JPH0218395Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a bellows-shaped flexible pipe joint with a corrugated longitudinal section.

A certain prior art will be described with reference to FIG.
In this prior art, a bellows-shaped metal flexible tube 41
An engaging collar 42 is formed by crushing one peak at the end of the flexible tube 41, and a sleeve 43 that engages with the engaging collar 42 is provided on the outer periphery of the flexible tube 41. A nipple 45 is butted against the end of the flexible tube 41 via a sealing member 44, and by screwing a cap nut 46 to the nipple 45, the sleeve 43 is pressed toward the nipple 45, thereby sealing. has been achieved.

In this prior art, it is necessary to compress and flatten one peak at the end of the flexible tube 41 using a jig in advance, which is a cumbersome task. Moreover, the sleeve 43 and the flexible tube 41 are engaged only by the engagement collar 42 formed by crushing one peak. Therefore, when a force is applied to the flexible tube 41 in the direction of separating it from the nipple 43, the engaging flange 4
2 may be bent, and the engagement between the engagement collar 42 and the sleeve 43 may be disengaged, and the flexible tube 41 may fall out.

FIG. 2 is a partially cutaway sectional view of another prior art. In this prior art, a plurality of ridges 48 are compressed and crushed from the end of a metal flexible tube 47 in the tube axis direction, and a cap nut 49 is engaged with the crushed ridges 48.
is provided on the outer periphery of the flexible tube 47. A joint portion 51 is butted against the end of the flexible tube 47 via a sealing member 50, and by screwing the cap nut 49 into the joint portion 51, the flexible tube 47 and the joint portion 51 are sealed. They are pressed together via member 50, thereby achieving a seal.

In this prior art, it is necessary to press and crush the plurality of peaks 48 using a jig in advance, similar to the prior art shown in FIG. 1, and the work for this is troublesome.
Further, the amount of protrusion along the radial direction of the plurality of collapsed peaks 48 is small compared to other peaks that are not crushed, and therefore the cap nut 49 and the peaks 48 are engaged with each other in an extremely small portion. It just matches,
There is a risk that the engagement may come off with a slight force.

FIG. 3 is a partially cutaway sectional view showing a prior art pipe joint for a helical flexible tube. In this prior art, a nipple 53 is screwed onto the inner periphery of the end of a helical flexible tube 52, and a sleeve 54 is screwed onto the outer periphery of the end of the flexible tube 52. Then, the sleeve 54 is pressed against the nipple 53 by the cap nut 55 to achieve a seal. In this prior art, as described above, it is necessary to rotate either the nipple 53 or the flexible tube 52 around the axis and screw them together, making the connection work cumbersome.

The purpose of the present invention is to solve the above-mentioned technical problems and provide a pipe joint that is easy to connect, reliably prevents the flexible pipe from coming out, and has improved sealing performance. .

The present invention is a pipe joint for a bellows-shaped flexible pipe 11 in which peaks and valleys are formed in an endless ring shape. The flexible tube 11 has an uneven portion 16 that fits snugly into the peaks and valleys on the outer circumference of the flexible tube 11 at least one pitch inward from the end thereof in the axial direction, and the outer shape is in a straight line in the axial direction. Sleeves 12 and 21 having uniform circular shapes; An annular sealing member 14 that abuts the end surface of the end portion 17 of the flexible tube 11 protruding from the sleeves 12 and 21; and Sleeve 12 of the flexible tube 11. , a fitting hole 18 into which the end portion 17 protruding from the bottom 13b is fitted and housed, and into which the sealing member 14 is fitted into the bottom 13b; It has an axial hole 13c that is smaller in diameter than 18 and that transports fluid, and has an external thread 19 on the outer periphery,
The end surface 13a includes a joint portion 13 that is in contact with one end surface 12d of the sleeves 12 and 21, and a cap nut 15 that has an external thread 1 of the joint portion 13.
9, and the sleeves 12 and 21, which are connected from the inner screw 20 via the step surface 15b and have a smaller diameter than the internal screw 20, are fitted into the sleeve 1.
A fitting hole 15c having the same length as 2 and 21,
An insertion hole 15 that extends from the fitting hole 15c via a stepped pressing surface 15a and has a diameter smaller than that of the fitting hole 15c, through which the flexible tube is inserted at intervals in the radial direction.
d in this order in the axial direction, and the stepped surface 15
b is in contact with the end surface 13a of the joint portion 13, and the pressing surface 15a is in contact with the other end surface 12c of the sleeve 12.
The end portion 17 of the flexible tube 11 protruding from the sleeves 12 and 21 becomes a sealing member by screwing the outer thread 19 and the inner thread 20 together. 14 and sleeve 1
This pipe joint is characterized in that it is compressed and collapsed in the axial direction between the one end surface 12d of the pipe joints 2 and 21.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 4 is a sectional view of an embodiment of the present invention,
A pipe fitting for a bellows-shaped flexible pipe is shown. This pipe joint includes a sleeve 12 fixed to the outer periphery of a metal flexible pipe 11, a nipple 13 as a joint part that is butted against and connected to the end of the flexible pipe 11, and the flexible pipe 11 and the nipple. It includes an annular seal member 14 interposed between the sleeve 12 and the nipple 13, and a cap nut 15 for fixing the sleeve 12 and the nipple 13 in close proximity until they abut.

FIG. 5 is a perspective view of the sleeve 12. The sleeve 12 consists of a pair of half pieces 12a and 12b. The inner periphery of each of the half pieces 12a, 12b is formed with an uneven portion 16 that fits snugly into the peaks and valleys of the outer periphery of the flexible tube 11. Half piece 12
When the half pieces 12a and 12b are attached to the outer periphery of the flexible tube 11, the circumferential ends of the half pieces 12a and 12b are brought into close contact with each other to form the cylindrical sleeve 12.
This sleeve 12 is fixed to the outer periphery of the flexible tube 11 at least one pitch (three pitches in the drawing) inward from the end of the flexible tube 11 along the axial direction.

A fitting hole 18 is formed at the end of the nipple 13 into which the end of the flexible tube 11 is fitted. A sealing member 14 is fitted into the bottom of this fitting hole 18,
The flexible tube 11 is fitted with the sealing member.
is inserted into the fitting hole 18. Nipple 13
An external thread 19 is carved on the outer periphery of the end portion.

The cap nut 15 is attached to the outer periphery of the flexible tube 11 so as to be movable in the axial direction. bag nut 15
A pressing surface 15a that comes into contact with an end surface 12c of the sleeve 12 on the side opposite to the nipple 13 is formed on the sleeve 12. Also, nipple 1 of bag nut 15
On the inner periphery of the end near 3, there is an external thread 1 of the nipple 13.
An internal thread 20 is formed which is threaded into 9 . The flexible tube 11 is bellows-shaped, and has peaks and valleys formed in an endless ring shape. The sleeves 12 and 21 are divided in the circumferential direction. This sleeve 12, 21
is a circular shape whose outer diameter is uniform in the axial direction. The end portions of the flexible tube 11 protruding from the sleeves 12, 21 are fitted into the fitting hole 18 of the nipple 13, which is a joint portion, and the seal member 14 is fitted into the bottom thereof. Fukuronatsu 15 has
Sleeves 12 and 21 are fitted together. Sleeve 21
This will be explained in conjunction with FIG. 6, which will be described later.

The shaft hole 13c formed in the joint part 13 is connected to the fitting hole 18 via the bottom 13b, and the fitting hole 18
It has a smaller diameter and transports fluids.

Fitting hole 15c formed in cap nut 15
is connected to the inner thread 20 via the stepped surface 15b, has a smaller diameter than the inner thread 20, and has a diameter smaller than that of the inner thread 20, and
are fitted, and have the same length as sleeve 12 and sleeve 21, which will be described later. Also, the insertion hole 1
5d is a stepped pressing surface 1 from the fitting hole 15c.
5a, the diameter of which is smaller than that of the fitting hole 15c, and the flexible tube 11 is inserted therethrough at intervals in the radial direction. The internal thread 20, the fitting hole 15c, and the insertion hole 15d are formed in this order in the axial direction.

In the pipe joint configured in this way, when the cap nut 15 is screwed onto the nipple 13, the sleeve 1
2 is pressed by the pressing surface 15a and the nipple 13
be close to. Since the sleeve 12 is tightly attached to the ridges on the outer periphery of the flexible tube 11, the end of the flexible tube 11 is pressed against the bottom of the fitting hole 18 in response to the movement of the sleeve 12. It will be done. Then, the cap nut 15 is screwed until the end surface 12d of the sleeve 12 opposite to the end surface 12c comes into contact with the end surface 13a of the nipple 13. Then,
In the flexible tube 11, the three peaks from the position where the sleeve 12 is attached to the end are compressed in the axial direction and collapsed to form the locking portion 17. This locking portion 17 is formed by crushing three peaks, so it has high steel properties. Therefore, even if a force is applied to the flexible tube 11 in the direction of separating it from the nipple 13,
The locking portion 17 does not bend, and therefore the locking portion 17 and the sleeve 12 are never disengaged. Therefore, the flexible pipe 11 is prevented from coming off from the pipe joint.

Further, by screwing the cap nut 15, the sealing member 14 is compressed between the bottom of the fitting hole 18 and the end of the flexible tube 11, so that the sealing function can be fully performed. .

In another embodiment of the invention, the sleeve 12 may be replaced by a sleeve 21 as shown in FIG. This sleeve 21 has a generally cylindrical shape with a circumferentially separated portion, and is made of an elastic material. When this sleeve 21 is attached to the outer periphery of the flexible tube 11, both ends 21a in the circumferential direction,
21b are opened apart from each other and attached to the flexible tube 11. By screwing the cap nut 15, both ends 21a and 21b can be brought into close contact with each other to form a cylindrical shape.

As described above, according to the present invention, the cap nut is screwed forward to press the end of the flexible tube against the joint part, crushing the peak of at least one pitch, and applying pressure to the crushed peak and the outer periphery of the flexible tube. Because of the engagement with the fixed sleeve, the collapsed peaks will not flex and disengage from the sleeve, thus reliably preventing the flexible tube from becoming disconnected. Moreover, the connection work is as simple as screwing in a cap nut, and instead of crushing the end of the flexible pipe in advance with a jig, as in the past, or connecting the flexible pipe and the joint to each other. There is no need for troublesome work such as screwing together the parts, and therefore the connection work is easy. Furthermore, since the sealing member is compressed between the joint portion and the end of the flexible tube by the screwing of the cap nut, sealing performance is improved.

The sleeve has a linear axis and is axially uniformly circular about the axis, so that the sleeve can prevent the flexible tube from radially contracting during tightening. The sealing member is annular and the entire end surface of the flexible tube is pressed uniformly against the end surface where the flexible tube is to be locked, so the sealing member is not damaged or cut and the sealing function is ensured. will be achieved. Further, according to the present invention, the inner thread 2 of the cap nut 15 is attached to the outer thread 19 of the joint portion 13.
0 are screwed together, the end portion 17 of the flexible tube 11 protruding from the sleeve 12 is compressed and crushed in the axial direction, and at this time, the end surface 12d of the sleeves 12 and 21 on the joint portion 13 side is End face 1 of joint part 13
3a, it is possible to keep the interference with which the flexible tube 11 is compressed and crushed to be constant, thereby ensuring sealing performance.

The flexible tube 11 has a bellows shape with peaks and valleys formed in an endless ring shape, and the circumferential ends of the sleeves 12 and 21 are in close contact with each other.
Since the uneven portions 16 fit snugly into the peaks and valleys on the outer circumference of the flexible tube 11, there is no risk of the flexible tube 11 deforming inward in the radial direction, and the sleeve 1
2 and 21 rotate relative to the tube 11, no torsional force is applied to the flexible tube 11 around its axis. The genital tube 11 can now be connected.

Further, according to the present invention, the fitting hole 18 formed in the joint portion 13 includes a sealing member 14 that contacts the bottom 13b and one end surface 12d of the sleeves 12, 21.
The ends 17 of the flexible tube 11 protruding from the sleeves 12, 21 are compressed and crushed between the sleeves 12 and 21. One end surface 12d of the sleeves 12, 21 is in contact with the end surface 13a of the joint portion 13, and the sleeve 12,
Since the other end surface 12c of the flexible tube 21 comes into contact with the pressing surface 15a of the cap nut 15, the problem of the end 17 of the flexible tube 11 being crushed and damaged excessively does not occur. With accurate settings, it is possible to compress and collapse properly. This ensures airtightness.

The end 17 of the flexible tube 11 protruding from the sleeves 12, 21 fits into the fitting hole 18 of the coupling part 13, thus preventing radial outward deformation. Therefore, this end portion 17 can be prevented from being undesirably deformed.

Further, according to the present invention, the flexible tubes 11 are inserted into the insertion holes 15d formed in the cap nut 15 at intervals in the radial direction. Therefore, when the flexible tube 11 is bent by an external force, it is bent with a relatively large radius of curvature and can be prevented from being bent at a steep angle, thereby preventing damage to the flexible tube 11. be able to.

[Brief explanation of the drawing]

1, 2, and 3 are partially cutaway sectional views showing the prior art, FIG. 4 is a sectional view of an embodiment of the present invention, and FIG. 5 is a sleeve 1 shown in FIG. 4.
2 and 6 are perspective views of a sleeve 21 according to another embodiment of the present invention. 11... Flexible tube, 12, 21... Sleeve,
13...Nipple, 14...Seal member, 15...
...Fukuro Natsuto.

Claims (1)

[Claim for Utility Model Registration] In a pipe joint for a bellows-shaped flexible pipe 11 in which peaks and valleys are formed in an endless ring shape, the flexible pipe 11 is divided in the circumferential direction and the ends in the circumferential direction are in close contact with each other. The flexible tube 11 has an uneven portion 16 that fits snugly into the peaks and valleys on the outer circumference of the flexible tube 11 at least one pitch inward from the end of the flexible tube 11 along the axial direction, and the outer shape is in a straight line. sleeves 12 and 21 having a uniform circular shape in the axial direction of the flexible tube; an annular sealing member 14 that abuts the end surface of the end portion 17 of the flexible tube 11 protruding from the sleeve 12 and 21; A fitting hole 18 in which the end portions 17 protruding from the sleeves 12, 21 of 11 are fitted and housed, and a sealing member 14 is fitted into the bottom 13b, and the fitting hole 18 is connected to the bottom 13b via the bottom 13b. and a shaft hole 13c that is smaller in diameter than the fitting hole 18 and that transports fluid, and has an external thread 19 on the outer periphery,
The end surface 13a includes a joint portion 13 that is in contact with one end surface 12d of the sleeves 12 and 21, and a cap nut 15 that has an external thread 1 of the joint portion 13.
9, and the sleeves 12 and 21, which are connected from the inner screw 20 via the step surface 15b and have a smaller diameter than the internal screw 20, are fitted into the sleeve 1.
A fitting hole 15c having the same length as 2 and 21,
An insertion hole 15 that extends from the fitting hole 15c via a stepped pressing surface 15a and has a diameter smaller than that of the fitting hole 15c, through which the flexible tube is inserted at intervals in the radial direction.
d in this order in the axial direction, and the stepped surface 15
b is in contact with the end surface 13a of the joint portion 13, and the pressing surface 15a is in contact with the other end surface 12c of the sleeve 12.
The end portion 17 of the flexible tube 11 protruding from the sleeves 12 and 21 becomes a sealing member by screwing the outer thread 19 and the inner thread 20 together. 14 and sleeve 1
A pipe joint characterized in that it is compressed in the axial direction and collapsed between the first end surface 12d of the pipe fittings 2 and 21.