JPH07286515A - Exhaust pipe joint and manufacture thereof - Google Patents

Abstract

PURPOSE:To prevent leakage of exhaust gas and increase workability of manufacture, assembly, and disassembly by providing a tubular gasket in an annular space between an outer peripheral surface of an end of an inner pipe and an inner peripheral surface of an expanded end of an outer pipe and pressing and compressing the tubular gasket by a belt-like member in an exhaust pipe joint to be used in automobile and the like. CONSTITUTION:An end 6 in which a tubular gasket 15 is inserted and an expanded portion 10 in an inner pipe 11 are inserted in an expanded end 4 of an outer pipe 5 in a condition in which a pair of reverse L-shaped metal fittings 34 are inserted into a pair of split grooves 31, 32 formed at the expanded end 4 of the outer pipe 5. Next, a belt-like member 37 in the shape of character C is provided on an outer periphery of the expanded end 4 between an expanded end 33 of the expanded end 4 and the reverse L-shaped metal fittings 34 to shrink the belt-like member 37 by tightening a bolt 56 and a nut 57. The tubular gasket 15 is pressed against a shoulder portion 3 of the expanded portion 10 through the shoulder portion 3 via the reverse L-shaped metal fittings 34 due to its deformation, and the expanded end l+ of the outer pipe 5 is shrunk and pressed and fixed on an outer peripheral surface of the expanded portion 10 to connect the pipes 1, 5.

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 in 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 Patent Application No. 3-88552 (Japanese Utility Model Publication No. 5-32718), a cylindrical gasket arranged in a space between an enlarged cylindrical portion of an outer tube and an outer surface of the inner tube is pressed along a tube axis by a pair of pressing pieces. Then, it is compressed and deformed, and the space is densely filled with a cylindrical gasket to fill 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 described above. We proposed an exhaust pipe joint designed to prevent damage to the cylindrical gasket due to the vibration of the cylinder.

[0003]

In the exhaust pipe joint according to the above-mentioned proposal, the initial purpose of preventing leakage of exhaust gas and preventing damage to the cylindrical gasket immediately after the joint is assembled to the exhaust pipe is preferable. It was confirmed that this can be achieved, but in the example specified therein, the pressing piece is moved by tightening a pair of bolts to compress the cylindrical gasket into the space between the enlarged cylindrical portion of the outer pipe and the outer surface of the inner pipe. Therefore, if the tightening degrees of the pair of bolts are different from each other, the degree of compressive deformation of the cylindrical gasket is different in the circumferential direction, and as a result, the prevention of exhaust gas leakage cannot be preferably achieved. It turned out to be a concern. 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 it is an object of the present invention that adjustment is unnecessary and the degree of compressive deformation of a cylindrical gasket can be made substantially the same in the circumferential direction. An exhaust pipe joint and a manufacturing method thereof, 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 have extremely excellent workability in manufacturing and disassembling and assembling. To provide.

[0005]

According to the present invention, the object is to provide an outer tube main body and an outer tube having an enlarged diameter end connected to the outer tube main body via a shoulder, and to expand the outer tube. An inner pipe having an end portion inserted into the radial end portion and an enlarged diameter portion connected to this end portion via a shoulder portion and inserted into the enlarged diameter end portion of the outer pipe, and an outer circumference of the end portion of the inner pipe. The cylindrical gasket disposed in the annular space between the surface and the inner peripheral surface of the expanded 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 including a pressing and fixing means for fixing to a pipe, wherein the pressing and fixing means includes at least a pair of slit grooves formed along the pipe axis at an enlarged end portion of the outer pipe. , The outer pipe side locking portion provided at the outer diameter expanded end portion of the outer pipe and the inner pipe side extending through the slits to the outside of the outer pipe and provided on the inner diameter expanded portion of the inner pipe. A stopper, one end of which is in contact with the outer pipe-side locking portion and the other end of which is in contact with the inner pipe-side locking portion and which is arranged on the outer peripheral surface of the expanded pipe end of the outer pipe; And a tightening means provided at an end portion of the band-shaped member for tightening the band-shaped member to the expanded diameter end portion of the outer tube, wherein the cylindrical gasket has a shoulder portion of the outer tube via the shoulder portion of the inner tube by the band-shaped member. The strip-shaped member is elastically deformed by the tightening of the tightening means so that the length in the direction along the tube axis of the strip-shaped member is extended. This is achieved by an exhaust pipe joint that is pressed and fixed to the expanded diameter portion of the inner pipe by tightening.

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,
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 inner pipe provided with an enlarged diameter portion connected to this end portion via a shoulder portion and an engaging portion provided on the enlarged diameter portion, respectively, and an inner pipe having a cylindrical gasket inserted therein. Between the end portion and the enlarged diameter portion of the inner pipe, the inner pipe side locking portion extends to the outside of the outer pipe through each of the slit grooves, and the cylindrical gasket expands the outer peripheral surface of the end portion of the inner pipe and the outer pipe. It is inserted in the expanded end of the outer pipe so that it is arranged in the annular space between the inner peripheral surface of the radial end and the outer pipe-side locking part and the inner pipe-side locking part. On the outer peripheral surface of the expanded end of the outer tube, a band-shaped member that is elastically deformable in the pipe axis direction is arranged, and this band-shaped member is tightened, and the band-shaped member is elastically deformed by this tightening. Extend in the tube axis direction, abutting one end of the band-shaped member on the outer tube side locking portion so that the cylindrical gasket is pressed toward the shoulder portion of the outer tube through the shoulder portion of the inner tube. Achieved by a method of manufacturing an exhaust pipe joint in which the end is brought into contact with a locking portion on the inner pipe side, and the enlarged diameter end portion of the outer pipe is pressed and fixed to the enlarged diameter portion of the inner pipe through the band-shaped member by the tightening. To be done.

In the above exhaust pipe joint, as a shape of the belt-shaped member before tightening, an arcuate section or a corrugated section can be given as one preferable example. Particularly preferably, it has an arcuate cross section, but the present invention is not limited thereto.
Examples of the material of the belt-shaped member include steel, stainless steel, spring materials and the like. Each of the end portions of the belt-shaped member may be formed with an ear portion having a through hole, and the tightening means may be composed of a bolt arranged in the through hole of the ear portion and a nut screwed to the bolt. In this case, if the bolt can be rotated from the direction orthogonal to the tube axis, the workability of manufacturing and disassembling / assembling is further improved. Further, when the shape of the belt-shaped member before tightening is an arcuate section, etc., the width of the belt-shaped member near the ends is narrowed toward the ears, and the belt-shaped member is firmly tightened. You may do it.

Usually, the outer pipe constituting the exhaust pipe of the present exhaust pipe joint is fixed to the muffler side, and the inner pipe constituting the exhaust pipe connected to the outer pipe is fixed to the engine side. Not limited to. As a cylindrical gasket,
It is not particularly limited as long as it is a material that is easily deformed when compressed and has heat resistance, but for example, a reinforcing material composed of a wire mesh obtained by weaving or knitting metal thin wires such as stainless steel and expansion, A preferred example is one in which a heat-resistant sheet such as graphite or mica is superposed, and this is wound into a cylindrical shape to form a preform, and then the preform is axially compressed and manufactured. be able to.

[0009]

As described above, the exhaust pipe joint of the present invention is usually used by connecting the outer pipe to the muffler side and the inner pipe to the engine side. Since the cylindrical gasket arranged in the annular space between the outer peripheral surface of the end portion of the inner pipe and the inner peripheral surface of the expanded diameter end portion of the outer pipe is pressed and compressed in the annular space by the band-shaped member, As a result of the annular space being tightly filled by the cylindrical gasket, exhaust gas leakage can be prevented immediately after assembly. Then, the band-shaped member is elastically deformed by the tightening of the tightening means, and since the cylindrical gasket is pressed and compressed in the annular space, the cylindrical gasket is uniformly pressed and compressed in the annular space. Furthermore, the expanded end of the outer pipe is pressed and fixed to the expanded part of the inner pipe by tightening the strip-shaped member, so relative vibration does not easily occur between the outer pipe and the inner pipe, and the outer pipe The cylindrical gasket is prevented from being damaged due to the vibration between the inner pipe and the inner pipe.

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

[0011]

SPECIFIC EXAMPLE Exhaust pipe joint 1 of this example in FIGS. 1 to 4
Is an outer tube 5 having an outer tube body 2 and an enlarged diameter end 4 connected to the outer tube body 2 via a shoulder portion 3, and an end portion 6 inserted into the enlarged diameter end 4 of the outer tube 5. And an inner pipe 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 pipe 5, and an outer peripheral surface 12 of the end portion 6 of the inner pipe 11. And a cylindrical gasket 15 disposed in the annular space 14 between the inner peripheral surface 13 of the expanded end portion 4 of the outer tube 5 and the cylindrical gasket 15 along the tube axis A and toward the shoulder portion 3 of the outer tube 5. And a fixing means 16 for fixing the outer pipe 5 to the inner pipe 11.

The inner pipe 11 of this embodiment comprises an inner pipe body 21 having a small diameter, the end portion 6 and the enlarged diameter portion 10 described above, and the inner pipe body 21 and the end portion 6 are formed to have the same diameter. The inner tube body 21 does not have to have the same diameter as the end portion 6 as in this example,
For example, the diameter may be the same as that of the expanded diameter portion 10. The inner tube body 21 and the expanded diameter portion 10 are connected to each other via a shoulder portion 22.

The pressing and fixing means 16 has a pair of slit grooves 31 and 3 formed along the tube axis A at the expanded end portion 4.
2, an enlarged diameter end 33 as a locking portion provided on the enlarged diameter end 4 on the outer pipe 5 side, and a pair of slit grooves 31 and 32, respectively, and extends outside the outer pipe 5 and extends to the inner pipe. A pair of inverted L-shaped metal fittings 34 as locking parts on the side of the inner pipe 11 fixedly attached to the expanded diameter portion 11 of the inner pipe 11 by welding, one end 35 abuts on the base of the expanded diameter end 33, and the other end 36 Is provided on the end portion 38 of the strip-shaped member 37 for tightening the strip-shaped member 37 on the enlarged-diameter end portion 4 and the strip-shaped member 37 arranged on the outer peripheral surface of the enlarged-diameter end portion 4 in contact with the inverted L-shaped metal fitting 34. And tightening means 39.

Although the two slits 31 and 32 in this embodiment are formed symmetrically with the tube axis A in between, two or more slits 31 and 32 may be provided, for example, three slits. At this time, although not particularly limited, 120 in the circumferential direction
It is preferable to provide them at equal angular intervals, and in this case, it is preferable to provide the inverted L-shaped metal fittings 34 correspondingly. The locking portion on the outer tube 5 side may be embodied by the enlarged diameter end 33 formed by expanding the tip of the enlarged diameter end portion 4 as in this example.
Instead of this, for example, a flange member or a metal fitting equivalent to the inverted L-shaped metal fitting 34 is integrally formed by welding or the like or fixed to the tip of the expanded diameter end 4 to embody the locking portion on the outer pipe 5 side. May be.

The belt-shaped member 37 includes a belt main body 51 and a belt main body 5.
A pair of opposed ears 52 and 5 that are integrally formed at one end and are bent outward with respect to the band body 51.
3 and a through hole 54 in the ears 52 and 53.
And 55 are formed. The band main body 51 is formed so that its width becomes narrower toward the ears 52 and 53 near the ends thereof.

The tightening means 39 of this embodiment is provided with a bolt 56 inserted through the through holes 54 and 55 and a nut 57 screwed into the bolt 56. The bolt 56 is screwed into the nut 57. By reducing the diameter of the band body 51, the band body 51 is fastened to the outer peripheral surface of the enlarged diameter end portion 4.

The cylindrical gasket 15 is pressed by the band main body 51 toward the shoulder 3 of the outer tube 5 via the shoulder 9, and the band main body 51 is elongated in the direction along the tube axis A thereof. As described above, it is elastically deformed by the tightening of the tightening means 39. The shape before tightening of the belt main body 51 of this example is shown in FIG.
As shown in FIG. 3, the band main body 51 having an arcuate cross section is elastically deformed into a flat plate cross section as shown in FIG. 1 by tightening the tightening means 39. The enlarged diameter end portion 4 of the outer pipe 5 is pressed and fixed to the outer peripheral surface of the enlarged diameter portion 10 of the inner pipe 11 by tightening the tightening means 39.

The exhaust pipe joint 1 configured as described above is assembled and manufactured as follows. That is, as shown in FIG. 6, first, the outer tube body 2, the radially expanded end portion 4 connected to the outer tube body 2 through the shoulder portion 3, and the radially expanded end portion 4 extending along the tube axis A are formed. Tube 5 having a pair of cut grooves 31 and 32 and an enlarged diameter end 33 provided on the enlarged diameter end 4 respectively.
And the end portion 6 into which the cylindrical gasket 15 is press-fitted, and the enlarged diameter portion 10 and the enlarged diameter portion 1 connected to the end portion 6 via the shoulder portion 9.
A pair of inverted L-shaped metal fittings 3 fixedly welded to 0
An inner tube 11 including 4 is prepared.

Next, the end portion 6 into which the cylindrical gasket 15 is inserted and the expanded diameter portion 10 pass through the pair of inverted L-shaped metal fittings 34 through the pair of slit grooves 31 and 32, respectively, and outside the outer pipe 5. The cylindrical gasket 15 extends into the annular space 14 between the outer peripheral surface 12 of the end portion 6 and the inner peripheral surface 13 of the expanded diameter end portion 4, and is inserted into the expanded diameter end portion 4 and expanded. A band-shaped member 37 which is elastically deformable in the direction of the pipe axis A is arranged on the outer peripheral surface of the enlarged diameter end portion 4 between the radial end 33 and the inverted L-shaped metal fitting 34, and the bolt 56 is screwed into the nut 57 and tightened. Thereby tightening the band-shaped member 37, elastically deforming the band main body 51 by this tightening and extending in the tube axis A direction, so that the cylindrical gasket 15 is pressed toward the shoulder 3 via the shoulder 9. Body 5
One end 35 of 1 is brought into contact with the base of the expanded diameter end 33, and the other end 36 is brought into contact with the L-shaped metal fitting 34, and the expanded diameter end 4 of the outer tube 5 is fixed by the diameter reduction of the band main body 51 due to the tightening. The diameter is reduced, and this is pressed and fixed to the outer peripheral surface of the enlarged diameter portion 10.

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 closely pressed against the outer peripheral surface 12 and the inner peripheral surface 13 to densely fill the annular space 14. Therefore, the leakage of the exhaust gas from the annular space 14 can be prevented as desired.

Further, in the exhaust pipe joint 1, the band member 37 is elastically deformed by tightening the bolt 56, so that the expanded diameter end 33 and the inverted L-shaped metal fitting 34 are separated from each other along the pipe axis A, and the shoulder portion. Press the cylindrical gasket 15 through 9,
Since the compression deformation is performed, the compression deformation degree of the cylindrical gasket 15 can be made substantially the same in the circumferential direction without adjusting the tightening degree of the bolt 56. In other words, in the exhaust pipe joint 1 of the present example, it is necessary to adjust the degree of tightening of the bolts 56 in order to cause the cylindrical gasket 15 to be compressed and deformed by a predetermined amount or more. In order to make the degree substantially the same in the circumferential direction, the tightening adjustment of the bolt 56 may be unnecessary.

In the exhaust pipe joint 1, the expanded diameter end 4 is pressed against and fixed to the outer peripheral surface of the expanded diameter portion 10, and the outer pipe 5 is fixed to the inner pipe 11.
Since the outer pipe 5 and the inner pipe 11 are fixed to each other, it is possible to eliminate the relative mutual microvibration, and it is possible to prevent deterioration of the cylindrical gasket 15 due to the microvibration of the shoulder portion 9.

By the way, in the above description, the strip-shaped member 3 having an arcuate cross section is used.
Although 7 is elastically deformed, the exhaust pipe joint 72 according to the present invention may be formed by elastically deforming the band-shaped member 71 having a corrugated cross section as shown in FIG. 7 in the same manner as described above. The sectional waveform of the belt-shaped member 71 shown in the figure has two peaks, but the number of peaks may be one or three or more.

[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 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 sectional view of a 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 tube shown in FIG.

FIG. 4 is a side view of the belt-shaped member and the fastening means shown in FIG.

FIG. 5 is a front view of the belt-shaped member and the tightening means shown in FIG.

FIG. 6 is an explanatory view of the assembly manufacturing method of the specific example shown in FIG.

FIG. 7 is a cross-sectional view showing another example of the belt-shaped member according to the present invention.

[Explanation of symbols]

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

Claims (8)

[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 shoulder via a shoulder and is inserted into the diameter-increased end of the outer pipe; Exhaust comprising: 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 and toward the shoulder of the outer tube and fixing the outer tube to the inner tube. In the pipe joint, the pressing and fixing means includes at least a pair of slit grooves formed along the pipe axis at the enlarged diameter end portion of the outer pipe, and an outer diameter provided at the enlarged diameter end portion of the outer pipe. The locking part on the tube side, the locking part on the inner tube side that extends outside the outer tube through each of the slits and is provided on the expanded diameter part of the inner tube, and the locking part on one end is the outer tube side. Abut the other A strip-shaped member whose end abuts on the locking portion on the inner pipe side and is arranged on the outer peripheral surface of the expanded-diameter end of the outer pipe, and an end of the strip-shaped member for tightening the strip-shaped member to the expanded-diameter end of the outer pipe. The cylindrical gasket is pressed by the belt-shaped member toward the shoulder portion of the outer tube through the shoulder portion of the inner tube, and the belt-shaped member is in a direction along the tube axis thereof. The exhaust pipe joint is elastically deformed by tightening the tightening means so that the length of the outer pipe is extended, and the expanded end of the outer pipe is pressed and fixed to the expanded part of the inner pipe by tightening the strip-shaped member. . 2. The exhaust pipe joint according to claim 1, wherein the shape of the belt-shaped member before tightening is an arcuate section or a corrugated section. 3. An end portion having a through hole is formed at each of the end portions of the band-shaped member, and the tightening means is a bolt arranged in the through hole of the ear portion and screwed to the bolt. The exhaust pipe joint according to claim 1 or 2, further comprising a nut. 4. The exhaust pipe joint according to claim 3, wherein the width of the end portion of the strip-shaped member is narrower toward the ear. 5. An outer tube main body, a diameter-expanded end connected to the outer tube main body via a shoulder, and at least a pair of slit grooves formed along the tube axis at the diameter-expanded end. 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 pipe having the respective locking portions provided is prepared, and the end portion of the inner pipe into which the cylindrical gasket is inserted and the enlarged diameter portion of the inner pipe are divided into slits by the locking portions on the inner pipe side. The outer pipe and the cylindrical gasket is disposed in the annular space between the outer peripheral surface of the end portion of the inner pipe and the inner peripheral surface of the enlarged diameter end portion of the outer pipe. The strip-shaped member that is inserted into the expanded end portion of the outer pipe and is elastically deformable in the axial direction of the pipe on the outer peripheral surface of the expanded end portion of the outer pipe between the outer pipe-side locking portion and the inner pipe-side locking portion. Distribute Then, the band-shaped member is tightened, the band-shaped member is elastically deformed by this tightening and stretched in the pipe axis direction, so that the cylindrical gasket is pressed toward the shoulder of the outer pipe through the shoulder of the inner pipe, One end of the strip-shaped member is brought into contact with the locking portion on the outer pipe side, and the other end is brought into contact with the locking portion on the inner pipe side. A method for manufacturing an exhaust pipe joint, in which the pipe is pressed and fixed to the expanded portion of the pipe. 6. The method of manufacturing an exhaust pipe joint according to claim 5, wherein the shape of the belt-shaped member before tightening is an arcuate section or a corrugated section. 7. The exhaust pipe joint according to claim 5, wherein each of the end portions of the strip-shaped member is formed with an ear portion having a through hole, and the strip-shaped member is fastened by bringing the ear portions close to each other. Manufacturing method. 8. The exhaust pipe joint according to claim 7, wherein the width of the vicinity of the end of the strip-shaped member becomes narrower toward the ear.