JPH0539071A - Front wheel suspension for irregular ground running saddle riding type four-wheel car - Google Patents

Abstract

PURPOSE:To restrict variation of the camber angel at running of an irregular ground running saddle riding type four-wheel car so as to improve running stability. CONSTITUTION:In this irregular ground running saddle riding type four-wheel car provided with respective two wheels of front wheels 3 and rear wheels 4 mounted with balloon tires 5 on the front part right and left and the rear part right and left of the frame 2 of narrow width constituted into a saddle riding type, its object is attained by constituting the center lines of the oscillating shafts of supporting arms for suspending the right and left front wheels 3 oscillatably to the right and left of the frame 2 so as to be in an angle spread rearward outside the car body in a plane view.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a front wheel suspension system for a saddle-ride type four-wheeled vehicle for traveling on rough terrain.

[0002]

2. Description of the Related Art Vehicles used for traveling on rough terrain are
It is required that the driver easily balances when riding and traveling, and that maneuverability is good. Therefore, conventionally, a three-wheeled vehicle, which is an improved two-wheeled vehicle, has been widely used. However, structurally, two rear wheels are provided on the frame of the two-wheeled vehicle, which is within the range of the two-wheeled vehicle. Therefore, we developed the prior art in which a steering shaft of a three-wheeled vehicle is provided with two front wheels to make it a four-wheeled vehicle.
(No. 135686, No. 56-73694)
..

In the four-wheeled vehicle described in this prior art, a fork having a bifurcated lower end of a shaft is used to support the front wheel, and the front wheel is provided outside each of the branched forks. Moreover, tires having the same width as the rear wheels are mounted on the front wheels, and the front fenders and rear fenders that cover the upper portions of these tires are integrally formed with the cover part that covers the center of the frame. Therefore, even though the two front wheels are directly connected to the fork, such a prior art one has only the same function as one wheel, and in particular, since two tires having the same width as the rear wheel side are mounted, Became extremely heavy, and the maneuvering performance had deteriorated.

Therefore, a shaft extending in the front-rear direction of the vehicle body is provided at the lower end of the steering shaft, and front wheel support members that rotate independently about the shaft center are attached to the shaft.
A front two-wheel suspension system for a four-wheeled vehicle has been developed in which left and right front wheels are mounted on the front wheel support member (Japanese Patent Laid-Open No. 55-1027).
14 publication).

In this four-wheeled vehicle, in order to reduce the load applied to the steering shaft, the width of the front wheel balloon tire is made narrower than that of the rear wheel balloon tire, and a coil spring device is provided on the front wheel support member to enhance cushioning. I was taking measures such as.

[0006]

A straddle-type four-wheel vehicle steers a bar handle on rough terrain such as snow, mud terrain and forest roads.
Since it runs on a four-wheeled vehicle with balloon tires on the front and rear wheels, it requires a light steering force that cannot be overwhelmed. Also,
Since the vehicle runs on uneven terrain, it is necessary to effectively absorb the shock and vibration applied to the driver.

However, in the above-described saddle-ride type four-wheeled vehicle of the prior art, since the left and right front wheels are supported directly on the lower end of the steering shaft or via the front wheel support members, the load applied to the front wheels during traveling is directly , Will be transmitted to the steering shaft. For this reason, the steering wheel operation for operating the steering shaft becomes heavy, and the steering performance cannot be improved even if the width of the balloon tire is narrowed. Further, since the load is received by the steering shaft of the coil spring device provided on the front wheel support member, the impact applied to the front wheel during traveling is transmitted to the steering shaft as it is, which affects the steering performance. Further, since the front wheel support member is supported by the steering shaft, the length of the front wheel support member is also limited, and in the end, the width between the front wheels cannot be made wide enough to obtain running stability.

The present invention solves the above-mentioned problems of the prior art, improves the steering performance by lightening the operation of the steering shaft, reduces the change in the camber angle, and stabilizes the vehicle body on rough terrain. It is an object of the present invention to provide a front wheel suspension device for a saddle-ride type four-wheel vehicle for traveling on uneven terrain, which can keep the frame compact and keep the frame compact.

[0009]

In order to solve the above-mentioned problems, the present invention provides a front wheel and a rear wheel equipped with balloon tires on the front left and right sides and the rear left and right sides of a saddle type narrow frame. With two wheels, a seat is placed vertically long in the approximate center of the frame from the rear of the shaft support that rotatably supports the steering shaft with respect to the frame, and steering is performed by the bar handle provided at the upper end of the steering shaft. The front two wheels are steered via a knuckle arm on the front wheel side linked to the lower end of the shaft, and steps are arranged between the front and rear wheels on the left and right of the frame below the seat, and the wheels are driven by an engine mounted between the front and rear wheels. A saddle-type four-wheeled vehicle that travels on uneven terrain, in which the center of the swing axis of a support arm that suspends the left and right front wheels swingably to the left and right of the frame But in that it is configured to angle spreads outside of the vehicle body toward the rear in plan view.

Further, according to the present invention, two front and rear wheels equipped with balloon tires are provided on each of the front left and right sides and the rear left and right sides of a narrow straddle type frame, and a steering shaft is provided for the frame. A vertically long seat is placed approximately in the center of the frame from the rear part of the rotatably rotatably supporting shaft to the rear of the frame, and the bar handle provided on the upper end of the steering shaft links the lower end of the steering shaft to the front wheel side. A saddle-type four-wheeled vehicle that steers the front two wheels via a knuckle arm and arranges 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 In a wheeled vehicle, of the front and rear support arms that suspend the left and right front wheels swingably to the left and right of the frame, the front support arms are substantially orthogonal to the vehicle body center line. Some that were attached to that direction.

[0011]

[Operation] The saddle riding type four-wheeled vehicle for traveling on an uneven terrain according to the present invention,
Straddle the seat, put your foot on the step, hold the bar handle, and board. The riding attitude is similar to that of a motorcycle.
Then, the engine is operated to start traveling.

Since the balloon tire is a low-pressure wide tire, when it comes into contact with an obstacle such as a stone or gets on the obstacle, it is freely deformed and absorbs a shock to some extent. Particularly, since the front wheels are supported by the frame by the support arm and the suspension, the vibrations due to the unevenness of the road surface are efficiently absorbed. When the bar handle is operated during a curve, the left and right front wheels roll from the steering shaft via the link mechanism and the knuckle arm. At this time, the driver stiffens his / her feet in steps to assist in steering in a curve by moving the weight.

Since the center line of the swing axis of the support arm is formed to have an angle that widens rearward in a plan view, it serves to cancel the change in the camber angle in the wishbone type suspension.

Since the support arm is mounted in a direction substantially orthogonal to the center line of the vehicle body, the front portion of the frame can be made compact and miniaturized.

[0015]

The present invention will be described in detail below with reference to the illustrated embodiments.

FIG. 1 is a perspective view showing a saddle riding type four-wheeled vehicle for traveling on rough terrain according to the present invention, and FIG. 2 is an exploded view of a front wheel suspension device for a saddle type four-wheeled vehicle for traveling on an uneven terrain. FIG. 3 is a perspective view, FIG. 3 is a plan view of FIG. 2, and FIG. 4 is an exploded perspective view of a front wheel suspension system for a saddle type four-wheeled vehicle for traveling on rough terrain having a front suspension and a rear suspension according to another embodiment of the present invention. Is.

In FIGS. 1 and 2, reference numeral 1 denotes a saddle-riding type body, in which a front frame 3 and a rear wheel 4 are arranged on a narrow frame 2 constructed as shown in FIG. These wheels 3 and 4 are provided with so-called balloon tires 5, which have a low internal pressure and a wide contact surface with the ground. The steering mechanism for steering the wheels 3 and 4 includes:
As the link mechanism 6 as shown in FIG. 3 and a handle for operating the link mechanism 6, a bar handle 7 having grips 701 at both ends is used.

The structure of the frame 2 will be described 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 plurality of spacer frames 10 for keeping a predetermined space between the upper frames 8 _1, 8 ₂ and between the lower frames 9 _1, 9 ₂ Has been done.

The upper frame 8 _1, 8 ₂ has a tip portion 80.
1 is bent forward and obliquely downward, and a rear end portion 804 behind the tilted portion 803 is formed horizontally or a slanted portion 803 that is tilted downward at a gentle angle is formed at a predetermined length behind the bent portion 802. It is bent slightly upward. The tip of the upper frame _81, 82 are connected by spacer frame 11, and is between the tip portion 801 cross, the front cover 12
A U-shaped fixing frame 13 for screwing is attached. Bent portion 802 of upper frame 8 _1, 8 ₂
The steering shaft 14 of the bar handle 7
A steering head 15 is provided as a shaft support for rotatably supporting the.

On the other hand, the lower frames 9 _1, 9 ₂ have their front ends connected by a spacer frame 11, and the rear end portions 901 are bent to stand up, and the rear ends of the upper frames 8 _1, 8 ₂ are Each of them is connected to the section 804.

[0021] In between the rear wheels 4 and the front wheel 3, in the middle of the sheet below the said lower frame 9 _1, 9 _2, bar step 16 is mounted as a step for a rider. The width l ₁ between the bar steps 16 is such that the left and right front wheels 3,
It is set such that l ₁ <l ₂ with respect to the width l ₂ between the three wheels, and the width l ₂ between the front wheels 3 and 3 is l with respect to the width l ₃ between the rear wheels 4 and 4. It is set so that ₂ <l ₃ .

The diameter d ₁ of the front wheels 3, 3 and the tire width W ₁ are d with respect to the diameter D and the tire width W of the rear wheels 4, 4.
_By setting ₁ <D, W ₁ <W, the front wheels 3 and 3 are easily steered. The lower frame 9 _1, 9 ₂ of the bent portion 902, support portion 903 which supports the drive shaft 17 of the rear wheel 4 through bearings (not shown) is provided.

The engine 18 is placed in the space A formed by the upper frames 8 _1, 8 ₂ and the lower frames 9 _1, 9 _2.
A fuel tank 19 and the like are mounted.

Next, a steering mechanism for steering the front wheels 3 will be described with reference to FIGS. 2 and 3. The front wheel 3 is steerably attached to a U-shaped wheel support frame 20 supported by the spacer frame 11 and the lower frames 9 ₁ , 9 ₂ .

The frame 20 includes a spacer frame 11 and lower frames 9 ₁ and 9 ₂ to which a ball joint 2 is attached.
1, a front side support arm 22 ₁ and a rear side support arm 22 ₂ whose one end is swingably supported, and an upper frame 8 _1,
It is supported by the front suspension unit 23 whose upper end is supported in the middle of the front end portion 801 of 8 ₂ .

The front side support arm 22 ₁ and the rear side support arm 22 ₂ are arranged in a direction in which the front side support arm 22 ₁ is substantially orthogonal to the vehicle body center line O in a plan view, and a ball joint 21 is interposed between the spacer frame 11 and the spacer frame 11. One end is supported,
The rear side support arm 22 ₂ is supported by the lower frames 9 ₁ and 9 ₂ at one end thereof via the ball joint 21 in a diagonally forward direction.

The front side support arm 22 ₁ and the rear side support arm 22 ₂ are connected to the ball joint 2 with respect to the vehicle body center line O.
The angle α at which the swing axis center line X of 1 spreads backwards from each other α
It is installed in.

The front suspension unit 23
It is the upper end, while being supported by a bracket 23a to the middle upper frame _81, 82 of the distal portion 801 is supported by a bracket 23b and the lower end to the upper surface of the front wheel support frame 20. The front suspension unit 23 is disposed obliquely forward from the upper frames 8 _1, 8 _{2 when} viewed from the front, and is tilted so as to spread downward on both sides.

The front wheel 3 includes a support pipe integrally provided on a wheel support shaft (not shown) with a kingpin for the frame 2
It is carried out by pivoting to 0.

The steering shaft 14 has its upper end rotatably supported by the shaft supporting portion of the steering head 15, and has its lower end rotatably supported by a supporting portion 24 provided at an intermediate position of the spacer frame 11. It is supported. An arm 25 is attached to a lower end portion of the steering shaft 14, and one end portions of left and right tie rods 26 are rotatably supported by the arm 25 via a pin 27. A ball joint 28 is inserted in the middle of the tie rod 26, and the other end of the tie rod 26 is rotatably supported by a knuckle arm 29 mounted on a support pipe via a pin 30. As a result, the steering shaft 14 and the front wheel 3 are connected by the link mechanism 6, and the front wheel 3 is operated by operating the bar handle 7.
Is steered.

Next, returning to FIGS. 1 and 2, the body 1
The cover disposed as the exterior of the vehicle is divided into two parts, the front cover 12 and a rear cover 31 combined with the front cover 12, and the front cover 12 and the rear cover 31 respectively include the front fender 121 and the rear fender 311. It is formed integrally. Reference numeral 32 denotes a seat, which is placed vertically in a substantially central portion of the frame 2 from a rear portion of a shaft supporting portion that rotatably supports the steering shaft 14 toward the rear of the frame 2.

When driving the saddle-ride type four-wheeled vehicle for traveling on rough terrain according to the present invention, the driver puts his / her foot on the step 32 across the seat 32 and grips 7 of the bar handle 7.
Hold 01 with both hands and drive. Then, in order to make a left turn, a right turn, a turn, or the like, the bar handle 7 is rotated in a desired traveling direction like an ordinary motorcycle. In response to this, the steering shaft 14 rotates by a predetermined angle, and as the arm 25 rotates, the link mechanism 6 operates.
As a result, the front wheel 3 having a width smaller than that of the rear wheel 4 can be easily steered by a necessary angle and the traveling direction of the vehicle body can be changed despite the balloon tire having a larger ground contact area than the normal tire. When making a sharp turn, when the weight of the front suspension unit 2 is changed while the direction of the bar handle 7 is changed.
With the compression of 3, the inner tire balloon tire 5 is dented, which fulfills the same function as the differential gear of a normal four-wheeled vehicle.
A sharp turn is made.

At this time, since the impact is absorbed by the action of the balloon tire 5 and the front suspension unit 23, the driver can drive stably.

Further, the front side support arm 22 ₁ and the rear side support arm 22 ₂ supporting the front wheels 3 have an angle α with respect to the vehicle body center line O so that the center line X of the swing shaft spreads rearward in plan view. Because it is configured, the front wheels 3 when traveling on rough terrain
It is possible to offset the change in camber angle that accompanies the vertical movement of.

Next, FIG. 4 shows another embodiment of the present invention in which a front suspension and a rear suspension are provided. The same parts as those in FIGS. 1 and 2 are designated by the same reference numerals, and the description thereof will be omitted. Show.

The frame structure includes a lower frame 9 ₁ of FIG. _2,
The middle of 9 ₂ is cut at the rear side of step 16, and the lower frame 9 ′ ₁ , 9 ′ ₂ is cut between the cut portions by the frame 9 ′.
_1, 9 'are connected by longer joint pipe 33 ₂ width. Then, the joint pipe 33 and the upper frame 8
_1, 8 ₂ connect the rear ends with side frames 34,
Joint pipe 3 in these side frames 34
The connecting portion with 3 is set to be larger than the interval between the lower frames 9 ′ ₁ and 9 ′ ₂ .

On the other hand, the upper frames 8 _1, 8 ₂ and the joint pipe 33 are connected by two main frames 35, and a swing arm 36 for supporting the drive shaft 17 is attached to the main frames 35. There is. In this swing arm 36, one ends of two arms 361 are connected by a support shaft 362, and the support shaft 362 is pivotally supported by the main frame 35. A mounting hole 363 is provided at the other end of each arm 361 of the swing arm 36.
Is provided, and the drive shaft 17 is supported in the mounting hole 363 via a bearing (not shown).

A single rear suspension unit 37 is provided between the other end of the swing arm 36 and the upper frames 8 _1, 8 ₂ . The rear suspension unit 37 includes a spacer frame 10 whose one end is connected between the rear ends 804 of the upper frames 8 _1, 8 _2.
To the arm 36 of the swing arm 36.
The frames are connected to one another by a frame 365.

According to the straddle-type four-wheeled vehicle having the above structure, the suspension units 23 and 37 are provided on both the front wheels 3 and the rear wheels 4, so that comfortable riding can be obtained when traveling on an uneven terrain. it can.

The rear suspension unit 37
Is two provided even better between the arms 361 of the upper frame _81, 82 and the swing arm 36, The arm 36
1 may be independently supported, and the rear suspension unit 37 may be separately provided between each arm 361 and the upper frames 8 _1, 8 ₂ .

[0041]

As described above, the front wheel suspension system for a saddle-ride type four-wheel vehicle for traveling on uneven terrain according to the present invention has the following effects.

Since the center line of the swing shaft of the support arm that suspends the left and right front wheels swingably to the left and right of the frame is configured to have an angle that widens rearward in plan view, the front wheels of the front wheels are allowed to travel on rough terrain. Since it has the effect of canceling the change in the camber angle due to the vertical movement, the stability of the vehicle body during traveling can be maintained.

Among the front and rear support arms that suspend the left and right front wheels swingably to the left and right of the frame, the front support arms are mounted in a direction substantially orthogonal to the vehicle body center line, so that the front portion of the frame supports the front support arms. It is possible to reduce the size of the frame because it can be shortened to the portion that does. Further, since the distance between the tip of the balloon tire of the front wheels and the tip of the frame can be maintained, it is possible to prevent bumps or bumps on the road surface on uneven terrain from hitting the frame as much as possible.

[Brief description of drawings]

FIG. 1 is a perspective view showing a saddle-ride type four-wheeled vehicle for traveling on rough terrain according to the present invention.

FIG. 2 is an exploded perspective view showing an embodiment of a front wheel suspension system for a saddle-ride type four-wheel vehicle for traveling on rough terrain according to the present invention.

FIG. 3 is a plan view of FIG.

FIG. 4 is an exploded perspective view showing another embodiment of the present invention.

[Explanation of symbols]

1 Body 2 Frame 3 Front Wheel 4 Rear Wheel 5 Balloon Tire 6 Link Mechanism 7 Bar Handle 8 _1, 8 ₂ Upper Frame 9 _1, 9 ₂ Lower Frame 11 Spacer Frame 14 Steering Shaft 17 Drive Shaft 20 Wheel Support Frame 22 ₁ Front Side Support arm 22 ₂ Rear support arm 23 Front suspension unit 32 Seat

 ─────────────────────────────────────────────────── --- Continuation of the front page (72) Inventor Masao Kosaka 3-37-26 Sanarudai, Hamamatsu City, Shizuoka Prefecture (72) Inventor Yoshiki Shinohara 1299-54, Tomitsuka Town, Hamamatsu City, Shizuoka Prefecture

Claims (2)

[Claims] 1. A straddle-type narrow frame having two front wheels and two rear wheels mounted with balloon tires on the front left and right sides and rear right and left sides, respectively, and a steering shaft rotatably attached to the frame. A vertically long seat is placed in the approximate center of the frame from the rear of the supporting shaft to the rear of the frame, and a knuckle arm on the front wheel side is linked to the lower end of the steering shaft by a bar handle provided at the upper end of the steering shaft. It is a straddle-type four-wheeled vehicle that steers the front two 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. The center line of the swing shaft of the support arm that suspends the left and right front wheels swingably to the left and right of the frame extends outward from the vehicle body in the plan view toward the rear. A front wheel suspension system for a saddle type four-wheeled vehicle for traveling on rough terrain, which is characterized in that 2. 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, respectively, and a steering shaft rotatable about the frame. A vertically long seat is placed in the approximate center of the frame from the rear of the supporting shaft to the rear of the frame, and a knuckle arm on the front wheel side is linked to the lower end of the steering shaft by a bar handle provided at the upper end of the steering shaft. It is a straddle-type four-wheeled vehicle that steers the front two 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. Of the front and rear support arms that suspend the left and right front wheels swingably to the left and right of the frame, mount the front support arms in a direction substantially orthogonal to the vehicle body center line. A front wheel suspension system for a saddle-ride type four-wheel vehicle for traveling on rough terrain.