JPH0545471B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a vehicle for running on rough terrain in which two front steering wheels are steered by a bar handle.

(Background of the Invention) In rough terrain vehicles such as four-wheeled vehicles whose two front steering wheels are steered by bar handles, turning is often done by applying a large force to the bar handles to tilt the vehicle to the left or right. . Particularly when wide ultra-low pressure tires are installed on each wheel, the vehicle body tends to tilt left and right, and the force applied to the bar handle becomes considerably large.

Therefore, similar to conventional motorcycles, we proposed a structure in which a steering head pipe is fixed to the front end of the main tube (tank rail) that supports the fuel tank, and the upper end of the steering shaft is held here. (Utility Model Publication No. 58-149271).

(Problems with the prior art) However, in this structure, the steering handlebar is provided close to the upper end of the steering shaft cylinder, so the front part of the fuel tank is moved back so that the handlebar does not interfere with the fuel tank when turning. There will be a need to lower or lower it. Therefore, there was a problem that the fuel tank capacity became small.

Furthermore, in order to secure other tubes to the steering shaft cylinder having a circular cross section, it is necessary to reinforce it with many brackets and reinforcing members. For this reason, not only the number of parts increases due to the increase in the number of brackets and reinforcing members, but also the steering shaft cylinder is considerably thick, resulting in the disadvantage that the front part of the frame becomes large.

(Object of the Invention) The present invention was made in view of the above circumstances, and is suitable for increasing the capacity of a fuel tank.
Another object of the present invention is to provide a frame structure for a vehicle for traveling on rough terrain, which has sufficient strength and rigidity with a small number of reinforcing members, and which allows the front part of the frame to be compactly assembled.

(Structure of the Invention) According to the present invention, this purpose is to provide a sideways front axle that connects two front steering wheels, a pair of left and right front tubes extending upward from the front axle, and a fixed upper end of both front tubes. a flat bracket extending upward from the lower portion thereof, a main tube extending rearward from the rear surface of the flat bracket; and a main tube extending rearward from the rear surface of the flat bracket; The fuel tank is mounted close to the rear surface, and the front axle and both front tubes form a substantially triangular shape when viewed from the front, while the upper part of the steering shaft, which rotates together with the bar handle, This is achieved by a vehicle for running on rough terrain, characterized in that the fuel tank projects upward from a support part provided on the upper front surface of the flat bracket, and the front part of the fuel tank projects above the support part.

(Example) Fig. 1 is a perspective view of a four-wheeled vehicle that is an embodiment of the present invention, Fig. 2 is a perspective view of its frame, Fig. 3 is a side sectional view of the front upper part of the vehicle body, and Fig. 4 That's that-
The line sectional view and FIG. 5 are plan views of the fuel tank.

In these figures, the reference numeral 10 is a frame, and 2
Book front tubes 16, 16a, and 16b stand up, and a main tube 18 extends rearward from the gathering portion thereof. As a result, the front axle 14 and both front tubes 1
6 form a triangle when viewed from the front. A flat bracket 20 extending above the main tube 18 is fixed to the front surfaces of both front tubes 16 and the main tube 18.

The flat bracket 20 has bifurcated legs branching to the left and right at its lower part, and its upper part extends upward. The upper portions of the left and right front tubes 16, 16 reach the lower front end surface of the main tube 18 along the rear surface of the legs of the flat bracket 20, and are fixed to each other. Note that the upper part of the flat bracket 20 is tilted rearward so as to be substantially parallel to a steering axis 30, which will be described later.

A tunnel-shaped bracket 22 (see FIG. 4) whose side surface is approximately triangular is fixed between the rear surface of this bracket 20 and the upper surface of the main tube 18. The bracket 22 and the main tube 18 are provided with intake ports 24 and 26, as shown in FIG.
From here, the outside air enters the main tube 18, and an intake air purifier (not shown) connected to the rear end of the main tube 18
I'm starting to be guided by this. Furthermore, bracket 2
Eaves-like members 28, 28 are attached to the second intake port 24 to prevent water droplets from flowing in.

Reference numeral 30 denotes a steering shaft, and its lower end is rotatably held by a bracket 32 of the front axle 14, and its upper part is supported by a support provided on the upper front surface of the flat bracket 20. The upper part of the steering shaft 30 extends upward from this support part, and a bar handle for steering is fixed to this extended end. The steering shaft 30 steers the front wheels 12 via a steering device (not shown).

a lower tube 36 extending rearward from the front axle 14;
A vertical tube 40 connects the horizontal tube 38 fixed between the tubes 36 and the main tube 18 .

42 is a fuel tank. This tank is molded by placing powdered resin in a mold and rotating the mold while heating it in a furnace so that the resin is evenly adhered to the inner wall of the mold, and then cooled.
That is, it is made by rotational molding. This tank 42 is constructed so as to straddle the main tube 18, and its front end is close to the rear surface of the flat bracket 20. Moreover, the upper part is this flat bracket 20.
The steering shaft 30 protrudes upward from the upper support portion of the steering shaft 30 provided at the upper part of the steering shaft 30 .

The upper surface of the fuel tank 42 is formed with grooves and protrusions 44, 44a, and 44b each having a wave-shaped cross section. A large number of concave/convex stripes 44 are formed in a direction (laterally) perpendicular to the longitudinal direction (front-back direction) of the tank 42 (FIG. 5). Note that 46 is a fuel lid. These concave and convex stripes give elasticity in the longitudinal direction to the upper surface of the tank 42 and serve to prevent deformation of the tank 42 due to fuel absorption.

The tank 42 is mounted so as to straddle the main tube 18, and mounting rings 48, 48 protrude from the lower surface of the tank 42.
Bolts 54 are attached to pipes 52, 52 protruding from the vertical tube 40 via annular rubber dampers 50,
54 (Fig. 4). Also tank 42
The rear end is a bracket 5 fixed to the main tube 18.
6 via a rubber damper 58, and attached to this bracket 56 with a rubber band 60. Therefore, the deformation of the tank 42 is also absorbed by the expansion and contraction of the rubber band 60.

6 and 7 are a partially sectional side view and a front view of the top cover 62. FIG. This top cover 62 has a pair of left and right running air intakes 64, 64, and has first and third air intakes.
As shown in the figure, it is attached from the front of the lower part of the tank 42 so as to surround the steering shaft 30 and the front tube 16. The vehicle is secured to the frame 10 by screwing bolts passed through bolt holes 66, 66 provided at the lower portions of the travel air intakes 64, 64 into brackets 68, 68 secured to the front tube 16. A portion of the air taken in from the running air intakes 64, 64 enters the air intakes 24, 26, and most of the other air is guided to the inner bottom surface of the tank 42 to cool the engine 70 (FIG. 1).

8 and 9 are a side view and a plan view of the side cover 72, and FIG. 10 is a sectional view taken along the line -- in FIG. 8.
The side cover 72 includes a pair of left and right covers 72a, 7.
2b connected at their front ends. That is, as shown in FIG. 10, a protrusion 74 provided on the flange of one cover 72b is engaged with a hole in the flange of the other cover 72a, and both flanges are held between metal clips 76 to couple them together. As shown in FIG. 9, the front lower surfaces of the covers 72a and 72b are integrally formed with a horizontal flange 78 and a vertical flange 80 in the form of a downwardly bent edge of the flange 78. A small hole 82 is formed that opens in the front-rear direction.

FIG. 11 is a sectional view taken along the line XI-XI in FIG. 5 showing the vicinity of this small hole 82. As shown in this figure, an annular rubber damper 84 is attached to the small hole 82.

The side cover 72 configured in this manner is attached to surround the steering shaft 30 and the side of the tank 42 from the front. At the front of the tank 42 are pins 86, 8.
6 is integrally formed, and the damper 8 is attached to this pin 86.
4 are engaged, while the tongues 88, 88 (only one shown) formed on the upper edge of the side cover 72 are bolted to nuts 90, 90 (FIG. 5) embedded in the upper surface of the tank 42. Ru.

In this way, the front part of the side cover 72 is attached to the longitudinal pin 86, and the rear part is attached to the tank 4 by a bolt.
Since the pin 86 is attached to the damper 2, even if the tank 42 is deformed due to expansion or contraction, the pin 86 can move forward and backward within the damper 84, thereby preventing the cover 72 from deforming. Note that rubber dampers 92, 92 are attached to the upper edge of the side cover 72 (Fig. 4), and the tank 4
It is designed not to damage 2. Also, in Figures 1 and 3, 94 is a driver's seat, and the front part thereof is a tongue part 88.
is covered up. In FIG. 1, 96 is a front fender, 98 is a rear wheel, and 100 is a rear fender.

According to this embodiment, a bracket plate 20 and a bracket 22 are provided at the meeting point of the front tube 16 and the main tube 18 to disperse stress, and the bracket 22 is used to provide an air intake port 24, so that air intake during engine intake is It becomes difficult for water droplets to enter. In addition, since the gathering part is narrow and compact, it is possible to better guide the running wind to the lower part of the fuel tank, improving engine cooling performance. Furthermore, since the front part of the frame 10 has a triangular shape when viewed from the front, the strength and rigidity are extremely high, and the frame can withstand the lateral force applied to the steering shaft 30 from the handlebar 34 side and the large bending moment applied to the front axle 14. It can be done.

(Effects of the Invention) As described above, the present invention provides a flat bracket extending upward from a lower portion in which a forked leg is formed, and connects a front tube standing up from the front axle to the legs of the flat bracket. Since they are assembled at the lower front end of the main tube along the rear surface of the main tube, they can be firmly fixed to each other with a small number of reinforcing members.

In addition, the front part of the fuel tank can extend until it approaches the rear surface of the flat bracket, and the steering shaft protrudes above the support provided at the top of the flat bracket, so the front part of the fuel tank It becomes possible to extend the upper surface upwardly from this support. Therefore, the capacity of the fuel tank can be increased.

Furthermore, since the front tube and the front axle form a nearly triangular shape when viewed from the front, the lateral strength and rigidity of the front part of the frame are greatly increased, providing sufficient strength to withstand impacts from the front wheels and steering wheel. , it becomes possible to obtain rigidity. Furthermore, since the gathering part near the flat bracket can be made small and compact, it is convenient to further increase the capacity of the fuel tank that straddles this area, and to take in engine cooling air from this area.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of one embodiment of the present invention, Fig. 2 is a perspective view of the entire frame, Fig. 3 is a side sectional view of the vicinity of the front upper part of the vehicle body, Fig. 4 is a - line sectional view thereof, Figure 5 is a plan view of the fuel tank, Figures 6 and 7 are a partially sectional side view and front view of the top cover, Figure 8,
Figure 9 is a side view and plan view of the side cover, Figure 10,
FIG. 11 is a sectional view taken along the - line and the XI-XI line in FIGS. 8 and 5, respectively. 10...Frame, 12...Front wheel, 14...Front axle, 16...Front tube, 18...Main tube, 20...Flat bracket, 30...Steering shaft, 34...Bar handle, 36 ...Lower tube, 42...Fuel tank.

Claims (1)

[Claims] 1. A horizontal front axle that connects the two steering front wheels,
A pair of left and right front tubes extending upward from the front axle, a flat bracket extending upward from the forked leg section at the bottom to which the upper ends of both front tubes are fixed, and a rear surface of the flat bracket. The fuel tank is equipped with one main tube extending rearward, and a fuel tank mounted so that the front part straddles the main tube and approaches the rear surface of the flat bracket, and when viewed from the front with the front axle and both front tubes. The upper part of the steering shaft, which rotates together with the bar handle, protrudes upward from a support part provided at the upper front surface of the flat bracket, and the fuel tank is arranged above the support part. A vehicle for running on rough terrain characterized by a protruding front part.