|Title of Invention||
A DETACHABLE MOUNTING ARRANGEMENT FOR CATALYTIC CONVERTER FOR ALL TWO-WHEELERS
|Abstract||A detachable mounting arrangement (system) for (replaceable) catalytic converter for all two-wheelers, wherein the exhaust pipe comprises of two halves, one half (first half) of which is rigidly and detachably fitted (connected) between an exhaust gas passage of engine- and remaining other half (second half) of the exhaust pipe, a mantle permanently carrying the catalytic converter is rigidly and detachably fitted in either first half or second half of the exhaust pipe or both (partly in each of said two halves), and an external sleeve is rigidly and detachably fastened on a part which is rigidly fitted on the outer periphery of said connecting end part of at least anyone of said halves of the exhaust pipe so as to firmly connect these said two halves of the exhaust pipe together, wherein said detachable connections of said two halves of the exhaust pipe together; is implemented only after fitting said catalytic converter mantle in the exhaust pipe and the detachment of said ca,lytic converter mantle from the exhaust pipe (for its replacement as required) is also facilitated by the dismantling of said two halves of the exhaust pipe from each other.|
|Full Text||This invention relates i" a detachable mounting arrangement for catalytic converter for all two- wheelers.
As known, catalytic converter is utilized in automobile purpose for
reducing or controlling the hazardous pollutants from the engine-exhaust
gas- In one kind of conventional arrangement, the catalytic converter is
irreplaceabfy welded (for permanently fitting) inside the muffler or the
exhaust pipe of any two-wheeler so far, During its manufacture, this
permanent fitting causes many problems as following: The possibilities
of rejection or damaging of the catalytic converter may be inevitable,
since the catalytic converter is so far capable of being assembled only
before the end of line-assembly; incapable of permitting any finishing
process such as electro-chemical process or chromium plating and the
like, carried out on the external surface of the muffler or exhaust-pipe (in
which said catalytic converter >s permanently fitted); C on sequent !ys
the external surface of exhaust pipe is not capable of being provided
with any aesthetic appeal ft also, has the following problems
during its service/maintenance: Impossibilities of replacement of
catalytic converter alone even as required; Due to the %ibrations of the vehicle on road, this welding joint may perhaps fail or crack thereby also calling for the whole replacement of the exhaust silencer; The whole replacement of its entire system
(of exhaust pipe with said catalytic converter) is inevitable, even after any one thereof (alone) is damaged or is to be serviced; Consequently, there is more recurring expenditure for the end user for maintenance thereof (due to this whole replacement).
On the other hand, in the vehicles other than the two-wheelers (4-wheelers, buses and the like), the catalytic converter is detachably fitted in the muffler having flange at least at one side thereof. The presence of the flanges causes the problems such as in size and appearance and the like. In addition, this is not employed for any two- wheeler so far. Moreover, its cost is significantly more than that of the permanent fitting of catalytic converter system with the muffler (said former system).
An object of this invention is to provide a detachable mounting arrangement (system) for replaceable catalytic converter for all two-wheelers to minimise its recurring expenditure for the end user for maintenance.
Another object of this invention is to reduce the cost for both manufacture and maintenance thereof.
A further object of this invention is to provide with better aesthetic features (appearances) or with compact size and shape.
With these and other objects in view, the present invention provides a detachable mounting arrangement for catalytic converter for nil two -wheelers, wherein the exhaust pipe comprises of two halves, first hall of which is rigidly and detachably fitted between an exhaust gas passage of engine-cylinder head and the second half of the exhaust pipe, a mantle permanently carrying the catalytic converter is rigidly and detachably fitted in either first haft or second half of the exhaust pipe or both partly in each of said two halves- and an externa! sleeve is rigidly and detachably fastened on a part which i% rigidly fitted on the outer periphery of wid connecting etui part of at leasi any one of said halves of the exhaust pipe so as to firmly connect these said two halves of the exhaust pipe together.
This invention will now be apparent from the following non-limitative description with reference to the accompanying drawings in which:
shows a view of a constructional example of a detachable mounting arrangement (system) for (replaceable) catalytic converter in an exhaust pipe of all two wheelers, along its axis;
FIGURE 2 shows an alternative example being a further modification of what is shown in FIGURE 1;
FIGURE 3 shows a second alternative example being
a further modification of what is shown in FIGURE 2;
FIGURE 4 shows a third alternative example for what is shown in FIGURE 1;
FIGURE 5 shows a fourth alternative example for what is shown in FIGURE 1.
Referring to the drawings, on the first half of the exhaust pipe 1 a collar 2 is welded on its outer periphery. A threaded boss 3 is also permanently welded on the front end-outer periphery of the second half of the exhaust pipe 4. A mantle 5 in the form of a cylindrical sleeve is having a mesh of catalytic converter or honeycomb structure 5A inside thereof (5) in the known way. A flange 5B provided in the form of a collar is either permanently and rigidly fitted on one free end of the outer periphery of said mantle 5 either by welding or by press fitting or made as an integral part of said mantle 5. The said mantle 5 is detachably fitted inside said second half of the exhaust pipe 4 wherein said flange 5B of said mantle 5 is detachably and firmly seated in an internal cylindrical step or an internal groove provided on the free end of said threaded boss 3. A sleeve nut 7 is loosely placed on the outer periphery of said first half of the exhaust pipe 1 and in front of said collar 2, before welding the same (2). The said sleeve-nut 7 is provided with an internal thread on its rear end so as to be fastened (or screwed) with an external thread provided on the outer periphery of the free end (or front end) of said threaded boss 3. A gasket 6 is placed between the free ends of both said collar 2 and said threaded boss 3 so as to air-tightly seal the gas leakage therebetween (2 and 3). The said sleeve-nut 7 is (tightly) fastened on said threaded boss 3 from its front end, wherein said collar 2 is firmly clamped against the
front end of said threaded boss 3 by said sleeve nut 7 so as to be axially and angularly secured with respect to said threaded boss 3.
According to this invention, the fastening of said sleeve-nut 7 on said threaded boss 3 is capable of being dismantled or unscrewed from each other to facilitate the easy detachment of said mantle 5 from said second half of the exhaust pipe 4. This is utilised for the replacement of said mantle 5 with said catalytic converter 5 A alone as required, after any one thereof (alone) is damaged or to be serviced or completed in its operational life-span. Therefore, it significantly reduces the recurring expenditure for the end user also for its maintenance.
Any finishing operation such as buffing, chemical or electro-chemical process is also allowable on the exhaust pipe or muffler body before the main assembly of said mantle 5 with said catalytic converter 5A inside of said exhaust pipe or muffler body 4. Consequently, said exhaust pipe or muffler body 4 even having said mantle 5 with said catalytic converter 5A is capable of being provided with any aesthetic appearance particularly on its external surface as required, like in convention. Since, the catalytic converter (5 and 5 A) is also capable of being assembled even after the end of line assembly, any rejection or damage to the catalytic converter is eliminated. Further, this mounting arrangement of said catalytic
converter (5 and 5A) in said exhaust pipe 4 will neither fail nor crack unlike the conventional welding joint, even due to any vibration of the vehicle on road.
Further, it is very compact in size and appearance unlike the conventional flanged mountings of the muffler having catalytic converter. Therefore, the external appearance of the whole arrangement of said exhaust pipe or with muffler is (are) almost in streamlined cylindrical structure, thereby enhancing better vehicle performance with nice appearance. These are the significant advantages of this invention over the conventional arrangements.
Further, as said both collar 2 and said threaded boss 3 are assembled together with the axial contact only (through said gasket 6), said sleeve nut 7 and said first half of the exhaust pipe 1 are mutually held by each other. This is subjected by axial load also with the bending moment. Also, the threaded joints between said sleeve nut 7 and said threaded boss 3 are subjected by any axial load with the bending moment. So, the assembly of said sleeve nut 7 with both said first half of the exhaust pipe 1 and said threaded boss 3 is also so strong as to withstand both the axial and bending loads.
Analogous parts in all the Figures (FIGURES 1 to 5) are given with the same reference symbols. For enhancing the stiffness
or the failure resistance of said threaded boss 3 against any bending
moment subjected between said first half of exhaust pipe 1 or said
second half of exhaust pipe 4, said threaded boss 3 A is modified as
shown in FIGURE 2. An additional internal cylindrical step -
adjoining with said first internal cylindrical step is provided on the -
free-end (or front-end) of threaded boss 3 A. The said collar 2 and
said gasket 6 are seated in said second internal cylindrical step of
threaded boss 3A so as to secure any bending moment between said
collar 2 and said threaded boss 3A. Now, said sleeve-nut 7A is
sufficient to only secure any axial moment between said collar 2 and
said threaded boss 3 A. ,
Further, a small axial clearance is provided between said sleeve-nut 7A and front-end (left-end as in the view) of said threaded boss 3A (even after tightly fastening or screwing said sleeve-nut 7A on said threaded boss 3A), so as to maintain sufficient axial clamping-gripness between said collar 2 and threaded boss 3A through said sleeve-nut 7A.
Still further, the total size of said sleeve-nut 7A along its axis is significantly smaller than that of said former sleeve-nut 7, since the total axial length of both said gasket 6 and the seating portion of said collar 2 inside of said threaded boss 3A is axially overlapping with the mating threads between said sleeve-nut 7A and
threaded boss 3A. Therefore, the assembly of said arrangement shown in FIGURE 2 is considerably compact in size along its axis.
Further, for enhancing both the compactness and the streamlined nature of said assembly respectively along diametrically and axially, both threaded boss 3B and sleeve-nut 7B respectively being the further modifications of said threaded boss 3A and said sleeve-nut 7A are provided as shown in FIGURE 3. In these, said threaded boss 3B is provided with third internal cylindrical step adjoining with said second internal cylindrical step. Further, said former external thread is replaced by an internal thread which is provided on the internal cylindrical step being on the free-end of said threaded boss 3B. In addition, said sleeve-nut 7B is provided with only an external thread on its rear-part and being the replacement of said former internal thread. This external thread of said sleeve-nut 7B is fastened or screwed with said internal thread of said threaded boss 3B. The axial length of said second internal cylindrical step is smaller than the sum of the axial length of both said collar 2 and said gasket 6 to provide an axial-clearance between the rear end of said sleeve-nut 7B and the internal annular face (which is adjoining between said second internal cylindrical step and said third internal cylindrical step) of said threaded boss 3B. Further, said sleeve-nut 7B is provided with a collar as an integral part thereof on its front end for being held by the fastening tool(s).
There is an axial clearance between the rear-end of said collar of said sleeve-nut 7B and front end of said threaded boss 3B to maintain sufficient axial clamping-gripness between said collar 2 and said threaded boss 3B.
This is diametrically more compactness in size and better-streamlined shape than the former features (being shown in FIGURES 1 and 2).
Further, in all the above features, said flange 5B is provided on the free-end of said mantle 5. (Due to said mantle 5 and said catalytic converter 5A), the load acting on said collar 5B is in the cantilever nature. For improving this nature of stiffness or failure resistance, the position of said flange 5C is dislocated from the free-end of said mantle 5 either to its middle part or to its middle-offset part as shown in FIGURE 4. In this, said mantle 5 is fitted partly in each of said two halves of the exhaust pipe 1 and 4.
Still further, as shown in FIGURE 5, said flange 5D might also be dislocated from both said front-end (as shown in FIGURES 1 to 3) and middle part (as shown in FIGURE 4) of said mantle 5 to its rear end. Now, said mantle 5 is fitted in said first half of the exhaust pipe 1. This embodiment shown in FIGURE 5 is employed for locating the known muffler baffles (not shown in
FIGURES) at the rear of said mantle 5 with compact size of the exhaust pipe with its muffler along its axis.
Further, said modified features described as in above with reference to each of the FIGURES 2 and 3, are also applicable to said modified features described as in above with reference to each of the FIGURES 4 and 5.
Moreover, said first half and second half of the exhaust pipe 1 and 4 might be referred as the exhaust pipe and the muffler-body in other embodiments (not shown in figures) for the different applications.
Any of the above features described is applicable for all the automobiles such as two-wheelers, four-wheelers and any other heavy-vehicles. It minimises the recurring expenditures for the end user for maintenance. It has also minimum cost for both manufacture and maintenance than the known exhaust system carrying the catalytic converter. It is capable of being finished to better aesthetic features (appearances) unlike the known system permanently carrying the catalytic converter. It is also more compact in size and shape than the known flanged system having detachable catalytic converter. These are the advantages of this system according to this invention.
The terms and expressions used herein are illustrative and not limitative in any sense.
|Indian Patent Application Number||417/MAS/1999|
|PG Journal Number||27/2007|
|Date of Filing||15-Apr-1999|
|Name of Patentee||M/S. TVS MOTOR COMPANY LIMITED|
|Applicant Address||JAYALAKSHMI ESTATES, 24 (OLD NO.8) HADDOWS ROAD, CHENNAI-600 006.|
|PCT International Classification Number||F 01 N-3/24|
|PCT International Application Number||N/A|
|PCT International Filing date|