Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
  • B62K—CYCLES; CYCLE FRAMES; CYCLE STEERING DEVICES; RIDER-OPERATED TERMINAL CONTROLS SPECIALLY ADAPTED FOR CYCLES; CYCLE AXLE SUSPENSIONS; CYCLE SIDE-CARS, FORECARS, OR THE LIKE
  • B62K25/00—Axle suspensions
  • B62K25/04—Axle suspensions for mounting axles resiliently on cycle frame or fork
  • B62K25/28—Axle suspensions for mounting axles resiliently on cycle frame or fork with pivoted chain-stay
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60G—VEHICLE SUSPENSION ARRANGEMENTS
  • B60G11/00—Resilient suspensions characterised by arrangement, location or kind of springs
  • B60G11/02—Resilient suspensions characterised by arrangement, location or kind of springs having leaf springs only
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
  • B62K—CYCLES; CYCLE FRAMES; CYCLE STEERING DEVICES; RIDER-OPERATED TERMINAL CONTROLS SPECIALLY ADAPTED FOR CYCLES; CYCLE AXLE SUSPENSIONS; CYCLE SIDE-CARS, FORECARS, OR THE LIKE
  • B62K25/00—Axle suspensions
  • B62K25/04—Axle suspensions for mounting axles resiliently on cycle frame or fork
  • B62K25/12—Axle suspensions for mounting axles resiliently on cycle frame or fork with rocking arm pivoted on each fork leg
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
  • F16F1/00—Springs
  • F16F1/02—Springs made of steel or other material having low internal friction; Wound, torsion, leaf, cup, ring or the like springs, the material of the spring not being relevant
  • F16F1/18—Leaf springs
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60G—VEHICLE SUSPENSION ARRANGEMENTS
  • B60G2202/00—Indexing codes relating to the type of spring, damper or actuator
  • B60G2202/10—Type of spring
  • B60G2202/11—Leaf spring
  • B60G2202/116—Leaf spring having a "C" form loaded only at its ends transversally to its central axis
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
  • B62K—CYCLES; CYCLE FRAMES; CYCLE STEERING DEVICES; RIDER-OPERATED TERMINAL CONTROLS SPECIALLY ADAPTED FOR CYCLES; CYCLE AXLE SUSPENSIONS; CYCLE SIDE-CARS, FORECARS, OR THE LIKE
  • B62K2201/00—Springs used in cycle frames or parts thereof
  • B62K2201/06—Leaf springs

Definitions

• Cycle type vehicle suspension provided with an elastic element making it possible to obtain an optimum static compression curve, elastic element optimized for such a suspension
• the technical field of the invention is that of vehicle suspensions, in particular that of cycle suspensions such as those intended to be placed in mounting of the steering wheel of the cycle, and / or in mounting of the rear wheel of the cycle.
• the suspension of vehicles is intended to overcome the irregularities of the surface on which the vehicle moves by reducing the impact on the vehicle, avoiding mechanical fatigue, excessive wear, maintaining contact between the wheels and the ground despite its irregularities and improving driving comfort.
• a suspension is necessarily composed of a system of energy dissipation ensuring shock absorption, typically provided by hydraulic rolling or mechanical friction, and an elastic system opposing the movement of the wheel and ensuring its return at the equilibrium point.
• the elastic system must be able to weakly oppose the movement of the wheel around its equilibrium position in order to guarantee a high sensitivity on small impacts (filtration of the vibrations) but also to be able to strongly oppose larger shocks to avoid the phenomenon of tailgating, that is to say the arrival in abutment of the suspension which no longer plays its role.
• the visualization of the force (in N) of the elastic system in opposition to the displacement of the wheel in the absence of dissipation of energy (ie without considering the energy dissipation system) is called static compression curve (or traction in the case of a "pulled" elastic system). This is called static behavior of the suspension.
• an optimal static compression curve should have more or less linear, progressive or regressive portions to provide the desired behavior over the range of travel of the available wheel called deflection.
• the elastic systems conventionally used are springs biased in bending (helical spring or bending blade) or pneumatic springs stressed in compression.
• the former exhibit a quasi-linear static behavior that creates bottlenecks.
• the second ones exhibit an exponential static behavior which does not make it possible to optimize the whole of the available deflection.
• mechanical elements typically a rod / rocker assembly
• the addition of these parts generates an increase in the weight of the suspension, a larger number of parts and a greater complexity which affects the reliability of the assembly and makes it difficult to integrate.
• the document FR3004415 provides a deformable quadrilateral suspension, with an independent damper connected to a force return part called rocker, which itself is connected to the fork via a link-type connecting piece.
• This assembly with these different additional connecting pieces makes it possible to improve the progressivity of the compression curve of the shock absorber in order to tend towards an optimal compression curve.
• the elastic elements conventionally used, and not allowing to obtain an optimum compression / traction curve, are:
• the pneumatic springs whose element ensuring the elastic function (air) is still used in compression, have the particularity of generating an exponential compression curve and which by nature are very insensitive at the beginning of the race because of the pneumatic pressure exerted on the joints.
• these elements have a large number of parts, some in motion (friction), require frequent maintenance and have failures of reliability (leakage, friction, play, wear), - Elastomers, foams and other soft materials that must be integrated into a mechanical assembly, allow a very limited travel, and define a non-optimal compression curve.
• the present invention aims to provide a suspension system without the disadvantages of the prior art and to define a compression curve approximating an ideal or optimal curve, without involving problems of overweight, reliability, longevity or d congestion.
• the invention aims to solve this problem by proposing a suspension system of a wheel of a vehicle comprising:
• an elastic blade comprising two mechanical connection means respectively to the two parts in relative mobility and having a bending elasticity at least ten times greater than the elasticity in tension and being elastically deformable between:
• the suspension system being deformable between:
• the suspension according to the invention solicits the resilient means (the flexible blade) in a different way from the manner in which it is stressed in conventional suspensions in order to create a progressive transfer of low flexural stress to a tensile stress of strong rigidity.
• the deformation of this elastic means of course remains an elastic deformation but the rigidity of this elastic means evolves as a function of the intensity of the stress and the behavior curve is not linear, even in the absence of elements. additional reported.
• the elastic element of the suspension according to the invention is chosen so that it does not undergo only bending stresses over the entire range of stresses, but an evolution of these stresses when the stresses increase, since bending stresses for low intensity stresses, tensile stresses for high intensity stresses and thus a nonlinear stiffness response. This mechanism works perfectly in the case of an initially curved blade that is just stretched / pulled.
• the device according to the invention may furthermore have one and / or the other of the following characteristics:
• the state of compression of the system comprises a state of maximum compression in which the parts in relative mobility are in a configuration spaced apart as far as possible from one another and urge the blade by its connecting means to its extension state maximum.
• - Said connecting means each have at least one degree of freedom in rotation along an axis normal to the median plane of said blade.
• the blade is made of a composite material comprising fibers forming a closed loop surrounding inserts forming the connecting means to the parts in relative mobility
• the profile of said blade has at least two opposite bending directions.
• the profile of said blade has a single direction of bending.
• the profile of said blade has a non-constant radius of curvature.
• the profile of said blade has a non-constant thickness.
• the blade has at least one zone extending cumulatively over less than 10% of the length and having a stiffness at least 10% greater than the average stiffness in the other zones.
• - Said blade has a profile defined by the combination of a main profile having at least one radius of curvature RI and a secondary profile of radius of curvature R2 less than half the radius of curvature RI. said blade is symmetrical with respect to the median plane.
• said moving parts are provided on a deformable quadrilateral.
• said moving parts are provided on a deformable quadrilateral comprising four pivots, the connecting means of the two-part blade with relative mobility of the suspension comprising at least one pivot of the quadrilateral and / or at least one pivot mounted on one segments of the quadrilateral or on an extension of one of the segments of the quadrilateral.
• said moving parts are provided on a triangle of a cycle frame and an oscillating arm connected by a pivot to this triangle, and to the axis of rotation of a wheel of the cycle, the connecting means of the two-piece blade in relative mobility of the suspension comprising at least one additional pivot C, coinciding with one of the vertices of the triangle or attached to one of the segments of the triangle and / or at least one pivot mounted on the oscillating arm or an extension of the arm oscillating.
• the ends of the blade are mechanically connected respectively to two parts in relative mobility of a damping device.
• the invention also relates to the blade of the suspension system above.
• FIG. 1 represents a diagram illustrating the compression / traction curves obtained for a helical spring or a bent plate (curve marked by solid squares), a pneumatic spring (curve marked by circles) and an embodiment of FIG. a blade drawn according to the invention (curve marked by crosses) schematically,
• FIG. 2 which represents the drawn composite blade used within the suspension according to the invention, according to a first embodiment in which this blade comprises two different radii of curvature, and illustrating the connecting means of this blade to the suspension parts deviating from each other during the compression of the suspension, constituted in the illustrated example of metal inserts,
• FIG. 3 which illustrates in a perspective view the edge of the blade according to the invention, showing a variation in the thickness of the blade, according to a second possible embodiment
• FIGS. 4 to 9 illustrate, by different views, a blade according to a third embodiment of the invention:
• FIG. 6 a sectional view of the blade along the median plane
• FIG. 7 o a view from above of the blade in its state of rest (FIG. 7)
• FIG. 8 a three-quarter perspective view from above of the composite blade in an intermediate extension state
• FIG. 9 a three-quarter perspective view from above of the composite blade in its state of maximum extension in which the inter-axis has the same length as the length of the neutral fiber of the blade (FIG. 9)
• FIG. 10 illustrates a schematic representation of the composite blade according to the invention used in the following figures
• FIGS. 11A, 11B, 11C; 12A, 12B; 13A, 13B; 14A, 14B; 15A, 15B show schematically the integration of the composite blade according to the invention according to five possible configurations within a suspension before a cycle (FIGS. 11A, 11B, 11C; 12A, 12B) and within a rear suspension of a cycle (Figs. 13A, 13B; 14A, 14B; 15A, 15B)
• Figures 16A and 16B show schematically the association of the flexible blade of the suspension according to the invention to a damper.
• the invention as shown in Figure 11B relates to a vehicle suspension (a cycle in the illustrated examples) provided with a deformable blade biased stretching between two points of the suspension apart from each other during compression of the suspension, in order to define a compression curve approximating a compression / traction curve optimal.
• the front of the bike is to the left and the suspension consists of four elements interconnected by four pivot links (A), (B), (C) and (D).
• the upper plate AB connected to the frame via the steering pin 1
• this suspension includes the axis of rotation of the front wheel O.
• the pivots A and B of the fork pivot 1 are located on either side of the axis of the pivoting connection between the fork pivot 1 and the frame of the cycle (not shown).
• this suspension is of deformable quadrilateral type (that is to say which is not a parallelogram, this deformable quadrilateral being ideally of the type described in EP 14 00 1362
• This type of suspension advantageously makes it possible to place the pivots (A), (B), (C) and (D) ideally so that the position of the Instantaneous Center of Rotation (CIR) of the fork (3) with respect to the pivot Fork (1), defined by the intersection of the straight lines (AD) and (CD), is located at the rear - with respect to the direction of movement of the cycle - of the trajectory drawn by the axis of the front wheel.
• the quadrilateral comprises the two opposite segments AD and BC which slightly diverge from each other towards the upper plate AB, and the segment CD is inclined with respect to the upper plate AB towards the axis of rotation of the front wheel.
• a deformable blade is installed between all points of the suspension moving away from each other during compression of the suspension, resulting for example a shock suffered by the front wheel during the movement of the cycle.
• the choice of the location of the blade depends on the space available, the displacement delta of the blade, the forces generated.
• the compression of the suspension as described above causes the fork to pivot about the pivot D (the point "O" rises, the point C rises slower than the point D, and the quadrilateral ABCD is deformed accordingly around the pivots A, B, C, D), pivoting of which results in a mutual spacing of the pivots (A) and (C) and a reconciliation of the pivots (B) and (D).
• the invention provides for mounting between the two pivots away from each other during the compression of the suspension, (A) and (C), an elastic element whose two ends are respectively mounted on these two pivots (A) and (C) and are stretched during the spacing of these two pivots.
• FIG. 11A A person skilled in the art easily identifies from FIG. 11A or from a comparison of the figures before and after soliciting the suspension (11B, 11C), which are the suspension parts that separate one of the other when the suspension is requested.
• the two pivots A and C deviate from each other. They were therefore retained as the connection points with the ends of the blade.
• the elastically deformable blade 2 occupies a curved rest state when the suspension is not stressed (FIG. 11B) and an active state when the suspension is biased (compressed (FIG. 11C).
• the blade 2 is thus "pulled” by its ends when the suspension is requested.
• This blade 2 which can be seen more clearly in FIGS. 2 and 4 to 9, is for example formed of a single-piece element which has a much lower flexural stiffness (normal moment at the median plane) (10, 1000 or even 10,000 times) than its rigidity in traction (according to the direction of the neutral fiber).
• An alternative to the one-piece structure of the blade is to design it as an assembly of a blade and its two connecting elements, alternative having the advantage of being less expensive than the one-piece blade.
• It comprises a central body in the form of a thick band, and ends shaped hollow cylinder section, connected to the transverse end edges of the strip parallel to their axis of revolution. It is in the hollow core of the ends that can be mounted connecting inserts for example metal 7.
• the blade 8 has a maximum curvature (smallest radii of curvature), its ends (coinciding with the pivots A and C) being brought closer to each other .
• the thickness variation directly influences the flexural strength and thus modifies the beginning of the curve.
• a local variation simple (such as the narrowing thickness 6 shown in Figure 3), multiple or progressive.
• the width has little influence on flexion but is defined according to tensile strength criteria. It is therefore possible to use a width variation to compensate, for example, a local decrease in thickness in order to maintain the same traction behavior.
• a width variation In the case of the use of fiber-based composite (carbon, glass, etc.) it is desired to keep the same number of fibers along the entire length of the blade so as not to interrupt them. The same section (mm 2 ) is then necessarily kept on the entire blade, which imposes an increase in width in the presence of a reduction in thickness.
• metal inserts 7 shown in FIG. 2 serving as connection means between the ends 3, 4 of the blade and the suspension parts which deviate from each other during compression of the suspension.
• the inserts are either directly the connecting pins or the supports / connector thereof.
• the material does not work in the same way in the thickness of the blade, it has advantageously been proposed a "sandwich" design:
• the neutral fiber works only in traction. It has no influence on flexural behavior.
• the material may be a thin fiber and very resistant to traction (such as high modulus carbon)
• the surface area is the one that acts the most on the bending characteristics.
• the material must have good elasticity and possibly good impact resistance, such as a high performance polymer, such as aromatic polyamides.
• the intermediate zone may have complex constraints depending on the design of the blade. This zone can participate in the dissipation of energy (foams, elastomer, etc.) and make it possible to filter vibrations.
• a conventional damper may be associated with the blade in accordance with Figs. 16A and 16B.
• the blade is an elastic element which by definition deforms and allows to recover the initial position but does not play the role of damper. That is, it does not dissipate / absorb energy (except for the particular sandwich design above).
• a conventional damper (hydraulic or gas) 8 is necessarily associated with the blade in the context of a suspension. If this association is not problematic, it is possible to integrate the damper 8 to the structure of the blade to further reduce the size and the number of parts required according to the following diagram in accordance with Figures 16A and 16B.
• the ends 3, 4 of the blade 2 are linked in movement with respectively the end of the piston rod 9 and the rear of the bottom wall of the tube 11 in which the piston is struggling.
• a composite blade having one or other of the aforementioned profiles, thickness, variable width, associated or not with a damper, can be integrated into a vehicle front suspension according to Figs. 11A-12B and / or a rear suspension according to Figs. 13A-15B.
• FIGS. 11A to 11C in which the blade is integrated in the quadrilateral and occupies a position that could be described as a high position, according to the example illustrated in FIGS. 12A and 12B, the blade is disposed in a "low position" .
• the ends 3, 4 of the blade are mounted respectively on an additional pivot E positioned at the end E of an arm DE extending one of the segments of the quadrilateral (in this case the upper arm AD) and on an additional pivot 11 positioned on the lower arm OD.
• the blade 2 initially occupying the curved rest state (FIG. A) has its ends stretched under the effect of the spacing from each other of the end E of the extension of the upper arm AD, and the lower arm OD ( Figure 12B).
• FIGS. 13A to 15B show the blade implanted within a rear suspension of a cycle.
• this suspension is integrated within a triangle ABC of a mountain bike or that of a frame of a motorcycle, this triangle being connected to the axis of the rear wheel O by an oscillating arm OD around a pivot D disposed on the rear segment BC of the triangle or any other fixed part of the frame.
• the blade according to the invention can be installed at any point away from each other of the structure of the suspension during its loading (lifting of the axis of rotation O of the rear wheel and pivoting of the oscillating arm OD around the pivot D), the choice of its location depending on the available space, the displacement delta of the blade, the forces generated.
• the blade is interposed between a pivot C coinciding with the lower vertex of the triangle ABC or any other fixed part, and an additional pivot 12 attached to the oscillating arm OD near the pivot D.
• This configuration requires a small number of parts for the integration of the blade (only the additional pivot 12 and the pivot C), as well as its reliability.
• FIGS. 14A, 14B use is made of an extension DE of the oscillating arm OD inside the triangle ABC.
• the blade is interposed between a pivot 13 coinciding with the end of the extension DE, and an additional pivot 14 positioned on the DB segment, the pivots 13 and 14 deviating from each other when the suspension is stressed.
• the advantage of this configuration is in particular to manage the length DE in order to reduce the efforts.
• the blade occupies a "floating" position because none of the ends is fixed relative to the frame of the vehicle.
• two additional segments 16 and 17 are articulated in pairs. around a pivot 18 by their contiguous ends, and respectively comprise an articulated end by means of a pivot 21 to the axis of rotation of the rear wheel.
• the pivots D, 21, 18, 19 form a deformable quadrilateral whose two segments OD and 17 deviate from each other when the suspension is stressed. It is between these two segments that the blade according to the invention is mounted by means of pivots 22.
• This configuration is widely used with conventional elastic systems because it makes it possible to manage the progressiveness of compression, but it is not necessary in the case of the use of a blade drawn from the invention, but quite possible for modify at least the existing structures while benefiting from the contributions of the invention.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Springs (AREA)
• Vehicle Body Suspensions (AREA)
• Axle Suspensions And Sidecars For Cycles (AREA)
• Vibration Prevention Devices (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=54066061

Family Applications (1)

Country Status (6)

Families Citing this family (10)

Family Cites Families (17)

• 2015
  • 2015-06-25 FR FR1555850A patent/FR3037865B1/fr active Active
• 2016
  • 2016-06-24 CN CN201680036702.2A patent/CN107709056A/zh active Pending
  • 2016-06-24 WO PCT/FR2016/051560 patent/WO2016207570A2/fr not_active Ceased
  • 2016-06-24 JP JP2018518793A patent/JP2018526285A/ja active Pending
  • 2016-06-24 EP EP16738484.1A patent/EP3313676A2/de not_active Withdrawn
  • 2016-06-24 US US15/738,493 patent/US10981620B2/en active Active

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