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JP-7855021-B2 - Exhaust system

JP7855021B2JP 7855021 B2JP7855021 B2JP 7855021B2JP-7855021-B2

Inventors

  • 倉澤 侑史
  • 飯村 秀士
  • ヴ マン クオン

Assignees

  • 本田技研工業株式会社

Dates

Publication Date
20260507
Application Date
20240329

Claims (7)

  1. In an exhaust system (30) attached to a power unit (P), which has a muffler (32) housing a catalytic converter (C), The housing (41) that houses the catalyst device (C) is provided with an exhaust pipe (50) disposed downstream in the flow direction of the exhaust gas (G) of the power unit (P), The exhaust pipe (50) is supported so as to be slidable in the flow path direction relative to the housing (41), An exhaust system characterized in that the rear portion of the exhaust pipe (50) is slidably supported with respect to a second bulkhead (44) fixed to the muffler (32) .
  2. The exhaust system according to claim 1, characterized in that the exhaust pipe (50) is housed inside the muffler (32).
  3. An exhaust gas sensor (64) for detecting the components of the exhaust gas (G) is attached to the exhaust pipe (50). The exhaust device according to claim 1, characterized in that the exhaust pipe (50) is slidably supported with respect to an intervening pipe (45) fixed to the downstream end of the housing (41).
  4. The exhaust system according to claim 3, characterized in that the exhaust pipe (50) is attached to the muffler outer shell (39) via a boss (63) and a support plate (61) that support the exhaust gas sensor (64).
  5. The exhaust system according to claim 1, characterized in that the rear end of the exhaust pipe (50) is open to the expansion chamber of the muffler (32).
  6. The exhaust system according to claim 3, characterized in that the exhaust gas sensor (64) is mounted at a position upstream of the central portion (Lh) of the total length (L) of the exhaust pipe ( 50 ) in the flow direction of the exhaust gas (G).
  7. The exhaust pipe (50) is composed of a plurality of members (51, 52), The exhaust system according to claim 3 or 6 , characterized in that the exhaust gas sensor (64) is attached to the most upstream of the plurality of members (51, 52).

Description

This invention relates to an exhaust system, and more particularly to an exhaust system equipped with a catalytic converter for purifying exhaust gases from an internal combustion engine. Exhaust systems equipped with catalytic converters to purify exhaust gases from internal combustion engines have been known for some time. Patent Document 1 discloses a configuration in which a cylindrical catalytic converter is placed inside the muffler of an exhaust system, and exhaust pipes are connected to both the upstream and downstream ends of the catalytic converter in the direction of the exhaust gas flow path. Japanese Patent Publication No. 2017-227157 This is a right side view of a motorcycle equipped with an exhaust system according to this embodiment.This is a cross-sectional view taken along line II-II in Figure 1.Figure 2 shows a cross-sectional view taken along line III-III (the sensor mounting area is shown).This is an enlarged cross-sectional view showing the sliding structure of the exhaust pipe.This is a cross-sectional view along the line V-V in Figure 2.Figure 6 is a cross-sectional view taken along the line VI-VI in Figure 5. The following describes preferred embodiments of the present invention in detail with reference to the drawings. Figure 1 is a right side view of a motorcycle 1 equipped with the exhaust system 30 according to this embodiment. The motorcycle 1 is a scooter-type saddle-riding vehicle having a low-floor step floor 19 where the driver places their feet between the steering handle 9 and the seat 10. At the front end of the vehicle frame, a pair of front forks 2 are supported, pivotally supporting the front wheel WF. A front fender 3 is attached to the front forks 2, which are steered by the steering handle 9, covering the upper part of the front wheel WF. A pair of rearview mirrors 8 are mounted on the upper part of the handle cover 7 that covers the steering handle 9. The upper part of the front forks 2 is covered by a pair of side cowls 4. A front cowl 5, supporting the headlight 6, is connected to the front of the side cowls 4. A leg shield 20, facing the driver's legs, is connected to the rear of the side cowls 4. The unit-swing type power unit P, located behind the undercowl 18, is pivotally supported on the vehicle frame covered by the undercowl 18. The rear wheel WR, which acts as the drive wheel, is pivotally supported at the rear of the power unit P. The power unit P is suspended from the vehicle frame by a rear cushion 15 at a rearward position. A center stand 17 is pivotally supported at the bottom of the power unit P. The power unit P, which includes an internal combustion engine, is fitted with an exhaust system 30 having an exhaust pipe 30 connected to the cylinder head of the internal combustion engine and a muffler 32 acting as a silencer. A muffler cover 12 is fitted to the top of the muffler 32. A grab bar 13 and a taillight device 14 are fitted to the rear of a pair of left and right rear cowls 11 that support the seat 10, and a rear fender 16 is positioned below the taillight device 14. Figure 2 is a cross-sectional view taken along line II-II of Figure 1. Figure 3 is a cross-sectional view taken along line III-III of Figure 2 (the sensor mounting portion is shown). The muffler 32 of the exhaust system 30 houses a catalytic converter C for purifying exhaust gas G. The muffler 32 has a tapered connecting pipe 46 connected to the rear of the exhaust pipe 31, a cylindrical section 49 connected to the rear of the connecting pipe 46, a tapered muffler front section 33 connected to the rear of the cylindrical section 49, a muffler outer shell 39 connected to the rear of the muffler front section 33, and a muffler rear section 48 connected to the rear of the muffler outer shell 39. The inner wall of the muffler outer shell 39 supports the muffler inner shell 38 via multiple buffer members 47, and the inner wall of the muffler inner shell 38 supports the first partition wall 42 and the second partition wall 44. The first partition wall 42 and the second partition wall 44 support a housing 41 that houses a catalytic converter C for purifying exhaust gas G and is connected to the rear of the cylindrical portion 49, an exhaust pipe 50 supported at the rear of the housing 41, a perforated pipe 35 with numerous through holes to enhance sound dampening, an air supply pipe 37 that sends exhaust gas G to the rear from an expansion chamber formed in front of the perforated pipe 35, and an exhaust port pipe 40 connected to the rear of the air supply pipe 37 to form the exhaust port. The muffler casing 39 is provided with mounting holes 60 for attaching an exhaust gas sensor 64 (see Figure 6) that detects the components of the exhaust gas G. The boss 63, where the mounting holes 60 are formed, is supported by a support plate 61, and a connecting plate 65 for attaching the support plate 61 to the casing 39 is connected to the outer circumference of the support plate 61. The exhaust