Claims:FIELD OF THE INVENTION
[001] The present invention generally relates to a catalytic converter and more particularly to a housing for the catalytic converter.

BACKGROUND OF THE INVENTION
[002] A catalytic converter is a device installed in an exhaust system to reduce toxicity of exhaust gases. Typically, catalytic converters use catalysts such as platinum, palladium, or rhodium to oxidize carbon monoxide and unburned hydrocarbons, and reduce oxides of nitrogen. Even though present day catalytic converters eliminate upto 97% of carbon monoxide (CO) and hydrocarbon (HC) emissions, and in spite of usage of catalytic converters being made compulsory by various governments, there is still an exponential increase in the CO, nitrous oxides, HC and other harmful compounds.
[003] One inherent property of catalysts used in the converters is that the catalysts are not completely effective at low temperatures. Accordingly, once a catalytic converter reaches a desired temperature range, it is of utmost importance that the converter stays within the temperature range to facilitate the conversion for as long as the emissions are generated. In order to achieve the same, heat loss from the converter should be minimal.
[004] It has also been reported that more than 60% HC emissions can occur during “cold-start” period when the catalyst is at temperatures below its “lightoff” temperature and when the catalysts cool down due to loss of heat. Therefore, endeavors have been made in the past to quickly attain lightoff temperatures, thereby preventing heat loss of the catalytic converters.
[005] In one approach, the catalytic converter is heated electrically or with a catalyzed fuel burner. In this regard, the electric energy is supplied by an alternator or battery. Electrically heated converters typically require 1 to 2 kW for 20 to 40 seconds to reduce the cold start emissions. However, issues with this approach arose because energy from the battery could not be used to continuously supply energy for heat conversion and cope with the heat loss. Further problems were related to durability issues due to increased stress over the alternator or the battery, along with heating elements and connectors.
[006] In another approach, the converter is moved closer to an engine of a vehicle whereby heat generated by the engine can be transferred to the catalytic converter. However, this also posed multiple problems, one of which is additional unwanted heat being introduced into the engine compartment due to the heating of the converter. The additional heat further added to another problem of thermal degradation of engine components.
[007] In yet another approach, the converters are insulated by refractory materials like oxides of aluminum, silicon, magnesium etc. whereby heat loss is reduced and high temperatures can be maintained. However, such refractory insulation makes the converters extremely bulky and heavy causing problems in installation, serviceability, maintenance etc.
[008] In a further approach, converters are provided with two layers wherein one of the layers comprises of an HC adsorbent, while the other layer comprises of the catalyst. In this way, HCs entering the converters at low temperatures are adsorbed by the HC adsorbents. The HCs are then released by the adsorbents into the catalyst layer due to the gradual rise in the temperature. The HCs are then oxidized by the catalysts and are released. Although this approach seemed to be effective, the HCs released by the adsorbents have temperature in the range of 150oC – 200oC. Although these are high temperatures, they are much lower than the lightoff temperatures of the catalysts. Thus untreated HCs were eventually being released.
[009] Thus, there is a need in the art for a device that reduces heat loss from a catalytic converter and addresses at least the aforementioned problems.

SUMMARY OF THE INVENTION
[010] Accordingly, an aspect the present invention discloses a housing for a catalytic converter adapted to an exhaust pipe of a vehicle. The housing has a first end adapted adjacent to an inlet of the catalytic converter, and a second end adapted adjacent to an outlet of the catalytic converter. The housing extends between the first end and the second end thereby encasing the catalytic converter and creating an airtight space between an outer surface of the catalytic converter and an inner surface of the housing. In an embodiment of the invention, the housing has a cylindrical profile and circumferentially encases the catalytic converter.
[011] In an embodiment of the invention, the first end of the housing is adapted on a first hoop joining an effluent receiving portion of the exhaust pipe and the inlet of the catalytic converter. Further, the second end of the housing is adapted on a second hoop joining the outlet of the catalytic converter and an effluent releasing portion of the exhaust pipe.
[012] In another embodiment of the invention, the first end and the second end of the housing are welded on the first hoop and the second hoop respectively.
[013] In yet another embodiment of the present invention, the space between the outer surface of the catalytic converter and the inner surface of the housing is filled with air or glass wool. In another embodiment, a vacuum is created in the space between the outer surface of the catalytic converter and the inner surface of the housing. In a further embodiment of the invention, the housing is made of stainless steel. In an alternative embodiment, the housing is made of mild steel.
[014] Another aspect of the present invention discloses a motor vehicle having an engine and an exhaust pipe. In an embodiment of the invention, the engine is substantially vertically disposed with respect to a longitudinal axis of the motor vehicle. In another embodiment of the invention, the exhaust pipe extends frontwards from the engine. The exhaust pipe further turns obliquely downwards to an effluent receiving portion and subsequently extends rearwards from an effluent releasing portion towards a rear wheel along a longitudinal axis of the motor vehicle.
[015] In a further embodiment of the invention, the motor vehicle has a catalytic converter defined by an outer surface and an inner surface whereby the catalytic converter extends between an inlet and an outlet. Further, the inlet is coupled with the effluent receiving portion and the outlet is coupled with the effluent releasing portion. In this way the catalytic converter is obliquely disposed and offset to the longitudinal axis of the motor vehicle.
[016] In yet another embodiment of the present invention, the motor vehicle has a housing extending between a first end and a second end and encasing the catalytic converter having the first end adapted adjacent to the inlet of the catalytic converter and the second end adapted adjacent to the outlet of the catalytic converter, such that a space between the outer surface of the catalytic converter and an inner surface of the housing is created.

BRIEF DESCRIPTION OF THE DRAWINGS
[017] Reference will be made to embodiments of the invention, examples of which may be illustrated in accompanying figures. These figures are intended to be illustrative, not limiting. Although the invention is generally described in context of these embodiments, it should be understood that it is not intended to limit the scope of the invention to these particular embodiments.
Figure 1 shows an exemplary motor vehicle, in accordance with an embodiment of the invention.
Figure 2 shows an exploded view of the housing for a catalytic converter in accordance with an embodiment of the invention.
Figure 3 shows a housing for casing the catalytic converter in accordance with an embodiment of the invention.
Figure 4 shows a housing for casing a catalytic converter adapted to an exhaust pipe of a vehicle in accordance with an embodiment of the invention.
Figure 5 shows front view of a motor vehicle, in accordance with an embodiment of the invention.
Figure 6 shows a comparative characteristic curve of time vs temperature in accordance with an embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION
[018] The present invention is directed to a housing for a catalytic converter.
[019] Figure 1 illustrates an exemplary motor vehicle 400, in accordance with an embodiment of the invention. The motor vehicle 400 comprises an Internal Combustion (IC) engine 410 that is vertically disposed. Preferably, the IC engine 410 is a single-cylinder type IC engine. The two-wheeled motor vehicle 400 comprises a front wheel 420, a rear wheel 430, a frame member, a fuel tank 440 and a seat assembly 450 having a front seat 450a and a rear seat 450b. The frame member includes a head pipe 460, a main tube 470, a down tube (not shown), and seat rails (not shown). The head pipe 460 supports a steering shaft (not shown) and two telescopic front suspensions 480 (only one shown) attached to the steering shaft through a lower bracket (not shown). The two telescopic front suspensions 480 support the front wheel 420. The upper portion of the front wheel 420 is covered by a front fender 490 mounted to the lower portion of the telescopic front suspension 480 at the end of the steering shaft. A handlebar 500 is fixed to upper bracket (not shown) and can rotate to both sides. A head light 510, a visor guard (not shown) and instrument cluster (not shown) is arranged on an upper portion of the head pipe 460. The frame member comprises a down tube that may be located in front of the engine 410 and extends slantingly downward from head pipe. The main tube 470 of the frame member is located above the engine 410 and extends rearward from head pipe 460. The engine 410 is mounted at the front to the down tube 460 and a rear of the engine 410 at the rear portion of the main tube 470.
[020] A fuel tank 440 is mounted on the horizontal portion of the main tube 470. Seat rails are joined to main tube 470 and extend rearward to support the seat assembly 450. A rear swing arm 520 is connected to the frame member to swing vertically, and the rear wheel 430 is connected to rear end of the rear swing arm 520. Generally, the rear swing arm 520 is supported by a mono rear suspension 530 or through two suspensions on either side of the motor vehicle. A tail light unit (not shown) is disposed at the end of the motor vehicle 400 and at the rear of the seat assembly 450. A grab rail is also provided on the rear of the seat rails. The rear wheel 430 arranged below the rear seat 450b rotates by the driving force of the engine 410 transmitted through a chain drive (not shown) from the engine 410. A rear fender 540 is disposed above the rear wheel 430.
[021] Further, an exhaust pipe 300 of the vehicle extends vertically downward from the engine 410 up to a point and then extends below the engine 410, longitudinally along the vehicle 400 length before terminating in a muffler 550. The muffler 550 is typically disposed adjoining the rear wheel 430.
[022] As shown in Figure 2, a catalytic converter 200 meant to be adapted to an exhaust pipe 300 of a vehicle extends between an inlet 210 and an outlet 220. The catalytic converter 200 is further defined by an outer surface 230 and an inner surface (not shown). The inlet 210 of the catalytic converter 200 is coupled with effluent receiving portion 300a of an exhaust pipe 300 and outlet 220 of the catalytic converter 200 is coupled with effluent releasing portion 300b of the exhaust pipe 300. Accordingly, as shown in Figure 3, the effluents released from an engine 410 are received inside the catalytic converter 200 from the effluent receiving portion 300a of the exhaust pipe 300 through the inlet 210 of the catalytic converter 200. These effluents are then treated in the catalytic converter 200 and are released into air from the outlet 220 of the catalytic converter 200 through the exhaust releasing portion 300b of the exhaust pipe 300.
[023] In an embodiment of the invention, a first hoop 30 is provided between the inlet 210 of the catalytic converter 200 and the effluent receiving portion 300a of the exhaust pipe 300, and a second hoop 40 is provided between the outlet 220 of the catalytic converter 200 and effluent releasing portion 300b of the exhaust pipe 300.
[024] As shown in Figures 2 and 3, the first hoop 30 extends between a first end 30a and a second end 30b. The first end 30a is adapted on the effluent receiving portion 300a of the exhaust pipe 300. In order to be superposed over the effluent receiving portion 300a of the exhaust pipe 300, the first end 30a of the first hoop 30 has a circular cross section. Further, the second end 30b is adapted on the inlet 210 of the catalytic converter 200, thereby joining the catalytic converter 200 to the effluent receiving portion 300a of the exhaust pipe 300. The first end 30a of the first hoop 30 is joined to the effluent receiving portion 300a of the exhaust pipe 300 and the second end 30b of the first hoop 30 is joined to the inlet 210 of the catalytic converter 200 by metal joining techniques like welding, brazing, soldering, riveting etc., more specifically, welding.
[025] As shown in Figures 2 and 3, the second hoop 40 extends between a first end 40a and a second end 40b. The first end 40a of the second hoop 40 is adapted on the outlet 220 of the catalytic converter 200, thereby joining the catalytic converter 200 to the exhaust pipe 300. The second end 40b is adapted on the effluent releasing portion 300b of the exhaust pipe 300. In order to be superposed over the effluent releasing portion 300b of the exhaust pipe 300, the second end 40b has a circular cross section. The first end 40a of the second hoop 40 is joined to the outlet 220 of the catalytic converter 200 and second end 40b of the second hoop 40 is joined to the effluent releasing portion 300b of the exhaust pipe 300 by metal joining techniques known in the art like welding, brazing, soldering, riveting etc., more specifically, welding.
[026] As shown in Figures 3 and 4, a housing 100 is provided to encase the catalytic converter 200. In this regard, as shown in Figure 1, the housing 100 extends between a first end 110 and a second end 120. Further, the housing 100 is defined by an outer surface 130 and an inner surface (not shown). While placing the housing 100 on the catalytic converter 200, the first end 110 of the housing 100 is positioned adjacent to inlet 210 of the catalytic converter 200 and the second end 120 of the housing 100 is positioned adjacent to outlet 220 of the catalytic converter 200. Once positioned, the first end 110 and the second end 120 of the housing 100 are sealed adjacent to the inlet 210 and outlet 220 respectively of the catalytic converter 200 such that the catalytic converter 200 is encased by the housing 100 and an airtight space 50 is created between the outer surface 230 of the catalytic converter 200 and the inner surface of the housing 100. In an embodiment of the invention, the housing 100 has a cylindrical profile thereby circumferentially encasing the catalytic converter 200. It may be noted that sealing of the first end 110 and the second end 120 is done such that inner surface of the housing 100 does not touch the outer surface 230 of the catalytic converter 200. Also, the first end 110 and the second end 120 of the housing 100 are sealed by permanent metal joining processes known in the art like welding, brazing, soldering, riveting etc. more specifically, welding.
[027] In an embodiment of the invention, the airtight space 50 between the inner surface of the housing 100 and the outer surface 230 of the catalytic converter 200 is filled with air or an insulating material like glass wool. In another embodiment of the invention, the airtight space 50 is coupled with a vacuum creating device thereby creating a vacuum inside the airtight space 50. Accordingly, the air or the insulating material or the vacuum inside the airtight space reduces the rate of heat loss from the catalytic converter 200.
[028] In an embodiment of the invention, as shown in Figures 3 and 4, the first end 110 of the housing 100 is adapted and sealed on the first hoop 30, and the second end 120 of the housing 100 is adapted and sealed on the second hoop 40 thereby circumferentially encasing the catalytic converter 200. In this regard, the sealing is achieved by metal joining techniques like welding, brazing, soldering, riveting etc., more specifically, welding.
[029] In and embodiment of the present invention, the housing 100, the first hoop 30, and the second hoop 40 are made of stainless steel or mild steel.
[030] Referring to Figure 5 which is a front view of the motor vehicle 400, in accordance with an embodiment of the present invention. As seen in Figure 5, the front fender 490 circumferentially overlaps the front wheel 420 and the engine 410 is disposed behind the front wheel 420. The exhaust pipe 300 extends from the engine 410 to a tail end of the motor vehicle 400. The vehicle 400 has a longitudinal axis which extends from center of the front wheel 420 to center of the rear wheel 430.
[031] In an embodiment of the present invention, the exhaust pipe 300 extends frontwards from the engine 410. The exhaust pipe 300 then turns obliquely downwards to the effluent receiving portion 300a. Subsequently, the exhaust pipe 300 extends rearwards from the effluent releasing portion 300b towards a rear wheel 430 along the longitudinal axis of the motor vehicle 400.
[032] Further, as seen in the figure, and as stated herein above, the housing 100 of the present invention encasing the catalytic converter 200, is disposed between the exhaust receiving portion 300a and the exhaust releasing portion 300b of the exhaust pipe 300. Accordingly, the catalytic converter 200 is obliquely disposed. Further, the catalytic converter 200 along with the housing 100 is disposed offset from the longitudinal axis of the vehicle 400.
[033] Figure 6 is a comparative characteristic curve showing time taken by a catalytic converter to reach a lightoff temperature represented by central line A. The lightoff temperature is typically the temperature at which catalysts in a catalytic converter are activated. Further, the graph shows the time required to reach lightoff temperatures by a catalytic converter in three conditions represented by lines B, C and D. Thus, line D represents a condition when there is no housing provided on the catalytic converter 200. Line C represents a condition when there is a housing provided on the catalytic converter 200, but there is no airtight gap between the housing 100 and the catalytic converter 200. Line B represents a condition when there is a housing 100 provided on the catalytic converter 200 with an airtight space 50 between the outer surface 230 of the catalytic converter 200 and the inner surface of the housing 100 in accordance with the present invention.
[034] Thus, as shown in Figure 6, the airtight arrangement provided by the housing 100 advantageously causes the catalytic converter 200 to reach its lightoff time faster as compared to situations when no housing was provided for the catalytic converter or when there was a housing provided, but there was no airtight space provided between the housing and the catalytic converter. In other words, due to the housing of the present invention, the catalysts in the catalytic converter 200 get heated to the desired temperature quicker, due to which the catalysts are activated faster in order to begin treating the effluents received from the engine 410.
[035] Furthermore, the airtight space 50 also advantageously reduces heat loss of the catalyst present in the catalytic converters. This causes the catalysts in the catalytic converters to remain in their active temperatures for longer durations and thus treat the effluents for a longer time, thereby releasing substantially more treated effluents into atmosphere.
[036] While the present invention has been described with respect to certain embodiments, it will be apparent to those skilled in the art that various changes and modification may be made without departing from the scope of the invention as defined in the following claims.

, Description:WE CLAIM
1. A housing (100) for a catalytic converter (200) adapted to an exhaust pipe (300), the housing (100) comprises a first end (110) adapted adjacent to an inlet (210) of the catalytic converter (200); and a second end (120) adapted adjacent to an outlet (220) of the catalytic converter (200), wherein the housing (100) extends between the first end (110) and the second end (120) thereby encasing the catalytic converter (200) and creating a space (50) between an outer surface (230) of the catalytic converter (200) and an inner surface of the housing (100).

2. The housing (100) as claimed in claim 1, wherein the housing (100) has a cylindrical profile thereby circumferentially encasing the catalytic converter (200).

3. The housing (100) as claimed in claim 1, wherein the first end (110) of the housing (100) is adapted on a first hoop (30) joining an effluent receiving portion (300a) of the exhaust pipe (300) and the inlet (210) of the catalytic converter (200), and the second end (120) of the housing (100) is adapted on a second hoop (40) joining the outlet (220) of the catalytic converter (220) and an effluent releasing portion (300b) of the exhaust pipe (300).

4. The housing (100) as claimed in claim 2, wherein the first end (110) and the second end (120) of the housing (100) are welded on the first hoop (30) and the second hoop (40) respectively.

5. The housing (100) as claimed in claim 1, wherein the space (50) between the outer surface (230) of the catalytic converter (200) and the inner surface of the housing (100) is filled with air or glass wool.

6. The housing (100) as claimed in claim 1, wherein in the space (50) between the outer surface (230) of the catalytic converter (200) and the inner surface of the housing (100) is formed by vacuum.

7. The housing (100) as claimed in claim 1 is made of stainless steel or mild steel.

8. A motor vehicle (400) having an engine (410) and an exhaust pipe (300) extending frontwards from the engine (410), turning obliquely downwards to an effluent receiving portion (300a) of the exhaust pipe (300) and extending rearwards from an effluent releasing portion (300b) of the exhaust pipe (300) towards a rear wheel (430) along a longitudinal axis of the motor vehicle (400), the motor vehicle (400) comprising: a catalytic converter (200) defined by an outer surface (230) and an inner surface and extending between an inlet (210) and an outlet (220), the inlet (210) being coupled with the effluent receiving portion (300a) and the outlet (220) being coupled with the effluent releasing portion (300b); and a housing (100) extending between a first end (110) and a second end (120) and encasing the catalytic converter (200) having the first end (110) adapted adjacent to the inlet (210) of the catalytic converter (200) and the second end (120) adapted adjacent to the outlet (220) of the catalytic converter (200), and creating a space (50) between the outer surface (230) of the catalytic converter (200) and an inner surface of the housing (100).

9. The motor vehicle (400) as claimed in claim 8, wherein said catalytic converter (200) being obliquely disposed and offset to said longitudinal axis of the motor vehicle (400).

10. The motor vehicle (400) as claimed in claim 8, wherein said engine is substantially vertically disposed with respect to said longitudinal axis of the motor vehicle (400).