JPH0657546B2 - Motorcycle - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an intake passage of an engine in a motorcycle.

(Prior Art) In a motorcycle in which a swingable power unit is pivotally supported at a lower portion of a vehicle body, a frame member of the vehicle body and a power unit are vertically spaced apart from each other, as seen in JP-A-57-114769. A carburetor and an air cleaner are attached above the power unit.

(Problems to be Solved by the Invention) As described above, in the case where the air cleaner case is provided as the carburetor in the upper part of the engine, a space for the swing stroke of the power unit is provided between these parts and the rear frame. The air cleaner case is particularly bulky, and the connection tube from the air cleaner case to the carburetor must be placed above the power unit, so the space under the rear frame is narrowed and the ground clearance of the power unit is reduced. If it is taken sufficiently, there is a problem that it becomes difficult to arrange the fuel tank and other parts. An object of the present invention is to solve this problem.

(Means for Solving the Problem) According to the means for solving the problem in the present invention, a power unit is configured by integrally providing a mission case at a rear portion of an engine portion with a cylinder center line in the front-rear direction, and a front wheel and a rear wheel. In a motorcycle in which the engine unit is located between the power unit and the power unit swingably supported on the vehicle body, an air cleaner case is arranged in front of the mission case in the power unit and on the side of the engine unit, and A continuous carburetor is arranged above the power unit, and an intake pipe from the air cleaner case to the engine via the carburetor is arranged along the upper wall of the power unit from the upper portion of the air cleaner case.

(Operation) With the above configuration, the air cleaner case has almost the same height as that of the power unit, and the carburetor and the intake pipe from the air cleaner case to the engine via the carburetor are arranged above the power unit. Therefore, there is a space in the upper portion. As a result, the power unit can be arranged at the upper position, and the minimum ground clearance can be made a sufficient value.

(Example) Next, this invention is demonstrated about the Example shown in figure. In the drawing
(1) shows a vehicle body or frame having a front wheel (2), a rear wheel (3), and a saddle (4) on the upper side of the intermediate portion, the vehicle body (1) having a shaft support (1a) on the lower side of the intermediate portion, It has a rear fork (1b) consisting of a pair of frame members extending rearward from the shaft supporting portion.
Attach the chain sprocket (7) to the pedal crankshaft (6) that has the pedal arms (5) and (5) at both ends pivotally supported on a),
The rear wheel (3) can be driven through the chain (8) by the rotation of the chain sprocket (7), and further below the shaft support (1a) of the crankshaft (6) of the vehicle body (1). Both pedal arms
(5) A power unit (9) that is located in the arrangement gap of (5) and extends rearward is mounted, and the rear wheel (3) is mounted by the power unit (9).
As a whole, a motorcycle equipped with a pedal was constructed.

To explain this in more detail, the power unit (9) is
As shown in the figure, turn the cylinder part (9a) forward and
Using a horizontal vertical two-cycle engine with (9b) arranged rearward, a rearward transmission case (9c) incorporating a planetary reduction gear (10) is attached to the side surface of the crankcase (9b), At the rear end of the mission case (9c),
Output shaft (11) protruding into the rear space of the crankcase (9b)
Is supported by a drive roller (12) facing the rear wheel (3), and the power unit (9) is housed in the gap between the pedal arms (5) and (5). At the front part of the pedal crankshaft (6) by means of hanger bolts (13) juxtaposed below the shaft support (1a) of the pedal crankshaft (6) so that it can swing in the vertical direction, and its rear part is a wire-operated lifting machine (14). When the power unit (9) is swung upward by operating the hoisting machine (14), the drive roller (12) is brought into pressure contact with the tire surface of the rear wheel (3) and the power unit (9). 9) The rear wheel
The drive of (3) is given.

In the drawing, (15) shows an air cleaner case attached to the side surface of the cylinder portion (9a) of the power unit (9), and is attached to the space formed by the step between the side surface and the side surface of the crank case (9b). The air cleaner case (15) is
(9a) has a total height, a front-rear length, and a lateral width smaller than those of (9a), and has the same minimum ground clearance and maximum upper surface position as those of the cylinder portion (9a). A cleaner element (15A) is housed inside in parallel with the side wall of the cylinder (9a) .The air cleaner case (15) has an air inlet (15a) at the lower inside surface and an air outlet at the opposite side of the air inlet (15a). (15b)
And forming a connection tube (16) from the air outlet (15b)
The intake port (1) formed in the crankcase (9b) of the power unit (9) through the carburetor (17) and the intake pipe (18).
An intake passage leading to 9) was constructed, and the intake pipes such as the connection tube (16) and the intake pipe (18) were arranged along the upper surface of the power unit.

Here, according to the present invention, the carburetor (17) is provided with, for example, the connection tube (16) and the intake pipe (18) in the power unit.
The rear fork (1) is supported by (9) and is arranged at a position facing between the rear forks (1b) (1b) as a pair of left and right frame members extending rearward from the shaft support (1a) above the middle part thereof. 1
b) The carburetor (17) can be moved up and down between (1b), so that even if the minimum ground height of the power unit (9) is set to be relatively high, it is possible The carburetor (17) does not move up and down between the rear forks (1b) (1b) to cause interference with the vehicle body (1).

Further, in the figure, the lower half of the carburetor (17) is housed in the space formed by the step between the crankcase (9b) and the mission case (9c) of the power unit (9), and the carburetor is vaporized. Enclosed from above and below with the arrangement part of the device (17), the rear forks (1b) (1b) and the crankcase (9b), and from the left and right with the transmission case (9c) and the rear wheel drive chain (8). By enclosing the carburetor (17), the function of guarding against external matters is improved.

In the drawing, (20) shows a control box for a starting intake system, that is, a by-starter, which is attached to the cylinder portion (9a) of the power unit (9) so as to be interposed between the air cleaner case (15) and the air cleaner case (15). One of the pair of air outlets (15c) (15c) for the by-starter formed on the one side is the secondary air inlet (20a) of the box (20), and the other is the air-fuel mixture for the by-starter of the carburetor (17). The box (20) through the generator (17a)
The air-fuel mixture inlet (17b) of the
The outlet (20c) of (20) is connected to the intake pipe (8) side, and the control valve (20e) interlocking with the bimetal (20d) housed in the box (20) controls the intake air-fuel mixture at engine startup. The concentration is automatically controlled according to the engine temperature.

Drawing (21) is a muffler connected to the exhaust port (22) formed on the lower surface of the cylinder (9a) of the power unit (9) via the exhaust pipe (13), (24) is a rear fender, (25) is a fuel tank,
(26) is an oil tank, (27) is an oil pump provided at the rear of the mission case (9c), (28) and (29) are mission cases.
A ratchet type one-way clutch for starting the engine and a generator provided in (9c), and (30) a chain cover.

As described above, according to the present invention, the carburetor is arranged above the middle portion of the power unit so as to face the pair of left and right rear forks, and the carburetor is surrounded by the rear forks and the power unit from above and below. And effectively protected from foreign objects. When the vertical width of the rear fork (1b) is large or when a vertical reinforcing plate is attached to the rear fork, the carburetor (1
The protected area for 7) is also widened.

Moreover, since the relatively small carburetor (17) and the intake pipe consisting of the connection tube (16) and the intake pipe (18) are only arranged above the power unit (9), the upper vehicle body There is a margin between and, and there is an advantage that the power unit can be arranged with sufficient minimum ground clearance.

(Effect of the Invention) As described above, according to the present invention, the air cleaner case is arranged on the front side of the power unit, the carburetor is arranged on the upper part of the power unit, and the intake pipe communicating these is provided along the upper wall of the power unit. Since it is arranged, the total height of the power unit including the carburetor can be made small, and thereby the power unit can be pivotally supported at a high position with respect to the vehicle body, and the minimum ground clearance can be made sufficiently high. Play.

[Brief description of drawings]

FIG. 1 is a side view of an example of an engine-equipped bicycle to which the device of the present invention is applied, FIG. 2 is a side view of a partial cut of a main part thereof, FIG. 3 is a front view of a partial cut of the main part, and FIG. A partial cutaway plan view of the main part thereof, and FIG. 5 is a cutaway plan view taken along the line VV of FIG. (1) …… Body, (1a) …… Spindle (1b) …… Rear fork (frame member) (2) …… Front wheel, (3) …… Rear wheel (7) …… Chain sprocket, (9) ...... Power unit (12) …… Drive roller, (17) …… Vaporizer

Claims (1)

[Claims] 1. A power unit is constructed by integrally providing a transmission case at a rear portion of an engine portion with a cylinder center line directed in the front-rear direction, and the engine portion is positioned between a front wheel and a rear wheel to mount the power unit on a vehicle body. In a swingably pivoted motorcycle, an air cleaner case is arranged in front of a mission case in a power unit and lateral to an engine section, and a carburetor connected to the engine section is arranged above the power unit. A motorcycle, characterized in that an intake pipe from the air cleaner case to the engine via the carburetor is arranged along the upper wall of the power unit from the upper part of the air cleaner case.