JPH02261450A - Front suspension apparatus of electromotive tricycle - Google Patents

Abstract

PURPOSE:To enhance getting-over capacity by providing an angle to the segment connecting the axle center of a swing arm and the center of the front fork shaft mount part so as to position said segment on the upper side of the straight line connecting the expected difference in level on a road surface and said centers. CONSTITUTION:In an electromotive tricycle 8, a front wheel 10 is provided to the lower part of a front floor 9 to be pivotally mounted to the front end of a swing arm 17 and the swing arm 17 is mounted at a position wherein the axial line 17a of the swing arm 17 is rotated from an axle 19 by an angle a deg. from the objective line P1 connecting difference-in-level P of an objective height ready to get over and the axle 19. The force F0 at the time of the collision with the difference-in-level P is separated into force Fx ready to rotate the wheel and force Fy pushing the wheel, But, since the sing arm 17 is not positioned on the objective line P1, the force Fy is separated into the force F3 pushing the swing arm 17 and the downward force F4 due to the angle a deg. shifted from the objective line P1 of the swing arm 17, and the swing arm 17 acts in a direction raising a car body by said force F4 to support the getting- over of the difference-in-level.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a front suspension device for an electric tricycle used by physically disabled people, the elderly, and the like.

(Conventional technology) Conventionally, the front suspension device of an electric tricycle was
The rigid type structure shown in the figure was used. In this case, the axle 1a of the front wheel 1 is placed forward of the axis 2a of the steering head pipe 2 that supports the steering wheel.

For this reason, J1! ! Although the performance of overcoming bumps on the surface is improved, the unevenness of the running road is directly transmitted to the body as vibration from the steering head pipe 2, resulting in poor ride comfort when driving on rough roads. Furthermore, there are electric tricycles that use a trailing type (Fig. 7) or a leading type (Fig. 8), which are equipped with a shock absorbing mechanism that provides a more comfortable ride than the above-mentioned mechanism.

In the trailing type structure shown in FIG. 7, a swing arm 3 that pivotally supports a front wheel 1 has a front fork 4 that covers a front wheel l provided at the lower end of a steering head pipe 2.
A spring-equipped shock absorber (hereinafter referred to as a spring) 6 is provided as a buffer mechanism, which is pivotally attached to the shaft 5 located at the front end, and one end of which is connected to the swing arm 4.
The other end is hung near the front fork 4 near where the steering head pipe 2 is attached. This spring 6 alleviates the impact caused by unevenness of the traveling road.

Furthermore, in the leading type structure shown in FIG. 8, the swing arm 3 is attached differently from the trailing type, and the end of the swing arm 3 is attached to a shaft 7 provided at the rear of the front wheel of the front fork 4. has been done. Even in this case, the spring 6 alleviates the impact caused by unevenness of the traveling road and improves riding comfort. Incidentally, Japanese Utility Model Application Publication No. 55-87722 and other publications disclose a vehicle in which a climbing aid is provided on the front wheel side to reduce the impact when climbing over a step and improve riding comfort.

(Problem to be Solved by the Invention) However, with the above-mentioned trailing type or leading type structure, the important performance required for an electric three-wheeled vehicle in climbing over a step deteriorates as the cushioning property improves. In the trailing type, when the front wheel 1 hits a step, the swing arm 3 leans forward as shown by the two-dot chain line in Figure 7, and the front part of the vehicle body sinks in the direction of the arrow, making it difficult to get over the step.

In addition, in the leading type, as shown by the two-dot chain line in Fig. 8, the swing arm 3 wraps downward and the # part of the vehicle body sinks.In this way, the load is pushed forward and the performance over bumps is poor. (I can't get over a high step.)

), and the force relationship is illustrated in FIG. 8 using the leading type as an example. The force F at the time of collision with a step P on the ground is divided into a force Fx that tries to turn the wheel and a force FY that pushes the axle 1a. At this time, since the swing arm 3 is not located on the extension line of the ground level difference P and the axle 1a, the force F7 is caused by the force F [that pushes the swing arm 3] and the angle -b' at which the swing arm 3 deviates from the axle 1a. It is divided into an upward force F2. This force F2 causes the front part of the vehicle to sink, deteriorating the overpassing performance.

SUMMARY OF THE INVENTION An object of the present invention is to provide a front suspension device for an electric tricycle, which improves the riding performance by improving the above-mentioned disadvantages.

(Means for Solving the Problems) In order to achieve the above object, the present invention attaches the middle portion of the front fork 14 to the lower end of the steering head pipe 15, which has a handlebar attached to the upper end.

The rear end of a swing arm 17 is pivotally attached to a portion near the rear end of the front fork 14, and the front wheel 10 is pivotally attached to the front end of the swing arm 17. In an electric tricycle with a shock absorber (spring 21) interposed between the front end and the front fork from the center of the axle 19 of the swing arm 17! A line segment (axis line 17a) that connects the centers of the four axle mounting portions is a line between the expected step P on the road surface and the axle 19.
A line segment (axis line 17 a
) has an angle a0.

(Function) A line segment of the swing arm 17 (
When overcoming a low unevenness on the ground located below the extension line of fdltl17a), the shock absorber (spring 21) absorbs the vibration at the time of overcoming. Further, when the swing arm 17 crosses over a step P on the ground located above the extension line of the line segment (axis 17a), the rear end of the swing arm 17 crosses this step P and the axle 1.
Since it is pivoted at a position above the straight line (target line Pz) connecting 9 and has an angle a0, a force that lifts the front part of the vehicle body acts, making it easier to cross over.

(Example) Next, an example of the present invention will be described based on IT diagrams to FIGS.

The electric tricycle 8 shown in FIG. 3 has a front wheel lO provided under the front floor 9, and a drive device i13 for the rear wheel 12 provided under the rear seat 11. front fork 1
4 is connected to a steering wheel 7 provided on the front floor 9 and a vibration 15.

The suspension device for the front wheel 10 has a pin 1 provided near the rear end of the front fork 14, as shown in the figure.
The rear end of the swing arm 17 is pivotally supported by B, and the front wheel 1G is pivotally attached to the front end of the swing arm 17. In addition, the pin 18 provided at the front part of the front fork 14 and the front wheel 10
A spring 21 is provided on a pin 20 provided near the front end of the swing arm 17 near the axle 19 of the swing arm 17 .

Further, in this case, the swing arm 17 is mounted at a position rotated from the axle 19 by an angle a0 from a target line P1 connecting the axle 1B to the step P at the target height that the axis 17a of the swing arm 17 attempts to overcome. 15a is the axis of the steering head vibration 15.

In such a suspension system, the force F at the time of a bump P collision is divided into a force Fx that tries to turn the wheel (front wheel 10) and a force F7 that pushes the axle (swing arm 17), as shown in Fig. 2. . At this time, since the swing arm 17 is not located on the target line Pl, the force FY is divided into a force F3 pushing the swing arm 17 and a downward force F4 due to the angle a0 at which the swing arm 17 deviates from the target line Pl. Divided.

This force F4 lifts the front part of the vehicle body and improves the overpassing performance.

Next, the operation of the front suspension device will be explained. First, on an ordinary rough road, as shown in Fig. 4, when the swing arm 17 pushes the spring 21 and overcomes the zero step P, which is a normal suspension mechanism that cushions the impact from the road surface, as shown in Fig. 5. In addition, a force acts on the swing arm 17 in the direction of lifting the vehicle body (in the direction of stretching the spring 21), helping the vehicle to get over the bump.

When the target height of the step to be climbed is determined, the performance of the step over step is improved by the amount of force that is applied in the direction of lifting the vehicle body compared to the rigid type.

(Effects of the Invention) Since the present invention is configured as described above, the performance for climbing over bumps is better than that of the conventional rigid type steering device, and the riding comfort maintains the conventional performance. Depending on how you install the swing arm, you can prioritize one function or the other.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram showing a front suspension device of an electric tricycle according to an embodiment of the present invention, Fig. 2 is an explanatory diagram of a front suspension device of an embodiment, Fig. 1113 is a perspective view of an electric tricycle according to an embodiment, and Fig. 4 5 is an explanatory diagram of the operating state of the front suspension ventilation device of the embodiment, and FIG.
The figure is an explanatory diagram of a conventional front suspension device.
FIG. 8 is an explanatory diagram of the operating state of another conventional front suspension device, and FIG. 8 is an explanatory diagram of the operating state of another conventional front suspension device. lO...Front wheel 14...Front fork 15...Steering head pipe 17...Swing arm 17a...Axis line 21...Spring P...Step Pl...Target line a0...Angle Patent applicant Suzuki Motor Co., Ltd. Figure 4 Figure 5 Figure 6 Base 7'2

Claims (1)

[Claims] (1) Attach the middle part of the front fork to the lower end of the steering head pipe with a handle attached to the upper end, pivot the rear end of the swing arm to the part near the rear end of the front fork, and attach the front wheel to the front end of the swing arm. In an electric tricycle in which a shock absorber is interposed between a portion near the front end of the swing arm and the front end of the front fork, a line segment connecting the center of the axle of the swing arm to the center of the front fork shaft attachment portion is provided. A front suspension device for an electric tricycle, characterized in that a line segment has an angle with respect to the straight line so that the line segment is located above the straight line connecting the predicted step on the road surface and the center of the axle.