Muffler for motor vehicles

Patent metadata

Field	Value
Publication number	US-10823022-B2
Application number	US-201716346668-A
Country	US
Kind code	B2
Filing date	Nov 3, 2017
Priority date	Nov 4, 2016
Publication date	Nov 3, 2020
Grant date	Nov 3, 2020

Abstract

A muffler ( 4 ) for motor vehicles comprising an intake pipe ( 8 ) of the exhaust gases that separates, at a fork ( 10 ), into a main pipe ( 12 ) and a secondary pipe ( 16 ), a muffler body ( 24 ) which delimits an expansion volume ( 28 ) and houses at least partly the main pipe ( 12 ) and the secondary pipe ( 16 ), wherein the intake pipe ( 8 ) of the exhaust gas is in fluid continuous connection with the main pipe ( 12 ) through the secondary pipe ( 16 ), and wherein the main pipe ( 12 ) comprises, downstream of the fork ( 10 ), a throttle valve ( 32 ) which allows or prevents a further fluidic connection of the intake pipe ( 8 ) of exhaust gas with the main pipe ( 12 ), and an output of the exhaust gases ( 40 ), for the expulsion of the gases from the muffler pipe ( 4 ).

First claim

The invention claimed is:

1. Muffler for motor vehicles comprising:
an intake pipe of exhaust gas which separates, at a fork, into a main pipe and a secondary pipe,
a muffler body which delimits an expansion volume and houses at least partially the main pipe and the secondary pipe,
wherein the intake pipe of the exhaust gas is in fluid continuous connection with the main pipe through the secondary pipe, and
wherein the main pipe comprises, downstream of the fork, a throttle valve which allows or prevents a further fluidic connection of the intake pipe of exhaust gas with the main pipe, and an output of the exhaust gases, for the expulsion of the gases from the muffler;
wherein the main pipe, at a first portion contained in the expansion volume, comprises a plurality of inlet holes suitable to allow leakage into the main pipe of the exhaust gases expanded in the expansion volume, coming from an open end of the secondary pipe;
wherein the muffler body comprises a separator septum which divides the muffler body into the expansion volume and a second portion which ends with the output of the exhaust gases; and
wherein an end portion of the main pipe housed in said second portion comprises damping holes surrounded by sound absorbent material fitted around the end portion of the main pipe.

2. Muffler for motor vehicles according to claim 1 , wherein the secondary pipe is at least partially contained in a containment tube fitted around the secondary pipe so as to delimit therewith an interspace, the containment tube having a closed bottom and an opposite open end fluidically connected with the expansion volume, the closed bottom being arranged facing an exhaust opening of the secondary pipe so as to convey the exhaust gases output from said exhaust opening of the secondary pipe towards said open end, prior to a counter current path, in a portion of said interspace defined between the exhaust opening of the secondary pipe and the open end, the open end being fluidically connected with the main pipe.

3. Muffler for motor vehicles according to claim 2 , wherein the containment tube is arranged coaxially to the secondary pipe, so as to delimit with the secondary pipe the interspace flowing into the open end.

4. Muffler for motor vehicles according to claim 2 , wherein the open end of the containment tube has a circular crown cross-section, with respect to a plane having a cross-section perpendicular to a main longitudinal direction of the secondary pipe, said circular crown cross-section being defined between the containment tube and the secondary pipe.

5. Muffler for motor vehicles according to claim 1 , wherein the main pipe and the secondary pipe have different through cross-sections for the exhaust gases.

6. Muffler for motor vehicles according to claim 1 , wherein the secondary pipe has a through cross-section between 20% and 50% of a through cross-section of the main pipe.

7. Muffler for motor vehicles according to claim 2 , wherein the containment tube is fitted around the secondary pipe for a portion equal to at least 30% of the length of the secondary pipe.

8. Muffler for motor vehicles according to claim 2 , wherein said interspace has a through cross-section of the exhaust gases not less than a through cross-section of the secondary pipe, said through cross-section of the interspace and the through cross-section of the secondary pipe being measured perpendicular to a main longitudinal direction of the secondary pipe itself.

9. Muffler for motor vehicles according to claim 2 , wherein said separator septum supports at least partly the containment tube.

10. Muffler for motor vehicles according to claim 1 , wherein the throttle valve comprises a partition that opens in the opposite direction to the flow of gas coming from the intake pipe, and comprises a stop ledge which realizes an undercut to the direction of the flow of the exhaust gases, in a closed configuration of the partition.

11. Muffler for motor vehicles according to claim 10 , wherein said partition is hinged at a hinge point fixed to the main pipe.

12. Muffler for motor vehicles according to claim 10 , wherein the main pipe, at said partition, comprises a housing seat of said partition in an open configuration of the partition.

13. Muffler for motor vehicles according to claim 10 , wherein the partition is operatively connected to motor means for the transition of the partition from an open to the closed configuration.

14. Muffler for motor vehicles according to claim 10 , wherein said partition comprises a concavity facing in the direction of the exhaust gases coming from the intake pipe.

Assignees

• Piaggio & C Spa

Inventors

• Soatti Piero
• Bellato Francesco

Classifications

• F01N1/00

  Silencing apparatus characterised by method of silencing · CPC title

• F01N1/08 Primary

  by reducing exhaust energy by throttling or whirling · CPC title

• F01N2410/00

  By-passing, at least partially, exhaust from inlet to outlet of apparatus, to atmosphere or to other device · CPC title

• F01N1/16

  by using movable parts · CPC title

• F01N2470/24

  Concentric tubes or tubes being concentric to housing, e.g. telescopically assembled · CPC title