JPS6288689A - Outside-air introducing structure in motorcycle - 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 a structure for introducing outside air into a carburetor for supplying a mixture to an engine in a motorcycle, and in particular to a structure for introducing outside air into a carburetor for supplying a mixture to an engine in a motorcycle. This invention relates to a new outside air introduction structure that forms an introduction path for the outside air.

(Prior Art) In an internal combustion engine, outside air is introduced into a carburetor through an air cleaner, where it is mixed with fuel, such as gasoline, and an air-fuel mixture is supplied into the cylinder.

[Problem that the invention seeks to solve]

In this case, in motorcycles, the carburetor and air cleaner, which are generally located behind the engine, may be difficult to directly introduce outside air into the air cleaner because other auxiliary equipment is attached to the carburetor and air cleaner. It is necessary to separately form an introduction path such as a duct to supply fresh air to the air cleaner.

Against this background, the present invention attempts to develop a rational outside air introduction structure by skillfully utilizing the body structure of this type of motorcycle.

[Means for solving problems]

That is, the outside air introduction structure in the motorcycle according to the present invention is as follows:
It has a backbone-shaped main pipe connected to the steering head, and a pair of left and right down tubes formed to rotate downward from the steering head in front of the engine, and the steering head, the main pipe, and the down tube each include: In a motorcycle body reinforced by a gusset, the gusset has at least a front gusset that fixes the steering head and the two downtubes, and a side gusset that fixes the steering head, the main pipe, and the downtube. However, these front and side gussets and mm plates closing near the rear ends of the left and right side gussets form an intake chamber with an opening provided only below between the down tubes at the rear of the steering head. This device is characterized by having an outside air introduction hole formed in the main pipe facing the room, thereby achieving the above-mentioned objective.

〔Example〕

Hereinafter, the present invention will be specifically explained based on illustrated embodiments. Reference numeral 1 denotes a motorcycle to which the present invention is applied, and the outside air introduction structure of the present invention is formed near a steering head 2, which is a connecting portion of a front fork.

To explain the surrounding parts of the steering head 2, a backbone-shaped hollow main pipe 4 is arranged so as to pass above the engine 5 so that the rear part is slightly lower than the head vibe 3.
A pair of left and right down tubes 6 that go around the front and extend downward
to be placed. In order to reinforce these, a front gusset 7 is provided to integrally reinforce the head vibe 3 and the two down tubes 6, and a side gusset 8 is provided to connect the head vibe 3, main pipe 4, and down tube 6. will be established. If further strength is required, the rear gusset 9, which is an rfI chain plate and serves as a strength member, is connected along the rear edge of the side gusset 8.

If no reinforcement is required for the rear gazette 9, it may be a mere closing plate that does not function as a reinforcing member.

With this configuration, the head vibe 3, main pipe 4. Down tube 6, front gusset 7, side gusset 8. An intake chamber 10 is formed substantially at the rear of the steering head 2 by the rear gusset 9, and an opening 11 is formed in this intake chamber 10 only in the lower part between the down tubes 6. An introduction hole 12 is opened below the main pipe 4 facing the intake chamber 10. The main pipe 4 in which the introduction hole 12 is formed further has a frontage at its rear end and is connected to a duct 13, and the other end of the duct 13 is connected to the air cleaner 13. Furthermore, a center pipe 15 is connected downwardly to the main pipe 4 at a position slightly forward of the rear end, and preferably the main pipe 4 and the center pipe 15 are connected to each other.
and the lower part of the center pipe 15 is opened.

Therefore, the outside air A is sucked in from the lower opening 11 of the intake chamber 10 as shown by the arrow in the figure, enters the intake chamber 10, and from there passes through the introduction hole 12 of the main pipe 4 into the main pipe 4.
It is further introduced into the air cleaner 14 from the rear end via the duct 13. At this time, it is expected that the outside air is mixed with relatively large particles of sand, muddy water, etc., but in this case, in this embodiment, the center pipe is placed slightly forward of the rear end of the main pipe 4. Since the pipe 15 is in communication with the center pipe 15, such materials are discharged to the outside from the lower opening through the center pipe 15.

〔Effect of the invention〕

As described above, the present invention covers the steering head, main pipe, and down tube with a gusset to form a path for introducing outside air into the air cleaner from the opening between the down tubes. There is no need to add a mechanism, and this structure can be easily configured. Further, since there is no need to form special openings in the gazette etc. for introducing outside air, the strength of the gazette itself is not impaired by the openings, and a thinner and lighter gazette can be used.

[Brief explanation of drawings]

FIG. 1 is a side view showing a motorcycle to which the present invention is applied, FIG. 2 is a side view of the present invention, and FIG. 3 is a sectional view taken along FIG. 2 - ■. 1... Motorcycle 2... Steering head 3
...Head pipe 4...Main pipe 6.
・・Down tube 7・Front gazette 8・
...Side gusset 9...Back gusset serving as a closing plate 10...Intake chamber 11...Opening 12...Introduction hole 13...Duct 14...Air cleaner
15...Center pipe

Claims (1)

[Claims] 1. It has a backbone-shaped main pipe connected to the steering head, and a pair of left and right down tubes formed to rotate downward from the steering head in front of the engine, and the steering head, the main pipe, and the down tube are connected to each other. Each of the above is a motorcycle body reinforced with gussets, the gussets being at least a front gusset that fixes between a steering head and two down tubes, and a side gusset that fixes a steering head, a main pipe, and a down tube. These front and side gussets and closing plates that close near the rear ends of the left and right side gussets form an intake chamber at the rear of the steering head that has an opening only below between the down tubes, and further An outside air introduction structure for a motorcycle, characterized in that an outside air introduction hole is formed in the main pipe facing the intake chamber.