JPH0764291B2 - Saddle-type four-wheeled vehicle for running on rough terrain - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION a. Field of Industrial Application The present invention relates to a saddle-type four-wheel vehicle for traveling on rough terrain that employs a four-wheel independent suspension system and a four-wheel drive system.

b. Conventional technology Vehicles used for running on rough terrain are required to have good balance and easy maneuverability when the vehicle is carried by a driver. Therefore, a straddle-type four-wheeled vehicle has been developed in which two wheels are provided on the front and rear wheels of a two-wheeled type saddle-type frame.

Various types of saddle riding type four-wheeled vehicles have been developed, and the basic structure common to them is as follows.

That is, a saddle-ride type four-wheeled vehicle of this type is provided with two front wheels and two rear wheels on a body frame, and each of these wheels has a low internal pressure and a wide contact surface with the ground, a so-called balloon tire. Is installed. In addition, this four-wheeled vehicle uses a bar handle as a handle for operating the steering mechanism of the front wheels, and steps for placing a driver's foot are provided on both sides of the vehicle body.

Initially, the rigid suspension system was adopted for the wheels, but later improvements were made to the Wishbon suspension system for the front wheels.

c. Problem to be Solved by the Invention However, when traveling on an uneven terrain, the amplitude of the vehicle body becomes large, and there is a possibility that the traveling stability may be impaired.

An object of the present invention is to provide a saddle-ride type four-wheeled vehicle for traveling on rough terrain, which can solve the above problems and improve traveling safety.

d. Means for Solving the Problems In order to solve the above problems, the present invention provides a saddle-type narrow frame on the front left and right sides and the rear left and right sides with front wheels and rear wheels equipped with balloon tires. With two wheels, a seat is placed vertically in the center of the frame from the rear of the steering head that rotatably supports the steering shaft to the frame toward the rear of the frame, and the bar handle is provided on the upper end of the steering shaft. The front two wheels are steered via the knuckle arm on the front wheel side linked to the lower end of the steering shaft, and the steps are arranged between the front and rear wheels on the left and right of the frame below the seat, and the wheels are mounted by the engine mounted between the front and rear wheels. A saddle-ride type four-wheeled vehicle that drives and travels on an uneven terrain, comprising a pair of left and right upper tubes and a lower tube, and the upper tubes. The connecting member for connecting the lower tube and the lower tube and the bridge tube for connecting the upper tubes to each other and the lower tube to each other form the box-shaped frame having loop-shaped frame portions on the left and right sides, and the left and right front wheels are formed. Each wheel of the rear wheel and the rear wheel is swingably supported on the front and rear and right and left of the body frame by a swing arm so that the swing axis of the swing arm is oriented in the front-rear direction with respect to the vehicle traveling direction. The differential gear case for transmitting power from the engine to the front wheels and the rear wheels, respectively, in front of and behind the engine, in plan view, between the pair of left and right frame members, and in a side view, A saddle-ride type four-wheel vehicle for traveling on rough terrain, which is arranged so as to be positioned inside the loop of the loop-shaped frame portion.

e. Examples Hereinafter, the present invention will be described in detail with reference to the illustrated examples applied to a saddle-ride type four-wheeled vehicle employing a four-wheel independent suspension type suspension.

1 to 5 show a frame of a saddle type four-wheel vehicle,
1 is a side view, FIG. 2 is a plan view showing a lower tube, FIG. 3 is a plan view showing an upper tube, FIG. 4 is a front view, and FIG. 5 is a rear view. FIG. 6 is a perspective view showing a saddle-ride type four-wheeled vehicle to which the frame of the present invention is applied.

In FIGS. 1 to 5, reference numeral 1 is a body frame of a saddle-type four-wheeled vehicle that employs a double wishbon type front suspension 3 for front wheels 2 and a MacPherson type rear suspension 5 for rear wheels 4. The vehicle body frame 1 has a box type structure in which a pair of upper tubes 6 and lower tubes 7 are connected by a plurality of connecting pipes, and a long engine 8 is mounted in a central space portion.

The pair of upper tubes 6 is the steering head 9
The tip portion 5a of the portion that supports is once tilted in the front lower direction and in a direction away from each other, and approximately directly below from the middle thereof,
And bend them toward each other and connect both
To form a front portion 11. Further, the upper tube 6 forms a seat rail portion 6b for mounting a seat by inclining a rear portion of the steering head 9 portion to a middle portion in a diagonally downward direction and inclining a rear portion thereof in an obliquely upward direction. Reference numerals 12 and 13 are connection pipes that connect the upper tubes 2 to each other.

On the other hand, the pair of lower tubes 7 are connected to the front part 11 of the upper tube 6 by inclining the tip end portion 7a obliquely upward, and are connected to the rear end portion 7b by the connection pipe 14. Further, the lower tube 7 is formed such that a portion 7c for supporting a front arm 15a of the rear suspension 5 described later is in the same direction as the swing axis of the rear suspension 5. Reference numeral 16 is a pipe that connects the tip portion 7a of the lower tube 7 and the tip of the upper tube 6.

Reference numeral 17 denotes a connecting pipe 14 connecting the rear ends of the lower tubes 7 and a pair of connecting pipes connecting the rear ends of the upper tubes 6. The pair of connecting pipes 17 are curved toward each other so that a portion 17a supporting the rear arm 15b of the rear suspension 5 is narrower in width than a portion 7c supporting the front arm 15a of the rear suspension 5. Has been formed. In the embodiment, the connecting pipes 17 are connected to each other.
The portions 17a that support the rear arm 15b of the rear suspension 5 are in close contact with each other. On the other hand, the front arm 15a
Is made longer than usual by curving in an arc shape. Front arm 15a of these rear suspensions 5
A portion 7c of the lower tube 7 supporting the rear arm 15
Support fittings 18 and 19 are attached to the portion 17a that supports b, respectively.

The rear suspension 5 is a so-called diagonal swing axle type suspension, and a shock absorber 21 is arranged between the reinforcing pipe 20 and the upper tube 6. Wheel shafts (not shown) of the rear wheels 4 are individually supported by the wheel shaft support pipes 22 of the rear suspension 5, and the power from the engine 8 is individually transmitted to the wheel shafts.

On the other hand, the front suspension 3 includes an upper arm 23 and a lower arm 24 as swing arms, a front portion 11 of the upper tube 6, and a tip portion 7 of the lower tube 7.
It is rotatably supported by a support metal fitting 25 attached to a and the connecting pipe 16. Reference numeral 26 is a shock absorber that supports the front wheels 2. The upper suspension 23 (swinging arm) and the lower suspension 24 (swinging arm) of the front suspension 3 are arranged such that their swing axes are oriented in the front-rear direction with respect to the vehicle traveling direction.

The power of the engine 8 is transmitted to the front wheels 2 via a power transmission shaft 27, and the front wheels 2 are steered via a steering shaft 29 steered by a handle 28 and a link mechanism (not shown). Reference numerals 30 and 31 are reinforcing pipes provided between the upper tube 6 and the lower tube 7. As shown in FIG. 1, the reinforcing pipe 31 is detachably attached to the upper tube 6 and the lower tube 7 by being provided on either the left or right side of the vehicle body, and is attached in the middle thereof as shown in FIG. In engine suspension boss 33
Is provided. The engine 8 is supported by the engine suspension boss 33 via a mounting bolt 34 as shown in FIG. 35 is a bush.

The exhaust pipe 36 of the engine 8 is
Along the back side of the reinforcing pipe 31 provided on the side surface of the muffler, the muffler 37 is connected to the muffler 37 after extending upward. Differential gear cases 38, 39 are provided in front of and behind the engine 8, and the differential gear cases 38, 39 are seen in a plan view.
Between the left and right lower tubes 7 (frame members), and
It is arranged so as to be located in a loop (loop of the loop-shaped frame portion) constituted by the upper tube 6 and the lower tube 7 and the connecting pipe 17 in a side view.

In the frame of the saddle-ride type four-wheeled vehicle, the portion 1 that supports the rear arm 15b as the swing arm of the rear suspension 5.
The arm length of the rear suspension 5 (the distance from the fulcrum of the rear suspension to the center of the tire) is increased by making 7a higher than the portion 7c supporting the front arm 15a of the rear suspension 5 and narrowing the width. It becomes possible. Therefore, when traveling on rough terrain, the rear wheels 4
Since the change in camber can be reduced, the running stability can be improved. That is, when the wheel stroke is determined, the swing angle of the suspension is determined by the arm length. Since the camber angle is a swing angle, the camber change decreases as the arm length increases.

The swing arms of the front arm 15 (swing arm) and the rear arm 15b (swing arm) of the rear suspension 5 are arranged so as to be oriented in the front-rear direction with respect to the vehicle traveling direction.

Also, the exhaust pipe 36 of the engine 8 is reinforced with a reinforcement pipe.
Since it is arranged along the back side of 31, the reinforcing pipe 31 also serves as a heat insulating cover. Then, by removing the reinforcing pipe 31, the engine 8 can be easily attached and detached.

f. Effects of the Invention As described above, according to the saddle riding type four-wheeled vehicle for traveling on uneven terrain, the left and right front wheels and rear wheels can be rocked by the rocking arms. The four-wheel independent suspension system is most suitable for traveling on rough terrain because the suspension shafts are supported on the front, rear, left and right of the body frame.

In addition, a differential gear case that transmits power from the engine to the front wheels and the rear wheels is provided in front of and behind the engine, respectively, in plan view, between the pair of left and right frame members, and in side view, in a loop frame. Since it is arranged so as to be located inside the loop of the section, the differential gear case portion is less likely to be affected by external obstacles during traveling. Further, since the vehicle travels by four-wheel drive, traveling stability can be improved when traveling on an uneven terrain.

[Brief description of drawings]

1 to 5 show one embodiment of a frame of a saddle-ride type four-wheeled vehicle for traveling on rough terrain according to the present invention. FIG. 1 is a side view, FIG. 2 is a plan view showing a lower tube, and FIG. 3 is a plan view showing the upper tube, FIG. 4 is a front view, and FIG. 5 is a rear view. FIG. 6 is a perspective view showing a saddle type four-wheeled vehicle to which the frame of the present invention is applied. FIG. 7 is a perspective view showing a reinforcing pipe provided on a side surface of the engine, and FIG. 8 is a sectional view showing a structure for supporting the engine on an engine suspension boss of the reinforcing pipe. 1 …… Body frame 2 …… Front wheel 3 …… Front suspension 4 …… Rear wheel 5 …… Rear suspension 6 …… Upper tube 7 …… Lower tube 8 …… Engine 11 …… Front part 14,17 …… Connection Pipe 18, 19 …… Supporting metal fitting 21 …… Shock absorber

Claims (1)

[Claims] 1. A straddle-type narrow frame having two front wheels and two rear wheels equipped with balloon tires on the front left and right sides and the rear left and right sides, and a steering shaft rotatably attached to the frame. From the rear of the steering head that supports the seat, a vertically long seat is placed approximately in the center of the frame toward the rear of the frame, and the knuckle arm on the front wheel side linked to the lower end of the steering shaft is linked with the bar handle provided at the upper end of the steering shaft. A saddle-type four-wheeled vehicle that steers the front two wheels via the front and rear wheels and arranges the steps between the front and rear wheels on the left and right of the frame below the seat, and drives the wheels with an engine mounted between the front and rear wheels to drive on rough terrain. There is a pair of left and right upper tubes and lower tubes, and a connecting member that connects these upper tubes and lower tubes, A box-shaped frame having loop-shaped frame portions formed on the left and right sides is formed by a bridge tube connecting the upper tubes and the lower tubes, and the left and right front wheels and rear wheels are respectively rocked. Suspendingly supporting the suspension frame in the front-rear and left-right directions of the vehicle body frame, and arranging so that all the swinging axes of the swinging arms are oriented in the front-rear direction with respect to the vehicle traveling direction.
A differential gear case for transmitting power from the engine to the front wheels and the rear wheels is provided in front of and behind the engine, respectively, in plan view, between the pair of left and right frame members, and in side view, in a loop-shaped frame portion. A saddle-ride type four-wheeled vehicle for traveling on rough terrain arranged so as to be located inside the loop.