JPH11166412A - Exhaust system equipped with catalyst body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exhaust system equipped with a catalyst, body which is capable of facilitating masking in the process of catalyst carrying so as to reduce costs and increasing durability against the thermal stress deformation of the catalyst. SOLUTION: A supporting structure of a catalyst body 12 is made in such a manner that only the rear end part (example of one end part) 12r of the catalyst body 12 is used as a masking part 34 and a first stay 36 is welded and fixed to the rear end part 12r. By welding and fixing this first stay 36 to the rear side inner wall of a first hollow muffler part 10a, the rear end part 12r of the catalyst body 12 is fixed in the first muffler part 10a via the first stay 36. A second stay 38 is welded and fixed to the inner wall of the first muffler 10a, a supporting pipe 40 is welded and fixed by a second stay 38, the rear end part of the supporting pipe 40 is inserted into the front end part 12f of the catalyst body 12, and then supported so as to be movable.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a catalyst-equipped exhaust device provided with a pipe-type catalyst inside a muffler of a motorcycle, for example.

[0002]

2. Description of the Related Art Conventionally, in order to remove unburned components in exhaust gas, an exhaust system of a motorcycle has a pipe-type catalyst body in which a catalyst material is supported on a metal pipe material inside a muffler ("Pipe catalyst body"). "). As shown in FIGS. 6 and 7, in order to arrange and fix the axial direction of the pipe catalyzer a along the exhaust gas flow direction, stays b1 and b2 are provided at two positions separated from the front and back of the pipe catalyzer a. Was fixed by welding, and the outer ends of the stays b1 and b2 were fixed by welding to the inner wall of the muffler. FIG. 6 shows the outer shape of the muffler by reference numeral c. As shown in the sectional view of FIG. 7, a plurality of through holes d are formed in the pipe catalyst body a in order to allow exhaust gas to flow inside and outside the pipe catalyst body a. JP-A-5-195766 discloses an example of a mounting structure for supporting and fixing a pipe in a muffler.

[0003] Here, the pipe catalyst body a is a stay b1,
Since welding cannot be performed when the catalyst material is carried at the welding point b2, it is necessary to mask the areas e1 and e2 corresponding to the welding point to carry the catalyst material.

[0004]

However, when the catalyst material is supported on the pipe material, masking can be easily performed on the stay welded portion (corresponding to e1 in FIG. 6) at the end of the pipe material. Masking of the stay welded part (corresponding to e2 in FIG. 6) in the middle is very troublesome, and the processing work load is high, which causes an increase in cost.

[0005] That is, in the step of supporting the catalyst material on the pipe material, as shown in FIG. 8, the end of the pipe material is chucked and transferred by the holder f and dipped in a solution g containing a noble metal. This is because the masking must be strictly performed because the substantially central portion of the pipe material is completely immersed in the solution.

Further, the temperature of the catalyst material portion of the pipe catalyst body a becomes extremely high because the unburned gas undergoes an oxidation reaction. For this reason, the pipe material itself thermally expands, but at that time, stress is applied to a welded portion with the stay, which is likely to be a cause of reduced durability.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an exhaust device with a catalyst body, which can easily mask at the step of carrying a catalyst, can reduce the cost, and can improve the durability against thermal stress deformation of the catalyst.

[0008]

The present invention has the following configuration to achieve the above object. The invention of claim 1 is
In an exhaust device in which a catalyst body in which a catalyst material is supported on a pipe material is disposed in an exhaust passage, a first stay fixed to one end of the catalyst body as a masking portion is fixed to an inner wall of the exhaust passage. An exhaust device with a catalyzer, comprising a catalyzer support structure in which a support pipe is fixed by a second stay fixed to an inner wall of an exhaust passage, and the other end of the catalyzer is movably supported by the support pipe. It is. According to another aspect of the present invention, the support pipe may include a metal elastic body that urges the other end of the catalyst body toward one end.

According to the first aspect of the present invention, when disposing the catalyst body in the exhaust passage, the first stay fixed to one end of the catalyst body as a masking portion is fixed to the inner wall of the exhaust passage. Then, the support pipe is fixed by the second stay fixed to the inner wall of the exhaust passage, and the other end of the catalyst body is movably supported by the support pipe, so that one end of the catalyst body is fixed by the stay. The other end has a support structure movably supported by a support pipe (floating support). Therefore, the catalyst body only needs to be masked at one end and fixed by welding or the like, and since the other end is not welded, there is no need for masking. Therefore, since only one masking is required, the operation of carrying the catalyst can be simplified and the cost can be reduced. In addition, the catalyst body has one end fixed but the other end movable with respect to the support pipe. Even if the catalyst body undergoes thermal stress deformation such as thermal expansion, the stress that deforms the support pipe and the stay is reduced. Will not cause. Therefore,
An advantageous support structure against vibration and thermal stress deformation. In addition, if the support pipe is configured to have a metal elastic body that urges one end toward the other end of the catalyst body as compared with a configuration in which the support pipe is simply inserted into the catalyst body. As a result, wear between the support pipe and the catalyst body due to vibration is reduced, and the support pipe is securely returned to its original position when thermally expanded and subsequently contracted. This has a more advantageous structure.

[0010]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is an overall side view of a motorcycle on which an exhaust device 10 according to a first embodiment of the present invention is mounted, FIG. 2 is an overall side view of the exhaust device 10, and FIG. 3 is a perspective view of a catalyst body 12 according to the first embodiment. FIGS. 4 and 5 are vertical cross-sectional views illustrating the mounting structure of the catalyst body 12 of FIG. 3, and FIG. 5 is a vertical cross-sectional view illustrating the mounting structure of the catalyst body 12 according to the second embodiment of the present invention.

As shown in FIG. 1, the motorcycle has its entire rigidity supported by a vehicle body frame 16.
6, a head pipe 18 is fixed to the front part by welding. The front wheel 22f is supported on the head pipe 18 by a front fork 20 so as to be steerable. Also, the body frame 1
6, a rear fork 24 is provided at the lower rear with a pivot shaft 26.
, And a seat frame (not shown) extends rearward and upward below the rear seat. A rear wheel 22r is pivotally supported at a rear portion of the rear fork 24, and a seat 30 is mounted on an upper portion of the seat frame 28.

Further, the body frame 16 has two
The cycle engine 32 and the engine case 34 are suspended. The exhaust device 10 is connected to an exhaust port of the engine 32. The exhaust device 10 comes out of the front part of the engine 32, goes around to the lower part, passes under and below the pivot shaft 26, and passes through the side of the rear fork 24. Extend to. Reference numeral 44
Is a front screen, 46 is a headlamp, 48 is a front cowling, 50 is a body cowl, 52 is a fuel tank, 54 is a front fender, 56 is a rear fender, 58 is a side cover, 60 is a rear cover, 62 is a tail lamp, and 64 is an exhaust. It is a device suspension bracket.

As shown in FIG. 2, the exhaust device 10 has an exhaust pipe 10a having a leading end connected to an engine exhaust port.
1, the exhaust gas is exhausted from the tail pipe 10 b 1 through a substantially hollow first muffler portion 10 a having an expansion chamber structure to which the divergent cone 10 a 2, the trunk portion 10 a 3, and the convergent cone 10 a 4 are connected. And a second muffler section 10b for discharging. The catalyst body 12 is formed by supporting a catalyst material on a pipe material, and the first muffler portion 10
a, and is disposed substantially at the center of the exhaust gas flow direction, specifically, mainly over the divergent cone 10a2 and the trunk 10a3.

As shown in FIG. 3 and FIG.
Is supported at the rear end (an example of one end) 12 of the catalyst body 12.
The first stay 36 is welded and fixed to the rear end 12r using only r as a masking portion 34. And this first
Is fixed to the inner rear wall of the hollow first muffler section 10a by welding, so that the rear end 12
r is fixed in the first muffler section 10 via the first stay 36. The first stay 36 is formed by bending both end portions 36a, 36a of the substantially strip-shaped plate material in a right angle direction as welding fixing portions to the inner wall of the muffler portion 10, and forming the central portion 36b as a welding fixing portion of the catalyst body 12 on the outer wall of the catalyst body 12. It is formed by bending into an arc shape along.

A second muffler 10a is provided on the inner wall of the first muffler 10a.
Is fixed by welding, and the support pipe 40 (made of a normal metal pipe material not carrying a catalyst material) is fixed by welding with the second stay 38. This second stay 38
Are bent at right angles to the both end portions 38a, 38a of the substantially strip-shaped plate material as welding fixing portions to the inner wall of the first muffler portion 10, and extend along the outer wall of the support pipe 40 as the central portion 38b as welding fixing portions of the catalyst body 12. It is formed by bending into an arc shape. Then, the rear end portion 40r of the support pipe 40 is inserted into the front end portion 12f of the catalyst body 12, and is supported movably. In this case, the outer diameter of the rear end of the support pipe 40 is
The catalyst body 12 is formed to be less than the inner diameter of the front end portion 12f and is movable. Reference numeral 12a is a through hole for increasing the surface area of the catalyst body and for allowing exhaust gas to flow inside and outside.

In the mounting structure of the catalyst body 12 according to the second embodiment, as shown in FIG. 5, a flange portion 42 is welded and fixed to an outer peripheral portion of the support pipe 40, and a spring washer 43 is provided on the rear side of the flange portion 42. In the fitted state, the front end support pipe 40 is inserted into the front end 12 f of the catalyst body 12. Further, a spring washer 43 made of a metal elastic material is interposed between the front end portion 12f of the catalyst body 12 and the flange portion 42, and biases the catalyst body 12 rearward by the elasticity of the washer 43.

According to the above-described embodiment, when disposing the catalyst body 12 in the exhaust passage, the rear end portion 12r of the catalyst body 12 is fixed to the rear end portion 12r as the masking portion 34. 36 is fixedly welded to the inner wall of the first muffler section 10b, the support pipe 40 is fixed to the second stay 38 welded to the inner wall of the muffler 10b, and the support pipe 40 is inserted into the front end 12f of the catalyst body 12. And movably supported. That is, the rear end 12r of the catalyst body 12 is
The front end 12f is movably supported by a support pipe 40 (floating support).
It has a support structure.

Therefore, the catalyst body 12 may be masked only at the rear end portion 12r and fixed by welding or the like, and since the front end portion 12f is not welded, there is no need for masking.
Therefore, since only one masking is required, the operation of carrying the catalyst can be simplified and the cost can be reduced. Further, the catalyst body 12 has a rear end 12r fixed, but the front end 1r.
2f becomes movable with respect to the support pipe 40, so that even if the catalyst body 12 undergoes thermal stress deformation such as thermal expansion, it does not generate stress that deforms the support pipe 40 and the stays 36 and 38. Therefore, a support structure advantageous against vibration and thermal stress deformation is obtained.

In the second embodiment, the support pipe 40
Has a spring washer 43 that urges the front end portion 12f of the catalyst body 12 rearward, so that the support pipe 40 of the first embodiment can be compared with a structure in which the support pipe 40 is simply inserted into the catalyst body 12 by vibration. Abrasion between the catalyst body 12 is reduced, and the supporting position of the support pipe 40 with respect to the catalyst body is reliably returned to the original position when the support pipe 40 is thermally expanded and subsequently contracted, which is more advantageous against thermal stress deformation. Structure.

[0020]

As described above, according to the present invention, masking in the step of supporting the catalyst can be easily performed, the cost can be reduced, and the durability against thermal stress deformation of the catalyst can be improved.

[Brief description of the drawings]

FIG. 1 is an overall side view of a motorcycle on which an exhaust device according to an embodiment of the present invention is mounted.

FIG. 2 is an overall side view of the exhaust device.

FIG. 3 is a perspective explanatory view of a catalyst body according to the first embodiment.

FIG. 4 is an explanatory view of a vertical section of a catalyst body.

FIG. 5 is an explanatory longitudinal sectional view of a catalyst body according to a second embodiment.

FIG. 6 is an explanatory perspective view of a catalyst body according to a conventional exhaust device.

FIG. 7 is an explanatory view of a vertical section of the catalyst body of FIG. 6;

FIG. 8 is an explanatory diagram of a catalyst supporting step of a catalyst body.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Exhaust apparatus 12 Catalyst body 14 Exhaust apparatus 34 Masking part 36 First stay 38 Second stay 40 Support pipe 43 Spring washer

Claims (2)

[Claims] 1. An exhaust device in which a catalyst body in which a catalyst material is carried on a pipe material is disposed in an exhaust passage, wherein a first stay fixed to one end of the catalyst body as a masking portion is provided in the exhaust passage. It has a catalyst support structure in which the support pipe is fixed by a second stay fixed to the inner wall and fixed to the exhaust passage inner wall, and the other end of the catalyst is movably supported by the support pipe. Exhaust device with catalyst. 2. The exhaust device with a catalyzer according to claim 1, wherein the support pipe has a metal elastic body which urges the other end of the catalyzer toward one end.