JPH03189287A - Front wheel drive device for front and rear wheel driven motorcycle - Google Patents

Abstract

PURPOSE:To bring a fork chain nearer to the center side of a vehicle body to minify the width in the right and left directions of a front fork by constituting the device so that a front wheel can be driven from a constant velocity joint provided directly under the steering shaft of the front fork through a fork chain, an idler, and a front wheel chain. CONSTITUTION:A front fork 13 is connected to the lower end of a steering shaft rotatably fitted in the head pipe 11 of a frame 2. The rear part of a swing arm 14 is rotatably fitted on the lower end of the front fork 13 through a supporting shaft 16, and a cushion unit 17 is connected between the front part of the swing arm 14 and the upper part of the front fork 13. Further, a front axle 19 rotatably supporting a front wheel 18 is tightened on the front end of the swing arm 14. The front wheel 18 is connected with the outside of a tandem idler 20 rotatably fitted on the supporting shaft 16 through a front wheel chain 21, the output shaft of a constant velocity joint 22 is connected with the inside of the tandem idler 20 through a fork chain 24, and a front wheel drive device 4 is connected with the input shaft of the constant velocity joint 22 through a connecting chain 23.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a front wheel drive device for a front and rear wheel drive motorcycle.

[Conventional technology]

Motorcycles include one- and one-wheel drive motorcycles, in which the engine drives the rear wheels and the engine also drives the front wheels. This front and rear wheel drive motorcycle has the advantage that the front and rear wheels are driven and can run smoothly even on slippery roads. The front wheels are driven by a chain or the like via a constant velocity joint installed in the front fork. For example, JP-A No. 61-81885, JP-A No. 58-206
See Publication No. 477.

[Problem to be solved by the invention]

When driving the front wheels with a chain, the chain is placed on the outside of the front wheels. For this reason, the width of the front fork increases, which causes the inconvenience that the front fork becomes large and heavy.

In view of the above, this invention is a front and rear wheel drive automatic transmission system in which the front wheel drive chain is composed of a front wheel chain and a fork chain, and the fork chain is placed inside the front wheel chain, so that the width of the front fork is narrow, compact, and lightweight. The purpose is to obtain a front wheel drive device for a two-wheeled vehicle.

[Means to solve the problem]

In order to achieve the above object, the front wheel drive device of the front and rear wheel drive motorcycle of the present invention has a shaft cylinder at the rear end of the swing arm pivotally attached to the lower ends of the left and right front forks by a support shaft, and the front wheel is attached to the front end of the swing arm. Tighten the front axle that supports the rotatably, attach the idler to the support shaft, connect the idler and the front wheel with the front wheel chain, and connect the constant velocity joint and idler installed directly below the steering shaft inside the front wheel chain. The reason is that they are connected by a hawk chain.

[Effect]

An idler attached to the front fork support shaft allows the fork chain to be placed inside the front wheel chain, which is placed on the outside of the front wheel. This allows the installation of the hawk chain to be moved closer to the center line of the vehicle, narrowing the left and right width of the front hawk, and making the front hawk smaller and lighter.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

The engine 1 is mounted on the front lower part of the frame 2. A front wheel drive device 4 and a rear wheel drive device 5 are connected to the crankshaft 3 of the engine 1.

The front wheel drive device 4 and the rear wheel drive device 5 are each configured by connecting a continuously variable belt transmission 6, a centrifugal starting clutch 7, and a gear reducer 8. It is located on the rear side and connected to the rear wheel 10 by a rear wheel chain 9. A steering shaft 12 is attached to the head pipe 11 at the front end of the frame 2 so that it can be rotated and steered.
The left and right front forks 13 are connected to the lower end of the holder and protrude downward. The left and right swing arms 14 have their rear parts bent inward and welded to the shaft tube 15, and the shaft tube 15 is swingably attached to the lower ends of the left and right front forks 13 by a support shaft 16, and the front portion of the swing arm 14 is A cushion unit 17 that expands and contracts to provide cushioning is connected between the upper part of the front fork 13 and the upper part of the front fork 13. A front axle 19 rotatably supporting a front wheel 18 is fastened to the front ends of the left and right swing arms 14. swing arm 14
Two idlers 20 are rotatably attached to the tip of the support shaft 16. Then, a front wheel chain 21 connected to the front wheel 18 on the outside of the front wheel 18 is connected to an idler 20 on the outside. Directly below the steering shaft 12 is a constant velocity joint 2.
2 is provided, and the input shaft of the constant velocity joint 22 is connected to the chain 2.
3, it is connected to the front wheel drive device 4. Also, constant velocity joint 2
The output shaft of No. 2 is connected to an inner idler 20 by a fork chain 24 inside the front wheel chain 21. thus,
The front wheels 18 are connected to the front wheel drive device 4 through a connecting chain 23, a constant velocity joint 22, a hawk chain 24, and an idler 20.
, are driven via the front wheel chain 21.

〔Effect of the invention〕

As explained above, since the present invention is configured as described above, the front wheels can be driven from the constant velocity joint provided directly under the steering shaft of the front fork via the fork chain, the idler, and the front wheel chain.

Then, the idler connects the hawk chain and the front wheel chain, and the hawk chain can be placed inside the front wheel chain, which is placed on the outside of one side of the front wheels, and the hawk chain can be placed closer to the center line of the vehicle body.

Therefore, the width of the left and right front forks can be made narrower, making it smaller and lighter.

[Brief explanation of drawings]

The figures show one embodiment of the present invention, Fig. 1 is a side view of the front fork, Fig. 2 is an exploded front view of the same, Fig. 3 is an overall side view, Fig. 4 is a plan view of the same, Fig. 5 Figure 6 is a developed plan view of the engine and front and rear wheel drive units, and Figure 6 is a side view of the same. 12... Steering shaft, 13... Front fork, 14
... Swing arm, 15... Shaft tube, 16... Support shaft, 18... Front wheel, one... Front axle, 20... Idler 21... Front wheel chain, 22... Constant velocity joint, 24...Hawk chain.

Claims (1)

[Claims] The cylinder at the rear end of the swing arm is attached to the lower ends of the left and right front forks by a support shaft, the front axle that rotatably supports the front wheel is fastened to the front end of the swing arm, and the idler is attached to the support shaft.
A front wheel drive device for a front and rear wheel drive motorcycle, characterized in that an idler and a front wheel are connected by a front wheel chain, and a constant velocity joint provided directly below the steering shaft and the idler are connected by a hawk chain inside the front wheel chain.