JPH0220475B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION a. Field of Industrial Application The present invention relates to a straddle-type four-wheeled vehicle for traveling on rough terrain, which can improve maneuverability.

b. Prior Art Vehicles used for traveling on rough terrain are required to be easily balanced and have good maneuverability when the driver rides on the vehicle. Therefore, conventionally, tricycles, which are improved versions of two-wheeled vehicles, have been widely used, but structurally, they have two rear wheels attached to the frame of a two-wheeled vehicle, and fall into the category of two-wheeled vehicles.

Therefore, we decided to add 2 parts to the steering shaft of the tricycle.
A prior art technology was developed to create a four-wheeled vehicle by installing two front wheels (Utility Model Publication No. 73694, 1983).

The four-wheel vehicle described in this prior art uses a fork whose lower end of the shaft is bifurcated to support the front wheels, and the front wheels are provided on the outside of each fork. Moreover, each front wheel was equipped with a tire having the same diameter as the rear wheel, and the front fender and rear fender that covered the upper parts of these tires were molded integrally with the cover part that covered the center of the frame.

Therefore, even though the prior art had two front wheels, it was directly connected to the fork.
It only had the same function as a single wheel, and in particular, because it was equipped with two tires of the same diameter as the rear wheel, the steering wheel became extremely heavy, resulting in a decline in maneuverability.

c Problems to be solved by the invention Since a four-wheeled vehicle with balloon tires on the front and rear wheels is driven on uneven terrain such as snow, muddy terrain, and forest roads by steering with a bar handle, it is possible to use a light steering force that does not cause fatigue. I need. Furthermore, since there is an increased chance that the side surfaces of the front wheels will come into contact with stones or trees while the vehicle is running, it is necessary to prevent damage to the vehicle body parts (front fender).

The present invention solves the above-mentioned problems and provides a straddle-type four-wheeled vehicle for running on rough terrain, which has excellent maneuverability and running stability, and whose body part does not come into contact with obstacles and has excellent durability. With the goal.

d Means for Solving the Problems In order to solve the above problems, the present invention provides two front wheels and two rear wheels each equipped with balloon tires on the front left and right sides and the rear left and right sides of the frame, and a steering shaft is attached to the frame. A seat is placed vertically in the approximate center of the frame from the rear of the steering head that is rotatably supported toward the rear of the frame, and the front wheel is linked to the lower end of the steering shaft by a bar handle provided at the upper end of the steering shaft. A saddle that steers the front two wheels via a side arm, has bar steps placed between the front and rear wheels on the left and right sides of the vehicle body approximately below the center of the seat, and drives the wheels with an engine mounted between the front and rear wheels to drive over rough terrain. The vehicle is a four-wheeled vehicle, and the front wheel diameter d ₁ and tire width W ₁ are set smaller than the rear wheel diameter D and tire width W (d ₁ <D, W ₁ <W),
In addition, the width l ₂ between the left and right front wheels is set to be narrower than the width l ₃ between the rear wheels (l ₂ < l ₃ ), and the left and right steps are placed inside the width of the front wheels (l ₁ < l 3 ). l ₂ ) and
The outer edge of the front fender for the front wheels is located inside from the outside of the balloon tire and is tapered from the outermost part toward the front to improve the maneuverability of the front two wheels and to improve the front fender. To provide a straddle-type four-wheeled vehicle for traveling on rough terrain, which can prevent vehicle body parts such as the above from coming into contact with obstacles and being damaged.

e. Effects In the straddle-type four-wheeled vehicle for traveling on rough terrain of the present invention, a rider straddles the seat, puts his feet on the bar steps, and grips the bar handles to ride on the straddle-type four-wheeled vehicle. The riding position is similar to that of a motorcycle. Then, the engine is activated and the vehicle starts driving. Balloon tires are low-pressure, wide tires, so if they come into contact with or run over an obstacle such as a stone, they deform freely and absorb some of the impact.

When the bar handle is operated during a curve, the left and right front wheels are steered from the steering shaft via a link mechanism and arm. At this time, the driver uses the bar steps to help steer the vehicle around the curve by shifting his or her weight. When driving in the bushes, the tapered part of the front fender helps drive through the trees.

f Embodiment An embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a side view showing an embodiment of the straddle-type four-wheeled vehicle for traveling on rough terrain according to the present invention, FIG. 2 is a plan view of FIG. 1, and FIG. 3 is a perspective view showing the frame structure of FIG. 1. FIG. 4 is a plan view of FIG. 2 with the cover, sheet, etc. removed.

1 and 2, reference numeral 1 denotes a saddle-type body, which has front wheels 3 and rear wheels on the front left and right sides and the rear left and right sides of a frame 2 configured as shown in Figure 3. 4 are provided for each two wheels, and these front wheels 3
The rear wheels 4 are equipped with so-called balloon tires 5, which are tires with low internal pressure and a wide contact surface with the ground. The steering mechanism for steering the front wheels 3 includes a link mechanism 6 as shown in FIG.
A bar handle 7 with grips 701 attached to both ends is used as a handle for operating the link mechanism 6.

The structure of the frame 2 will be explained with reference to FIG. The frame 2 includes a pair of upper frames 8 ₁ , 8 ₂ and lower frames 9 ₁ , 9 ₂ , and a predetermined interval between the upper frames 8 ₁ , 8 ₂ and between the lower frames 9 ₁ , 9 ₂ . It is composed of a plurality of spacer frames 10 to maintain the spacer. The upper frames 8 ₁ and 8 ₂ have the tip portions 801 facing forward,
Bend diagonally downward, and behind the bent portion 802,
A predetermined length of a sloped portion 803 that slopes downward at a gentle angle is formed, and a rear end portion 804 behind the sloped portion 803 is bent horizontally or slightly upward.
These upper frames 8 ₁ , 8 ₂ have front wheels 3 at their ends.
The distal end portion 80 is connected to the axle 11 that supports the
A U-shaped fixing frame 13 for screwing the front cover 12 is attached between the two. Bent portions 802 of upper frames 8 ₁ and 8 ₂
is provided with a steering head 15 that supports the steering shaft 14 of the bar handle 7.

On the other hand, the lower frames 9 ₁ and 9 ₂ have their tips connected to the axle ₁₁ , and their rear ends ₉₀₁ are bent to stand up.
4 are connected to each other.

A bar step 16 for the driver is attached to the middle of the lower frames 9 ₁ and 9 ₂ . The width l ₁ between the bar steps 16 is determined by the width l 1 between the left and right front wheels 3,
The width l ₂ between the front wheels 3 and 3 is set so that l ₁ < l ₂ with respect to the width l ₂ between the front wheels 3 and 3, and the width l 2 between the front wheels 3 and ₃ is set to be l 1 It is set so that ₂ < l ₃ .

In addition, the diameter d ₁ of the front wheels 3, 3 and the tire width W ₁
is d ₁ for the diameter D of the rear wheels 4, 4 and the tire width W
<D, W ₁ <W is set to facilitate steering of the front wheels 3, 3.

The bent portions 902 of the lower frames 9 ₁ and 9 ₂ include
A support portion 903 that supports the drive shaft 17 of the rear wheel 4 is provided.

An engine 18, a fuel tank 19, and the like are mounted in a space A formed by these upper frames 8 ₁ and 8 ₂ and lower frames 9 ₁ and 9 ₂ .

Next, the steering mechanism for steering the front wheels 3 is connected to the fourth steering mechanism.
This will be explained using figures.

The front wheel 3 has a U-shaped frame 20 attached to both ends of the axle 11 as shown in FIGS. 5 and 6.
This mounting structure uses a king pin 21 to connect a support pipe 22a integrally provided to the wheel support shaft 22 to the frame 2.
This is done by pivoting to 0. A spacer 221 and a bush 222 are loosely fitted between the support pipe 22a and the king pin 21.

As shown in FIGS. 7 and 8, the steering shaft 14 is bolted to the steering head 15 via resin 151 so that its upper end is rotatably supported, and its lower end is placed at an intermediate position of the axle 11. It is rotatably supported by a support section 23 provided therein. An arm 24 is attached to the lower end of the steering head 14, and one end of left and right tie rods 25 are rotatably supported on the arm 24 via pins 26. The other end of the tie rod 25 is rotatably supported by an arm 28 attached to the wheel support shaft 22 via a pin 27. Thereby, the steering shaft 14 and the front wheel 3 are connected by the link mechanism 6, and the front wheel 3 is connected by operating the bar handle 7.
is steered.

On the other hand, the rear wheel 4 is supported by a drive shaft 17 to which power from an engine 18 is transmitted via a power transmission mechanism (not shown).

Next, returning to Figures 1 and 2, the body 1
The covers disposed as the exterior are the front cover 12 and the rear cover 2 combined with this.
9, and these front cover 12 and rear cover 29 integrally form a front fender 121 and a rear fender 291 on the left and right, respectively. The front fender 121 is arranged such that the outer edge 121a is located inside the outer side 5a of the balloon tire 5, and is formed in a taper that gradually becomes thinner from the outermost part O of the outer edge 121a toward the front part f. ing. The front cover 12 is provided with an air intake port 30 and a screw hole 31 on the front surface 121b of the cover between the front fenders 121, and the front cover 12 is attached to the fixing frame 13 through the screw hole 31.
is screwed to. Furthermore, this front cover 12 is provided with a protruding piece 33 having a screw hole 32 at its rear end, and this protruding piece 33 is attached to a screw hole 33 provided in the inclined part 803 of the upper frames 8 ₁ and 8 _{2 .} It is screwed to a protruding piece 34 having a hole 34a therein. On the other hand, the rear cover 29 has an open upper surface to form an opening 292, and the engine 18 and the fuel tank 19 are disposed below the opening 292. This rear cover 29 is screwed to the upper frames 8 ₁ and 8 ₂ at several locations, and the seat 35 is placed on top of the rear cover 29 .

On the other hand, a bumper 36 is attached to the axle 11 to protect the front surface of the body 1. It is composed of a plurality of auxiliary pipes 38 that are spanned over. The main pipe 37 can also be used as a lifting handle when lifting the vehicle body.
In addition, a protective plate 3 is provided on the lower side of the bumper 36.
9, the engine can be further protected.

When driving the straddle-type four-wheel vehicle for traveling on rough terrain according to the present invention, the driver straddles the seat 35, places his feet on the bar step 16, and presses the bar handle 7.
The driver holds the grip 701 in both hands while running. To make a left turn, right turn, turn, etc., the bar handle 7 is rotated in the desired direction of travel, like a normal two-wheeled vehicle. In response to this, the steering shaft 14 rotates by a predetermined angle, and the arm 24
The link mechanism 6 is operated in accordance with the rotation of the link mechanism 6. As a result, the front wheels 3, which have a smaller diameter and width than the rear wheels 4, can be easily steered by the required angle, even though the balloon tires have a larger tire contact area than normal tires, and the direction in which the vehicle is traveling can be adjusted. be changed. When making a sharp turn, the direction of the bar handle 7 is changed and the weight is shifted at the same time, causing the inner balloon tire 5 to dent, which functions similarly to the differential gear of a normal four-wheeled vehicle. As a result, sharp turns are made.

Since the balloon tires 5 of the front wheels 3 are mainly used for traveling on rough terrain, the vehicle rides while riding on or in contact with obstacles such as rocks, stones, trees, etc. At this time, since the outer edge 121a of the front fender 121 is located inside the outer side 5a of the balloon tire, there is little chance that the outer edge 121a of the front fender 121 will come into contact with an obstacle and be damaged. In particular, since the outer edge 121a of the front fender 121 is tapered gradually from the outermost part O toward the front part f, it is difficult to push through standing trees when driving in bushes such as on a beast trail. It has the effect of

Obstacles such as stones that collide with the front of the body 1 during driving are protected by the bumper 36. This bumper 36 can be used as a handle to lift the body 1 when changing the direction of the body 1.

g Effects of the Invention As described above, the straddle-type four-wheeled vehicle for traveling on rough terrain of the present invention has the following effects.

The front wheel diameter d ₁ and tire width W ₁ are smaller than the rear wheel diameter D and tire width W, respectively (d ₁ <
D, W ₁ < W), and the width l ₂ between the left and right front wheels is narrower than the width l ₃ between the rear wheels (l ₂ < l ₃ ).
For example, compared to the four-wheeled vehicle disclosed in Design Registration No. 365488 No. 1 where the front wheels have the same diameter and width as the rear wheels, the ground contact area of the front wheels is smaller and the steering force is reduced. It is possible to improve maneuverability by doing so. The front wheels have a smaller diameter and width than the rear wheels, and the width between the front wheels is smaller than the width between the rear wheels, so there is less maneuvering resistance due to obstacles such as snow and mud while driving, and there is also less rock When the side of the front wheel hits a tree, etc., the external force the bar handle receives is less impact than a large diameter or wide tire. In particular, in the case of rough terrain vehicles in which a heavy engine is placed between the front wheels and the seat above the engine is straddled, the load on the front wheels becomes large, and the small diameter and narrow front wheels are more This feature makes it easy to steer.

In addition, since the left and right steps are arranged inside the width of the front wheels (l ₁ <l ₂ ), the front wheels do not hit the feet (steps) even after the front wheels have stepped on grass, trees, etc. In addition, the outer edge of the front fender of the front wheel is located inward from the outside of the balloon tire, so when driving on narrow uneven ground, especially on a wild animal path, obstacles such as rocks or trees can be avoided. There is less chance of the front fender being damaged due to contact with the front fender. The outer edge of this front fender is tapered so that it gradually becomes thinner from the outermost part toward the front, so when driving in bushes such as beast trails, it is easy to drive through standing trees, etc. be able to.

[Brief explanation of drawings]

1 and 2 show an embodiment of the straddle-type four-wheeled vehicle for traveling on rough terrain according to the present invention, and FIG. 1 is a side view;
FIG. 2 is a plan view. Fig. 3 is a perspective view showing the frame structure in Fig. 1, Fig. 4 is a plan view shown in Fig. 2 with the cover and seat removed, and Fig. 5 is a sectional view showing the joint between the axle and the front wheel. , FIG. 6 is a sectional view taken along the line A-A in FIG. 5, FIG. 7 is a partial sectional view showing the support structure of the steering shaft, and FIG. 8 is a sectional view taken along the line A-A in FIG. 7. 1...Body, 2...Frame, 3...Front wheel, 4...Rear wheel, 5...Balloon tire, 6...
... Link mechanism, 7 ... Bar handle, 11 ... Axle, 12 ... Front cover, 14 ... Steering shaft, 16 ... Step, 24, 28 ...
...Arm, 29...Rear cover, 30...Air intake, 36...Bumper.

Claims (1)

[Claims] 1 The front left and right sides of the frame and the rear left and right sides each have two front wheels and two rear wheels equipped with balloon tires.
A seat is placed vertically in the approximate center of the frame from the rear of the steering head, which rotatably supports the steering shaft to the frame, toward the rear of the frame. The front two wheels are steered via an arm on the front wheel side linked to the front wheel, and bar steps are placed on the left and right sides of the vehicle body approximately below the center of the seat between the front and rear wheels.
It is a straddle-type four-wheel vehicle that drives the wheels with an engine mounted between the front and rear wheels and travels on rough terrain, and the front wheel diameter d ₁ and tire width W ₁ are calculated from the rear wheel diameter D and tire width W. are also small (d ₁ < D, W ₁
<W), and set the width l ₂ between the left and right front wheels to be narrower than the width l ₃ between the rear wheels (l ₂ < l ₃ ),
The left and right bar steps are located inside the width of the front wheels (l ₁ < l ₂ ), and the outside edge of the front fender for the front wheels is located inside the outside of the balloon tire, and from the outermost part to the front. A straddle-type four-wheeled vehicle for traveling on rough terrain, which is characterized by being tapered toward the top.