Abstract: An exhaust system for a snowmobile includes a muffler housing, the bottom end of the muffler housing including a muffler exhaust outlet configured to emit exhaust. The exhaust system includes a muffler housing cover spaced from the muffler housing to define an airflow channel therebetween, the muffler housing cover forming a bottom opening. The exhaust system also includes a gas combiner at least partially surrounding the muffler exhaust outlet on the bottom end of the muffler housing and extending through the bottom opening of the muffler housing cover. The gas combiner receives air from the airflow channel and the exhaust from the muffler exhaust outlet to emit a combined air-exhaust stream.

Abstract: An exhaust-gas treatment module for an exhaust system of an internal combustion engine has a plurality of elements which follow one another in an exhaust-gas flow direction. The elements include a first mixing path with a first reactant dispensing arrangement in an upstream end region of the first mixing path and with a first mixing channel which is elongate in the direction of a first mixing path longitudinal axis. A first exhaust-gas treatment arrangement follows and is elongate in the direction of a first exhaust-gas treatment arrangement longitudinal axis and has an upstream end region connected to a downstream end region of the first mixing path, a second mixing path with a second reactant dispensing arrangement in an upstream end region which is connected to a downstream end region of the first exhaust-gas treatment arrangement.

Abstract: An intake manifold is provided having a base plate with discharge ports and an elongate pipe section extending along a face of the base plate. The pipe section has a front end with an intake port and progressively narrows at least adjacent a rear end. A first port in the rear end enables back-flushing of the manifold, and a second port in the rear end is angled relative to the base plate and enables insertion of a probe. Fork-lift openings extend between the base plate and the pipe section enabling the manifold to be lifted and positioned with a lift truck. Side ports extend through the pipe section and are angled relative to the base plate and adjacent one of the discharge ports to enable visual inspection of the discharge port. The side ports may include side ports located on both sides of the pipe section.

Abstract: An intake manifold assembly includes an exhaust gas recirculation system and an intake manifold. The exhaust gas recirculation system includes a venturi with a venturi body. The venturi body includes an upstream cylindrical portion, a convergent portion, a downstream cylindrical portion, and a divergent portion. The upstream cylindrical portion is in exhaust gas receiving communication with a cylinder of an internal combustion engine system and configured to receive the exhaust gas from the cylinder. The convergent portion is contiguous with the upstream cylindrical portion and in exhaust gas receiving communication with the upstream cylindrical portion. The downstream cylindrical portion is contiguous with the convergent portion, separated from the upstream cylindrical portion by the convergent portion, and in exhaust gas receiving communication with the convergent portion.

Abstract: An exhaust pipe with a double pipe structure that can reduce generation of a turbulent flow of exhaust gases is provided. In one aspect of the present disclosure, the exhaust pipe includes a double pipe and a retention member. The double pipe includes an inner pipe and an outer pipe. The retention member is disposed in a gap provided between an outer circumferential surface of the inner pipe and an inner circumferential surface of the outer pipe. The retention member is disposed at at least one end of the double pipe. At the end of the double pipe where the retention member is disposed, a radial clearance between the outer circumferential surface of the inner pipe and the inner circumferential surface of the outer pipe at an opening of the inner pipe is smaller than the radial clearance in an arrangement area where the retention member is disposed.

Abstract: A nacelle system is disclosed. In various embodiments, the nacelle system may include a nacelle component; an attachment structure; and a bracket configured to secure the nacelle component to the attachment structure, the bracket comprising a first arm having a first bead structure disposed between a proximal end and a distal end of the bracket.

Abstract: An exhaust device includes a first exhaust pipe, a second exhaust pipe, and a third exhaust pipe. The first exhaust pipe is comprised of a pipe member. The second exhaust pipe and the third exhaust pipe are comprised of a tubular member including a merging tubular portion and a downstream tubular portion. In the merging tubular portion, exhaust gas to be discharged from an exhaust port of the second cylinder and exhaust gas to be discharged from an exhaust port of the third cylinder are merged. The merging tubular portion is comprised of combining a plurality of plate members, at least a part of which is formed by press working. A distal end of the first exhaust pipe is disposed inside the downstream tubular portion. The downstream tubular portion is offset on the side of the first cylinder with respect to a center in a cylinder array direction.

Abstract: An exhaust manifold for an internal combustion piston engine with a row of at least two cylinders inclined from the vertical. The exhaust manifold has plural exhaust stack assemblies and a manifold plenum with an outlet. Each of the plural exhaust stack assemblies comprises a leader pipe and an exhaust connector, with a first end of each leader pipe being joined to a first end of the exhaust connector of the exhaust stack assembly, and a second end of each exhaust connector being joined to the manifold plenum. Each leader pipe is joined to a manifold flange that is adapted for joining to the internal combustion engine to receive exhaust gases from the cylinders of the engine. Each leader pipe is joined in a vertical plane to the manifold flange at a first angle so that the plural exhaust stack assemblies are approximately horizontally oriented when joined to the internal combustion engine, and each leader pipe is joined in a horizontal plane to the manifold flange at a second angle inclined toward the outlet.

Abstract: An exhaust structure for an internal combustion engine has an exhaust pipe having an inner pipe through which exhaust gas of the internal combustion engine circulates, and an outer pipe covering an outer periphery of the inner pipe, and in the exhaust pipe, an inner radiation layer provided on an outer surface of the inner pipe and having a higher emissivity than the inner pipe, an outer radiation layer provided on an inner surface of the outer pipe and having a higher emissivity than the outer pipe, and an intermediate layer proposed between the inner radiation layer and the outer radiation layer, configured to pass infrared radiation therethrough, and having a lower coefficient of thermal conductivity than the inner pipe and the outer pipe are provided.

Abstract: A exhaust gas purifier includes a case having a flat transverse section including a pair of facing short sides and a pair of facing long sides, and configured to house a catalytic converter, and an inlet cone including a conical portion, and configured to connect an outlet of the turbine to an inlet of the case. The conical portion includes an inclined wall inclined from a mainstream of the exhaust gas to increase the transverse section of a path of the exhaust gas. A recess recessed inward is formed in a portion corresponding to each of the long sides of the inclined wall of the conical portion.

Abstract: A decoupler includes a short bellows of ten or fewer convolutions, an internal liner spaced from the bellows internally and a cover spaced radially outward from the bellows providing an air gap both internally and externally of the bellows. The liner has a free-standing downstream end proximate a damper which is captured by a cover, inner damper ring and slide ring. Two decouplers are mounted in series to accommodate angular, axial and lateral displacement when operably connecting two end pipes and one central pipe.

Abstract: An intake manifold provided as an integral one-piece manifold body. The manifold has a base plate with a series of spaced apart discharge ports and an elongate tapered pipe portion formed integrally with the base plate, having an inlet, and having inner tapered walls for directing flow through the manifold body from the inlet through the discharge ports of the base plate.

Abstract: A connector system facilitates the connection of a first tree trunk to a second tree trunk of an artificial tree system. The connector system can prohibit rotation of the first tree trunk relative to the second tree trunk.

Abstract: A fastening device (10) is disclosed for attaching a fluid transport circuit to an element of a structure of an aircraft, with the fluid transport circuit containing two portions (23, 42), each of which is made up of an external tube (22, 44) positioned around an internal tube (21, 43). The fastening device (10) is positioned at a connection (40) between the two portions (23, 42) of the fluid transport circuit, and contains a body (26) with a plate (27) to attach the fastening device (10) to an element (61) of the structure of the aircraft. The body (26) provides at least one sealed connection between the external tubes (22, 44) of the two portions (23, 42) and a support system provides a constant radial clearance between the internal tubes (21, 43) and the external tubes (22, 44) of the two portions (23, 42) of the fluid transport circuit.

Abstract: In a first embodiment, at a time of magnetic pulse welding, a stepped tube profile machining process axially bores a walled tube from an end inward to a transition depth to form a section with a reduced wall thickness and then axially bores the walled tube from the transition depth to a fall off depth, thereby forming a section with a maximized welding wall section. In a second embodiment, also at a time of magnetic pulse welding, a surface angle tube profile machining process axially bores at a surface angle a walled tube from an end to a bore length to form an angular welding wall thickness inward to a maximized wall section. For both embodiments, the bored surfaces are virgin with no pits, oil, residue, or oxidation thereon, thus making the machined walled tubes available for immediate magnetic pulse welding.

Abstract: A motorcycle includes an engine, a first main frame extending in top-to-bottom and front-to-rear directions with respect to the vehicle to support the engine, a first rear frame extending from the first main frame rearwardly with respect to the vehicle and connected with the first main frame in at least two locations, an exhaust pipe that discharges exhaust gases from the engine to the outside, and a silencer attached to a rear portion of the exhaust pipe, at least a portion of the silencer being located below the first rear frame. A rear portion of the silencer is connected with the first rear frame. At least one of a front portion of the silencer and the exhaust pipe is connected with the first main frame below the first rear frame.

Abstract: A motor vehicle in which a de-coupler has a first attachment point to a cab body, a second attachment point to a vertical engine exhaust pipe, and a de-coupler mechanism having at least one ball joint which allows limited vertical and limited horizontal movement of the engine exhaust pipe relative to the cab body.

Abstract: The present invention relates to an exhaust manifold for preventing condensate and gas leakage in an engine, and more particularly, to an exhaust manifold for preventing condensate and gas leakage in an engine, capable of preventing peripheries of the engine from being contaminated by condensate and/or exhaust gas leaking from interiors of a plurality of exhaust manifolds to the outside through connection portions of the exhaust manifolds.

Abstract: A hydraulic excavator includes an engine, a rotating frame, a vehicle body frame, a diesel particulate filtering device, a selective catalytic reduction device and a connecting pipe. The rotating frame supports the engine. The vehicle body frame is provided in a standing manner on the rotating frame, and includes a plurality of column members. The a diesel particulate filtering device and the selective catalytic reduction device process exhaust from the engine, and are supported by the vehicle body frame. The connecting pipe has an extendable bellows part in at least a portion. The connecting pipe connects the engine and the diesel particulate filtering device. The bellows part is located further away from the engine as the bellows part inclines further downward.

Abstract: A motorcycle has a crankcase containing a crank shaft and a balancer shaft, and a cylinder and a cylinder head positioned above the crankcase, and an exhaust pipe extends from the cylinder head. The balancer shaft is positioned in front of the crank shaft, and the crankcase has a balancer shaft housing supporting the balancer shaft thereinside, and has a recessed part depressed rearward in a front end center part of the balancer shaft housing. The balancer shaft has balancer shaft weights apart from each other in one side and in the other side in an axis direction.

Abstract: An exhaust connection coupler and a method for manufacturing a braid cover incorporated therein are provided. The method of manufacturing comprises the steps of providing a tubular sleeve formed of braided wire filaments and forming at least one end of the sleeve into shape using a forming die such that the at least one end of the cover includes a circumferential neck portion having a diameter smaller than the diameter of a body portion of the cover. In the method, the sleeve may be pressed between male and female forming dies in order to create the cover's desired shape, which can include a shoulder extending radially outwardly from the cover's neck portion and meeting the cover's body portion at a corner.

Abstract: An exhaust gas purification device capable of enhancing handling operability such as maintenance of an engine includes two gas purification bodies which purify exhaust gas discharged from the engine, inner cases in which the gas purification bodies are incorporated, and outer cases in which the inner cases are incorporated. The outer cases are arranged side by side in a moving direction of exhaust gas and connected to each other. One of the adjoining inner cases is inserted into the other inner case to form a double-layer structure. A loosely-fitting gap is formed between an inner side surface of the one inner case and an outer side surface of the other inner case.

Abstract: A diesel locomotive burner arrangement for controlling the temperature of exhaust gas at the exhaust aftertreatment system thereby controlling the oxidation of soot within the aftertreatment system filters. The burner is arranged in isolation of the locomotive engine to ensure freedom from vibration and excessive thermal input, as well as ease of servicing.

Abstract: A turbocharger for an internal combustion engine, comprising a bearing housing, a rotating shaft coupled to the bearing housing, a compressor wheel mounted at one end of the rotating shaft, a compressor housing accommodating the compressor wheel and provided with an inlet and an outlet for an air stream, a turbine wheel mounted at the opposite end of the rotating shaft, and a turbine housing accommodating the turbine wheel and provided with an inlet and an outlet for an exhaust gas stream, wherein the bearing housing comprises a fastening flange suitable to be fixed to a component of the internal combustion engine, wherein the turbine housing is provided with a connecting pipe for fluidly connecting the turbine housing inlet with an exhaust manifold of the internal combustion engine, and wherein the connecting pipe includes means, for compensating axial thermal deformations thereof.

Abstract: A V-type engine includes two exhaust manifolds connected to two cylinder banks. First and second exhaust ports, respectively provided in the two cylinder banks, are disposed at an inner side of V-shaped lines. Each exhaust manifold includes N branch pipes and a collecting pipe, where N is an integer not less than 2. The N branch pipes are respectively connected to N exhaust ports including at least one of the first exhaust ports and at least one of the second exhaust ports. The collecting pipe is disposed adjacent to N cylinders that are aligned in a direction parallel or substantially parallel to a crank axis direction and extends from one end to the other end of the N cylinders.

Abstract: An exhaust device for a multi-cylinder engine for connecting both exhaust passage members with a communicating hole formed in each one when the two exhaust passage members are to be spaced apart. A base plate has a through hole communicating with the communicating hole and a cover plate for covering the outside of the base plate. The outer circumferential area of the through hole of the base plate overlaps the outer surface of the exhaust pipe with the entire outer circumferential area of the through hole is welded to the exhaust pipe. The edge portions on both sides of the cover plate are welded to the base plate so as to surround the outer side of the through hole. The area extending between edge portions on both sides of the cover plate is welded to the front and rear edge portions of the base plate.

Abstract: A mounting system for connecting an after-treatment component to a frame is disclosed. The mounting system may have a front center bracket connectable to a front end of the after-treatment component. The mounting system may further have a front link, which may have a first end connected to the front center bracket and a second end connectable to the frame. The mounting system may also have a rear center bracket connectable to a rear end of the after-treatment component. In addition, the mounting system may have a rear link, which may have a first end connected to the rear center bracket and a second end connectable to the frame.

Abstract: An exhaust manifold includes: an inlet portion which collects exhaust gas discharged through a first to a fourth exhaust ports; an outlet portion discharging the exhaust gas; and a tube portion connecting the inlet and the outlet portions. The inlet portion comprises: a first inlet portion one end of which communicates with the first and the second exhaust ports; and a second inlet portion one end of which communicates with the third and the fourth exhaust ports. Since the inlet portion is provided as two considering the combustion sequence, the productability and the economic feasibility can be enhanced, and the surrounding space can be enlarged to enhance the workability, and a simple exterior appearance can be obtained, and interference between exhaust gases can be effectively prevented, and since the size of the exhaust manifold can be increased, an engine load can be reduced to improve the fuel mileage.

Abstract: A work vehicle includes: a top having a first hole; a plate having a second hole and attached to the top with the second hole in alignment with the first hole; an exhaust pipe having an internal path and a flange projecting outward and abutting against and thus attached to the plate; and a tail pipe having a portion positioned in the first and second holes, and an end in the internal path of the exhaust pipe. The plate is disposed between the top and the flange and serves as a reference in attaching the flange to the top. Thus, a work vehicle that can facilitate disposing an exhaust pipe and a tail pipe concentrically and provide better workability in disposing the exhaust pipe and the tail pipe concentrically, and a method for manufacturing the work vehicle, can be provided.

Abstract: The invention relates to an exhaust gas treatment device for an exhaust system of a combustion engine, more preferably of a road vehicle, with a housing enveloping at least one interior space, and with at least one through-pipe penetrating the interior space without interruption and which at two fastening points distant from each other is connected to the housing in a fixed manner. For compensating thermally related expansion effects the through-pipe between the fastening points can comprise at least one expansion compensation section, in which a wall of the through-pipe comprises slits penetrating the wall alternating in circumferential direction and strips protruding relative to adjacent wall sections of the through-pipe.

Abstract: The invention relates to an exhaust gas treatment device for an exhaust system of a combustion engine, more preferably of a road vehicle, with a housing enveloping at least one interior space, and with at least one through-pipe penetrating the interior space without interruption and which at two fastening points distant from each other is connected to the housing in a fixed manner. For compensating thermally related expansion effects the through-pipe between the fastening points can comprise at least one expansion compensation section, in which a wall of the through-pipe comprises slits penetrating the wall alternating in circumferential direction and strips protruding relative to adjacent wall sections of the through-pipe.

Abstract: An exhaust treatment unit treats exhaust gas from an engine of a work vehicle. The exhaust treatment unit includes a diesel particulate filter device, a selective catalytic reduction device, a first support component and a second support component. The diesel particulate filter device treats the exhaust gas. The selective catalytic reduction device treats the exhaust gas. The first support component supports the diesel particulate filter device. The second support component supports the selective catalytic reduction device and the first support component. The first support component is detachable from the second support component.

Abstract: A curved-pipe portion curved so as to change the exhaust direction is provided to the downstream-side end section of the exhaust guide pipe and the external protective pipe, and the spacing between an end-section outer periphery of the exhaust guide pipe and an end-section inner periphery of the external protective pipe in the curved-pipe portion is configured so as to be greater on the side opposite the center of curvature of the curved-pipe portion than the side nearer thereto.

Abstract: A mounting foot for mounting an after-treatment component to a frame is disclosed. The mounting foot may have a pad connectable to the frame. The mounting foot may also have a slider slidably connected to the pad. In addition, the mounting foot may have a mounting bracket. The mounting bracket may have a first end connectable to the after-treatment component and a second end connected to the slider.

Abstract: The present invention relates to an exhaust-gas turbocharger (1) having a turbine housing (2) and having a manifold section (3) which is connected to the turbine housing (2), wherein the turbine housing (2) and the manifold section (3) are formed as a single-piece cast part.

Abstract: The present invention relates to an exhaust manifold for an internal combustion engine, in particular in a motor vehicle, comprising a housing from which a plurality of inlet pipes emanate, which, in the built-in state, lead to cylinders of the internal combustion engine, and comprising a flange, which is welded to the inlet pipes and which, in the built-in state, is screwed to the cylinder head of the internal combustion engine by means of a screw connection. The fatigue strength of the exhaust manifold can be improved by subdividing the flange into at least two partial flanges in a longitudinal direction of the exhaust manifold.

Abstract: Device for mechanically decoupled retention of components perfused by hot gas in an aircraft, with a coupling member for coupling to a component emitting hot gas and to a component accepting hot gas, with a holder, with a flange, and with a bellows, the holder being fittable to a housing or frame connected to the component emitting hot gas, the bellows being fastened by one end to the flange and by the other end to the holder, and the coupling member being fastened to the flange. By virtue of the device, both an angular misalignment and radial and axial positional misalignment can be equalized.

Abstract: An exhaust device includes a plurality of independent exhaust passages connected to an exhaust port of one cylinder or a plurality of cylinders that are non-sequential in exhaust order, and a mixing pipe into which exhaust that has passed through the respective independent exhaust passages flows. The downstream ends of the respective independent exhaust passages are connected in a bundled form to the upstream end of the mixing pipe. A cavity expansion chamber is disposed in an exhaust passage downstream from the mixing pipe. The cavity expansion chamber is disposed in a position (at a distance L2) such that, in the intermediate speed range, a negative pressure wave generated due to an exhaust pressure wave generated by opening an exhaust valve being reflected by the cavity expansion chamber reaches the exhaust port during an overlap period of the exhaust valve and an intake valve of the cylinder.

Abstract: An exhaust gas system includes a turbocharger housing and an exhaust manifold having manifold pipes and connected to the turbocharger housing. The turbocharger housing has a pipe collector extending in a direction of the exhaust manifold for connection of the manifold pipes.

Abstract: An exhaust gas apparatus suppresses sound pressure level from increasing, and reducing its weight and production cost without need of a sub-muffler in a tail pipe and a sound deadening device having an air column resonance of a large capacity provided at the upstream opened end of the tail pipe. The exhaust gas apparatus is provided with an exhaust gas pipe, an upstream opened end connected to the sound deadening device positioned at the upstream side of an exhaust gas discharging direction, and a downstream opened end through which the exhaust gas is discharged to the atmosphere. A plate is provided at least one of the upstream opened end and the downstream opened end in opposing relationship with the exhaust gas discharging direction, and formed with an opened portion. The exhaust gas pipe is formed at its peripheral wall axially inwardly spaced apart from the plate with a through bore.

Abstract: A support system for an exhaust aftertreatment system for a two-stroke locomotive diesel engine providing a secure mounting of certain components of the exhaust aftertreatment system to the locomotive structure while at the same time allowing for differential thermal expansion (and the resulting physical displacement) of the components. The support system further carries the physical mass of the components of the aftertreatment system while at the same time effectively isolating the aftertreatment system from external loads and forces caused by motions of the locomotive engine and the locomotive frame.

Abstract: An exhaust gas apparatus of an internal combustion engine is capable of suppressing the sound pressure level from being increased by the air column resonance in the tail pipe. The exhaust gas apparatus being provided with an exhaust gas pipe at the downstream side of an internal combustion engine in the exhaust gas direction of an exhaust gas flow, the exhaust gas pipe having an upstream opening end at one end portion thereof and connected with a sound deadening device at the upstream side in the exhaust gas direction of the exhaust gas flow, and a downstream opening end at the other end portion thereof for exhausting the exhaust gas flow to the atmosphere.

Abstract: An apparatus for treating exhaust includes a housing having an inlet and an outlet, the housing defining a chamber. The inlet is in fluid communication with a source of exhaust. A mixing tube is connected to the inlet. The mixing tube has at least two branches and a plurality of apertures defined in a wall of the mixing tube. A substrate is disposed between the mixing tube and the outlet. The at least two branches converge at an end section of the mixing tube to form a mixing loop.

Abstract: A mass damper method includes providing an electroactive polymer (7) and using the electroactive polymer (7) to manufacture a mass damper (6). The mass damper (6) for damping a vibrating system of a motor vehicle includes at least one of a damping body (10) forming a countervibrating mass with a damping spring (11) and a springy damping body (10) forming the countervibrating mass. The damping body (10) is indirectly or directly coupled with the vibrating system. The springy damping body (10) or the damping spring (11) includes an electroactive polymer (7). A motor vehicle exhaust system of an internal combustion engine is provided including an exhaust gas line (3) with an exhaust pipe (4), an exhaust gas-treating device (5) integrated in the exhaust pipe and the mass damper (6) coupled with the exhaust gas line.

Abstract: The present invention relates to a sliding seat for mounting a thermally impacted pipe on a structural part so as to be axially movable, in particular in an exhaust gas system of a combustion engine, with a bearing material which is radially supported against pipe on the outside thereof and which is fixed on structural part via a retaining pipe fastened on structural part.

Abstract: An exhaust gas cooler assembly with an internally located bypass tube, spaced apart from and disposed within a core passage, with an exhaust gas inlet manifold directing exhaust gas to a plurality of cooling passages, or to the bypass tube by means of control valves. Further provided is a detachable valve cartridge with an actuator, with all moving components being included within the valve cartridge and actuator.

Abstract: A bracket for connecting an after-treatment component to a frame is disclosed. The bracket may have a clevis connectable to the after-treatment component. The bracket may also have a front link coupler. The front link coupler may have a tang connected to the clevis. The front link coupler may also have a first flange extending outward from the tang and a second flange extending outward from the tang opposite the first flange. In addition, the front link coupler may have a third flange spaced apart from the first flange and extending outward from the tang and a fourth flange spaced apart from the second flange and extending outward from the tang opposite the third flange. The first, second, third, and fourth flanges may be connectable to the frame.

Abstract: A hydraulic motor having a cooling system includes a stator, a rotor that rotates and orbits in the stator, a drive link connected to the rotor, and a housing connected with the stator. The housing includes a working fluid inlet port, a working fluid outlet port, a cooling fluid inlet port, and a cooling fluid outlet port. Each port extends through the housing and is configured to connect with a different associated external fluid line. Pressurized fluid enters the working fluid inlet port to rotate and orbit the rotor en route to the working fluid outlet port. The cooling fluid ports are isolated from the working fluid inlet port and the working fluid outlet port within the housing.

Abstract: A sound attenuating heat exchanger for an internal combustion engine includes a housing, a barrier wall and a fin. The housing includes an exhaust inlet, an exhaust outlet, a coolant inlet and a coolant outlet. The exhaust inlet is connected to the exhaust outlet by an exhaust flow passage. The coolant inlet is connected to the coolant outlet by a coolant flow passage. The barrier wall fluidly separates the exhaust flow passage from the coolant flow passage. The fin extends from the barrier wall into the exhaust flow passage, and includes a resonator adapted to attenuate sound waves traveling through exhaust gas within the exhaust flow passage. The barrier wall and the fins are adapted to exchange heat energy between the exhaust gas flowing through the exhaust flow passage and coolant flowing through the coolant flow passage.

Abstract: An exhaust pipe structure of a vehicle having a left manifold disposed in front of an engine and a right manifold disposed behind the engine along a longitudinal direction of the vehicle, which are connected by an underbody catalytic converter, the exhaust pipe structure may include a left exhaust pipe connected to the left manifold and extending toward the rear of the engine, a right exhaust pipe having a straight portion connected to the right manifold and extending toward the front of the engine and a curved portion bending from the straight portion toward the rear of the engine, and a conjunction, one end of which is connected to and communicates with the end of the curved portion of the right exhaust pipe and the end of the left exhaust pipe and the other end of which is connected to the underbody catalytic converter.