JPH0631057B2 - Motorcycle - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a mounting portion of a carburetor 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 separated from each other as seen in JP-A-57-114769. The power unit and the carburetor provided above the power unit are mounted with their side surfaces open to the side of the vehicle body.

(Problems to be Solved by the Invention) In the above motorcycle, the carburetor having a relatively low strength and the pipes connected to the carburetor are opened to the side and external objects from the side and diagonally rearward. To be reckless,
At least these portions are preferably covered with a protective member.

However, it is an object of the present invention to obtain a structure capable of protecting the vaporizer portion without using the above-mentioned protective member.

(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 the motorcycle in which the engine unit is positioned between the and the power unit is pivotally supported on the vehicle body frame,
The carburetor connected to the engine unit is attached to the upper part of the power unit between the left and right frame members extending substantially horizontally of the vehicle body frame.

(Operation) Since the present invention is provided with the above configuration, since the frame members on both the left and right sides cross diagonally rearward from the side surfaces of the carburetor and the pipes connected to the carburetor, the frame members serve as protective frames for these members. To work.

(Example) Next, this invention is demonstrated about the Example shown in figure. In the drawing
(1) shows a vehicle body 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 frame (1) having a shaft support (1a) on the lower side of the intermediate portion, A pedal crankshaft (6) having a rear fork (1b) consisting of a pair of frame members extending rearward from the shaft support portion and having pedal arms (5) (5) at both ends pivotally supported by the shaft support portion (1a). Attach the chain sprocket (7) and rotate the chain sprocket (7) to rotate the chain.
The rear wheel (3) can be driven via (8), and
A power unit (9), which is located in the gap between the pedal arms (5) and (5) and extends rearward, is mounted on the lower side of the shaft support (1a) of the crankshaft (6) of (1). From (9) the rear wheel
(3) was made freely drivable to construct a motorcycle with a pedal as a whole.

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) .The air cleaner case (15) has an air inlet (15a) on the lower side of the inner side surface and an upper side thereof. Forming an air outlet (15b),
(15b) to connection tube (16), carburetor (17) and intake pipe
(18) via the crankcase of the power unit (9)
An intake system path leading to the intake port (19) formed in (9b) was constructed.

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 illustration, the lower half of the carburetor (17) is connected to the crankcase (9b) of the power unit (9) and the mission case.
(9c) is housed in the space formed by the step between the carburetor (17) and the rear fork (1b) (1b) and the crankcase (9b) from above and below, while The transmission case (9c) and the rear wheel drive chain (8) are surrounded from the left and right to improve the guard function of the carburetor (17) against external objects.

In the drawing, (20) shows a by-starter, that is, a control box for a starting intake system, 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 a pair of air outlets (15c) (15c) for the by-starter formed in the box (20)
The secondary air introduction port (20a) and the other side are connected to the box (2) via the gas mixture generating part (17a) for the by-starter of the vaporizer (17).
(0) is connected to the air-fuel mixture inlet (17b), the outlet (20c) of the box (20) is connected to the intake pipe (18) side, and the bimetal (20d is housed in the box (20). The control valve (20e) interlocked with (1) automatically controls the concentration of the intake air-fuel mixture at engine startup according to the engine temperature.

In the drawing, (21) is a muffler connected to the exhaust port (22) formed on the lower surface of the cylinder part (9a) of the power unit (9) through the exhaust pipe (23), (24) is a rear fender, and (25) is a fuel tank. , (26) is an oil tank, (27) is a mission case (9c)
An oil pump provided at the rear part, (28) and (29) are ratchet type one-way clutches and generators for starting the engine provided in the mission case (9c), and (30) is 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 reinforcing plate is attached to the rear fork in the vertical direction, the protection area for the carburetor (17) is widened. Moreover, since the carburetor swings between the two rear forks when the unit swings upward, interference between the carburetor and the rear fork can be prevented even if the carburetor position is high, and the lowest ground of the unit. It has the effect of ensuring a sufficient height.

(Effects of the Invention) According to the present invention, the carburetor of the power unit pivotally supported on the vehicle body frame as described above is positioned between the left and right frame members extending substantially horizontally of the vehicle body frame.
The carburetor is protected by being blocked from the outside by the frame member. This has the effect of omitting or simplifying the protection means for the carburetor having a relatively low mechanical strength and the pipes connected thereto.

[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 frame (1a) …… Spindle (1b) …… Rear fork (frame member) (2) …… Front wheel (3) …… Rear wheel (7) …… Chain sprocket (9) …… Power unit (12) …… Drive roller (15) …… Air cleaner case (17) …… Vaporizer

Claims (1)

[Claims] Claim: What is claimed is: 1. A transmission unit is integrally provided at a rear portion of an engine portion having a cylinder center line in the front-rear direction to form a power unit, and the engine portion is positioned between front wheels and rear wheels so that the power unit is mounted on the vehicle body frame. In a two-wheeled motorcycle swingably supported by a carburetor, a carburetor connected to the engine section is attached to an upper part of a power unit between left and right frame members extending substantially horizontally of the vehicle body frame. Motorcycle.