Motorcycle exhaust system

• US 20060053780A1
• Filed: 09/09/2005
• Published: 03/16/2006
• Est. Priority Date: 09/13/2004
• Status: Active Grant

• Current Assignee: Kawasaki Motors
• Original Assignee: Kawasaki Jukogyo Kabushiki Kaisha
• Inventors: Kikuchi, Hiroyuki, Onishi, Yoji, Yamamoto, Hidehiko, Yokoyama, Naoki
• Granted Patent: US 7,290,388 B2
• Time in Patent Office: Days
• US Class Current: 60/299
• CPC Class Codes: F01N 13/009 having two or more separate purifying devices arranged in series
• CPC Class Codes: F01N 13/017 the purifying devices are arranged in a single housing
• CPC Class Codes: F01N 2330/02 Metallic plates or honeycombs, e.g. superposed or rolled-up corrugated or otherwise deformed sheet metal
• CPC Class Codes: F01N 2590/04 for motorcycles
• CPC Class Codes: F01N 3/28 Construction of catalytic reactors
• CPC Class Codes: F01N 3/281 Metallic honeycomb monoliths made of stacked or rolled sheets, foils or plates
• CPC Class Codes: F01N 3/2842 specially adapted for monolithic supports, e.g. of honeycomb type F01N3/2853 - F01N3/2871 take precedence

Abstract

A motorcycle exhaust system includes a catalytic converter (43) disposed within an exhaust passage (37) for discharging exhaust gas (G) from a multi-cylinder combustion engine (E) and operable to purify the exhaust gas (G). An upstream end of the catalytic converter (43) has different regions (S1 and S2) communicated with upstream exhaust passage portions (37a and 37a), respectively, and a downstream end of the catalytic converter (43) is communicated with downstream exhaust passage portions (37b and 37b) in a number equal to or smaller than the number of the upstream exhaust passage portions (37a and 37a). Also, the catalytic converter (43) has a partition wall (43c) extending in a direction of flow of the exhaust gas (G) for allowing the exhaust gas (G) from the upstream exhaust passage portions (37a and 37a) to flow through the catalytic converter (43) without being mixed together.

Claims

1. A motorcycle exhaust system which comprises;

a catalytic converter disposed within an exhaust passage for discharging exhaust gas from a multi-cylinder combustion engine and operable to purify the exhaust gas;

wherein an upstream end of the catalytic converter has different regions communicated with a plurality of upstream exhaust passage portions of the exhaust passage, respectively, and a downstream end of the catalytic converter is communicated with downstream exhaust passage portion or portions of the exhaust passage in a number equal to or smaller than the number of the upstream exhaust passage portions; and

wherein the catalytic converter has a partition wall extending in a direction conforming to a direction of flow of the exhaust gas for allowing the exhaust gas from the upstream exhaust passage portions to flow through the catalytic converter without being mixed together.

2. The motorcycle exhaust system as claimed in claim 1, further comprising a partition plate provided on at least one of upstream and downstream sides of the catalytic converter within an exhaust pipe, forming a part of the exhaust passage, so as to extend in the direction of flow of the exhaust gas, the partition plate dividing the exhaust passage laterally.

3. The motorcycle exhaust system as claimed in claim 2, wherein the partition plate has a sectional shape taken in a direction perpendicular to the direction of flow of the exhaust gas, which shape has a corrugated portion.

4. The motorcycle exhaust system as claimed in claim 1, further comprising a sealing member disposed in between an outer peripheral surface of the catalytic converter and an inner peripheral surface of the exhaust passage for avoiding a communication between the upstream or downstream exhaust passage portions outside the catalytic converter.

5. The motorcycle exhaust system as claimed in claim 1, wherein the catalytic converter is of a honeycomb structure having pores oriented in the direction of flow of the exhaust gas.

6. The motorcycle exhaust system as claimed in claim 5, further comprising a partition plate provided on an upstream side of the catalytic converter within an exhaust pipe, forming a part of the exhaust passage, so as to extend in the direction of flow of the exhaust gas for dividing the exhaust passage laterally and wherein a portion of the catalytic converter corresponding to a downstream end of the partition plate serves as the partition wall.

7. The motorcycle exhaust system as claimed in claim 1, wherein the catalytic converter comprises a tubular body having a plurality of fine perforations and also having surfaces deposited with a catalyst and wherein the partition wall is disposed inside the tubular body.

8. The motorcycle exhaust system as claimed in claim 1, which comprises:

four upstream exhaust pipes connected to the combustion engine of a four-cylinder;

two intermediate exhaust pipes each fluidly connected with respective downstream ends of two of the four upstream exhaust pipes;

a single downstream exhaust assemblage pipe fluidly connected with respective downstream ends of the two intermediate exhaust pipes, the single downstream exhaust assemblage pipe being provided with the catalytic converter; and

a partition plate disposed at least upstream of or downstream of the catalytic converter within the single downstream exhaust assemblage pipe.

9. The motorcycle exhaust system as claimed in claim 8, wherein the catalytic converter is of a honeycomb structure having pores oriented in the direction of flow of the exhaust gas and wherein respective downstream ends of the two intermediate exhaust pipes are extended to a position immediately before the catalytic converter.