (41) is located near the inner peripheral edge of the locking ring (3). The diameter of the virtual circle (48) connecting the tips of the engagement pieces (41) is set smaller than the outer diameter of the ridge of the flexible tube (8).

[Use of Flexible Pipe Joint] When using this flexible pipe joint, first, as shown in FIGS. 1 and 2, the flexible pipe (8) is fastened to the tightening cylinder (2) and the joint body ( Insert into 1). At this time, since the inner diameter of the locking ring (3) in the free state is larger than the outer diameter of the crest of the flexible tube (8), the flexible ring (8) is attached to the locking ring (3). ) Can be inserted.

At this time, as described above, the locking ring
The ring-shaped main part (40) of the auxiliary ring (4) is overlapped from the side of the tightening cylinder (2) with respect to (3), and the engagement piece () protruding from the inner peripheral edge of the ring-shaped main part (40) 41) is an elastic plate that gradually extends toward the inner peripheral side in the insertion direction.
The diameter of the virtual circle (48) connecting the tips of the engagement pieces (41) is set smaller than the outer diameter of the ridge of the flexible tube (8).

Therefore, the flexible tube (8) is attached to the ring-shaped main portion (40).
When the fork is forcibly pushed, each engaging piece (41) climbs over the foremost peak (82) of the flexible tube (8) so that it is elastically deformed to the outer periphery and then elastically deformed to the inner periphery. Becomes As a result, the flexible tube (8) is inserted through the locking ring (3) and the auxiliary ring (4). In this insertion state, the flexible tube (8)
The tip portion (82) of the above is engaged with the engagement piece (41), and the flexible tube (8) is temporarily fixed by the auxiliary ring (4).

In this inserted state, the flexible tube (8) comes into contact with the annular end face (17), and as described above,
Lock ring on valley (81) adjacent to ridge (82) of flexible tube (8)
(3) and the inner peripheral part of the auxiliary ring (4).
After this, the tool corresponding part (10) of the joint main body (1) and the tightening cylinder (2)
When the tightening cylinder (2) is screwed into the joint body (1) while holding the tool counterpart (20) with a spanner, etc.,
From (2), the annular plate (24) breaks in the axial direction. With this screwing, the locking ring (3) is axially compressed by the annular step portion (15) of the joint main body (1) and the distal end surface (22) of the tightening cylinder (2) in the outer peripheral constrained state. You. At the same time, the auxiliary ring (4)
Are also compressed in the axial direction.

At this time, the outer peripheral end of the cross section of the locking ring (3) is in contact with the corner of the annular step (15) (the boundary between the annular plane (15a) and the peripheral wall (15b)). This locking ring
The cross section of (3) is compressed and deformed so as to rotate around the outer peripheral end. That is, the diameter of the inner peripheral portion of the locking ring (3) is reduced while moving toward the distal end of the flexible tube (8).

Finally, the locking ring (3) is flattened at right angles to the axial direction by the end surface (22) of the tightening cylinder (2) and the annular flat portion (15a). Become. At this time, the inner diameter of the locking ring (3) in the flattened state is a flexible tube (8).
Since the outer diameter of the ridge is smaller than the outer diameter of the ridge, the inner circumference of the locking ring (3) is formed at the valley of the flexible tube (8) with the flattening.
(82). Therefore, in the flattened state, as shown in FIG. 3, the flexible tube (8) is engaged with the locking ring (3) in a retaining state.

In the final stage of the flattening, a flexible tube
The peak (82) of (8) is compressed in the axial direction, and the outer
While expanding to the (18) side, the annular packing (13) is also compressed in the axial direction, and its inner peripheral portion is reduced. As a result, the outer peripheral portion of the peak portion (82) and the annular packing (13) are brought into close contact with each other in the circumferential direction, and airtightness between the two is ensured.

It is to be noted that, depending on the configuration of these parts, the flexible tube
The annular flat portion (15a) is located closer to the tightening cylinder (2) than the seal portion (the contact portion between the outer peripheral portion of the peak portion (82) and the annular packing (13)) that contacts the tip of (8). Becomes In this case, as described above, when the inner peripheral portion of the locking ring (3) is reduced by screwing the tightening cylinder (2), the locking ring is used.
Since the cross section of (3) is deformed so as to rotate around its outer peripheral end, the deformation of the locking ring (3) during this reduction process becomes smooth. Therefore, the force required for screwing the tightening cylinder (2) is reduced.

Further, since an opening (31) is formed at one location in the circumferential direction of the locking ring (3), the locking ring (3) is compressed in the axial direction when the tightening cylinder (2) is screwed. Easy to do. Therefore, also in this respect, the force required for screwing the tightening cylinder (2) is reduced. Further, since the locking ring (3) is provided with a plurality of notches (32) cut from the outer peripheral edge thereof and arranged in a circumferential direction, the locking ring (3) is also provided with the shaft in this respect. Direction, and the force required for screwing the tightening cylinder (2) is further reduced.

In this device, when the flexible tube (8) is inserted through the locking ring (3) and the auxiliary ring (4), the peak (82) of the flexible tube (8) is engaged with the engaging piece. Since the flexible tube (8) is temporarily fixed by the auxiliary ring (4) by engaging with the (41), the flexible tube joint can be removed from the flexible tube joint before screwing the tightening cylinder (2). The flexible tube (8) cannot be accidentally pulled out. or,
The tip of the engagement piece (41) of the auxiliary ring (4) is the locking ring.
(3), the engaging piece (41) and the inner peripheral portion of the locking ring (3) face the common valley (81) in the temporarily fixed state. Becomes Therefore, due to the subsequent compression of the locking ring (3), the inner peripheral portion of the locking ring (3) has a valley portion.
Enter (81) without fail.

In this embodiment, the auxiliary ring (4) is superposed on the locking ring (3) from the side of the tightening cylinder (2), and is provided between the locking ring (3) and the annular flat portion (15a). Therefore, the auxiliary ring (4) does not hinder the compression deformation of the locking ring (3). Furthermore, the notch (32) of the locking ring (3)
Since the notch (32) is not cut from the inner peripheral edge of the locking ring (3), the ridge of the flexible tube (8) is cut off from the outer peripheral edge of the locking ring (3). Locking ring to engage
The strength of the inner peripheral part of (3) is secured. [Other embodiments]. FIG. 8 is an enlarged view of a main part of a flexible pipe joint according to another embodiment of the present invention before screwing a tightening cylinder (2).
FIG. 9 is an enlarged view of a main part of the flexible pipe joint shown in FIG. 8 after the tightening cylinder (2) is screwed. FIG. 10 is a front view of the auxiliary ring (5) of FIG. 8, and FIG. 11 is a sectional view of the auxiliary ring (5) of FIG. 10 taken along the line XI-XI.

In this embodiment, only the auxiliary ring (4) of the above embodiment is changed to an auxiliary ring (5) shown in FIGS. This auxiliary ring (5)
As shown in FIGS. 8, 10 and 11, the locking ring (3)
A ring-shaped main portion (50) made of an elastic plate superposed from the annular flat portion (15a) side, and the ring-shaped main portion (5
A) a plurality of engaging projections projecting from the inner peripheral edge of
(51).

The ring-shaped main portion (50) has a tapered shape whose diameter gradually increases toward the annular flat portion (15a). An opening (52) is formed, and a plurality of cutouts (53) cut from the outer peripheral edge and arranged in the circumferential direction are provided.
The engagement projections (51) protrude in an edge shape from the inner peripheral edge of the ring-shaped main body (50). The diameter of the imaginary circle (58) to be connected is set to be smaller than the outer diameter of the ridge of the flexible tube (8).

In this device, by pushing the flexible tube (8) into the ring-shaped main portion (50), the ring-shaped main portion (50) is elastically deformed to the outer peripheral side and then elastically deformed to the inner peripheral side. The engaging projection (51) goes over the ridge (82) of the flexible tube (8), and thereby the locking ring (3) and the auxiliary ring
The flexible tube (8) is inserted through (5). In this insertion state, when the flexible tube (8) is pulled in the pull-out direction, the engagement protrusion (51) and the peak (82) abut in the axial direction.
The diameter of the ring-shaped main body (50) is reduced while sliding on the locking ring (3). As a result, the engaging projection (51) tends to bite into the slope of the peak (82), and this peak (82)
1), this auxiliary ring (5) allows the flexible tube
(8) is temporarily fixed.

When the tightening cylinder (2) is screwed in this inserted state, the locking ring (3) and the auxiliary ring (5) are compressed in the axial direction in the same manner as in the above-described embodiment.
As shown in FIG. 9, the locking ring (3) and the auxiliary ring (5)
Is flattened. Also, due to this flattening,
In the same manner as in the above-described embodiment, the ridges (8
2) and the annular packing (13) are tightly adhered in an airtight state.

In this embodiment, the ring-shaped main portion (50) is overlapped with the locking ring (3) from the side of the annular flat portion (15a). Department (1
Since it is a tapered annular plate whose diameter gradually increases toward 5a), the auxiliary ring (5) is unlikely to hinder the compression deformation of the locking ring (3). In this one, the auxiliary ring
Since the opening (52) is formed at one location in the circumferential direction of (5), the auxiliary ring (5) is easily compressed in the axial direction when the tightening cylinder (2) is screwed. Therefore, also in this respect, the tightening cylinder (2)
The force required for screwing is reduced.

Since the auxiliary ring (5) has a plurality of cutouts (53) cut from the outer peripheral edge thereof and arranged in the circumferential direction, the auxiliary ring (5) is also compressed in the axial direction at this point. The force required for screwing the tightening cylinder (2) is further reduced. . In the above embodiment, the locking ring (3) is
(31) and notch (32)
As long as it is compressed in the axial direction by the screwing in (2), a configuration without these open portions (31) and notches (32) may be adopted.

[0049] In the above embodiment, the locking ring
In (3), the structure is flattened from the initial taper shape to a direction perpendicular to the axial direction by axial compression. However, the structure may be flattened to an intermediate position.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a flexible pipe joint according to an embodiment of the present invention.

FIG. 2 is an enlarged view of a main part before screwing of a tightening cylinder (2) in the flexible fitting of FIG. 1;

FIG. 3 is an enlarged view of a main part of the flexible pipe joint of FIG. 1 after screwing of the tightening cylinder (2).

FIG. 4 is a front view of the locking ring (3) of FIG. 1;

FIG. 5 is a sectional view taken along line VV of the locking ring (3) in FIG. 4;

FIG. 6 is a front view of the auxiliary ring (4) in FIG. 1;

FIG. 7 is a sectional view taken along line VII-VII of the auxiliary ring (4) in FIG. 6;

FIG. 8 is an enlarged view of a main part of a flexible pipe joint according to another embodiment of the present invention before screwing of a tightening cylinder (2).

FIG. 9 is an enlarged view of a main part of the flexible pipe joint of FIG. 8 after screwing of the tightening cylinder (2).

FIG. 10 is a front view of the auxiliary ring (5) in FIG. 8;

FIG. 11 is a sectional view taken along the line XI-XI of the auxiliary ring (5) in FIG. 10;

FIG. 12 is a sectional view of a conventional flexible pipe joint before screwing.

FIG. 13 is a sectional view of the flexible pipe joint of FIG. 12 after screwing;

[Explanation of symbols]

 (1) ・ ・ ・ Joint body (2) ・ ・ ・ Tightening cylinder (3) ・ ・ ・ Locking ring (4) ・ ・ ・ Auxiliary ring (15) ・ ・ ・ Annular step (15a) ・ ・ ・ Annular plane Part (15b) ・ ・ ・ Peripheral wall part

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] July 19, 1999 (1999.7.1)
9)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claim 1

[Correction method] Change

[Correction contents]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0008

[Correction method] Change

[Correction contents]

[0008]

Means for Solving the Problems The solution of the present invention taken to solve the above-mentioned problem is that "a bellows-like flexible tube in which peaks and valleys are alternately and continuously connected in parallel is connected. A flexible tube coupling having a seal portion in contact with the distal end portion of the flexible tube inside one of the flexible tubes and the other having a flexible tube insertion portion on the flexible tube insertion side. A joint main body, a tightening cylinder inserted and screwed into the flexible tube insertion side of the joint main body with the flexible tube inserted therein, and a joint main body inside the joint main body facing the distal end surface of the tightening cylinder. A locking ring accommodated therein, and with the screwing of the tightening cylinder in a state where the flexible tube is inserted through the locking ring, the tightening cylinder and the joint main body form the locking ring. A state in which the flexible tube is prevented from being pulled out by reducing the inner peripheral portion and engaging with the peak portion. In the flexible pipe joint configured to be connected, the locking ring is a tapered ring whose diameter gradually increases in the insertion direction of the flexible pipe, and is formed by a sealing portion on an inner peripheral wall of the joint main body. Also, on the side of the tightening cylinder, there is formed an annular step portion comprising an annular flat portion facing the distal end surface of the tightening cylinder and a peripheral wall portion following the outer periphery thereof, and accommodating the locking ring coaxially in an outer peripheral constrained state. The inner diameter of the locking ring is larger than the outer diameter of the ridge when the locking ring is in a free state, and the inner diameter is smaller when the locking ring is flattened in the outer circumference restricted state. The diameter is set so as to be smaller than the outer diameter of the ridge. "

Claims (5)

[Claims] 1. A flexible pipe joint to which a bellows-shaped flexible tube in which a peak portion and a valley portion are alternately and continuously connected in parallel is connected, and a seal portion which is in contact with a tip portion of the flexible tube is provided. A tubular joint main body that is provided on one side and the other is the flexible tube insertion side, and a tightening cylinder inserted and screwed into the flexible tube insertion side of the joint main body with the flexible tube inserted therethrough And a locking ring housed in the joint main body so as to face the distal end surface of the tightening cylinder, and screwing the tightening cylinder in a state where the flexible tube is inserted through the locking ring. Accordingly, the flexible tube is connected in a retaining state by reducing an inner peripheral portion of the locking ring by the tightening cylinder and the joint main body and engaging the locking ring with the ridge portion. In the pipe joint, the locking ring gradually increases in diameter in a direction in which the flexible tube is inserted. That tapers ring, the clamping cylinder side than at the seal portion on the inner peripheral wall of the joint entity,
An annular step is formed which comprises an annular flat portion facing the distal end surface of the tightening cylinder and a peripheral wall portion following the outer periphery thereof, and which coaxially accommodates the locking ring in an outer circumferentially constrained state. The circumferential diameter is larger than the outer diameter of the crest when the locking ring is in a free state, and smaller than the outer diameter of the crest when the locking ring is flattened in the outer circumferential constrained state. A flexible pipe joint characterized by being set to have such a diameter. 2. The locking ring according to claim 1, further comprising: an opening formed at one location in a circumferential direction thereof; and a plurality of cutouts cut from an outer peripheral edge thereof and arranged in the circumferential direction. 4. The flexible pipe joint according to claim 1. 3. An auxiliary ring axially superimposed on said locking ring, said auxiliary ring having an apparent inner diameter smaller than said crest and forcing said flexible tube. The flexible pipe joint according to claim 1, wherein the inner diameter is expanded so that the inner diameter can be elastically restored by a proper pushing. 4. The auxiliary ring is made of an elastic plate, and has a ring-shaped main portion superposed on the locking cylinder side with respect to the locking ring, and an inner peripheral edge of the ring-shaped main portion in the insertion direction. And a plurality of engagement pieces that gradually extend toward the inner peripheral side, wherein a diameter of an imaginary circle connecting the tips of the engagement pieces is set to be smaller than an outer diameter of the crest. The flexible pipe joint as described in the above. 5. The auxiliary ring is formed of a tapered elastic plate which is superimposed on the locking flat portion on the side of the annular flat portion and gradually increases in diameter toward the annular flat portion. , And a plurality of engagement protrusions provided on an inner peripheral edge of the ring-shaped main portion. The diameter of an imaginary circle connecting the tips of the engagement protrusions is the outer periphery of the peak portion. The flexible pipe joint according to claim 3, wherein the flexible pipe joint is configured to be smaller than the diameter.