JPH11218021A - Coupling device for automobile exhaust pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable damping force to be effectively obtained in relation to all movements in a simple configuration. SOLUTION: A bellows 14 is arranged in an about spherical cover 13 having two openings 13b, 13c. One end of the bellows 14 is fitted in and fixed to one opening 13b of the cover 13, and the other end of the bellows 14 is loosely fitted in the other opening 13c of the cover. A heat resistant fiber body 17 is arranged in a space formed by the inside surface of the cover 13 and the outside surface of the bellows 14. One exhaust pipe 3 is connected to one end of the bellows 14, and the other exhaust pipe 5 is connected to the other end of the bellows.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a joint device for an exhaust pipe of an automobile.

[0002]

2. Description of the Related Art Conventionally, in order to attenuate and absorb vibrations and the like from an internal combustion engine transmitted to an automobile exhaust pipe, the exhaust pipe is provided with a vibration absorbing joint device.

Conventionally, as a coupling device for such an exhaust pipe for automobiles, as shown in FIG. 10, an upstream exhaust pipe 101 and a downstream exhaust pipe 102 are connected by a bellows-type flexible pipe 103, and a conventional bellows-type flexible pipe 103 is used. A buffer member 104 is wound around the flexible tube 103, and a braider 1 made of a stainless steel wire mesh or the like is wound around the buffer member 104.
05 is wound slightly tightly, and a part of the buffer member 104 is press-fitted into the concave portion of the flexible tube 103.
It is disclosed in JP-A-6-4804. This is referred to as a first conventional technique.

As shown in FIG. 11, a spherical and rigid outer case 201 is connected to one exhaust pipe, and a spherical and smaller diameter outer casing 201 is connected to the other exhaust pipe. Connecting the inner case 202 formed in a rigid body,
A case in which the two cases 201 and 202 are arranged as shown in the figure with a buffer member 203 interposed therebetween is disclosed in, for example, Japanese Patent Application Laid-Open No. 8-35424. This is referred to as a second related art.

[0005]

In the first prior art, the joint itself is responsible for supporting the exhaust pipe after the joint while relaxing the bending vibration transmission of the exhaust pipe before and after the joint. Shear rigidity in the direction perpendicular to the axis cannot be provided. For this reason, there is a risk of breakage due to excessive shear input.

Further, when the joint is compressed in the axial direction, since the blader 105 is formed of a wire mesh or the like, it expands outward, so that the deformation of the cushioning member 106 in the diametric direction cannot be restrained. The damping effect against the compressive load and the stopper function cannot be expected. Therefore, there is a problem that an excessive load acts on the bellows 103, which is likely to cause deterioration and breakage.

On the other hand, in the second conventional technique, although the problems of the first conventional technique can be solved, the structure becomes complicated, and the problems of manufacturing difficulty, high cost, and increase in weight arise. In addition, there is also a problem that it is unavoidable to increase the size (deterioration of vehicle mountability) in response to a request to increase the amount of deformation of the buffer member 203 to increase the amount of attenuation.

Accordingly, an object of the present invention is to provide a joint device for an exhaust pipe for an automobile which solves the above-mentioned problems.

[0009]

According to a first aspect of the present invention, a bellows is disposed in a substantially spherical cover having two openings, and one end of the bellows is provided. Is fitted and fixed in one opening of the cover, the other end of the bellows is loosely fitted in the other opening of the cover, and a heat-resistant fibrous body is placed in a space formed by the inner surface of the cover and the outer surface of the bellows. An exhaust pipe coupling device for a vehicle, wherein one of the bellows is disposed, one exhaust pipe is connected to one end of the bellows, and the other exhaust pipe is connected to the other end.

In the present invention, when vibration, bending, compression, tension, shearing, or the like occurs between the two connected exhaust pipes, the fibrous body disposed between the valley of the bellows and the cover deforms. The movement of the bellows and the cover is greatly restricted, and a large damping force is generated for all the above movements.

According to a second aspect of the present invention, in the first aspect, the fibrous body is preliminarily formed by compression and then arranged in a space so as to be slidable with respect to the inner surface of the cover. In the present invention, the fibrous body is compressed in advance, so that a stronger damping force can be obtained. Also,
Pre-compression makes handling easier,
It is easy to assemble to the joint device.

According to a third aspect of the present invention, in the first or second aspect, the center of bending of the bellows and the spherical center of the cover coincide with each other. According to the present invention, furthermore, the bend of the bellows becomes natural at the time of bending between the two exhaust pipes, and the life of the bellows and the fibrous body is extended.

According to a fourth aspect of the present invention, in the first, second or third aspect, a pipe is externally fitted and fixed to an outer periphery of an end of the bellows on which the bellows is loosely fitted. At the end, a flange abutting on the outermost peak of the bellows is provided, the fibrous body is divided on both sides of the flange, and the density of the fibrous body outside the flange is set to be smaller than the density of the inner fibrous body. It is a big one.

Further, in the present invention, when the two exhaust pipes are pulled together, since the high-density fibrous body disposed outside is compressed by the flange, the fibrous body is relatively thin due to the restriction of the installation space. Even if it is formed, it exhibits a sufficient damping and stopper effect.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described based on an embodiment shown in the drawings. FIG. 1 shows an exhaust system showing an arrangement state of a joint device of the present invention. A joint device 4 of the present invention is connected to a downstream end of an upstream exhaust pipe 3 connected to an exhaust manifold 2 of an internal combustion engine 1, A downstream exhaust pipe 5 is connected to a downstream side of the joint device 4. The downstream exhaust pipe 5 is connected to a catalytic converter 6, a sub-muffler 7, and a main muffler 8, and the exhaust pipe is supported by supports 9 to 12 installed at the lower part of the vehicle floor.

A first embodiment of the joint device 4 will be described in detail with reference to FIGS. Cover 13 constituting joint device 4
Is formed in a substantially spherical shape in which a spherical portion 13a having a radius R whose center is O in FIG. 1 and openings 13b and 13c are formed on both sides thereof. Further, the cover 13 is formed rigidly by a metal plate. Furthermore, one opening 1 of the cover 13
One end 14a of the bellows 14 is fitted to the inner peripheral surface of the bellows 3b and fixed to the cover 13 by welding. Normally, the axis XX of the bellows 14 has the spherical center O of the spherical portion 13a of the cover 13 as described above. Pass through.

The bellows 14 is formed in a bellows-shaped flexible tube having a peak section 14b and a valley section 14c in the axial cross section, and the other end 14d projects outside from the other opening 13c of the cover 13. ing. A pipe 15 is fitted on the outer peripheral surface of the other end 14d of the bellows 14 and fixed by welding. The pipe 15 has a flange abutting on the outer surface of the outermost peak 14b of the bellows 14. 15a
Are bent.

The diameter of the other opening 13c of the cover 13 is determined by the cover 13 and the bellows 14,
More specifically, the bellows 14 is formed in a circular shape having a diameter larger than that of the tube 15 so as not to hinder the relative displacement of the tube 15 in the radial direction, and the other end 14 d of the bellows 14 is loosely fitted into the opening 13 c of the cover 13. I have.

Inside the bellows 14 is disposed an inner pipe 16 for preventing the exhaust gas from directly hitting the bellows 14 when the exhaust gas flows, and one end 16 of the inner pipe 16.
a is formed to have a large diameter, fitted to the inner peripheral surface of one end 14a of the bellows 14, and fixed by welding. The diameter of the main portion 16b of the inner tube 16 is slightly smaller than the valley 14c of the bellows 14 so that the main portion 16b does not interfere with the valley 14c of the bellows 14 when the joint is bent. The inner tube 16 is arranged so that its axis passes through the center of the spherical portion 13a at normal times, that is, concentric with the bellows 14.

A space formed by the inner surface of the cover 13 and the outer surface of the bellows 14 is filled with a heat-resistant fibrous body 17. As the fibrous body 17, for example, a heat-resistant wire mesh such as stainless steel fiber is used.

As shown in FIG. 2, the fibrous body 17 has its outer surface formed into a spherical surface along the inner surface of the cover 13 and its inner surface formed into an uneven surface along the valleys of the bellows 14 in advance. 14 and is arranged in the space between the cover 13 and the bellows 14. Further, as shown in FIG. 3, the fibrous body 17 is divided in the axial direction and is formed by two divided bodies 17a and 17b. Such division facilitates the attachment.

In the joint device 4 configured as described above, one end 16a of the inner pipe 16 is connected and fixed to the upstream exhaust pipe 3 by welding, and the other end 14d of the bellows 14 is connected to the downstream exhaust pipe 5
Are connected and fixed by welding.

Next, the operation of this embodiment will be described. Since the present joint device 4 has the above-described structure, when relative bending vibration (displacement) occurs between the exhaust pipes 3 and 5 before and after the joint device 4, minute amplitude vibration is generated. In this case, the bending of the bellows 14 is mainly performed, and in the case of a large amplitude vibration, the bending of the bellows 14 and the bending deflection of the fibrous body 17 are added together, and the friction between the bonding surfaces of the fibrous body 17 and the bellows 14 and the cover 13 is generated. The generated vibration damping force and the self-damping force due to the deformation (internal loss) of the fibrous body 17 are integrated to reduce or attenuate the vibration transmission between the front and rear of the joint device 4.

When the exhaust pipes 3 and 5 before and after the joint device 4 are relatively vibrated (displaced) in the axial direction, the load acting on the joint device 4 in the compression direction is reduced by the bellows 14 and the fibrous body. Vibration transmission is reduced by elastically deforming the combined structure of No. 17 in the compression direction. When the compressive force is large, both the cover 13 and the bellows 14 have high rigidity in the radial direction, so that the deformation of the fibrous body 17 in the radial direction is restricted, and a large compression reaction force is obtained in the axial direction.

As for the load for pulling the joint device 4 in the axial direction, the bellows 14 and the fiber
Is compressed in the axial direction and elastically deformed, thereby mitigating vibration transmission. Here, when the tensile force is large, as in the case where the compressive force is large, the fibrous body 17 is filled in a space having a structure with high rigidity in the radial direction, so that a large tensile reaction force is obtained in the axial direction.

The flange 15a formed on the pipe 15 of the joint device 4 has a function of dispersing a force for pressing the side surface of the peak portion 14b of the bellows 14 when a compressive force is applied to the joint device 4, Conversely, when a force in the pulling direction is applied, the fibrous body 17 between the rear surface of the flange 15a and the cover 13 is compressed, so that the function of a stopper against the axial displacement of the downstream exhaust pipe 5 can be exhibited. .

Also, by compressing the fibrous body 17 in advance by a predetermined amount to increase the density, a predetermined damping force can be obtained for each of the above forces, and the stronger the compressive force, the stronger the damping force. . In addition, by pre-compressing and forming into a desired shape in this way, assembling (manufacturing) of the joint measure 4 becomes easy.

Further, with the above configuration, the center of bending of the bellows 14 coincides with the spherical center of the cover 13, the bending of the bellows 14 becomes natural with respect to bending, and the life of the bellows 14 and the fibrous body 17 is extended.

FIGS. 4 and 5 show a second embodiment. Book second
In the embodiment, the fibrous body 17 in the first embodiment is divided into a plurality in the axial direction, in the example shown in FIG.
7c, 17d and 17e are arranged with a space 18 provided between them in the circumferential direction.

Since the other structure is the same as that of the first embodiment, the same parts are denoted by the same reference numerals and description thereof will be omitted. 6 to 8 show a third embodiment.

In the third embodiment, the fibrous body 17 is divided into inner and outer parts in the axial direction with the flange 15a as a boundary, and the inner fibrous body 17f is divided into a plurality of parts as shown in FIG. The outer fibrous body 17g is formed in an annular shape without being divided as shown in FIG. Further, the density of the outer fibrous body 17g is set higher than the density of the inner fibrous body 17f.

As described above, by increasing the density of the outer fiber body 17g, the flange 15a compresses the higher-density outer fiber body 17g during the above-mentioned pulling, and the outer fiber body 17g cannot be increased in the installation space. Even with the body 17g, sufficient damping force and stopper effect can be obtained with respect to a large tensile force.

The compression of the outer fibrous body 17g increases its rigidity.
And the force for supporting the downstream side exhaust pipe 5 via the airbag is further increased. Since other structures are the same as those of the first embodiment,
The same portions are denoted by the same reference numerals and description thereof will be omitted.

FIG. 9 shows a fourth embodiment. The fourth embodiment is an example in which the present invention is applied to a single exhaust pipe having two θ-shaped cross sections to form two flow paths. That is, the inner tube 16 in the third embodiment is connected to the main body 1.
6b is a shorter inlet pipe, and the other end 14d of the bellows 14
An outlet pipe 19 is welded and fixed to the pipe, and the leading ends of the two pipes 16 and 19 are wrapped around the center of the joint device 4 with a gap therebetween. , 2
1, two flow paths are formed in both pipes 16 and 19. In addition, a sandwiching plate 22 is provided in the inlet pipe 16, and the tip of the partition plate 21 of the outlet pipe 19 is inserted into this. A cover 13, a bellows 14, a pipe 15, and a flange 15 are provided outside the bellows 14 in the same manner as in the third embodiment.
a and fibrous bodies 17f and 17g. Note that a similar fibrous body may be filled in a gap formed by the sandwiching plate 22 and the partition plate 20 for improving airtightness.

In the fourth embodiment, the same functions and effects as in the third embodiment are exhibited.

[0036]

As described above, according to the first aspect of the present invention, it can be easily manufactured at low cost, and does not increase in weight, and is caused by vibration (displacement) generated between the two exhaust pipes. It is possible to provide a coupling device capable of generating a large damping force for all of bending, compression, pulling, and shearing movements. Furthermore, despite the simple structure, a large amount of deformation (attenuation) of the fibrous body can be secured.

According to the second aspect of the present invention, the damping force can be set as desired by the amount of compression of the fibrous body, and a stronger damping force can be obtained by increasing the amount of compression.
Further, the assembly of the fibrous body to the joint device is facilitated, and the manufacture of the joint device is facilitated.

According to the third aspect of the invention, the life of the bellows and the fibrous body can be further extended. Claim 4
According to the invention described above, further, when the two exhaust pipes are pulled together, a sufficient damping and stopper effect can be obtained even for the outer fibrous body that cannot be increased due to the restriction of the installation space.

[Brief description of the drawings]

FIG. 1 is a view showing an exhaust system in which a joint device of the present invention is arranged.

FIG. 2 is a side sectional view showing a first embodiment of the joint device of the present invention.

FIG. 3 is a sectional view taken along line AA in FIG. 2;

FIG. 4 is a side sectional view showing a second embodiment of the joint device of the present invention.

FIG. 5 is a sectional view taken along line BB in FIG. 4;

FIG. 6 is a side sectional view showing a third embodiment of the joint device of the present invention.

FIG. 7 is a sectional view taken along line CC of FIG. 6;

FIG. 8 is a sectional view taken along line DD of FIG. 6;

FIG. 9 is a side sectional view showing a fourth embodiment of the joint device of the present invention.

FIG. 10 is a side sectional view showing a conventional joint device.

FIG. 11 is a side sectional view showing a second conventional joint device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 4 ... Coupling apparatus 3,5 ... Exhaust pipe 13 ... Cover 13b, 13c ... Opening part 14 ... Bellows 14b ... Crest part 14c ... Valley part 15 ... Pipe 15a ... Flange 17 ... Fiber body 17f ... Inner fiber body 17g ... Outer Fibrous body

Claims (4)

[Claims] 1. A bellows is disposed in a substantially spherical cover having two openings, one end of the bellows is fitted and fixed to one opening of the cover, and the other end of the bellows is connected to the other end of the cover. The bellows is loosely fitted in the opening, a heat-resistant fibrous body is arranged in a space formed by the inner surface of the cover and the outer surface of the bellows, one exhaust pipe is connected to one end of the bellows, and the other exhaust pipe is connected to the other end. A joint device for an exhaust pipe for a vehicle, which is connected. 2. The cover according to claim 1, wherein the fibrous body is pre-compressed and arranged in a space, and is slidable with respect to the inner surface of the cover.
A coupling device for an exhaust pipe for a vehicle according to the above. 3. The joint device for an exhaust pipe for an automobile according to claim 1, wherein the center of bending of the bellows and the spherical center of the cover are matched. 4. A pipe is externally fitted and fixed to an outer periphery of an end of the bellows on which the bellows are loosely fitted, and a flange is provided at an end of the pipe so as to abut against an outermost peak of the bellows. The joint device for an exhaust pipe for a vehicle according to claim 1, wherein the fibrous body is divided on both sides, and the density of the fibrous body outside the flange is higher than the density of the fibrous body inside the flange.