WO2010015987A1

WO2010015987A1 - Rotating mechanical transmission for a tilting system of the wheels of a vehicle with three or four wheels

Info

Publication number: WO2010015987A1
Application number: PCT/IB2009/053359
Authority: WO
Inventors: Luciano Marabese
Original assignee: Marabese Design S.R.L.
Priority date: 2008-08-04
Filing date: 2009-08-03
Publication date: 2010-02-11
Also published as: ITMI20081454A1

Abstract

The present invention relates to a wheel tilting system for vehicles with three or more wheels in which at least two wheels are set alongside on the same axle. The wheel tilting system according to the present invention comprises at least one oscillating arm (2) for each wheel and at least one mechanical transmission (3, 3a, 3b, 4) adapted to connect said arms (2) to one another and adapted to transmit the motion of oscillation of said arms (2) into the motion of rotation of a connection rod (3) about its axis. The tilting system according to the present invention it particularly simple to be implemented and thus cost-effective as well as operatively reliable. Furthermore, such a system have very small dimensions and light weight.

Description

ROTATING MECHANICAL TRANSMISSION FOR A TILTING SYSTEM OF THE WHEELS OF A VEHICLE WITH THREE OR FOUR WHEELS

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FIELD OF THE INVENTION The present invention relates to a tilting system of the wheels of a vehicle with three or four wheels, in which at least two wheels are set alongside each other on the same axle and are tilting, allowing the vehicle to lean with respect to the ground when turning. PRIOR ART The vehicles of the type considered herein and already known in the field are, for example, three-wheel motorcycles, in which the two wheels paired on the same axle generally are the front wheels, and quads or ATVs (all terrain vehicles) vehicles with four wheels which are used not only as transportation means or for leisure activities, but are increasingly more commonly used as working vehicles, for transporting loads and for towing.

Furthermore, vehicles provided with wheels coupled on the same axle capable of leaning towards the interior of the curve when turning are included in these categories of vehicles with three or more wheels. This feature, achieved by more or less evolved wheel tilting mechanisms, increases vehicle performance, especially when turning at high speed, where the vehicle alignment is strongly influenced by the weight distribution of the vehicle-driver whole, in particular by the position of the centre of gravity of such a system and the gyroscopic effect which is obtained due to the rolling angle of the vehicle. Systems for mechanically controlling the vehicle alignment, in particular the tilting of the wheels paired on the same axis, are known in the field. These mechanical systems include the use of a leverage system which connects the hubs of the two paired wheels so as to allow their tilting when turning. The wheel inside the curve raises with respect to the vehicle and the one outside the curve lowers, thus practically allowing the vehicle to lean with respect to the ground or to roll. Vehicles with three wheels to be used on roads are known, in which the front wheels, paired on the same axle, are swinging.

In the case of vehicles with four wheels, in order to allow the vehicle to lean when turning as a motorcycle, the rear wheels must also include a tilting system.

A rear wheel tilting system is known from the prior art, e.g. from international patent application WO97/27071.

Systems of this type include the presence of two arms connected to the wheel hubs of the vehicle and hinged to the frame, the tilting system including, for example, a mechanical system for controlling the movement of the arms, e.g. by means of a spring system or by using a rocker or the like. In all cases, these tilting systems of known type have some drawbacks.

A first drawback relates to the dimensions of the tilting control system which occupies a considerable space.

In the case of systems which control the rear wheel tilting, the problem is more felt because the system occupies indeed a zone of the vehicle, normally the rear zone under the saddle, which is usually intended for accommodating the engine and/or is provided with accessory or crash helmet compartments.

A second drawback relates to the degree of construction complexity of these devices, which determines the production and maintenance economy thereof.

SUMMARY OF THE INVENTION Therefore, it is the main task of the present invention to solve the above-described drawbacks in relation with the dimensions and the construction complexity of the wheel tilting systems of the known type.

In the scope of this task, it is the object of the present invention to provide a wheel tilting system of a vehicle which has a highly simple construction in addition to highly small dimensions.

It is a further object of the present invention to provide a tilting system which incorporates a tilting arrest system, e.g. for when travelling at low speeds or when parking the vehicle.

This task and these and other objects which will be more apparent below are achieved by a tilting system of the wheels of a vehicle comprising at least one arm for each wheel and at least one mechanical transmission adapted to connect said arms together and adapted to convert the motion of oscillation of said arms into the motion of rotation of a connection rod about its own axis.

BRIEF DESCRIPTION OF THE DRAWINGS Further features and advantages of the present invention will be more apparent from the following detailed description provided by way of non-limitative example and illustrated in the accompanying drawings, in which: figure 1 shows a diagrammatic side view of a tilting system according to the present invention under a straight travel condition of the vehicle; figure 2 shows another side view of the tilting system in figure 1 , with the vehicle under a leaning condition when turning; figure 3 shows a front view, from the rear towards the front of the vehicle, of the tilting system according to the present invention again with the vehicle under a turning condition; figure 4 shows a top view of the tilting system according to the present invention under a straight travel condition of the vehicle.

DETAILED DESCRIPTION OF THE INVENTION

According to a preferred embodiment of the present invention illustrated by way of non-limitative example in the mentioned figures from 1 to 4, the tilting system 1 according to the present invention comprises at least one arm 2a, 2b for each wheel, a first end of each of said arms 2a, 2b being hinged to the frame 5 of the vehicle, and the opposite end being connected to the hub of said wheel.

Each arm 2a, 2b is then associated with a suspension 4a, 4b, respectively.

The suspension 4a, 4b is advantageously an element, e.g. substantially cylinder- shaped in the embodiment described herein, which comprises both a spring component obtained by means of a spiral spring, and a hydraulic damping component.

The spring and hydraulic shock absorber set will be referred to as "suspension" in the following description, and the suspension element, or simply the suspension, is represented in the figures by reference numeral 4a, 4b. Again with reference to the accompanying drawings, each of the suspensions 4a and 4b is associated with one of said arms 2a, 2b by means of a hinge. A first end of said suspension 4a, 4b is thus hinged to said arm 2a, 2b, while its opposite end is instead hinged to a bar 3a, 3b, respectively, firmly connected to a rod 3. Said rod 3 is in turn associated with the frame 5 of the vehicle, to which it will be connected by means of specific bearings so that it is free to rotate about its axis. The connection of the rod 3 to the frame is not shown in the drawings.

With reference, for example, to figure 4, rod 3 thus connects the suspensions 4a, 4b to each other by means of the arms 3a, 3b. The rod 3 is placed in a substantially transversal direction, but positioned with respect to the longitudinal axis of the vehicle according to an angle so that, when considered on a horizontal plane as that shown in figure 3, it leans by a certain angle α with respect to the longitudinal axis of the vehicle. This placement of the rod 3 allows to obtain the alternating tilting of the two arms 2a, 2b. In other words, when the vehicle leans when turning, with reference to figure 2, the arms 2a, 2b will no longer be aligned on the same horizontal plane, but the arm inside the curve 2b will tend to oscillate upwards with respect to the condition in figure 1 corresponding to the vehicle in a straight motion, while the arm outside the curve 2a will tend to oscillate downwards again with respect to the condition in figure 1. Therefore, the oscillation of the two arms must be of equal but opposite entity. In order to obtain this result, the arms 2a, 2b are connected to the rod 3 by means of the suspensions 4a, 4b which are, in turn, connected to the arms 3a and 3b, respectively, which protrude in a radial direction in two opposite senses, so that rotations of the arms 3a and 3b in opposite directions are associated with the same rotation of the rod.

The arms 3a and 3b are integrally associated with the rod 3, whereby an upward movement of the arm 2b associated with the arm 3b in figure 2 causes a counter clockwise rotation of the arm 3b, and thus of the rod 3 to which the arm 3b is fixed. The opposite arm 3a also rotates counter clockwise and thus lowers the end point of the arm to which the suspension 4a connected to the other arm 2a is hinged, thus causing an oscillation of equal entity but in the opposite direction with respect to the first arm 2b.

The leaning position of the rod 3 with respect to the longitudinal axis of the vehicle by an angle α allows to obtain the condition shown in fig. 1 in which the suspensions 4a and 4b are parallel. Thereby, arms and suspensions are symmetric with respect to the longitudinal axis of the vehicle, and the vehicle is thus perfectly balanced both in the positioning and the structure of the arms and suspensions, which translates into a balanced behaviour of the vehicle right turning and left turning. Tilting system arrest means fixed to the rod 3 may be further included. More in detail, according to the preferred embodiment of the present invention shown in the figures, said tilting arrest means may comprise a disk sector, integrally associated with the rod 3 and thus rotating with the said rod, lockable by means of a calliper 7 fixedly associated to the frame 5 of the vehicle. By actuating the brake calliper 7 which locks the circular segment 6 or a disk, the rotation of the rod 3 about the longitudinal axis thereof is locked, thus locking the tilting of the wheels.

Again, the arms 2a, 2b of the wheels may be advantageously identical, being the right and left arms interchangeable. This further contributes to make the tilting system according to the invention economically advantageous because it is modular. Again, the tilting system according to the present invention allows to obtain the contol of the wheel tilting with a very low number of components, and this also contributes to make the system itself economically advantageous both from the point of view of construction and from the point of view of the reliability and dimensions. We have thus illustrated how the rotating tilting system of the wheels of a vehicle according to the invention achieves the suggested objects.

In particular, we have explained how the rotating tilting system according to the present invention is very small in size and allows to control the tilting of the wheels with a very low number of components, thus forming a system having a highly simple structure which is therefore cost effective to be implemented and maintained. Many changes may be made by a person skilled in the art without departing from the scope of protection of the present invention.

Therefore, the scope of protection of the claims must not be limited to the illustrations or preferred embodiments described by way of example, but rather the claims must include all the features of patentable novelty inferable from the present invention, including all the features which would be treated as equivalent by a person skilled in the art.

Claims

1. A tilting system (1 ) for the wheels of a vehicle with three or four wheels of which at least two wheels are set alongside one another on the same axle, of the type comprising at least one oscillating arm (2a, 2b) for each wheel, said oscillating arms (2a, 2b) being hinged to the frame (5) of said vehicle, and being characterized in that it comprises at least one transmission (3, 3a, 3b, 4a, 4b) designed to connect said arms (2a, 2b) to one another, said transmission comprising at least one connection rod (3) and a mechanism (3a, 3b, 4a, 4b) designed to convert the motion of oscillation of said arms (2a, 2b) into the motion of rotation of said connection rod (3) about its own axis.

2. The tilting system according to the preceding claim, characterized in that said transmission further comprises at least one pair of suspensions (4a, 4b), each of said suspensions (4a, 4b) being hinged at a first end thereof to one of said arms (2a, 2b), and having moreover the second end hinged to the end of a bar (3a, 3b) fixedly associated at its other end to said connection rod (3).

3. The tilting system according to the preceding claim, characterized in that said bars (3a, 3b) extend outwards in the radial direction from said connection rod (3) in opposite directions with respect to one another.

4. The tilting system according to one or more of the preceding claims, characterized in that said connection rod (3) is positioned connected to the frame (5) of said vehicle so as to be able to rotate about its own longitudinal axis and so as to lie in a substantially horizontal plane.

5. The tilting system according to the preceding claim, characterized in that said connection rod (3) is oriented in said horizontal plane so as to form with the longitudinal axis of the vehicle an angle (α).

6. The tilting system according to one or more of the preceding claims, characterized in that it further comprises tilting-arrest means (6, 7).

7. The tilting system (1 ) according to the preceding claim, characterized in that said tilting-arrest means comprise at least one circular segment (6) or a disk fixedly associated to said connection rod (3) and at least one brake calliper (7) fixedly associated to the frame (5) of said vehicle and designed to brake rotation of said circular sector (6) so as to block tilting of the system (1 ).

8. A vehicle comprising a tilting system according to any one of the preceding claims.