JPS6230861Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a fuel tank for a front-drive two-wheeled or three-wheeled vehicle having an engine mounted on the front portion.

Some motorcycles and three-wheeled vehicles use a front drive system in which the engine drives the front wheel, which is steered by a steering shaft. The engine is generally mounted in the front part that supports the front wheels. In this case, the engine is heavy, so
It is desirable that the center of gravity be moved closer to the steering axis to stabilize steering operation and improve the appearance. Furthermore, the fuel tank that supplies fuel to the engine is also installed above the front section due to the supply pipes. However, there is limited space to install a fuel tank with a relatively large capacity, so it is usually installed protruding outward, requiring large-scale fixing parts such as brackets, and increasing the distance from the steering axis. Since it contains liquid and its center of gravity is unstable, it has a considerable effect on maneuverability. It also has the disadvantage of spoiling its appearance. Ideally, the fuel tank would be located above the engine, thereby exacerbating the above-mentioned disadvantages.

In view of the above-mentioned drawbacks, this invention provides a fuel tank that is compactly installed close to the steering axis and has less impact on maneuverability and appearance.

A preferred embodiment of this invention will be described below with reference to the figures.

First, a tilting front frame type three-wheeled motor vehicle will be exemplified as a vehicle. A front frame 1 is rotatably supported by a roll shaft 3 on a rear frame 2 supported by left and right rear wheels 4 so as to be swingable from side to side, and a seat 5 is provided at the rear end.
A head pipe 6 is provided at the front end. The head pipe 6 pivotally supports a steering shaft 7.

A handle 8 is fixed to the upper end of the steering shaft 7, and a telescopic front fork 10 is fixed to the lower end. An unsprung pipe 10a pressed downward by a spring is fitted in the lower half of the front fork 10, and a front axle 11 that pivotally supports a front wheel 12 is supported at the lower end of the unsprung pipe 10a.

The engine 14 is mounted in a space 13 above the front wheel 12 sandwiched between both front forks 10. An engine bracket 15 for mounting is fixed to a mounting boss 16 of the unsprung pipe 10a by a bolt 17. The center of gravity of the engine 14 is set to substantially coincide with the axis of the steering shaft 7. A driven pulley 18 is integrally connected to one side of the front wheel 12, and a driving pulley 2 is fixed to an output shaft 19 of the engine 14.
A belt 21 is suspended between the 22 is a tension pulley. Also front wheel 1
A flat muffler 24 connected to an exhaust pipe 23 of the engine 14 is attached to the other side of the engine 14.

Next, the fork bracket 25 that connects the lower end of the steering shaft 7 and the upper end of the front fork 10 has a hollow structure made of a thin steel plate, the lower end of the steering shaft 7 is inserted and welded in the center, and the upper end is attached to both ends. A mating pipe 26 with an inner flange 27
is vertically penetrated and welded. The front fork 10 is inserted into the alignment pipe 26 from below,
It is fastened to the inner flange 27 by bolts 28, and is press-fitted to the fork bracket 25 by a slot 29 provided at the protruding lower end of the axial fitting pipe 26 and a clamp 30. In addition, the central front surface has an enlarged portion 31 that bulges forward, increasing the overall capacity. Although not shown, ribs and reinforcing plates are provided on the enlarged portion 31 and the like to ensure the strength of the fork bracket. However, the interior is undivided and communicates with one chamber, making it watertight. As shown in FIG. 2, there is an injection port 32 on the upper surface of the ampulla 31, and a supply port 3 on the lower bottom.
3 opens. A cap 34 is fitted to the injection port 32, and a supply pipe 35 is led from the supply port 33 to a carburetor 36 of the engine 14. That is, this fork bracket 25 functions as a fuel tank.

As shown in the above embodiments, the fuel tank for a front-drive automatic two- and three-wheeled vehicle according to this invention has a fork bracket that also functions as a fuel tank, reducing the number of parts and reducing weight. In addition to realizing cost reduction, it is particularly effective because it is located close to the steering axis, so steering performance is stable, and since there is no protrusion, the appearance can be made compact and the engine can be made as low as possible. Since many designs are designed to position the fuel tank in the upper position, the fuel tank is inevitably located at the top, making it possible to supply fuel using the head. It is easy to secure tank capacity without cramping the space, and it is extremely effective in putting into practical use a front-drive automatic two- and three-wheeled vehicle equipped with this type of engine in the front.

[Brief explanation of the drawing]

Figure 1 is a side view of a tilted front frame type three-wheeled motor vehicle equipped with this invention, Figure 2 is an enlarged longitudinal sectional side view of the front section of the same, and Figure 3 is a longitudinal sectional side view taken in the direction of arrow A in Figure 2. It is. 7... Steering shaft, 10... Front fork, 12... Front wheel, 14... Engine, 25... Fork bracket, 32... Inlet, 33... Supply port, 36... Carburetor.

Claims (1)

[Scope of utility model registration request] Comparison of fork brackets that are fixed to the steering shaft and support the upper ends of the front forks at both ends in front-drive automatic two- and three-wheeled vehicles with an engine mounted on the front part that supports the front wheel and swings by the steering shaft. 1. A fuel tank for a front-drive two-wheeled or three-wheeled vehicle, characterized in that the fuel tank has a hollow structure with a large target volume, and has a fuel inlet and a fuel supply inlet in the fork bracket.