Exhaust system in internal combustion engine

• US 5,712,454 A
• Filed: 01/26/1996
• Issued: 01/27/1998
• Est. Priority Date: 01/27/1995
• Status: Expired due to Fees

• Current Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company), Yutaka Giken Company Limited (Honda Motor Company)
• Original Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company), Yutaka Giken Company Limited (Honda Motor Company)
• Inventors: Matsushima, Ryoichi, Tsuda, Kazuhiro, Muramatsu, Katsunori, Hirokawa, Isao, Ozawa, Hidenori
• Primary Examiner(s): Dang, Khanh
• Application Number:
  US08/592,523
• Time in Patent Office: 732 Days
• Field of Search: 181/228, 181/237, 181/239, 181/264, 181/265, 181/266, 181/269, 181/272, 181/282, 181/226, 181/254
• US Class Current: 181/226
• CPC Class Codes: F01N 1/084 the gases flowing through the silencer two or more times longitudinally in opposite directions, e.g. using parallel or concentric tubes
• 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
• CPC Class Codes: F01N 1/24 by using sound-absorbing materials F01N1/04, F01N1/06, F01N1/10, F01N1/14, F01N1/16 take precedence
• CPC Class Codes: F01N 2470/02 Tubes being perforated
• CPC Class Codes: F01N 2470/14 Plurality of outlet tubes, e.g. in parallel or with different length

Abstract

An exhaust system in an internal combustion engine includes a flow rate regulating valve which is positioned in an intermediate portion of an exhaust gas flow passage. The flow rate regulating valve has a rotary shaft rotatably supported in a valve housing, and a rotationally biasing spring mounted between the rotary shaft and the valve housing which provides a spring force to rotationally bias the rotary shaft. In the exhaust system, an axially biasing spring is mounted separately from the rotationally biasing spring between the valve housing and the rotary shaft for biasing the rotary shaft in an axial direction. The rotary shaft is provided with an abutment surface which faces in the one axial direction, and the valve housing is provided with a limiting portion which abuts against the abutment surface to limit the axial movement of the rotary shaft. Thus, the rotary shaft is biased in the one axial direction by the axially biasing spring, and the abutment surface of the rotary shaft is urged against the limiting portion of the valve housing, thereby avoiding the axially chattering of the rotary shaft.

Claims

1. An exhaust system in an internal combustion engine, said exhaust system comprising a gas flow passage having an intermediate portion, a flow rate regulating valve means which is positioned in said intermediate portion of said exhaust gas flow passage, said valve means having a valve housing and rotary shaft rotatably supported in said valve housing, a valve member secured to said rotary shaft, a rotationally biasing spring mounted between said rotary shaft and said valve housing, to provide a spring force for rotationally biasing said rotary shaft, and an axially biasing spring mounted separately from said rotationally biasing spring between said valve housing and said rotary shaft for biasing said rotary shaft in an axial direction, wherein said rotary shaft is provided with an abutment surface facing in the axial direction, and said valve housing is provided with a limiting portion which abuts against said abutment surface to limit the axial movement of said rotary shaft.

2. An exhaust system in an internal combustion engine according to claim 1, further including a spring bearing member fixed at one end of said rotary shaft, said rotationally biasing spring and said axially biasing spring being positioned between said spring bearing member and said valve housing, wherein one of said rotationally biasing spring and said axially biasing spring surrounds the other spring around said rotary shaft.

3. An exhaust system in an internal combustion engine, said exhaust system comprising an exhaust silencer having a first shell and a flow rate regulating valve means having a valve member and a valve housing, said valve member being operatively positioned within said valve housing positioned within said first shell of said silencer, spring means for biasing said valve member in a direction to increase a flow resistance, a case member and a second shell secured to said first shell, wherein a spring chamber is formed between said case member and said second sheel, said spring chamber being isolated from the inside of said first shell and said valve housing and also isolated from the outside of said first shell;

and a rotationally biasing spring positioned in said spring chamber for biasing said valve member in a direction to increase the flow resistance.

4. An exhaust system in an internal combustion engine according to claim 3, wherein said first shell includes a bore therein, wherein said rotationally biasing spring can be inserted or removed therethrough, and wherein said second shell is detachably secured to said first shell and has an outwardly bulged sectional shape for covering said bore.

5. An exhaust system in an internal combustion engine, said exhaust system comprising a silencer having a shell;

a plurality of silencing chambers formed in said shell and a pipe interconnecting two of said silencing chambers; and

a flow rate regulating valve including a valve housing and a valve member operably positioned within said valve housing, said valve member being subjected to an exhaust gas pressure in a direction to decrease the flow resistance in said flow regulating valve, and being biased by a spring in a direction to increase the flow resistance, wherein the flow rate regulating valve is mounted to an outlet side of said pipe, and wherein said valve member forms a flow-in chamber between said valve member and said valve housing and has an outer edge which is in proximity to and opposed to an inner surface of said valve housing, said valve member being positioned within said valve housing for movement between a position to minimize a volume of said flow-in chamber and a position to maximize the volume of said flow-in chamber, said valve housing including an inlet pipe connected to said pipe and protruding into said flow-in chamber, said flow-in chamber having at an inner end thereof an opening which is opposed to said valve member, and an outlet window, wherein the area facing said flow-in chamber is increased as said valve member is operated from a communication start point established in an operational range of said valve member in a direction to increase the volume of said flow-in chamber.