An exhaust gas purification system for diesel engines of utility motor vehicles, includes an oxidation catalytic converter disposed in an exhaust tract, a reducing agent dosing device having a reducing agent injection device, a reducing agent decomposition device, a soot particle separator, a reduction catalytic converter and a muffler for the exhaust gases. The oxidation catalytic converter is disposed within a minimum distance directly downstream of outlet valves of the engine and a maximum distance of 0.75 m from an exhaust collecting pipe or an outlet of a turbocharger. The reducing agent decomposition device, the soot particle separator and the reduction catalytic converter are disposed separately from the oxidation catalytic converter.

The exhaust pipe comprises an inlet pipe, an outlet pipe and a bend portion arranged between the inlet pipe and the outlet pipe. The bend portion comprises an inlet bend and an outlet bend, wherein a central bend portion defines an intermediate section of inlet bend and outlet bend and wherein the inlet bend and the outlet bend each cover 50 percent of the total bend angle covered by the bend portion. The central bend portion comprises a diameter, which is smaller than a diameter of the inlet bend and of the outlet bend in a bending plane. In addition a bend radius R of the bend portion varies along the bend portion such that a bend radius of the inlet bend is larger than a bend radius of the outlet bend.

Waveguide or flow guide surfaces can improve the efficiency of fluid flow through tubes or over surfaces. When incorporated in a tube, the waveguides improve flow and function as sound absorbers making them useful in engine mufflers, firearm silencer/suppressors and jet engine exhaust attenuators. On surfaces, the waveguides can reduce fluid drag and find use on projectiles (e.g., bullets), airfoils for aircraft, and land borne vehicles. The waveguide array in either a tubular chamber or on a surface comprises a plurality of successive wave-like undulations inclined generally in the direction of flow and when employed in tubes extending inwardly to permit an unobstructed path for the fluid gas from entry to exit. The waves define annular wave cavities between their successive inwardly extending edges and the wall of the chamber with each cavity having a cavity mouth open to the unobstructed path. The waveguides are sized and spaced so that gas vortices are created within the cavities when gas flow occurs which vortices create a fluid boundary layer that assists the gas flow.

In inline four cylinder internal combustion engine (1), exhaust ports for a #2 cylinder and a #3 cylinder merge inside cylinder head (3) and form an opening serving as a single collective exhaust port. Exhaust manifold (5) has individual exhaust pipes (6, 7) for #1 and #4 cylinders and collective exhaust pipe (8), and the leading ends of these three exhaust pipes (6, 7, 8) are connected to catalytic converter (11). Exhaust gas introduction angle (θ2) of each of individual exhaust pipes (6, 7) is larger by 30-60 degrees than exhaust gas introduction angle (θ1) of collective exhaust pipe (8). Consequently, flow velocity distribution and temperature distribution in a catalyst carrier become uniform.

The present invention relates to a manifold for receiving exhausts from a multi-cylindrical internal combustion engine. The internal combustion engine has such a firing order that the riser in the manifold receives exhausts from two cylinders during an overlapping stage, simultaneously via an inlet opening arranged upstream and from an inlet opening arranged downstream in the riser. The riser comprises a substantially constant cross sectional area, except in one area, which is located in a position in connection with the inlet opening arranged downstream of the two inlet openings, receiving exhausts simultaneously. Said area has a geometry facilitating receipt and flow of exhausts in the predetermined direction in the riser, on occasions when the two inlet openings receive exhausts simultaneously.

A muffler for an exhaust system includes an exhaust gas duct pipe (20) and a wall (26). The wall (26) is connected to the exhaust gas duct pipe (20) in a first connection area (24) thereof by a thread meshing.

An exhaust muffler is made up of a plurality of layers including an exhaust passage pipe and expansion chambers, and includes a front assembly and a rear assembly sub-assembled separately from the front assembly. The front assembly includes a front exhaust passage pipe, a front muffler body disposed in covering relation to the outside of the front exhaust passage pipe and cooperating with the front exhaust passage pipe in making up double-walled pipes, and an exhaust valve disposed in the front exhaust passage pipe. The rear assembly includes a rear exhaust passage pipe and a rear muffler body disposed in covering relation to the outside of the rear exhaust passage pipe and cooperating with the rear exhaust passage pipe in making up double-walled pipes. There is thus provided an exhaust device for an internal combustion engine in which the accuracy of a position where the exhaust valve is installed is high.

A sinuous balanced mid-pipe exhaust system has a straight mid-pipe and a sinuous mid-pipe disposed intermediate manifold and muffler. The manifold has a differential bilateral manifold pipe length. The longer manifold pipe connected to the straight mid-pipe and the shorter manifold pipe connected to the sinuous mid-pipe. Sinuous mid-pipe has 2-3 sinusoidal curved segments such that a sinuous gas flow path therethrough substantially equals the straight pipe flow path length and the manifold differential pipe length. The method balances and equalizes gas flows by defining straight gas flow path, having a path length and defining a sinuous gas flow path with at least two sinusoidal segments which is equal to the path length and the differential path length.

An exhaust duct assembly for conveying exhaust gases emanating from a combustion zone to atmosphere is disclosed. The assembly includes: an exhaust gas outlet for exhausting exhaust gas into the atmosphere; and an acoustic duct portion located upstream of the exhaust gas outlet, the acoustic duct portion having a peripheral wall defining a through-passage arranged and constructed to promote propagation of sound there-through. The acoustic duct portion has a length in a flow direction that is at least 50% of an average hydraulic diameter of the through-passage.

An aftertreatment component includes an inlet connector tube, an outlet connector tube, a chamber, a flow dissipater, and a substrate. The inlet connector tube receives exhaust gasses. The chamber is between the inlet connector tube and the outlet connector tube. The flow dissipater is positioned around the inlet connector tube and within the chamber. The flow dissipater receives the exhaust gasses from the inlet connector tube and includes a plurality of perforations. The plurality of perforations defines an open area of the flow dissipater. The open area of the flow dissipater is greatest proximate to the inlet connector tube and progressively decreasing proximate to the outlet connector tube. The substrate is positioned within the chamber and receives the exhaust gasses from the flow dissipater and provides the treated exhaust gasses to the outlet connector tube. The exhaust gases are expelled through the flow dissipater via the plurality of perforations.