JP2003054466A - Motorcycle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To generate down force by utilizing a fuel tank, a rear cowl and a rider. SOLUTION: The fuel tank 5, a driving seat 4 of a two-seater 3 and the rear cowl 7 are longitudinally arranged in this order, and left and right both sides of the fuel tank 5 and the rear cowl 7 are largely projected to side parts as projecting parts 8 and projecting parts 9. When the rider sits on the driving seat 4 in a state of gripping knees by rear side faces of the fuel tank 5, the projecting parts 8 are approximately continued to the knees 36. The projecting parts 8 and the projecting parts 9 are respectively formed as forwardly inclined faces approximately in parallel with each other to allow the travel wind to be obliquely upwardly and backwardly escaped on their surfaces to generate the down force.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle body structure for a motorcycle, and more particularly to a vehicle body structure which is advantageous in generating downforce.

[0002]

2. Description of the Related Art As a motorcycle, a vehicle body structure is known in which a seat is arranged between a front wheel and a rear wheel, a fuel tank is arranged in front of the seat, and a rear cowl is arranged in the rear of the seat. It is also known that each side surface of a fuel tank or a rear cowl is bulged to form a ridgeline at its tip (as one example, JP-A-11-1).
71073).

[0003]

By the way, if the downforce due to the running wind can be effectively generated by utilizing the shape of the vehicle body, it can contribute to the improvement of the running performance. In particular,
If the fuel tank and the rear cowl, which are relatively large parts that are placed in front of and behind the rider and are easily contacted by the running wind, can be effectively used, it will be even more preferable because the existing parts can be effectively used.

However, there is no conventional motorcycle that uses a fuel tank or a rear cowl for such a purpose.
Even if the ridges are formed on the side surfaces of the fuel tank and the rear cowl as in the above-mentioned conventional example, this is merely for the purpose of design effect, not for aerodynamic effect. Therefore, an object of the present invention is to realize the above-mentioned request by utilizing a fuel tank and a rear cowl which are existing parts.

[0005]

In order to solve the above-mentioned problems, a motorcycle according to the present invention is a motorcycle in which a fuel tank and a rear cowl are arranged in front of and behind the driver's seat of the seat. Each of the left and right sides of the rear cowl is a projecting portion that projects laterally beyond the seat, and the leg portion of the occupant seated on the seat and these projecting portions generate downforce due to traveling wind.

At this time, the projecting portions of the fuel tank and the rear cowl are respectively inclined forward and downward in a side view,
Also, they may be substantially parallel to each other. Further, the projecting portion of the fuel tank may project above the knee grip portion.

[0007]

The left and right side surfaces of the fuel tank and the rear cowl, which are arranged in front of and behind the driver's seat of the seat, project laterally to form projecting portions, and the surfaces are used as straightening surfaces and front and rear projecting portions. Since the rectification surface is made continuous by filling the recessed space between the occupant's legs, downflow is generated by the traveling wind flowing over the surface of the overhanging portion and the legs. As a result, the vehicle body is pressed down more strongly by the down force to improve the ground contact force, so that the driving force is increased and the traveling performance is improved. Moreover, since the projecting portion is formed on the fuel tank and the rear cowl, which are existing parts, it is possible to effectively use the existing parts without requiring a special separate part for generating downforce.

At this time, by making the projecting parts of the fuel tank and the rear cowl project larger than the seat, even if an occupant is present on the seat, the legs and the projecting parts in front of and behind it act as rectifying surfaces. The running wind can be efficiently brought into contact with the occupant's torso without being disturbed, and a larger downforce can be generated. Further, the occurrence of downforce can be further increased by making the overhanging portions of the fuel tank and the rear cowl substantially parallel to each other in a front-down inclination in a side view.

In addition, by providing the overhanging portion of the fuel tank on the knee grip portion, it is possible to secure a knee grip to the fuel tank by the occupant and to travel to a portion where there is a possibility of running resistance from the knee down. The wind is hard to hit directly and the loss of downforce can be reduced.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment will be described below with reference to the drawings. FIG. 1 is a left side view of a motorcycle to which this embodiment is applied, and FIG. 2 is a plan view thereof. In these figures, the double seat 3 is arranged between the front wheel 1 and the rear wheel 2,
A fuel tank 5 and a rear cowl 7 are provided in front of the driver's seat 4 from the left and right sides of the passenger seat 6 to the rear. The fuel tank 5 and the rear cowl 7 are arranged in front and rear of the driver's seat 4, and on both left and right sides thereof. Overhanging portions 8 and 9 are formed on the.

[0011]

As shown in FIG. 2, the plan view of the fuel tank 5 has a substantially rhombic shape on the front half side, and the ridge line 8a that defines the projecting portion 8 gradually extends from the front end side toward the rear to the maximum projecting portion 8b. It forms a curve that spreads out to the side, and the maximum protrusion 8
On the contrary, the rear part from b is gradually converged toward the center of the vehicle body, and the projecting part 8 projects laterally more largely than the general side face 8c of the fuel tank 5 which is the base part thereof. In addition, the ridgeline 9a forming the contour of the overhanging portion 9 of the rear cowl 7 gradually expands from the front to the rear up to the maximum projecting portion 9b, and from the maximum projecting portion 9b, the rear gradually converges toward the vehicle body center side. .

A four-cycle water-cooled in-line four-cylinder engine 10 is arranged below the fuel tank 5, and is sucked through an air cleaner 11 and a fuel injection device 12, and exhaust gas is exhausted through an exhaust pipe 13 and a muffler 14. Exhausted. The exhaust pipe 13 passes below the engine 10, rises upward behind the pivot plate 17, intersects with the rear fork 18 in a side view, and then branches into a pair of mufflers arranged on the left and right of the vehicle body below the rear cowl 7. Connecting.
Each of the left and right mufflers is covered with a muffler cover 14 on the outer surface side.

A part of the fuel injection device 12 is covered with an injection device cover 15 disposed in the vicinity of the bottom rear part of the fuel tank and below the bottom part, and is covered with a rear side surface side cover 16 of the air cleaner 11. The side cover 16 extends below the driver's seat 4 and is in contact with the bottom thereof.

Below the side cover 16 and the engine 10
A pivot plate 17 is arranged long in the up and down direction at the rear of the pivot plate 17, the front end of the rear fork 18 is swingably supported by the pivot shaft 17a, and its vertical movement is buffered by the rear cushion 19.

A front end of a step holder 20 having a substantially Y shape in side view is attached to the rear part of the pivot plate 17, and the rear side overlaps with the rear wheel 2 in side view and is located below the passenger seat 6. The pillion step 21 for passengers is extended to the rear and is foldably attached thereto.

In the drawing, reference numeral 22 is a front fork, 23 is a head pipe, 24 is a headlight, 25 is a meter, 26 is a steering wheel, 27 is a vehicle body frame, 28
Is a rider step for a rider, 29 is a movable rear fender, 30 is a chain case, 31 is a grip bar, 3
2 is a tail lamp, 33 is a rear winker, 34 is a license plate, 35 is a rider, and 36 is its knee.

Next, the overhanging portion will be described in detail. 3 is a view showing the fuel tank from the rear side of the vehicle body, FIG. 4 is a left side view of the fuel tank, FIG. 5 is a cross section taken along line 5-5, FIG. 6 is a cross section of the rear cowl, FIG. 7 is a view of the fuel tank, the seat and the rear cowl. It is each side view which shows a relationship.

First, as shown in FIGS. 3 to 5, the front side of the fuel tank 5 has an upper surface protruding to the left and right to form a protruding portion 8, and the rear portion has a narrow width which is substantially the same as the driver's seat 4. The knee grip portion 40 is formed and is sandwiched by the knee 36 of the rider 35.

As is apparent from FIG. 5, the projecting portion 8 projects over the knee 36 in the shape of an eaves, and the lower surface 41 is a rear slope 42 which inclines obliquely downward toward the center of the vehicle body. The upper part of the center of the fuel tank 5 has a flat cap portion 43,
The front-side upper surface 44 including the cap portion 43 forms a slanted surface having a smooth curved surface that is slanted forward and left and right. The rear slope 45, which is the rear of the cap portion 43, has a smooth curved slope that obliquely descends toward the driver's seat 4 and descends to the left and right. Further, the projecting portion 8, the front side upper surface 44 and the rear side slope 45 all form a continuous smooth curved surface.

Further, as shown in FIG. 4, the projecting portion 8 is inclined obliquely downward to the front in a side view, and its rear end is continuous with the knee 36. Further, as shown in FIG.
The laterally projecting end of the overhanging portion 8 and the knee 36 have almost the same height, which is approximately the same as the vicinity of the base of the grip 26a of the handle 26, and is overhanging by a dimension a larger than the most projecting portion of the overhanging portion 9 of the rear cowl 7. ing. The most projecting portion 9b on the ridgeline 9a of the projecting portion 9 projects outward from the step 28 by a dimension b.

FIG. 6 shows a cross section of the rear cowl 7, and the tip of the projecting portion 9 projects like a wing up to near the knee 38 of the passenger 37. Reference numeral 46 in the drawing is a muffler. As shown in FIG. 7, the ridge 9a of the projecting portion 9 is inclined obliquely downward to the front, and is close to the lower end of the driver's seat 4. Further, the ridgeline 8a of the projecting portion 8 of the fuel tank 5 is similar, and the ridgelines 8a and 9a are substantially parallel to each other in a side view. Reference numeral 16a in FIG. 7 is a concave portion provided in the side cover 16, which expands rearward and is open outward.

Next, the operation of this embodiment will be described. As shown in FIG. 2 and FIG.
And flows backward over a continuous knee 36. Further, the traveling wind W flowing through the vehicle body side portion at the other lower position flows outside the legs 36 of the rider 35, flows over the overhanging portion 9, and obliquely rises backward.

At this time, the fuel tank 5 and the knee 36 are conventionally used.
Also, since the rear cowl 7 is unevenly arranged in the front and rear, a rectifying action which cannot be expected occurs. That is, since the overhanging portion 8, the knee 36, and the overhanging portion 9 integrally function as a straightener, the downwind force F is generated downward by the traveling wind W (FIG. 7).

As a result, the downforce F strongly presses the vehicle body downward to improve the ground contact force, so that the driving force is increased and the running performance is improved. Moreover, since the projecting portions 8 and 9 are formed on the fuel tank 5 and the rear cowl 7, which are existing parts, it is possible to effectively use the existing parts without requiring a special separate part for generating downforce.

At this time, by making the respective projecting portions 8 and 9 of the fuel tank 5 and the rear cowl 7 project larger than the seat 3, even if the occupant 35 is present on the seat, the leg 36 and the projecting parts before and after it are projected. Since the 8th and 9th portions are rectifying surfaces, the traveling wind W can be efficiently brought into contact with the body portion of the occupant 35 without being disturbed, and a larger downforce can be generated. Further, by causing the fuel tank 5 and the projecting portions 8 and 9 of the rear cowl 7 to be substantially parallel to each other with a front downward inclination in side view, the generation of downforce can be further increased.

In addition, by providing the overhanging portion 8 of the fuel tank 5 in the form of an eave above the knee 36 which has a knee grip, the knee grip for the fuel tank 5 by the occupant 35 can be ensured and traveling from the knee 36 to the lower side. It is possible to reduce the occurrence loss of downforce by making it difficult for the running wind W to directly hit the portion that may be caused by resistance.

[Brief description of drawings]

FIG. 1 is a side view of a motorcycle to which an embodiment is applied.

FIG. 2 Same as above

FIG. 3 is a view showing a fuel tank portion from the rear.

FIG. 4 is a side view of the fuel tank.

5 is a sectional view taken along line 5-5 of FIG.

FIG. 6 is a sectional view of a passenger seat and a rear cowl portion.

FIG. 7 is a side view of a main part showing a flow of traveling wind.

[Explanation of symbols]

3: Double seat, 4: Driver's seat, 5: Fuel tank, 6:
Passenger seat, 7: rear cowl, 8: overhang, 9: overhang, 35: rider, 36: knee

Claims (3)

[Claims] 1. A motorcycle in which a fuel tank and a rear cowl are arranged in front of and behind a driver's seat of a seat, and left and right side portions of the fuel tank and the rear cowl are projecting portions projecting laterally beyond the seat, A motorcycle, characterized in that downforce is generated by running wind by the legs of an occupant seated on a seat and these overhangs. 2. The motorcycle according to claim 1, wherein each of the projecting portions of the fuel tank and the rear cowl is inclined downward to the front and substantially parallel to each other in a side view. 3. The overhang portion of the fuel tank overhangs the knee grip portion.
The motorcycle described in.