JPS58221784A - Belt drive type motorcycle - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a motorcycle in which engine power is transmitted to the rear wheels via a toothed belt.

Chain drive systems and shaft drive systems are known as secondary transmission systems for motorcycles, but recently a belt drive system using a toothed belt has been put into practical use. When a toothed belt is used to drive the rear wheel of a motorcycle, when the swing arm swings up and down, the center of swing of the swing arm is located between the engine side Sugerocket and the rear wheel side Tin Rocket. There are drawbacks such as the distance between the shafts between these two Suge rockets being reduced, and the tension of the toothed belt being reduced, causing tooth skipping.

In order to deal with this problem, a structure has been developed that uses rollers to apply tension to the toothed belt, as shown in Japanese Utility Model Application Publication No. 57-33347.

However, in this prior art, the rollers are movable, and the rollers are pressed against the toothed belt by springs, so when the toothed belt becomes loose, the pressing force of the rollers naturally weakens, and therefore, the toothed belt is constantly pressed against the toothed belt. It becomes difficult to apply constant tension.

The present invention was made based on these circumstances, and
The purpose is to provide a belt-driven motorcycle that can reliably transmit power by reducing the loosening of the toothed belt due to swinging of the swing arm.

That is, the present invention has a configuration in which a roller is fixedly arranged near the toothed belt on the vehicle body, and the roller presses the toothed belt when the swing arm is oscillated. This aims to achieve the above objectives.

A first embodiment of the present invention will be described below with reference to FIGS. 1 to 6.

FIG. 1 shows a side view of a motorcycle, with reference numeral 1 a frame constituting the vehicle body, 2 a front fork, 3 a front wheel, 4 a fuel tank, and 5 a seat.

The frame 1 of this embodiment includes a helad pipe 6, a pair of left and right down tubes 7, 7, and seat pillar tubes 8, 8.
, seat rails 9,9, and backstays 10.10
The main structure is a double cradle type frame 1, and an engine 11 is mounted on this frame 1. Bracket 1 is attached to the front of the lower end of the seat pillar tube 8.8.
2.12 (only one side shown) is welded on these! A front end portion of a swing arm 14 is pivotally supported between the rackets 12112 via a pivot shaft 13 so as to be swingable in the vertical direction.

A rear wheel 16 is pivotally supported at the rear end of the swing arm I4 via an axle 15. It is suspended by a pair of buffers 77.17 (only one shown).

A gear case 19 is integrally connected to the rear of the crankcase 18 of the engine 11, and a drive sprocket 20 is provided within the gear case 19 on the left side in the direction of movement. A driven sprocket 21 is fixed to the hub of the rear wheel I6, and an endless toothed belt 22 is connected between the driven sprocket 21 and the drive sprocket 20.
is installed. Therefore, the drive rocket 20 of the engine 11 drives the rear wheel 16 via the belt 22 with m. Then, the toothed belt 22 has a predetermined tension of 0.
However, this tension is applied when the centers of the driving tin rocket 20, the driven tin rocket 21, and the pivot shaft 13 are located on the same straight line 01T01, as shown in FIG. 4, that is, the driving tin rocket 20 The distance between the axes and the driven Sugerocket 21 is adjusted to be appropriate when the distance is maximized. The toothed belt 22 is passed through the inside of the lower end of the seat biller tube 8, and rollers 25 and 26 are disposed on the outer sides of the tension side 23 and the loose side 24 of the toothed belt 22, respectively. The rows 22.5.26 of this example are the sleeve 2
It is constructed by attaching an outer ring 28 made of synthetic resin to the outer periphery of the seat biller tube 7, and is rotatably supported by a bracket 29, 29 welded to the rear surface of the lower end of the seat biller tube 8.

In other words, the rollers 25 and 26, as shown in FIG.
By inserting the collar 31 on the outer periphery of the pivot pin 30 protruding from the bracket 29.29 and inserting the sleeve 27 on the outer periphery of the collar 31, it is pivotally supported on the bracket 29.29. υ is located rearward of the pivot shaft 13 of the swing arm 14. These rollers 25 and 26 are driven by a tin rocket 20. In a state where the centers of the driven Sugerocket 21 and the pivot shaft 13 are aligned on the same straight line O1-ol, the toothed belt 22
It is designed to make slight contact with the tension side 23 and the loose side 24 of.

Next, the operation of the above structure will be explained with reference to FIGS. 5 and 6.

If the rear wheel 16 sinks due to the impact, the rear end of the swing arm I4 will be in a straight line 0 as shown in FIG. -0, Yoshi also rotates upward. Then, the distance between the shafts between the driving sprocket 20 and the driven megrocket 21 will be reduced, so
The toothed belt 22 tries to loosen. However, when the toothed belt 22 rotates together with the swing arm Z4, the apparently upper roller 25 bites into the outer surface of the tensioned side 23 and presses the tensioned side 23 from the outside to the inside. Tension is applied to the toothed belt 22.

On the other hand, when the rear wheel 16 lifts while driving, the swing arm I4
Even if the rear end rotates downward in a straight line, the driving Sugerocket 20, the driven Sugerocket, and the To 21
Since the distance between the shafts is reduced, the toothed belt 22 tends to loosen in the same manner as described above. However, this time toothed belt 2
The lower roller 26 bites into the outer surface of the loose side 24 of the toothed belt 22 and presses the loose side 24 from the outside to the inside, so that tension is applied to the toothed belt 22.

Therefore, as can be seen from the above description, with this configuration, when the swing arm 14 swings up and down, the loosening that would normally occur in the toothed belt 22 is caused by the rollers 25.
6, resulting in less tension drop.

For this reason, tooth skipping is less likely to occur, which has the effect of ensuring reliable power transmission.

In the first embodiment described above, the rollers 25° 26 are provided outside the tension side 23 and the loose side 24 of the toothed belt 22, but for example, as shown by the imaginary lines in FIG.
It may also be provided inside the loose side 24. In this case, when the swing arm 14 is oscillated upward, the lower row 226 bites into the inner surface of the loose side 24 and presses the loose side 26 from the inside to the outside, and conversely, the swing arm I4 moves downward. When the upper roller 25 is swung, the upper roller 25 sinks into the inner surface of the upholstery side 23 and presses the upholstery side 23 from the inside to the outside, so that the direction of suppression is reversed.

Furthermore, in carrying out the present invention, it is not necessary to provide two rollers, and as in the second embodiment shown in FIGS. side 24
A configuration may also be adopted in which one row 241 is placed between the bit and shaft 13 of one swing arm 14 and located at the rear. According to this second embodiment, the swing arm 14
When the roller 41 is rotated upward, the roller 41 presses the slack side 24 of the toothed belt 22 from the inside to the outside as shown in FIG. As shown in the figure, turn the tensioned side 23 from the inside to the outside.
It will be suppressed. Therefore, in this configuration, as in the first embodiment, loosening of the toothed belt 22 due to the swinging displacement of the swing arm 14 can be reduced.

The present invention described in detail above has a configuration in which a roller is fixedly arranged near the toothed belt on the vehicle body, and the roller presses the toothed belt when the swing arm is oscillated. The loosening of the toothed belt caused by the swinging displacement of the arm is reduced, so there is no tooth skipping, and power transmission can be ensured.

[Brief Description of the Drawings] Figures 1 to 6 show a first embodiment of the present invention.
The figure is a side view of the motorcycle, Figure 2 is an enlarged side view of the power transmission system, and Figure 3 is a sectional view showing the roller assembly + Jllll structure.
4 to 6 are explanatory diagrams of the operation, and FIGS. 7 to 9 are explanatory diagrams of the operation of the second embodiment of the present invention. 1... Vehicle body (frame), 11... Engine, 14
... Swing arm, 16... Rear wheel, 20... Driving Sugerocket, 21... Driven Sugerocket, 22.
...Toothed belt, 25'! 6.41... Laura. Applicant's agent Patent attorney Takehiko Suzue 4ag 5 Figure 5/-7 Figure 2

Claims (1)

[Claims] It has a vehicle body on which an engine is mounted, and a swing arm that pivotally supports a rear wheel.The swing arm has a front part that can swing vertically relative to the vehicle body, and the center of this swing is a drive that outputs engine power. It is installed behind the Sugerocket, and an endless toothed belt is wound between this driving Sugerocket and a driven sprocket fixed to the rear wheel.
In a motorcycle that transmits engine power to the rear wheel,
A belt-driven motorcycle characterized in that a roller is fixedly disposed on the vehicle body near the toothed belt, and the roller presses the toothed belt by swinging displacement of a swing arm.