JPH0141667Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to the arrangement of intake system members such as carburetors and air cleaners for motorcycles employing swing type power units.

(Prior art) Conventionally, an engine and a case housing the power transmission mechanism of the engine are integrated to form a power unit, and the front end of the power unit is pivotably supported relative to the vehicle body, and the power unit is configured. There is a motorcycle whose rear wheel is rotatably supported in a case.

In general, for motorcycles, one way to improve the engine's intake efficiency is to arrange intake system members such as the manifold, carburetor, and air cleaner upstream of the engine in a straight line to reduce intake resistance. It is also known to utilize intake inertia.

Therefore, even in a motorcycle employing a swing type power unit, in order to improve the intake efficiency, the intake system members may be arranged as described above.

(Problem that the invention aims to solve) However, when adopting a swing type power unit, the power unit must be installed in a space within the body cover in a position that does not interfere with the rear wheels, which inevitably necessitates interference with intake system members. There are also restrictions on where they can be placed.

That is, when placing the carburetor behind the engine, the rear wheels and the rear surface of the engine are close to each other, so the carburetor must be placed offset to the side, causing the manifold to bend. There is a disadvantage that the intake resistance is large.

Furthermore, when the carburetor is placed on the side of the engine, the power unit becomes wider, and in order to prevent interference between the power unit and the vehicle body, the vehicle body must necessarily be made larger.

Furthermore, when placing the carburetor in front of the engine, intake system members such as the carburetor and air cleaner can be arranged in a straight line without bending the manifold to reduce intake resistance. As a result, the air cleaner moves away from the center of swing of the power unit, and as the power unit swings, the air cleaner moves up and down significantly. Therefore, the storage space for the power unit must be increased, which leads to an increase in the size of the vehicle body.

Therefore, it is conceivable to place the air cleaner in a dead space above the case that houses the power transmission mechanism that makes up the power unit, but if this arrangement is used, the intake pipe connecting the air cleaner and the carburetor will be placed in the middle. This has the disadvantage that it bends at some points, increasing the intake resistance. Furthermore, in order to reduce the intake resistance, it is possible to increase the diameter of the intake pipe, but this is subject to space constraints.

As described above, when a swing type power unit is employed, some inconvenience occurs in the arrangement of intake system members.

(Means for solving the problem) In order to solve the above problem, the present invention is based on the premise that a carburetor is placed in front of the engine, and an air chamber is placed in front of this carburetor, and the power unit is also configured. Each air cleaner was placed in a dead space on the case housing the power transmission mechanism, and the front of the air cleaner was connected to the rear of the air chamber, and the rear of the air chamber and the front of the carburetor were connected by communication pipes.

(Example) An example of the present invention will be described below based on the accompanying drawings.

Fig. 1 is a plan view of a swing type power unit according to the present invention, Fig. 2 is a side view of the swing type power unit, and Fig. 3 is a side view of a scooter type motorcycle to which the swing type power unit is applied. FIG. 4 is a rear view of the motorcycle.

First, the overall structure of the motorcycle will be explained based on FIGS. 3 and 4.

The motorcycle 1 is equipped with a low step floor 2, a leg shield 3 integrally stands upward from the front end of the step floor 2, and a front cover 5 that covers the upper part of the front wheel 4 is integrally formed in front of the leg shield 3. Installed. Further, the leg shield 3 covers the head pipe from behind, and a handle 6 is fixed to the head pipe.
Back mirrors 7, 7 are attached to both sides of the vehicle.

On the other hand, both sides of the lower part of the seat 8 are covered with side covers 9, and the side covers 9 cover the vehicle body frame 10.
(See Figures 3 and 4). and,
A power unit 11 is arranged in the space surrounded by the side cover 9, and the front end of the power unit 11 is swingably supported with respect to the vehicle body frame 10 via a link member 11a. The rear wheel 12 is rotatably supported by the
Furthermore, the rear part of the power unit 11 and the vehicle body frame 10
A rear assembly 13 is installed between the two.

Next, the structure of the power unit 11 will be explained in detail based on FIGS. 1 and 2.

The power unit 11 is an upright engine 14
and a case 15 that houses a power transmission mechanism for transmitting the power of the engine 14 to the rear wheels.A carburetor 17 is provided in front of the engine 14 via an intake pipe 16, and a carburetor 17 is provided at the front of the engine 14, and a A drive shaft 18 protrudes inward from the end, and an air cleaner 19 is further fixed on the case 15.

An air chamber 20 is arranged in the space inside the side cover 9 in front of the power unit 11, and a pipe 19a protrudes from the rear surface of the air chamber 20 and the front surface of the air cleaner 19.
are connected by a communication pipe 21 such as a cone tube, and the rear surface of the air chamber 20 and the front surface of the vaporizer 17 are also connected by a communication pipe 22 such as a cone tube.

The outside air purified by the air cleaner 19 enters the air chamber 20 through the communication pipe 21, and the air in this air chamber 20 is introduced into the carburetor 17 through the communication pipe 22, where it is used as an intake air. It is supplied to the engine 14 through a pipe 16. Here, since the air chamber 20 has a large capacity, the intake resistance within the air chamber 20 is extremely small, and as a result, the same effect as that of arranging the air cleaner 19 and the carburetor 17 in a straight line can be obtained. Demonstrate.

(Effects of the invention) As explained above, according to the invention, in a motorcycle employing a swing type power unit, an air chamber is placed in front of the power unit, while a carburetor is placed in front of the upright engine. In addition, an air cleaner is placed in the dead space above the power transmission case that makes up the power unit, and the air cleaner and carburetor are connected via an air chamber. The same effect as when the system members are arranged in a straight line can be achieved, and as a result, the intake efficiency can be improved.

[Brief explanation of the drawing]

Fig. 1 is a plan view of a swing type power unit according to the present invention, Fig. 2 is a side view of the swing type power unit, and Fig. 3 is a side view of a scooter type motorcycle to which the swing type power unit is applied. FIG. 4 is a rear view of the motorcycle. In addition, in the drawing, 9 is a side cover, 10 is a vehicle frame, 11 is a power unit, 14 is an engine,
15 is a case housing the power transmission mechanism, 16 is an intake pipe, 17 is a carburetor, 19 is an air cleaner, 2
0 is an air chamber, and 21 and 22 are communication pipes.

Claims (1)

[Scope of utility model registration request] In a motorcycle in which an upright engine and a case housing a power transmission mechanism for transmitting the power of the engine to the rear wheels are integrated to form a power unit, and this power unit is swingably suspended on the vehicle body, the engine is An air chamber is disposed in front, an air cleaner is disposed above the case housing the power transmission mechanism, and a carburetor is disposed in front of the engine via an intake pipe. A swing-type power unit for a motorcycle, which is characterized by being connected to the front side by a communicating tube such as a cone tube.