JPS6226167A - Three-wheeled vehicle of three wheel steering type - Google Patents

Abstract

PURPOSE:To reduce an unsprung load by configurating a device in such a way that a rear wheel steering device is rotatably but floatingly installed on a driven shaft, a body is suspended by way of the said driven shaft, and the said driven shaft is connected with a bridge section as a front wheel steering member. CONSTITUTION:A hub 31 is fitted with a shaft 35 of an equal velocity joint 36 where splines of both parts are coupled with each other, and is composed of a knuckle bracket, a king pin and the like while it is swung to right and left as required. The knuckle bracket 38 is connected integrally together with a knuckle housing 24 in a hollow cylinder form, and a bearing member 39 is provided at the other end of the knuckle housing 24 where a span S is specified. A torque arm 40 is extended to the longitudinal direction of a body frame 2 at the body side end of the housing 24. And a forward end of the torque arm 40 is bolted (43) together with the outside of a swing arm 11 by way of a connecting member 42. This configuration allows a rear wheel steering device 23 rotatably installed floatingly over a driven shaft 14.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Field of Industrial Application The present invention relates to a vehicle such as a three-wheeled motor vehicle for traveling on rough terrain that employs a three-wheel steering system.

(2) Conventional technology and problems One front steering wheel is provided in front of the vehicle body frame, and the two rear wheels are attached to one driven shaft at the rear, either directly to the vehicle body frame or via a swing arm. Vehicles such as tricycles for traveling on rough terrain are already known. The two rear wheels of such a vehicle are fixed on a single shaft, and are driven at the same rotation and the same torque, resulting in strong straight-line performance and a large understeer in the steering characteristics, which needs to be improved.

The turning operation of this type of vehicle is related to the ground load between the two rear wheels and the road surface, and mainly involves changing the traction of the left and right drive wheels as the weight of the occupant shifts, and at the same time steering the front wheel in the desired direction. Since turning requires a unique technique, steering is difficult and is not common.

(3) Purpose of the Invention The present invention relates to an improvement of a vehicle that eliminates such troubles in steering operation, and its purpose is to float the rear wheel steering device on one driven shaft and install it on the shaft. This three-wheeled wheel can be freely interlocked with the front steering wheel, and by steering the rear steering device in conjunction with the turning direction of the steering front wheel, the understeer that occurs during turning can be made into a neutral or slightly oversteer tendency. The purpose is to provide steered vehicles.

(4) Example A preferred example of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a plan view of a three-wheel steering type automatic tricycle according to the present invention;
FIG. 2 is a rear front view of the rear wheel steering device, FIG. 3 is a side view of the swing arm portion, and FIG. 4 is an explanatory schematic plan view showing the directions of the front and rear wheels and their trajectories during turning.

As is well known, a three-wheel steering type automatic tricycle (hereinafter referred to as a vehicle) 1 is provided with a head pipe 3 at the front of a body frame 2.
This inner steering shaft 4 is rotatable, and a top bridge 5 and a bottom 7-IJ ridge 6 are disposed above and below, respectively, to support a pair of left and right front forks 7, and below these are a pair of front wheels 7. The front steering wheel Wf, which is equipped with a wheel, is mounted on a steering wheel 10 so that it can be freely steered to the left or right. Further, the vehicle body frame 2 extends rearward and fixes a bracket 8, and the bracket 8 swingably supports a swing arm 11 on a pivot shaft 9. A driven sprocket 15 as a driving member and a disc brake 16 as a braking member are rotatably supported on both sides of this bearing member 13.

The driven sprocket 15 is connected via a transmission chain 17 to a driving sprocket 19 on an output shaft 18 of a power unit P disposed within the vehicle body frame 2.

In the figure, 20 indicates a cushion unit for the rear wheel, and 21 indicates a bearing.

In the above, on both sides of the driven shaft 14, specifically on the outside of the driven sprocket 15 and the disc brake 16, a rear wheel steering device 23 and a knuckle housing 24 for floating and supporting the rear wheel steering device 23 on the driven shaft 14 are arranged, and a bearing member A steering force transmission device 26 is installed on the upper part of the outer cylinder 13 via a rear bracket 25.

The above rear wheel steering device 23 will be explained in more detail with reference to FIG. 2. The rear two wheels Wr] and Wr2 are balloon tires (low pressure tires).
is fixed to the hub 31 side with a bolt 32, and the hub 3
1 is inserted into the knuckle arm 33 and is rotatable on a bearing 34, and the shaft portion 3 of the constant velocity joint 36 is inserted inside the knuckle arm 33.
5 and is spline-fitted with the knuckle arm 33, knuckle bracket 38, king pin 37, etc. so that it can freely swing left and right.

The above is the same as the conventional type of steering device, but in the present invention, in order to effectively function the driven shaft 14 as a support member interposed between the rear two wheels and the vehicle body as is well known, the knuckle bracket 38 is replaced with the knuckle housing 24 made of a hollow cylindrical member. are integrally connected, a wide span S is set at both inner ends thereof, a bearing member 39 such as a ball bearing is arranged, and the driven shaft 14 is freely rotatable by passing through the inside of the bearing member 39 vertically. Furthermore, as shown in FIGS. 1 and 3, a torque arm 40 is fixedly attached to the vehicle body side end of the knuckle housing 24 and extends in the front and rear directions of the vehicle body frame 2, and the front side of the torque arm 40 and the swing A connecting member 42 integral with a flange 41 is interposed between the outer portions of the arm 11 and screwed together with bolts 43, so that the rear wheel steering device 23 is floating and mounted on the driven shaft 14.

Therefore, the load associated with road surface fluctuations is Wry on the rear wheels.

It is transmitted from W r 2 to the knuckle arm 33, knuckle bracket 38, and knuckle housing 24, and the bearing member 3
9 and 1) is achieved by the cushioning swing of the cushion unit 20 and the swing arm 11 via the driven shaft 14.

In other words, the rear wheel steering device 23 is mounted on the rotatable driven shaft 14.
By mounting the rear wheel steering system on a floating shaft, the vehicle body is supported by the driven shaft 14, and the number of members of the rear wheel steering system can be reduced and simplified.

Next, the driven shaft 14 is preferably a well-known hollow shaft,
In addition, a spline hole 45 is provided inside both ends, and a separate system is adopted in which the constant velocity joint 36 and the driven shaft 14 are spline-coupled to the inner drive shaft 46 on the constant velocity joint 36 side to the spline hole 45.

Therefore, in the constant velocity joint 36, the shaft portion 35 and the inner drive shaft 46 are integrated into a unit, and two sets of left and right joints are prepared.

This is advantageous in assembly and maintenance compared to a structure in which constant velocity joints are provided directly at both ends of the driven shaft 14.

On the other hand, as shown in FIGS. 2 and 3, a support shaft 47 is rotatably supported in the center of the vehicle body and in the vertical direction on the rear bracket 25, and a steering arm 48 and a steering lever 49 are fixed to this. The steering shaft 4 of the bottom bridge 6, which is a steering bridge member, is arranged in a T-shape with four steering levers facing forward when viewed, and is attached to both ends of the steering arm 48 and the steering shaft 4. The two steering cables 50 and 51 are connected to each other in a freely interlocking manner by means of two steering cables 50 and 51 fixed on both sides of the center.

Ball joints 52 and 53 extending in the direction of the vehicle are attached to each of the steering levers 49, and these are connected to the left and right knuckle arms 33 by tie rods 54 and 55, respectively.

Note that 56 and 57 in the figure indicate support members for the steering cables 50 and 51.

Thus, the front wheel Wf and the two rear wheels Wr+ on the driven shaft 14.

The WF2 is equipped with independent front and rear steering devices, which are interlocked and connected to provide three-wheel steering, and the turning direction is set and operated as follows. To explain this with reference to FIG. 4, when the handlebar 10 is operated in the direction (A), the front wheel Wf and the bottom bridge 6 rotate around the steering shaft 4, and the steering cable 51 fixed thereto is pulled. As a result, the steering arm 48 is rotated about the support shaft 47 in the same direction as the bottom bridge 6, and the coaxial steering lever 49 operates the tie rods 54 and 55 in the direction of the arrow (b). Together with the rear two wheels Wr+, W
rz is steered in a direction opposite to that of the front wheel Wf, and the vehicle body turns to the left around an intersection A having this extension line as its radius.

During this turn, one front wheel Wf and two rear wheels Wry.

The sum of the respective steering angles of WF2 becomes the turning radius, and therefore a large amount of turning can be obtained with a small steering angle, and the turning ability and steering response are improved.

During the above-described turning, the rear wheels wr, Wr2 and the knuckle arm 33, which is a rear wheel steering system, are supported on the driven shaft 14 via the king pin 37, together with the knuckle bracket 38, and the bearing member 39 in the knuckle housing 24. Therefore, the vehicle can be steered without any trouble, and since the torque arm 40 is securely attached to the swing arm 11 side, the vehicle can sufficiently withstand road surface fluctuations during driving.

Of course, the steering cables 50 and 51 are also used for the buffer swinging motion of the swing arm 11 to easily and reliably transfer the steering force to the rear wheels Wr1.
It is possible to transmit Wr21.

In the embodiment, a cable (steel cable) is used as the steering force transmission means, but other well-known transmission members such as rods, links, etc. may also be freely used.

Next, FIG. 5 shows another embodiment of the present invention, in which the driven shaft 60 is of a so-called rigid type in which a bearing member 65 is directly attached to the rear of the vehicle body without using a cushion.

The rear wheel steering device 63 has the same structure as the previous embodiment, and its torque arm 62 is screwed to the side portion 64 of the vehicle body frame 61 instead of the swing arm 11.

Thus, in this embodiment as well, the same steering function and effect as in the above-mentioned embodiment can be obtained.

Of course, the rear wheel steering device of the embodiment can also be used in other multi-wheeled vehicles.

5) Unique effects of the invention The present invention produces the following unique effects.

The front wheel and the rear two wheels are each equipped with an independent steering device, which can be connected and interlocked, so that the understeer phenomenon of this type of vehicle can be avoided by the New Torque Arm.The turning performance has been significantly improved, especially on rough terrain, uneven terrain, and snowfall. Furthermore, steering operations on muddy ground, etc. become easier.

Moreover, the three-wheel steering system has one front wheel and two rear wheels, and has a lighter steering feel than the four-wheel steering system, which means less steering moment, better response, and a smaller turning radius, which improves small turning ability. Can be done. Furthermore, in order to realize the above effects, the rear wheel steering device is roughly floating on one driven shaft, the vehicle body is supported via this driven shaft, and this is connected to a bridge which is a front wheel steering member. Since it is connected to other parts, it is possible to effectively utilize the conventional method while reducing the unsprung load, improving cushioning properties,
It has many features such as being able to make the rear wheel more compact and simple.

[Brief explanation of drawings]

FIG. 1 is a plan view of a three-wheel steering type automatic tricycle according to the present invention;
Fig. 2 is a front view of the rear wheel steering system, Fig. 3 is a side view of the swing arm portion, Fig. 4 is a diagram showing the directions of the front and rear wheels and their trajectories during turning, and Fig. 5 is a diagram of the present invention. It is a top view based on another Example of. In addition, in the figure, 2 is the vehicle body frame, 6 is the bottom bridge, and 11
is a swing arm, 14 is a driven shaft, 23 is a rear wheel steering device, 24 is a knuckle housing, 33 is a knuckle arm,
38 is a knuckle bracket, 40 is a torque arm, 48
is a steering arm, and 54 and 55 are tie rods.

Claims (1)

[Claims] A three-wheeled motor vehicle for traveling on rough terrain, which is provided with one front wheel for steering at the front of the body frame, and two rear wheels disposed at the rear on one driven shaft directly on the body frame or via a swing arm. A knuckle housing, in which a rear wheel steering member consisting of a knuckle arm and a knuckle bracket is connected, is mounted on the driven shaft of the vehicle and connected to the rear wheel steering member on the outside of the driving member and the braking member, and the knuckle housing and the vehicle body frame or the swing arm are connected to each other. A three-wheel steering type motor tricycle, characterized in that the knuckle arms are connected by a torque arm and can be freely interlocked via a bridge member on the side of one front steering wheel and a steering force transmission member.