WO1998006620A1

WO1998006620A1 - Improvement for vehicle frame

Info

Publication number: WO1998006620A1
Application number: PCT/FR1997/001472
Authority: WO
Inventors: Jean-Philippe Minot
Original assignee: Minot Jean Philippe
Priority date: 1996-08-12
Filing date: 1997-08-08
Publication date: 1998-02-19
Also published as: FR2752213B1; EP0915798A1; JP2001505506A; FR2752213A1; AU3946497A

Abstract

The invention discloses a vehicle with general plane of symmetry, comprising at least one front wheel (7) borne by a front steering assembly comprising guide means (10) and a steering column (9), said vehicle further comprising at least two rear side wheels (4a, 4b) rotatably mounted on self-motivated spin axles (Z, Z') respectively, said rear side wheels (4a, 4b) being borne by a rear carrier assembly articulated on the front steering assembly, said rear carrier assembly comprising a reference plane frame (6) and a rear axle (5) . The invention is characterised in that it comprises rear directing means for moving with respect to the frame (6) reference plane the self-motivated spin axles (Z, Z') of the rear side wheels (4a, 4b), said movement being effected by pivoting in a pivotal plane substantially inclined relative to the horizontal plane.

Description

IMPROVEMENT OF THE VEHICLE CHASSIS OVEN

The object of the present invention is to describe an improvement in the chassis of motor vehicles with more than two wheels in order to provide them with a road behavior comparable to that of two wheels. Said invention advantageously finds its application on motorized vehicles or not having three wheels such as tricycles, sidecars, scooters, for which it will be described.

The type of vehicle mentioned above comprises, on the one hand, a front steering assembly and, on the other hand, a rear carrier assembly comprising a chassis carrying an axle and two wheels. The chassis generally supports the driver's seat and possibly the engine if there is one. It can, moreover, carry a fairing intended to protect the various mechanical parts of the structure or of the engine.

This type of vehicle has some significant drawbacks relating to its handling, and in particular when cornering. Indeed, on the one hand, the position of the center of gravity of the driver vehicle assembly is contained in the general plane of symmetry of the machine at a high height, and on the other hand, the centrifugal forces which apply to the vehicle during a cornering taken quickly cannot be compensated by the displacement of the center of gravity like, for example, on the two wheels which by their inclination allow the compensation of these forces thanks to the lowering of the center of gravity which moves inward of the turn. The combination of these two points explains the instability of such a vehicle as well as its tendency to tip during a tight turn or taken at too high speed. In addition, the rigid structure of the rear carrier assembly as well as the load that it supports causes reduced handling whatever the speed of such a vehicle. This is effectively felt by the difficulty in handling the handlebars during maneuvers carried out at reduced speed. Despite all the efforts made by the manufacturers, vehicles of the motorized tricycles type are not entirely satisfactory because the handling remains poor and the vehicle is not bent around with enough comfort and safety.

The present invention therefore seeks to remedy these drawbacks by simple, effective and reliable means and provides a vehicle whose handling, driving comfort and handling are particularly improved thanks to a rear carrier assembly with variable geometry.

Λ for this purpose the vehicle according to the invention has a general plane of symmetry, it comprises at least one front wheel carried by a front steering assembly comprising guide means and a steering column, said vehicle furthermore comprises at least two wheels rear side mounted in rotation on own axes of rotation and arranged on either side of the general plane of symmetry, said wheels being carried by a rear carrier assembly articulated on the front steering assembly along a guide axis, said assembly rear carrier comprising a chassis carried by a reference plane and a rear axle of transverse axis and is characterized in that it comprises rear orientation means allowing the displacement with respect to the reference plane of the chassis of the own axes of rotation rear side wheels, said movement being pivoted in a pivot plane substantially inclined relative to horizontally.

According to a first embodiment, the own axes of rotation of the rear side wheels coincide with the transverse axis of the rear axle, the rear orientation means being constituted by a central rear articulation allowing the respective movement in pivoting of the rear axle and the chassis about a pivot axis, said pivot axis being orthogonal to the pivot plane and contained in the plane of general symmetry. According to an additional characteristic the pivot axis extends from the bottom and from the front to the top and the rear to form with the horizontal plane an angle σ open towards the rear comprised between 0 and 90 °.

According to an improvement, the vehicle comprises control means intended to manage the respective pivoting movement of the rear axle and of the chassis around the pivot axis.

According to a variant of this improvement, the control means consist of at least one connecting arm articulated at one of its ends on the rear axle and at the other of its ends on a member of the front assembly of steering, said member being integral in rotation with the steering column, said articulated ends of said connecting arm being located on either side of the general plane of symmetry.

According to a second embodiment, the rear orientation means consist of two rear lateral articulations allowing the displacement of the axes of rotation proper to each of the rear lateral wheels relative to the rear axle on which the chassis is fixed, said displacement s '' pivoting around two pivot axes orthogonal to the pivot plane and parallel to the plane of general symmetry so that the proper axes of rotation can form angles βl, β2 respectively open towards l with the chassis reference plane 'front different from 90 °, said pivot axes extending from the bottom and from the front to the top and rear.

In addition, according to an improvement, it comprises control means intended to manage the pivoting movement of the own axes of rotation of the rear side wheels.

These control means may for example be constituted by two link arms articulated between the own axes of rotation of the rear side wheels and a member of the front steering assembly integral in rotation with the steering column. According to another characteristic, the control means make it possible to keep the axes of rotation of the rear side wheels parallel.

According to a complementary characteristic of the invention, the rear carrier assembly comprises a suspension device on each of the rear side wheels.

Other characteristics and advantages of the invention will emerge from the description which follows with reference to the appended drawings which are given only by way of nonlimiting examples.

Figures 1 to 4 illustrate a first embodiment.

Figure 1 is a diagram of the vehicle at rest in side view.

FIG. 2 illustrates the vehicle at rest in perspective.

Figure 3 illustrates the vehicle at rest when viewed from above.

Figure - ". Is a view similar to Figure 3 of the vehicle during a turn.

Figures 5 to 7 illustrate a second embodiment.

FIG. 5 represents the vehicle at rest in perspective.

Figure 6 is a top view of the vehicle at rest.

Figure 7 is a view similar to Figure 6 of the vehicle during a turn.

FIG. H illustrates a variant representing a vehicle with four wheels at rest.

The vehicle at rest will be understood to mean the vehicle in its position according to which it is in a straight path.

The vehicle (1) according to the invention consists of at least one front wheel (7) carried by a front steering assembly (2) articulated on a rear supporting assembly (3) comprising a chassis (6) and an axle rear (5) and carrying at least two rear side wheels (4a, 4b). It has a vertical longitudinal plane of general symmetry (P) when it is at rest.

At first sight, it should be noted that the vehicle may have two front wheels carried by the front steering assembly as in the case of a car for example without departing from the scope of the invention. Furthermore, the invention relates essentially to the rear carrier assembly (3) and more particularly to an improvement concerning the connections between the rear wheels (4a, 4b), the rear axle (5), the chassis (6) and the articulation on the front steering assembly (2). Therefore, for the sake of clarity, the invention will be described and illustrated by means of embodiments representing vehicles with three non-motorized wheels. It goes without saying that an improvement of this type can be used within the framework of a motorized vehicle, without however escaping the claimed field of protection. Thus, the rear carrier assembly comprises a seat (not shown) intended for the driver and carried by the chassis, said chassis possibly being able to carry in a manner known per se in the context of a motorized vehicle the main part of the driving members such as, the tank, the transmission elements, the exhaust and the engine itself.

The vehicle (1) according to the various preferred embodiments of the invention is therefore of the tricycle type and is constituted by a front steering assembly (2) articulated on a rear carrying assembly (3) along an axis (XX ¹ ) contained in the plane (P) which extends from the bottom (BA) and from the front (AV) to the top (HA) and the rear (AR) as illustrated in Figures 1 and 2.

The front steering assembly (2) is, in a manner known per se, constituted in part by a transverse spacing carried by a fork (8) integral in rotation with the steering column (9), the front wheel (7 ) being articulated in rotation on this distance. The steering column (9) can advantageously be articulated directly in rotation along the axis (XX ¹ ) on the rear carrier assembly (3). In addition, the front steering assembly (2) includes guide means (10) such as, for example, a steering wheel or a handlebar intended to control the rotation of the steering column (9) and therefore of the front wheel (7).

The rear carrier assembly (3) generally comprises a rear axle (5) arranged transversely carrying at each of its ends a rear side wheel (4a, 4b) articulated in rotation along its own axis (AA ¹ ), respectively (BB ¹ ). Said axle is carried by a chassis (6) or frame on which is articulated along the axis (XX ¹ ) the front steering assembly (2). Said chassis comprises a reference plane (Q) coincident with the plane (P) when the vehicle is at rest, said plane (Q) possibly being advantageously a plane of symmetry proper to said chassis (6).

According to the invention, the vehicle (1) of the tricycle type comprises rear orientation means (11) allowing the displacement in a plane (I) substantially inclined relative to the horizontal plane (H) of the own axes of rotation (AA ¹ ) and (BB ') of the rear side wheels (4a, 4b) relative to the plane (Q) of the chassis (6) or the displacement in said plane (I) relative to the plane (Q) of the axis of rotation ( ZZ ¹ ) of the rear side wheels if said wheels are mounted in rotation on the same axis (ZZ ¹ ) carried by the rear axle (5), said movements being effected by pivoting.

According to a first embodiment of the vehicle (l) according to the invention, the rear carrier assembly (3) therefore comprises a frame (6) of reference plane (Q) articulated in rotation relative to the front steering assembly (2), said chassis (6) or frame is constituted by a rigid structure of beams disposed between the middle of the rear axle (5) and the articulation between the rear carrier assembly (3) and the front assembly of direction (2), either longitudinally in the plane (Q), or symmetrically with respect to said plane (Q). The rear side wheels (4a, 4b) are articulated in rotation along the same axis (ZZ ') carried by the rear axle (5). The rear orientation means (11) consist of a central rear articulation (12) between the chassis (6) and the rear axle (5). Thus, the rear axle (5) carrying the rear side wheels (4a, 4b) along the axis (ZZ ¹ ) can move relative to the plane (Q) in a plane (I) substantially inclined relative to the horizontal plane (H) from chassis (6), said movement being carried out by pivoting about an axis (YY ¹ ) advantageously contained in the plane (P).

According to this first embodiment, the axis (YY ¹ ) of the central rear articulation (12) around which the respective pivoting movement of the rear axle (5) and of the chassis (6) takes place is orthogonal to the plane (I) and extends from the bottom (BA) and from the front (AV) to the top (HA) and the rear (AR) so as to form in the plane (P) an angle σ with the plane horizontal (H) between 0 ° and 90 ° and advantageously chosen between 45 ° and 90 °. In addition, the axis (YY ¹ ) can advantageously be parallel to the axis (XX ¹ ) in the plane (P). Thus, the rear axle (5) can pivot around the axis (YY ¹ ) relative to the plane (Q) of the chassis (6) so as to be able to form an angle β open towards the front different from 90 °; this pivoting is advantageously carried out between two extreme angular positions of the angle β symmetrical with respect to the reference plane (Q) of the chassis (6).

During a turn, the rotation of the steering column (9) around the axis (XX ¹ ), controlled by the guide means (10) by the driver, causes the respective displacement in pivoting in the plane (I ) of the rear axle (5) and of the chassis (6) around the axis (YY ¹ ) thanks to the central rear articulation (12). Said movement takes place naturally under the effect of the stresses generated by the entry into the curve of the front wheel (7), so that the plane (Q) of the chassis (6) pivots towards the inside of the turn relative to the rear axle (5).

According to this first embodiment, the vehicle further comprises control means (13) intended to manage the respective movement in pivoting around the axis (YY ¹ ) of the rear axle (5) and of the chassis ( 6). Said control means (13) can advantageously manage this movement as a function of the rotation about the axis (XX ¹ ) of the steering column (9) relative to the chassis (6).

The control means are, for example, constituted by a link arm (13) articulated at its two ends, on the one hand, on the rear axle (5) and, on the other hand, on a member of the front steering assembly (2) integral in rotation about the axis (XX ¹ ) of the column steering (9) - Said member can be constituted by the guide means (10) in particular when these are constituted by a handlebar as illustrated in FIGS. 3 and 4. The connecting arm (13) is, moreover, arranged so that its ends (13a, 13b) are articulated on either side of the reference plane (Q) of the chassis; thus, during the rotation of the steering column (9) causing the front wheel (7) to follow the curve of a turn, the link arm (13) manages the respective pivoting between the chassis (6) and the rear axle (5).

According to this embodiment, the rear carrier assembly may advantageously include a suspension or shock absorber device located at each of the rear side wheels (4a, 4b). It goes without saying that the control means (13) could be electronic, hydraulic, pneumatic or electric, without however departing from the claimed protective field of the invention, they could moreover be advantageously adjustable.

According to a second embodiment of the invention, illustrated in FIGS. 5, 6 and 7, the vehicle of the tricycle type consists of a front steering assembly (2) identical to that of the first embodiment on which is articulated around the axis (XX ¹ ) a rear carrier assembly (3) also comprising a frame (6) of reference plane (Q), a rear axle (5) carrying two rear side wheels (4a, 4b). .According to this second mode, the rear orientation means (11) are no longer constituted by a rear central articulation between the chassis (6) and the axle (5) but by two rear lateral articulations (14a, 14b) arranged between the own axes of rotation (AA ¹ ) and (BB ¹ ) of each of the rear side wheels (4a, 4b) and the rear axle (5) of axis (ZZ ¹ ) fixed to the chassis (6). Said lateral articulations (14a, 14b) allow the displacement in a plane (I) substantially inclined relative to the horizontal plane (H) of the axes of own rotation (AA ¹ ) and (BB ¹ ), said displacement being effected by pivoting of so that the two axes (AA ′), (BB ′) can form with the plane (Q) of the chassis (6) angles β1 and β2 open towards the front other than 90 °.

Thus, the rear carrier assembly (3) is therefore constituted by a chassis (6) of the type described above on which is fixed transversely a rear axle (5), said axle carries at each of its ends in an articulated manner the own axes of rotation of the rear wheels (4a, 4b). Each articulation takes place around an axis (Yl Y 'l), respectively (Y2Y'2) orthogonal to the plane (I), said axes being more advantageously parallel to the plane (P) and parallel to each other in a transverse plane orthogonal to the plane (P). These axes extend from the bottom (BA) and from the front (AV) to the top (HA) and the rear (AR) so as to form with the horizontal plane (H) an angle α open towards the rear between 0 ° and 90 ° and advantageously chosen between 45 ° and 90 °.

According to this second embodiment, when the vehicle enters a bend, the rotation of the steering column (9) relative to the chassis (6) about the axis (XX ') causes, through stresses generated, the respective pivoting displacement around the axes (YlY'l) and (Y2Y'2) of the own axes of rotation (AA ') and (BB ¹ ) and the rear axle (5), say the pivoting movement of said axes relative to the reference plane (Q) of the chassis (6).

According to a possible improvement, of this second embodiment, the vehicle comprises control means (13) intended to manage the pivoting movement of the own axes of rotation (.AA ¹ ) and (BB ¹ ) of the rear side wheels (4a , 4b) relative to the axle (5) around the axes (YlY'l) and (Y2Y'2). Said control means (13) can, for example, be constituted by two connecting arms (15a, 15b) articulated at each of their ends, on the one hand, on the axis of rotation proper to a rear side wheel ( 4a, 4b) and, on the other hand, on a member integral in rotation with the steering column (9), said member possibly being, for example, the guide means (10) as illustrated in FIG. 7 or 8. According to this embodiment, the two link arms (15a, 15b) are arranged symmetrically so that the pivoting of the own axes of rotation (AA ¹ ) and (BB ¹ ) takes place simultaneously and so as to maintain the parallelism of said axes, that is to say the parallelism of the two rear wheels (4a, 4b).

In addition, said vehicle (1) can be equipped, as in the first embodiment, with a suspension or shock absorber device on the rear wheels (4a, 4b). It goes without saying that according to what second embodiment the control means (13) could be electronic, pneumatic or electric without departing from the claimed protective field of the invention, they could also be advantageously adjustable.

According to a variant shown in Figure 8, the vehicle according to the invention comprises four wheels, two front wheels (20a, 20b) mounted on a front axle (21) and two rear wheels (4a, 4b) mounted identically to the first mode of realization on the rear axle (5). According to this variant, the axes of rotation of the front wheels, whether merged or not, can move in a plane that is substantially inclined relative to the horizontal, said displacement being carried out in pivoting with respect to the reference plane (Q) of the chassis ( 6). Thus, this pivoting movement of the axes of rotation of the front side wheels can be obtained by means of front orientation means (22) which may be of the same type as the rear orientation means (12) for example.

Of course, the invention is not limited to the embodiments described and represented by way of examples, but it also includes all the technical equivalents as well as their combinations, in particular its adaptation to the front or rear trains of four-wheel vehicles or more.

Claims

1. Vehicle (1), of general plane of symmetry (P), comprising at least one front wheel (7) carried by a front steering assembly (2) comprising guide means (10) and a steering column (9 ), said vehicle further comprising at least two rear side wheels (4a, 4b) mounted for rotation on their own axes of rotation (AA ') respectively (BB') and arranged on either side of the plane (P), said rear side wheels being carried by a rear carrier assembly articulated on the front steering assembly (2) along a guide axis (XX '), said rear carrier assembly comprising a frame (6) of reference plane (Q) and a rear axle (5) with an axis (ZZ ') characterized in that it comprises rear orientation means (11) allowing the displacement with respect to the reference plane (Q) of the chassis (6) of the axes of rotation own (AA '), (BB') of the rear side wheels (4a, 4b), said movement being effected by pivoting in a pivot plane (I) substantially inclined relative to the horizontal plane (H).

2. Vehicle (1) according to claim 1, characterized in that the own axes of rotation (AA ') and (BB ¹ ) of the rear side wheels coincide with the axis (ZZ') of the rear axle (5 ), the rear orientation means (11) being constituted by a central rear articulation (12) allowing the respective pivoting movement of the rear axle (5) and of the chassis (6) around a pivot axis (YY ¹ ), said pivot axis (YY ') being orthogonal to the pivot plane (I) and contained in the plane (P).

3. Vehicle (1) according to claim 2, characterized in that the pivot axis (YY ¹ ) extends from the bottom (BA) and from the front (AV) to the top (HA) and the rear (AR) to form with the horizontal plane (H) an angle σ open towards the rear comprised between 0 and 90 °.

4. Vehicle (1) according to any one of claims 2 and 3, characterized in that it comprises control means (13) intended managing the respective pivoting movement of the rear axle (5) and the chassis (6) around the pivot axis (YY ¹ ).

5. Vehicle (1) according to claim 4, characterized in that the control means (13) consist of at least one link arm (13) articulated at one of its ends (13b) on the rear axle and at the other of its ends (13a) on a member of the front steering assembly (2), said member being integral in rotation with the steering column (9), said articulated ends (13a, 13b) of said arm of connection (13) being located on either side of the general plane of symmetry (P).

6. Vehicle (1) according to claim 1, characterized in that the rear orientation means (11) consist of two rear lateral articulations (14a, 14b) allowing the displacement of the axes of own rotation (AA ') and ( BB ¹ ) of each of the rear side wheels (4a, 4b) relative to the rear axle (5) on which the chassis (6) is fixed, said movement being effected by pivoting around two pivot axes (YlY'l ) respectively (Y2Y'2) orthogonal to the pivot plane (I) and parallel to the plane (P) so that the proper axes of rotation CAA '), (BB ¹ ) can form with the reference plane (Q) of the chassis angles βl, respectively β2 open towards the front different from 90 °, said axes (YlY'l) and (Y2Y'2)) extending from the bottom (BA) and from the front (AV) towards the top (HA) and rear (AR) -

7. Vehicle (1) according to claim 6, characterized in that it comprises control means (13) intended to manage the pivoting movement of the own axes of rotation (AA ¹ ) and (BB ¹ ) of the rear side wheels (4a, 4b).

8. Vehicle (1) according to claim 7, characterized in that the control means (13) consist of two link arms (15a, 15b) articulated between the own axes of rotation of the rear side wheels (AA ¹ ) and (BB ') and a member of the front steering assembly (2) integral in rotation with the steering column (9) -

9. Vehicle (1) according to any one of claims 7 or 8 characterized in that the control means (13) allow to maintain parallel in the plane (I) the own axes of rotation (AA '), (BB ¹ ) of the rear side wheels (4a, 4b).

10. Vehicle (1) according to any one of the preceding claims, characterized in that the rear carrier assembly (3) comprises a suspension device on each of the rear side wheels (4a, 4b).