Tilting and steerable suspension system with sustained driving, particularly for a three or multi-wheel vehicle

Abstract

The present invention concerns a tilting and steerable suspension system with sustained driving (1) for a vehicle (2) comprising a chassis (23) and three or more wheels of which at least a first wheel (21) and a second wheel (22) are respectively arranged on opposite lateral sides of said vehicle (2). According to the invention, the system (1) comprises at least a first support arm (31, 33) and at least a second support arm (32, 34) adapted, at a respective inner end (35), to be hinged to said chassis (23) and adapted, at a respective outer end, to rotatably support, about a steering axis (S41, S42), respectively a first support element (41) of said first wheel (21) and a second support element (42) of said second wheel (22). The system (1) further comprises at least one pair of second arms (51, 52, 53, 54) hinged, at an outer end, to said first support element (41) and to said second support element (42), respectively, and hinged, at an inner end, to each other, wherein said system (1) comprises a shock absorber (7) hinged at a first end (70) to said chassis (23), said system (1) further comprising a pair of connecting rods (81, 82) hinged, at an inner end, to each other and to a second end (71) of said shock absorber (7) opposite said first end (70). The connecting rods of said pair of connecting rods (81, 82) are hinged, at an outer end, to a portion of said first support arm (31, 33) and to a portion of said second support arm (32, 34), respectively. The system (1) further comprising at least one abutting element (91, 92) configured to respectively abut said first support arm (31, 33) or said second support arm (32, 34) so as to block the possibility of rotation about the respective hinge constraint (C31, C32) present in the respective inner end, beyond a predefined angle of rotation associated with a first banking angle (α) of said vehicle (2).

Description

[0001] TILTING AND STEERABLE SUSPENSION SYSTEM WITH SUSTAINED DRIVING, PARTICULARLY FOR A THREE OR MULTI-WHEEL VEHICLE

[0002] * * *

[0003] FIELD OF THE INVENTION

[0004] The present invention concerns a tilting steerable suspension system with sustained driving, particularly for a three or multi-wheel vehicle. In detail, the present invention refers to motorcycles having at least three wheels, two of which side by side, and which are able to tilt laterally thanks to the presence of a connection system between the two side-by-side wheels.

[0005] BACKGROUND

[0006] Vehicles of the type to which reference is made are vehicles with three or more wheels, such as motorcycles and scooters, two of which, the front ones according to the best known embodiments, are aligned on an axis and swinging by means of a mechanical or oleodynamic pendulation system. These vehicles have a steerable suspension system that connects pairs of wheels allowing the vehicle itself to tilt with respect to the ground. In fact, the prerogative of the three- or multi-wheel motorcycles to which reference is made is to be able to tilt laterally by a certain angle towards the inside of a curve, while travelling the same, exactly as happens with a two-wheel vehicle, such as a conventional type motorcycle.

[0007] This functionality is provided by a tilting or pendulation mechanism usually composed of a system of levers that connect the hubs of the paired wheels on the same axis, which allows the wheels on one side to move upwards with respect to the vehicle and the wheels on the opposite side to move correspondingly downwards, again with respect to the vehicle.

[0008] These mechanisms also include one or more shock absorbers, composed of springs and dampers, to absorb the irregularities of the ground and control the longitudinal load transfers of the entire vehicle.

[0009] In the current state of the art, the connection system between two side-by-side wheels is of a mechanical type, with longitudinal or transverse arms, with various schemes already known in the automotive or motorcycle design sector. In particular, a first mechanism guides the vertical movement of the two wheels, a second mechanism couples the right wheel to the left wheel so that the downward movement of one wheel corresponds to an equal upward movement of the opposite wheel, a third mechanism connects both wheels to the shock absorber, a fourth mechanism (in the case of front wheels) allows the steering to guide the vehicle.

[0010] However, these known pendulation systems are not free of drawbacks or limitations, among which it should be included that they do not allow to have a progressive and sustained movement of descent in the curve, i.e. change of tilt of the vehicle, which therefore provides much more safety to the rider than riding a simple two-wheel motorcycle.

[0011] Another drawback of these pendulation systems of known type derives from the excess weight compared to that of a two-wheel motorcycle or scooter with the same characteristics, which is highlighted above all in manoeuvres from a standstill when the rider must keep the vehicle in a straight position or when he must return it to a straight position after a manoeuvre in which the vertical ity of the vehicle has been lost.

[0012] A further drawback of such pendulation systems of known type consists in the fact that they are often not easily adaptable according to the needs of the rider, either expert or beginner.

[0013] It is therefore evident that the rider who must move this type of vehicle from a standstill, tilting it to the right or to the left with respect to the vertical, must put much more effort the heavier the three or multi-wheel vehicle is compared to a traditional vehicle.

[0014] SUMMARY OF THE INVENTION

[0015] In light of the above, the task of the present invention is to realise a tilting steerable suspension system particularly for a three or multi-wheel vehicle that overcomes the limits of the prior art allowing to sustain and make the driving and the descent in the curve of the vehicle more natural and safer.

[0016] Within the scope of this task, an object of the present invention is to realise a tilting steerable suspension system that allows the rider to more easily bring the vehicle into an upright position when the same is in a tilted position, both from a standstill and when in movement while travelling along a curve, for example.

[0017] Another object of the present invention is to obtain a vehicle that is safer and easier to drive and manage, both from a standstill and when in movement, due to the fact that it has a tilting steerable suspension system that allows limiting the force necessary to return the vehicle to an upright position, starting from a tilted position.

[0018] A further object of the invention consists in realising a tilting steerable suspension system that is able to give the broadest guarantees of reliability and safety in use. Another object of the invention consists in realising a tilting steerable suspension system that can adapt to both the riding style of an experienced rider and the riding style of a beginner rider, thanks to the possibility of modifying the value of sustenance of the vehicle.

[0019] Yet another object of the invention consists in realising a tilting steerable suspension system that is easy to realise and economically competitive if compared to the prior art.

[0020] The above task, as well as the purposes mentioned and others that will better appear below, are achieved by a tilting and steerable suspension system with sustained driving according to claim 1 , as well as by a three- or multi-wheel vehicle according to claim 7.

[0021] Other features are provided in the dependent claims.

[0022] LIST OF FIGURES

[0023] Further characteristics and advantages of the present invention will become more apparent from the exemplary but non-limiting description of a preferred embodiment of the present invention illustrated with the aid of the attached drawings in which:

[0024] - figure 1 is a perspective view of the front part of a three-wheel vehicle comprising a tilting and steerable suspension system with sustained driving, according to the invention;

[0025] - figure 2 is another perspective view of the part of vehicle illustrated in figure 1 , but with the two front wheels partially removed;

[0026] - figure 3 is a perspective view from below of the tilting and steerable suspension system with sustained driving, according to the invention;

[0027] - figure 4 is another perspective view from below of the tilting and steerable suspension system with sustained driving, according to the invention;

[0028] - figure 5 is a front view of the tilting and steerable suspension system with sustained driving, according to the invention, in an upright position;

[0029] - figures 6, 6a and 6b are front views of the tilting and steerable suspension system with sustained driving, according to the invention, tilted according to a first banking angle, illustrated respectively without wheels, with wheels and without wheels or chassis;

[0030] - figures 7 and 7a are front views of the tilting and steerable suspension system with sustained driving, according to the invention, tilted according to a second banking angle, illustrated respectively with wheels and without wheels;

[0031] - figures 8 and 8a are front views of the tilting and steerable suspension system with sustained driving, according to the invention, tilted according to an angle of maximum banking, illustrated respectively with wheels and without wheels;

[0032] - figure 9 is a perspective view of a part of the tilting and steerable suspension system with sustained driving, according to the invention;

[0033] - figures 10 and 10a are front views of the part of the suspension system illustrated in figure 9, in two different variants.

[0034] DETAILED DESCRIPTION OF THE INVENTION

[0035] With particular reference to the figures, the tilting and steerable suspension system with sustained driving is indicated globally with reference numeral 1 . Such a system 1 is suitable for use for a vehicle 2 comprising a chassis 23 and three or more wheels of which at least a first wheel 21 and a second wheel 22 are respectively arranged on opposite sides of the vehicle 2 itself.

[0036] The vehicle 2 can be, for example, a pendulating three-wheel vehicle, with an endothermic engine, as well as with an electric motorisation. Alternatively, the vehicle 2 can also be a four-wheel vehicle, always of the pendulating type.

[0037] The two wheels 21 and 22 placed on the sides of the vehicle 2 can also be offset from each other.

[0038] According to the embodiment illustrated in the accompanying figures, the vehicle 2 is a three-wheel vehicle, wherein the steerable and swinging wheels are the two front wheels 21 and 22, which are coupled on the same axle (front axle).

[0039] According to the invention, the tilting and steerable suspension system comprises at least a first support arm 31 , 33 and at least a second support arm 32, 34 adapted, at a respective inner end (generally indicated with 35), to be hinged to the chassis 23 and adapted, at a respective outer end, to rotatably support, about a steering axis S41 , S42, respectively a first support element 41 of the first wheel 21 and a second support element 42 of the second wheel 22.

[0040] The terms “inner” and “outer” are to be understood as referred to the vehicle 2: “inner” indicates a direction towards the centre of the vehicle 2, “outer” indicates a direction towards the sides of the vehicle 2.

[0041] The system 1 comprises at least one pair of tie-rods 51 , 52, 53, 54 hinged, at an outer end (generally indicated with 55 and 56) to the first support element 41 and to the second support element 42, respectively.

[0042] The aforesaid tie-rods 51 , 52, 53, 54 are also hinged, at an inner end 57, to each other. The system 1 further comprises a shock absorber 7 hinged, at a first end 70 to the chassis 23.

[0043] The system 1 also comprises a pair of connecting rods 81 , 82, hinged, at an inner end, relative to each other and at a second end 71 of the shock absorber 7 opposite to the aforesaid first end 70. The connecting rods 81 , 82 of said pair of connecting rods are then hinged, at an outer end, to a portion of the first support arm 31 , 33 and to a portion of the second support arm 32, 34, respectively.

[0044] The system 1 further comprises at least one abutting element 91 , 92 configured to respectively abut the first support arm 31 , 33 or the second support arm 32, 34 so as to block the possibility of rotation about the respective hinge constraint C31 , C32 present in the respective inner end 35, beyond a predefined angle of rotation associated with a first banking angle of the vehicle 2.

[0045] In essence, as evident by comparing in particular figures 5 and 6, as the vehicle 2 banks with respect to a vertical direction, the first support arm 31 , 33 and the second support arm 32, 34 are free to rotate about the respective hinge constraint C31 , C32 until the vehicle 2 reaches a first banking angle a at which the first support arm 31 , 33 or the second support arm 32, 34 (depending on the banking side) abut the abutting element 91 , 92.

[0046] In fact, as better explained below, within this first banking angle a the vehicle 2 does not need verticalising effects in the movements from a standstill and in the dynamic driving because it is a small or medium banking angle. Thus, from a standstill, the rider with small or medium efforts is able to return the vehicle 2 to an upright position and in the dynamic driving it is not particularly useful to have this type of verticalising effect. Preferably, as illustrated in the accompanying figures, there are two pairs of support arms 31 , 32 and 33, 34 arranged parallel to each other.

[0047] Preferably, as illustrated in the accompanying figures, the system 1 comprises a first bracket 45 and a second bracket 46 hinged to the first support element 41 and to the second support element 42, respectively. The tie-rods 51 , 52, 53, 54 are hinged, at their outer end 55 and 56, to the first bracket 45 and the second bracket 46, respectively.

[0048] Preferably, the system 1 comprises two pairs of tie-rods 51 , 52 and 53, 54, parallel two by two, hinged at the respective outer ends 55, 56 to the support elements 41 , 42 of the two wheels 21 , 22, for example by means of a same bracket 45, 46.

[0049] Preferably, the tie-rods 51 , 52, 53, 54 are hinged to each other, at the respective inner end 57 by means of a common hinge element C58, and / or by means of a common hinge element C58 obtained in a swinging support 59 associated with the chassis 23. Preferably, the connecting rods 81 , 82 are hinged, at the inner end thereof, to each other and to the second end 71 of the shock absorber 7 by means of a common hinge element C83.

[0050] Preferably, the shock absorber 7 is configured to compress only when the vehicle 2 banks at a banking angle greater than the first banking angle (a) at which said predefined rotation angle is associated.

[0051] Preferably, the system 1 comprises a pair of elastomeric end-stop elements 110, 111 designed to feedback respective abutting elements of the system 1 (which may be constituted, for example, by two of the tie-rods 51 , 52, 53, 54) when the vehicle 2 banks at an angle [3 of maximum banking, greater than the first banking angle a.

[0052] In figures 6, 6a, 6b the system 1 is illustrated in a banking configuration at a first banking angle a.

[0053] In figures 8, 8a the system 1 is illustrated in a banking configuration at an angle of maximum banking [3.

[0054] In figures 7, 7a the system 1 is illustrated in a banking configuration at a second angle, comprised between the first banking angle a and the angle of maximum banking [3. When the vehicle 2 is at a banking angle between the upright position and the first banking angle a, the first support arm 31 , 33 and the second support arm 32, 34 are free to rotate until one of the two rests on the abutting element 91 , 92. Within this first banking angle a, the vehicle 2 is statically and dynamically comparable to a normal two-wheel motorcycle or scooter, with the advantage derived from the fact of having an extra wheel in the front part that guarantees safe braking and travelling of the curves.

[0055] When the vehicle 2 is at the angle of maximum banking (3, at least one element of the system 1 , such as one of the tie-rods 51 , 52, 53, 54 rests, for example with its own outer end 56, 57, on one of the two elastomeric end-stop elements 110, 111.

[0056] The verticalization effect of the present invention is implemented between the first banking angle a and the angle of maximum banking [3. The explanation for this effect lies in the fact that in order to bring the vehicle 2 from the banking angle a to the banking angle (3, the shock absorber 7 must compress by effect of the kinematics by a portion, thus storing an energy that is released in the steps of reduction of the banking angle, that is when the vehicle is brought from the angle [3 (or in any case from an angle greater than the first banking angle a) to the angle a.

[0057] Preferably, the at least one abutting element 91 , 92 comprises a pair of abutting elements, the first support arm 31 , 33 or the second support arm 32, 34 being capable of abutting against the outer surface 910, 920 of said abutting elements. In particular, as illustrated in the accompanying figures, a first abutting element 91 acts as an abutment for the first support arm 31 , 33, while a second abutting element 92 acts as an abutment for the second support arm 32, 34.

[0058] Preferably, in the case where the system 1 has a pair of support arms 31 , 32 and 33, 34 there may be two pairs of abutting elements, one for each support arm. Advantageously, the support arm indicated with 31 , 33 is in one piece as well as the support arm 32, 34.

[0059] Preferably, the abutting elements 91 , 92 may comprise rubber pads.

[0060] Preferably, the aforesaid pair of abutting elements 91 , 92 is selectable within a set comprising at least two pairs of abutting elements, wherein the abutting elements of a first pair have an overall footprint different from the overall footprint of the abutting elements of a second pair of abutting elements.

[0061] By selecting a different pair of abutting elements having different overall footprint it is de facto possible to increase or decrease the angle of rotation allowed to the first support arm 31 , 33 or the second support arm 32, 34 before striking against one of the two abutting elements and it is therefore possible to select different values for the first banking angle a beyond which the intervention of the shock absorber 7 takes over. Preferably the pair of abutting elements 91 , 92 is made of an elastomeric material and is selectable within a set comprising at least two pairs of abutting elements, wherein the elastomeric material of the abutting elements of a first pair has an elastic coefficient different from the elastic coefficient of the material of the abutting elements of a second pair of abutting elements.

[0062] Preferably, said abutting elements 91 , 92 are cylindrical bodies, so that a pair of cylinders 91 , 92 is selectable within a set comprising at least two pairs of cylindrical bodies, wherein the cylindrical bodies of a first pair have a base diameter of a length different from the length of the base diameter of the cylindrical bodies of a second pair of cylindrical bodies.

[0063] By selecting a different pair of cylindrical bodies with different diameters it is de facto possible to increase or decrease the angle of rotation allowed to the first support arm 31 , 33 or the second support arm 32, 34 before striking one of the two cylindrical bodies and it is therefore possible to select different values for the first banking angle a beyond which the intervention of the shock absorber 7 takes over.

[0064] Preferably, the pair of cylindrical bodies 91 , 92 is made of an elastomeric material and is selectable within a set comprising at least two pairs of cylindrical bodies, wherein the elastomeric material of the cylindrical bodies of a first pair has an elastic coefficient different from the elastic coefficient of the material of the cylindrical bodies of a second pair of cylindrical bodies.

[0065] In this way it is also possible to vary the response of the vehicle 2 at the time of reaching the first banking angle a beyond which the intervention of the shock absorber 7 takes over.

[0066] Said cylindrical bodies of elastic material can be positioned differently in the areas of abutment with the arms 31 , 33, and 32, 34, for example in the front rather than in the rear part as indicated in the figures.

[0067] The support arms 31 , 32 and 33, 34 and the tie-rods 51 , 52 and 53, 54 define an articulated parallelogram that defines the so-called “parallelogram of the suspension”. The support elements 41 , 42 of the wheels 21 , 22 comprise, in a manner known per se, the hubs of the wheels 21 , 22 and the disc brakes of the braking system.

[0068] The drawings also depict the steering column 120 and the steering tie rods 121 , 122 of the system 1 . In the upper part the steering column 120 engages the handlebar 123 of the vehicle 2.

[0069] Preferably, as illustrated in particular in figures 9, 10, 10a, the connecting rods 81 , 82 are hinged, at the points indicated with C81 and C82, to a central portion of the first support arm 31 , 33 and of the second support arm 32, 34, respectively.

[0070] Preferably, the connecting rods 81 , 82 have a circumferential arc shape that passes through the hinge centres C81 , C82 with the support arms 31 , 33 and 32, 34 and with the hinge centre C83 to which both the inner ends of the connecting rods 81 , 82 themselves and the second end 71 of the shock absorber 7 are hinged. The present invention also concerns a vehicle 2 comprising a chassis 23 and three or more wheels of which at least a first wheel 21 and a second wheel 22 are respectively arranged on opposite lateral sides of said vehicle 2, further comprising a tilting and steerable suspension system with sustained driving 1 as described above.

[0071] In practice, it has been found that the tilting and steerable suspension system with sustained driving, particularly for a three or multi-wheel vehicle, according to the present invention, fulfils the task as well as the intended purposes in that it allows the rider to more easily bring the vehicle to an upright position when the same is in a tilted position, both from a standstill and when in movement while travelling along a curve, for example, by reducing in particular the force necessary to return the vehicle to an upright position, as a function of the banking angle reached.

[0072] Another advantage of the system, according to the invention, consists in the fact that the ease to return the vehicle to an upright position occurs only upon reaching a predefined banking angle. In fact, at reduced banking angles, the shock absorber is not stressed.

[0073] A further advantage of the system, according to the invention, consists in the fact that different driving configurations can be easily set, being able to substantially choose the banking angle beyond which the verticalizing effect of the present invention occurs.

[0074] The tilting and steerable suspension system with sustained driving thus conceived is susceptible to numerous modifications and variants all falling within the scope of the inventive concept.

[0075] Furthermore, all the details can be replaced by other technically equivalent elements. In practice, any materials can be used according to requirements, as long as they are compatible with the specific use, the dimensions and the contingent shapes.

Claims

CLAIMS1 . A tilting and steerable suspension system with sustained driving (1 ) for a vehicle (2) comprising a chassis (23) and three or more wheels of which at least a first wheel (21 ) and a second wheel (22) are respectively arranged on opposite lateral sides of said vehicle (2), said system (1 ) comprising at least a first support arm (31 , 33) and at least a second support arm (32, 34) adapted, at a respective inner end (35), to be hinged to said chassis (23) and adapted, at a respective outer end, to rotatably support, about a steering axle (S41 , S42), respectively a first support element (41 ) of said first wheel (21 ) and a second support element (42) of said second wheel (22), said system (1 ) comprising at least a pair of tierods (51 ,53,52,54) hinged, at an outer end (55, 56), to said first support element (41 ) and to said second support element (42), respectively, and hinged, at an inner end (57), to each other, wherein said system (1 ) comprises a shock absorber (7) hinged at a first end (70) to said chassis (23), said system (1 ) further comprising a pair of connecting rods (81 , 82) hinged, at an inner end, relative to each other and at a second end (71 ) of said shock absorber (7) opposite to said first end (70), said pair of connecting rods (81 , 82) being hinged, at an outer end, to a portion of said first support arm (31 , 33) and to a portion of said second support arm (32, 34), respectively, said system (1 ) further comprising at least one abutting element (91 , 92) configured to respectively abut said first support arm (31 , 33) or said second support arm (32, 34) so as to block the possibility of rotation about the respective hinge constraint (C31 , C32) present in the respective inner end, beyond a predefined angle of rotation associated with a first banking angle (a) of said vehicle (2).

2. System (1 ), according to the preceding claim, in which said shock absorber (7) is configured to compress by a portion only when said vehicle (2) banks at an angle greater than said first banking angle (a) at which it is associated with said predefined angle of rotation.

3. System (1 ), according to claim 1 or 2, comprising a pair of elastomeric end-stop elements (110, 111 ) designed to feedback respective abutting elements (51 , 52, 53, 54) of said system (1 ) when said vehicle (2) banks at an angle ([3) of maximum banking greater than said first banking angle (a).

4. System (1 ), according to claim 1 or 2, wherein said at least one abutting element(91 , 92) comprises a pair of abutting elements, the first support arm (31 , 33) or the second support arm (32, 34) being capable of abutting against the outer surface (910, 920) of said abutting elements.

5. System (1 ), according to claim 4, wherein said pair of abutting elements (91 , 92) is selectable within a set comprising at least two pairs of abutting elements, wherein the abutting elements of a first pair have an overall footprint different from the overall footprint of the abutting elements of a second pair of abutting elements, so as to increase or decrease the angle of rotation allowed to the first support arm (31 , 33) and / or the second support arm (32, 34) before striking against one of the two abutting elements.

6. System (1 ), according to claim 4 or 5, wherein the pair of abutting elements (91 , 92) is made of an elastomeric material and is selectable within a set comprising at least two pairs of abutting elements, wherein the elastomeric material of the abutting elements of a first pair has an elastic coefficient different from the elastic coefficient of the material of the abutting elements of a second pair of abutting elements.

7. System (1 ), according to one or more of the preceding claims, wherein said at least one abutting element (91 , 92) comprises a pair of cylindrical bodies, wherein said first support arm (31 , 33) or said second support arm (32, 34) are suitable for abutting against the lateral cylindrical surface (910, 920) of said cylindrical bodies.

8. System (1 ), according to claim 7, wherein said pair of cylindrical bodies is selectable within a set comprising at least two pairs of cylindrical bodies, wherein the cylindrical bodies of a first pair have a base diameter of a length different from the length of the base diameter of the cylindrical bodies of a second pair of cylindrical bodies.

9. System (1 ), according to claim 7 or 8, wherein said pair of cylindrical bodies is made of an elastomeric material and is selectable within a set comprising at least two pairs of cylindrical bodies, wherein the elastomeric material of the cylindrical bodies of a first pair has an elastic coefficient different from the elastic coefficient of the material of the cylindrical bodies of a second pair of cylindrical bodies.

10. A vehicle (2) comprising a chassis (23) and three or more wheels of which at least one first wheel (21 ) and a second wheel (22) are respectively arranged onopposite lateral sides of said vehicle (2), characterised by comprising a tilting and steerable suspension system with sustained driving (1 ) according to one or more of the preceding claims.

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