EXHAUST DEVICE FOR ENGINE

• US 20100230204A1
• Filed: 03/02/2010
• Published: 09/16/2010
• Est. Priority Date: 03/16/2009
• Status: Active Grant

• Current Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Original Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Inventors: INOUE, Yusuke, NAKAMURA, Shigesato
• Granted Patent: US 7,971,682 B2
• Time in Patent Office: Days
• US Class Current: 181/255
• CPC Class Codes: F01N 1/04 having sound-absorbing materials in resonance chambers
• CPC Class Codes: F01N 2590/04 for motorcycles

Abstract

An exhaust device for an engine cam include a flow rectifying device for rectifying a flow of an exhaust gas. The flow rectifying device is disposed in an upstream end of an inner pipe, and comprises protrusions projecting inwardly. The exhaust gas engaging the flow rectifying device has passed through a curved portion of the inner pipe. The inner pipe also includes a muffler having a plurality of vent holes disposed in an inner portion thereof, and an outer pipe surrounding the inner pipe, defining an angular chamber therebetween.

Claims

1. An exhaust device for an engine, said exhaust device including a flow rectifying means for rectifying a flow of an exhaust gas, said flow rectifying means being disposed in an upstream end of an inner pipe, said flow rectifying means comprising protrusions projecting inwardly,

wherein the exhaust gas engaging said flow rectifying means has passed through a curved portion of the inner pipe, and wherein the inner pipe also includes a muffler having a plurality of vent holes disposed in an inner portion thereof, and an outer pipe surrounding the inner pipe, defining an angular chamber therebetween.

2. The exhaust device according to claim 1, wherein said flow rectifying means comprises a first flow rectifying member attached to the inner surface of the inner pipe, and a second flow rectifying member attached to the inner surface of the inner pipe, downstream of the first flow rectifying member, said first and second flow rectifying members having the protrusions projecting integrally therewith, inwardly from an inner surface of the upstream end of the inner pipe.

3. The exhaust device according to claim 1, wherein one of said protrusions is angularly disposed so as to be progressively spaced from the inner surface of the inner pipe downstream with respect to the direction in which the exhaust gas flows, and wherein the distance between the projecting end of the at least one protrusion and the inner surface of the inner pipe in a region where a pressure distribution of the exhaust gas in the inner pipe exhibits a highest pressure is greater than distances at other portions of the projecting end.

4. The exhaust device according to claim 2, wherein the first and second flow rectifying members include an arcuate cross-sectional shape in a plane perpendicular to an axis of the inner pipe.

7. The exhaust device according to claim 1, wherein said flow rectifying means is disposed downstream of said curved portion, on an outwardly disposed section thereof.

5. An exhaust device for an engine, comprising:

an exhaust pipe having an inner surface thereof and a curved portion configured to be attached to the engine at an upstream portion thereof, and configured to be attached to a muffler at a downstream portion thereof;

a protrusion projecting inwardly from an inner surface of the exhaust pipe, said protrusion disposed downstream of said curved portion,

wherein the protrusion is configured to rectify flow of exhaust gas which has passed through the curved portion.

6. The exhaust device according to claim 5, wherein said protrusion is disposed downstream of said curved portion, on an outwardly disposed section thereof.

8. An exhaust device for an engine, said exhaust device comprising:

an exhaust pipe having a curved portion at one end thereof, said curved portion being configured to be attached to an engine, the exhaust pipe also configured to be attached to a muffler at a downstream end thereof, whereby the muffler comprises an inner pipe having a number of vent holes thereupon, and an outer pipe surrounding the inner pipe, thereby defining an angular chamber between the outer pipe and the inner pipe;

at least one flow rectifying protrusion disposed on an inner surface of an upstream end of the inner pipe, said protrusion being configured to rectify flow of exhaust gas which has passed through the curved portion.

9. The exhaust device according to claim 8, comprising at least two flow rectifying protrusions, with a first flow rectifying protrusion being attached to the inner surface of the inner pipe, and a second flow rectifying protrusion being fixed to the inner surface of the inner pipe downstream of the first flow rectifying protrusion, with the first and second flow rectifying protrusions projecting integrally inwardly from the upstream end of the inner pipe.

10. The exhaust device according to claim 9, wherein the first protrusion is angularly disposed so as to be progressively from the inner surface of the inner pipe downstream with respect to the direction in which the exhaust gas flows there through, and wherein a distance between a projecting end of the first protrusion and the inner surface of the inner pipe, in a region where a pressure distribution of the exhaust gas in the inner pipe exhibits a highest pressure, is greater than the distances at other portions of the projecting end.

11. The exhaust device according to claim 10, wherein the first and second flow rectifying protrusions comprise an arcuate cross-sectional shape in a plane perpendicular to an axis of the inner pipe.

12. The exhaust device according to claim 11, wherein the at least one flow rectifying protrusion is disposed downstream of the curved portion, on an outwardly disposed section thereof.

13. An exhaust device for an engine, comprising:

an exhaust pipe having a curved portion at an upstream end thereof; and

at least one flow rectifying protrusion projecting inwardly from an inner surface of the exhaust pipe, said flow rectifying protrusion disposed downstream of the curved portion, said protrusion configured to rectify a flow of an exhaust gas which has passed through the curved portion.

14. The exhaust device according to claim 13, wherein the flow rectifying protrusion is disposed to project inwardly from an outward section of the exhaust pipe.