JPH0331624B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a scooter-type two-wheeled motor vehicle in which a forced air-cooled engine is disposed below a seat and the engine is surrounded by a cover.

[Conventional technology] In recent years, with the progress of energy saving measures, economical small two-wheeled motorcycles, so-called soft bikes, have been gaining attention as they require less fuel consumption and maintenance costs.
Various models are being developed.

Many of these small two-wheeled motor vehicles have an underbone-type frame and have a structure in which a fuel tank, oil tank, electrical components, etc. are arranged below the seat.

However, in the case of scooter-type motorcycles in which a flat footrest board, which is different from the normal bar-shaped footrest, is attached to the down tube of the frame, the engine is placed behind the footrest board, that is, on the seat or It is located below the fuel tank. In scooter-type motorcycles, complicated structural parts such as the engine and fuel tank are covered with covers to improve the appearance. It uses a forced air-cooled engine that sucks in air and blows it around the cylinders.

[Problems to be Solved by the Invention] However, if the outer periphery of the engine is covered with a cover, the engine is located in a space inside the cover that is separated from the outside, so hot air from the engine flows into this space. It becomes easy to become trapped. Particularly when the engine is stopped and idling, such as when driving in traffic or waiting at a traffic light, there is little hope for ventilation inside the cover due to the wind while the car is running, so hot air from the engine can remain inside the cover. become.

Then, since the engine fan mainly sucks air inside the cover and blows it around the cylinder,
The temperature of this engine cooling air itself becomes high, resulting in a problem that the cooling performance of the engine deteriorates.

The present invention was developed based on these circumstances, and even if the engine compartment cannot be ventilated by the wind while the vehicle is running, the hot air from the engine dissipated in the engine compartment can be reliably discharged to the outside.
It can prevent the engine from overheating, and
This hot air discharged outside is not led to the driver's upper body, and in cold weather such as winter, it can be reused to heat the driver's undercarriage, creating a comfortable driving environment. The purpose of the present invention is to provide a scooter-type two-wheeled motor vehicle that can produce the following.

[Means for Solving the Problem] Therefore, in the present invention, the rear side of the pair of left and right backstays connected to the head pipe is raised, and the upper side of this raised portion is extended substantially horizontally toward the rear of the vehicle body. A pair of left and right seat rails are formed, seats are provided on these seat rails, a forced air-cooled engine is placed below these seats, and the outer periphery of this engine is covered with a cover. In a scooter-type two-wheeled motor vehicle that has an engine compartment separated from the outside, the forced air-cooled engine has a fan that sucks cooling air and blows it around the cylinder. While located in the engine room, the front part of the cover that forms the engine room is formed with an opening that is located almost directly above the engine and opens toward the upper seat side. Covering the seat from above with the seat bottom plate of the seat, causing the peripheral edge of the seat bottom plate to protrude outward from the cover, and forming a gap between the seat bottom plate and the opening to communicate the inside and outside of the engine room, and A flange wall is formed on the peripheral edge of the seat bottom plate to extend downward and guide hot air from the engine discharged into the gap downward.

[Function] According to this configuration, hot air from the engine is dissipated into the engine room by covering the area around the engine, but this hot air rises inside the engine room due to convection and flows into the opening. from which it is discharged outwards through the gap. Therefore, even when the engine room is not expected to be ventilated by the wind while the engine is stopped, the hot air from the engine does not remain in the engine room. Temperature rise can be suppressed.

Therefore, the temperature of the cooling air sent around the cylinders can be kept low, and overheating of the engine can be prevented.

In addition, when the hot air from the engine is exhausted from the opening, the seat bottom plate that covers this opening from above protrudes outward from the cover, so the hot air hits the seat bottom plate and the flow direction is changed to sideways. It turns out. Moreover, since there is a flange wall extending downward at the peripheral edge of this seat bottom plate,
The hot air whose flow direction is horizontal is guided by the flange wall and discharged downward from the peripheral edge of the sheet along the outer peripheral surface of the cover. Therefore, despite the presence of the opening on the top surface of the cover, hot air does not blow out toward the driver's upper body.

At the same time, the hot air flows downward along the outer circumferential surface of the cover, so in cold weather such as winter, this hot air can be reused as heating air to warm the driver's undercarriage, creating a comfortable driving environment. can be produced.

[Example] The present invention will be described below based on an example shown in the drawings.

FIG. 1 shows a scooter-type two-wheeled motor vehicle, in which reference numeral 1 indicates a frame, 2 a front fork, 3 a front wheel, and 4 a handle. The frame 1 is of an underbone type, and a down tube 6 extending downward is welded to the lower rear surface of a head pipe 5 located at the front end thereof.
The lower end of the down tube 6 is bent horizontally toward the rear, and a pair of left and right back stays 8 extending rearward through a gusset 7 are welded to both left and right side surfaces of the rear end. The rear part of the backstay 8 is raised obliquely upward to the rear, and the upper ends of these rising parts 9 extend rearward in a substantially horizontal direction to form a pair of left and right seat rails 10.

A leg shield 11 that projects laterally is fixed to the head pipe 5 and down tube 6, and a flat footrest board 14 is placed on the front half of the backstay 8 via footrest brackets 12 and 13. Fixed.

Additionally, a fuel tank 1 is located between the seat rails 10.
5 is placed. The fuel tank 15 has a flange portion 16 provided on its outer circumferential surface at two locations, front and rear, which are bolted to a reinforcement reinforcement 17 welded to the outer circumferential surface of the upper end of the rising portion 9 and an upper portion of a seat bracket 18 welded to the seat rail 10. It is fixed by tightening, and a tank cap 20 is placed over a fuel inlet (not shown) on its upper surface. An oil tank 2 is located in front of the fuel tank 15.
1 are arranged side by side, and an oil tank cap 22 is placed over an oil fill port (not shown) on the top surface of this oil tank 21.

Furthermore, a bridge 23 is installed between the seat brackets 18. The bridge 23 includes a pair of load receivers 24 that straddle the upper part of the fuel tank 15 at positions spaced apart from each other in the front and back.The side walls 25 on both sides of the load receivers 24 are connected to the through bolts 26 as shown in FIG. Seat bracket 1 through
It is fixed to the outer surface of 8.

A U-shaped cross tube 28 is horizontally suspended between the upper portions of the rising portions 9. This cross tube 28 extends toward the front upper side and surrounds the oil tank 21. Further, engine brackets 29 are welded to the rear surfaces of the intermediate portions of the rising portions 9, respectively.
These engine brackets 29 have swing links 3
0 is pivoted. A power unit 32 is rotatably suspended between the swing links 30 via a pivot shaft 31. The power unit 32 is composed of a forced air-cooled two-stroke engine 33 and a transmission case 35 that integrally extends rearward from the left side of a crankcase 34 of the engine 33.
The transmission case 35 also serves as a swing arm,
A rear wheel 36 rotatably driven by a V-belt (not shown) is supported at the rear end.

A cylinder (not shown) of the engine 33 is tilted forward substantially horizontally, and the cylinder and cylinder head are covered with an air shroud 37. Further, a fan 38 is provided on the right side of the crankcase 34 and rotates integrally with a crankshaft (not shown). This fan 38 forcibly blows cooling air into the air shroud 37 to cool the area around the cylinder, and the front end of the air shroud 37 is inserted between the rising portions 9 of the left and right backstays 8. A carburetor and an intake silencer (not shown) are arranged above the crankcase 34, and a muffler 39 is arranged on the right side of the rear wheel 36 located behind the crankcase 34.

Incidentally, the outer peripheries of the fuel tank 15, oil tank 21, and cross tube 28 are covered with an upper cover 40 made of synthetic resin.
The upper cover 40 has a substantially cylindrical shape with openings on the upper and lower surfaces, and the fuel tank 1 is opened through the upper opening 41.
5 and the upper side of the oil tank 21 protrude. A collar 42 attached to the outer periphery of the through bolt 26 is inserted into both left and right side surfaces of the upper cover 40. The front surface of such an upper cover 40 is inclined along the cross tube 28, and its lower end extends forward along the rising portion 9, and when viewed from the side, it is shown in FIG. As shown, it has an abbreviated letter shape. A front cover 43 covers the space between the lower front surface of the upper cover 40 and the rear edge of the footrest board 14, that is, the front side of the rising portion 9. The front cover 43 has a locking piece 44 provided at its lower edge that is hooked to the rear edge of the footrest board 14, and its upper side is supported by a member (not shown) installed between the upper ends of the rising portion 9. By supporting the stay 45 via a screw 46, it is detachably attached along the slope of the rising portion 9.

Further, both sides of the power unit 32 are covered by a pair of side covers 47 that can be divided into left and right sides. The front edges of these side covers 47 are continuous with both side edges of the front cover 43, and approximately the front half of the upper edge is continuous with both lower edges of the upper cover 40. The rear halves extend inward and abut each other, and cover the rear portion of the seat rail 10 from above.

Further, the lower edge of the side cover 47 extends rearward along the extension line of the footrest board 14, and the rear side thereof is raised obliquely upward. A lamp unit 48 that integrally incorporates left and right flasher lamps and a tail lamp is embedded in the rear surface of these side covers 47.

A portion covered by such front cover 43 and side cover 47 constitutes an engine room 49 that is separated from the outside and communicates with the inside of upper cover 40 . Therefore, the power unit 32, carburetor, etc. are housed in the engine room 49, and as shown in FIG. 3, most of the fan 38 is located in the engine room 49. Engine room 49
It's like breathing in the air inside.

On the other hand, a seat 50 is arranged above the fuel tank 15 and oil tank 21. The seat 50 is constructed by stacking a cushion material 52 on the upper surface of a seat bottom plate 51 made of synthetic resin, and covering the cushion material 52 with a seat skin 53. Through the above cross tube 28
is attached to the extending end of the Therefore, the seat 50 is pivotally supported such that it can be opened and closed using its front end as a pivot point and its rear end pivoted upward.

A pair of suction cups 55 are attached to the front and back of the lower surface of the seat bottom plate 51, respectively, and when the seat 50 is closed,
It is adapted to be attracted to the upper surface of the load receiving part 24 so as to be able to come into contact with and separate from it. In this case, the seat bottom plate 51 covers the upper opening 41 of the upper cover 40 as well as the fuel tank 15 and the oil tank 21 from above.

In addition, the fuel tank 15 and the oil tank 21
The upper surface, except for the tank caps 20 and 22, is integrally covered with a removable rubber sheet 56.
The periphery of the upper opening 41 covers the periphery of the upper opening 41 on the rear side of the oil tank 21 . Therefore, the upper opening 41 of the upper cover 40 is connected to the oil tank 21.
Only the pivot portion on the front side, that is, the front end of the seat 50 is opened toward the upper seat bottom plate 51 side, and this opening portion 41a is located substantially directly above the engine 33. The front part of the seat bottom plate 51 extends outward from the front end of the upper cover 40, and there is an engine room 49 between the seat bottom plate 51 and the opening 41a, as shown in FIG.
A gap 57 is formed that communicates the inside and outside of the.
A flange wall 61 extending downward is provided at the peripheral edge of the seat bottom plate 51.

In the figure, reference numeral 58 denotes a rear carrier disposed behind the seat 50, and a mounting piece 60 provided on its main pipe 59 is jointly fastened to the seat bracket 18 by the through bolt 26.

According to this configuration, an opening 41a that is located substantially directly above the engine 33 and opens toward the seat bottom plate 51 is provided at the front end of the upper cover 40, and the opening 41a and the seat bottom plate 51 are connected to each other.
Since a gap 57 is formed between the engine room 49 and the inside and outside of the engine room 49, the hot air from the engine 33 dissipated into the engine room 49 rises in the engine room 49 by convection, and then enters the opening 41a. From there, it is discharged to the outside of the engine room 49 through a gap 57, as shown by the arrow in FIG.

Therefore, even in a situation where the engine compartment 49 cannot be expected to be ventilated by the wind while the vehicle is running, such as when the engine 33 is stopped in an idling state, the hot air from the engine 33 does not remain in the engine compartment 49. Therefore, a rise in temperature within the engine room 49 can be prevented.

Therefore, even though it is a fully covered type, the temperature of the engine cooling air sucked by the fan 38 can be kept low, preventing the engine 33 from overheating, and reducing the fuel supply to the fuel tank 15, carburetor, etc. Overheating of the system can also be prevented.

Further, since the engine 33 is located immediately behind the front cover 43, most of the hot air rises along the back surface of the front cover 43 and flows into the front end portion inside the upper cover 40. At the same time, the air shroud 37 that covers the cylinder and cylinder head of the engine 33 is attached to the rising portion 9 of the backstay 8.
This rising part 9
The space between them can also be used as a passage for guiding hot air to the front end portion inside the upper cover 40.

From this, if the opening 41a is provided in the front end portion of the upper cover 40, the hot air rising in the engine room 49 can be intensively discharged outward through the shortest distance as shown by the arrow in FIG. Therefore, the heat exhaust effect is promoted accordingly.

Further, when hot air from the engine 33 is discharged from the opening 41a, the peripheral edge of the seat bottom plate 51 that covers the opening 41a extends outward from the upper cover 40, so that the hot air is discharged from the seat bottom plate 51.
When it hits, the flow direction is changed to sideways.
Moreover, since a downwardly extending flange wall 61 is provided at the peripheral edge of the seat bottom plate 51, the hot air flowing laterally is guided by the flange wall 61, and the flow direction is directed downward.

Therefore, even though the opening 41a of the upper cover 40 opens upward, the hot air still flows through the sheet 50.
The hot air is discharged downward from the periphery of the vehicle, and the hot air does not blow out toward the driver's upper body.

At the same time, this hot air flows from the front edge of the seat 50 along the outer circumferential surfaces of the upper cover 40 and front cover 43 toward the footrest board 14, so in cold weather such as winter, this hot air can be transferred to the driver. It can be reused as heating air to warm the undercarriage of the vehicle, creating a comfortable driving environment.

Furthermore, according to the above configuration, the gap 57 is formed by installing the upper cover 40 and the sheet 50 at predetermined positions, so there is no need to make holes or the like in the upper cover 40, and the structure can be simplified. Furthermore, in this case, since the gap 57 is located below the sheet 50, it is not visible from the outside, which has advantages such as an advantageous appearance.

In the above embodiment, the front part of the rising part of the backstay is covered with the front cover.
The present invention is not limited to this. For example, the front edges of the left and right side covers may be extended inward, and these extended portions may be brought into contact with each other to cover the left and right side covers.

[Effects of the Invention] According to the present invention described in detail above, the hot air from the engine dissipated into the engine room rises in the engine room by convection, and then is guided to the opening, and from there passes through the gap. Since it is exhausted outward, the hot air from the engine will not remain in the engine room even when the engine room is not expected to be ventilated by wind, especially when the engine is stopped and idling. This prevents the temperature from rising inside the engine compartment. Therefore, the temperature of the engine cooling air sucked by the fan can be kept low, and overheating of the engine can be prevented.

In addition, when the hot air from the engine is exhausted from the opening, it is guided by the seat bottom plate and its flange wall, and the flow direction is sequentially changed downward, even though the cover opening faces upward. The hot air is discharged downward from the periphery of the seat along the outer circumferential surface of the cover, and the hot air does not blow out toward the driver's upper body. At the same time, this hot air flows downward from the front edge of the seat along the outer circumferential surface of the cover, so in cold weather such as winter, this hot air can be reused as heating air to warm the driver's undercarriage. In addition to the fact that the driver is not exposed to hot air, a comfortable driving environment can be created.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, in which Fig. 1 is a side view of a scooter-type two-wheeled motor vehicle, Fig. 2 is an exploded perspective view showing the attachment structure between the frame and the cover, and Fig. 3
The figure is a side view showing a partial cross section of the lower part of the seat.
The figure is a cross-sectional view taken along the line - in FIG. 3. 5... Head pipe, 8... Backstay, 9
... Rising part, 10 ... Seat rail, 15
... Fuel tank, 33 ... Engine, 38 ... Fan, 40, 43, 47 ... Cover (top cover, front cover, side cover), 41a ... Opening, 49 ... Engine room, 50 ... Seat , 51... Seat bottom plate, 57... Gap, 61...
...flange wall.

Claims (1)

[Scope of Claims] 1. A pair of left and right seat rails are formed by raising the rear sides of a pair of left and right backstays connected to the head pipe, and extending the upper portions of these raised portions substantially horizontally toward the rear of the vehicle body; By providing a seat on these seat rails, placing a forced air-cooled engine below the seat, and covering the outer periphery of the engine with a cover, an engine room separated from the outside is created below the seat. In the scooter-type two-wheeled motor vehicle, the forced air-cooled engine has a fan that sucks the cooling air and blows it around the cylinder, and this fan is located in the engine room. The front part of the cover that forms the engine room is formed with an opening that is located almost directly above the engine and opens toward the upper seat, and this opening is covered from above by the seat bottom plate of the seat. The peripheral edge of the seat bottom plate is hidden and protrudes outward from the cover, and a gap is formed between the seat bottom plate and the opening to communicate the inside and outside of the engine room, and the peripheral edge of the seat bottom plate is made to project downward. A scooter-type two-wheeled motor vehicle, characterized in that a flange wall is formed that extends downward and guides hot air from the engine discharged into the gap.