JPH0979454A - Exhaust pipe joint and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the exhaust pipe joint and its manufacture, which can make any adjustment unnecessary, can make the degree of compressive deformation of a cylindrical gasket roughly identical in the circumferential direction, can preferably prevent exhaust gas from leaking, concurrently can prevent the cylindrical gasket from being damaged because of vibration of both its inner and outer pipes, and furthermore can make its operating performance excellent for manufacture and assembly/disassembly. SOLUTION: The exhaust joint 1 is equipped with an outer pipe 5, an inner pipe 9, a cylindrical gasket 13, and with a pressing/fixing means 14, and the pressing/fixing means 14 is equipped with a cut split 31 which is formed over the diameter enlarging end part 4 of the outer pipe 5 while being extended along its pipe axis A, a locking part 32 provided for the diameter enlarging end part 4, a locking part 33 provided for the diameter enlarging part 8 of the inner pipe 9, and with a fastening band 35 fastening the diameter enlarging end part 4 on-to a diameter enlarging part 6. The fastening band 35 is equipped with a band main body 41, and with a slice part 44 provided integrally with the band main body 41, and the cylindrical gasket 13 is pressed against the outer pipe 5 by the slice part 44 through a shoulder part 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust pipe joint used for automobiles, motorcycles and the like.

[0002]

As an exhaust pipe joint of this kind, the present applicant has filed Japanese Utility Model Application No. 3-88552.
32718), a cylindrical gasket disposed in the space between the enlarged cylindrical portion of the outer pipe and the outer surface of the inner pipe is pressed along the pipe axis by a pair of pressing pieces to be compressed and deformed, and the space is closed by the cylindrical gasket. Closely fill the gaps existing at the time of assembly to prevent leakage of exhaust gas immediately after fitting the joint to the exhaust pipe, and tighten the pair of pressing pieces described above to connect with the outer pipe. We proposed an exhaust pipe joint that fixes the inner pipe to each other and prevents damage to the cylindrical gasket due to vibration of the outer pipe and the inner pipe.

By the way, in the exhaust pipe joint according to the above proposal,
It was confirmed that the initial purpose of preventing the leakage of exhaust gas immediately after the fitting to the exhaust pipe and preventing the damage of the cylindrical gasket can be preferably achieved. Since the pressing piece is moved by tightening the bolts, the cylindrical gasket is compressed and deformed into the space between the enlarged cylindrical portion of the outer tube and the outer surface of the inner tube. It was found that if the difference is different, the degree of compressive deformation of the cylindrical gasket differs in the circumferential direction, and as a result, prevention of leakage of exhaust gas may not be achieved favorably. Therefore, when manufacturing, disassembling and assembling the exhaust pipe joint, it is necessary to mutually adjust the degree of tightening of the pair of bolts, and the workability is not so excellent. In the specific example of the exhaust pipe joint proposed above, mutual fixing of the outer pipe and the inner pipe by tightening the pair of pressing pieces is performed by tightening a pair of bolts further provided outside the pair of bolts. Therefore, when manufacturing and disassembling and assembling the same, it is necessary to tighten two pairs of bolts, which is not so excellent in workability.

The present invention has been made in view of the above points, and an object thereof is that adjustment is unnecessary and the degree of compressive deformation of a cylindrical gasket can be made substantially the same in the circumferential direction, Exhaust gas leakage prevention can be preferably achieved, damage to the cylindrical gasket due to vibration of the outer pipe and the inner pipe can be prevented, and in addition, an exhaust pipe joint having excellent manufacturing and disassembly and assembly workability and its manufacture To provide a method.

[0005]

[Means for Solving the Problems] To achieve the above object,
According to the present invention, the outer tube body and the outer tube having the enlarged diameter end portion connected to the outer tube body via the shoulder portion, the end portion inserted into the enlarged diameter end portion of the outer tube, and this end Inner tube having a diametrically expanded portion connected to the diametrical portion via a shoulder and inserted into the diametrically expanded end of the outer tube, an outer peripheral surface of the inner pipe end and an inner peripheral surface of the diametrically expanded end of the outer pipe. A cylindrical gasket disposed in an annular space between the surface and the surface, and pressing and fixing means for pressing the cylindrical gasket toward the shoulder portion of the outer tube along the tube axis and fixing the outer tube to the inner tube. In the exhaust pipe joint, the pressing and fixing means are provided on at least a pair of slit grooves formed along the pipe axis at the enlarged diameter end portion of the outer pipe, and at the enlarged diameter end portion of the outer pipe. And the locking part on the outer tube side,
The inner pipe-side locking portion that extends through the slits to the outside of the outer pipe and is provided on the expanded diameter portion of the inner pipe, and one end abuts the outer-pipe-side locking portion, A tightening band for tightening the expanded diameter end portion to the expanded diameter portion of the inner pipe is provided, and the tightening band is provided integrally with the band body having one end that abuts the locking portion on the outer pipe side and the band body. And a tongue portion in which each tip located on the other end side of the band body is in contact with a locking portion on the inner pipe side, and the cylindrical gasket is configured by the tongue portion via the shoulder portion of the inner pipe. An exhaust pipe fitting is provided that is urged toward the shoulder of the.

Further, according to the present invention, the locking portion on the inner pipe side is
A block body welded and fixed to the expanded portion of the inner pipe, an L-shaped member having a cross-section welded and fixed to the expanded portion of the inner pipe, or a projection formed by forming the expanded portion of the inner pipe into a bead shape. An exhaust fitting is provided.

Further in accordance with the present invention, the pair of slit grooves are
There is provided the above exhaust pipe joint which is formed symmetrically with respect to the pipe axis.

Further, according to the present invention, the above object is to provide an outer tube main body, an enlarged diameter end portion connected to the outer tube main body through a shoulder portion,
An outer tube having at least a pair of slit grooves formed along the tube axis at the expanded diameter end and an engaging portion provided at the expanded diameter end, and an end into which a cylindrical gasket is inserted. Section, an enlarged diameter portion connected to this end portion via a shoulder portion, and an inner tube having a locking portion provided corresponding to the pair of slit grooves on the enlarged diameter portion, a band body, and A tightening band provided with a tongue part which is provided corresponding to the locking part of the inner pipe and which is bent toward the center side and integrally provided on the band body is prepared, and an inner pipe having a cylindrical gasket inserted therein. The end portion of the inner pipe and the expanded portion of the inner pipe, the locking portion on the inner pipe side extends outside the outer pipe through each of the slit grooves, and the cylindrical gasket forms the outer peripheral surface of the end portion of the inner pipe and the outer pipe. Inserted into the expanded end of the outer pipe so that it is arranged in the annular space between the inner peripheral surface of the expanded end and the locking part on the outer pipe side. Place the tightening band on the outer peripheral surface of the expanded end of the outer tube so that each tongue is located between the inner tube and each locking part, and tighten it. The bent tongue is released from the bend to extend the tongue in the tube axis direction, and one end of the band main body is pressed so that the cylindrical gasket is pressed toward the shoulder of the outer tube through the shoulder of the inner tube. While making pressure contact with the locking portion on the outer tube side, press the tips of the tongues located on the other end side of the band body to each locking portion on the inner tube side, and by tightening the expanded tube end portion of the outer tube. It is also achieved by a method of manufacturing an exhaust pipe joint that presses and fixes the expanded portion of the inner pipe.

Examples of the material for the tightening band include steel, stainless steel, spring materials and the like. Normally, the outer pipe that constitutes the exhaust pipe of the exhaust pipe joint is fixed to the muffler side, and the inner pipe that constitutes the exhaust pipe connected to the outer pipe is fixed to the engine side, but not limited to this. . The cylindrical gasket is not particularly limited as long as it is a material that is easily deformed when compressed and has heat resistance, and is made of, for example, a wire net obtained by weaving or knitting metal thin wires such as stainless steel. Reinforcement material, heat-resistant sheet such as expanded graphite, mica, etc. are superposed, and this is wound into a cylindrical shape to form a preformed body, and then the preformed body is compressed in the axial direction. It can be mentioned as a suitable example.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in more detail based on the preferred embodiments shown in the drawings. The present invention is not limited to these examples.

[0011]

1 to 4, an exhaust pipe joint 1 of this example is shown.
Is inserted into the outer tube body 2 and the outer tube body 5 and the outer tube body 5 having the radially expanded end portion 4 integrally connected to the outer tube body 2 via the shoulder portion 3. An inner pipe 9 having an end portion 6 and an enlarged diameter portion 8 integrally connected to the end portion 6 via a shoulder portion 7 and inserted into the enlarged diameter end portion 4 of the outer pipe 5, and an end of the inner pipe 9. The cylindrical gasket 13 arranged in the annular space 12 between the outer peripheral surface 10 of the portion 6 and the inner peripheral surface 11 of the expanded diameter end 4 of the outer tube 5, and the cylindrical gasket 13 along the tube axis A. Pressing and fixing means 14 for pressing the outer tube 5 to the inner tube 9 while pressing it toward the shoulder portion 3 of the
Is provided.

The outer tube body 2 of this example comprises a small diameter portion 21 and a large diameter portion 22, and the small diameter portion 21 and the large diameter portion 22 are
They are connected to each other via another shoulder 23. Large diameter part 2
2 is integrally connected to the enlarged diameter end portion 4 via the shoulder portion 3. The inner pipe 9 includes a small-diameter inner pipe body 25, the end portion 6 and the enlarged diameter portion 8 described above, and the inner pipe body 25 and the end portion 6 are formed to have the same diameter. The inner tube body 25 does not have to have the same diameter as the end portion 6 as in this example, and may be formed to have the same diameter as the expanded diameter portion 8, for example. Inner tube body 25
And the enlarged diameter portion 8 are connected via a shoulder portion 26.

A pair of pressing and fixing means 14 is formed on the enlarged diameter end portion 4 of the outer tube 5 so as to extend along the pipe axis A from the tip of the enlarged diameter end portion 4 and to be symmetrical with respect to the pipe axis A. Slit groove 31
An outer pipe side engaging portion 32 formed of a flange portion integrally formed at the tip of the enlarged diameter end portion 4 of the outer pipe 5, and a slit groove 31.
A pair of locking portions 33 on the inner pipe side that extend outside the enlarged diameter end portion 4 of the outer pipe 5 and are fixed to the enlarged diameter portion 8 of the inner pipe 9 by welding. A tightening band 35 for tightening the expanded diameter end portion 4 of the outer pipe 5 to the expanded diameter portion 8 of the inner pipe 9 by contacting the one end 34 with the locking portion 32 on the outer pipe side, and a bolt 36 and a nut for tightening the tightening band 35. And a tightening means 38 composed of a combination of 37.

The tightening band 35 is a locking portion 32 on the outer tube side.
A band body 41 having one end 34 abutting on the band body 41, and the tips 43 which are integrally provided symmetrically with respect to the tube axis A on the band body 41 and located on the other end 42 side of the band body 41.
A pair of tongue portions 44 that are in contact with the respective locking portions 33 on the inner pipe side,
The band main body 41 is provided with mounting portions 45 and 46 of the tightening means 38 which are integrally provided at both ends in the circumferential direction so as to extend substantially radially and outwardly. Each tongue portion 44 is a band body 4
1 is formed with a notch 47. Through holes 47 and 48 through which the bolt 36 penetrates are formed in the mounting portions 45 and 46, and are reinforced by reinforcing ribs 49 and 50. The diameter-expanded end portion 4 of the outer pipe 5 is fixed to the outer peripheral surface of the diameter-expanded portion 8 of the inner pipe 9 by reducing the diameter of the band main body 41 by screwing the nut 37 onto the bolt 36.

A reinforcing material made of wire mesh obtained by weaving or knitting metal fine wires made of stainless steel and a heat resistant sheet made of expanded graphite are superposed and wound in a cylindrical shape to form a preform. After that, the cylindrical gasket 13 produced by axially compressing this preform has
Is pressed against the shoulder portion 3 of the outer tube 5 via the shoulder portion 7 of the inner tube 9 and arranged.

The two slit grooves 31 in this example are formed symmetrically with respect to the tube axis A, but three or more slit grooves 31 may be provided. For example, when three slit grooves 31 are provided, Although not particularly limited, it may be provided at equal angular intervals of 120 degrees with respect to the circumferential direction, and in this case, it is preferable to provide the locking portions 33 correspondingly. The locking portion 32 on the outer tube 5 side may be implemented by a flange portion formed by expanding the tip of the expanded diameter end 4 as in this example, but instead of this, for example, a expanded diameter end It may be implemented by a collar member or an inverted L-shaped metal member integrally formed or fixed to the tip of the portion 4 by welding or the like.

Next, the method of manufacturing the exhaust pipe joint 1 will be described with reference to FIG. 5 as well. First, the outer pipe body 2 and the enlarged diameter end portion 4 connected to the outer pipe body 2 via the shoulder portion 3, The pair of slits 31 extending along the tube axis A is formed in the expanded diameter end portion 4 and the locking portion 32 provided at the tip of the expanded diameter end portion 4 described above. The pipe 5, the end portion 6 in which the cylindrical gasket 13 is attached to the outside, the enlarged diameter portion 8 connected to the end portion 6 via the shoulder portion 7 and the enlarged diameter portion 8 correspond to the pair of slit grooves 31. 3 each provided with a locking portion 33 provided by
And the tongue portion 44 provided corresponding to the band body 41 and the locking portion 33 of the inner tube 9 and bent toward the center and integrally provided on the band body 41. The above-mentioned tightening band 35 shown in FIG. 4 is prepared.

Next, the end portion 6 of the inner pipe 9 having the cylindrical gasket 13 inserted therein and the enlarged diameter portion 8 of the inner pipe 9, and the engagement portion 33 on the inner pipe side of the slit groove 31, respectively. Through the outer pipe 5 and the cylindrical gasket 13 is arranged in the annular space 12 between the outer peripheral surface 10 of the end portion 6 and the inner peripheral surface 11 of the expanded diameter end portion 4, So that the tongues 44 are arranged between the outer tube-side locking portions 32 and the inner tube-side locking portions 33 as shown in FIG. And disposing the tightening band 35 on the outer peripheral surface of the expanded diameter end 4 of the outer tube 5,
Tightening band 3 by screwing nut 37 onto bolt 36
5, the band body 41 is reduced in diameter by this tightening, and the bending of the tongue portions 44 bent toward the center side is released to extend the tongue portions 44 in the direction of the tube axis A. One end 34 of the band body 41 is pressed against the outer tube side locking portion 32 so as to be pressed toward the shoulder 3 of the outer tube 5 via the shoulder 7 of the tube 9, and the other end of the band body 41 is pressed. 42
Each tip 43 of the tongue portion 44 located on the side is pressed against each locking portion 33 on the inner pipe side, and the enlarged diameter end portion 4 of the outer pipe 5 is fixed to the enlarged diameter portion 8 of the inner pipe 9 by tightening the band 35. Fixed to. Thereby, the exhaust pipe joint 1 can be obtained.

In the exhaust pipe joint 1, the cylindrical gasket 1
Since the outer peripheral surface 10 and the inner peripheral surface 11 are pressed into close contact with each other 3 and are closely packed in the annular space 12, the exhaust gas can be prevented from leaking from the annular space 12 as desired.

Further, in the exhaust pipe joint 1, by tightening the bolt 36, the bending of each tongue portion 44 is released and each tongue portion 4 is released.
4 is extended in the direction of the tube axis A, whereby the locking portion 32 and the locking portion 33 are separated from each other along the tube axis A, and the cylindrical gasket 13 is pressed and compressed and deformed via the shoulder portion 7. Therefore, the degree of compressive deformation of the cylindrical gasket 13 can be made substantially the same in the circumferential direction without adjusting the degree of tightening of the bolt 36. In other words, in the exhaust pipe joint 1 of this example, the cylindrical gasket 13 is subjected to compressive deformation of a predetermined amount or more.
However, in order to make the degree of compressive deformation of the cylindrical gasket 13 approximately the same in the circumferential direction, the tightening adjustment of the bolt 36 may be unnecessary. .

In the exhaust pipe joint 1, since the expanded end 4 is pressed and fixed to the outer peripheral surface of the expanded part 8 and the outer pipe 5 is fixed to the inner pipe 9, the outer pipe 5 and the inner pipe 9 are fixed. It is possible to eliminate the relative microvibration relative to 9 and to prevent deterioration of the cylindrical gasket 13 due to the microvibration of the shoulder portion 7.

In the above description, the inner pipe side locking portion 33 is a block body welded and fixed to the expanded diameter portion 8 of the inner pipe 9. However, instead of this, as shown in FIG. Even if the locking portion 33 is implemented by a member composed of an L-shaped section member welded and fixed to the expanded diameter portion 8 of the pipe 9, as shown in FIG.
The engaging portion 33 is a protrusion formed by molding the enlarged diameter portion 8 of the
May be implemented.

[0023]

As described above, according to the present invention, no adjustment is required, the degree of compressive deformation of the cylindrical gasket can be made substantially the same in the circumferential direction, and the prevention of leakage of exhaust gas can be preferably achieved. It is possible to prevent the damage of the cylindrical gasket due to the vibration of the outer pipe and the inner pipe, and to provide the exhaust pipe joint which is extremely excellent in the workability of manufacturing and disassembling and assembling.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a preferred embodiment of the present invention.

2 shows an outer tube used in the embodiment shown in FIG.
(A) is the front view, (b) is the left side view.

FIG. 3 shows an inner tube used in the embodiment shown in FIG.
(A) is the front view, (b) is the left side view.

4 shows a tightening band and the like used in the embodiment shown in FIG. 1, (a) is a side view thereof, (b) is a front view thereof, and (c) is (b). 6 is a sectional view taken along line cc shown in FIG.

FIG. 5 is an explanatory view of the manufacturing method of the embodiment shown in FIG.

FIG. 6 is an explanatory view of another preferred embodiment of the present invention.

FIG. 7 is an explanatory diagram of still another preferred embodiment of the present invention.

[Explanation of symbols]

 1 Exhaust Pipe Joint 2 Outer Pipe Body 3, 7 Shoulder 4 Expanded End 5 Outer Pipe 6 End 8 Expanded 9 Inner Tube 12 Annular Space 13 Cylindrical Gasket 14 Pressing, Fixing Means 31 Cut Grooves 32, 33 Locking part 35 Tightening band 41 Band body 44 Tongue

Claims (6)

[Claims] 1. An outer tube having an outer tube main body and an expanded diameter end connected to the outer tube main body via a shoulder, an end inserted into the expanded diameter end of the outer tube, and this end. An inner pipe having a diameter-expanded portion that is connected to the outer diameter of the outer pipe and is inserted into the diameter-expansion end of the outer pipe, and an outer peripheral surface of an end portion of the inner pipe and an inner peripheral surface of the diameter-enlarged end portion of the outer pipe. And a cylindrical gasket disposed in an annular space between and, and a pressing and fixing means for pressing the cylindrical gasket along the tube axis toward the shoulder of the outer tube and fixing the outer tube to the inner tube. In the exhaust pipe joint, the pressing and fixing means are provided in at least a pair of slit grooves formed along the pipe axis at the enlarged diameter end portion of the outer pipe, and at the enlarged diameter end portion of the outer pipe. The outer tube side locking part, the inner tube side locking part that extends outside the outer tube through each of the slit grooves and is provided in the expanded diameter part of the inner tube, and the one end is the outer tube side locking Abut the outer tube And a tightening band for tightening the expanded end portion of the inner pipe to the expanded portion of the inner pipe, and the tightening band is integrally formed with the band main body having one end in contact with the locking portion on the outer pipe side and the band main body. The distal end of the band main body located on the other end side of the band body is provided with a tongue that abuts on the locking portion on the inner pipe side. Exhaust pipe fitting that is pressed against the shoulder of the pipe and arranged. 2. The exhaust pipe joint according to claim 1, wherein the engagement portion on the inner pipe side is a block body welded and fixed to the expanded diameter portion of the inner pipe. 3. The exhaust pipe joint according to claim 1, wherein the engagement portion on the inner pipe side is made of a member having an L-shaped cross section which is welded and fixed to the expanded diameter portion of the inner pipe. 4. The exhaust pipe joint according to claim 1, wherein the engagement portion on the inner pipe side is a protrusion formed by molding the enlarged diameter portion of the inner pipe into a bead shape. 5. The exhaust pipe joint according to claim 1, wherein the pair of slit grooves are formed symmetrically with respect to the pipe axis. 6. An outer tube body, an enlarged diameter end portion connected to the outer tube body via a shoulder portion, at least a pair of slit grooves formed along the tube axis at the enlarged diameter end portion, and The outer tube each having a locking portion provided at the enlarged diameter end, the end portion where the cylindrical gasket is inserted, the enlarged diameter portion connected to this end portion via the shoulder portion, and the enlarged diameter portion , An inner tube having locking parts provided corresponding to the pair of slits, respectively, and a band main body and an inner tube provided corresponding to the locking parts of the inner tube and bent toward the center to be integrated with the band main body Clamps each having a tongue portion that is provided in a special manner are prepared, and the end portion of the inner pipe in which the cylindrical gasket is inserted and the expanded portion of the inner pipe are cut by the engagement portion on the inner pipe side. A cylindrical gasket extends through each of the grooves to the outside of the outer pipe, and a cylindrical gasket is provided between the outer peripheral surface of the end of the inner pipe and the inner peripheral surface of the expanded end of the outer pipe. Inserted into the expanded diameter end of the outer pipe so that it is arranged in the annular space, so that each tongue is arranged between the outer pipe-side locking portion and each inner pipe-side locking portion. , A tightening band is arranged on the outer peripheral surface of the expanded diameter end of the outer tube and tightened to release the bending of the tongue that is bent toward the center side by this tightening and extend the tongue in the tube axis direction. The tongue located on the other end of the band body is pressed against one end of the band body so that the gasket is pressed toward the shoulder of the outer tube through the shoulder of the inner tube. A method for manufacturing an exhaust pipe joint, wherein each tip of a portion is pressed against each locking portion on the inner pipe side, and the enlarged diameter end portion of the outer pipe is fixed to the enlarged diameter portion of the inner pipe by the tightening.