Air-intake duct and motorcycle comprising the same

1. An air-intake duct through which air taken in from outside is guided to an air flow rate control device configured to control an amount of air flow that is supplied to an engine of a vehicle, the air-intake duct comprising:

a pipe-shaped portion that is coupled to the flow rate control device and has an air-intake passage formed therein;

a chamber portion that is located upstream of the air-intake passage of the pipe-shaped portion in the air flow and has an inner diameter larger than an inner diameter of the pipe-shaped portion; and

an extended pipe-shaped portion configured to extend continuously from the pipe-shaped portion so as to protrude into an inner space of the chamber portion, the extended pipe-shaped portion forming an extended passage connected to the air-intake passage of the pipe-shaped portion;

wherein the chamber portion is continuous with and integral with the pipe-shaped portion, and an inlet end portion of the chamber portion is connected to an air outlet of an air cleaner element.

2. The air-intake duct according to claim 1 ,

wherein the extended pipe-shaped portion is of a funnel-shape that increases in diameter toward an opening end thereof.

3. The air-intake duct according to claim 2 ,

wherein a part of the extended pipe-shaped portion is continuous with an inner surface of the chamber portion.

4. The air-intake duct according to claim 1 ,

wherein a rib is provided between an inner surface of the chamber portion and an outer surface of the extended pipe-shaped portion.

5. An air-intake duct through which air taken in from outside is guided to an air flow rate control device configured to control an amount of air flow that is supplied to an engine of a vehicle, the air-intake duct comprising:

a pipe-shaped portion that is coupled to the flow rate control device and has an air-intake passage formed therein;

a chamber portion that is located upstream of the air-intake passage of the pipe-shaped portion in the air flow and has an inner diameter larger than an inner diameter of the pipe-shaped portion; and

an extended pipe-shaped portion configured to extend continuously from the pipe-shaped portion so as to protrude into an inner space of the chamber portion, the extended pipe-shaped portion forming an extended passage connected to the air-intake passage of the pipe-shaped portion;

wherein the pipe-shaped portion has a second air-intake passage that is configured to open in a space formed between the chamber portion and the extended pipe-shaped portion and is connected to the air flow rate control device.

6. An air-intake duct through which air taken in from outside is guided to an air flow rate control device configured to control an amount of air flow that is supplied to an engine of a vehicle, the air-intake duct comprising:

a pipe-shaped portion that is coupled to the flow rate control device and has an air-intake passage formed therein;

a chamber portion that is located upstream of the air-intake passage of the pipe-shaped portion in the air flow and has an inner diameter larger than an inner diameter of the pipe-shaped portion; and

an extended pipe-shaped portion configured to extend continuously from the pipe-shaped portion so as to protrude into an inner space of the chamber portion, the extended pipe-shaped portion forming an extended passage connected to the air-intake passage of the pipe-shaped portion;

wherein the chamber portion is continuous with and integral with the pipe-shaped portion and an inlet end portion of the chamber portion is connected to an air outlet of an air cleaner box that accommodates an air cleaner element.

7. A motorcycle comprising an air-intake duct coupling a flow rate control device to an air cleaner to allow air taken in from outside to be guided from the air cleaner to the air flow control device, the air flow control device being configured to control an amount of air flow that is supplied to an engine, the air-intake duct including:

a pipe-shaped portion that is coupled to the flow rate control device and has an air-intake passage formed therein;

a chamber portion that is located upstream of the air-intake passage of the pipe-shaped portion in the air flow and has an inner diameter larger than an inner diameter of the pipe-shaped portion; and

an extended pipe-shaped portion configured to extend continuously from the pipe-shaped portion so as to protrude into an inner space of the chamber portion, the extended pipe-shaped portion forming an extended passage connected to the air-intake passage of the pipe-shaped portion;

wherein the chamber portion is configured to open in a direction in which the extended pipe-shaped portion protrudes, and the air taken in from outside flows in the chamber portion and the extended pipe-shaped portion such that the air is guided substantially along a passage axis of the chamber portion and the extended pipe-shaped portion; and

wherein the air-intake duct is formed as a unitary one-piece component made of flexible material.

8. A motorcycle comprising an air-intake duct coupling a flow rate control device to an air cleaner to allow air taken in from outside to be guided from the air cleaner to the air flow control device, the air flow control device being configured to control an amount of air flow that is supplied to an engine, the air-intake duct including:

a pipe-shaped portion that is coupled to the flow rate control device and has an air-intake passage formed therein;

a chamber portion that is located upstream of the air-intake passage of the pipe-shaped portion in the air flow and has an inner diameter larger than an inner diameter of the pipe-shaped portion; and

an extended pipe-shaped portion configured to extend continuously from the pipe-shaped portion so as to protrude into an inner space of the chamber portion, the extended pipe-shaped portion forming an extended passage connected to the air-intake passage of the pipe-shaped portion;

wherein the chamber portion is configured to open in a direction in which the extended pipe-shaped portion protrudes, and the air taken in from outside flows in the chamber portion and the extended pipe-shaped portion such that the air is guided substantially along a passage axis of the chamber portion and the extended pipe-shaped portion; and

wherein the chamber portion is continuous with and integral with the pipe-shaped portion, and an inlet end portion of the chamber portion is connected to an air outlet of an air cleaner element.

9. The motorcycle according to claim 8 ,

wherein the extended pipe-shaped portion is of a funnel-shape that increases in diameter toward an opening end thereof.

10. The motorcycle according to claim 9 ,

wherein a part of the extended pipe-shaped portion is continuous with an inner surface of the chamber portion.

11. The motorcycle according to claim 8 ,

wherein a rib is provided between an inner surface of the chamber portion and an outer surface of the extended pipe-shaped portion.

12. A motorcycle comprising an air-intake duct coupling a flow rate control device to an air cleaner to allow air taken in from outside to be guided from the air cleaner to the air flow control device, the air flow control device being configured to control an amount of air flow that is supplied to an engine, the air-intake duct including:

a pipe-shaped portion that is coupled to the flow rate control device and has an air-intake passage formed therein;

a chamber portion that is located upstream of the air-intake passage of the pipe-shaped portion in the air flow and has an inner diameter larger than an inner diameter of the pipe-shaped portion; and

an extended pipe-shaped portion configured to extend continuously from the pipe-shaped portion so as to protrude into an inner space of the chamber portion, the extended pipe-shaped portion forming an extended passage connected to the air-intake passage of the pipe-shaped portion;

wherein the pipe-shaped portion has a second air-intake passage that is configured to open in a space formed between the chamber portion and the extended pipe-shaped portion and is connected to the air flow rate control device; and

wherein the chamber portion is configured to open in a direction in which the extended pipe-shaped portion protrudes, and the air taken in from outside flows in the chamber portion and the extended pipe-shaped portion such that the air is guided substantially along a passage axis of the chamber portion and the extended pipe-shaped portion.

13. A motorcycle comprising an air-intake duct coupling a flow rate control device to an air cleaner to allow air taken in from outside to be guided from the air cleaner to the air flow control device, the air flow control device being configured to control an amount of air flow that is supplied to an engine, the air-intake duct including:

a pipe-shaped portion that is coupled to the flow rate control device and has an air-intake passage formed therein;

a chamber portion that is located upstream of the air-intake passage of the pipe-shaped portion in the air flow and has an inner diameter larger than an inner diameter of the pipe-shaped portion; and

an extended pipe-shaped portion configured to extend continuously from the pipe-shaped portion so as to protrude into an inner space of the chamber portion, the extended pipe-shaped portion forming an extended passage connected to the air-intake passage of the pipe-shaped portion;

wherein the chamber portion is configured to open in a direction in which the extended pipe-shaped portion protrudes, and the air taken in from outside flows in the chamber portion and the extended pipe-shaped portion such that the air is guided substantially along a passage axis of the chamber portion and the extended pipe-shaped portion; and

wherein the chamber portion is continuous with and integral with the pipe-shaped portion and an inlet end portion of the chamber portion is connected to an air outlet of an air cleaner box that accommodates an air cleaner element.

14. An air-intake duct through which air taken in from outside is guided to an air flow rate control device configured to control an amount of air flow that is supplied to an engine of a vehicle, the air-intake duct comprising:

a pipe-shaped portion that is coupled to the flow rate control device and has an air-intake passage formed therein;

a chamber portion that is located upstream of the air-intake passage of the pipe-shaped portion in the air flow and has an inner diameter larger than an inner diameter of the pipe-shaped portion; and

an extended pipe-shaped portion configured to extend continuously from the pipe-shaped portion so as to protrude into an inner space of the chamber portion, the extended pipe-shaped portion forming an extended passage connected to the air-intake passage of the pipe-shaped portion;

wherein the air-intake duct is formed of a unitary one piece made of flexible material.

15. An air-intake duct through which air taken in from outside is guided to an air flow rate control device configured to control an amount of air flow that is supplied to an engine of a vehicle, the air-intake duct comprising:

a pipe-shaped portion that is coupled to the flow rate control device and has an air-intake passage formed therein;

a chamber portion that is located upstream of the air-intake passage of the pipe-shaped portion in the air flow and has an inner diameter larger than an inner diameter of the pipe-shaped portion; and

an extended pipe-shaped portion configured to extend continuously from the pipe-shaped portion so as to protrude into an inner space of the chamber portion, the extended pipe-shaped portion forming an extended passage connected to the air-intake passage of the pipe-shaped portion;

wherein the chamber portion is configured to open in a direction in which the extended pipe-shaped portion protrudes, and the air taken in from outside flows in the chamber portion and the extended pipe-shaped portion such that the air is guided substantially along a passage axis of the chamber portion and the extended pipe-shaped portion; and

wherein the air-intake duct is formed of a unitary one piece made of flexible material.