Exhaust system for a vehicle

Field of the invention

The present invention relates to "Vehicle exhaust system" and more particularly to prevent internal paint accumulation and improve engine performance.

Relevant prior art

Exhaust system in vehicles are assembled with an exhaust system for achieving desired performance characteristics of an engine, reduce noise from the engine and for dispensing gases coming out from the exhaust port to the atmosphere. An exhaust system, which at one end is connected to the exhaust port of the engine and at other end, is at rear of the vehicle. Typically the exhaust system comprises of an exhaust pipe, an expansion chamber and a heat shield. This exhaust pipe either may of a single or multiple conduit structure. Optimally, these exhaust systems are designed to be relatively lightweight, and to provide a low profile for ease of mounting upon and use with motorcycles.

Generally the exhaust gases are subjected to after burn devices such as catalytic converters for reducing the emission caused due to unburnt gases. Due to the burning of the gases as they pass through the after burn devices, the temperature of the inner pipe increase immensely and becomes blue in colour. The exhaust gases also have a part of moisture in it. After cooling of the exhaust pipe, moisture tends to corrode the pipe.

As a result of the above problem, internal painting of the inside pipe is done to protect the muffler from rusting due to the moisture condensation. However, once the painting is done, the residue paint is drained out. But because of the internal construction of the main exhaust pipe that has perforations at the end and a cup shaped cap, paint tends to accumulate at that portion. Because of the accumulation, the paint forms a lump that tends to corrode the system faster. As a result of this, the longevity of the exhaust system is reduced. Moreover, it also affects the engine performance owing to lesser expansion space as well as uneven internal construction.

Hence the main objective of the present invention is to provide an exhaust system that overcomes the present lacunae in the prior art and provides an arrangement that facilitates draining of the internal paint and improves engine performance.

Brief description of the invention

In accordance with one of the embodiments of the present invention, an exhaust system for a motorcycle having a four-stroke engine is provided which comprises of an exhaust pipe and an expansion chamber. Perforations are introduced in the pipe at various suitable places. An end cap closes the end of the said exhaust pipe. The said end cap blocks the exhaust gases and forces them out through the said perforations.

The exhaust gases that come out of the engine utilize these perforations and expand within the annular gap between pipe and muffler escape to the expansion chamber. As a result, the torque performance of the engine increases since tliere is low backpressure on the engine from the expanding gases.

Brief description of the drawings

Figure 1 illustrates side view of a motorcycle according to the present invention

Figure 2 illustrates the exhaust system according to the present invention

Figure 3 and 4 illustrate the exhaust pipe according to the present invention

Detailed description of the invention

A selected illustrative embodiment of the present invention will be now described with respect to the accompanying figures 1, 2 and 3. A motorcycle comprises of a frame 101, front fork 102 attached to a pivot tube 103 of the vehicle frame 101, a front wheel 104 attached to these front forks 102, a handle bar 105 connected to the front forks 102, a fuel tank (not shown in the figure) attached so as to straddle an upper part of the vehicle frame 101, a seat 107 attached to the upper rear portion of the vehicle frame 101, an engine unit 108 attached to the lower front section of the vehicle frame 101, a swing arm 109 attached to a lower rear section of the vehicle frame 101, suspended by a rear shock absorber 110 from the vehicle frame 101 and a rear wheel 111 attached to a rear end of swing arm 109. The intake system of the engine (not shown in the figure) comprises of a carburettor, intake duct and an air cleaner. The exhaust system of the engine 201 comprises of exhaust pipe 202 and a muffler 205.

The motorcycle is also provided with a side cover for covering a side section of the vehicle frame 101, a front fender 113 for covering an upper part of the front wheel 104, and a rear fender 114 for covering an upper part of the rear wheel 111.

An exhaust system 201 for a motorcycle having a four-stroke engine 108 comprises of an exhaust pipe 202 , one end of which is assembled with a flange 203 that is connected to cylinder head of the engine 108 with suitable bolts or* studs and nuts. The other end of the exhaust' pipe 202 is either welded or assembled to an expansion chamber 204.
Exhaust gases from the cylinder head are led to the said exhaust pipe 202 and then to the muffler 205 and then released to the atmosphere. The heat shield 206 guards the rider and pillion from the heat of the exhaust system 201.

In accordance with one of the embodiments of the present invention, an exhaust system 201 for a motorcycle having a four-stroke engine 108 is provided which comprises an exhaust pipe 202 and an expansion chamber 204. Perforations 207 are introduced in the pipe 202 at various suitable places. An end cap 208 closes the end of the said exhaust pipe 202. The said end cap 208 blocks the exhaust gases and forces them out through the said perforations 207.

The exhaust gases that come out of the engine 108 utilize these perforations and expand within the annular gap 209 between pipe 202 and muffler 205 escapes to the expansion chamber 204. As a result, the torque performance of the engine 108 increases since there is low backpressure on the engine 108 from the expanding gases.

In the present arrangement, slots/perforations 207 are provided at the rear end of the exhaust pipe 202 at a portion precinct to the end cap 208. As a result of this arrangement, accumulated paint drains out. As a result of this construction, engine noise performance also improves. It should be understood that the foregoing description is that of a preferred embodiment of the invention and that various changes and modifications may be made without departing from the spirit and scope of the invention, as defined by the appended claims. Further any shape and configuration of the extended surface is possible within the ambit of appended claims.

Claims:

We claim:

1. An exhaust system for a vehicle comprising of an exhaust main pipe having perforations covered by an end cap at its end, a series of baffles, a muffler body, a series muffler pipes, an expansion chamber wherein the a number of slots are provided at the rear end of the exhaust pipe at a portioVi precinct to the end cap.

2. The exhaust system as claimed in claim 1, wherein the number of slots is at least one.

3. A motorcycle having the exhaust system as claimed in claim 1.