JPS5930594B2 - Motorcycle drive unit suspension system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic motor vehicle in which a drive unit formed by integrally connecting an engine and a transmission case that houses a transmission device from the engine to a rear axle is swingably suspended relative to a vehicle body. The present invention relates to a drive unit suspension system for a two-wheeled vehicle, and in particular to a structure of the drive unit suspension system that increases torsional rigidity to improve maneuverability and stability of the motorcycle and exhibits a sufficient vibration-proofing effect.

Conventionally, motorcycles in which a drive unit that integrates an engine and a transmission case is swingably suspended from the vehicle body have a structure in which the weight of the drive unit is supported by a connecting link and an elastic support, and the drive unit is A structure has been proposed in which the elastic support body is used to dampen the movement of the connecting link that swings around the horizontal axis of rotation due to the main excitation force.

However, with such a structure, it was not possible to prevent vibrations from being transmitted to the vehicle body via the elastic support, and it was not possible to obtain a sufficient vibration-proofing effect. However, in order to solve the above-mentioned problems, the present invention eliminates the need for the elastic support. Therefore, it is an object of the present invention to provide a drive unit suspension system for a motorcycle that eliminates vibration transmission to the vehicle body and has a simple structure.According to the present invention, the engine and the transmission device from the engine to the rear axle are housed. In a drive unit suspension system for a motorcycle in which a drive unit integrally configured with a transmission case is swingably suspended with respect to a vehicle body, horizontal horizontal axes are provided on each of the vehicle body side and the front part of the drive unit, These horizontal axes are connected by a connecting member with high torsional rigidity that is rotatably attached to each axis, and the rear cushion, whose lower end is attached to the drive unit, is tilted forward and its upper end is attached to the vehicle body. Mount the drive unit so that the resultant force of the weight of the drive unit, rear axle load reaction force, rear cushion reaction force, and ground contact drive force acts as a tensile force on the connecting member, and the main excitation force of the engine is applied at right angles to the connecting member. A suspension system for a drive unit of a motorcycle is proposed, which is characterized in that the drive unit is moved in a certain direction.

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

FIG. 1 is a diagram showing the main parts of a motorcycle having a drive unit suspension system of the present invention. In FIG. 1, a drive unit 14 is swingably suspended on a vehicle body 12 of a motorcycle.

The drive unit is constructed by integrally combining an engine 16 and a transmission case 18, and inside the transmission case there are a transmission device from the engine 16 to the rear axle 20,
For example, a chain transmission mechanism is housed there. Note that reference number 22 indicates a rear wheel, and 24 indicates a driver seat supported by the vehicle body (frame) 12. A lateral horizontal shaft 26 is provided at the front of the drive unit 14, and a lateral horizontal shaft 28 on the vehicle body side is provided at a position opposite to this shaft.

These horizontal axes are connected by a connecting link 30 as a connecting member with high torsional rigidity. each horizontal axis 26;
Each of 28 constitutes a pivot shaft that allows rotation about one axis relative to the connecting link 30. Further, the vehicle body 12 is provided with a stopper 32 for restricting movement of the connecting link. A rear suspension 34 is attached to the vicinity of the rear axle of the drive unit 14 and extends upward and forward from there at an angle, and its upper end is attached to the vehicle body (frame) 12.

Therefore, in the drive unit suspension system of the present invention, the center of gravity of the drive unit 14 is C. G. The rotational moment formed around the horizontal axis 26 on the drive unit side of the connecting link by the resultant force of the weight 01 acting on the rear axle load reaction force W1 the rear cushion reaction force P and the driving force T acting on the rear wheel contact area is substantially Therefore, the connecting link is arranged in such a positional relationship that only the force on the straight line connecting the axes of the horizontal shafts 26 and 28, that is, only the axial force, acts on the connecting link.

In FIG. 1, the weight (gravity) Q of the drive unit can be decomposed into a component Q1 acting as an axial force on the connecting link 30 and a component Q2 forming a moment about the horizontal axis 26.

Similarly, rear axle load reaction force w, rear cushion reaction force P
And the ground contact driving force T also has components W1, P1, and T that act as axial forces on the connecting link 30, and the shaft 26, respectively.
Components W2, P2 and T2 forming moments around
It can be decomposed into According to the drive unit suspension system of the present invention, the sum of the moments about the shaft 26 formed by each of the components Q2, W2, P2, and T2 is substantially zero. Therefore,
The connecting link 30 has the axial force forming components Ql, W,, Pl
Only an axial force (tensile force) equal to the resultant force of and T acts, and no moment acts. Furthermore, the direction of the main excitation force of the engine 16 incorporated in the drive unit is shifted so that it substantially coincides with the direction perpendicular to the connecting link 30, that is, the direction perpendicular to the straight line connecting the horizontal axes 26 and 28. There is.

Various structures can be adopted as specific structures for the lateral horizontal shafts 26, 28 and the connecting link 30 with high torsional rigidity that connects these shafts, an example of which is shown in FIGS. 2 and 3. show. Figures 2 and 3 show the temperature of the car body (
Brackets 42 are fixed to the frame 12 at two locations on the left and right by welding or the like, and each is provided with a horizontal horizontal shaft 28 having the same axis.

On the other hand, a lateral horizontal shaft 26 is also provided at the front of the drive unit 14 . These horizontal axes are connected by a connecting link 30 having high torsional rigidity. The connecting link is formed by welding or otherwise fixing bracket portions 30A on both left and right sides and a rod member 30B for connecting these bracket portions to each other and improving torsional rigidity. The rear part of the connecting link is rotatably attached to the front part of the drive unit 14 via two left and right rubber bushes 44 which also serve as anti-vibration rubber.

In addition, the front part of the connecting link connects to the horizontal shaft 28 on the vehicle body side via radial ball bearings 46 provided at two locations on the left and right.
It is mounted rotatably relative to the The bracket 42 is provided with an upper stopper 48 and a lower stopper 50 for restricting the interlocking movement of the connecting link 30 within a predetermined range. FIG. 4 is a diagram showing another embodiment of the attachment part of the connecting link 30, and this embodiment/example uses a bush-like sliding bearing instead of the radial ball bearing 46 of the embodiment of FIGS. 2 and 3. 52, and the other parts are substantially the same as those in FIGS. 2 and 3.

FIG. 5 is a diagram showing still another embodiment of the attachment part of the connecting member 30, in which both the horizontal shaft 26 on the 1 drive unit 14 side and the horizontal shaft 28 on the vehicle body side are rubber bushes. It is connected to each of the drive unit 14 side and the vehicle body side via a vibration isolating rubber 54.

Each rubber bush 54 has a structure in which rubber is baked between inner and outer steel rings, and is press-fitted into a cylindrical hole formed on the vehicle body side and the first drive unit side, and the inner ring is attached to the connecting link 3.
It is tightened to the 0 side. Above, specific examples of each attachment part of the connecting link 30 have been explained with reference to FIGS. 2 to 5, but the structures of these attachment parts include rubber bushes 44, 54,
Ball bearings (rolling bearings) 46, sliding bearings 52, etc. can be selected and used as appropriate! RuO
Still other embodiments of the connection between the front part of the drive unit 14 and the vehicle body 12 are shown in FIGS. 6 and 7.

In this embodiment, a relatively large diameter horizontal horizontal hole 62 is formed in the front part of the drive unit 14, and its axis 26A corresponds to the drive unit side elongated shaft 26 in FIGS. 1 to 5. It is located in a position where A coupling member 60 that is slidable and rotatable in the circumferential direction is fitted into the horizontal hole 62 . Therefore, a horizontal horizontal axis 28A parallel to a position within the connecting member 60 and eccentrically located a predetermined distance toward the vehicle body from the axis 26A thereof.
A second horizontal hole 64 is formed. The axis 28A of the second horizontal hole 64 is provided at a position corresponding to the vehicle body side horizontal axis 28 in the embodiment shown in FIGS. 1 to 5. A shaft 66 that slides and rotates relatively is fitted into the second horizontal hole 64, and both ends of the shaft are attached to the bracket 42 of the vehicle body 12. Therefore, in the embodiments of FIGS. 6 and 7, the center of gravity C of the drive unit 14 shown in FIG. G. The rotational moment formed around the shaft center 26A on the drive unit side by the resultant force of the weight Q1 acting on the rear axle load reaction force W, the rear cushion reaction force P, and the driving force T acting on the rear wheel contact area becomes substantially zero. Thus, the direction of the main excitation force of the engine 16 is shifted so that it substantially coincides with the direction perpendicular to the straight line connecting the shaft center 26A and the vehicle body side shaft center 28A.

In other words, the connecting member 60 having the second horizontal hole 64 at an eccentric position has substantially the same function as the connecting link 30 of the embodiment of FIGS. 1-5. The connecting member 60 having the second horizontal hole at an eccentric position is preferably made of synthetic resin, but may be made of other suitable materials. Since the present invention has the configuration and operation described above, the following effects can be obtained.

Tilt the rear cushion 34 forward and drive unit 1
4, weight Q, rear axle load reaction force w, rear cushion reaction force P
Since the resultant force of the rear wheel drive force T and rear wheel driving force T acts as a tensile force on the connecting member 30, the connecting member can rotate about the horizontal axis in order to support the weight of the drive unit and provide vibration isolation, as in a conventional suspension system. It is not necessary to suppress the vibration with an elastic support, and the continuous member 30 can be left in a free state.Moreover, the main excitation force of the engine 16 is transferred in a direction perpendicular to the straight line connecting the attachment parts of the connecting members, and the engine is applied. Since almost all of the vibration force acts as a rocking excitation force on the connecting member 30, the connecting member can swing freely, and therefore, an extremely excellent vibration-proofing effect can be exhibited.

At the same time, since a member with high torsional rigidity is used as the connecting member, it is possible to prevent the drive unit and the rear wheel from lateral displacement and twisting with respect to the vehicle body, and it is possible to maintain the maneuverability and stability of the motorcycle. .

Furthermore, as mentioned above, the structure can be simplified since the conventional elastic support is not required.

[Brief explanation of the drawing]

FIG. 1 is a side view showing the main parts of a motorcycle having a drive unit suspension system of the present invention, FIG. 3 is a sectional view taken along the line ■-■ in FIG. 2, FIG.
6 is a cross-sectional view of a main part showing still another embodiment of a connecting member mounting part, FIG. 7 is a cross-sectional view of a main part showing still another embodiment of a connecting member and its mounting part, and FIG. Middle line ■−■
FIG. In each figure, the same reference numbers indicate the same or corresponding parts, 12... Vehicle body (frame), 14...
...Drive unit, 16...Engine,
18...Transmission case, 20...Rear axle, 22...Rear wheel, 26, 26A...
Drive unit side horizontal horizontal axis, 28, 28A...
. . . Vehicle body side lateral horizontal axis, 30, 60 . . . Connecting member, 62 . . . Horizontal hole, 64 . . . Second horizontal hole, respectively.

Claims (1)

[Scope of Claims] 1. A drive unit suspension for a motorcycle in which a drive unit integrally configured with an engine and a transmission case that houses a transmission device from the engine to the rear axle is swingably suspended relative to the vehicle body. In the device, horizontal horizontal axes are provided on the vehicle body side and the front of the drive unit, and these horizontal axes are connected by connecting members with high torsional rigidity that are individually attached to be rotatable with respect to the axes. , the rear cushion whose lower end is attached to the drive unit is tilted forward and its upper end is attached to the vehicle body, and the resultant force of the drive unit weight, rear axle load reaction force, rear cushion reaction force, and ground contact driving force is applied to the connecting member. 1. A drive unit suspension device for a motorcycle, characterized in that the device acts as a tensile force and transfers the main excitation force of the engine in a direction perpendicular to the connecting member. 2. In the above item 1, a relatively large-diameter horizontal hole is formed at the horizontal horizontal axis position of the front part of the drive unit, and a connecting member is rotatably fitted into the horizontal hole, and the connecting member is rotatably fitted into the horizontal hole. A second horizontal hole is formed in the member at a position that is eccentric toward the vehicle body side from the axis thereof and corresponds to the horizontal axis position on the vehicle body side, and the shaft is rotatably fitted into the second horizontal hole. A drive unit suspension system for a motorcycle, characterized in that the connecting member is attached to a vehicle body via.