WO2014016793A1

WO2014016793A1 - Motorcycle

Info

Publication number: WO2014016793A1
Application number: PCT/IB2013/056100
Authority: WO
Inventors: Jose Luis Belil Creixell
Original assignee: Jose Luis Belil Creixell
Priority date: 2012-07-25
Filing date: 2013-07-25
Publication date: 2014-01-30
Also published as: ES1077541Y; ES1077541U; EP2877393A1

Abstract

Motorcycle (1), comprising an engine (2), a swing arm (4) coupled by one end (3a) to a drive wheel (3) and by its other end to an axle (5) articulated to the chassis (6) of the motorcycle (1), and suspension means including a shock absorber (7) provided with a spring, a cylindrical body (7a) and a piston (7b), said cylindrical body (7a) of the shock absorber (7) being articulated in a lower point (8) of the chassis (6) under the swing arm (4), and with its piston (7b) oriented towards the upper part of the chassis (6) and articulated to one end (9a) of a rocker link (9), said rocker link (9) being articulated by its other end (9b) to the upper part of the swing arm (4) and articulated in turn by an intermediate point (9c) to the end of a connecting rod (10), said connecting rod (10) in turn being articulated to a lower part of the chassis (6) and to a support (2a) of the engine (2), so that said shock absorber (7) can be compressed according to a resulting force directed towards the lower area of the chassis (6) of the motorcycle (1), thanks to the action of the rocker link (9) and the connecting rod (10) when the swing arm (4) moves upward.

Description

MOTORCYCLE

The present invention relates to a motorcycle, preferably a motorcycle for use on irregular ground.

Background of the invention

Motorcycles are known comprising an engine, a drive wheel, a swing arm coupled by one end to said drive wheel and by its other end to a pivotable shaft solidly joined to a lower point of the motorcycle chassis, transmission means between the engine and the drive wheel and suspension means.

Said suspension means include a spring and a shock absorber provided with a cylindrical body and a piston alternatively displaceable therein, said cylindrical body being articulated in an upper point of the motorcycle chassis and with said piston articulated to one end of a rocker link, said rocker link being articulated by its other end to the swing arm and articulated in turn by an intermediate point to the end of a connecting rod which in turn is articulated to a lower part of the chassis. Said connecting rod makes it possible to guide the rocker link according to a radial movement with respect to the chassis, and in turn the rocker link can be rotated over itself with respect to the intermediate point of articulation with the connecting rod, thus allowing the transmission of the movement between the swing arm and the shock absorber piston. The cylindrical body of the shock absorber is articulated in an upper point of the chassis above the swing arm, with its piston oriented towards the lower part of the chassis, and said rocker link being articulated in the lower part of the swing arm, so that said shock absorber can be compressed according to a resulting force directed towards the upper area of the motorcycle chassis when the swing arm moves upward.

Nevertheless, this type of shock absorption systems have the drawback that they need two considerably rigid structures in the chassis to withstand the stresses generated in this structural configuration, which makes the weight of the structure increase and also makes the manufacturing costs more expensive. Furthermore, due to the fact that the cylindrical body of the shock absorber is anchored in an upper area of the chassis, an elevation occurs of the centre of gravity of the motorcycle, due to the greater weight of the cylindrical body with respect to the piston and the increase in weight of the reinforced structures to withstand these loads, which is not desirable.

One of the reinforcement structures is situated in the lower part of the chassis, where the connecting rod is articulated, since the connecting rod is the element that receives the greatest stresses generated during the operation of the suspension means, in the order of 5000 kg; whilst the other reinforcement structure is situated in the upper part of the chassis where the cylindrical body of the shock absorber is articulated, withstanding stresses in the order of 1000 kg.

Another drawback of the shock absorption means described is that it is difficult to achieve greater progressiveness due to their structural configuration.

The known shock absorbers also have the drawback that when an impact occurs caused, for example, by a considerable irregularity on the ground, the stroke of the shock absorber reaches the limit causing an impact in the rider's ankles and a possible injury, as well as an impact to the motorcycle as a whole. To avoid or reduce this effect, a rubber or similar element is used disposed between the piston and the cylindrical body of the shock absorber, but in practice it has been verified that this is not an entirely effective solution.

Description of the invention

The objective of the motorcycle of the present invention is to resolve the drawbacks in motorcycles known in the state of the art, providing a motorcycle with more efficient suspension means and with a simpler, lighter and cheaper structural configuration.

The motorcycle of the present invention is of the type comprising an engine, a drive wheel, a swing arm coupled by one end to said drive wheel and by its other end to an axle articulated in an upper point of the motorcycle chassis, transmission means between the engine and the drive wheel, and suspension means including a shock absorber provided with a spring, a cylindrical body and a piston alternatively displaceable therein, said cylindrical body being articulated to the motorcycle chassis and with said piston articulated to one end of a rocker link, said rocker link being articulated by its other end to the swing arm and articulated in turn by an intermediate point to the end of a connecting rod which in turn is articulated to a lower part of the chassis, and is characterized in that the cylindrical body of the shock absorber is articulated in a lower point of the chassis under the swing arm, and with its piston oriented towards the upper part of the chassis, said rocker link being articulated in the upper part of the swing arm, and the connecting rod being articulated to the chassis and to a support of the engine, so that said shock absorber can be compressed according to a resulting force directed towards the lower area of the motorcycle chassis, thanks to the action of the rocker link and the connecting rod when the swing arm moves upward.

In this way, the fact that the suspension means are mounted in the lower part of the motorcycle chassis allows that the upper part of the chassis is relieved of stresses and of the weight caused by said suspension means, also achieving a simpler structural configuration of the chassis.

More specifically, on the one hand, it avoids the upper anchoring of the shock absorber, which allows the centre of gravity of the motorcycle to be positioned in a lower position, eliminating the disposal of reinforcement structures in the upper part of the chassis, since the stresses in this upper area of the chassis are transmitted downward through the swing arm and are easily distributed due to the arc shape of the chassis in this area, in comparison with the suspension systems known in the state of the art, whose stresses are transmitted upward.

Furthermore, the reinforcement structure in the lower part of the chassis is considerably lightened as the loads change from 5000 kg to 1000 kg approximately. This is due to the shock absorber being anchored in this area, instead of anchoring the connecting rod as occurs in the suspension systems known in the state of the art. In the present invention, the connecting rod is anchored to a common axle of the chassis and the engine support, so that the engine mass helps to withstand the stresses of the lower anchoring of the connecting rod. In consequence, this configuration considerably reduces the stresses in the lower part of the chassis.

Preferably, two connecting rods are disposed respectively on each side of the shock absorber, and symmetrically mounted with an inclination with respect to an substantially vertical axle, so that the distance between its upper ends articulated to the rocker link is less than the distance between its lower ends articulated to the engine support. This inclined configuration of the connecting rods provides greater robustness to withstand the stresses generated.

Advantageously, each connecting rod is manufactured from a deformable flexible material by way of leaf spring, capable of elongating a certain distance when the stroke of the shock absorber reaches the limit. In this way, due to the deformable configuration of the connecting rods, when the stroke of the shock absorber reaches the limit due to an impact or irregularity on the ground, the rear wheel can rise a few centimetres more thanks to said leaf spring effect of the connecting rods, which avoids an impact from occurring on the rider's ankles as well as on the motorcycle as a whole and avoiding fatigue in the materials thereof. According to an embodiment of the present invention, the transmission means between the engine and the drive wheel comprise a first driving chain which gears with a power pinion coupled to the engine with a first crown coaxial with said pivotable shaft of the swing arm, and a second driving chain which directs the power from the pivotable shaft of the swing arm to the axle of the drive wheel through another two crowns mounted on the respective axles cited.

Advantageously, the first driving chain is mounted on one side with respect to the longitudinal axis of the motorcycle, whilst the second driving chain is mounted on the other side with respect to the longitudinal axis of the motorcycle. Brief description of the drawings

In order to facilitate the description of all the aforementioned, drawings are attached wherein, diagrammatically and only by way of non-limiting example, a practical embodiment of the motorcycle of the invention has been represented, wherein: figure 1 is a diagrammatic partial side view of the motorcycle according to the present invention; figure 2 is an enlarged view of the suspension means in resting position, according to the right side of the motorcycle; figure 3 is a similar view to figure 2 according to the left side of the motorcycle; figure 4 is an enlarged view of the suspension means in the compression position, according to the right side of the motorcycle; figure 5 is a cross-section of the suspension means; figure 6 is a diagrammatic view of one of the connecting rods, showing its original length illustrated in continuous line, and its extended length illustrated in broken line when the stroke of the shock absorber reaches the limit; figure 7 is a diagrammatic view of the motorcycle of the present invention, showing the approximate forces withstood by the structure and components of said motorcycle when the rear suspension reaches the limit of its stroke; and figure 8 is a diagrammatic view of a conventional motorcycle of the state of the art showing the approximate forces withstood by the structure and components of said motorcycle when the rear suspension reaches the limit of its stroke.

Description of a preferred embodiment

As can be observed in figures 1 to 4 and 7, the motorcycle 1 of the present invention comprises an engine 2, a drive wheel 3, a swing arm 4 coupled by one end 3a to said drive wheel 3 and by its other end to an axle 5 articulated in an upper point of the motorcycle 1 chassis 6, transmission means between the engine 2 and the drive wheel 3 and suspension means.

Said suspension means include a shock absorber 7 provided with a spring, a cylindrical body 7a and a piston 7b alternatively displaceable therein, said cylindrical body 7a being articulated in a lower point 8 of the motorcycle chassis 6 under the swing arm 4, and with its piston 7b oriented towards the upper part of the chassis 6.

The piston 7b of the shock absorber 7 is articulated to one end 9a of a rocker link 9, said rocker link 9 being articulated by its other end 9b to the upper part of the swing arm 4 and articulated in turn by an intermediate point 9c to the end of a connecting rod 10. Said connecting rod 10 in turn is articulated to a lower part of the chassis 6 and to a support 2a of the engine 2, so that said shock absorber 7 can be compressed according to a resulting force directed towards the lower area of the motorcycle chassis 6, thanks to the action of the rocker link 9 and the connecting rod 10 when the swing arm 4 moves upward. In this way, the fact that the suspension means are mounted in the lower part of the motorcycle chassis, allows that the upper part of the chassis is relieved of the stresses and the weight caused by said suspension means, also achieving a simpler structural configuration of the chassis.

Figures 2 and 3 respectively show the right and left side of the motorcycle 1 , showing the swing arm 4 in the lower position with the suspension means at rest, whilst figure 4 shows said swing arm 4 in the position displaced upward with the suspension means actuated. For a better understanding, a comparison is made between the motorcycle 1 of the present invention diagrammatically illustrated in figure 7 and a conventional motorcycle 1 ' of the state of the art diagrammatically illustrated in figure 8. In the conventional motorcycle 1 ' (see figure 8), the cylindrical body 7a' of the shock absorber T is articulated in an upper point 8' of the chassis 6' above the swing arm 4', with its piston 7b' oriented towards the lower part of the chassis 6', and the rocker link 9' being articulated in the lower part of the swing arm 4', so that said shock absorber 7' can be compressed according to a resulting force F3' directed toward the upper area of the motorcycle chassis 6' when the swing arm 4' moves upward by the force F1 .

In this case, two considerably rigid structures 6a', 6b' are required in the chassis 6' to withstand the forces generated with this structural configuration, which increases the structure weight and also makes the manufacturing costs more expensive.

One of the reinforcement structures 6a' is situated in the lower part of the chassis 6'. The connecting rod 10' is articulated in a lower part 2a' of said reinforcement structure 6a'. The connecting rod 10' is the element that receives the greatest stresses F4' generated during operation of the suspension means, in the order of 5000 kg. The other reinforcement structure 6b' is situated in the upper part of the chassis 6' where the cylindrical body 7a' of the shock absorber 7 is articulated, withstanding stresses F3' in the order of 1000 kg. In figure 8, the length of the F4' vector is approximately five times greater than the length of the F3' vector in order to illustrate the difference in magnitude of stresses. On the other hand, due to the fact that the cylindrical body 7a' of the shock absorber 7' is anchored in an upper area of the chassis 6', there is an elevation in the centre of gravity of the motorcycle 1 ', due to the greater weight of the cylindrical body 7a' with respect to the piston 7b' and the increase in weight of the reinforced structure 6b' to withstand these loads, which is not desirable.

Unlike in the motorcycle 1 of the present invention (see figure 7), it avoids the upper anchoring of the shock absorber 7, which allows that the centre of gravity of the motorcycle 1 is situated in a lower position, eliminating the disposal of reinforcement structures in the upper part of the chassis 6, since the stresses F2 in this upper area of the chassis 6 are transmitted upward through the swing arm 4 and are easily distributed due to the arc shape that the chassis 6 has in this area, in comparison with the suspension system of the motorcycle 1 ' of the state of the art the stresses F3' of which are transmitted upward.

Furthermore, in the motorcycle 1 of the present invention, the reinforcement structure in the lower part of the chassis 6 is considerably lightened as the loads change from 5000 kg (F4') to 1000 kg (F3) approximately. This is due to the fact that the shock absorber 7 is anchored in this area, instead of anchoring the connecting rod 10 as occurs in the suspension systems known in the state of the art. In the present invention, the connecting rod 10 is anchored to a common axle of the chassis 6 and the support 2a of the engine 2, so that the mass of the engine 2 helps to withstand the stresses F4 of the lower anchoring of the connecting rod 10. In consequence, this configuration considerably reduces the stresses in the lower part of the chassis 6. Again, the vector lengths in figure 7 illustrate the differences in stresses F3 and F4.

According to another aspect of the present invention, and as can be observed in figure 5, two connecting rods 10 are disposed respectively on each side of the shock absorber 7, and symmetrically mounted with an inclination with respect to an substantially vertical axle, so that the distance between its upper ends articulated to the rocker link 9 is less than the distance between its lower ends articulated to the support 2a or the engine 2. This inclined configuration of the connecting rods 10 provides a greater robustness to withstand the stresses generated. Each connecting rod 10 is manufactured from a deformable flexible material by way of leaf spring, capable of elongating a certain distance when the stroke of the shock absorber 7 reaches the limit (absorption limit). In figure 6 the deformation that the connecting rod 10 may undergo can be observed, from its original length L1 illustrated in continuous line, to its extended length L2 illustrated in broken line when the stroke of the shock absorber 7 reaches the limit.

In this way, due to the deformable configuration of the connecting rods 10, when the stroke of the shock absorber 7 reaches the limit due to an impact or irregularity on the ground, the rear wheel 3 can rise a few centimetres more thanks to said leaf spring effect of the connecting rods 10, which avoids an impact from occurring on the rider's ankles as well as on the motorcycle as a whole and avoiding fatigue in the materials thereof.

Making reference to figures 2 and 3, the transmission means between the engine 2 and the drive wheel 3 comprise a first driving chain 1 1 which gears with a power pinion 12 coupled to the engine 2 with a first crown 13 coaxial with said pivotable shaft 5 of the swing arm 4, and a second driving chain 14 which directs the power from the pivotable shaft 5 of the swing arm 4 to the axle 3a of the drive wheel 3 through other two crowns mounted on the respective axles 3a, 5 cited.

According to this embodiment, the first driving chain 1 1 is mounted on one side with respect to the longitudinal axis of the motorcycle 1 (see figure 3), whilst the second driving chain 14 is mounted on the other side with respect to the longitudinal axis of the motorcycle 1 (see figures 2 and 4).

It must be indicated that in the present description, the term "driving chain" must be understood to include any transmission element suitable for motorcycles and in no case must be understood as limiting for determining the scope of the present invention, defined in the attached claims.

For reasons of simplicity, the other components of the motorcycle of the present invention are not described, since they are conventional and do not form part of the present invention.

Despite the fact a specific embodiment of the present invention has been referred to, it is evident that for a person skilled in the art that numerous variations and modifications can be introduced in the motorcycle described, and that all the details mentioned can be replaced by other technically equivalent ones, without departing from the scope of protection defined by the attached claims.

Claims

Motorcycle (1 ), comprising an engine (2), a drive wheel (3), a swing arm (4) coupled by one end (3a) to said drive wheel (3) and by its other end to an axle (5) articulated in an upper point of the chassis (6) of the motorcycle (1 ), transmission means between the engine (2) and the drive wheel (3), and suspension means including a shock absorber (7) provided with a spring, a cylindrical body (7a) and a piston (7b) alternatively displaceable therein, said cylindrical body (7a) being articulated to the chassis (6) of the motorcycle (1 ) and with said piston (7b) articulated to one end (9a) of a rocker link (9), said rocker link (9) being articulated by its other end (9b) to the swing arm (4) and articulated in turn by an intermediate point (9c) to the end of a connecting rod (10) which in turn is articulated to a lower part of the chassis (6), characterized in that the cylindrical body (7a) of the shock absorber (7) is articulated in a lower point (8) of the chassis (6) under the swing arm (4), and with its piston (7b) oriented towards the upper part of the chassis (6), said rocker link (9) being articulated in the upper part of the swing arm (4), and the connecting rod (10) being articulated to the chassis (6) and to a support (2a) of the engine (2), so that said shock absorber (7) can be compressed according to a resulting force directed towards the lower area of the chassis (6) of the motorcycle (1 ), thanks to the action of the rocker link (9) and the connecting rod (10) when the swing arm (4) moves upward.

Motorcycle (1 ), according to claim 1 , wherein two connecting rods (10) are disposed respectively on each side of the shock absorber (7), and symmetrically mounted with an inclination with respect to an substantially vertical axle, so that the distance between its upper ends articulated to the rocker link (9) is less than the distance between its lower ends articulated to the support (2a) of the engine (2).

Motorcycle (1 ), according to claim 2, wherein each connecting rod (10) is manufactured from a deformable flexible material by way of leaf spring, capable of elongating a certain distance when the stroke of the shock absorber (7) reaches the limit.

Motorcycle (1 ), according to claim 1 , wherein the transmission means between the engine (2) and the drive wheel (3) comprise a first driving chain (1 1 ) which gears with a power pinion (12) coupled to the engine (2) with a first crown (13) coaxial with said pivotable shaft (5) of the swing arm (4), and a second driving chain (14) which directs the power from the pivotable shaft (5) of the swing arm (4) to the axle (3a) of the drive wheel (3) through another two crowns mounted on the respective axles (3a, 5) cited. Motorcycle (1 ), according to claim 4, wherein the first driving chain (1 1 ) is mounted on one side with respect to the longitudinal axis of the motorcycle (1 ), whilst the second driving chain (14) is mounted on the other side with respect to the longitudinal axis of the motorcycle (1 ).