JP3465418B2 - Plug-in joint and method of assembling this plug-in joint - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a bayonet joint and a method for assembling this bayonet joint.

[0002]

2. Description of the Related Art Conventionally, as a joint for air-tightly or liquid-tightly connecting pipes to each other, a circular or elliptical flange is attached to the end of each pipe by welding or the like, and an annular gasket is arranged between both flanges. Then, there is a type in which a pair of bolts and nuts axially arranged on both flanges are used to bring the two flanges closer to each other, thereby sandwiching and tightening an annular gasket between the two flanges.

[0003]

By the way, in the above-mentioned joint, the flange projects over the entire outer circumference of the pipe, the space occupied by the joint becomes relatively large, and the joint of the pair of bolts and nuts arranged on the axis is symmetrical. Since the annular gasket is tightened by the combination, if the tightening force of one bolt / nut set and the tightening force of the other bolt / nut set are not the same, the annular gasket will not be evenly tightened. In addition to impairing the airtightness or the liquidtightness, the annular gasket may be deteriorated at an early stage. Further, if such a non-uniform force is generated in the joint, a welded portion of the flange to the pipe or the like is likely to crack, which may lead to early destruction of the joint.

The present invention has been made in view of the above points, and an object thereof is to reduce the occupied space, enable uniform tightening, and ensure reliable airtightness or liquid-tightness. It is an object of the present invention to provide a bayonet joint that can obtain the desired properties and can maintain the initial performance for a long period of time, and a method of assembling such a bayonet joint.

[0005]

According to the present invention, the object is to insert the end portion of the inner pipe into the end portion of the outer pipe, and to adjoin the respective end portions of the inner pipe and the outer pipe. An annular gasket is arranged in the annular recess formed between the bead portions formed on the, and the annular gasket is compressed by the tightening means and tightened,
The tightening means compresses the annular gasket in the radial direction so that the inner surface of the bead portion of the inner pipe and the outer surface of the bead portion of the outer pipe come into contact with the inner surface of the bead portion, and the band main body portion disposed around the bead portion. A band that is integrally provided on both edges of the main body and has a flange portion press-contacted to each outer inclined portion of both bead portions so that both bead portions are close to each other in the axial direction. And a reduction means for reducing the diameter of the band.

Further, according to the present invention, the object is to include an inner pipe and an outer pipe each having a bead portion formed adjacent to each one end portion thereof, and a band main body portion, and Prepare a band that can be reduced in diameter and that has flanges that are integrally provided on both edges, and tightening means that includes a means for reducing the diameter of the band, and connect one end of the inner pipe to the outer pipe. Insert the annular gasket around the annular recess that is inserted between the inner pipe and the outer pipe and insert the band main body around the outer side of the annular gasket, and insert the inner pipe and the outer pipe. The inner surface of the band main body is brought into contact with the outer surfaces of both bead portions and the flange portions are pressed against the outer slanted portions of both bead portions. The diameter of the band is reduced by the diameter reducing means so that the beads are axially close to each other, whereby the annular gasket is radially compressed by the band body and the annular gasket is axially compressed by both beads. Then, it is also achieved by a method of assembling a plug-in joint, which comprises press-fitting and expanding an annular gasket in the annular recess and densely arranging the annular gasket in the annular recess.

In a preferred example, both ends of the band body are
The band main body is terminated so that a slit extending obliquely with respect to the axis is formed between both ends of the band main body. By terminating both ends of the band main body in this way, the annular gasket of the joint during assembly is closed. It is possible to prevent a part of the annular gasket from protruding from both ends of the band main body during compression deformation. As the means for reducing the diameter, a flange with a female screw hole attached to one end of the band main body, a flange with a through hole attached to the other end of the band main body, the screw hole of the flange with a screw hole One end is screwed into
It can be presented as a preferable example that the other end is provided with a screw inserted into the through hole of the through hole flange.

When the strength of at least one of the bead portions of the inner pipe and the outer pipe is insufficient, at least one of the bead portions may be formed in a corrugated shape to improve the strength. The annular gasket is preferably composed of a metal mesh formed by knitting or weaving a fine metal wire and expanded graphite filled in the mesh of the metal mesh. From the necessity of compressing the gasket, transmitting bending stress between the inner pipe and the outer pipe, etc., it is preferable that the rigidity is as high as possible. The joint of the present invention is suitable for use in an automobile exhaust pipe and the like.

[0009]

In the insertion joint of the present invention, the connecting portion between the inner pipe and the outer pipe is kept airtight or liquidtight by the annular gasket arranged in the annular recess formed between the bead portions. The bending stress between the inner pipe and the outer pipe is transmitted to each other through the band whose diameter is reduced by the diameter reducing means.

The present invention will now be described in more detail based on the preferred embodiments shown in the drawings. The present invention is not limited to these specific examples.

[0011]

SPECIFIC EXAMPLE In FIGS. 1 to 3, the insertion joint 1 of this example
Inserts the end portion 3 of the inner pipe 2 into the end portion 5 of the outer pipe 4, and between the bead portions 6 and 7 formed on the inner pipe 2 and the outer pipe 4 adjacent to the end portions 3 and 5, respectively. An annular gasket 9 is arranged in the resulting annular recess 8 and the annular gasket 9 is compressed and tightened by the tightening means 10.

The inner pipe 2 comprises a main body portion 21, a bead portion 6 integrally formed with the main body portion 21, and an end portion 3 integrally formed with the bead portion 6, and the bead portion 6 is
The flat annular portion 22 has an outer diameter larger than that of the main body portion 21, and inner and outer inclined portions 23 and 24 integrally formed at both ends of the flat annular portion 22, and the end portion 3 has an inner inclined portion. It is formed continuously with the portion 23.

The outer pipe 4 has a main body portion 31, a bead portion 7 integrally formed with the main body portion 31, and an end portion 5 integrally formed with the bead portion 7, and the bead portion 7 is
The flat annular portion 32 has an outer diameter larger than that of the main body portion 31, and inner and outer inclined portions 33 and 34 integrally formed at both ends of the flat annular portion 32. The end portion 5 has an inner inclined portion. It is formed continuously with the portion 33, and its inner diameter is the end portion 3.
The outer diameter is larger than the outer diameter, and the end 3 is inserted into the end 5.

The tightening means 10 compresses the annular gasket 9 in the radial direction so that the inner pipe 2 and the outer pipe 4 are compressed.
A flat band body portion 44 arranged around the bead portions 6 and 7 so that the inner surfaces 43 contact the outer surfaces 41 and 42 of the flat annular portions 22 and 32 of the bead portions 6 and 7, respectively.
And the outer inclined portions 24 and 3 of the bead portions 6 and 7 are integrally provided on both edges of the band body portion 44 so that the bead portions 6 and 7 are axially close to each other.
It is provided with a diameter-reducible band 47 having flange portions 45 and 46 that are pressed against 4 and a diameter reduction means 48 for reducing the diameter of the band 47. Both ends 51 and 52 of the band main body 44 are terminated so that a slit 53 extending obliquely with respect to the axis is formed between the both ends 51 and 52 of the band main body 44.

The diameter reducing means 48 is a female screw 55 attached to one end 54 of the band body 44 by welding or the like.
A flange 56 with a hole, a flange 59 with a through hole 58 attached to the other end 57 of the band main body 44 by welding or the like, one end of which is screwed into a screw hole 55 of the flange 56, and the other end is a flange 59. And a screw 61 with an enormous head portion 60 inserted through the through hole 58 of FIG. Flange 5
6 has a pair of reinforcing portions 62.

The annular gasket 9 comprises a metal mesh formed by knitting fine metal wires and expanded graphite filled in the mesh of the metal mesh. The annular gasket 9 composed of such a metal mesh and expanded graphite has a diameter It is compressed in the axial and axial directions and is densely arranged in the annular recess 8.

The insertion joint 1 formed as described above is
The inner pipe 2 and the outer pipe 4 are connected to each other, and the annular recess 8 between the inner inclined portions 23 and 33 of the bead portions 6 and 7 is formed.
The connecting portion between the inner pipe 2 and the outer pipe 4 is kept airtight or liquid-tight by the annular gasket 9 arranged in the. The bending stress between the inner pipe 2 and the outer pipe 4 is transmitted to each other via the band 47 whose diameter is reduced by the diameter reducing means 47.

Therefore, the plug-in joint 1 does not require a flange arranged around the ends 3 and 5 of the inner pipe 2 and the outer pipe 4, so that the occupied space can be reduced and the diameter can be reduced. Since the band 47 whose diameter is reduced by the means 48 is used for tightening, uniform tightening is possible, reliable airtightness or liquid tightness can be obtained, and initial performance can be maintained for a long period of time.

Next, a method of assembling the above-mentioned plug-in joint 1 will be described. An inner pipe 2 and an outer pipe 4 each having a bead portion 6 and 7 formed adjacent to one end portions 3 and 5, respectively, and a band. Body 44
The tightening means 10 including a diameter-reducing band 47 that is integrally provided on both edges of the band body 44 and that includes flange portions 45 and 46, and a diameter-reducing means 48 that reduces the diameter of the band 47. And prepare.

Next, as shown in FIG. 4, one end 3 of the inner pipe 2 is inserted into one end 5 of the outer pipe 4,
An annular gasket 9 as shown in FIGS. 5 and 6 is arranged around the annular recess 8 formed between the inner inclined portions 23 and 33 of the bead portions 6 and 7 of the inner pipe 2 and the outer pipe 4, respectively. The annular gasket 9 is formed by stacking a metal mesh formed by knitting thin metal wires and a sheet-shaped expanded graphite, and winding the stacked one into a cylindrical shape.
It is preferable to use a material obtained by pre-compressing the wound material with a molding die and comprising a metal mesh and expanded graphite filled in the mesh of the metal mesh.

Next, as shown in FIG. 4, a band main body portion 44 is arranged around the annular gasket 9, and further flat annular portions 22 of both the bead portions 6 and 7 of the inner pipe 2 and the outer pipe 4 are formed. The outer surfaces 41 and 42 of 32 are brought into contact with the inner surface 43 of the band body 44, and the flange portions 45 and 4 corresponding to the outer inclined portions 24 and 34 of both bead portions 6 and 7, respectively.
6 is pressed to rotate the screw 61 of the diameter reducing means 48 so that the bead portions 6 and 7 are brought closer to each other in the axial direction, and the flange 56 and the flange 59 are brought closer to reduce the diameter of the band 47. While further compressing the precompression-molded annular gasket 9 in the radial direction by the band body portion 44,
Similarly, the annular gasket 9 is further compressed in the axial direction by the inner inclined portions 23 and 33 of both the bead portions 6 and 7, and the annular gasket 9 is press-fitted into the annular recess 8 and spread, so that The annular gaskets 9 are densely arranged to obtain the plug-in joint 1.

By the way, in the plug-in joint 1, FIG. 5 and FIG.
Although the annular gasket 9 having the flat outer peripheral surface 71 as shown in FIG. 7 is used, instead of this, the outer peripheral surface 7 as shown in FIG.
A plug-in joint may be formed in the same manner as the plug-in joint 1 by using the pre-compression-molded ring-shaped gasket 73 having the ring-shaped ridges 72 in 1.

Further, as shown in FIG. 8, the bead portions 6 and 7 of the inner pipe 2 and the outer pipe 4, respectively.
May be formed in a corrugated shape to form the insertion joint 81. In the plug-in joint 81, the insufficient strength of the bead portions 6 and 7 can be compensated, and therefore it may be preferable.

[0024]

As described above, according to the present invention, the occupied space can be reduced, uniform tightening can be performed, and
It is possible to obtain reliable air tightness or liquid tightness and maintain the initial performance for a long time.

[Brief description of drawings]

1 shows a preferred embodiment of the present invention II shown in FIG.
It is a line sectional view.

FIG. 2 is a plan view of the specific example shown in FIG.

FIG. 3 is a side view of the fastening means of the one specific example shown in FIG.

4 is an explanatory view of an assembling method of the one specific example shown in FIG. 1. FIG.

5 is a partial cross-sectional view of a pre-compression-molded annular gasket used in the specific example shown in FIG.

6 is a side view of the annular gasket shown in FIG.

FIG. 7 is a partial cross-sectional view of another example of a precompression molded annular gasket that can be used in the bayonet joint of the present invention.

FIG. 8 is a cross-sectional view of another preferred embodiment of the present invention.

[Explanation of symbols]

1 plug joint 2 Inner pipe 3, 5 edge 4 Outer pipe 6, 7 bead part 8 annular recess 9 Annular gasket 10 Tightening means 24, 34 Outer slope 44 band body 45, 46 Flange 47 bands 48 Diameter reduction means

Claims (5)

(57) [Claims] 1. An end portion of an inner pipe is inserted into an end portion of an outer pipe, and an annular recess formed between bead portions formed in the inner pipe and the outer pipe is adjacent to the respective end portions. arranged annular gasket becomes tightened and compressed by clamping means of this annular gasket, which between the inner pipe and the outer pipe
At least one of the beads is corrugated.
The tightening means compresses the annular gasket in the radial direction, so that the inner surfaces of the inner pipe and the outer pipe contact the outer surfaces of both bead portions, and the band main body portion disposed around both bead portions, It is integrally provided on both edges of the band main body, and has a flange portion press-contacted to each outer inclined portion of both bead portions so that both bead portions are close to each other in the axial direction. Plug-in joint provided with a small band and a diameter reducing means for reducing the diameter of the band. 2. The bayonet joint according to claim 1, wherein both ends of the band body are terminated so that slits extending obliquely with respect to the axis are formed between both ends of the band body. 3. The diameter reducing means is a flange with a female screw hole attached to one end of the band body, a flange with a through hole attached to the other end of the band body, and a flange with a screw hole. One end is screwed into the screw hole of
The insertion joint according to claim 1 or 2, wherein the other end is provided with a screw inserted into the through hole of the flange with a through hole . 4. The annular gasket comprises a metal mesh formed by knitting or weaving fine metal wires and expanded graphite filled in the mesh of the metal mesh.
The insertion joint according to any one of 1 to 3 . 5. A bead portion formed adjacent to each one end portion, at least one of which is formed in a corrugated shape.
And an outer pipe each having a bead portion , and a band that can be reduced in diameter and that includes a band body portion and flange portions that are integrally provided on both edges of the band body portion. And a tightening means having a diameter reducing means for reducing the diameter of the inner pipe are inserted, and one end of the inner pipe is inserted into one end of the outer pipe.
Arrange an annular gasket around the annular recess that occurs between the bead portions of the inner pipe and the outer pipe,
Place the band body around the outside of this annular gasket,
The inner surface of the band main body is brought into contact with the outer surfaces of the bead portions of the inner pipe and the outer pipe, and the flange portions are pressed against the outer inclined portions of both bead portions so that the bead portions are axially close to each other. , The diameter of the band is reduced by the diameter reducing means, whereby the band gasket compresses the annular gasket in the radial direction, and the bead portions compress the annular gasket in the axial direction to press the annular gasket into the annular recess. , A method of assembling a bayonet joint, which comprises spreading and densely placing an annular gasket in the annular recess.