Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60G—VEHICLE SUSPENSION ARRANGEMENTS
  • B60G7/00—Pivoted suspension arms; Accessories thereof
  • B60G7/04—Buffer means for limiting movement of arms
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60G—VEHICLE SUSPENSION ARRANGEMENTS
  • B60G21/00—Interconnection systems for two or more resiliently-suspended wheels, e.g. for stabilising a vehicle body with respect to acceleration, deceleration or centrifugal forces
  • B60G21/02—Interconnection systems for two or more resiliently-suspended wheels, e.g. for stabilising a vehicle body with respect to acceleration, deceleration or centrifugal forces permanently interconnected
  • B60G21/04—Interconnection systems for two or more resiliently-suspended wheels, e.g. for stabilising a vehicle body with respect to acceleration, deceleration or centrifugal forces permanently interconnected mechanically
  • B60G21/05—Interconnection systems for two or more resiliently-suspended wheels, e.g. for stabilising a vehicle body with respect to acceleration, deceleration or centrifugal forces permanently interconnected mechanically between wheels on the same axle but on different sides of the vehicle, i.e. the left and right wheel suspensions being interconnected
  • B60G21/055—Stabiliser bars
  • B60G21/0551—Mounting means therefor
  • B60G21/0553—Mounting means therefor adjustable
• • 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
  • F16F9/00—Springs, vibration-dampers, shock-absorbers, or similarly-constructed movement-dampers using a fluid or the equivalent as damping medium
  • F16F9/32—Details
  • F16F9/48—Arrangements for providing different damping effects at different parts of the stroke
  • F16F9/49—Stops limiting fluid passage, e.g. hydraulic stops or elastomeric elements inside the cylinder which contribute to changes in fluid damping
• • 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
  • F16F9/00—Springs, vibration-dampers, shock-absorbers, or similarly-constructed movement-dampers using a fluid or the equivalent as damping medium
  • F16F9/32—Details
  • F16F9/58—Stroke limiting stops, e.g. arranged on the piston rod outside the cylinder
  • F16F9/585—Stroke limiting stops, e.g. arranged on the piston rod outside the cylinder within the cylinder, in contact with working fluid
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60G—VEHICLE SUSPENSION ARRANGEMENTS
  • B60G2204/00—Indexing codes related to suspensions per se or to auxiliary parts
  • B60G2204/40—Auxiliary suspension parts; Adjustment of suspensions
  • B60G2204/45—Stops limiting travel
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60G—VEHICLE SUSPENSION ARRANGEMENTS
  • B60G2204/00—Indexing codes related to suspensions per se or to auxiliary parts
  • B60G2204/40—Auxiliary suspension parts; Adjustment of suspensions
  • B60G2204/45—Stops limiting travel
  • B60G2204/4502—Stops limiting travel using resilient buffer
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60G—VEHICLE SUSPENSION ARRANGEMENTS
  • B60G2400/00—Indexing codes relating to detected, measured or calculated conditions or factors
  • B60G2400/05—Attitude
  • B60G2400/051—Angle
  • B60G2400/0511—Roll angle

Definitions

• the invention relates to a hydraulic suspension system of a vehicle, especially automobile.
• a hydraulic suspension system of a vehicle in particular a vehicle, comprises for each of the wheels of the vehicle a piston damper movable in its corresponding cylinder and interposed between the body and the wheel stub axle. of the vehicle.
• the role of this damper is to greatly limit the oscillations transmitted by the wheels to the vehicle body when the wheels encounter roughness or obstacles present on the road on which the vehicle is traveling, and to curb the cash movements in the dynamic actions like braking and turning.
• attack stroke In order to limit and brake the piston stroke of the damper in a compression stroke also called attack stroke, the latter comprises a compressible mechanical mechanical stop, or possibly hydraulic.
• the role of this attack stop is also to protect the chassis of the vehicle during the appearance of strong deflections of the corresponding wheel, due to incidents or significant obstacles, such as retarders type back-d donkey.
• the motor vehicles generally comprise on each wheel train an anti-roll bar having a transverse central portion forming a torsion bar, each end of which is connected to a suspension.
• an anti-roll bar having a transverse central portion forming a torsion bar, each end of which is connected to a suspension.
• the anti-roll bar adds on each suspension in case of roll of the body, a stiffness that adds to that of the suspension spring.
• the suspension is then firmer, which reduces the impression of comfort.
• the present invention aims to overcome the above disadvantages of the prior art.
• the invention relates to a hydraulic suspension system of a vehicle undercarriage, particularly automobile, according to claim 1.
• the invention also relates to a vehicle, including an automobile, comprising such a hydraulic suspension system.
• FIG. 1 A and 1 B respectively show a longitudinal sectional diagram of a damper of the prior art, and a graph illustrating the forces delivered by the suspension system as a function of the piston stroke of the damper in the damper cylinder;
• FIG. 3 represents a graph illustrating for the damper according to the prior art, the forces delivered by the suspension system as a function of the stroke of the damper piston, in a turn by adding the effects of a bar anti-roll;
• FIGS. 4A and 4B respectively represent a longitudinal sectional diagram of a shock absorber of a suspension system according to a first embodiment of the invention when the vehicle is at a reference attitude, and a graph illustrating the forces delivered by the suspension system corresponding to the position of the piston identified in FIG. 4A, the system being in a first state;
• FIGS. 5A and 5B respectively represent a longitudinal sectional diagram of a shock absorber of a suspension system according to the first embodiment of the invention when the vehicle is at a reference attitude, as well as a graph illustrating the the forces delivered by the suspension system corresponding to the position of the piston indicated in FIG. 5A, the system being in a second state
• FIGS. 6A and 6B respectively represent a longitudinal sectional diagram of a shock absorber of a suspension system according to a second embodiment of the invention when the vehicle is at a reference attitude, as well as a graph illustrating the the forces delivered by the suspension system corresponding to the position of the piston indicated in FIG. 6A, the system being in a first state
• FIGS. 5A and 5B respectively represent a longitudinal sectional diagram of a shock absorber of a suspension system according to the first embodiment of the invention when the vehicle is at a reference attitude, as well as a graph illustrating the the forces delivered by the suspension system corresponding to the position of the piston indicated in FIG. 6A, the system being in
• FIGS. 7A and 7B respectively represent a longitudinal sectional diagram of a shock absorber of a suspension system according to the second embodiment of the invention when the vehicle is at a reference attitude as well as a graph illustrating the forces delivered by the suspension system corresponding to the position of the piston indicated in FIG. 7A, the system being in a second state.
• the suspension of the vehicle comprises, for each wheel of the vehicle, a hydraulic damper 1 comprising a body 2 in the form of a cylinder and a piston 3 movable in the cylinder 2.
• This damper 1 is interposed between the body 6 of the vehicle and the corresponding wheel knuckle.
• each hydraulic damper 1 of the vehicle hydraulic suspension system can be described according to a damping law in which the force exerted by the damper 1 depends on the speed of movement of the corresponding wheel.
• the faster the piston 3 moves in the cylinder 2 of the damper the higher the braking of this piston, and the greater the force exerted by the damper 1 on the body 6 of the vehicle is important.
• the hydraulic suspension system also comprises, for each wheel of the vehicle, a suspension spring 17 mounted around the damper 1 and whose ends are respectively supported against the body 6 of the vehicle via a cup 18 and against a cup 19 secured to the cylinder 2 of the damper.
• the suspension spring 17 is an element of constant stiffness, the behavior of which can be described by a law according to which the force exerted by the spring 17 on the body 6 of the vehicle depends on its compression and therefore on the amplitude of the deflection of the vehicle. the corresponding wheel. In other words, the more the suspension spring 17 is compressed, the greater the force exerted on the body 6 of the vehicle is important.
• the suspension spring 17 essentially serves to carry the body 6 of the vehicle while allowing the deflections.
• the suspension system also comprises for each wheel of the vehicle two respectively mechanical 7 and hydraulic 9 attacking stops, as well as two respectively mechanical 16 and hydraulic 15 rebound stops.
• Each mechanical stop 7, 16 can be assimilated at a stiffness, and therefore exerts a force on the body 6 as a function of the displacement of the corresponding wheel.
• the force exerted on the body 6 of the vehicle by the mechanical stops respectively of attack 7 and relaxation 16 is even greater than the deflection in attack and relaxation of the corresponding wheel is important.
• Each hydraulic stop of attack 9 and relaxation 15 is for its part similar to a damper and therefore exerts a force on the body 6 of the vehicle according to the speed of travel of the corresponding wheel.
• the hydraulic damper 1 the force exerted on the body 6 of the vehicle by the hydraulic stops respectively of attack 9 and relaxation 15 is even greater than the speed of travel of the corresponding wheel is important.
• hydraulic attacking stops 9 and relaxation 15 are stops progressive effort that increases with the race, by the progressive reduction of fluid passages according to their race, which also gives an effort all the greater as the race is great.
• the mechanical attack abutment 7 is secured to one end of the cylinder 2 of the damper, and positioned axially between the end of the cylinder 2 of the damper and the body 6 of the vehicle. It also has an annular cross-section so as to be traversed by the rod 14 of the piston 3 of the damper 1.
• the mechanical attack stop 7 is compressed between the end of the cylinder 2 of the damper 1 and the body 6 of the vehicle so as to strongly slow the stroke of the piston 3 in the cylinder 2 of the damper.
• the mechanical attack abutment 7 is made of elastomer material having a very high stiffness constant, so that the force exerted by the mechanical attack abutment 7 on the body 6 of the vehicle increases very rapidly with the deflection in attack of the wheel.
• the hydraulic attack stop 9 is mounted in the compression chamber 4 of the cylinder 2 of the damper 1.
• the hydraulic attack abutment 9 comprises a piston 1 1 secured to the bottom bottom wall 12 of the cylinder 2 of the damper, and a cylinder 10 intended to be displaced along the piston 1 1 of the attack abutment 9 by the piston 3 of the damper 1 when it reaches the vicinity of the end of stroke attack.
• the cylinder 10 of the hydraulic abutment 7 forms a compression chamber 20 filled with hydraulic fluid, which is likely to escape from this chamber 20 by leaks around the piston 1 1 of the hydraulic abutment 9 when the piston 3 the damper moves the cylinder 10 of the hydraulic attack stop 9 towards the lower bottom wall 12 of the damper.
• the piston 3 of the damper 1 arriving near its end stroke attack is very quickly braked.
• the hydraulic abutment 9 comprises a return spring 21 surrounding the piston 1 1 of the hydraulic abutment 9 and whose ends are supported axially respectively against the bottom bottom wall 12 of the cylinder 2 of the absorber, and the annular end edge bordering the orifice of the cylinder 10 of the hydraulic stop 9.
• the return spring 21 allows the cylinder 10 of the hydraulic attack stop 9 to return to the position of rest, the piston 1 1 emerging from this cylinder, when the piston 3 of the damper 1 away from the cylinder 10 of the hydraulic stop 9.
• the hydraulic expansion stop 15 is in turn a floating piston surrounding the rod 14 of the damper 1 so as to maintain an annular space 23 between the rod 14 and the inner edge of the floating piston through which the hydraulic fluid is likely to circulate.
• the hydraulic expansion stop 15 is positioned in the expansion chamber 5 of the cylinder 2 of the damper, axially between the upper end wall 8 of the cylinder 2 of the damper through which the rod 14 of the damper and a collar 22 forming a valve secured to the rod 14 of the damper.
• the mechanical expansion stop 16 is in turn a high stiffness spring positioned in the expansion chamber 5 and whose ends are axially respectively bearing against the floating piston 15 and the upper end wall 8 of the cylinder 2 of the shock absorber 1.
• the vertical scale represents the stroke in millimeters of the piston 3 of the damper in the cylinder 2 of the damper 1 during deflections of the vehicle wheel.
• the horizontal scale is a visual scale representing the force exerted by each element of the hydraulic suspension at a wheel as a function of the stroke of the piston 3 in the cylinder 2 of the corresponding damper 1.
• the zero stroke corresponds to the position of the piston 3 of the damper 1 in the cylinder when the suspension of the vehicle does not undergo any other effort than that exerted by the mass of the vehicle.
• the vehicle is then at the reference base AR.
• the negative races of the piston 3 of the damper in the cylinder 2 correspond to deflections in attack of the wheel, that is to say that the suspension tends to compress and the body 6 of the vehicle to move closer to the road compared to the reference base AR.
• the positive strokes of the piston 3 of the shock absorber 1 in the cylinder 2 correspond to displacements in relaxation of the wheel, that is to say that the suspension tends to relax and the body 6 of the vehicle to move away from the road relative to the reference base AR.
• strokes in attack or relaxation of the piston 3 of the damper 1 between -15 mm and 15 mm from the reference base AR correspond to low energy DLE deflections which represent the solicitations the most frequent, encountered on roads of good quality.
• the mechanical attack stop 7 is compressed as soon as the stroke of the piston 3 of the damper 1 exceeds an attacking stroke of about 10 mm.
• the mechanical attack stop 7 intervenes quickly to slow the stroke of the piston 3 of the damper 1 from the beginning of the medium energy deflections DME.
• the piston 3 of the hydraulic damper 1 causes the displacement of the cylinder 10 of the hydraulic attack stopper 9 along its corresponding piston January 1, to quickly brake the piston 3 of the damper 1 in its corresponding cylinder 2 by adding a braking force depending on the speed to the braking force of the mechanical stop 7. This protects the body 6 of the vehicle against shocks in the end racing that could destroy elements.
• the anti-roll bar of the front or rear axle then sees a greater compression of the suspension on the outside of the turn, and less important on the other side, it then generates on each side a return force on the suspension, having a certain stiffness which will be added to that of the suspension spring 17.
• the force given by the stiffness of the suspension spring 17 has been superimposed on the force applied.
• the anti-roll bar 30 in the case of a turn on the same vehicle train having an average height which is the reference base AR.
• the force of the anti-roll bar 30 is zero for the central point 36 disposed on the reference base AR, the two suspensions being at this average height.
• the hydraulic suspension system also comprises for each wheel of the vehicle a mechanical attack stop 7b shorter than the mechanical attack stop 7 of the prior art, as well as an attacking abutment hydraulic 9b whose cylinder 10b has an amplitude of displacement along the corresponding piston 1 1b between its end stroke stroke and its limit end of travel between 40 and 60 mm. This displacement amplitude is greater than the displacement amplitude of the cylinder 10 of the hydraulic attack stop 9 of the prior art, which is of the order of 30 mm.
• the structure of the cylinder 10b of the hydraulic attack stop 9b is different, since the cylinder 10b comprises in its wall a plurality of through radial holes 13, and allowing the entry or exit of the hydraulic fluid of the compression chamber 4 of the cylinder 2 of the damper 1b when the piston 1 1b and the cylinder 10b of the hydraulic abutment 9b move relative to each other.
• the overall section of a smaller number of holes 13 through the cylinder 10b of the abutment hydraulic attack 9b decreases because an increasing number of through holes 13 are plugged by the piston 1 1 b of the hydraulic attack stop 9b as the cylinder 10b moves along the piston 1 1 b of the hydraulic attack stop 9b in the direction of the lower bottom wall 12 of the cylinder 2 of the damper 1b: this ensures a stronger braking of the piston 3 of the damper 1b in order to protect the body 6 and the frame of the vehicle.
• the hydraulic attack stop 9b dissipates the energy without accumulating it, thus avoiding any stimulus effect during low and medium energy deflections.
• the suspension system comprises a suspension spring 17b having a decreased stiffness relative to the suspension spring 17 shown in Figure 1 A.
• the decreased stiffness is represented by the straight line 42 which is less inclined than the straight line of the spring.
• the reduced stiffness of the suspension spring 17b gives a vertical natural oscillation frequency of the vehicle body which is less than 1, 2Hz, while the values usually accepted are between 1, 2 and 1, 4Hz.
• a natural oscillation frequency between 1 and 1, 1 Hz, which gives great flexibility to the suspension.
• the hydraulic suspension system according to the second embodiment of the invention also comprises for each wheel of the vehicle a mechanical expansion stop 16b longer than the mechanical expansion stop 16 of the prior art. Therefore, the floating piston of the hydraulic expansion stop 15b according to the second embodiment of the invention has an amplitude of displacement around the rod 14 of the damper 1b, between its rest position and its end position. running in relaxation, for example between 40 and 80 mm. This displacement amplitude is greater than the displacement amplitude of the floating piston of the hydraulic expansion stopper 15 of the prior art, which is of the order of 20 to 30 mm.
• the extension of the displacement amplitude of the hydraulic expansion stop 15b makes it possible to reduce the stiffness of the spring of the mechanical expansion stop 16b, so that it contributes little to the braking of the piston 3 of the shock absorber 1 b relaxation.
• the floating piston 15b of the hydraulic expansion stop is formed by an annular ring radially split over its entire thickness and intended to slide along the rod 14 of the damper 1b so as to maintain a space ring 23b between the rod 14 and the inner edge of the floating piston 15b, while the upper part of the expansion chamber 5 of the cylinder 2 of the damper 1b comprises a wall 2b of substantially frustoconical shape whose cross section decreases in the upper direction towards the wall 8 of the shock absorber 1b.
• the force exerted by the detent stops 15b, 16b on the vehicle body increases very gradually with the stroke of the floating piston 15b: as the floating piston 15b moves towards the upper end wall 8 of the cylinder 2 of the damper 1b along the frustoconical wall 2b, the slot and the annular space 23b of the floating piston 15b closes gradually, thereby decreasing the passage section of the hydraulic fluid.
• This therefore ensures a variable damping according to the stroke of the floating piston 15b, significantly improving control of the vertical movements of the vehicle body, and thus the comfort of the vehicle.
• the damping level of the shock absorber 1b is reduced in attack and relaxation, below that usually used for the same type of vehicle, shown in FIG. a width of the reduced effort.
• the decrease in the damping level of the shock absorber 1b corresponds substantially on average to this stroke, to the value of the additional damping. given by the hydraulic attack stop 7b, so as to preserve the control of the body movements 6 for this type of deflections.
• the system according to the invention comprises a switching means 100 allowing, at the choice of the driver or according to an automated logic to switch the anti-roll bar 30 between two states A and B.
• the configuration as described is not limited to the embodiments described above and shown in the figures. It has been given only as a non-limiting example. Multiple modifications can be made without departing from the scope of the invention.
• the invention is not limited to a single hydraulic thrust bearing configuration 9b.
• a hydraulic attack stopper 9b whose cylinder 10b is secured to the inner walls of the compression chamber 4 of the damper 1b and whose piston 1 1b is intended to be moved in its corresponding cylinder 10b by the piston 3 of the shock absorber 1b.
• any type of hydraulic attack stopper 9b known and adapted to be housed in the compression chamber 4 of a damper 1b may be considered.

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• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Vehicle Body Suspensions (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=58361037

Family Applications (1)

Country Status (3)

Families Citing this family (4)

Family Cites Families (16)

• 2017
  • 2017-03-02 WO PCT/FR2017/050472 patent/WO2017168065A1/fr active Application Filing
  • 2017-03-02 EP EP17712212.4A patent/EP3436291A1/fr not_active Withdrawn
  • 2017-03-02 CN CN201780020929.2A patent/CN108883678A/zh active Pending

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