JP3158858B2 - Exhaust pipe joint and method of manufacturing the same - Google Patents

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]

2. Description of the Related Art As an exhaust pipe joint of this type, the present applicant has
In Japanese Utility Model Application Laid-Open No. 3-88552 (Japanese Utility Model Application Laid-Open No. 5-32718), a cylindrical gasket disposed in the space between the enlarged cylindrical portion of the outer tube and the outer surface of the inner tube is pressed along the tube axis by a pair of pressing pieces. And compressively deform, filling the space with a cylindrical gasket more densely, filling the gap existing at the time of assembly,
As a result, the exhaust gas is prevented from leaking immediately after the fitting to the exhaust pipe, and the outer pipe and the inner pipe are fixed to each other by tightening the pair of pressing pieces, and the outer pipe and the inner pipe are connected to each other. An exhaust pipe joint was proposed to prevent damage to the cylindrical gasket caused by vibration of the exhaust pipe.

[0003]

In the exhaust pipe joint according to the above proposal, the initial purpose of preventing leakage of exhaust gas immediately after the fitting to the exhaust pipe and preventing damage to the cylindrical gasket is preferable. Although it was confirmed that this could be achieved, in the specific example specified therein, the cylindrical gasket was compressed into the space between the enlarged cylindrical portion of the outer tube and the outer surface of the inner tube by moving the pressing piece by tightening a pair of bolts. Therefore, when the degree of tightening of the pair of bolts is different from each other, the degree of compressive deformation of the cylindrical gasket is different in the circumferential direction, and as a result, it is not possible to preferably achieve prevention of leakage of exhaust gas. It turned out that there was a fear. For this reason, when manufacturing and disassembling and assembling the exhaust pipe joint, mutual adjustment of the degree of tightening of the pair of bolts is required, and the workability is not so excellent. Further, in the specific example of the exhaust pipe joint proposed above, the mutual fixing between 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 above-described pair of bolts. Therefore, in the manufacture, disassembly and assembly thereof, it is necessary to tighten two pairs of bolts, and in this respect, the workability is not so excellent.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and has as its object the need for adjustment, the degree of compressive deformation of a cylindrical gasket can be made substantially the same in the circumferential direction, and Exhaust pipe joint which can preferably achieve gas leakage prevention, can prevent damage to a cylindrical gasket due to vibration of an outer pipe and an inner pipe, and is extremely excellent in manufacturing, disassembling and assembling workability, and a method of manufacturing the same. Is to provide.

[0005]

SUMMARY OF THE INVENTION According to the present invention, there is provided an outer tube having an outer tube body, an outer tube having an enlarged end connected to the outer tube body via a shoulder, and an outer tube having an enlarged diameter. An inner tube having an end inserted into the radial end and an enlarged portion connected to the end via a shoulder and inserted into the enlarged end of the outer tube, and an outer periphery of the end of the inner tube A cylindrical gasket disposed in an annular space between the surface and the inner peripheral surface of the enlarged end of the outer tube, and pressing the cylindrical gasket along the tube axis and toward the shoulder of the outer tube; An exhaust pipe joint comprising a pressing and fixing means for fixing to an inner pipe, wherein the pressing and fixing means comprises at least one pair of split grooves formed along a pipe axis at an enlarged-diameter end of an outer pipe. And an outer tube-side engaging portion provided at the enlarged end portion of the outer tube, and an inner tube side provided at the enlarged portion of the inner tube, extending outside of the outer tube through each of the slit grooves. Person in charge A pressure member disposed on the outer peripheral surface of the enlarged diameter end portion of the outer tube with one end abutting on the locking portion on the outer tube side and the other end abutting on the locking portion on the inner tube side; A clamping band for clamping and holding the member to the enlarged end of the outer tube, wherein the cylindrical gasket is pressed by the pressing member through the shoulder of the inner tube toward the shoulder of the outer tube; Is elastically deformed by tightening the tightening band so that the length in the direction along the pipe axis is elongated, and the enlarged diameter end of the outer pipe is
This is achieved by the exhaust pipe joint pressed and fixed to the enlarged diameter portion of the inner pipe by tightening the tightening band.

According to the present invention, the object is to provide an outer tube main body, an enlarged end portion connected to the outer tube main body via a shoulder,
An outer tube having at least a pair of slits formed at the enlarged diameter end along the pipe axis and an engaging portion provided at the enlarged diameter end, and an end having a cylindrical gasket inserted therein. Part, an enlarged portion connected to the end portion via a shoulder portion, and an inner tube provided with an engaging portion provided on the enlarged portion, respectively, and an inner tube having a cylindrical gasket inserted therein is prepared. The end portion and the enlarged diameter portion of the inner pipe are connected to each other. It is arranged in the annular space between the inner peripheral surface of the radial end and inserted into the enlarged end of the outer tube, and is inserted between the outer tube side engaging portion and the inner tube side engaging portion. In the above, a pressing member elastically deformable in the tube axis direction is disposed on the outer peripheral surface of the enlarged end portion of the outer tube, and a tightening band disposed on the outer peripheral surface of the pressing member is tightened. One end of the pressing member is engaged with the outer tube so that the pressing member is elastically deformed and extended in the tube axis direction, and the cylindrical gasket is pressed toward the shoulder of the outer tube via the shoulder of the inner tube. The outer end of the outer tube is pressed and fixed to the enlarged portion of the inner tube via the pressing member by the tightening while the other end is brought into contact with the stop portion and the other end is brought into contact with the locking portion on the inner tube side. This is achieved by a method of manufacturing an exhaust pipe joint.

[0007] In the exhaust pipe joint, an arc-shaped cross section or a cross-sectional waveform can be given as a preferred example of the shape of the pressing member before tightening, but the present invention is not limited to this. Further, if the pressing member is fixed to the band body of the tightening band by spot welding or the like, disassembly and assembly at the time of manufacture and maintenance are further facilitated. As the pressing member, a member made of one member in which a band main body having an arc-shaped cross section or a corrugated cross section is wound around the enlarged-diameter end portion can be presented as an example. It may consist of a pair of divided pieces arranged. Examples of the material of the pressing member include steel, stainless steel, and a spring material.

Normally, the outer pipe constituting the exhaust pipe of the exhaust pipe joint is fixedly connected to the muffler side, and the inner pipe forming the exhaust pipe connected to the outer pipe is connected to the engine side. It is not limited to. As a cylindrical gasket,
The material is not particularly limited as long as it is easily deformed when compressed and has heat resistance.For example, a reinforcing material made of a wire mesh obtained by weaving or knitting a thin metal wire such as stainless steel, and an expansion material A suitable example is obtained by laminating a heat-resistant sheet such as graphite, mica, etc., winding this into a cylindrical shape to form a preform, and compressing the preform in the axial direction. be able to.

[0009]

As described above, the exhaust pipe joint of the present invention is generally used by connecting the outer pipe to the muffler side and the inner pipe to the engine side. The cylindrical gasket disposed in the annular space between the outer peripheral surface of the end of the inner tube and the inner peripheral surface of the enlarged end of the outer tube is pressed and compressed by the pressing and fixing means in the annular space. As a result, the annular space is tightly filled by the cylindrical gasket, so that leakage of exhaust gas can be prevented immediately after assembly. Since the pressing member is elastically deformed by the tightening of the tightening band, and the cylindrical gasket is pressed and compressed in the annular space, the cylindrical gasket is uniformly pressed and compressed in the annular space. Further, since the enlarged end of the outer tube is pressed and fixed to the enlarged portion of the inner tube by tightening the tightening band, relative vibration is hardly generated between the outer tube and the inner tube. Damage to the cylindrical gasket due to vibration between the inner gasket and the inner tube is prevented.

Next, the present invention will be described in more detail with reference to a preferred embodiment shown in the drawings. The present invention is not limited to these specific examples.

[0011]

1 to 4 show an exhaust pipe joint 1 of this embodiment.
Is an outer tube 5 having an outer tube main body 2 and an enlarged diameter end 4 connected to the outer tube main body 2 via a shoulder 3, and an end 6 inserted into the enlarged diameter end 4 of the outer tube 5. And an inner tube 11 having an enlarged diameter portion 10 connected to the end portion 6 via a shoulder portion 9 and inserted into the enlarged diameter end portion 4 of the outer tube 5, and an outer peripheral surface 12 of the end portion 6 of the inner tube 11. A cylindrical gasket 15 disposed in an annular space 14 between the inner peripheral surface 13 of the outer tube 5 and the inner peripheral surface 13 of the outer tube 5, and the cylindrical gasket 15 is directed along the pipe axis A and toward the shoulder 3 of the outer tube 5. Press and fixing means 16 for pressing and fixing the outer tube 5 to the inner tube 11.

The inner tube 11 of this embodiment comprises an inner tube main body 21 having a small diameter, the aforementioned end portion 6 and the enlarged diameter portion 10, and the inner tube main body 21 and the end portion 6 are formed to have the same diameter. The inner tube main body 21 does not need 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 enlarged diameter portion 10, for example. The inner pipe main body 21 and the enlarged diameter portion 10 are connected via a shoulder 22.

The pressing and fixing means 16 includes a pair of split grooves 31 and 3 formed on the enlarged diameter end 4 so as to extend along the tube axis A.
2, an enlarged end 33 provided at the enlarged end 4 as a locking portion on the outer tube 5 side, and an inner tube extending outside the outer tube 5 through each of the pair of cut grooves 31 and 32. A pair of inverted L-shaped fittings 34 as locking portions on the side of the inner pipe 11 provided by being fixed to the enlarged diameter portion 10 by welding, one end 35 abuts the base of the enlarged diameter end 33, and the other end 36. Are pressed against the L-shaped fitting 34 and are disposed on the outer peripheral surface of the enlarged diameter end portion 4.
And a tightening band 38 for tightening and holding 7 at the enlarged diameter end portion 4.

Although the two split grooves 31 and 32 in this embodiment are formed symmetrically with respect to the tube axis A, two or more split grooves 31 and 32 may be provided, for example, three. In this case, although not particularly limited, 120
It is preferable to provide them at equal angular intervals, and in this case, it is preferable to provide the inverted L-shaped bracket 34 correspondingly. The engaging portion on the outer tube 5 side may be embodied by an enlarged end 33 formed by enlarging the distal end of the enlarged end 4 as in this example.
Instead of this, for example, a flange member or a fitting equivalent to the inverted L-shaped fitting 34 is integrally formed or fixed to the end of the enlarged diameter end 4 by welding or the like to realize the locking portion on the outer tube 5 side. You may.

The tightening band 38 includes a band body 51,
The band main body 5 is formed integrally with the band main body 51.
A pair of opposed ears 52 and 53 bent outwardly with respect to 1, a bolt 56 inserted through through holes 54 and 55 formed in the ears 52 and 53, and screwed into the bolt 56. The pressing member 37 is fastened to the outer peripheral surface of the enlarged diameter end portion 4 by reducing the diameter of the band main body 51 by screwing the bolt 56 to the nut 57.

The cylindrical gasket 15 is pressed by the pressing member 37 toward the shoulder 3 of the outer tube 5 via the shoulder 9, and the pressing member 37 has an elongated length in the direction along the pipe axis A. So that it is elastically deformed by the tightening of the tightening band 38. The pressing member 37 of this example is formed of an end ring having opposed ends 61 and 62, and its shape before tightening is an arc-shaped cross section as shown in FIG. As shown in FIG. 1, the elastic member is elastically deformed into a flat cross section by the tightening of 38.
The enlarged end 4 of the outer tube 5 is pressed and fixed to the outer peripheral surface of the enlarged portion 10 of the inner tube 11 by tightening the tightening band 38.

The exhaust pipe joint 1 configured as described above is assembled and manufactured as follows. That is, as shown in FIG. 5, first, the outer tube main body 2, the enlarged-diameter end portion 4 connected to the outer tube main body 2 via the shoulder portion 3, and the extended-diameter end portion 4 are formed to extend along the pipe axis A. Outer tube 5 having a pair of cut grooves 31 and 32 and an enlarged end 33 provided at the enlarged end 4.
End portion 6 into which cylindrical gasket 15 is press-fitted and inserted, enlarged diameter portion 10 and enlarged diameter portion 1 connected to end portion 6 via shoulder 9.
0, a pair of inverted L-shaped fittings 3 secured by welding
4 are prepared.

Next, the end 6 with the cylindrical gasket 15 inserted therein and the enlarged diameter portion 10 are separated from each other by a pair of inverted L-shaped fittings 34 through the pair of slits 31 and 32, respectively. And the cylindrical gasket 15 is disposed in the annular space 14 between the outer peripheral surface 12 of the end 6 and the inner peripheral surface 13 of the enlarged end 4 so as to be inserted into the enlarged end 4 and expanded. A pressing member 37 that is elastically deformable in the direction of the tube axis A is disposed on the outer peripheral surface of the enlarged diameter end portion 4 between the radial end 33 and the inverted L-shaped bracket 34, and a bolt 56 is screwed into a nut 57 and tightened. As a result, the tightening band 38 disposed on the outer peripheral surface of the pressing member 37 is tightened, and the pressing member 37 is elastically deformed and stretched in the direction of the tube axis A by this tightening.
One end 35 of the pressing member 37 is brought into contact with the base of the enlarged-diameter end 33 and the other end 36 is brought into contact with the L-shaped bracket 34 so that the pressing member 37 is pressed in the direction shown in FIG. The enlarged diameter end portion 4 is pressed against the outer peripheral surface of the enlarged diameter portion 10,
Fix it.

In the exhaust pipe joint 1 of the present embodiment shown in FIG. 1 assembled and manufactured as described above, the cylindrical gasket 15 is brought into tight contact with the outer peripheral surface 12 and the inner peripheral surface 13 to fill the annular space 14 densely. Therefore, leakage of exhaust gas from the annular space 14 can be prevented as desired.

Further, in the exhaust pipe joint 1, the pressing member 37 is elastically deformed by tightening the bolt 56, whereby the enlarged diameter end 33 and the inverted L-shaped fitting 34 are separated from each other along the pipe axis A, and the shoulder portion is formed. 9, press the cylindrical gasket 15
Because of the compression deformation, the degree of compression deformation of the cylindrical gasket 15 can be made substantially the same in the circumferential direction without adjusting the degree of tightening of the bolt 56. In other words, in the exhaust pipe joint 1 of the present embodiment, it is necessary to adjust the degree of tightening of the bolt 56 in order to cause the cylindrical gasket 15 to undergo a compression deformation of a predetermined amount or more. To make the degree substantially the same in the circumferential direction, the tightening adjustment of the bolt 56 may not be necessary.

In the exhaust pipe joint 1, the enlarged diameter end 4 is pressed against and fixed to the outer peripheral surface of the enlarged diameter part 10, and the outer pipe 5 is connected to the inner pipe 11.
, The relative mutual vibration of the outer tube 5 and the inner tube 11 can be eliminated, and the cylindrical gasket 15 can be prevented from being deteriorated by the minute vibration of the shoulder portion 9.

In the above, the pressing member 3 having an arc-shaped cross section is used.
7, the pressing member 71 having a cross-sectional waveform as shown in FIG. 6 is elastically deformed by tightening the tightening band 38 in the same manner as described above, and the exhaust pipe joint 72 according to the present invention is formed. It may be formed. The cross-sectional waveform of the pressing member 71 shown in the figure has two peaks, but may have one or three or more peaks.

Further, as shown in FIGS. 7 and 8, a pressing member 77 composed of a pair of divided pieces 75 and 76 arranged opposite to each other with the tube axis A interposed therebetween is elastically deformed by tightening a tightening band 38. An exhaust fitting 78 according to the present invention may be formed. Here, each of the divided pieces 75 and 76 has a cross-sectional waveform having three peaks, and is fixed to the band main body 51 by spot welding at central portions 81 and 82 in the circumferential direction. When the pressing member 77 is fixed to the band main body 51 in this manner, assembling manufacturability can be further improved.

[0024]

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 leakage of exhaust gas can be preferably achieved. In addition, it is possible to prevent the cylindrical gasket from being damaged due to the vibration between the outer pipe and the inner pipe, and to provide an exhaust pipe joint having extremely excellent workability in manufacturing, disassembling and assembling.

[Brief description of the drawings]

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

FIG. 2 is a left side view of the outer tube shown in FIG.

FIG. 3 is a left side view of the inner pipe shown in FIG. 1;

FIG. 4 is a side view of the combination of the tightening band and the pressing member shown in FIG. 1 before tightening.

FIG. 5 is an explanatory diagram of an assembling / manufacturing method of the specific example shown in FIG. 1;

FIG. 6 is a sectional view showing another example of the pressing member according to the present invention.

FIG. 7 is a sectional view showing still another example of the pressing member according to the present invention.

FIG. 8 is a side view of the combined body of the tightening band and the pressing member shown in FIG. 7 before tightening.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Exhaust pipe joint 5 Outer pipe 11 Inner pipe 15 Cylindrical gasket 16 Pressing and fixing means

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F01N 7/08

Claims (8)

(57) [Claims] 1. An outer tube having an outer tube main body and an enlarged end connected to the outer tube main body via a shoulder, an end inserted into the enlarged end of the outer tube, and this end. An inner pipe having an enlarged diameter portion which is connected to the enlarged diameter end of the outer pipe through a shoulder, and an outer peripheral surface of an end of the inner pipe and an inner peripheral surface of the enlarged diameter end of the outer pipe. And a pressing and fixing means for pressing the cylindrical gasket along the pipe axis and toward the shoulder of the outer pipe, and for fixing the outer pipe to the inner pipe. An exhaust pipe joint, wherein the pressing and fixing means are provided at at least one pair of cut grooves formed along the pipe axis at the enlarged diameter end of the outer pipe and at the enlarged diameter end of the outer pipe. A locking part on the outer tube side,
An inner tube-side engaging portion that extends outside of the outer tube through each of the cut grooves and is provided at the enlarged diameter portion of the inner tube, one end of which contacts the outer tube-side engaging portion, and the other end of which is inward. A pressing member is provided on the outer peripheral surface of the enlarged diameter end of the outer tube in contact with the locking portion on the tube side, and a tightening band for tightening and holding the pressing member to the enlarged diameter end of the outer tube, The cylindrical gasket is pressed by the pressing member through the shoulder of the inner tube toward the shoulder of the outer tube. An exhaust pipe joint that has been elastically deformed by tightening, and the enlarged diameter end of the outer pipe is pressed and fixed to the enlarged diameter part of the inner pipe by tightening a tightening band. 2. The exhaust pipe joint according to claim 1, wherein the shape of the pressing member before the tightening is an arc-shaped cross section or a cross-sectional waveform. 3. The exhaust pipe joint according to claim 1, wherein the pressing member is fixed to the tightening band. 4. The exhaust pipe joint according to claim 1, wherein the pressing member comprises a pair of split pieces arranged to face each other with the pipe shaft interposed therebetween. 5. An outer tube main body, an enlarged end connected to the outer tube main via a shoulder, at least one pair of cut grooves formed at the enlarged end along the tube axis, and An outer pipe having a locking portion provided at the enlarged diameter end, an end at which the cylindrical gasket is inserted, an enlarged diameter portion connected to this end via a shoulder, and an enlarged diameter portion. An inner tube provided with each of the provided locking portions is prepared, and an end portion of the inner tube in which the cylindrical gasket is inserted and the enlarged diameter portion of the inner tube are provided. And the cylindrical gasket is disposed in the annular space between the outer peripheral surface of the end of the inner tube and the inner peripheral surface of the enlarged end of the outer tube through each of the outer tubes. A pressing member that is inserted into the enlarged diameter end of the outer tube and elastically deforms in the tube axis direction on the outer peripheral surface of the enlarged diameter end of the outer tube between the engagement portion on the outer tube side and the engagement portion on the inner tube side. Distribute Then, the tightening band disposed on the outer peripheral surface of the pressing member is tightened, and the tightening member elastically deforms the pressing member to extend in the tube axis direction. One end of the pressing member is brought into contact with the locking portion on the outer tube side and the other end is brought into contact with the locking portion on the inner tube side so that the pressing member is pressed toward the inner tube side. A method for manufacturing an exhaust pipe joint for pressing and fixing an enlarged end of a pipe to an enlarged diameter of an inner pipe. 6. The method for manufacturing an exhaust pipe joint according to claim 5, wherein the shape of the pressure fixing member before the tightening is an arc-shaped cross section or a cross-sectional waveform. 7. The method for manufacturing an exhaust pipe joint according to claim 5, wherein the pressing member is fixed to the tightening band in advance. 8. The exhaust pipe joint according to claim 5, wherein the pressing member comprises a pair of split pieces, and the pair of split pieces are arranged to face each other with the pipe axis interposed therebetween. Production method.