Air intake structure for motorcycle

• US 20050051375A1
• Filed: 08/19/2004
• Published: 03/10/2005
• Est. Priority Date: 09/09/2003
• Status: Active Grant

• Current Assignee: Kawasaki Jukogyo Kabushiki Kaisha
• Original Assignee: Kawasaki Jukogyo Kabushiki Kaisha
• Inventors: Momosaki, Makoto
• Granted Patent: US 7,380,624 B2
• Time in Patent Office: Days
• US Class Current: 180/219
• CPC Class Codes: B62J 40/10 characterised by air duct arrangements
• CPC Class Codes: F02M 35/02 Air cleaners
• CPC Class Codes: F02M 35/10013 Means upstream of the air filter; Connection to the ambient air
• CPC Class Codes: F02M 35/10118 with variable cross-sections of intake ducts along their length; Venturis; Diffusers
• CPC Class Codes: F02M 35/10262 Flow guides, obstructions, deflectors or the like for generating a charge motion in the cylinder F02B31/00; for re-atomising condensed fuel or homogenising fuel-air mixture F02M29/00
• CPC Class Codes: F02M 35/162 Motorcycles; All-terrain vehicles, e.g. quads, snowmobiles; Small vehicles, e.g. forklifts
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

An air intake structure is incorporated into a motorcycle having a body frame including a hollow head member provided in its front wall with an air inlet opening and supporting a steering shaft having an upper end holding a handlebar, and paired, right and left hollow main frame members extending rearward from the head member on right and left sides, respectively, of the motorcycle. The air intake structure includes an air cleaner disposed behind the head member, an inlet duct having an open front end opening forward, and an open rear end connected to the air inlet opening of the head member, an intake duct inserted in the hollow main frame member, respectively having a front part extended toward the head member in the hollow main frame member and having an open front end, and a rear part connected to the air cleaner. An air passage defined by the intake duct has a sectional area increased downstream with respect to the direction of air flow. The intake duct are internally provided with straightening plate, respectively.

Claims

1. An air intake structure for a motorcycle having a body frame including a hollow head member provided in its front wall with an air inlet opening and supporting a steering shaft having an upper end holding a handlebar, and paired, right and left hollow main frame members extending rearward from the head member on right and left sides, respectively, of the motorcycle, said air intake structure comprising:

an air cleaner disposed behind the head member;

an inlet duct having an open front end opening forward, and an open rear end connected to the air inlet opening of the head member;

an intake duct inserted in the hollow main frame member, having a front part extended toward the head member in the hollow main frame member and having an open front end, and a rear part connected to the air cleaner.

2. The air intake structure according to claim 1, wherein the number of the intake duct is two, one of the two intake ducts is inserted in the right main frame member, and the other intake duct is inserted in the left main frame member.

3. The air intake structure according to claim 2, wherein an air passage defined by each of the intake duct has a cross sectional area increased downstream with respect to the direction of air flow.

4. The air intake structure according to claim 2, wherein the intake ducts have bends bending in a horizontal plane, respectively.

5. The air intake structure according to claim 2, wherein the intake ducts are internally provided with straightening plates for fairing air flow inside the intake ducts, respectively.

6. The air intake structure according to claim 2, wherein the air cleaner has an air cleaner box containing a forward convex V-shaped air cleaner element.

7. The air intake structure according to claim 2, wherein a head pipe for supporting the steering shaft is included in the hollow head member, and the open front end of the intake duct is opening near the head pipe.