JPH0790821B2 - Suspension device for saddle type four-wheeled vehicle for running on rough terrain - Google Patents

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art Vehicles used for running on rough terrain are
It is required that the driver easily balances when riding and traveling, and that the maneuverability is good. Therefore, conventionally, a three-wheeled vehicle, which is an improved two-wheeled vehicle, has been widely used. However, structurally, the frame of the two-wheeled vehicle is provided with two rear wheels, which is within the range of the two-wheeled vehicle. Therefore, we have 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 (actual development 55-
(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 the 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 front wheels are two wheels, such a prior art one has only the same function as one wheel because it is directly connected to the fork. Especially, since two tires having the same width as the rear wheels are mounted, Was 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 balloon tire of the front wheel is made narrower than the width of the balloon tire of the rear wheel, and the coil spring device is provided on the front wheel support member to enhance the cushioning property. 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-wheel 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. Therefore, 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 wheels 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 limited, and in the end, the width between the front wheels cannot be set to a width sufficient to obtain running stability.

The present invention solves the above-mentioned problems of the prior art, lightens the operation of the steering shaft to improve the steering performance, and uses front suspensions for the front wheels.
An object of the present invention is to provide a suspension device for a saddle-type four-wheel vehicle for traveling on uneven terrain, which is capable of suspending the rear wheels by one rear suspension and absorbing the impact during traveling on rough terrain to improve boarding performance.

In order to solve the above problems, the present invention provides a straddle-type frame having a narrow width on the front left and right sides and the rear left and right sides.
Two front wheels and two rear wheels equipped with balloon tires are mounted, and a vertically long seat is placed in the approximate center of the frame from the rear of the shaft support that rotatably supports the steering shaft to the frame toward the rear of the frame, A bar handle provided on the upper end of the steering shaft steers the two front wheels through a knuckle arm on the front wheel side linked to the lower end of the steering shaft, and steps are arranged between the front and rear wheels on the left and right sides of the frame below the seat. A saddle-ride type four-wheeled vehicle that drives a wheel by an engine mounted between front and rear wheels and travels on an uneven terrain. And swingably support it, and suspend the support arm on the frame via a front suspension unit,
The left and right rear wheels are supported swingably integrally on the left and right through a swing arm extending rearward of the frame, and the swing arm is suspended at the rear of the frame through one rear suspension unit. Especially.

[0010]

[Operation] The saddle type four-wheeled vehicle for traveling on an uneven terrain according to the present invention,
Straddle the seat, put your foot on the step, grasp 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 rides on it, it is freely deformed and absorbs shock to some extent. The front wheels are supported by the support arm and the front suspension unit, and the rear wheels are supported by the frame by the swing arm and one rear suspension unit, so that the vibration due to the unevenness of the road surface is 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.

[0012]

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 perspective view of a suspension device for a saddle riding type four-wheeled vehicle for traveling on an uneven terrain. FIG. 3, FIG. 3 is a plan view of FIG. 2, and FIG. 4 is an exploded perspective view of a suspension device for a saddle-ride type four-wheel vehicle for traveling on rough terrain, which is provided with a front suspension and a rear suspension according to an embodiment of the present invention.

In FIGS. 1 and 2, reference numeral 1 denotes a saddle-riding type body, which has a narrow frame 2 configured as shown in FIG. 2 and a front wheel 3 and a rear wheel 4 for each two wheels. These wheels 3 and 4 are provided with so-called balloon tires 5, which are tires having 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 diagonally downward, and a rear end portion 804 behind the tilted portion 803 is formed horizontally or a slanted portion 803 that tilts 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 the 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 raised. Each of them is connected to the section 804.

[0018] 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 so 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 such 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, the supporting portion 903 of the bearing housing 171 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 each} having a ball joint 2 attached thereto.
1, a front support arm 22 ₁ and a rear support arm 22 ₂ whose _one ends are 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 .

[0023] The front support arms 22 ₁ and the rear support arm 22 ₂ is a plan view along the line front support arm 22 ₁ is the longitudinal direction of the vehicle body center line O substantially perpendicular, outward from the spacer frame 11 The rear side support arm 22 ₂ is extended from the lower frames 9 ₁ and 9 _{2 in a} diagonally forward direction. One end of the front side support arm 22 ₁ is supported by the spacer frame 11 via the ball joint 21, and the other end of the rear side support arm 22 ₂ is supported by the lower frames 9 ₁ , 9 ₂ via the ball joint 21. ing.

In the front side support arm 22 ₁ and the rear side support arm 22 ₂ , the line X connecting the center line of the ball joint (swing shaft) 21 to the vehicle body center line O is outside on the front end side and on the rear end side The ball joints (swing shafts) 21 of the front side support arm 22 ₁ and the rear side support arm 22 ₂ are arranged so as to form an angle α that spreads with each other.

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 so as to be tilted so as to spread downward from both sides of the upper frames 8 _1, 8 ₂ when viewed from the front, and is disposed obliquely downward toward the front when viewed from the side. There is.

The front wheel 3 has a support pipe integrally provided on a wheel support shaft (not shown) formed by a kingpin on the frame 2
It is performed by pivoting to 0.

The steering shaft 14 has its upper end rotatably supported by the shaft support of the steering head 15, and has its lower end rotatably supported by a support 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 above-mentioned saddle-ride type four-wheeled vehicle for running on uneven terrain, the driver straddles the seat 32, puts his / her foot on the step 16, and holds the grip 701 of the bar handle 7 with both hands. To run. Then, in order to make a left turn, a right turn, a turn, etc., 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 the link mechanism 6 is operated in accordance with the rotation of the arm 25. As a result, the front wheel 3 having a width smaller than that of the rear wheel 4 is achieved despite the balloon tire having a larger ground contact area than the normal tire.
Can be easily steered by a required angle to change the traveling direction of the vehicle body. And when making a sharp turn,
When the weight of the bar handle 7 is changed at the same time as the direction of the bar handle 7 is changed, the balloon tire 5 on the inner wheel side is recessed as the front suspension unit 23 is compressed, and this functions like a differential gear of a normal four-wheeled vehicle. , A sharp turn, etc.

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

Next, FIG. 4 shows an 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.

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 frame 9 ′ is cut between the cut portions of the lower frames 9 ′ ₁ and 9 ′ _2.
1, 9 'are connected by longer joint pipe 33 ₂ width. Then, the joint pipe 33 and the upper frame 8
_1, 8 ₂ rear ends are connected by 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 the bearing housing 171 of the drive shaft 17 shown in FIG. 3 is connected to the main frames 35. A swing arm 36 for supporting the is attached. This swing arm 36
Connects one end of two arms 361 with a support shaft 362, and connects the support shaft 362 to the main frame 35.
It is pivotally supported on. Swing arm 36
A support portion 364 having a mounting hole 363 is provided at the other end of each arm 361, and the drive shaft 17 is supported in the mounting hole 363 via the bearing housing 171.

A 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 swing arm 36 at the other end.
The frames are connected to one another by a frame 365.

According to the straddle-type four-wheeled vehicle having the above-mentioned structure, the front suspension unit 23 is provided on the front wheels 3 and the single rear suspension unit 37 is provided on the rear wheels 4, so that it is comfortable when traveling on rough terrain. The boarding property can be obtained.

Even one rear suspension unit 37 is lightweight, so that the vehicle can be sufficiently supported.

[0037]

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

The left and right front wheels are independently swingably supported on the left and right front portions of the frame via support arms, and the support arms are suspended on the frame via a front suspension unit. Left and right rear wheels are supported swingably integrally on the left and right via a swing arm extending rearward of the frame, and the swing arm is suspended on the rear of the frame via a rear suspension unit. Since the front wheels are suspended by the wishbone type suspension and the rear wheels are suspended by the swing arm type suspension, it is possible to improve the rideability on rough terrain. Further, since the vehicle body is lightweight and the balloon tire has a cushioning action, the left and right rear wheels can be supported by one rear suspension unit.

[Brief description of drawings]

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

FIG. 2 is an exploded perspective view showing an embodiment of a front wheel suspension device for a saddle-ride type four-wheeled vehicle for traveling on rough terrain.

FIG. 3 is a plan view of FIG.

FIG. 4 is an exploded perspective view showing an embodiment of a suspension device for a saddle-ride type four-wheeled vehicle for traveling on rough terrain according to 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 36 Swing arm 37 Rear suspension unit

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshiki Shinohara 1299-54 Tomitsuka-cho, Hamamatsu-shi, Shizuoka (56) References Automotive Engineering Complete Book 11, Chapter 1, "Steering, Suspension" 1.3 Basic wheel support (P.P.7-11) and Chapter 4 Suspension in Practice (P.P.93-133), supervised by Taihei Oguchi, published by Sankaido Co., Ltd., first edition issued August 20, 1980.

Claims (1)

[Claims] 1. A straddle-type narrow frame is provided with 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 is rotatably attached to the frame. A vertically long seat is placed in the 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 on 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. Support the left and right front wheels independently on the left and right front portions of the frame via support arms, and support the support arms on the front support. The left and right rear wheels are suspended by a suspension unit, and the left and right rear wheels are swingably supported integrally by a swing arm extending rearward and rearward of the frame. A suspension device for a saddle-ride type four-wheel vehicle for traveling on rough terrain, characterized in that the suspension device is suspended on the rear portion of the frame via a rear suspension unit.