JPS6231575A - Suction system for motorcycle, etc. - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an air intake device for a motorcycle or the like equipped with a resonance device.

[Conventional technology]

BACKGROUND ART In engines mounted on motorcycles, intake noise is generally reduced by an intake device consisting of an air cleaner, an intake pipe, and the like. That is, the intake device is acoustically a kind of low-pass filter, and attenuates sound pressure above a certain frequency.

Incidentally, in recent years, demands for reducing noise in motorcycles of this type have become more severe, and reducing the intake noise has been attracting widespread attention as one of the noise countermeasures. In order to meet this demand, it is conceivable to connect a resonance device to the intake device to reduce intake noise.

[Problem that the invention seeks to solve]

However, such a structure is impractical because it requires housing the resonator in addition to the engine in a very limited space. That is, in order to reduce intake noise with a high contribution rate of low-frequency sound using a resonance device, a resonance box with a large volume is required, and the housing space for the engine must be increased. Therefore, there is a demand for an intake device that can reduce intake noise without increasing the housing space.

[Means for solving problems]

The present invention has been made in response to such demands, and it is an object of the present invention to provide an intake system for motorcycles and the like that can reduce intake noise without increasing the engine housing space. The intake device for a motorcycle or the like according to the present invention has a swing arm formed of a hollow tube connected to an intake passage via a deformable passage member.

[Effect]

In the present invention, the swing arm is used as a resonance device by communicating the inside of the intake passage and the hollow portion of the swing arm.

〔Example〕

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings. Fig. 1 is a sectional view showing an intake device for a motorcycle or the like according to the present invention, and Fig. 2 is a side view showing a motorcycle in which the intake device is implemented. A frame consisting of The frame 1 includes a tank rail 2, a seat pillar tube 3 connected to the rear part of the tank rail 2, a seat rail 5 that supports a seat 4, and the like. A swing arm 6 is formed of a hollow tube and supports a rear end 7 at its rear end, and is located at the lower center of the frame 1 and is swingably supported by a pivot portion 8 provided on the seat pillar tube 3. Although not shown, a cushion unit is interposed between the rear end 7 and the frame 1 to cushion the swing of the rear end 7.

10 is a saddle-shaped fuel tank attached to the tank rail 2. A downwardly extending recessed portion is provided on the lower side of the fuel tank 10, and an air cleaner 11 is housed in the recessed portion. The air cleaner 11 consists of an upper case Ila holding an element and a lower case Ilb forming a chamber downstream of the element.
extends above the swing arm 6 along the tank rail 2, and a connecting portion 12 connected to a carburetor, which will be described later, is provided toward the front at a portion intervening between the left and right tank rails 2. ing. An engine 15 is housed in a limited housing space below the fuel tank 10, and a carburetor 16 is connected to the rear side of the cylinder head. This carburetor 16 and the air cleaner 11 form an intake passage that supplies outside air to the engine 15. 17 is a resin cowling that covers the front part of the motorcycle.

The swing arm 6 has a rectangular cross-section and is formed relatively large in order to obtain necessary rigidity without increasing weight. Therefore, an attempt is made to increase the internal volume of the swing arm 6. To be more specific, the swing arm 6 consists of a pair of left and right arm parts 6a, 6a that extend to the sides of the rear wheel 7, and a connecting part 6b that connects them. In order to obtain strength in the direction of movement, the connecting portion 6b is made rectangular and long in the vertical direction.
The cross section of is a horizontally long rectangle.

6C is a pivot hole provided in the front end in the vehicle width direction, and 6d is a rear wheel support hole provided in the rear end.

A flexible hose 20 serves as a deformable passage member that connects the swing arm 6 to the intake passage, and one end is connected to the rear end surface of the lower case Ilb, and the other end is connected to the center of the upper surface of the connecting part 6b. ing.

In the intake device of a motorcycle or the like configured in this way, the inside of the intake passage and the inside of the swing arm 6 are connected by connecting the lower case llb of the air cleaner 11 and the connecting part 6b of the swing arm 6 with the flexible hose 20. It is possible to communicate with the hollow part formed in the. As a result, the intake noise of the engine 15 propagated into the intake passage can be resonated in the hollow portion of the swing arm 6 and attenuated.

Here, the internal volume of the swing arm 6, the flexible hose 20
The cross-sectional area and length of are set to attenuate intake noise at the desired frequency.

Therefore, since the swing arm 6 can be used as a resonance device, the resonance device can be provided in the intake device without adding any special members.

In the above embodiment, an example was described in which the connecting portion 6b of the swing arm 6 was connected to the air cleaner 11 via the flexible hose 20, but the present invention is not limited to this. For example, the swing arm 6 side may be connected to the arm portion 6a, and the intake passage side may be connected to the air cleaner 1.
1 and the vaporizer 16, etc., as appropriate.

In addition to the flexible hose 20, the deformable passage member may also be a bellows member or a pair of arc-shaped pipe members slidably fitted to each other in the swinging direction of the swing arm 6. can.

〔Effect of the invention〕

As explained above, according to the present invention, since the swing arm formed of a hollow tube is connected to the intake passage through the deformable passage member, the inside of the intake passage and the hollow part of the swing arm are communicated with each other. , the swing arm can be used as a resonator.

Therefore, since the resonance device can be provided in the intake device without adding any special members, intake noise can be reduced without increasing the engine housing space.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an air intake device for a motorcycle or the like according to the present invention, and FIG. 2 is a side view showing a motorcycle in which the air intake device is implemented. 3... Seat pillar tube, 6... Swing arm, 11... Air cleaner, 16... Carburetor, 20... Flexible hose. Figure 2

Claims (1)

[Claims] An intake device for a motorcycle, etc., in which a swing arm is formed of a hollow tube, and the swing arm is connected to an intake passage via a deformable passage member.