JPH01226486A - Power unit supporting structure for motorcycle - Google Patents

Abstract

PURPOSE:To ensure load clearance at the power unit supporting section by arranging a shock absorber in front of a vibration-isolating link. CONSTITUTION:In a structure for supporting a power unit 12 rollably on a body frame 2, upper the front section of the power unit 12 is supported on the body frame 2 through a vibration-isolating link 17, while the lower front section of the power unit 12 is coupled through a coupling link 22 and a shock absorber 25 to the body frame 2. The shock absorber 25 is positioned at longitudinally front side of a vehicle. Since there is no vertical interference between the vibration-isolating link 17 and the shock absorber 25, the shock absorber 25 can be arranged freely at an upper position, as required, in order to ensure load clearance. Since the shock absorber 25 is arranged at a high position, the shock absorber 25 can be protected from damage due to flying stone.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a power unit support structure suitable for scooter-type motorcycles, and in particular connects the front end of the power unit to the vehicle body frame via an anti-vibration link and a shock absorber. Regarding securing load clearance when supporting with

[Conventional technology]

Conventionally, the structure for supporting the power unit of a scooter-type motorcycle with the body frame is such that the front end of the power unit is swingably supported on the body frame, and there is a structure between the rear end and the body frame located above the power unit. It was common to install a buffer. In the body frame of this structure, a rear frame is essential as a strength member that supports the upper end of the shock absorber above the rear of the power unit.
There were limits to the miniaturization of the vehicle body frame, the height of the loading platform, and the height of the seat.

Therefore, as a support structure for a power unit that can solve the above-mentioned problem, there is a conventional support structure described in, for example, Japanese Patent Laid-Open No. 61-287889. This is an anti-vibration link at the top and bottom of the front of the power uni throat.

! It is connected to the vehicle body frame via a shock absorber, and these vibration isolating links and shock absorbers are positioned above and below.

According to this structure, the rear frame as the above-mentioned strength member is not required, and the size of the vehicle body frame and the height of the cargo platform can be reduced.

[Problem that the invention seeks to solve]

By the way, as shown in Figure 3 of the above-mentioned publication, the above-mentioned vibration isolation link is relatively large and requires a swinging space, so a correspondingly large installation space is required. . Therefore, when the vibration isolating link and the shock absorber, which also requires a relatively large space, are placed one above the other, as in the support structure described in this publication, it is important to consider the design in order to avoid interference between the two. In some cases, the shock absorber must be placed at a lower position, which inevitably results in a narrower load clearance. Furthermore, since the sliding parts and sealing parts of this shock absorber, such as the piston rod, are easily damaged by flying stones, etc., it is not preferable to arrange the shock absorber at a low position from this point of view as well.

SUMMARY OF THE INVENTION In view of the above-mentioned conventional problems, an object of the present invention is to provide a power unit support structure for a motorcycle that can achieve downsizing of the body frame, reduction of the cargo platform height, and ensure sufficient road clearance. .

[Means for solving problems]

The present invention provides a power unit support structure for a motorcycle for swingably supporting a power unit on a body frame, in which an upper part of the front part of the power unit is supported by the body frame via an anti-vibration link, and the front part of the power unit is The lower part of the vibration isolating link is connected to the vehicle body frame via a connecting link and a shock absorber, and the shock absorber is located on the front side of the vibration isolating link in the longitudinal direction of the vehicle.

[Effect]

According to the power unit support structure according to the present invention, the shock absorber is connected to the vehicle body frame via the connecting link, and the shock absorber is disposed in front of the vibration isolating link. This eliminates the problem of interference in the vertical direction of the shock absorber, and therefore the shock absorber can be freely placed in an upper position to ensure load clearance as required.

Furthermore, since the shock absorber can be placed at a high location, the problem of damage to the shock absorber due to flying stones and the like does not occur much.

〔Example〕

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

1 to 4 are diagrams for explaining a power unit support structure according to a first embodiment of the present invention.

In the figure, reference numeral 1 denotes a scooter type motorcycle to which the structure of this embodiment is adopted, and its body frame 2 is of a so-called underbone type having the following configuration. That is,
At the rear end of the front frame 2b, which extends downward from the steering shaft cylinder 2a and is bent rearward at the lower end, a pair of left and right rear frames 2c extend rearward from here and are further bent upward.
Fix the front end by welding. And this front and rear frame 2b
.

The lower bent portions of the rear frames 2C are connected to each other by a reinforcing pipe 2d, and the upper ends of the rear frames 2C are further connected by a loading platform frame 2e having a 0-shape in plan view.

A front fork 4 that pivotally supports the front wheel 3 at its lower end is supported on the steering shaft cylinder 2a, a steering handle 5 is fixed to the upper end of the steering shaft cylinder 2a, and a front cover 6 is provided around the steering shaft cylinder 2a. being surrounded. Further, a footrest plate 7 is mounted on the lower bent portion of the vehicle body frame 2, and the reinforcing vibe 2 of this footrest plate 7
The portion d is bulged upward to form a tunnel portion 7a. Furthermore, a seat 8 is provided above the rear frame 2C.
is mounted on the platform frame 2e, and a low-floor platform 9 is mounted on the platform frame 2e.
is formed. Further, the lower portions of the seat 8 and the loading platform 9 are surrounded by a rear cover 10.

A power unit 12 is arranged below the loading platform frame 2e. This power unit 12 is formed by integrating a forced air-cooled engine body 13 in which the cylinder and cylinder head are covered with a baffle cover, and a transmission case 14 that incorporates a belt-type continuously variable transmission.
A rear wheel 15 is pivotally supported at the rear end of the transmission case 14, and an air cleaner 16 for combustion air is mounted on the upper surface of the transmission case 14.

The upper part of the front end of the power unit 12 is pivotally supported via a vibration isolation link 17 to a support bracket lla fixed to the rear frame 2c so as to be able to swing up and down. As shown in FIG. 4, this anti-vibration link 17 has a cylindrical rubber bushing 1 attached to the front end of a plate-shaped link plate 18.
9a, a support hole 18a is formed in the rear end, a bottomed cylindrical holding cylinder 18b is fixed to the upper part, and the cylinder 18
A rubber damper 19b having a built-in buffer spring 20 is housed in the rubber damper 19b. This buffer spring 20 is used when the main stand is erected or when driving on a rough road.
C and restricts the upward swinging of the power unit 12. The rubber bush 19a is attached to a pair of support brackets lla and llb fixed to the rear frame 2C.
The support hole 18a is supported by a support pin 21b via a rubber bush 14c on a support bracket 14a integrally formed with the transmission case 14. Further, the support bracket lid is formed with a spacing part 1)e. This causes the two to come into contact with each other during a jump or the like, thereby restricting the downward swinging of the power unit 12.

Further, a lower portion of the front end portion of the power unit 12 is connected to an upper bent portion of the rear frame 2C via a connecting link 22. The left connecting links 22 are rotatably connected to each other.

The first of the right pair. Consisting of second links 23 and 24, the rear end of the first link 23 is pivotally supported by a support platen 14b integrally formed with the transmission case 14, and the approximately central portion of the second link 24 is fixed to the rear frame 2C. support bracket I
It is pivotally supported by lb.

Also, a buffer 2 is provided between the upper ends of the second link 24.
The rear ends of 5 are connected. This buffer 25 is arranged substantially horizontally within a tunnel portion 7a formed in the footrest 7, and its front end is pivotally supported by a support platen zic fixed to the front frame 2b. In this way,
The shock absorber 25 is located in front of the vibration isolating link 17, and both are arranged substantially linearly in the front-rear direction.

Next, the effects of this embodiment will be explained.

In this embodiment, the upper and lower parts of the front end of the power unit 12 are supported by the vehicle body frame 2 via the anti-vibration link 17, the connecting link 22, and the shock absorber 25, respectively.
There is no need to extend the rear frame to the rear end of the vehicle at a relatively high place, unlike when installing a shock absorber between the rear frame and the rear end of the transmission case. The size can be reduced by 2C, and the seat 8 can be placed at a lower location if necessary. Furthermore, the loading platform frame 2e can be lowered to form the loading platform 9 at a lower location, making it easier to load and unload cargo.

If the front end of the power unit is supported on the vehicle body frame by vibration isolating links and shock absorbers placed above and below, as in the conventional structure described above, the shock absorbers must be placed low to avoid interference between the two. , the road clearance may become narrower. On the other hand, in this embodiment, the buffer 2
5 is placed in front of the vibration isolating link 17 by interposing the connecting link 22, there is no need to consider vertical interference between the two, and therefore the shock absorber 25 can be freely placed at a high location. , the load clearance is not narrowed by the shock absorber 25. In this embodiment, the first link 23 of the connecting link 22 is located below, but this link 23 is smaller than the shock absorber 25. Since the load clearance is not narrowed due to this, and since the connecting link 22 is simply a connection of plates, there is almost no risk of damage from flying stones or the like.

In addition, in this embodiment, since the shock absorber 25 is disposed in the tunnel portion 7a formed by bulging the center portion of the footrest plate 7 upward, the foot of the footrest plate 7 on which the occupant places both feet. The mounting portion 7b can be set to the same height as the conventional one. In other words, since the shock absorber 25 is arranged above the footrest 7b, there is no unnecessary downward protrusion (and the same load clearance as before can be secured in this footrest 7 portion).

5 and 6 are diagrams for explaining a second embodiment of the present invention, and this embodiment is an example in which the footrest can be made flat like in a conventional scooter type motorcycle. .

In the figure, the same reference numerals as in FIG. 1 indicate the same or corresponding parts, and in this embodiment, the second link 24 of the connecting link 22 has an oval shape. A shock absorber 25 is disposed approximately vertically between the rear end of the upper side of the second link 24 and the support bracket 1) c fixed to the upper end of the rear frame 2c. The shock absorber 25 is the vibration isolation link 1
It is located in front of 7. In addition, the buffer 25 of this embodiment
is eccentric to the left in the vehicle width direction when viewed from above, and the connecting link 22 is also configured by bending the first link 23 to the left in accordance with this.

Similar to the first embodiment, this embodiment also has the effect of ensuring road clearance, reducing the seat height and cargo platform height, and reducing the size of the vehicle body frame.
Furthermore, since the shock absorber 25 is disposed substantially vertically along the rear frame 2c, there is no need to provide a tunnel section on the footrest 7, and this has the effect of making it flat.

Further, in this embodiment, since the shock absorber 25 is eccentric in the vehicle width direction, the power unit 12 can be positioned that far forward, and the distance between the axes can be shortened as necessary. Incidentally, when the shock absorber 25 is disposed on the axis of the vehicle, the power unit 12 must be disposed in the e direction in order to avoid interference between the shock absorber 25 and the exhaust pipe 13a from the engine body 13.

FIG. 7 shows a modification of the second embodiment, in which the loading platform can be further lowered. In FIG. 0, the same reference numerals as in FIG. 5 indicate the same or equivalent parts, In this embodiment, the engine main body 13 is arranged horizontally, and the air cleaner 16 is arranged in a corner-shaped space formed by the outer wall surface of the engine main body 13 and the front wall surface of the transmission case 14. There is.

This embodiment has the same effects as the second embodiment, and also has the effect that the height of the power unit 12 is lowered, and as a result, the loading platform 9 and the seat 8 can be further lowered.

〔Effect of the invention〕

As described above, according to the power unit support structure for a motorcycle according to the present invention, since the shock absorber is placed in front of the vibration isolating link, the body frame can be downsized, the seat and cargo platform can be lowered, and the power unit support part can be lowered. This has the effect of ensuring road clearance.

[Brief explanation of the drawing]

1 to 4 are diagrams for explaining the support structure of a power unit according to a first embodiment of the present invention, in which FIG. 1 is a left side view thereof, and FIGS. II-II
4 is a partially sectional side view of the anti-vibration link, FIG. 5 is a left side view of the second embodiment of the present invention,
FIG. 6 is a plan view thereof, and FIG. 7 is a left side view showing a modification of the second embodiment. In the figure, 1 is a scooter type motorcycle, 2 is a body frame, 12 is a power unit, 13 is an engine body, 1
4 is a transmission case, 14a and 14b are support brackets (upper and lower parts of the front part of the power unit), 17 is a vibration isolation link, 22 is a connection link, and 25 is a shock absorber. Patent applicant: Yamaha Motor Co., Ltd. No. 2, Fig. 3, Fig. 4

Claims (1)

[Claims] (1) In a motorcycle power unit support structure for swingably supporting a power unit formed by integrating an engine body and a transmission case containing a transmission mechanism on a vehicle body frame, the upper part of the front part of the power unit is vibration-proofed. The power unit is supported by the vehicle body frame via a link, and the lower part of the front part of the power unit is connected to the vehicle body frame via a connecting link and a shock absorber, and the shock absorber is located in front of the vibration isolating link in the longitudinal direction of the vehicle. A power unit support structure for a motorcycle, characterized by: