JPH0567475B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an engine support structure in a power unit swing type motorcycle, particularly an engine,
The power unit, such as the crankcase and transmission case, is integrally constructed and supported swingably with respect to the vehicle body frame together with the rear wheels, and a link member that swings in a direction approximately perpendicular to the main axis of inertia of the engine is used. An improved engine support structure in which one end is pivotally connected to the vehicle frame and the other end is pivotally connected to both outer sides of the engine forming the power unit, and the rear part of the power unit that supports the rear wheels is connected to the vehicle body via a shock absorber. It is related to.

[Prior art] The power system, such as the engine, crankcase, and transmission case, is assembled as one unit, and the front part of this is pivotally connected to the vehicle body frame, and the rear part supports the rear wheel, while a shock absorber is installed on the frame side. A power unit swing type motorcycle is known in which the power unit is connected to the rear wheel via a rear wheel, and the power unit swings integrally with the rear wheel using a pivot point on the frame side as a fulcrum to perform a damping motion.

[Problems to be Solved by the Invention] The above-described power unit swing type motorcycle engine can be mounted and supported on the body frame side by extending a bracket from the body frame side, and attaching a support portion protruding toward the engine side to the bracket. It is pivoted with a pin. In conventional engines of this type, the transmission case and the like are placed horizontally, but the cylinders are vertically erected, that is, vertically or substantially vertically. Therefore, the main axis of inertia of the engine is vertical or approximately vertical, and the main excitation force due to the reciprocating inertia of the piston, etc., and the rotational inertia of the crankshaft, etc. is transmitted to the frame as vibration in the vertical direction, which causes the vehicle body to The frame vibrates in the vertical direction, impeding ride comfort.
Furthermore, if you park the vehicle with the stand raised and leave the engine running, the vehicle body frame may vibrate vertically due to the vertical vibrations caused by the engine support, and as a result, the vehicle body frame may move slightly up and down. There are also. Furthermore, with the above conventional means, vibrations and shocks to the rear wheels from the road surface are absorbed by only rotation around the engine pivot point, so the propagation rate of vibrations and shocks through the frame is high, resulting in improved riding comfort. The engine side is almost rigidly supported in this direction, so if there is a shock from a protrusion from the front to the rear wheel while driving, the rear wheel will be Even if a damping motion is performed, the direction is the vertical direction, and such impact cannot be effectively suppressed. Therefore, the rear wheels move up and down while escaping to the rear, and are unable to follow the impact, resulting in poor ride comfort.

Therefore, in order to improve the above problem, it has been proposed to interpose a hanger bracket that functions as a link between the bracket on the frame side and the engine side, and to support the engine at two points. According to this, the above problem can be alleviated somewhat. However, the engine is still installed vertically, and its main axis of inertia is in the vertical direction.
Vibration propagation in the frame cannot be effectively blocked. Further, the links are also arranged horizontally, and the tracking ability of the rear wheels in the front-rear direction is not good. Therefore, the above-mentioned conventional problems have not yet been solved.

In addition, a power unit in which the engine is placed horizontally has been proposed in order to improve the problems of the above-mentioned vertically installed engines, but in this case, since the engine side is pivoted to the frame side at one point, this pivot The rubber bushing interposed in the branch is required to have both the functions of vibration isolation and load support for the power unit, and therefore it has to be a moderate support that satisfies both vibration isolation and load support to some extent. Therefore, it is not possible to obtain sufficient vibration damping properties, and it is also difficult to obtain sufficient load support for the power unit. Furthermore, it is difficult to obtain a satisfactory followability of the power unit in the longitudinal direction, and the above problem cannot be solved satisfactorily.

Therefore, it may be possible to pivot one end of a link member that can swing along a direction substantially perpendicular to the main axis of inertia of the engine to the vehicle body frame, and the other end to both outer sides of the engine forming the power unit. However, for those that have steps and cover members on the sides of the bracket on the vehicle body frame side, there is a problem of interference with link members and swing regulating parts.To avoid this, link members and swing regulating parts should be If it is configured outside the bracket, there is also the problem that the vehicle body expands in the width direction.

[Means for Solving the Problems] In order to solve the above problems, the present invention provides an engine,
The power unit, such as the crankcase and transmission case, is integrally constructed and supported swingably with respect to the vehicle body frame together with the rear wheels, and a link member that swings in a direction approximately perpendicular to the main axis of inertia of the engine is used. In a motorcycle in which one end is pivotally connected to the vehicle body frame side and the other end is pivotally connected to both outer sides of the engine forming the power unit, and the rear part of the power unit that supports the rear wheel is connected to the vehicle body side via a shock absorber. A pair of left and right brackets are provided facing each other on the frame side, and a pair of left and right links are provided inside these brackets with a space formed between them.One end of this link is pivotally connected to the bracket, and the other end is connected to the engine. A stopper is provided on the vehicle body frame side within the width surrounded by both the brackets and is fixed integrally with the bracket, and the stopper is integrally fixed to the bracket and swings integrally with the link. It is characterized in that the regulating means can come into contact with the stopper via a cushion rubber by a predetermined swing of the link.

[Embodiment] Next, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings. This will reveal further objects and advantages of the invention.

FIG. 1 is a schematic side view showing an example of a motorcycle in which the present invention is implemented, FIG. 2 is an enlarged side view of the engine support section with main parts in cross section, and FIG.
It is a sectional view taken along line 3-3 in the figure.

In FIG. 1, a motorcycle 1 is shown as a small-sized motorcycle with a small displacement, and a frame 2 is made of pipe material and includes a main frame 2a extending diagonally downward and rearward from a head tube 3, and a main frame 2a extending diagonally upward from the lower end of the main frame 2a. The frame 2 is made up of posts 2b extending rearward, each of which is connected at a joint 4 at its lower end, and the frame 2 is generally V-shaped in its entirety. head tube 3
supports the front fork 5 extending downward, which supports the front wheel 6, and upper and lower bridges 7 that support the upper part of the front fork 5.
A handle 8 is provided on the top. post 2b
A seat 10 is provided at the upper end via a box-shaped support member 9, and a rear carrier 11 extends behind the support member 9 and the post 2b, and a fuel tank 12 is installed within the rear carrier 11.

A pair of substantially inverted L-shaped brackets 13, 13 are hung down on the left and right sides of the V-shaped joint 4 of the frame 2, facing the outside of the cylinder 22 of the engine 21.
a hangs diagonally downward, and the upper part 13b protrudes rearward approximately horizontally at a position higher than the engine 21 and apart. Such brackets 13, 13
Steps 14 project from the left and right through a bar installed between the tip portions 13a of the steps.

20 is a power unit, and the unit 20 includes an engine 21, a crank case 23, and a transmission case 24.
The cylinder 22 of the engine 21 is set so that its axis is horizontal or approximately horizontal, and the crankcase 23 is continuous with the cylinder 22 of the engine 21. The transmission case 24 is disposed in the extending direction of the axis of the cylinder 22, that is, in the horizontal or substantially horizontal direction. Therefore, the reciprocating motion of the piston (not shown) housed in the cylinder 22 is horizontal or approximately horizontal, and the direction of the engine's motion inertia, including the rotational inertia of the crankshaft, is in the same direction. That is, the main axis of inertia is in the longitudinal direction with respect to the two-wheeled vehicle, and the direction of the main excitation force generated by the engine is horizontal or approximately horizontal.

At the base of the cylinder 22 of the power unit 20 or at the tip of the crankcase 23, support protrusions 25, 25 are provided to protrude from the left and right above the base. The protrusions 25, 25 are spaced apart in the width direction, and are each provided with a mounting hole 26 extending across the width.

On the other hand, the left and right brackets 1 on the frame side
A link 27 is pivotally installed at 3 and 13. link 27
A pair of pieces 28, 28 are suspended downward from a pair of brackets 13, 13, which are provided at a large distance from each other in the width direction of the vehicle body so as to face the sides of the cylinder 22 of the engine 21, and are opposed to the brackets 13, 13. The upper part of each bracket is attached to the end of the upper part 13b of the bracket with bolts and nuts 29, which are pins. A collar 30 is fixed to the top of each link piece 28, 28,
A rubber bush 34 is interposed between the inner diameter portion of this 30 and the bolt 29, with collars 31 and 32 interposed on the inner and outer diameter portions, and a rubber bushing 33 whose inner and outer diameter portions are baked and integrated. , pieces 28, 2 forming the link 27 via the rubber bush 34.
8 is pivotally connected to brackets 13, 13.

The link 27 is suspended vertically downward from the pivot joint 29, and the lower part of each piece 28, 28 of the link 27 is bent inward in the width direction as shown in FIG. A collar 35 having a shape of 35 mm is installed across the engine 21 and is fixedly installed, while a bolt 3
A collar 35 fixed to the lower end of the link 27 is fitted to a partial outer periphery between the protrusions 25 and 25 on the engine side supported by a bolt 36. A rubber bush 41 is interposed between the mounting holes 26, 26 and the bolt 36, with collars 38, 39 interposed on the inner and outer diameter portions, and a rubber bushing 40 whose inner and outer diameter portions are baked and integrated. be done.
One end of the bolt 36 is screwed into a nut 37 to stop the bolt 36.

The upper pivot portion 29 and the lower vertical portion 36 of the link 27 are set to be on the same vertical line, and the cylinder 2
Since 2 is horizontal, it forms a right angle, that is, the main axis of inertia of the engine is horizontal, and the engine is supported by the link 27, which is supported at two points that are perpendicular to this and on the same vertical line. In the engine support structure constructed in this way, the link 2 is attached to the horizontal protrusion of the upper part 13b of the brackets 13, 13.
The upper end of the link 27 is pivotally connected to provide sufficient ground clearance to the power unit and to increase the bank angle of the vehicle body as much as possible. By being pivotally connected between the left and right protrusions 25, 25 of the power unit, sufficient rigidity is maintained against moments (particularly torsional moments) that act on the power unit due to swinging of the power unit. There is.

In the above, each plate 2 forming the link 27
A stopper 43 is provided in front of the upper pivot point 29 of 8 and 28 to engage with a stopper 43 to be described later.
An extending portion 28a extending to the upper and lower positions is formed. In this way, the extending portion 28a is provided to increase the width of the link 27 and contribute to improving its rigidity. A stopper 43 is protrudingly provided on the side surface between the upper and lower pivot points of the link 27 and on the front side adjacent to the link 27, and this 43 has a cushion rubber 44 on its outer periphery.
is installed surrounding the rubber 44, and a clearance S is normally secured between the outer periphery of the rubber 44 and the swing restricting means 42 on the link side.

The rear part of the power unit 20, whose front part is suspended and pivotally supported by the engine 21, is attached to the rear wheel 15.
The supporting protrusion 20a protruding from the upper part of the shock absorber 16 and the lower end of the shock absorber 16 forming the rear action unit are pivotally connected 17, and the upper end of the shock absorber 16 is provided on the post 2b on the frame side. The rear part of the power unit 20 is supported on the frame side.

As described above, a link mechanism similar to a parallelogram having the frame, power unit, link, and shock absorber as its constituent elements is constructed, and functions as a parallel link.

Next, to explain its operation, the main axis of inertia of the engine 21 is horizontal, and the direction of its main excitation force is the direction shown by the arrow in FIG. On the other hand, the engine 21 is pivotally supported on the bracket 13 by the link 27 at two points 36 and 29, and the link 27 is perpendicular to the engine, so that the inertial mass of the engine in the longitudinal direction is at the fulcrum 29 of the link 27. It is converted into a rocking motion in the front and back direction with the fulcrum at . Therefore, engine vibrations are absorbed by the pivoting of the link 27, and vibration components in the direction of the link 27 do not occur or become extremely small. In this way, the propagation of engine vibrations to the frame is reduced and suppressed as much as possible, and the propagation of engine vibrations to the vehicle body is blocked. In addition, since engine vibration is absorbed by the pivoting of the link arranged at right angles to the engine, vibration to the link,
Vibration to the mounting bracket is also reduced and suppressed, its own vibration and resonance can be prevented, and vibration of the frame caused by secondary vibration can also be prevented. Therefore, even when the vehicle is parked with the main stand raised while the engine is running, the vibration of the vehicle body is extremely small, preventing movement during parking, and ensuring stable parking.

In addition, since the above link and the buffer form a parallel link, and the main axis of inertia of the engine is horizontal,
The vibrations of the engine are absorbed by the shock absorber by its rocking motion, and therefore the propagation of vibrations from the shock absorber to the vehicle body side is also prevented, and the shock absorber can be arranged so as to form a link similar to a parallel link. , there are no problems with the installation layout of the shock absorber like in the past,
This increases the degree of freedom in arrangement and is convenient in terms of design.

Furthermore, since the structure is configured to form parallel links as described above, the rear wheels can follow this movement in the forward and rearward directions extremely smoothly, and even if the vehicle interferes with a bump on the road while driving, the rear wheels will follow this movement. It moves forward and backward, and together with its buffering function, it can effectively buffer and attenuate vibrations and slow impacts to the vehicle body. In this way, the ride comfort during driving is significantly improved compared to the conventional one, in combination with the above.

In addition, since the rubber bushes 34, 41 are interposed in the pivot parts 29, 36, these parts absorb and attenuate vibrations caused by pivoting and vibration components of the engine, thereby further increasing the above-mentioned vibrations.

As described above, in this embodiment, the pivot points 29 and 36 of the link 27
is on the vertical line, and therefore the engine 21
The relationship with the main axis of inertia has been described as being at a right angle, but the above link may be installed at a slight inclination in the front and rear directions, especially rearward.The above engine is approximately horizontal, and the link is also at a predetermined angle. , a minus sign is provided to make it approximately vertical, and the angle may be changed to the extent that it does not interfere with the above functions.

Furthermore, the power unit 2 due to the buffering effect of the rear wheel 15
The forward and backward movements of 0 are followed and absorbed by the swinging of the link 27 around the fulcrum 29, but the amount of this swinging is determined by the swinging restriction means 42 and stopper 43 of the link 27.
This collision is regulated by the collision with the cushion rubber 44, and this collision is absorbed and damped by the rubber 44.

4 and 5 show a second embodiment of the present invention.

In this embodiment, the pivot portion on the engine side is changed, and the other parts are the same as above, so the same parts are given the same reference numerals.

That is, the bolt 36 that forms the lower pivot connection of the pieces 28, 28 of the link 27 and the protrusion 2 on the engine 21 side.
Ball bearings 141 are interposed between the mounting holes 26 of 5 and 25 to support the load in the radial direction. The inner race 139 of the bearing 141 is laterally supported by washers 140, 140, and the outer race 138 is supported by a step 26a provided on the side of the mounting hole 26. By doing this, the lateral rigidity of the pivot support part is improved, and the rotation of the pivot part is smoothed by the action of the bearing, and the relative movement of this part with the link 27 is suppressed against vibrations in the front and rear directions of the engine. to improve the vibration prevention effect.

6 and 7 show a third embodiment of the present invention, in which in addition to the engine side pivot part of the second embodiment, the vehicle body side pivot part of the link is also supported by bearings, and the basic structure is as described above. Since it is the same as the above, the same parts are given the same reference numerals.

That is, bearings 134 that support the load in the radial direction are interposed between the upper collars 30 of the pieces 28, 28 of the link 27 and the bolts 29, respectively, and the inner race 132 of the bearing 134 is supported on the side by washers 133, 133. However, the outer lace 131 has a stepped portion 30a provided on the side of the collar 30.
I support it. Then, a stopper collar 142 is fixed to the front of the pieces 28, 28, and this is fitted into a stopper rubber bushing 144 which is pivotally supported by a bolt 143 protruding from the bracket 13.
44 is provided with a space 144a in the swinging direction of the link,
This makes it easier to bend the bushing. By doing so, the swinging movement of the link 27 by the pivot portion 29 is smoothed, and the above-mentioned effect can be enhanced, and the stopper 144 is designed as described above in order to smooth the swinging movement.

In the third embodiment, it goes without saying that the pivot portion on the engine side may be a rubber bush.

[Effects of the Invention] As is clear from the above, according to the present invention, the effect of propagating engine vibration toward the vehicle body is achieved by the link member that is swingable along a direction substantially perpendicular to the main axis of inertia of the engine forming the power unit. suppression, reduction,
In motorcycles designed to absorb vibrations and shocks from the road surface while driving and improve riding comfort, a pair of left and right links are installed inside a pair of left and right brackets facing each other on the body frame side, and a link is used to control their swinging. Because of the arrangement of the stoppers, if there are other members such as steps or cover members outside the bracket, they can be brought close to the bracket without worrying about interference with the links or stoppers. This allows the vehicle body to be made slim without expanding in the width direction.

Furthermore, a stopper is provided within the width surrounded by both brackets on the vehicle body frame side and is fixed integrally with the bracket, and a swing regulating means that swings integrally with the link is configured to stop the cushion by a predetermined swing of the link. Since the stopper can come into contact with the stopper through the rubber, the forward and backward movements of the power unit are followed and absorbed by the swinging movement about the fulcrum of the link, but the amount of this swinging is controlled by the swinging control means of the link. This is regulated by the collision between the rubber and the cushion rubber of the stopper, and the collision is absorbed and attenuated by the cushion rubber.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is a schematic side view of a motorcycle, FIG. 3-3 line sectional view, FIG. 4 shows a second embodiment of the present invention and is similar to FIG. 2, FIG. 5 is a similar diagram to FIG. 3, and FIG. 3 is a diagram similar to FIG. 2, and FIG. 7 is a diagram similar to FIG. 3. In the drawings, 1 is a motorcycle, 2 is a body frame, 13 is a bracket, 15 is a rear wheel, 16 is a shock absorber, 20 is a power unit, 21 is an engine, 2
2 is a cylinder, 23 is a crankcase, 24 is a transmission case, 27 is a link, 28a is an extension part, 42
is a regulating means, and 43 is a stopper.

Claims (1)

[Scope of Claims] 1. A power unit including an engine, a crankcase, a transmission case, etc. is integrally constructed, and is swingably supported with respect to a vehicle body frame together with a rear wheel, in a direction substantially perpendicular to the main axis of inertia of the engine. One end of the link member, which can swing along the rear wheel, is pivotally connected to the vehicle body frame side, and the other end is pivotally connected to both outer sides of the engine that forms the power unit, and the rear part of the power unit that supports the rear wheels is connected to the vehicle body via a shock absorber. In a motorcycle connected to the side, a pair of left and right brackets are provided facing each other on the body frame side, a pair of left and right links are provided inside the brackets with a space formed between them, and one end of the link is connected to the bracket. At the same time, the other end is pivotally connected to the left and right sides in the width direction of the engine, and furthermore, a stopper fixed integrally with the bracket is provided within the width surrounded by both the brackets on the vehicle body frame side, and the link An engine support structure for a motorcycle, characterized in that a rocking regulating means that swings integrally with the link can come into contact with the stopper via a cushion rubber by a predetermined rocking of the link.