JPS58112888A - Suspension system for power unit - 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 suspension system for a power unit in a unit swing type motorcycle or the like.

A unit swing type suspension system is known in which a power unit consisting of an engine transmission case, drive wheels, etc. is pivoted to the frame side and configured to be able to swing up and down. There is a disadvantage in that the impact acting on the drive wheels is transmitted to the vehicle body frame, and this has been attempted to be improved by interposing an elastic body such as rubber at the pivot joint, but this is not sufficient.

Therefore, the applicant previously proposed a structure in which the vehicle body side and the power unit are connected with a link to suppress the propagation of vibrations and shocks to the vehicle body side, but by providing the links in the front and rear direction, the power unit is placed at the rear. As a result, the length of motorcycles, etc. in the front and rear direction will become slightly longer,
It is preferable that the vibration-proof upper link be long, but if it is made long, the length in the front-rear direction becomes even longer. Therefore, further improvement is desired.

The present invention has been made to improve the above-mentioned problems, and its purpose is to pivotally attach the lower part of the link to the vehicle body through a rubber bushing, etc., the link extends to the road, and the upper part of the link is attached to the vehicle body using a rubber bushing, etc. It pivots to the front of the power unit through the link, and swings around the pivot point of the power unit to absorb engine vibration, impact from the wheels, reaction force, etc., making it more compact without increasing space by using the lower part of the link as the fulcrum. To provide a power unit suspension device in which the link length can be set to a sufficiently long length and the vibration damping effect can be improved.

Next, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows a scooter as an example of a motorcycle 1,
A front wheel 4 supported by a front fork 3 is provided at the lower front part of the vehicle body 2, a handle 5 connected to the front wheel 4 is provided at the upper part of the front part, a low floor type floor 6 is provided at the middle part, and a front wheel 4 supported by a front fork 3 is provided at the upper part of the vehicle body 2. is provided with a seat 7.

The main frame 8 is formed of a pipe material with a head tube (not shown) fixed to the front end and has omitted sides.
As shown in the figure, a downward channel type cross plate 9 is horizontally fixed to the rear end directly below the seat 7, and the cross plate 9 is horizontally fixed. The lower ends of the rear frame 10.10 are joined, and the rear 7 frame 10.10 has left and right members parallel to each other, stands upwardly, forms an inverted shape, and extends rearward and upwardly. The middle part of the cross plate 9 in the left and right direction is formed into a reverse opening type so as to surround the upper rear end and the top of the main frame 8, and is formed into a flat stopper part 1 on the top of the main frame.
1, and on the other hand, the left and right members of the rear frame f0.
A stopper stay 12 is provided above the main frame between 10 and 10 and is spaced apart in the height direction by a cross member 10 and the like horizontally suspended between the main frame and the stopper stay 12 which faces the stopper part 11 which is biased to one side from the center of the vehicle body.

A bolt forming a support shaft 13 is inserted into the rear end of the main frame 8 so as to pass through the lower part of the rear frame on both sides thereof. The horizontal frame is fastened to the frame members on both sides, and the lower part of the link 15 is pivotally connected to the support shaft 13. The link 15 consists of left and right members 15.1 and 152, each of which has an intermediate or lower part facing inside the lower part of the left and right frame members io and io, and a collar that penetrates in the left and right direction at the lower part of the members 151 and 152. 16, the collar 16 is provided with collars 171L and 17b on the inner and outer diameter parts, and a rubber bush 17 with a rubber 17c interposed therebetween is fitted and pivoted around the support shaft 13, and the rubber bush 17 is attached to the link 15.
A preload is applied so as to bias it counterclockwise in FIG. The link 15 extends upward, diagonally upward and backward in a substantially dogleg shape in the embodiment, with a collar 18 horizontally suspended between the upper parts, and a power unit 1 consisting of an engine, a transmission case, etc.
Inner and outer diameter portions 20a are provided in the left and right through holes 19b provided in the boss portions 19a protruding to the left and right of the front portion of 9.

A rubber bushing 20 with a rubber 20c baked therein is fitted between the rubber bushings 20b, and a bolt forming a support shaft 21 is passed through the collar 18 horizontally between the inner diameter portions of the rubber bushing 20. The front part of the unit is pivotally mounted, and the rubber bushing 20 provides a preload in the counterclockwise direction in FIG. A rear wheel 22 serving as a driving wheel is supported on the rear side of the power unit 19, and a rear wheel unit is interposed between the rear part of the power unit 19 and the rear part of the rear frame as is known in the art.

A reinforcing cross member 23 made of a cross member or the like is horizontally fixed between the intermediate parts of the links 15, and a stopper stay 24 is provided extending forward in the intermediate part of the cross member 23, and stopper stays are provided above and below this. Rubbers 25 and 26 are protruded, and the rubber 25 faces the stopper stay 12, and the rubber 26 faces the stopper part 11, and when the angle <-25° 26, the stoppers 12 and 11 are offset to the left and right, and the rubber They are offset to the left and right for ease of installation.

Next, to explain its functions and effects in detail, the vibrations of the engine forming the engine unit are absorbed by swinging around the lower support shaft 13 of the link 15, and the vibrations of the engine are absorbed by the rubber bushings interposed between the upper and lower supports. However, since the link 15 is provided vertically, even if the link length is increased, the lower unit will not move rearward due to the layout.
It is possible to make the link length longer while bringing the power unit closer to the frame as much as possible in front, making it possible to make the front and rear more compact, and setting the link longer to increase the vibration suppression effect. is supported at the top of the link, the minimum ground clearance of the power unit can be maintained high, and since the link is not hanging down or horizontal, the ground clearance of this can also be increased, and when considering interference from the road surface, etc., it is possible to maintain a high minimum ground clearance of the power unit. It is also advantageous, especially by arranging the link below the front of the engine, which can also function as an engine guard. Reaction force from the road surface that acts from the rear wheels when driving, shock,
The reaction force from the rear cushion unit is the power unit 1.
It is absorbed by the combined movement of the swing of the upper fulcrum 21 of the link 9 and the swing of the link 15 from the lower fulcrum. By the way, vibrations and shocks on the power unit side cause the link 15 to swing back and forth about the lower fulcrum 13 in FIG. Due to the movement of the link, the stop rubber 25°□ 26 collides with the upper or lower stopper 2.11, which is absorbed by the elastic deformation of the rubber 25.26, and the excessive impact on the link is alleviated at this portion.

As is clear from the following, according to the present invention, the power unit and the vehicle body side are pivotally connected by a link, and the length of the link is set to be long while suppressing the length in the longitudinal direction, further improving the vibration isolation effect.
It is possible to improve the absorption and mitigation function of shocks, etc., and this can be achieved with a simple structure.As the link faces the front lower part of the power unit, it can be protected as an engine guard, and the power unit and link can be seen from the road surface. It has many advantages, such as being able to protect them by arranging them at high positions.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is a side view of a motorcycle, FIG. 2 is a side view of a main part of a suspension section by a link, and FIG. 3 is a cross-sectional view taken along line 3-3 in FIG. FIG. 4 is an explanatory perspective view of the same. In the drawing, 8.9 is the vehicle body, 15 is a link, 13°21 is an upper and lower support shaft, and 19 is a power unit. Patent Applicant Honda Motor Co., Ltd. Agent Patent Attorney 2 1) Part of the patent

Claims (1)

[Claims] In a power unit suspension system in which the vehicle body and the power unit such as the engine and transmission case are pivotally connected via a link, the lower part of the link is pivotally connected to the vehicle body via a rubber bush, etc., and the link is erected above the road. extended,
A suspension device for a power unit, characterized in that the upper part of the link is pivotally connected to the power unit via a rubber bush or the like.