FR2841870A1 - Suspension system for three-wheeled vehicle that can tilt on bends has force transmission member between transverse connecting bar and dampers - Google Patents

Abstract

The suspension system for a tilting vehicle with a single front wheel and two rear wheels (3) on the ends of rocking arms (10, 11) pivoted on a tubular frame (2) about an axis (25), with a transverse connecting bar (15) and shock absorber (16), incorporates a force transmission member (17) between the transverse bar and shock absorber. The transmission member is in the form of a lever (22) between the transverse bar and shock absorber, able to pivot relative to the tubular frame at one end and to the lower end of the shock absorber at the other, while its centre pivots about the middle of the transverse bar.

Description

The subject of the present invention is an improvement to the suspension.

of a vehicle

reclining on three wheels.

  From patents WO 9843872, FR 2550507 and EP 0606191 AI, a new type of three-wheel tilt vehicle is known, equipped with a front wheel and two rear wheels. Indeed, given the fact that this type of three-wheeled vehicle has a small width, it is necessary that it can tilt when cornering in order to maintain good stability during

of his movements.

  The French patent FR 2680348 also discloses a suspension device suitable for a tilting vehicle with three wheels. This comprises two rear wheels each mounted at the end of a swing arm articulated relative to the chassis. The damping means are interposed between the chassis and the middle of a transverse connecting bar whose ends

  are articulated respectively on the first and second oscillating arms.

  However simple it may be, this architecture nevertheless has some drawbacks.

  For technological reasons relating to the maximum permissible angularity by the components allowing the articulation of the link bar with respect to each of the two arms when the vehicle is tilted, the link bar must be positioned as close as possible to the axis of rotation of the arms. As a result, during pumping movements of the rear axle, the ratio between the displacement of the center of the wheels and the sinking of the damping means is very large. This has the effect of generating significant efforts in the latter and impairing their proper functioning. On the other hand, the solution presented in patent FR 2680348 does not make it possible to have a significant change in the pumping stiffness during vertical movements and in phase of the rear wheels, which could be appreciable for dealing with variations in stresses suffered by the rear axle, especially when transporting a passenger or heavy loads. Finally, the combined respect of the rolling and pumping diagrams imposes an almost vertical positioning of the damping means, which represents a strong constraint for the general design of the vehicle. It could indeed be advantageous, with respect to the integration of the various components of the vehicle, to be able

  benefit from greater freedom of installation of these damping means.

  Also, the present invention aims to overcome these drawbacks and proposes an improvement of this suspension, which limits the forces in the damping means, allows a variation in the stiffness of the suspension in the face of a change in the load at which it is

  subject and allows great freedom of positioning of the damping means.

  To this end, the suspension device for a reclining vehicle with three wheels comprising two rear wheels each mounted at the end of a left swing arm and a right swing arm articulated with respect to the tubular frame around an axis, a bar transverse link whose ends are articulated respectively on the first and second oscillating arms and damping means, is essentially characterized in that it comprises a force transmission element interposed between the transverse connecting bar and the damping means. According to a first embodiment, the force transmission element is a lever which

  cooperates with the damping means and the transverse connecting bar.

  Still according to this first embodiment, one end of the lever is pivotally mounted relative to the tubular frame, the other end of this lever being hingedly connected to one end of the damping means, the other end of said damping means being connected articulated to the tubular frame, this lever being, between its two ends, pivotally mounted substantially in the middle of the transverse connecting bar, According to other embodiments and variants, the force transmission element consists of '' a link and a lever which cooperate with the damping means and the

transverse link bar.

  According to a second embodiment, one end of the link is hinged substantially in the middle of the transverse connecting bar, the other end of this link being hingedly connected to one end of the lever, this lever being between its two ends , pivotally mounted relative to the tubular frame, the other end of this levief being articulated at one end of the damping means, the other end of said means

  shock absorbers being articulated to the tubular frame.

  According to a third embodiment, one end of the link is articulated substantially in the middle of the transverse connecting bar, the other end of this link being mounted articulated between the two ends of the lever, one end of this lever being mounted pivoting relative to the tubular frame, the other end of this lever being articulated at one end of the damping means, the other end of said means

  shock absorbers being articulated to the tubular frame.

  According to a fourth embodiment and its variants as well as a fifth embodiment, one end of the link is pivotally mounted relative to the tubular frame, the other end of this link being hingedly connected to one end of the lever , this lever being, between its two ends, pivotally mounted substantially in the middle of the transverse connecting bar, the other end of this lever being hingedly connected to one end of the damping means, the other end of said means

  shock absorbers being hingedly connected to the tubular frame.

  According to a fifth embodiment, the transverse link bar is located in front

  of the pivot axis of the left and right arms.

  According to the fourth and fifth embodiments, the damping means are in a substantially horizontal position. According to the first embodiment, a point of attachment of the lever on a yoke is

  offset from a pivot axis of the crossbar.

  Other characteristics and advantages of the invention will appear on reading the

  description of embodiments of a suspension for a three-wheel tilting vehicle

  with reference to the accompanying drawings in which: - Figure 1 shows a schematic perspective view of a tilting vehicle with three wheels, - Figure 2 shows a schematic perspective view of a first embodiment of the suspension device according to l invention, - Figure 3 shows a sectional view along a plane parallel to the longitudinal plane of symmetry of the vehicle of the first embodiment of the suspension device according to the invention, - Figure 4 shows a sectional view along a parallel plane in the longitudinal plane of symmetry of the vehicle of the first embodiment of the suspension device according to the invention in the compressed position, - Figure 5 shows a sectional view along a plane parallel to the longitudinal plane of symmetry of the vehicle of a second embodiment embodiment of the suspension device according to the invention, - Figure 6 shows a sectional view along a plane parallel to the plane of symmetry longitudinal line of the vehicle of a third embodiment of the suspension device according to the invention, - Figure 7 shows a sectional view along a plane parallel to the longitudinal plane of symmetry of the vehicle of a fourth embodiment of the suspension device suspension according to the invention, - Figure 8 shows a sectional view along a plane parallel to the longitudinal plane of symmetry of the vehicle of a first variant of the fourth embodiment of the suspension device according to the invention, - Figure 9 shows a sectional view along a plane parallel to the longitudinal plane of symmetry of the vehicle of a second variant of the fourth embodiment of the suspension device according to the invention, - Figure 10 shows a sectional view along a plane parallel to the plane of longitudinal symmetry of the vehicle of a fifth embodiment of the suspension device

according to the invention.

  FIG. 1 represents a tilting vehicle with three wheels which comprises a chassis 4, a front wheel 1 and two rear wheels 3. The chassis 4 comprises, in a known manner, a tubular frame 2 provided with a steering column 5 surmounted by handlebars 6 in the upper part

  and secured to a front fork 7 supporting the front wheel 1 by a hub 8.

  At the rear of this frame, there are two independent oscillating arms, left 10 and right 1 1 arranged on either side of the longitudinal plane of symmetry of the vehicle. This type of swing arm is well known to those skilled in the art, it is generally mounted pivoting about an axis such as 19 or 20. As for the suspension means 9, they are symbolized in phantom

  in this figure 1 and they are the subject of representations detailed in figures 2 to 10.

  In FIG. 2, the two oscillating arms 10 and 11 are shown, as well as the axes of rotation 19 and 20. The oscillating arms 10 and 11 can therefore rotate around the axis 25 which is perpendicular to the direction of advance. and this independently of one another, the suspension device comprises a force transmission element 17 and damping means 16 interposed between the chassis and the swinging arms. The damping means 16 comprise a damping spring combination 24 and the force transmission element 17 comprises a lever 22. In this embodiment, the damping means 16 and the force transmission element 17 cooperate so that the lower end of the spring-shock absorber combination 24 is articulated at the rear end of the lever 22. The front end of the lever 22 is pivotally mounted relative to the tubular frame 2 about an axis 35 perpendicular to the direction of advance. Between its two ends, the lever 22 is articulated at 18 on the yoke 26 secured to a transverse connecting bar 15, located behind the pivot axis 25 of the arms 10 and 11. The yoke 26 is placed substantially in the middle of the connecting bar 15, above this bar as shown in Figure 2 or below as shown in Figure 3. The upper end of the shock absorber spring 24 is articulated relative to the tubular frame 2 of the chassis 4 of way the

  combined spring - shock absorber 24 works substantially along a vertical axis.

  The operating principle of the transverse connecting bar 15 has already been described in patent FR 2680348. It will nevertheless be recalled that its ends are articulated at 30 and 31 respectively relative to the bases 12 and 13 secured to the arms 10 and 11. These articulated ends 30 and 31 include elastic joints and / or any other means capable of simultaneously authorizing rotations and translations on the oscillating arms 10 and 11. This

  arrangement allows the transverse link bar 15 to pivot about an axis 33.

  It goes without saying that other arrangements of the damping means 16 and of the element

  transmission of forces 17 are possible.

  The operation of the suspension device according to the invention is described below, when the vehicle is traveling in a straight line on regular ground, the shock absorbing means, in this case the shock absorbing spring combination 24, take up the forces due to the weight of the vehicle added to the driver's weight. Indeed, the two rear swinging arms 10 and ll go upwards and carry with them the link bar 15 as well as the force transmission element 17 and compress the spring-shock absorber combination 24. The suspension

  is then in a position close to that shown in FIG. 3.

  In this figure, points A, B, C and D represent the intersection between, respectively, the

  axes 33, 18, 35 and 25 and the section plane adopted in this figure.

  The off-center position of the attachment point 18 of the lever 22 on the yoke 26, relative to the axis 33, authorizes the deformation of the quadrilateral ABCD. This provision guarantees the proper functioning of the suspension. The combination of this characteristic with the relative positioning as well as the dimensions of the various components of the suspension makes it possible, in a manner also known, to program the evolution of the stiffness of the suspension and of the forces in the damping means as a function of its depression, Likewise, when the ground becomes irregular or an overload is applied to the vehicle, the oscillating arms 10 and 11 are subjected to variations in movement which are taken up by the combined spring-shock absorber 24 in the same way. This situation is represented on the

figure 4.

  In the case where the vehicle is inclined, the damping means 16 continue to play their role and the elastic joints of the ends 30 and 31 compensate for the variations in length of the connecting bar 15 so that any shocks on each of the wheels can be damped by the spring-shock absorber combination 24. This suspension device therefore allows

  also a dissociation of the damping and tilting capacities of the vehicle.

  The second embodiment of the suspension device shown in FIG. 5 comprises two swing arms identically, a right swing arm 111 and a left swing arm 110 not shown in this sectional view, as well as a connecting bar 11, located behind the pivot axis 125 of these arms. At the end of these oscillating arms are arranged the rear wheels 103. The suspension device comprises a force transmission element 117 and damping means 116 interposed between the chassis and the oscillating arms. The damping means 116 comprise a spring-damper combination 124 and the force transmission element 117 comprises a lever 122 as well as a link 121. In this embodiment, the damping means 116 and the transmission element forces 117 cooperate so that the upper end of the shock absorbing spring combination 124 is articulated at the front end of the lever 122. At its rear end the lever 122 is articulated at the upper end of the link 121. Between its two ends , the lever 122 is pivotally mounted on the tubular frame 2, around an axis 140 perpendicular to the direction of advance. The lower end of the link 121 is articulated relative to the transverse connecting bar 115 at a point located substantially in the middle of this bar. The lower end of the spring-damper combination 124 is articulated on the tubular frame 2. This embodiment allows a positioning of the spring-damper combination 124 in front of the pivot axis 125 of the suspension arms, as well as a positioning of the lever 122 above this same pivot axis 125. According to an identical reasoning to that developed for the previous embodiment, the deformable nature of the AlB lC DI quadrilateral, as well as the relative positioning and the dimensions of the various components of the suspension allow, in known manner, to program the evolution of the stiffness of the suspension and of the forces in the damping means as a function of its depression. This reasoning is

  also applicable to the other embodiments presented below.

  A third embodiment shown in FIG. 6 includes two swing arms identically, a right swing arm 211 and a left swing arm 210 not shown in this sectional view, as well as a link bar 215, located behind the pivot axis 225 of these arms. At the end of these oscillating arms are arranged the rear wheels 203. The suspension device comprises a force transmission element 217 and damping means 216 interposed between the chassis and the oscillating arms. The damping means 216 comprise a spring-damping combination 224 and the force transmission element 217 comprises a lever 222 as well as a link 221. In this embodiment, the damping means 216 and the transmission element efforts 217 cooperate so that the lower end of the spring-shock absorber combination 224 is articulated at the rear end of the lever 222. At its front end, the lever 222 is pivotally mounted relative to the tubular frame 2 along an axis 240 perpendicular to the direction of travel. Between his

  two ends, the lever 222 is articulated at the lower end of the link 221.

  The upper end of the rod 221 is articulated relative to the connecting bar

  transverse 215, at a point located substantially in the middle of this connecting bar.

  The upper end of the spring-shock absorber combination 224 is articulated on the tubular frame 2. This embodiment makes it possible to position the spring-shock absorber combination 224 behind the pivot axis 225 of the suspension arms and the lever 222 in - below

of the link bar 215.

  The fourth embodiment of the suspension device shown in Figure 7 identically comprises two swing arms, a right swing arm 311 and a left swing arm 310 not shown in this sectional view as well as a link bar 315, located behind the pivot axis 325 of these arms. At the end of these oscillating arms are disposed the rear wheels 303. The suspension device comprises a force transmission element 317 and damping means 316 interposed between the chassis and the oscillating arms. The damping means 316 comprise a spring-damping combination 324 and the force transmission element 317 comprises a lever 322 as well as a link 321. In this embodiment, the damping means 316 and the transmission element efforts 317 cooperate in such a way that the lower end of the shock-absorbing spring combination 324 is articulated on the rear end of the lever 322. At its front end, the lever 322 is articulated at the upper end of the link 321. Between its two ends, the lever 322 is articulated on the link bar 315, at a point located substantially in the middle of this link bar. The lower end of the link 321 is pivotally mounted relative to the tubular frame 2, around an axis 340 perpendicular to the direction of advance. The upper end of the spring-shock absorber combination 324 is articulated on the tubular frame 2. This embodiment allows positioning of the shock-absorbing spring combination 324 behind the link bar 315, as well as positioning

  substantially vertical of the link 321 and of the shock absorber spring combination 324.

  A first variant of this embodiment is shown in FIG. 8. In this variant, the suspension device also includes a transmission element

  forces 417 and damping means 416 interposed between the chassis and the swinging arms.

  The shock absorbing means 416 include a spring-shock absorber combination 424 and the force transmission element 417 comprises a V-shaped lever 422 as well as a link 421. In this variant, the shock absorbing means 416 and the transmission element forces 417 cooperate so that the lower end of the shock absorber spring 424 is articulated at the upper end of the lever 422. At its lower end, the lever 422 is articulated at the rear end of the link 421. Between at its two ends, the lever 422 is articulated on the connecting bar 415, at a point situated substantially in the middle of this connecting bar. The front end of the link 421 is pivotally mounted relative to the tubular frame 2, around an axis 440 perpendicular to the direction of advance. The upper end of the spring-shock absorber combination 424 is articulated on the tubular frame 2. This variant allows positioning of the spring-shock absorber combination 424 in front of the connecting rod 415 as well as horizontal positioning.

of the rod 421.

  A second variant of this embodiment is shown in FIG. 9, in which the suspension device likewise comprises a force transmission element 517 and damping means 516 interposed between the chassis and the swinging arms. The damping means 516 comprise a combined spring - damper 524 and the force transmission element 517 comprises a lever 522 as well as a link 521. In this second variant, the damping means 516 and the force transmission element 517 cooperate in such a way that the rear end of the spring-shock absorber combination 524 is articulated at the lower end of the lever 522. At its upper end, the lever 522 is articulated at the rear end of the link 521. Between its two ends, the lever 522 is articulated on the link bar 515, at a point located substantially in the middle of this link bar. The front end of the link 521 is pivotally mounted relative to the tubular frame 2, along an axis 540 perpendicular to the direction of advance. The front end of the spring-shock absorber combination 524 is articulated on the tubular frame 2. This second variant allows substantially horizontal positioning of the spring combination

  shock absorber 524 and link 521.

  A fifth embodiment is shown in FIG. 10 in which the suspension device identically comprises two swinging arms, a right swinging arm 611 and a left swinging arm 610 not shown in this sectional view as well as a connecting bar 615 located this time in front of the pivot axis 625 of these arms. At the end of these oscillating arms are disposed the rear wheels 603. The suspension device likewise comprises a force transmission element 617 and damping means 616 interposed between the chassis and the oscillating arms. The shock-absorbing means 616 comprise a spring-shock-absorbing combination 624 and the force transmission element 617 comprises a lever 622 as well as a link 621. In this embodiment, the shock-absorbing means 616 and the transmission element efforts 617 cooperate so that the front end of the spring-shock absorber combination 624 is articulated at the lower end of the lever 6 2. A

  its upper end, the lever 622 is articulated at the rear end of the link 621.

  Between its two ends, the lever 622 is articulated on the connecting bar 615, at a point located substantially in the middle of this connecting bar. The front end of the link 621 is pivotally mounted relative to the tubular frame 2, around an axis 640 perpendicular to the direction of advance. The rear end of the shock absorber spring 624 is articulated on the tubular frame 2. This arrangement allows a sensiblemient horizontal positioning of the shock absorber spring 624 and the link 621. It also gives greater freedom in the choice of the position of the connecting bar 615. It should be noted that this arrangement of the connecting bar, in front of the pivot axis 625 from

  arm, is applicable to all the other embodiments and variants presented.

  It should also be noted that the embodiments described here are not limiting and that all forms of combinations or arrangements of the links and

levers are possible.

  Although the present invention preferably applies to a vehicle intended for road use, it can also be applied to all types of tiltable vehicles with three wheels or

  more, to machines intended for the leisures as well as toys or models.

  The present invention is also applicable to tilting vehicles with three wheels

fitted with two front wheels.

  Finally, it is obvious that for particular applications, the wheels can advantageously be replaced by other means of connecting the vehicle with the coomime soil,

for example, skis.

Claims (10)

claims   1. Suspension device for a three-wheel tilting vehicle comprising two rear wheels (3, 103, 203, 303, 403, 503, 603) each mounted at the end of a left swing arm (10, 110, 210, 310 , 410, 510, 610) and a straight swinging arm (11. 111, 211, 311, 411, 511, 611) articulated with respect to the tubular frame (2) around an axis (25,, 225, 325 , 425, 525, 625), a transverse link bar (15, 115, 215, 315, 415, 515, 615) the ends of which are articulated respectively on the first and second oscillating arms and damping means (16, 116, 216, 316, 416, 516, 616) characterized in that it comprises a force transmission element (17, 117, 217, 317, 417. 517,   617) interposed between the transverse connecting bar and the damping means.   2. Device according to claim 1, characterized in that the force transmission element (17) is a lever (22) which cooperates with the damping means (16) and the bar transverse link (15).   3. Device according to claims 1 and 2, characterized in that one end of the lever   (22) is pivotally mounted relative to the tubular frame (2), the other end of this lever (22) being hingedly connected to one end of the damping means (16), the other end of said damping means (16 ) being hingedly connected to the tubular frame (2), this lever (22) being, between its two ends, pivotally mounted   substantially in the middle of the transverse connecting bar (15).   4. Device according to claim 1, characterized in that the force transmission element (117, 217, 317, 417, 517, 617) consists of a link (121, 221, 321 421, 521, 621 ) and a lever (122, 222, 322,422, 522, 622) which cooperate with the damping means (116, 216, 316, 416, 516, 616) and the transverse link bar (1 15, 215, 315, 415, 515, 615).   5. Device according to claims 1 and 4, characterized in that one end of the   connecting rod (121) is articulated substantially in the middle of the transverse connecting bar (115), the other end of this connecting rod (121) being hingedly connected to one end of the lever (122), this lever (122) being, between its two ends, pivotally mounted relative to the tubular frame (2), the other end of this lever (122) being articulated at one end of the damping means (116), the other end of said   damping means being articulated to the tubular frame (2).   6. Device according to claims 1 and 4, characterized in that one end of the   rod (221) is articulated substantially in the middle of the transverse connecting bar (215), the other end of this rod (221) being articulated between the two ends of the lever (222), one end of this lever ( 222) being pivotally mounted relative to the tubular frame (2), the other end of this lever (222) being articulated at one end of the damping means (216), the other end of said   damping means being articulated to the tubular frame (2).   7. Device according to claims 1 and 4, characterized in that one end of the   rod (321, 421, 521, 621) is pivotally mounted relative to the tubular frame (2), the other end of this rod (321, 421, 521, 621) being hingedly connected to one end of the lever ( 322, 422, 522, 622), this lever (322, 422, 522, 622) being, between its two ends, pivotally mounted substantially in the middle of the transverse connecting bar (315, 415, 515, 615), l the other end of this lever (322, 422, 522, 622) being hingedly connected to one end of the damping means (316, 416, 51 6, 616), the other end of said damping means being hingedly connected to the bed tubular (2).   8. Device according to claim 1 and any one of the preceding claims,   characterized in that the transverse link bar (15, 115, 215, 315, 415, 515. 615) is located in front of the pivot axis (25, 125, 225, 325, 425, 525, 625) of the arms   left (10, 110, 210, 310, 410, 510, 610) and right (11, 11l1, 211, 311, 411, 511, 611).   9. Device according to claims 1, 4, 7 and 8, characterized in that the means   shock absorbers (516, 616) are in a substantially horizontal position.   10. Device according to claims 1, 2 and 3, characterized in that a point of attachment   (18) of the lever (22) on a yoke (26) is offset relative to a pivot axis (33)   of the cross link bar (15).