Controllable muffler system for internal combustion engine

• US 20020033302A1
• Filed: 09/12/2001
• Published: 03/21/2002
• Est. Priority Date: 09/11/2000
• Status: Active Grant

• Current Assignee: Calsonic Kansei Corporation, Nissan Motor Co., Ltd.
• Original Assignee: Calsonic Kansei Corporation & Nissan Motor Company Limited
• Inventors: Kaneko, Yukio, Kijima, Atsushi, Horiuchi, Shinichi, Norikawa, Tanomo, Takeuchi, Kai
• Granted Patent: US 6,755,279 B2
• Time in Patent Office: Days
• US Class Current: 181/232
• CPC Class Codes: F01N 1/089 using two or more expansion chambers in series F01N1/083, F01N1/084, F01N1/086 take precedence
• CPC Class Codes: F01N 1/10 in combination with sound-absorbing materials F01N1/125 takes precedence
• CPC Class Codes: F01N 1/165 for adjusting flow area
• CPC Class Codes: F01N 1/166 for changing gas flow path through the silencer or for adjusting the dimensions of a chamber or a pipe F01N1/165 takes precedence

Abstract

A controllable muffler system is sued for use with an engine that produces a power by burning fuel. The system comprises a first passage section extending from the engine for having an exhaust gas of the engine flow therethrough. The first passage section has a catalytic converter mounted thereon. The system further comprises a dual passage section including second and third passage sections which extend separately from an end of the first passage section. The second passage has a control valve for controlling the flow rate of the exhaust gas flowing therethrough. The system further comprises a fourth passage section extending from respective ends of the second and third passage sections to the open air. The fourth passage section has a rear muffler mounted thereon. The system further comprises a control unit which controls the control valve of the second passage section in accordance with an operation condition of the engine.

Claims

1. A controllable muffler system for use with an engine that produces a power by burning fuel, comprising:

a first passage section extending from said engine for having an exhaust gas of the engine flow therethrough, said first passage section having a catalytic converter mounted thereon;

a dual passage section including second and third passage sections which extend separately from an end of said first passage section, said second passage having a control valve for controlling the flow rate of the exhaust gas flowing therethrough;

a fourth passage section extending from respective ends of said second and third passage sections to the open air, said fourth passage section having a rear muffler mounted thereon; and

a control unit which controls said control valve of the second passage section in accordance with an operation condition of the engine.

2. A controllable muffler system as claimed in claim 1, in which at least one of said second and third passage sections has a center muffler mounted thereon.

3. A controllable muffler system as claimed in claim 2, in which said center muffler is mounted on said second passage section, and in which said control valve is positioned upstream of said center muffler.

4. A controllable muffler system as claimed in claim 2, in which said center muffler is mounted on said second passage section, and in which said control valve is positioned downstream of said center muffler.

5. A controllable muffler system as claimed in claim 2, in which said center muffler is mounted on said third passage section.

6. A controllable muffler system as claimed in claim 1, in which said second passage section is constructed to have a gas flow resistance which is smaller than that of said third passage section.

7. A controllable muffler system as claimed in claim 1, in which said control unit controls said control valve in accordance with an operation speed of said engine.

8. A controllable muffler system as claimed in claim 7, in which said control unit closes said control valve when the engine is under a low speed operation and opens said control valve when the engine is under a middle/high speed operation.

9. A controllable muffler system as claimed in claim 1, further comprises a front muffler which is mounted on the passage section between said catalytic converter and an upstream end of said dual passage section.

10. A controllable muffler system as claimed in claim 2, in which said rear muffler of said fourth passage section comprises:

a cylindrical shell having front and rear ends closed;

three partition panels arranged in said cylindrical shell to define first, second, third and fourth chambers in the same;

two inlet pipes each being inserted into the cylindrical shell and led to said third chamber, the two inlet pipes being connected to the ends of said second and third passages sections respectively;

two outlet pipes each extending through the cylindrical shell from said first chamber to the open air;

two inner pipes each extending between said first and third chambers through said second chamber; and

a restricted opening formed in one of the partition panels to communicate a restricted communication between said third and fourth chambers.

11. A controllable muffler system as claimed in claim 10, further comprising a plurality of small openings formed in given portions of the two inlet pipes, two outlet pipes and two inner pipes, said given portions being exposed to said second chamber thereby to cause said second chamber to serve as a resonance chamber.

12. A controllable muffler system as claimed in claim 11, in which said two outlet pipes have each a given portion wrapped with a sound absorbing material, so that the given portions of the outlet pipes serve as sound absorbing chambers.

13. A controllable muffler system as claimed in claim 2, in which said second and third passage sections have respective center mufflers mounted thereon, and in which said control valve is positioned downstream of the center muffler of said second passage section.

14. A controllable muffler system as claimed in claim 13, in which the center muffler mounted on said second passage section comprises:

a cylindrical shell having front and rear ends closed;

apertured panels arranged in said shell;

an inlet pipe extending from the end of said first passage section, said inlet pipe being inserted into the cylindrical shell from said front end and led to a rear portion of the interior of said cylindrical shell to constitute an expansion chamber therein; and

an outlet pipe which extends in the cylindrical shell from a front portion of the interior of said cylindrical shell and is led to an upstream end of said fourth passage section, said outlet pipe having an exposed portion on which said control valve is mounted.

15. A controllable muffler system as claimed in claim 14, in which said outlet pipe has a plurality of small openings at a given portion exposed to a generally middle part of the interior of said cylindrical shell.

16. A controllable muffler system as claimed in claim 15, in which the center muffler mounted on said third passage section comprises:

a cylindrical shell having front and rear ends closed;

a partition panel installed in said cylindrical shell to define therein an expansion chamber and a resonance chamber;

apertured panels arranged in said resonance chamber;

an inlet pipe extending from the end of said first passage section, said inlet pipe being inserted into the cylindrical shell from said front end and led to a rear portion of the interior of the cylindrical shell; and

an outlet pipe which extends in the cylindrical shell from a front portion of said interior of the cylindrical shell and is led to the upstream end of said fourth passage section.

17. A controllable muffler system as claimed in claim 16, in which said inlet pipe has a plurality of small openings at a portion exposed to said expansion chamber, and in which said outlet pipe is formed at a given portion thereof with a plurality of openings exposed to said resonance chamber, said given portion being wrapped with a sound absorbing material, so that the given portion of the outlet pipe serves as a sound absorbing chamber.

18. A controllable muffler system for use with an internal combustion engine, comprising:

a first passage section extending from said engine for having an exhaust gas of the engine flow therethrough, said first passage section having a catalytic converter and a front muffler mounted thereon;

a dual passage section including second and third passage sections which extend separately from an end of said first passage section, said second passage having a control valve for controlling the flow rate of the exhaust gas flowing therethrough;

a fourth passage section extending from respective ends of said second and third passage sections to the open air, said fourth passage section having a rear muffler mounted thereon; and

a control unit which controls said control valve of the second passage section in accordance with an operation condition of the engine.