Field of Invention

[0001] The present invention relates to an exhaust gas heat recovery muffler and more particularly to a muffler that enables heat exchange from exhaust gases to a heat exchange chamber and further transfers the said heat to the intake system thereby enhancing engine efficiency and
performance.

Description of Prior Art

[0002] It is an acknowledged fact that most modern scooters and motorcycles are equipped with reciprocating engines. A typical motorcycle includes a front wheel and a rear wheel suspended towards the front and rear end of the frame respectively. A power unit is mounted on the frame to
generate power required to propel the motorcycle. The power unit converts chemical energy of the fuel into heat energy, which is further converted into mechanical motion of the vehicle. In Power unit, the burning of air-fuel mixture takes place inside an engine cylinder. The enormous pressure and heat generated by this combustion forces a piston residing in cylinder block to reciprocate and rotate a crankshaft connected to it by a connecting rod.

[0003] As this combustion cycle transpires hot gases are produced in the cylinder block, which are expelled out to the atmosphere through the exhaust system. The exhaust gases that are discharged from the internal combustion engine have a high temperature, typically about 850°F to 1200°F.

The heat inherent in these exhaust gases is generally wasted. The same heat could be utilized for heating the air intake of the power unit to enhance the efficiency of the motorcycle.

[0004] One such arrangement in which heat of exhaust gases have been used for improving vehicle efficiency has been disclosed in US Patent No. 7063134 titled 'Combined muffler/heat exchanger". The disclosed invention includes a housing, a flow regulator, a fluid transport member and an acoustic regulator. The housing includes a cylindrical shell, an input header located at an input end, and an output header located at an output end. The cylindrical shell defines a heat transfer chamber and an acoustic attenuation chamber separated by a partition. During operation, a constant stream of exhaust from an internal combustion engine flows through the combined muffler and heat exchanger apparatus from its input end to its output end. Contemporaneously, a constant stream of heat recovery fluid flows through the fluid transport member from the inlet portion to the outlet portion. The exhaust stream heats the fluid transport member and the heat recovery fluid carried therein. The heat recovery fluid reaches the outlet portion of the fluid transport member and is carried to the vehicle climate control system. The heat recovery fluid can then be used to provide heat to a vehicle cabin and for air preheating.

[0005] The above described prior art arrangement consumes much space and lacks economical configuration and cannot be used in small vehicles such as two wheelers and three wheelers. Further the fluid transport member is sufficiently large to burn off the air filter due to excess temperature rise and hence results in poor engine performance. It would therefore be very desirable to have an exhaust gas heat recovery muffler, which is simple in structure, is suitable for use in small vehicles such as two wheelers and three wheelers and that which optimises the overall efficiency of the vehicle.

Summary of Invention

[0006] The present invention has been conceived in view of the foregoing drawbacks in the prior art and it is the primary objective of the present invention to provide an exhaust gas heat recovery muffler, which enables transfer of heat from exhaust gases to the engine intake system. It is another objective of the present invention to provide an exhaust gas heat recovery muffler that is simple in structure and is suitable for use in small vehicles such as two wheelers and three wheelers.

[0007] The exhaust gas recovery muffler as per the present invention is characterized by a heat exchange pipe extending axially through a muffler casing. The muffler casing has an inlet at its downstream end and an outlet at its upstream end. One end of the heat exchange pipe protrudes outside through the inlet and draws in outside air. The other end extends through the outlet and is connected to an intake system of an internal combustion engine. Air drawn from outside is heated during its passage through the muffler casing. The muffler casing acts as a heat exchange chamber for heat exchange between the hot exhaust gases and the outside air drawn inside by the heat exchange pipe. Supply of heated air to the intake system and subsequently to the engine substantially improves engine efficiency and performance and reduces noise.

[0008] These and other features, aspects, and advantages of the present invention will be better understood with reference to the following description, the appended claims and the accompanying drawings. This summary is not intended to limit the scope of the claimed subject matter.

Brief Description of Drawings

[0009] The above and other features, aspects, and advantages of the present invention are further illustrated by the accompanying drawings. The drawings are given by way of illustration only and are not limitative of the present invention. A brief description of the drawings is as follows:

Fig. 1 illustrates a side view of a conventional two-wheeled vehicle.

Fig. 2 is a schematic drawing of the exhaust gas heat recovery muffler as per the present invention.

Fig. 3 illustrates the interior of the exhaust gas heat recovery muffler as per the present invention.

Detailed Description of Invention

[0010] The present invention is hereinafter described with reference to the accompanying drawings. It is to be noted that like reference numerals designate corresponding or identical elements throughout the various drawings. The terms front and rear, and left and right as used indicate the front and rear and the left and right directions when viewed by a rider seated on the vehicle seat.

[0011] Fig. 1 illustrates a conventional motorcycle 111 including a front wheel 121, a rear wheel 131, an internal combustion engine 141, and a body frame 151 interconnecting the front wheel 121 and the rear wheel 131. The front wheel 121 is mounted to a front fork 181 which in turn is mounted to the body frame 151 The motorcycle also includes a steering assembly 161 coupled to the body frame 151. The steering assembly 161 is pivotable about a steering axis and includes a handlebar 171 for imparting such pivotal motion to the steering assembly 161. The internal combustion engine 141 has an exhaust port to which a muffler 100 is connected through an exhaust pipe 101. Those skilled in the art will appreciate that the vehicle shown in Fig. 1 is a single example and the present invention is not limited to application to any one particular bike size, type, or manufacturer. It can also be appreciated that although the exhaust system presented herein is preferred for smaller displacement engines, such as those powering motorcycles, all-terrain vehicles, scooters, and three wheeled vehicles, the system is adaptable to all other vehicles unless not restricted.

[0012] Fig. 2 is a schematic layout of the exhaust gas heat recovery muffler as per the present invention. Fig. 2 demonstrates the present invention incorporated within the muffler 100 and further connected to an intake system 240. The intake system 240 is connected to the internal combustion engine 141 through a carburetor 290. The present invention comprises a muffler casing 220. The muffler casing 220 has an inlet 210 at its downstream end 218 and an outlet 230 at its upstream end 219. The present invention is characterized by a heat exchange pipe 200. The heat exchange pipe 200 extends axially through the muffler casing 220. One end of the heat exchange pipe 200 protrudes outside the muffler 100 through the inlet 210 and draws in outside air. The other end of the heat exchange pipe 200 extends outside through the outlet 230 and is connected to the intake system 240. Air drawn from outside by the heat exchange pipe 200 is heated due to exchange of heat from the hot exhaust gases. The muffler casing 200 acts as a heat exchange chamber for the heat exchange pipe 200. The heated air is then introduced to the intake system 240 through the other end of the heat exchange pipe 200. The intake system 240 is connected to the internal combustion engine 141 through a carburetor 290. The introduction of heated air to the intake system 240 substantially improves engine performance and efficiency and also reduces noise.

[0013] Fig. 3 illustrates the interior of the exhaust gas heat recovery muffler as per the present invention.

As aforementioned, outside air enters heat exchange pipe 200 through the inlet 210 and passes through the muffler casing 220, which acts as a heat exchange chamber for the heat exchange pipe 200. Muffler casing 220 is equipped with a plurality of partition plates 221, 222 & 223 for dividing an internal space of the muffler casing 220 into a plurality of compartments, which serves as a structural support to the present invention and enhances heat exchange within the muffler casing 220. The heat exchange pipe 200 extends axially through the muffler casing 220 by way of through holes formed on the partition plates 221, 222 & 223.

[0014] The foregoing description is a specific embodiment of the present invention and has been described for the purpose of illustration only. Persons skilled in the art may practice numerous alterations and modifications of the present invention without departing from its spirit and scope. It is intended that all such modifications and alterations be included insofar as they come within the scope of the invention as claimed or the equivalents thereof.

We Claim:

1. A muffler 100 comprising:

a muffler casing 220 having an upstream end 219 and a downstream end 218, said muffler casing further comprising an inlet 210 at the downstream end 218 and an outlet 230 at the upstream end 219; and characterized by a heat exchange pipe 200 extending axially through the muffler casing 220, said heat exchange pipe 200 having its one end protruding outside the muffler 100 through the inlet 210 and an other end extending outside the muffler 100 through the outlet 230.

2. The muffler as claimed in claim 1, wherein the muffler casing 220 further comprises a plurality of partition plates 221,222& 223,said heat exchange pipe 200 extends axially through the muffler casing 220 by way of through holes formed on the partition plates 221,222& 223.

3. A two wheeled automotive vehicle comprising: a body frame 151;

a front fork 181 and a handlebar 171 mounted for rotation on the body frame 151;

a front wheel 121 mounted to the front fork 181;

a rear wheel 131 mounted to the body frame 151;

an internal combustion engine 141 mounted to the body frame, said internal combustion engine 141 provided with an exhaust port;

an intake system 240 connected to the internal combustion engine 141;and

a muffler 100 connected to the exhaust gas port through an exhaust pipe 101, said muffler 100 further comprising a muffler casing 220 having an upstream end 219 and a downstream end 218, said muffler casing 220 having an inlet 210 at the downstream end 218 and an outlet 230 at the upstream end 219, said muffler 100 characterized by a heat exchange pipe 200 extending axially through the muffler casing 220, said heat exchange pipe 200 having its one end protruding outside the muffler 100 through the inlet 210 and an other end extending through the outlet 230 and connected to the intake system 240.

4. The two-wheeled automotive vehicle as claimed in claim 3, wherein the muffler casing 220 further comprises a plurality of partition plates 221, 222 & 223, said heat exchange pipe 200 extends axially through the muffler casing 220 by way of through holes formed on the partition plates 221, 222 & 223.

5. The two-wheeled automotive vehicle as claimed in claim 3, wherein the intake system 240 is connected to the internal combustion engine through a carburetor 290.

6. The muffler as herein above described in the specification and illustrated in the accompanying drawings.