JPH01101290A - Scooter type motorcycle - Google Patents

Abstract

PURPOSE: To secure a sufficient space between a crankcase and a seat by tilting a cylinder forward from the front of the crankcase in an approximately horizontal direction, and connecting a carburetor to the front end of an intake pipe connected to the upper part of the front surface of the crankcase. CONSTITUTION: The cylinder 25 of an engine 20 is tilted forward from the front of a crankcase 21 in an approximately horizontal direction, and a carburetor 32 is connected to the front end of a forwardly extending intake pipe 31 connected to the upper part of the front surface of the crankcase 21. Therefore, the carburetor 32 held close to the upper surface of the crankcase 21 can be placed across the crankcase 21 and the cylinder 25. As a result, the position of the carburetor 32 inside a storage space 30 is more forwardly and downwardly biased than before, and the carburetor 32 and the cylinder 25 do not greatly enter the storage space 30. Therefore, the storage space 30 can be widely opened to the space for the positions of a fuel tank 13 and an oil tank 14 and to the storage space for small articles.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a scooter type motorcycle in which a unit swing type power unit is disposed below a seat.

[Conventional technology]

This type of scooter-type motorcycle has a frame that is bent significantly downward between the front fork and the seat, and a flat step is attached to the bent bottom. Further, behind this step, a unit swing type power unit is arranged which extends rearward from one side of an engine and a crankcase of this engine and has a rear wheel at its rear end. This power unit is located just below the seat, and the area around the engine of this power unit and below the seat is completely hidden by a cover.

By the way, the engine of this power unit has conventionally had a cylinder erected upward on the front upper surface of the crankcase, as seen in ``Utility Model Application Publication No. 53-123751''. The carburetor was located at the rear of the cylinder.

[Problem to be solved by the invention]

However, according to this conventional configuration, since the cylinder stands up toward the space below the seat, the carburetor behind the cylinder also largely enters the space, and much of this space is occupied by the cylinder and carburetor. It becomes exclusive. Then, in the case of a scooter type motorcycle,
The space below this seat is the installation space for the fuel tank and other electrical components, as well as the storage space for small items, so there may be restrictions on the placement of the fuel tank, etc., or there may be insufficient storage space. There are problems such as not being able to do it.

Therefore, an object of the present invention is to provide a scooter type motorcycle in which the cylinder and the carburetor do not protrude significantly above the crankcase, and a sufficient space can be secured between the crankcase and the seat.

[Means to solve the problem]

Therefore, in the present invention, a pair of left and right back stays are connected to the rear part of the down tube connected to the head vibe, the rear parts of these back stays are raised upward, and a seat is provided on the upper part of this raised part. The rising part has a swingable pivot for the front end of a unit swing-type power unit, which is composed of an engine and a transmission case that extends rearward from one side of the engine's crankcase and has a rear wheel at its rear end. Assuming that the motor vehicle is a scooter-type motorcycle in which the area around the engine of the power unit and the area below the seat is covered with a cover, the cylinder of the engine is tilted forward approximately horizontally from the front part of the crankcase, and The crankcase is characterized in that an intake pipe extending forward is connected to the front part of the crankcase, and a carburetor is connected to the front end of the intake pipe.

[Effect]

According to this configuration, since the cylinder is tilted forward approximately horizontally, the carburetor can be placed in the space opened above the front end of the crankcase, and the carburetor can be placed further forward than in the past. , and can be placed closer to the bottom. For this reason, the cylinder and carburetor do not fit significantly between the crankcase and the seat, and this space can be widely opened up as a space for installing various components such as a fuel tank or as a space for accommodating small items.

〔Example〕

The present invention will be explained below based on an embodiment shown in the drawings.

Reference numeral 1 in the figure indicates an underbone frame, and a front fork 3 is pivotally supported by a head vibe 2 at the front end of the frame. A downwardly extending down tube 4 is welded to the lower rear surface of the head vibe 2. The lower end of the down tube 4 extends horizontally toward the rear, and left and right backstays 5 extending rearward are welded to the rear end of this extension 4a. Then, on the upper surface of the extension portion 4a of the down tube 4 and the backstay 5,
A flat footrest board 8 is mounted, and this footrest board B is continuous with the leg shield 7 fixed to the head vibe 2 and the down tube 4.

The left and right backstays 5 are raised rearward and diagonally upward behind the footrest board B, and the upper ends of these rising portions 8 extend rearward substantially horizontally to form left and right seat rails 9. ing. A U-shaped cross tube 10 extending forward and diagonally upward is welded to the upper end of the rising portion 8, and a seat 12 is supported at the extending end of this cross tube 10 via a seat bracket 11. has been done. The seat 12 is located approximately above the front half of the seat rail 9.
2, a fuel tank 13 and an oil tank 14 are installed. The fuel tank 13 is inserted between the seat rails 9, and the oil tank 14 is arranged inside the cross tube 10.
．． The outer periphery of the housing 14 is covered by a substantially cylindrical upper cover 15 whose upper and lower surfaces are open.

On the other hand, engine brackets 16 are welded to intermediate portions of the rising portions 8, respectively. Swing links 17 are pivotally supported on the engine bracket 1B, and a front end portion of a unit swing type power unit 19 is pivotally connected between these swing links 17 via a pivot shaft 18. This power unit 19 is composed of a two-stroke engine 20 and a transmission case 22 that integrally extends rearward from the left side of a crankcase 21 of this engine 20.
is located below. The rear end of the transmission case 22 is suspended from the left seat rail 9 via a hydraulic shock absorber 23, and the rear wheel 24 is connected to the rear end of the transmission case 22.
is supported on a cantilever. This rear wheel 24 is the transmission case 2
It is rotatably driven by a belt-type transmission (not shown) housed in 2.

Further, as shown in FIG. 1, the cylinder 25 of the engine 20 is attached to the front surface of the crankcase 21, and is tilted forward approximately horizontally with respect to the crankcase 21.

Therefore, the upper surfaces of the cylinder 25 and the crankcase 21 are at the road surface, and the cylinder head 26 that covers the cylinder 25 is oriented forward and inserted between the rising part of the backstay 5 and the lower end of the backstay 8. There is.

The cylinder 25 and cylinder head 26 are surrounded by an air shroud 27 having a substantially box shape. Cooling air is forcibly blown into the air shroud 27 via a fan 28 that rotates together with the crankshaft, and after cooling the cylinder 25 and cylinder head 26, the cooling air is The air is discharged outward through the air outlet 29 on the left side of the shroud 27.

Incidentally, as the cylinder 25 is tilted forward approximately horizontally as described above, a housing space 30 is formed between the upper surface of the crankcase 21 and the seat 12, and the fuel is stored in the upper part of the housing space 30. Tank 13 and oil tank 1
4 is placed. Further, an intake vibrator 31 is connected to the front portion of the upper surface of the crankcase 21, which is the bottom surface of the housing space 30. As shown in FIGS. 1 and 2, the intake vibe 31 has an elbow shape, and its intake end extends forward. And this intake vibe 31
A vaporizer 32 is connected to the suction end of. This vaporizer 3
2 is provided close to the upper surface of the front end of the crankcase 21 and straddled between the crankcase 21 and the cylinder 25, and in the case of this embodiment, the power unit)
It is located near the swing link 17 which serves as the swing fulcrum of the link 19. Further, the suction end of this carburetor 32 faces forward, and an air cleaner 34 is connected to this suction end via a joint 33 curved toward the rear.

For this reason, the air cleaner 34 is disposed behind the carburetor 32, and the air cleaner 34 and the air cleaner 34
is located at the lower part of the housing space 30 and swings integrally with the power unit 19.

An air duct 35 protruding forward is provided on the front side of the air cleaner 34, and an intake port 36 is opened at the lower surface of the protruding end of the air duct 35.

Further, the periphery of the accommodation space 30 is covered by a side cover 37 that can be divided in the left-right direction. side cover 37
The upper cover 15 continuously covers the area from around the engine 20 of the power unit 19 to around the fuel tank 13 and oil tank 14, and this side cover 37
The rear part of the seat 12 is extended rearward to accommodate the rear wheels 24.
The area from the rear fender 38 covering the seat rail 9 to the upper rear half of the seat rail 9 is integrally covered and hidden. Furthermore, the rising portion 8 of the backstay 5 is covered from the front by a front cover 39. This front cover 39 is the upper cover 1
5 and left and right side covers 37, and covers the housing space 30 and the cylinder head 2B of the engine 20 from the front.

According to such a configuration, the cylinder 25 of the engine 20
is tilted forward approximately horizontally from the front part of the crankcase 21,
The upper surface of this cylinder 25 and crankcase 21 is connected to the road surface.
At the same time, an intake vibe 31 extending forward is connected to the front upper surface of the crankcase 21, and a carburetor 32 is connected to the front end of this intake vibe 31.
2 can be disposed astride between the crankcase 21 and the cylinder 25 in a state where the cylinder 2 is close to the upper surface of the crankcase 21.

For this reason, the position of the carburetor 32 in the housing space 30 is further forward than in the past and is closer to the bottom.
2 and the cylinder 25 do not extend far into the housing space 30, and the housing space 30 can be widely opened as an installation space for the fuel tank 13 and oil tank 14 or as a storage space for small items.

Also, as the carburetor 32 moves closer to the front, this carburetor 32
The air cleaner 34 can be easily arranged between the rear wheel 24 and the rear wheel 24, and the layout of the intake system parts can be easily done.

In addition, in the case of this embodiment, since the carburetor 32 is located near the pivot point of the power unit 19, even when the power unit 19 swings during driving, the attitude of the carburetor 32 does not change much. There is also the advantage that large fluctuations in the oil level in the carburetor 32 can be prevented.

〔Effect of the invention〕

According to the present invention described in detail above, the carburetor can be placed closer to the front end of the crankcase and closer to the bottom than in the past, so that the carburetor and cylinder can be placed in the space between the crankcase and the seat. The space under the seat can be left open as a space for installing a fuel tank or for storing small items.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, in which FIG. 1 is a side view of the surroundings of a power unit, FIG. 2 is a plan view of the power unit, and FIG. 3 is a side view of a scooter type motorcycle. 2... Head pipe, 4... Down tube, 5...
...Backstay, 8...Rising part, 12...Seat, 15...Top cover, 19...Power unit, 20...Engine, 21...Crank case, 2
2... Transmission case, 24... Rear wheel, 25... Cylinder, 31... Intake pipe, 32... Carburetor, 37
...Side cover, 39...Front cover. Applicant's agent Patent attorney Takehiko Suzue

Claims (1)

[Scope of Claims] A pair of left and right back stays are connected to the rear part of the down tube connected to the head pipe, and the rear parts of these back stays are raised upward, and a seat is provided on the upper part of this raised part. The front end of a unit swing-type power unit, which is composed of an engine and a transmission case that extends rearward from one side of the engine's crankcase and has a rear wheel at its rear end, is pivotably pivoted. However, in a scooter-type motorcycle in which the area from the engine area of the power unit to the bottom of the seat is covered with a cover, the cylinder of the engine is tilted forward approximately horizontally from the front of the crankcase, and the crankcase is A scooter type motorcycle characterized in that an intake pipe extending forward is connected to the front part of the case, and a carburetor is connected to the front end of the intake pipe.