DESC:FIELD OF INVENTION
[0001] The present subject matter relates generally to an engine assembly of a vehicle and more particularly to a resonator system for said engine assembly.
BACKGROUND OF INVENTION
[0002] Generally, a vehicle comprises of a frame assembly extending rearwardly from a head tube. The frame assembly acts as a skeleton and a structural member for the vehicle that supports the vehicle loads. A front wheel is connected to a front portion of the frame assembly through one or more front suspension(s). The frame assembly extends towards a rear portion of the vehicle. A rear wheel is connected to a frame assembly through one or more rear suspension(s). The frame assembly comprises of an engine assembly mounted to it. The engine assembly is functionally connected to the rear wheel, which provides forward motion to the vehicle. A muffler assembly is provided at a lateral side of the vehicle mounted to the frame assembly or the vehicle through a mounting bracket. Typically, plurality of panels is mounted to the frame assembly of the vehicle that covers various vehicle parts mounted thereon.
[0003] An engine assembly is mounted to the frame assembly of the vehicle. In a two-wheeled saddle-ride type vehicle, the engine assembly (internal combustion engine) is disposed in a front portion of the vehicle. In case of an internal combustion (IC) engine, there are one or more cylinder bore(s), where combustion happens. The internal combustion (IC) engine, among other components, has a cylinder on top of which a cylinder head is mounted, and receives a reciprocating piston from the bottom. On combustion of the air-fuel mixture, the piston transfers the energy generated during combustion to a crankshaft through a connecting rod thereby driving the crankshaft. In this way, the reciprocatory motion of the piston is converted to rotary motion of the crankshaft. The crankshaft rotation then powers the vehicle.
[0004] The combustion of air fuel mixture inside the cylinder bore results in the reciprocating motion of the piston. During the compression stroke the air fuel mixture burns and is sent out through the exhaust valve. However, the engine performance and emission is adversely affected when some part of the unburnt air fuel mixture leaves through the exhaust port. Continuous efforts are made to solve this issue and enhance the engine performance for the vehicle.
[0005] This is one of the prime reasons why a resonator system comes into action. A resonator is typically used for two basic purposes, one of them being for damping of noise in a muffler unit and the other one being enhancement of the engine performance. Therefore, resonators are attached to engine assemblies to enhance their performance.
[0006] However, the engine assembly is a place which is too clustered and finding a suitable place is tough. There is always a compromise which needs to be made, be it in the size of efficiency of the resonator or the size and efficiency of any other part associated with the engine assembly. Thus, it is an objective of the present subject matter to solve all of the above problems and provide a resonator system for the engine assembly which is easily accommodated and does not compromises with its efficiency or of any other part associated with the engine assembly.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The detailed description of the present subject matter is described with reference to the accompanying figures. Same numbers are used throughout the drawings to reference like features and components.
[0008] Fig. 1 illustrates a right side view of an exemplary two-wheeled vehicle, in accordance with an embodiment of the present subject matter.
[0009] Fig. 2 illustrates a side view of an exhaust emission system connected to an internal combustion engine in accordance with an embodiment of the present subject matter.
[00010] Fig. 3 illustrates a sectional view of the exhaust pipe in accordance with an embodiment of the present subject matter.
[00011] Fig. 4 illustrates an enlarged view of an intermediate member in accordance with an embodiment of the present subject matter.
[00012] Fig. 5 illustrates a perspective view of an exhaust pipe in accordance with an embodiment of the present subject matter.
[00013] Fig. 6 illustrates an enlarged view of an end of the exhaust pipe in accordance with an embodiment of the present subject matter.
DETALIED DESCRIPTION
[00014] Typically, a motor vehicle is operated through an engine assembly mounted to the frame assembly in a front portion and a fuel tank disposed above the engine assembly. Conventionally, internal combustion engine assembly includes a crankcase, a cylinder block coupled to the crankcase, and a cylinder head mounted on the upper part of the cylinder block. Air-fuel mixture is supplied to the engine assembly by means of a carburetor. Thereafter combustion of the air-fuel mixture takes place so that a piston disposed in the engine assembly is set into motion. The piston is operated in a linear motion, after which said liner motion is converted to a rotational motion, wherein said rotational motion is transferred to the rear wheel finally resulting into motion of the vehicle. This mechanism also results in generation of power and torque by the engine assembly.
[00015] Conventionally, internal combustion engine assembly includes a crankcase, a cylinder block coupled to the crankcase, and a cylinder head mounted on the upper part of the cylinder block. A reciprocating piston that is slidably fitted in the cylinder block is connected via a connecting rod to a crankshaft. The crankshaft that is rotatably supported by the crankcase includes a crankshaft inner diameter and a crankshaft web outer diameter on left hand (LH) side and right side (RH) side of the centrally disposed connecting rod. Generally, the LH and RH crankshaft drives a plurality of gears to operate one or more systems of the internal combustion engine.
[00016] The carburetor sends air fuel mixture for combustion process. During the expansion stroke of the piston the mixture comes in through an inlet valve. Whereas during the compression stroke the exhaust valve opens to send the remaining exhaust. But sometimes it happens that a part of unburnt mixture also leaves through the exhaust valve which affects the engine performance. Generally, a resonator system is applied to solve this problem and enhance the engine performance.
[00017] Conventionally the resonator system is generally adopted using the mass and spring principle of Helmholtz resonance. In order to improve the engine performance, the resonator system is used in such a way that a certain amount of backpressure is created to keep the exhaust valve closed for a longer period so that sufficient time is there for complete combustion of the air-fuel mixture. In most of the prior arts the resonator system is fitted below the engine assembly or the exhaust pipe.
[00018] However, such known adaptation of the resonator system faces few challenges. Due to the location of the resonator system explained above the vehicle faces a problem of decreased ground clearance. The system is prone to hitting the ground in a running condition of the vehicle and in some cases breaking too. This also poses a challenge to the safety of the vehicle. Manufacturing, setting up and maintenance of an extra new part are additional challenges. The increased cost and weight of the system are some of the other problems which the known state of art faces.
[00019] The present subject matter overcomes the above stated problems of the installation of the resonator system in the prior art. One of the objectives of the present subject matter is to provide a resonator system for an engine assembly to enhance its performance. Another objective of the present subject matter is to provide a resonator system which eliminates the need of an extra added part and serves as an integral element. In an embodiment yet another objective of the present subject matter is to provide such a system which does not reduces or comprises with the ground clearance of the vehicle. One of the other objectives of the present subject matter is to provide a resonator system which helps in reduction of the manufacturing and implementation cost, and does not affects the weight of the engine assembly.
[00020] In an embodiment in accordance with the present subject matter, a two-wheeled vehicle employed with a resonator system for the engine assembly is provided. The resonator system is provided in such a way that there is no need for an extra part or element to serve the purpose.
[00021] In an embodiment, an exhaust pipe extends downwardly from an exhaust port in a rearward fashion. The exhaust pipe comprises of an outer pipe concentrically disposed over an inner pipe. The inner pipe and outer pipe are held together with the help of an intermediate member disposed between them. The arrangement of outer pipe and inner pipe is put together in such a fashion that a substantial gap is created between them. The inner pipe is directly connected to the exhaust port and it is through the inner pipe that the exhaust travels. The outer pipe is formed over the inner with a substantial gap between them. The gap between the outer surface of the inner pipe and the inner surface of the outer pipe, combined with the intermediate member act as the resonator system provided to enhance the engine performance. The ring space is halved purposely to serve a dual purpose, first of holding the pipe arrangement and secondly to serve as a neck for the resonator system.
[00022] In an embodiment, the exhaust leaves the engine assembly and enters the inner pipe through the exhaust port. The exhaust travels through the inner pipe and reaches its end but some enters the muffler assembly to react with the catalytic converter, whereas some of them enter the gap created between the inner pipe and the outer pipe. This is because there is a pressure difference in the gap which needs to filled to maintain equilibrium. At a certain throttle valve opening range, resonance of the exhaust gas occurs in such a fashion that the gap between the outer pipe and inner pipe acts as a spring and the length of the neck, i.e. the intermediate member acts like a mass of the spring mass system. Generally, the throttle valve opening range varies between 30%-70% when resonance process for the exhaust gas is initiated. Therefore, at resonance maximum amplitude of oscillation occurs resulting in creation of a higher back pressure of the exhaust gas which helps in closing the exhaust valve for a longer time resulting in complete burning of the air-fuel mixture.
[00023] Thus, the present subject matter increases the performance of the engine assembly without hampering the ground clearance of the vehicle. It eliminates the need of an extra part or element which needs to be added to enhance the performance. The present subject matter also serves its purpose without increasing the weight of the system. In addition to all other advantages it also reduces the manufacturing cost and implementation cost as compared to the previous used resonator systems.
[00024] The aforesaid and other advantages of the present subject matter would be described in greater detail in conjunction with the figures in the following description.
[00025] Arrows provided in the top right corner of each figure depicts direction with respect to the vehicle, wherein an arrow F denotes front direction, an arrow R indicated R direction, an arrow Up denotes upward direction, an arrow Dw denoted downward direction, an arrow Rh denotes right side, an arrow Lh denoted left side, as and where applicable.
[00026] Fig. 1 illustrates a right side view of an exemplary two-wheeled vehicle (10), in accordance with an embodiment of the present subject matter. However, the present subject matter can be used for multi-wheeled vehicles comprising of two-heeled and three-wheeled vehicles. Henceforth, for the purposes of this application the multi-wheeled vehicle may be referred as a two-wheeled vehicle or a vehicle. The vehicle (10) includes a frame assembly (not shown) that extends from a head tube (not shown), which is disposed in the front portion of the vehicle (10). The frame assembly includes a mainframe (not shown) comprising a main tube extending rearward from a rear portion of the head tube and a down tube (not shown) that extends rearwardly downward from the head tube. The frame assembly may further comprise a sub-frame formed by a pair of rear tubes (not shown) that extend obliquely rearward from the main frame. An internal combustion engine (5) is supported by the main frame of the frame assembly. The internal combustion engine (5) acts as the power unit of the vehicle (10), wherein the power unit may also include a traction/electrical motor (not shown). A front portion of a swing arm assembly is swingably connected to the main frame of the frame assembly and rear portion of the swing arm assembly rotatably supports a rear wheel (3). The rear wheel (3) is functionally coupled to the internal combustion engine (5) through a transmission system. An exhaust emission system (15) extending in a rearward direction along the vehicle (10) length is attached to the internal combustion engine (5) to oxidize the exhaust being generated by it. A rear fender (4) disposed upwardly of the rear wheel (3) covers at least a portion of the rear wheel (3). Further, the swing arm assembly is coupled to the frame assembly through one or more rear suspension(s). A pair of front forks (7) supports a front wheel (6) and is steerably supported by the head pipe. A handlebar assembly (1) is connected to an upper portion of the pair of front fork (7). Further, a front fender assembly (11) covers at least a portion of the front wheel (6) and the front fender assembly (11) is mounted to the front forks (7).
[00027] A fuel tank (9) is mounted to the main tube of the frame assembly and disposed rearwardly of the handlebar assembly (1). A seat assembly (2) is disposed rearwardly of the fuel tank assembly (1) and supported by the pair of rear tubes. Further, the vehicle (10) comprises a visor assembly (12) that is disposed forwardly over the headlamp (8). A tail cover assembly (13) is disposed rearwardly of the side panel assembly (not shown) and extends along the pair of rear tubes thereby covering at least a portion of the pair of rear tubes. The tail cover assembly (13) extends towards a rear portion of the frame assembly and the tail cover assembly (13) is adapted to accommodate a pillion handle (14) attached to its side. The present invention can be used for a two-wheeled as well as three-wheeled vehicle. Hence the term two-wheeled vehicle is interchangeably used as vehicle and multi-wheeled vehicle which includes both, a two-wheeled and three-wheeled vehicle.
[00028] Fig. 2 illustrates a side view of the exhaust emission system (15) attached to the internal combustion engine (5) in accordance with an embodiment of the present subject matter. In an embodiment, the internal combustion engine (5) comprises of a cylinder head (21) which allows the combustion to occur. In addition to it, the exhaust emission system (15) comprises of an exhaust pipe (22) connected to the cylinder head (21) of the internal combustion engine (5). The exhaust pipe (22) extends in a downward and rearward direction with the other end attached to a muffler assembly (23). In an embodiment, the muffler assembly (23) is provided for oxidation of the exhaust and dampening the sound being generated by the internal combustion engine (5).
[00029] Fig. 3 illustrates a sectional view of the exhaust pipe (22) in accordance with an embodiment of the present subject matter. In an embodiment, the exhaust pipe (22) extends in a downward and rearward fashion from the internal combustion engine (5). As per an embodiment of the present subject matter, the exhaust pipe (22) comprises of a plurality of pipes, an inner pipe (31) and an outer pipe (32), wherein the outer pipe (32) is concentrically disposed over the inner pipe (31) to form the exhaust pipe (22). In an embodiment, the outer pipe (32) is disposed over the inner pipe (31), wherein the outer pipe (32) is attached to the inner pipe (31) by welding an intermediate member (33) between them to hold the whole arrangement together. In furtherance to it, a catalytic converter (34) is attached on the other end of the exhaust pipe (22), such that the exhaust travelling through the exhaust pipe (22) hits the catalytic converter (34) for oxidation reaction.
[00030] Fig. 4 illustrates an enlarged view of the intermediate member (33) used in the exhaust pipe (22), in accordance with an embodiment of the present subject matter. In an embodiment, the intermediate member (33) is substantially semicircular in shape, designed to hold the inner pipe (31) and outer pipe together. In addition to it, the intermediate member (33) also acts as a neck used in the mass spring principle of a resonator system.
[00031] Fig. 5 illustrates a perspective view of the exhaust pipe (22) in accordance with an embodiment of the present subject matter. In an embodiment, the exhaust pipe (22) extends from the cylinder head (21) of the internal combustion engine (5) and gets connected to the muffler assembly (23) of the exhaust emission system (15) at the other end. As per an embodiment of the present subject matter, the exhaust pipe (22) comprises of a plurality of pipes (31, 32) attached together to form said exhaust pipe (22). The exhaust pipe (22) comprises of an inner pipe (31) and an outer pipe (32) wherein the pipe arrangement is held together by the intermediate member (33). As per the present subject matter, the outer pipe (32) is concentrically disposed over the inner pipe (31) such that a substantial gap (G) is present between the whole arrangement, i.e. the inner surface of the outer pipe (32) and outer surface of inner pipe (31). In an embodiment, the outer pipe (32) runs over the inner pipe (31) throughout its length, and both of them are concentrically disposed. According to an aspect of the present subject matter, the gap (G) between the inner pipe (31) and the outer pipe (32) combined with the intermediate member (33) serves as the resonator system used for enhancement of the internal combustion engine (5) performance.
[00032] Fig. 6 illustrates an enlarged view of an end of the exhaust pipe (22) in accordance with an embodiment of the present subject matter. In an embodiment, the exhaust pipe (22) is arranged in such a way that the outer pipe (32) is disposed over the inner pipe (31). Both the pipes are concentrically disposed and the outer pipe (32) extends over the length of the inner pipe (31) with a substantial gap (G) formed between them. The inner pipe (31) and outer pipe (32) are held together by the at least one intermediate member (33) welded between them. The intermediate member (33) substantially covers half of the gap (G) between the inner pipe (31) and outer pipe (32). However, the intermediate member (33) holds the inner pipe (31) and outer pipe (32) and covers the gap (G) only near the end connected to the muffler assembly (23), and not over the complete length of the exhaust pipe (22). Moreover, the intermediate member (33) also acts as the neck required for the resonance to occur. As per another embodiment of the present invention, the intermediate member (33) may have different forms like perforated openings on the arc or complete circular member, different width etc. Also, as per another embodiment, a combination of more than one intermediate member may be disposed along the circumference in form of arc. As per another embodiment, a plurality of intermediate members may be tuned to be disposed along the length of the exhaust tube to achieve the desired resonator effect for the engine.
[00033] As per an embodiment of the present subject matter, the exhaust travels from the internal combustion engine (5) through the inner pipe (31) of the exhaust pipe (31). After travelling it hits the catalytic converter (34) disposed at the other end of the exhaust pipe (22). However, not all the exhaust traveling through the inner pipe (31) hits the catalytic converter (34) and enters the muffler assembly (23). Some of it rushes in the gap (G) because of the pressure difference present there, thus the exhaust rushes in the gap (G) to maintain the equilibrium. A substantial amount of exhaust fills the gap (G) over the period of time. As per an embodiment of the present subject matter, the resonator system is arranged such that at a throttle opening range of 30%-70% the resonance of the gases occurs and the gap (G) between the inner pipe (31) and outer pipe (32) starts acting as the mass, and the neck, i.e. the intermediate member (22) starts acting as the spring. Hence, all the elements of the mass spring principle are present enabling resonance of the exhaust to occur. Therefore, during this time of resonance the maximum amplitude of oscillation occurs resulting in a higher back pressure of the exhaust gas forcing the exhaust valve to be closed for a longer duration of time. Hence, a longer time is presented for the air-fuel mixture to burn properly resulting in a better performance of the internal combustion engine (5).
[00034] Thus, the present subject matter presents an exhaust pipe (22) comprising of an inner pipe (31) and an outer pipe (32), wherein the outer pipe (32) and inner pipe (31) combined together to form said exhaust pipe (22). The outer pipe (32) is disposed over the inner pipe (31) and runs across its length, and wherein both the pipes (31, 32) are concentrically disposed. An intermediate member (33) is provided to hold the inner pipe (31) and outer pipe (32), and also covers a gap (G) formed between the outer pipe (32) and inner pipe (41).
[00035] It is to be understood that the aspects of the embodiments are not necessarily limited to the features described herein. Many modifications and variations of the present subject matter are possible in the light of above disclosure. Therefore, within the scope of claims of the present subject matter, the present disclosure may be practiced other than as specifically described.
,CLAIMS:We Claim:
1. A multi-wheeled vehicle (10) comprising:
an internal combustion engine (5) to provide required power to said vehicle (10); and
an exhaust emission system (15) comprising an exhaust pipe (22) extending in a downward rearward fashion from said internal combustion engine (5) to get attached to a muffler assembly (23), wherein said exhaust pipe (22) comprises a plurality of pipes (31, 32) disposed over each other with at least one intermediate member (33) provided therein to hold said plurality of pipes (31, 32).
2. The multi-wheeled vehicle (10) as claimed in clam 1, wherein said plurality of pipes (31, 32) comprises an outer pipe (32) concentrically disposed over said inner pipe (31) with a substantially circular shaped gap (G) formed between them.
3. The multi-wheeled vehicle (10) as claimed in claim 1 or claim 2, wherein said inner pipe (31) extends in a downward rearward fashion from said internal combustion engine (5) carrying exhaust formed therein to terminate at said muffler unit (23).
4. The multi-wheeled vehicle (10) as claimed in claim 1 or claim 2, wherein said outer pipe (32) extends over entire length of said inner pipe (31) to terminate at said muffler unit (23).
5. The multi-wheeled vehicle (10) as claimed in claim 1, wherein said intermediate member (33) holding said plurality of pipes (31, 32) is substantially semicircular shaped.
6. The multi-wheeled vehicle (10) as claimed in claim 1, wherein said intermediate member (33) is welded between said plurality of pipes (31, 32) at an end attached to said muffler assembly (23).
7. The multi-wheeled vehicle (10) as claimed in claim 1, wherein said intermediate member (33) substantially blocks half of area of said gap (G) formed near said muffler assembly (23) end.
8. A method for reducing NOx being generated by an internal combustion engine (5), said method comprising:
arranging an outer pipe (32) over an inner pipe (31) allowing a substantial gap (G) to be formed between them, wherein said outer pipe (31) and said inner pipe (31) is attached to said internal combustion engine (5);
flowing of exhaust from said internal combustion engine (5) through an inner pipe (31) attached thereto;
receiving a flow of exhaust in said gap (G) after being released from said inner pipe (31).
9. The method as claimed in claim 8, wherein said entering of exhaust in said gap (G) after being released from said inner pipe (31) resonates at 30%-70% of throttle opening.
10. A resonator system for a multi-wheeled vehicle (10), wherein said resonator system comprises:
an exhaust pipe comprising an outer pipe (32) concentrically disposed over said inner pipe (31) resulting in formation of a gap (G) between them, wherein said inner pipe (31) and said outer pipe (32) are held through at least one intermediate member (33) provided therein.