Sound waves of an amplitude having a waveform (first value as a function of time and a first maximum) pass into a manifold, which subdivides flow and sound into multiple paths of differing length, yielding transit times offsetting the arrival of each instance of the waveform at an outlet or exit. This minimizes the addition of energy (sound volume, amplitude) arriving at the exit or terminus from each path. Amplitude is thereby reduced (although the waveform shape remains), repeated and offset by the transit time delays of paths discharging at the terminus. One may select the number of paths based on a desired reduction in the sound amplitude. That number is approximately inversely proportional to the ratio of the reduction. For example, six unique paths in an experiment reduced original amplitude (sound volume) to a sixth at an exit.

An exhaust muffler has an outer cylinder into which an exhaust gas from an engine is introduced and a muffling member made of a foamed ceramic material. The outer cylinder has an inner cylinder through which the exhaust gas passes, a part of the muffling member is supported by an outer wall of the inner cylinder via a holding member. The inner cylinder includes, in an area where the inner cylinder overlaps with the muffling member with respect to axial direction of the inner cylinder, a porous wall portion formed with communication holes communicating an inside and an outside of the inner cylinder. The holding member is arranged at a position where it does not overlap with a part of the porous wall portion, so that muffling effect is enhanced, and the muffling member having a low resistance to impact forces can be supported stably by the inner cylinder.

An exhaust pulse balance chamber comprising a circular collar, mid-section that bulges at its center, skirt, and right and left legs, all of which are sealed to the exterior environment and in fluid communication with one another. The outer diameter of the skirt increases in width but not in depth from the proximal end of the skirt to the distal end of the skirt, which is configured to receive the right and left legs. Each leg is bent at a 30-degree angle relative to the central longitudinal axis of the exhaust pulse balance chamber. The invention includes a method of using the exhaust pulse balance chamber to convert a vehicle from a dual-in, single-out exhaust system to a dual-in, dual-out exhaust system.

A muffler for receiving exhaust gas from a combustion engine comprises a shell, first and second inlet pipes each having outlets providing exhaust gas to a mixing chamber within the shell, a first chamber and a second chamber positioned within the shell and a pair of communication pipes each including an inlet receiving exhaust gas from the mixing chamber. Each communication pipe includes an outlet providing exhaust to the second chamber. Each of the communication pipes further includes a Helmholtz opening positioned downstream of the mixing chamber. The Helmholtz openings are open to the first chamber.

An exhaust silencing device and system, a vehicle, and an exhaust silencing method. The exhaust silencing device comprises an air intake pipe (1), a main exhaust silencing cylinder (2), a main exhaust pipe (3), a multi-way valve (6), at least one auxiliary exhaust silencing device (4), and at least one auxiliary exhaust pipe (5); the multi-way valve (6) is in communication with the air intake pipe (1), the main exhaust pipe (3), and the auxiliary exhaust pipe (5); the main exhaust silencing cylinder (2) has one end in communication with the multi-way valve (6) by means of the main exhaust pipe (3), and another end in communication with the outside; and the auxiliary exhaust silencing device (4) has one end in communication with the multi-way valve (6) by means of the auxiliary exhaust pipe (5), and another end in communication with the outside.

A muffler for use with an internal combustion engine is provided. The muffler includes a first tube configured to receive a first exhaust stream. The first tube includes a first inlet portion, a first outlet portion spaced apart from the first inlet portion, and a first intermediate portion extending between the first inlet portion and the first outlet portion. The muffler also includes a second tube configured to receive a second exhaust stream. The second tube includes a second inlet portion, a second outlet portion spaced apart from the second inlet portion, and a second intermediate portion extending between the second inlet portion and the second outlet portion. The first intermediate portion and the second intermediate portion cross each other, are at least partially stacked on each other, and are in fluid communication with each other.

A muffler for an exhaust system of an internal combustion engine includes a muffler housing having a peripheral wall elongated along a longitudinal housing axis. The muffler has an end wall on each axial end region of the peripheral wall and a muffler insert, surrounded by the peripheral wall and supported on the peripheral wall. A retaining wall extends substantially in the direction of the longitudinal housing axis and a first exhaust-gas routing pipe is positioned with a first end region engaging in an opening in the peripheral wall and is secured to the peripheral wall and retained with a second end region on the retaining wall. The first exhaust-gas routing pipe is retained in its second end region on the retaining wall by force closure or interlocking.

A muffler for an exhaust system of an internal combustion engine includes a muffler housing having a peripheral wall elongated along a longitudinal axis of the muffler housing. The peripheral wall has first and second end walls. A muffler insert is surrounded by the peripheral wall and is supported thereon. The muffler insert has a retaining wall extending in a direction of the longitudinal axis. The peripheral wall has a peripheral wall opening and a first exhaust-gas routing pipe has a first end region and is positioned with the first end region thereof engaging in the peripheral wall opening. The first exhaust-gas routing pipe has a second end region and is secured by the second end region thereof to the retaining wall. The first exhaust-gas routing pipe is of multi-part configuration and has a first pipe part and a second pipe part.

A multi-mode muffler for an exhaust system of an internal combustion engine provides a rotary plate that modulates exhaust gas flow between a first and second flow path. Each flow path may provide different sound dampening characteristics, thereby providing different sound profiles with the same muffler. In a disclosed embodiment, the rotary plate is driven by a shaft coupled to an external actuator. Also, a third possible position of the rotary plate may allow flow through both the first and second flow paths, thereby providing a third possible noise profile. One of the sound profiles may be louder than the other thereby allowing the muffler to switch between “loud” and “quiet” modes of operation.

Exhaust systems for a vehicle are provided. In one example, an exhaust system includes a muffler, a first exhaust outlet pipe fluidly coupled to a first outlet of the muffler, a second exhaust outlet pipe fluidly coupled to a second outlet of the muffler, a bypass duct fluidly coupled to a third outlet of the muffler, and a combined X-Y shaped intersection at which the first exhaust outlet pipe, the second exhaust outlet pipe, and the bypass duct are fluidly coupled to each other.