A vehicle exhaust system includes a tubular component having an inner surface and an outer surface such that the inner surface defines a primary exhaust gas flow path. The tubular component extends along a central axis from an inlet end to an outlet end. The tubular component includes at least one ridge extending at least partly along a circumference of the tubular component. The at least one ridge includes a first portion angularly extending inwardly from the tubular component, and a second portion disposed downstream of the first portion. The second portion angularly extends inwardly from the tubular component. In some cases, the second portion defines a plurality of openings extending therethrough and spaced apart from each other. In some cases, the tubular component defines a plurality of tube openings disposed downstream of the at least one ridge.

A method for manufacturing a vehicle muffler includes: forming a tubular body (6; 91, 92) from a nonwoven fabric (2; 2A, 2B) composed of inorganic fibers (11) each being in a filament form; inserting and installing the tubular body (6) as a sound-absorbing material into a space (S) between an inner pipe (72; 81) and an outer pipe (71; 821, 822) of an inner-outer double pipe constituting a vehicle muffler. The tubular body (6) may be obtained by applying a binder (3) to one surface (2a) of the nonwoven fabric (2), then rolling the nonwoven fabric (2) into a tubular shape with the surface (2a) having the binder (3) applied thereto facing inward, infiltrating additional binder (3) into an outer peripheral surface of the tubular-shaped nonwoven fabric (2), and then heating the tubular-shaped nonwoven fabric (2) to a predetermined temperature to harden the binder (3).

A vehicle exhaust system includes a tubular component having an inner surface and an outer surface. The vehicle exhaust system also includes at least one opening defined by the tubular component. The at least one opening extends through each of the inner surface and the outer surface. The vehicle exhaust system further includes a patch adapted to cover the at least one opening. The patch includes a first portion extending parallel to the central axis. The first portion defines a plurality of pores. The first portion covers the at least one opening. The patch also includes a second portion extending away from the first portion. The first portion has a first thickness and the second portion has a second thickness.

A muffler for an engine includes a muffler body, at least one partition wall, and at least one reinforcing plate. The muffler body has an inner space formed by a shell. The partition wall includes a flange portion which is in tight contact with an inner surface of the shell, and the partition wall divides the inner space of the muffler body into a plurality of chambers. The reinforcing plate is welded on an outer surface of the shell at a position facing the flange portion of the partition wall.

A vehicle exhaust system and method of minimizing a leaked mass flow comprising an exhaust component defining a central axis and having an inner surface and an outer surface, such that the inner surface defines a primary exhaust gas flow path extending along the central axis from an inlet to an outlet, and a surface component having a hood spaced from the exhaust component to define a reservoir having a reservoir volume (V), the reservoir comprising a reservoir inlet fluidly coupled to the primary exhaust gas flow path and defining an inlet area (A), and a reservoir outlet fluidly coupled to an outside environment. The reservoir volume and inlet area having a defined relationship. The reservoir volume and a mass flow through the inlet area having a defined relationship.

A two-stroke engine exhaust resonator with an exhaust gas catalytic converter comprising an inlet opening, wherein the inlet opening is followed by the first end of a stabilizing tube with a catalytic converter mounted thereon, characterized in that the other end of the stabilizing tube is directed towards the primary reflective surface, the primary reflective surface is followed by the first end of a resonator casing, which is surrounding the stabilizing tube, wherein the resonator casing exceeds at least over a part of the catalytic converter on the stabilizing tube, wherein a resonator outlet opening is arranged in the resonator casing between its first and second end or in the primary reflective surface, and at least a part of the resonator casing surrounding the stabilizing tube is surrounded by a cooler.

A sound suppression assembly is provided for absorbing acoustic energy from an air circulation device. The assembly includes an air circulation device, such as an axial fan, and a plurality of sparsely-arranged two-sided Helmholtz unit cells disposed in a periodic array. Each unit cell includes a lossy resonator and a lossless resonator. The lossy resonator includes a first chamber portion bounded by at least one first boundary wall defining a first chamber volume, and a first neck forming an opening in the first chamber portion. The lossless resonator includes a second chamber portion bounded by at least one second boundary wall defining a second chamber volume, and a second neck forming an opening in the second chamber portion. The unit cells can be positioned in a circular pattern with the first neck of the lossy resonators directed to a source of acoustic energy from the air circulation device.

A method for manufacturing a vehicle muffler includes: forming a tubular body (6; 91, 92) from a nonwoven fabric (2; 2A, 2B) composed of inorganic fibers (11) each being in a filament form; inserting and installing the tubular body (6) as a sound-absorbing material into a space (S) between an inner pipe (72; 81) and an outer pipe (71; 821, 822) of an inner-outer double pipe constituting a vehicle muffler. The tubular body (6) may be obtained by applying a binder (3) to one surface (2a) of the nonwoven fabric (2), then rolling the nonwoven fabric (2) into a tubular shape with the surface (2a) having the binder (3) applied thereto facing inward, infiltrating additional binder (3) into an outer peripheral surface of the tubular-shaped nonwoven fabric (2), and then heating the tubular-shaped nonwoven fabric (2) to a predetermined temperature to harden the binder (3).

A muffler, for an internal combustion engine exhaust system, includes a muffler housing (12) with a housing jacket (14) elongated in a housing longitudinal axis (A) direction and with an outer panel (16) connected to the housing jacket at both axial end areas thereof to define a muffler interior (18). An inner panel (20) is arranged in and divides the muffler interior. A muffling unit (24) includes an exhaust-gas-carrying inner pipe (26), an outer pipe (28) enclosing the inner pipe and muffling material (32) arranged between the inner pipe and the outer pipe. The inner pipe is accommodated in an opening (48) of an inner panel and in an opening (40) of one of the outer panels or of an additional inner panel. The outer pipe is permanently connected to the inner panel or/and to one of the outer panels or to the additional inner panel.

A lightweight and compact muffler device that can be installed in a limited space in an inside of a generator. A top cover and an undercover (end cover) provided on a top and a bottom of a vertically disposed casing are each formed in substantially trapezoidal shape. Thereby, an inner capacity of the casing can be secured to be large, as a result of which, a size of the muffler device can be made compact, and no extra component is required, so that reduction in manufacturing cost and reduction in weight can be achieved. Since the casing is disposed vertically, it is possible to install the casing even when an installation space is small in an inside of a housing of a generator, and it is possible to make the generator compact.