JPS6241155B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a motorcycle in which a rear wheel drive power unit disposed at an intermediate position between the front and rear wheels is covered with a cowling made of a thin plate.

In such a motorcycle, when a thin plate cowling is given special strength as a body frame, the cowling also serves as the body frame, simplifying the structure of the frame, and preventing vibrations of the cowling due to wind pressure etc. while driving. However, on the other hand, in order to increase the rigidity of the cowling, it is necessary to make the plate thicker or to install a large number of reinforcing members inside the cowling, which makes the structure of the cowling itself complicated. There is a problem in that it causes a significant increase in weight.

The present invention has been proposed in view of the above, and is capable of providing a cowling with the strength of a vehicle body frame without the above-mentioned problems, and also provides an excellent air cooling function for the heat dissipation section of the power unit. The purpose is to provide.

In order to achieve such an object, the present invention has the following features:
The rear wheel drive power unit, which is located between the rear wheels, is covered by a thin plate cowling that forms part of the vehicle body frame, and the left and right sides of the cowling are designed to give the cowling the strength of the vehicle body frame. The two side plates are firmly connected through the power unit, and an air inlet is opened in the front face of the cowling, and air outlets are opened in the left and right sides of the cowling, respectively.
Further, the left and right side plates of the cowling are connected through an air flow dividing guide plate that is housed in the cowling and defines a bifurcated ventilation path between the air inlet and the air outlet, and the heat dissipation of the power unit is connected to the air flow path. It is characterized by having a section.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings. In FIGS. 1 and 2, a motorcycle M has a body frame B having a head pipe 1 at the front end, a front wheel supported by the head pipe 1 via a steering shaft 2, It consists of a front fork Ff that supports Wf, a power unit P housed inside the vehicle body frame B, and a rear fork Rf that is pivotally connected to the power unit P and supports the rear wheel Wr on both sides at its free end. , their configurations will be sequentially explained next.

First, the vehicle body frame B includes a thin plate cowling 3 whose front end is fixed to the head pipe 1 and extends rearward and downward, and a seat stay 4 with a channel-shaped cross section that is separably connected to the rear end with a screw 5 and covers the upper part of the rear wheel Wr. As shown in FIG. 3, the cowling 3 includes a front plate 3a, left and right side plates 3.
b, 3b, ceiling plate 3c, and bottom plate 3d,
It is formed into a shell with an open rear surface, and has a streamlined shape as a whole. The front plate 3a of this cowling 3 has an air inlet 14, and both side plates 3b, 3
Air outlets 15 are respectively opened at b.

An airflow dividing guide 45 is provided within the cowling 3, thereby defining a bifurcated ventilation path within the cowling 3 for smoothly dividing the air that has entered the air inlet 14 into the left and right air outlets 15, 15. be done. The airflow dividing guide 45 also serves to strengthen the rigidity of the cowling 3 by connecting the side plates 3b, 3b of the cowling 3 to each other.

As clearly shown in FIGS. 4 and 5, a pair of radiators R, R are provided at both the left and right air outlets 15, 15.
are attached via elastic members 46, 46, and each of these radiators is composed of a pair of upper and lower water tanks 47, 48, and a plurality of flat water pipes 49, 49... that communicate with them. 49
The flat side surface of the cowling 3 is inclined outwardly and rearwardly of the cowling 3. Upper water tanks 47, 47 of both radiators
is connected to the cooling water outlet of the power unit P via a conduit 50, and the lower water tanks 48, 48 are connected to the same cooling water inlet via a conduit 51, respectively.

Therefore, while the vehicle is running, the synergistic effect of the ram pressure effect acting on the air inlet 14 and the suction effect acting on both air outlets 15, 15, as well as the air flow dividing guide plate 4.
5 generates a large airflow from the inlet 14 to the two outlets 15, 15 (see arrows in Figure 4), and these airflows pass around the flat water pipes 49, 49... of each radiator R. They can be effectively cooled. At that time, flat water pipe 4
9, 49... are inclined as described above, and do not prevent the airflow from being damaged. In this way, the cooling water cooled by both radiators R, R flows into the lower water tanks 48, 48.
After exiting and merging in a conduit 51 to cool the power unit P, the water is divided to the left and right by a conduit 50 and returned to the upper water tanks 47, 47, respectively.

Further, as clearly shown in FIG. 3, a horizontal guide rail 6 in the front-rear direction and a plurality of reinforcement/power unit support bosses 7 to 10 are welded to the inner surfaces of the left and right side plates 3b, 3b of the cowling 3. etc., and all of them face the side surface of the power unit P. Of these, the rearmost boss 10 has an occluded circular shape concentric with the output shaft 11 of the power unit P, and the bosses 7 to Bolt holes 7a to 10a are drilled at appropriate locations of 10, and a boss 1 having an occluded circular shape is provided.
A tool window 12 is opened in the center of 0.

The cowling 3 is formed integrally or suitably divided from lightweight materials such as light alloys and synthetic resins, and does not have practical strength by itself. Incidentally, reference numeral 13 denotes a patch member bonded to the inner surface of the cowling 3 in order to reinforce the area around the joint with the head pipe 1.

A fuel tank T is installed over the upper part of the cowling 3, and the sheen stay 4 extends rearward therefrom.
A seat S, on which the operator D sits astride, is attached to the seat.

The front fork F has a telescopic configuration, and is equipped with a steering handle 16 at its upper end and a headlight 17 at its front.

Next is the power unit P, which, as shown in FIG. 7, consists of a crankcase 18,
It has two multi-cylinder cylinder blocks 19 and 20 that protrude in a V-shape from the front of the case, and carburetors 22 and 23 of each block are housed in a V-shaped groove 21 between both blocks 19 and 20.

As shown in FIG. 6, a drive sprocket 25 is fixed to the output shaft 11 that penetrates the left side wall of the crankcase 18 and projects outward, and an adapter 26 that defines a housing h for the drive sprocket 25 is attached. Bolt 2 on the left side of the crankcase 18
It is fixed by 7. Further, an adapter 26' opposite the adapter 26 is fixed to the right side of the crankcase 18 by a bolt 27'. Pivots 28, 28' are removably screwed onto these shafts 28, 28 via bearings 29, 29' to the left side of the rear fork Rf.
The right proximal ends are each pivoted.

Additionally, brackets 30, 30 extending rearward are attached to both adapters 26, 26', respectively, with bolts 30, 30 extending rearward.
1 and 31, to which a rod-shaped step 32 is attached (FIGS. 1 and 7).

Furthermore, as shown in Fig. 6, the crankcase 1
Synthetic resin sliding members 33, 33 that can slide on the guide rails 6, 6 on the inner surface of the cowling 3 are fixed to both left and right side surfaces of the cowling 3 by bolts 34, 34, respectively.

Rear wheel Wγ pivotally supported at the rear end of rear fork R
is equipped with a driven sprocket 35, and a chain 36 is stretched between this and the driving sprocket 25. Therefore, the output of the power unit P can be transmitted from the output shaft 11 to the drive sprocket 25, the chain 36, and the driven sprocket 35 to drive the rear wheel Wγ.

Even if the left leg of the rear fork Rf is slightly deformed due to the tensile force acting on the chain 36 due to the above drive, the bearing of the pivot 28 on the output shaft 11 side is 29, a spherical bearing is particularly used. This ensures smooth vertical swing of the rear fork Rf.

Further, as mentioned above, the output shaft 11 and the pivot shafts 28, 2
8' are coaxially arranged, the distance between the driving and driven sprockets 25 and 35 does not change regardless of the swinging position of the rear fork Rf.
Therefore, the tension of the chain 36 can always be kept constant.

As shown in FIG. 7, the base end of a bifurcated tension link 37 that straddles the rear wheel Wr is pivotally supported 38 in the middle of the left and right legs of the rear fork Rf, and the front end of this link 37 At this position, the base end of the swing link 40 is pivoted 41 at the top of the crankcase 18 so as to be able to swing back and forth, and both links 37
and 40 are pivoted 39 to each other at their tips. Between the swing link 40 and the cylinder block 20,
Both ends of the shock absorber 42 and 43 are pivotally connected to each other, and a single shock absorber 44 with a suspension spring is interposed therebetween. In addition, the buffer 44
The fixed end, ie, the front end, may be connected to the upper rear end of the cowling 3.

The vertical swing of the rear fork Rf causes the swing link 40 to swing back and forth via the tension link 37, thereby giving the suspension spring-equipped shock absorber 44 an expanding and contracting action.
Therefore, the rear fork Rf is supported by one shock absorber 44 with a suspension spring, and its vertical swing is damped.

In assembling the motorcycle M, the cowling 3 and the power unit P are coupled in the following manner.

That is, first insert the power unit P into the cowling 3 from behind, set the sliding members 33, 33 in place while sliding them along the guide rails 6, 6, and then insert the power unit P into the cowling 3 on both the left and right outer sides. Tightening bolts 5 inserted into bolt holes 7a to 10a by
5 to 58, bosses 7 to 10 of both side plates 3b and 3b
Fix it to the power unit P. In this case, the occluded bosses 10, 10 are fixed to the adapters 26, 26' of the power unit P, respectively, and as a result, the side plates 3 of the power unit P and the cowling 3, especially around the pivot shafts 28, 28' of the rear fork Rf.
b and 3b are firmly fixed. In this way, the power unit P serves as a strength member that firmly connects the side plates 3b, 3b to each other and provides the cowling 3 with practical strength, that is, with strength as a vehicle body frame.

Furthermore, while driving, as shown in Fig. 1, the driver D places both feet on the steps 32,
At this time, both legs of the driver D are hidden behind the cowling 3, and combined with the streamlined shape of the cowling 3, the air resistance of the vehicle is extremely low.

Next, when the power unit P is connected to the cowling 3, when it is necessary to separate the rear fork Rf from the power unit P for maintenance when replacing the chain 36 and driven sprocket 35, the left and right parts of the cowling 3 must be separated. All you have to do is insert a tool through the tool windows 12, 12, pull out the pivot shafts 28, 28' from the respective bearings 29, 29', and disconnect the base end of the rear fork R from the adapters 26, 26'. Therefore, cowling 3
The power unit P coupled to the power unit P can easily and quickly carry out the above-mentioned maintenance work without having to separate it.

As described above, according to the present invention, the rear wheel drive power unit disposed at an intermediate position between the front and rear wheels is
The cowling is covered with a thin plate cowling that constitutes a part of the vehicle body frame, and the left and right side plates of the cowling are firmly connected via the power unit in order to give the cowling strength as a vehicle body frame. An air inlet is opened at the front surface, and an air outlet is opened at both the left and right sides of the cowling. Connect the left and right side plates of the cow rig,
Since the heat dissipation part of the power unit is arranged in the ventilation path, the sturdy power unit and the airflow dividing guide can also be used as reinforcing members for the left and right side plates of the thin plate cowling, significantly increasing the overall strength of the cowling. In this case, there is no need to increase the plate thickness of the cowling or install many reinforcing members inside the cowling, so a cowling with a simple structure, light weight, and extremely high rigidity can be obtained. can be effectively used as a part of the vehicle body frame, contributing to the structural simplification and weight reduction of the vehicle body frame, and is also effective in preventing vibrations of the cowling itself due to wind pressure and the like.

Furthermore, due to the ram pressure effect and suction effect at the air inlet and outlet, and the shunt guiding effect of the airflow dividing guide plate on the traveling wind, a large amount of traveling wind can be supplied to the heat dissipation section of the power unit. The power unit can be effectively cooled by the wind from the vehicle.

[Brief explanation of the drawing]

The drawings show one embodiment of the motorcycle of the present invention, in which Fig. 1 is an overall side view, Fig. 2 is a partially cutaway front view thereof, and Fig. 3 is a longitudinal sectional side view of the cowling, and the fourth, fifth, and Figure 6 is the same as in Figure 1.
FIG. 7 is a side view of the power unit and rear fork assembly. M...Motorcycle, P...Power unit, R
...Radiator, Wf...Front wheel, Wr...Rear wheel, 3
...Cowling, 3b...Side plate, 14...Air inlet, 15...Air outlet, 45...Air flow division guide plate.

Claims (1)

[Scope of Claims] 1. A rear wheel drive power unit disposed at an intermediate position between the front and rear wheels is covered with a cowling made of a thin plate that constitutes a part of the vehicle body frame, and this cowling is provided with a part that serves as the vehicle body frame. In order to provide strength, the left and right side plates of the cowling are firmly connected via the power unit, and an air inlet is opened in the front face of the cowling, and air outlets are opened in the left and right sides of the cowling. The left and right side plates of the cowling are connected through an air flow dividing guide plate that is housed in the air flow guide plate and defines a bifurcated ventilation passage between the air inlet and the air outlet, and a heat radiation section of the power unit is disposed in the ventilation passage. Motorcycles. 2. The motorcycle according to claim 1, wherein the heat radiator is a radiator connected to the power unit.