WO2017162948A1 - Hydraulic suspension system for a vehicle - Google Patents

Hydraulic suspension system for a vehicle Download PDF

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Publication number
WO2017162948A1
WO2017162948A1 PCT/FR2017/050476 FR2017050476W WO2017162948A1 WO 2017162948 A1 WO2017162948 A1 WO 2017162948A1 FR 2017050476 W FR2017050476 W FR 2017050476W WO 2017162948 A1 WO2017162948 A1 WO 2017162948A1
Authority
WO
WIPO (PCT)
Prior art keywords
damper
piston
cylinder
vehicle
hydraulic
Prior art date
Application number
PCT/FR2017/050476
Other languages
French (fr)
Inventor
Nicolas BERLINGER
Frederic Guingand
Original Assignee
Psa Automobiles S.A.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from FR1652615A external-priority patent/FR3049233B1/en
Priority claimed from FR1652614A external-priority patent/FR3049229B1/en
Application filed by Psa Automobiles S.A. filed Critical Psa Automobiles S.A.
Priority to EP17713725.4A priority Critical patent/EP3433114A1/en
Priority to CN201780019607.6A priority patent/CN109070677B/en
Publication of WO2017162948A1 publication Critical patent/WO2017162948A1/en

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60G—VEHICLE SUSPENSION ARRANGEMENTS
    • B60G15/00—Resilient suspensions characterised by arrangement, location or type of combined spring and vibration damper, e.g. telescopic type
    • B60G15/02—Resilient suspensions characterised by arrangement, location or type of combined spring and vibration damper, e.g. telescopic type having mechanical spring
    • B60G15/06—Resilient suspensions characterised by arrangement, location or type of combined spring and vibration damper, e.g. telescopic type having mechanical spring and fluid damper
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60G—VEHICLE SUSPENSION ARRANGEMENTS
    • B60G17/00—Resilient suspensions having means for adjusting the spring or vibration-damper characteristics, for regulating the distance between a supporting surface and a sprung part of vehicle or for locking suspension during use to meet varying vehicular or surface conditions, e.g. due to speed or load
    • B60G17/015—Resilient suspensions having means for adjusting the spring or vibration-damper characteristics, for regulating the distance between a supporting surface and a sprung part of vehicle or for locking suspension during use to meet varying vehicular or surface conditions, e.g. due to speed or load the regulating means comprising electric or electronic elements
    • B60G17/016—Resilient suspensions having means for adjusting the spring or vibration-damper characteristics, for regulating the distance between a supporting surface and a sprung part of vehicle or for locking suspension during use to meet varying vehicular or surface conditions, e.g. due to speed or load the regulating means comprising electric or electronic elements characterised by their responsiveness, when the vehicle is travelling, to specific motion, a specific condition, or driver input
    • B60G17/0162—Resilient suspensions having means for adjusting the spring or vibration-damper characteristics, for regulating the distance between a supporting surface and a sprung part of vehicle or for locking suspension during use to meet varying vehicular or surface conditions, e.g. due to speed or load the regulating means comprising electric or electronic elements characterised by their responsiveness, when the vehicle is travelling, to specific motion, a specific condition, or driver input mainly during a motion involving steering operation, e.g. cornering, overtaking
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60G—VEHICLE SUSPENSION ARRANGEMENTS
    • B60G17/00—Resilient suspensions having means for adjusting the spring or vibration-damper characteristics, for regulating the distance between a supporting surface and a sprung part of vehicle or for locking suspension during use to meet varying vehicular or surface conditions, e.g. due to speed or load
    • B60G17/015—Resilient suspensions having means for adjusting the spring or vibration-damper characteristics, for regulating the distance between a supporting surface and a sprung part of vehicle or for locking suspension during use to meet varying vehicular or surface conditions, e.g. due to speed or load the regulating means comprising electric or electronic elements
    • B60G17/018—Resilient suspensions having means for adjusting the spring or vibration-damper characteristics, for regulating the distance between a supporting surface and a sprung part of vehicle or for locking suspension during use to meet varying vehicular or surface conditions, e.g. due to speed or load the regulating means comprising electric or electronic elements characterised by the use of a specific signal treatment or control method
    • B60G17/0185—Resilient suspensions having means for adjusting the spring or vibration-damper characteristics, for regulating the distance between a supporting surface and a sprung part of vehicle or for locking suspension during use to meet varying vehicular or surface conditions, e.g. due to speed or load the regulating means comprising electric or electronic elements characterised by the use of a specific signal treatment or control method for failure detection
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60G—VEHICLE SUSPENSION ARRANGEMENTS
    • B60G17/00—Resilient suspensions having means for adjusting the spring or vibration-damper characteristics, for regulating the distance between a supporting surface and a sprung part of vehicle or for locking suspension during use to meet varying vehicular or surface conditions, e.g. due to speed or load
    • B60G17/06—Characteristics of dampers, e.g. mechanical dampers
    • B60G17/08—Characteristics of fluid dampers
    • 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
    • B60G2202/00—Indexing codes relating to the type of spring, damper or actuator
    • B60G2202/30—Spring/Damper and/or actuator Units
    • B60G2202/31—Spring/Damper and/or actuator Units with the spring arranged around the damper, e.g. MacPherson strut
    • B60G2202/312—The spring being a wound spring
    • 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
    • B60G2400/20—Speed
    • B60G2400/204—Vehicle speed
    • 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
    • B60G2400/40—Steering conditions
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60G—VEHICLE SUSPENSION ARRANGEMENTS
    • B60G2800/00—Indexing codes relating to the type of movement or to the condition of the vehicle and to the end result to be achieved by the control action
    • B60G2800/80—Detection or control after a system or component failure

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 present invention aims to overcome the above disadvantages of the prior art. [007] To achieve this object, the invention relates to a hydraulic suspension system of a vehicle running gear, particularly automobile, according to claim 1.
  • the invention also relates to a vehicle, including automobile, comprising such a hydraulic suspension system.
  • FIGS. 2A and 2B respectively represent a longitudinal sectional diagram of a controlled damper of a suspension system according to a first 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. 2A;
  • FIG. 3 represents a graph illustrating different stress curves for a controlled damper of the suspension system according to the invention.
  • FIGS. 4A and 4B respectively represent a longitudinal sectional diagram of a controlled damper 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 forces delivered by the suspension system corresponding to the position of the piston identified in FIG. 4A.
  • 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 and hydraulic driving abutments 7 and 9 respectively mechanical and hydraulic 16 and hydraulic expansion stops respectively.
  • Each mechanical stop 7, 16 is similar to a stiffness, and therefore exerts a force on the body 6 according to the movement 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 attacking stop 9 and relaxation 15 is in turn assimilable to a damper and therefore exerts a force on the body 6 of the vehicle in depending on the speed of travel of the corresponding wheel.
  • 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.
  • the hydraulic attacking stops 9 and the trigger 15 are progressive force stops which increase as a function of the stroke, by the progressive reduction of the fluid passages according to their stroke, which also gives an effort of as much bigger than the race is big.
  • 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 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 lower 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.
  • races in piston stroke 3 of the damper 1 between -15 mm and -50 mm from the reference base AR, and strokes piston 3 of the damper 1 between 15 mm and 50 mm from the reference base AR correspond to medium energy DME deflections which represent also frequent solicitations.
  • races in piston attack 3 of the damper 1 beyond -50 mm from the reference base AR, up to the maximum of -80 mm, and races in piston expansion 3 of the damper 1 greater than 50 mm from the reference base AR, up to a maximum of 1 10 mm, correspond to high energy DHE deflections which represent infrequent solicitations. These stresses are encountered especially when the wheels cross a major hurdle-type retarder in the back of a donkey, or a relatively deep pothole.
  • the mechanical attack stop 7 is compressed as soon as the stroke of the piston 3 of the damper 1 exceeds an attack 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 stop 9 along its corresponding piston 1 1, to quickly brake the piston 3 of the damper 1 in its cylinder 2 corresponding by adding a braking force depending on the speed to the braking force of the mechanical stop 7.
  • each wheel of the vehicle a shock absorber 1b, a suspension spring 17 and two respective mechanical 16 and hydraulic expansion stops 15 as described above.
  • the hydraulic suspension system according to the invention also comprises for each wheel of the vehicle a mechanical attack abutment 7b shorter than the mechanical attack abutment 7 of the prior art, as well as an attack 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 range of motion 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 piston 3 of the hydraulic damper 1b exceeds an attacking stroke CA1 of between 0 and 20 mm, preferably 10 mm, the latter causes the displacement of the cylinder 10b of the hydraulic attack stop 9b along its corresponding piston 1 1 b.
  • the overall section of a large number of the holes 13 passing through the cylinder 10b of the hydraulic thrust bearing 9b is sufficiently high to ensure gentle braking of the piston 3 of the shock absorber 1.
  • 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 attack abutment 7b is compressed and participates in strengthening the braking of the piston 3 of the damper 1.
  • the discontinuity of the force exerted by the suspension system during its compression which generates discomfort for the passengers of the vehicle, is greatly reduced thanks to the hydraulic attack stop 9b, whose cylinder 10b has an elongated displacement amplitude, which acts before the mechanical attack stop 7b.
  • the force exerted by the hydraulic attack stop 9b depending both on the speed and the displacement amplitude of the piston 3 of the shock absorber 1b in its cylinder 2, the braking of the piston 3 of the The shock absorber is progressively adapted to the amplitude and the speed of its travel in the cylinder 2, in particular for the medium energy DME deflections, which also has a positive effect on passenger comfort.
  • the hydraulic attack stop 9b dissipates the energy without accumulating it, thus avoiding any stimulus effect during low and medium energy deflections.
  • the damper 1b further comprises piloting means 30 which modify the level of effort generated by the displacement of the piston 3 in the cylinder 2, according to programmed damping laws, acting by an electrical connection connected to a calculator 32.
  • the variable level of effort of the displacement of the piston 3 in the cylinder 2 is indicated in FIG. 2B by a variable width of the rectangular zone representing the force of the damper 1b.
  • the computer 32 sends a signal to the control means 30, in particular a current of variable intensity, to change the fluid passages on each side of the piston 3 of the damper 1b in order to vary in real time the level of effort and thus the damping of the oscillations of the suspension.
  • the computer 32 may comprise a limited number of damping laws, in particular only two predefined laws controlled by a current or an absence of current, which represents a very simple system, or a continuous range of variation of the level of current. 'amortization.
  • 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 a displacement amplitude around the rod 14 of the damper 1, between its rest position and its end position. relaxation stroke, 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 in relaxation.
  • the floating piston 15b of the hydraulic expansion stop is formed by an annular ring radially split over its entire thickness and designed to slide along the rod 14 of the damper 1 so as to maintain an annular space. 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 1 comprises a wall 2b of substantially frustoconical shape whose cross section decreases in the upper direction towards the wall 8 of the damper 1.
  • 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 1 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 horizontal axis represents the displacement velocity V of the piston 3 in the cylinder 2, expressed in meters per second
  • the axis vertical represents the force expressed in daN on this piston.
  • Different damping laws 34 are applied for variable currents applied in the control means 30, presented for an increment of the current of 0.1 A, which range from a very low damping 36 between -75 and +150 daN for a current of 0.4 A, with a high damping 38 between -600 and + 650daN for a current of 1, 6A .
  • control means 30 In the case of a lack of current in the control means 30, for example following a failure of the computer 32, these control means are provided to automatically enter a state giving an average damping law 40 which allows to continue the journey with a compromise between comfort and safety which is sufficient.
  • the hydraulic suspension system according to the invention comprises existing techniques arranged in a new combination, it can be easily developed and manufactured with reduced costs, using existing production technologies.
  • the configuration as described is not limited to the embodiments described above and shown in Figures 2A, 2B, 4A and 4B. It was not given 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 1.
  • 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)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Fluid-Damping Devices (AREA)
  • Vehicle Body Suspensions (AREA)

Abstract

The invention relates to a hydraulic suspension system for a motor vehicle, comprising a hydraulic compression abutment (9b), the piston and cylinder of which move relative to one another via the piston of a damper (1b) when the damper piston reaches a first compression position, and a mechanical compression abutment (7b) that is compressed between the damper cylinder and the vehicle body when the damper piston reaches a second compression position in the damper cylinder that is greater than the first compression position, said suspension system further comprising a computer (32) that acts on control means (30) for the damper (1b) which modify the amount of the load generated by the movement of the piston in the cylinder. The invention applies to the automotive industry.

Description

SYSTEME DE SUSPENSION HYDRAULIQUE D'UN VEHICULE  HYDRAULIC SUSPENSION SYSTEM OF A VEHICLE
[001 ] L'invention concerne un système de suspension hydraulique d'un véhicule, notamment automobile. [001] The invention relates to a hydraulic suspension system of a vehicle, especially automobile.
[002] De manière connue en soi, un système de suspension hydraulique d'un véhicule, notamment automobile, comprend pour chacune des roues du véhicule un amortisseur à piston mobile dans son cylindre correspondant et interposé entre la caisse et le porte- fusée de roue du véhicule. Le rôle de cet amortisseur est de fortement limiter les oscillations transmises par les roues à la caisse du véhicule lorsque les roues rencontrent des aspérités ou des obstacles présents sur la route sur laquelle le véhicule circule, et de freiner les mouvements de caisse dans les actions dynamiques comme les freinages et les virages. [002] In a manner known per se, 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.
[003] De manière à limiter et freiner la course du piston de l'amortisseur en course de compression appelée aussi course d'attaque, ce dernier comprend une butée d'attaque mécanique compressible, ou éventuellement hydraulique. Le rôle de cette butée d'attaque est également de protéger le châssis du véhicule lors de l'apparition de forts débattements de la roue correspondante, dus à des incidents ou à des obstacles importants, comme par exemple les ralentisseurs du type dos-d'âne. [003] 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.
[004] Il est notamment connu du document FR 2995048 une butée d'attaque hydraulique à piston mobile dans son cylindre correspondant, et dont le piston est destiné à être déplacé par le piston de l'amortisseur lorsque ce dernier approche de sa fin de course. [004] It is known in particular from FR 2995048 a hydraulic piston stop piston movable in its corresponding cylinder, and whose piston is intended to be moved by the piston of the damper when the latter approaches its end of course .
[005] Cependant, dans les cas de courses importantes du piston de l'amortisseur qui sont majoritairement de nature incidentelle, le confort de la suspension n'est pas une priorité au regard de la préservation de l'intégrité mécanique du véhicule. Pour cette raison, la butée d'attaque est généralement très raide et génère des discontinuités d'efforts brutales. Le confort pour les occupants du véhicule en est alors fortement pénalisé dans ces situations. [005] However, in cases of major strokes of the piston of the damper which are mainly of an incidental nature, the comfort of the suspension is not a priority with regard to the preservation of the mechanical integrity of the vehicle. For this reason, the attack stop is usually very stiff and generates discontinuities of brutal efforts. Comfort for the occupants of the vehicle is then strongly penalized in these situations.
[006] La présente invention a pour but de pallier les inconvénients ci-dessus de l'art antérieur. [007] Pour atteindre ce but, l'invention concerne un système de suspension hydraulique d'un train roulant de véhicule, notamment automobile, conforme à la revendication 1 . The present invention aims to overcome the above disadvantages of the prior art. [007] To achieve this object, the invention relates to a hydraulic suspension system of a vehicle running gear, particularly automobile, according to claim 1.
[008] D'autres caractéristiques sont énoncées dans les revendications dépendantes. [008] Other features are set forth in the dependent claims.
[009] L'invention concerne également un véhicule, notamment automobile, comprenant un tel système de suspension hydraulique. [009] The invention also relates to a vehicle, including automobile, comprising such a hydraulic suspension system.
[0010] L'invention sera mieux comprise, et d'autres buts, caractéristiques, détails et avantages de celle-ci apparaîtront plus clairement dans la description explicative qui va suivre faite en référence aux dessins annexés donnés uniquement à titre d'exemple illustrant un art antérieur et deux modes de réalisation de l'invention, dans lesquels : - Les figures 1 A et 1 B représentent respectivement un schéma en coupe longitudinale d'un amortisseur de l'art antérieur, ainsi qu'un graphe illustrant les efforts délivrés par le système de suspension en fonction de la course du piston de l'amortisseur dans le cylindre de l'amortisseur ; The invention will be better understood, and other objects, features, details and advantages thereof will appear more clearly in the explanatory description which follows with reference to the accompanying drawings given solely by way of example illustrating a prior art and two embodiments of the invention, in which: - Figures 1 A and 1 B respectively represent a longitudinal sectional diagram of a damper of the prior art, and a graph illustrating the forces delivered by the suspension system according to the stroke of the piston of the damper in the cylinder of the damper;
- Les figures 2A et 2B représentent respectivement un schéma en coupe longitudinale d'un amortisseur piloté d'un système de suspension selon un premier mode de réalisation de l'invention lorsque le véhicule est à une assiette de référence, ainsi qu'un graphe illustrant les efforts délivrés par le système de suspension correspondant à la position du piston repéré à la figure 2A ; FIGS. 2A and 2B respectively represent a longitudinal sectional diagram of a controlled damper of a suspension system according to a first 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. 2A;
- La figure 3 représente un graphe illustrant différentes courbes d'effort pour un amortisseur piloté du système de suspension selon l'invention ; et FIG. 3 represents a graph illustrating different stress curves for a controlled damper of the suspension system according to the invention; and
- Les figures 4A et 4B représentent respectivement un schéma en coupe longitudinale d'un amortisseur piloté d'un système de suspension selon un second mode de réalisation de l'invention lorsque le véhicule est à une assiette de référence, ainsi qu'un graphe illustrant les efforts délivrés par le système de suspension correspondant à la position du piston repéré à la figure 4A. FIGS. 4A and 4B respectively represent a longitudinal sectional diagram of a controlled damper 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 forces delivered by the suspension system corresponding to the position of the piston identified in FIG. 4A.
[001 1 ] En référence à la figure 1 A, un système de suspension hydraulique d'un véhicule, notamment automobile, va maintenant être décrit. [001 1] Referring to Figure 1 A, a hydraulic suspension system of a vehicle, including automotive, will now be described.
[0012] La suspension du véhicule comprend, pour chaque roue du véhicule, un amortisseur hydraulique 1 comprenant un corps 2 en forme de cylindre et un piston 3 mobile dans le cylindre 2. Cet amortisseur 1 est interposé entre la caisse 6 du véhicule et le porte-fusée de roue correspondant. Le piston 3, solidaire d'une première extrémité d'une tige 14 dont l'autre extrémité est reliée à la caisse 6 du véhicule, délimite dans le cylindre 2 deux chambres 4, 5 respectivement de compression et de détente, entre lesquelles du fluide hydraulique incompressible (huile) compris dans le cylindre 2, est échangé en circulant au travers de perçages non représentés du piston 3 qui freine ce passage, au gré des mouvements de ce dernier dans le cylindre 2. 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. The piston 3, integral with a first end of a rod 14 whose other end is connected to the body 6 of the vehicle, defines in the cylinder 2 two chambers 4, 5 respectively of compression and expansion, between which fluid incompressible hydraulic (oil) included in the cylinder 2, is exchanged by circulating through holes not shown piston 3 which brakes this passage, according to the movements of the latter in the cylinder 2.
[0013] Le comportement de chaque amortisseur hydraulique 1 du système de suspension hydraulique du véhicule peut être décrit selon une loi d'amortissement dans laquelle l'effort exercé par l'amortisseur 1 dépend de la vitesse de débattement de la roue correspondante. Autrement dit, plus le piston 3 se déplace rapidement dans le cylindre 2 de l'amortisseur, plus le freinage de de ce piston est élevé, et plus l'effort exercé par l'amortisseur 1 sur la caisse 6 du véhicule est important. The behavior of 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. In other words, 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.
[0014] Le système de suspension hydraulique comprend également, pour chaque roue du véhicule, un ressort de suspension 17 monté autour de l'amortisseur 1 et dont les extrémités sont en appui respectivement contre la caisse 6 du véhicule par l'intermédiaire d'une coupelle 18 et contre une coupelle 19 solidaire du cylindre 2 de l'amortisseur. Le ressort de suspension 17 est un élément de raideur constante, dont le comportement peut être décrit par une loi selon laquelle l'effort exercé par le ressort 17 sur la caisse 6 du véhicule dépend de sa compression et donc de l'amplitude du débattement de la roue correspondante. Autrement dit, plus le ressort de suspension 17 est comprimé, plus l'effort exercé sur la caisse 6 du véhicule est important. Le ressort de suspension 17 permet essentiellement de porter la caisse 6 du véhicule tout en autorisant les débattements. 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.
[0015] Le système de suspension comprend également pour chaque roue du véhicule deux butées d'attaque respectivement mécanique 7 et hydraulique 9, ainsi que deux butées de détente respectivement mécanique 16 et hydraulique 15. The suspension system also comprises, for each wheel of the vehicle, two respectively mechanical and hydraulic driving abutments 7 and 9 respectively mechanical and hydraulic 16 and hydraulic expansion stops respectively.
[0016] Chaque butée mécanique 7, 16 est assimilable à une raideur, et exerce donc un effort sur la caisse 6 en fonction du débattement de la roue correspondante. De la même manière que le ressort de suspension 17, l'effort exercé sur la caisse 6 du véhicule par les butées mécaniques respectivement d'attaque 7 et de détente 16 est d'autant plus grand que le débattement en attaque et en détente de la roue correspondante est important. Each mechanical stop 7, 16 is similar to a stiffness, and therefore exerts a force on the body 6 according to the movement of the corresponding wheel. In the same way as the suspension spring 17, 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.
[0017] Chaque butée hydraulique d'attaque 9 et de détente 15 est quant à elle assimilable à un amortisseur et exerce donc un effort sur la caisse 6 du véhicule en fonction de la vitesse du débattement de la roue correspondante. De la même manière que l'amortisseur hydraulique 1 , l'effort exercé sur la caisse 6 du véhicule par les butées hydraulique respectivement d'attaque 9 et de détente 15 est d'autant plus grand que la vitesse du débattement de la roue correspondante est importante. [0018] De plus les butées hydrauliques d'attaque 9 et de détente 15 sont des butées à effort progressif qui augmente en fonction de la course, par la réduction progressive des passages de fluides suivant leur course, ce qui donne aussi un effort d'autant plus grand que la course est grande. Each hydraulic attacking stop 9 and relaxation 15 is in turn assimilable to a damper and therefore exerts a force on the body 6 of the vehicle in depending on the speed of travel of the corresponding wheel. In the same way as 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. In addition, the hydraulic attacking stops 9 and the trigger 15 are progressive force stops which increase as a function of the stroke, by the progressive reduction of the fluid passages according to their stroke, which also gives an effort of as much bigger than the race is big.
[0019] En référence à la figure 1 A, la butée d'attaque mécanique 7 est solidaire d'une extrémité du cylindre 2 de l'amortisseur, et positionnée axialement entre cette extrémité du cylindre 2 de l'amortisseur et la caisse 6 du véhicule. Elle présente en outre une section transversale annulaire de manière à être traversée par la tige 14 du piston 3 de l'amortisseur 1 . Ainsi, quand le piston 3 dépasse une certaine course en attaque, la butée d'attaque mécanique 7 est comprimée entre l'extrémité du cylindre 2 de l'amortisseur 1 et la caisse 6 du véhicule de manière à fortement freiner la course du piston 3 dans le cylindre 2 de l'amortisseur. Referring to Figure 1 A, 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. Thus, when the piston 3 exceeds a certain stroke in attack, 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.
[0020] De préférence, la butée d'attaque mécanique 7 est en matériau élastomère présentant une très forte constante de raideur, de sorte que l'effort exercé par la butée d'attaque mécanique 7 sur la caisse 6 du véhicule augmente très rapidement avec le débattement en attaque de la roue. Preferably, 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.
[0021 ] La butée d'attaque hydraulique 9 est montée dans la chambre de compression 4 du cylindre 2 de l'amortisseur 1 . La butée d'attaque hydraulique 9 comprend un piston 1 1 solidaire de la paroi inférieure de fond 12 du cylindre 2 de l'amortisseur, et un cylindre 10 destiné à être déplacé le long du piston 1 1 de la butée d'attaque 9 par le piston 3 de l'amortisseur 1 quand celui-ci arrive au voisinage de la fin de course en attaque. Le cylindre 10 de la butée hydraulique 7 forme une chambre de compression 20 remplie du fluide hydraulique, qui est susceptible de s'échapper de cette chambre 20 par des fuites autour du piston 1 1 de la butée d'attaque hydraulique 9 lorsque le piston 3 de l'amortisseur déplace le cylindre 10 de la butée d'attaque hydraulique 9 en direction de la paroi inférieure de fond 12 de l'amortisseur. Ainsi, le piston 3 de l'amortisseur 1 arrivant au voisinage de sa fin de course en attaque est très rapidement freiné. [0022] En outre, la butée d'attaque hydraulique 9 comprend un ressort de rappel 21 entourant le piston 1 1 de la butée hydraulique 9 et dont les extrémités sont en appui axialement contre respectivement la paroi inférieure de fond 12 du cylindre 2 de l'amortisseur, et le bord annulaire d'extrémité bordant l'orifice du cylindre 10 de la butée hydraulique 9. De la sorte, le ressort de rappel 21 permet au cylindre 10 de la butée d'attaque hydraulique 9 de revenir à la position de repos, le piston 1 1 ressortant de ce cylindre, lorsque le piston 3 de l'amortisseur 1 s'éloigne du cylindre 10 de la butée hydraulique 9. 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. Thus, the piston 3 of the damper 1 arriving near its end stroke attack is very quickly braked. In addition, 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 lower 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. In this way, 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.
[0023] La butée de détente hydraulique 15 est quant à elle un piston flottant entourant la tige 14 de l'amortisseur 1 de manière à conserver un espace annulaire 23 entre la tige 14 et le bord interne du piston flottant au travers duquel le fluide hydraulique est susceptible de circuler. La butée de détente hydraulique 15 est positionnée dans la chambre de détente 5 du cylindre 2 de l'amortisseur, axialement entre la paroi d'extrémité supérieure 8 du cylindre 2 de l'amortisseur traversée par la tige 14 de l'amortisseur et une collerette 22 formant clapet solidaire de la tige 14 de l'amortisseur. La butée de détente mécanique 16 est quant à elle un ressort à forte raideur positionné dans la chambre de détente 5 et dont les extrémités sont axialement en appui respectivement contre le piston flottant 15 et la paroi d'extrémité supérieure 8 du cylindre 2 de l'amortisseur 1 . 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.
[0024] Lorsque le piston 3 de l'amortisseur hydraulique 1 se déplace au voisinage de sa fin de course en détente, la collerette 22 formant clapet déplace le piston flottant 15 en direction de la paroi d'extrémité supérieure 8 du cylindre 2 de l'amortisseur 1 . Le piston flottant 15 se déplaçant comprime alors simultanément la butée de détente mécanique 16. En outre, la collerette 22 formant clapet, en entrant en contact avec le piston flottant 15, obture l'espace 23 entre le bord interne du piston flottant 15 et la tige 14 ce qui réduit la section permettant le passage du fluide du dessus de ce piston flottant vers le dessous, augmentant ainsi la résistance de la butée de détente hydraulique au déplacement vers la paroi d'extrémité supérieure 8 du cylindre 2 de l'amortisseur 1 . Ainsi, le piston 3 de l'amortisseur hydraulique 1 arrivant au voisinage de sa fin de course est très rapidement freiné par les deux butées de détente 15, 16. [0025] En référence au graphe de la figure 1 B, l'agencement des butées d'attaque 7, 9 et de détente 15, 16 en fonction de la course du piston 3 de l'amortisseur 1 dans le cylindre 2 de l'amortisseur 1 va être décrit. [0026] L'échelle verticale représente la course en millimètres du piston 3 de l'amortisseur dans le cylindre 2 de l'amortisseur 1 lors des débattements de la roue du véhicule. L'échelle horizontale est une échelle visuelle représentant l'effort exercé par chaque élément de la suspension hydraulique au niveau d'une roue en fonction de la course du piston 3 dans le cylindre 2 de l'amortisseur 1 correspondant. La course nulle (zéro millimètres) correspond à la position du piston 3 de l'amortisseur 1 dans le cylindre lorsque la suspension du véhicule ne subit d'autre effort que celui exercé par la masse du véhicule. Le véhicule se trouve alors à l'assiette de référence AR. When the piston 3 of the hydraulic damper 1 moves in the vicinity of its end of stroke relaxation, the flange 22 forming the valve moves the floating piston 15 towards the upper end wall 8 of the cylinder 2 of the shock absorber 1. The floating piston 15 moving simultaneously simultaneously compresses the mechanical expansion stop 16. In addition, the collar 22 forming a valve, coming into contact with the floating piston 15, closes the space 23 between the inner edge of the floating piston 15 and the rod 14 which reduces the section allowing the passage of the fluid from the top of the floating piston towards the bottom, thus increasing the resistance of the hydraulic expansion stop to the displacement towards the upper end wall 8 of the cylinder 2 of the damper 1 . Thus, the piston 3 of the hydraulic damper 1 arriving near its end of stroke is very quickly braked by the two stops of relaxation 15, 16. [0025] With reference to the graph of Figure 1 B, the arrangement of driving abutments 7, 9 and trigger 15, 16 depending on the stroke of the piston 3 of the damper 1 in the cylinder 2 of the damper 1 will be described. 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 (zero millimeters) 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.
[0027] Les courses négatives du piston 3 de l'amortisseur dans le cylindre 2 correspondent à des débattements en attaque de la roue, c'est-à-dire que la suspension a tendance à se comprimer et la caisse 6 du véhicule à se rapprocher de la route par rapport à l'assiette de référence AR. A l'inverse, les courses positives du piston 3 de l'amortisseur 1 dans le cylindre 2 correspondent à des débattements en détente de la roue, c'est-à-dire que la suspension a tendance à se détendre et la caisse 6 du véhicule à s'éloigner de la route par rapport à l'assiette de référence 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. Conversely, 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.
[0028] On considère que des courses en attaque ou en détente de piston 3 de l'amortisseur 1 comprises entre -15 mm et 15 mm à partir de l'assiette de référence AR correspondent à des débattements de faible énergie DLE qui représentent les sollicitations les plus fréquentes, rencontrées sur les routes de bonne qualité. [0029] On considère que des courses en attaque de piston 3 de l'amortisseur 1 comprises entre -15 mm et -50 mm à partir de l'assiette de référence AR, et des courses en détente de piston 3 de l'amortisseur 1 comprises entre 15 mm et 50 mm à partir de l'assiette de référence AR, correspondent à des débattements de moyenne énergie DME qui représentent des sollicitations également fréquentes. Ces sollicitations sont rencontrées sur les routes légèrement dégradées, où lorsque les roues franchissent des petits obstacles, comme par exemple des petits ralentisseurs. It is considered that 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. It is considered that races in piston stroke 3 of the damper 1 between -15 mm and -50 mm from the reference base AR, and strokes piston 3 of the damper 1 between 15 mm and 50 mm from the reference base AR, correspond to medium energy DME deflections which represent also frequent solicitations. These stresses are encountered on slightly degraded roads, where when the wheels cross small obstacles, such as small speed bumps.
[0030] Enfin, on considère que des courses en attaque de piston 3 de l'amortisseur 1 au- delà de -50 mm à partir de l'assiette de référence AR, jusqu'au maximum de -80 mm, et des courses en détente de piston 3 de l'amortisseur 1 supérieures à 50 mm à partir de l'assiette de référence AR, jusqu'au maximum de 1 10 mm, correspondent à des débattements de forte énergie DHE qui représentent des sollicitations peu fréquentes. Ces sollicitations se rencontrent notamment quand les roues franchissent un obstacle important de type ralentisseur en dos-d'âne, ou un nid de poule relativement profond. [0031 ] Pour plus de commodités dans la suite de la description, nous parlerons des courses en attaque ou en détente du piston 3 de l'amortisseur 1 en valeur absolue. Finally, it is considered that races in piston attack 3 of the damper 1 beyond -50 mm from the reference base AR, up to the maximum of -80 mm, and races in piston expansion 3 of the damper 1 greater than 50 mm from the reference base AR, up to a maximum of 1 10 mm, correspond to high energy DHE deflections which represent infrequent solicitations. These stresses are encountered especially when the wheels cross a major hurdle-type retarder in the back of a donkey, or a relatively deep pothole. For more convenience in the following description, we will discuss the races in attack or relaxation of the piston 3 of the damper 1 in absolute value.
[0032] En se référant au graphe de la figure 1 B, la butée d'attaque mécanique 7 est comprimée dès que la course du piston 3 de l'amortisseur 1 dépasse une course en attaque d'environ 10 mm. Ainsi, la butée d'attaque mécanique 7 intervient rapidement pour freiner la course du piston 3 de l'amortisseur 1 dès le début des débattements de moyenne énergie DME. Au-delà d'une course en attaque du piston 3 de l'amortisseur 1 de 50 mm, c'est-à-dire pour des débattements de forte énergie DHE, le piston 3 de l'amortisseur hydraulique 1 provoque le déplacement du cylindre 10 de la butée d'attaque hydraulique 9 le long de son piston correspondant 1 1 , pour rapidement freiner le piston 3 de l'amortisseur 1 dans son cylindre 2 correspondant en ajoutant une force de freinage dépendant de la vitesse à la force de freinage de la butée mécanique 7. On protège ainsi la caisse 6 du véhicule contre des chocs en fin de course qui pourraient détruire des éléments. [0033] En se référant à nouveau au graphe de la figure 1 B, lorsque la course en détente du piston 3 de l'amortisseur 1 dépasse une valeur d'environ 70 mm le piston flottant 15 de la butée de détente hydraulique est déplacé et comprime simultanément le ressort constituant la butée de détente mécanique 16 lorsque la course en détente du piston 3 de l'amortisseur 1 dépasse une valeur d'environ 70 mm, pour rapidement freiner le piston 3 de l'amortisseur 1 dans son cylindre correspondant 2 par l'effet conjugué des deux butées de détente. Referring to the graph of Figure 1 B, the mechanical attack stop 7 is compressed as soon as the stroke of the piston 3 of the damper 1 exceeds an attack stroke of about 10 mm. Thus, 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. Beyond an attack stroke of the piston 3 of the damper 1 of 50 mm, that is to say for high energy deflections DHE, the piston 3 of the hydraulic damper 1 causes the displacement of the cylinder 10 of the hydraulic attack stop 9 along its corresponding piston 1 1, to quickly brake the piston 3 of the damper 1 in its cylinder 2 corresponding 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 end-of-stroke shocks that could destroy elements. Referring again to the graph of Figure 1 B, when the expansion stroke of the piston 3 of the damper 1 exceeds a value of about 70 mm the floating piston 15 of the hydraulic expansion stop is moved and simultaneously compresses the spring constituting the mechanical expansion stop 16 when the expansion stroke of the piston 3 of the damper 1 exceeds a value of about 70 mm, to quickly brake the piston 3 of the damper 1 in its corresponding cylinder 2 by the combined effect of the two trigger stops.
[0034] En se référant aux figures 2A et 2B, le système de suspension selon un premier mode de réalisation de l'invention va maintenant être décrit. Referring to Figures 2A and 2B, the suspension system according to a first embodiment of the invention will now be described.
[0035] Il comprend pour chaque roue du véhicule un amortisseur 1 b, un ressort de suspension 17 et deux butées de détente respectivement mécanique 16 et hydraulique 15 tels que décrits précédemment. It comprises for each wheel of the vehicle a shock absorber 1b, a suspension spring 17 and two respective mechanical 16 and hydraulic expansion stops 15 as described above.
[0036] Le système de suspension hydraulique selon l'invention comprend également pour chaque roue du véhicule une butée d'attaque mécanique 7b moins longue que la butée d'attaque mécanique 7 de l'art antérieur, ainsi qu'une butée d'attaque hydraulique 9b dont le cylindre 10b présente une amplitude de déplacement le long du piston correspondant 1 1 b entre sa fin de course en attaque et sa fin de course en détente comprise entre 40 et 60 mm. Cette amplitude de déplacement est plus grande que l'amplitude de déplacement du cylindre 10 de la butée d'attaque hydraulique 9 de l'art antérieur, qui est de l'ordre de 30 mm. The hydraulic suspension system according to the invention also comprises for each wheel of the vehicle a mechanical attack abutment 7b shorter than the mechanical attack abutment 7 of the prior art, as well as an attack 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 range of motion 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.
[0037] En outre, la structure du cylindre 10b de la butée d'attaque hydraulique 9b est différente, puisque le cylindre 10b comprend dans sa paroi une pluralité de trous radiaux traversants 13, et permettant l'entrée ou la sortie du fluide hydraulique de la chambre de compression 4 du cylindre 2 de l'amortisseur 1 b lorsque le piston 1 1 b et le cylindre 10b de la butée d'attaque hydraulique 9b se déplacent l'un par rapport à l'autre. Ainsi, à mesure que le cylindre 10b de la butée d'attaque hydraulique 9b se déplace le long du piston correspondant 1 1 b vers la paroi inférieure de fond 12 du cylindre 2 de l'amortisseur 1 b, un nombre croissant de trous traversants 13 sont bouchés par le piston 1 1 b de la butée d'attaque hydraulique 9b, diminuant ainsi la section globale des trous traversants 13 de sorte que l'effort de freinage exercé par la butée d'attaque hydraulique 9b sur la caisse 6 du véhicule augmente pour une vitesse de déplacement du cylindre 10b constante. In addition, 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. Thus, as the cylinder 10b of the hydraulic thrust bearing 9b moves along the corresponding piston 1 1b to the lower bottom wall 12 of the cylinder 2 of the shock absorber 1b, an increasing number of through holes 13 are blocked by the piston 1 1b of the hydraulic thrust bearing 9b, thus reducing the overall cross section of the through holes 13 so that the braking force exerted by the hydraulic thrust bearing 9b on the body 6 of the vehicle increases for a displacement speed of the cylinder 10b constant.
[0038] L'agencement des butées d'attaque mécanique 7b et hydraulique 9b en fonction des courses du piston 3 de l'amortisseur 1 b est également différent par rapport à celui de l'art antérieur. The arrangement of the mechanical attack abutments 7b and 9b hydraulic as a function of the strokes of the piston 3 of the damper 1b is also different compared to that of the prior art.
[0039] En effet, lorsque le piston 3 de l'amortisseur hydraulique 1 b dépasse une course en attaque CA1 comprise entre 0 et 20 mm, préférentiellement 10 mm, ce dernier entraine le déplacement du cylindre 10b de la butée d'attaque hydraulique 9b le long de son piston correspondant 1 1 b. Pour des débattements de faible et moyenne énergies, la section globale d'un grand nombre des trous 13 traversant le cylindre 10b de la butée d'attaque hydraulique 9b est suffisamment élevée pour assurer un freinage doux du piston 3 de l'amortisseur 1 . Pour des débattements de plus forte énergie DHE au cours desquels le piston 3 d'amortisseur 1 b se rapproche de sa fin de course en attaque, la section globale d'un moins grand nombre des trous 13 traversant le cylindre 10b de la butée d'attaque hydraulique 9b diminue car un nombre croissant de trous traversants 13 sont bouchés par le piston 1 1 b de la butée d'attaque hydraulique 9b à mesure que le cylindre 10b se déplace le long du piston 1 1 b de la butée d'attaque hydraulique 9b en direction de la paroi inférieure de fond 12 du cylindre 2 de l'amortisseur 1 b : cela assure un freinage de plus en plus fort du piston 3 de l'amortisseur 1 b dans le but de protéger la caisse 6 et le châssis du véhicule. Indeed, when the piston 3 of the hydraulic damper 1b exceeds an attacking stroke CA1 of between 0 and 20 mm, preferably 10 mm, the latter causes the displacement of the cylinder 10b of the hydraulic attack stop 9b along its corresponding piston 1 1 b. For low and medium energy deflections, the overall section of a large number of the holes 13 passing through the cylinder 10b of the hydraulic thrust bearing 9b is sufficiently high to ensure gentle braking of the piston 3 of the shock absorber 1. For DHE higher energy deflections during which the damper piston 3 b is approaching its end of attack stroke, 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.
[0040] En outre, dès que le piston 3 de l'amortisseur 1 b dépasse une course en attaque CA2 comprise entre 40 et 50 mm, préférentiellement 50 mm, la butée d'attaque mécanique 7b est comprimée et participe au renforcement du freinage du piston 3 de l'amortisseur 1 . In addition, as soon as the piston 3 of the damper 1b exceeds an attack stroke CA2 of between 40 and 50 mm, preferably 50 mm, the attack abutment 7b is compressed and participates in strengthening the braking of the piston 3 of the damper 1.
[0041 ] On notera que la discontinuité de l'effort exercé par le système de suspension lors de sa compression, génératrice d'inconfort pour les passagers du véhicule, est fortement diminuée grâce à la butée d'attaque hydraulique 9b, dont le cylindre 10b a une amplitude de déplacement allongée, qui agit avant la butée d'attaque mécanique 7b. En outre, l'effort exercé par la butée d'attaque hydraulique 9b dépendant à la fois de la vitesse et de l'amplitude de déplacement du piston 3 de l'amortisseur 1 b dans son cylindre 2, le freinage du piston 3 de l'amortisseur est adapté de manière progressive à l'amplitude et à la vitesse de sa course dans le cylindre 2, en particulier pour les débattements de moyenne énergie DME, ce qui a également un effet positif sur le confort des passagers. Enfin, la butée d'attaque hydraulique 9b dissipe l'énergie sans l'accumuler, évitant de fait tout effet de relance lors des débattements de faible et moyenne énergies. It will be noted that the discontinuity of the force exerted by the suspension system during its compression, which generates discomfort for the passengers of the vehicle, is greatly reduced thanks to the hydraulic attack stop 9b, whose cylinder 10b has an elongated displacement amplitude, which acts before the mechanical attack stop 7b. In addition, the force exerted by the hydraulic attack stop 9b depending both on the speed and the displacement amplitude of the piston 3 of the shock absorber 1b in its cylinder 2, the braking of the piston 3 of the The shock absorber is progressively adapted to the amplitude and the speed of its travel in the cylinder 2, in particular for the medium energy DME deflections, which also has a positive effect on passenger comfort. Finally, the hydraulic attack stop 9b dissipates the energy without accumulating it, thus avoiding any stimulus effect during low and medium energy deflections.
[0042] L'amortisseur 1 b comporte de plus des moyens de pilotage 30 qui modifient le niveau d'effort généré par le déplacement du piston 3 dans le cylindre 2, suivant des lois d'amortissement programmées, agissant par une liaison électrique reliée à un calculateur 32. Le niveau d'effort variable du déplacement du piston 3 dans le cylindre 2 est indiqué sur la figure 2B par une largeur variable de la zone rectangulaire représentant l'effort de l'amortisseur 1 b. [0043] En fonction d'un certain nombre d'informations reçues sur le fonctionnement du véhicule, comme sa vitesse ou le braquage des roues avant indiquant un virage, le calculateur 32 envoie un signal aux moyens de pilotage 30, notamment un courant d'intensité variable, pour modifier les passages du fluide de chaque côté du piston 3 de l'amortisseur 1 b afin de faire varier en temps réel le niveau d'effort et donc l'amortissement des oscillations de la suspension. On peut aussi prévoir une commande manœuvrée par le conducteur pour choisir différents modes, comme un mode confort et un mode sport. The damper 1b further comprises piloting means 30 which modify the level of effort generated by the displacement of the piston 3 in the cylinder 2, according to programmed damping laws, acting by an electrical connection connected to a calculator 32. The variable level of effort of the displacement of the piston 3 in the cylinder 2 is indicated in FIG. 2B by a variable width of the rectangular zone representing the force of the damper 1b. According to a certain amount of information received on the operation of the vehicle, as its speed or steering of the front wheels indicating a turn, the computer 32 sends a signal to the control means 30, in particular a current of variable intensity, to change the fluid passages on each side of the piston 3 of the damper 1b in order to vary in real time the level of effort and thus the damping of the oscillations of the suspension. One can also provide a control maneuvered by the driver to choose different modes, such as a comfort mode and a sport mode.
[0044] Le calculateur 32 peut comporter un nombre limité de lois d'amortissement, en particulier seulement deux lois prédéfinies commandées par un courant ou une absence de courant, ce qui représente un système très simple, ou une plage continue de variation du niveau d'amortissement. The computer 32 may comprise a limited number of damping laws, in particular only two predefined laws controlled by a current or an absence of current, which represents a very simple system, or a continuous range of variation of the level of current. 'amortization.
[0045] En se référant aux figures 4A et 4B, le système de suspension selon un second mode de réalisation de l'invention va maintenant être décrit. [0046] Les éléments qui portent sur ces figures les mêmes références que sur les figures 2A et 2B sont identiques à ceux-ci et ne sont donc pas décrits à nouveau ici. Referring to Figures 4A and 4B, the suspension system according to a second embodiment of the invention will now be described. The elements which bear on these figures the same references as in Figures 2A and 2B are identical to these and are therefore not described again here.
[0047] Le système de suspension hydraulique selon le second mode de réalisation de l'invention comprend également pour chaque roue du véhicule une butée de détente mécanique 16b plus longue que la butée de détente mécanique 16 de l'art antérieur. Par conséquent, le piston flottant de la butée de détente hydraulique 15b selon le second mode de réalisation de l'invention présente une amplitude de déplacement autour de la tige 14 de l'amortisseur 1 , entre sa position de repos et sa position de fin de course en détente, comprise entre par exemple entre 40 et 80 mm. Cette amplitude de déplacement est plus grande que l'amplitude de déplacement du piston flottant de la butée de détente hydraulique 15 de l'art antérieur, qui est de l'ordre de 20 à 30 mm. En outre, l'allongement de l'amplitude de déplacement de la butée de détente hydraulique 15b permet de diminuer la raideur du ressort de la butée de détente mécanique 16b, de sorte qu'il contribue peu au freinage du piston 3 de l'amortisseur 1 en détente. [0048] De plus, le piston flottant 15b de la butée de détente hydraulique est formé par une bague annulaire fendue radialement sur toute son épaisseur et destiné à coulisser le long de la tige 14 de l'amortisseur 1 de manière à conserver un espace annulaire 23b entre la tige 14 et le bord interne du piston flottant 15b, tandis que la partie supérieure de la chambre de détente 5 du cylindre 2 de l'amortisseur 1 comprend une paroi 2b de forme sensiblement tronconique dont la section transversale diminue en direction supérieure vers la paroi 8 de l'amortisseur 1 . Ainsi, l'effort exercé par les butées de détente 15b, 16b sur la caisse du véhicule augmente de manière très progressive avec la course du piston flottant 15b : à mesure que le piston flottant 15b se déplace vers la paroi d'extrémité supérieure 8 du cylindre 2 de l'amortisseur 1 le long de la paroi tronconique 2b, la fente et l'espace annulaire 23b du piston flottant 15b se referme progressivement, diminuant de fait la section de passage du fluide hydraulique. Cela assure donc un amortissement variable en fonction de la course du piston flottant 15b, améliorant significativement la maîtrise des mouvements verticaux de la caisse du véhicule, et de fait le confort du véhicule. 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 a displacement amplitude around the rod 14 of the damper 1, between its rest position and its end position. relaxation stroke, 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. In addition, 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 in relaxation. In addition, the floating piston 15b of the hydraulic expansion stop is formed by an annular ring radially split over its entire thickness and designed to slide along the rod 14 of the damper 1 so as to maintain an annular space. 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 1 comprises a wall 2b of substantially frustoconical shape whose cross section decreases in the upper direction towards the wall 8 of the damper 1. Thus, 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 1 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.
[0049] En se référant à la figure 3, valable pour les deux modes de réalisation de l'invention, l'axe horizontal représente la vitesse de déplacement V du piston 3 dans le cylindre 2, exprimée en mètres par seconde, l'axe vertical représente l'effort exprimé en daN sur ce piston. On a différentes lois d'amortissement 34 pour des courants variables appliqués dans les moyens de pilotage 30, présentées pour un incrément du courant de 0,1 A, qui vont d'un amortissement très faible 36 compris entre -75 et +150 daN pour un courant de 0,4 A, à un amortissement élevé 38 compris entre -600 et + 650daN pour un courant de 1 ,6A. Referring to Figure 3, valid for both embodiments of the invention, the horizontal axis represents the displacement velocity V of the piston 3 in the cylinder 2, expressed in meters per second, the axis vertical represents the force expressed in daN on this piston. Different damping laws 34 are applied for variable currents applied in the control means 30, presented for an increment of the current of 0.1 A, which range from a very low damping 36 between -75 and +150 daN for a current of 0.4 A, with a high damping 38 between -600 and + 650daN for a current of 1, 6A .
[0050] Dans le cas d'une absence de courant dans les moyens de pilotage 30, par exemple suite à une défaillance du calculateur 32, ces moyens de pilotage sont prévus pour se mettre automatiquement dans un état donnant une loi d'amortissement moyenne 40 qui permet de continuer le trajet avec un compromis entre le confort et la sécurité qui est suffisant. In the case of a lack of current in the control means 30, for example following a failure of the computer 32, these control means are provided to automatically enter a state giving an average damping law 40 which allows to continue the journey with a compromise between comfort and safety which is sufficient.
[0051 ] On obtient un confort de suspension amélioré par la combinaison des éléments du système de suspension hydraulique de l'invention. En effet, on prévoit un niveau d'effort faible ou très faible de l'amortisseur 1 b pour les débattements à petite énergie DLE, qui n'atteignent pas la course en attaque CA1 agissant sur la butée d'attaque hydraulique 9b afin d'obtenir des mouvements de la caisse 6 plus lents et présentant une plus grande amplitude. On a donc une diminution des efforts de suspension pour les débattements de faible énergie, et une meilleure absorption des petites irrégularités de la route. Improved suspension comfort is obtained by combining the elements of the hydraulic suspension system of the invention. Indeed, a low or very low level of effort of the damper 1b is provided for the low-energy DLE deflections, which do not reach the attack stroke CA1 acting on the hydraulic attack stop 9b in order to obtain movements of the body 6 that are slower and have a greater amplitude. There is therefore a reduction in suspension forces for low energy deflections, and better absorption of small irregularities of the road.
[0052] On prévoit ensuite pour des irrégularités de la route plus importantes avec des débattements en attaque à moyenne énergie DME, une augmentation progressive du niveau des efforts de l'amortisseur 1 b qui viennent s'ajouter aux efforts délivrés par la butée d'attaque hydraulique 9b, ayant aussi une action progressive en fonction des débattements et en fonction de la vitesse. It is then expected for more important road irregularities with deflections in medium energy DME attack, a gradual increase in the level of efforts of the damper 1b which are added to the efforts delivered by the stop of hydraulic attack 9b, also having a progressive action according to the deflections and according to the speed.
[0053] On prévoit enfin pour des irrégularités de la route importantes avec des débattements en attaque à haute énergie DHE, un niveau important des efforts de l'amortisseur, qui s'ajoutent à la fois aux efforts délivrés par la butée d'attaque hydraulique 9b et par la butée d'attaque mécanique 7b. Finally, it is provided for significant road irregularities with DHE high energy drive deflections, a significant level of the forces of the damper, which are added to both the forces delivered by the hydraulic attack abutment. 9b and by the mechanical attack stop 7b.
[0054] On notera que le système de suspension hydraulique selon l'invention comporte des techniques existantes disposées suivant une combinaison nouvelle, il peut donc être facilement développé et fabriqué avec des coûts réduits, en utilisant des technologies de production existante. [0055] La configuration telle que décrite n'est pas limitée aux modes de réalisation décrits précédemment et représentés sur les figures 2A, 2B, 4A et 4B. Elle n'a été donnée qu'à titre d'exemple non limitatif. De multiples modifications peuvent être apportées sans pour autant sortir du cadre de l'invention. En particulier, l'invention n'est pas limitée à une seule configuration de butée d'attaque hydraulique 9b. On pourrait par exemple imaginer une butée d'attaque hydraulique 9b dont le cylindre 10b est solidaire des parois internes de la chambre de compression 4 de l'amortisseur 1 b et dont le piston 1 1 b est destiné à être déplacé dans son cylindre correspondant 10b par le piston 3 de l'amortisseur 1 . Bien entendu, tout type de butée d'attaque hydraulique 9b connue et apte à être logée dans la chambre de compression 4 d'un amortisseur 1 b pourra être envisagé. On pourrait également imaginer pour chaque roue du véhicule un ressort de suspension 17 ou une butée d'attaque mécanique 7b déporté à l'extérieur de l'amortisseur hydraulique 1 b, monté en parallèle avec l'amortisseur hydraulique 1 b entre le porte-fusée de roue et la caisse 6 du véhicule. Note that the hydraulic suspension system according to the invention comprises existing techniques arranged in a new combination, it can be easily developed and manufactured with reduced costs, using existing production technologies. The configuration as described is not limited to the embodiments described above and shown in Figures 2A, 2B, 4A and 4B. It was not given as a non-limiting example. Multiple modifications can be made without departing from the scope of the invention. In particular, the invention is not limited to a single hydraulic thrust bearing configuration 9b. One could for example imagine 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 1. Of course, 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. One could also imagine for each wheel of the vehicle a suspension spring 17 or a mechanical attack abutment 7b offset outside the hydraulic damper 1b, mounted in parallel with the hydraulic damper 1b between the stub axle wheel and the body 6 of the vehicle.

Claims

REVENDICATIONS
1 . Système de suspension hydraulique d'un train roulant de véhicule, notamment automobile, comprenant pour chaque roue de ce train un amortisseur (1 b) à cylindre (2) et piston (3) mobile dans le cylindre pour y délimiter deux chambres (4, 5) respectivement de compression et de détente et interposé entre la caisse (6) du véhicule et le porte-fusée de roue du véhicule, une butée d'attaque hydraulique (9b) à piston montée dans la chambre de compression (4) et comportant un cylindre (10b) et un piston (1 1 b) mobiles l'un par rapport à l'autre, caractérisé en ce que le système de compression comprend de plus une butée d'attaque mécanique compressible (7b) positionnée entre le cylindre (2) et la caisse (6) du véhicule, ou entre le porte-fusée et la caisse (6) du véhicule, le piston (1 1 b) et le cylindre (10b) de la butée hydraulique (9b) étant destinés à être déplacés l'un par rapport à l'autre lors d'une course du piston (3) de l'amortisseur (1 b) lorsque ce dernier atteint une première course en attaque (CA1 ) dans le cylindre (2) de l'amortisseur (1 b), la butée d'attaque mécanique (7b) étant destinée à être comprimée entre le cylindre (2) de l'amortisseur et la caisse (6) du véhicule, ou entre le porte-fusée et la caisse (6) du véhicule, lorsque le piston (3) de l'amortisseur atteint une seconde course en attaque (CA2) dans le cylindre de l'amortisseur supérieure à la première course (CA1 ), et en ce que le système de suspension comprend un calculateur (32) agissant sur des moyens de pilotage (30) de l'amortisseur (1 b) qui modifient le niveau d'effort généré par le déplacement du piston (3) dans le cylindre (2). 1. Hydraulic suspension system for a vehicle undercarriage, in particular an automobile, comprising for each wheel of this train a damper (1b) with a cylinder (2) and a piston (3) movable in the cylinder in order to delimit two chambers (4, 5) respectively of compression and expansion and interposed between the body (6) of the vehicle and the wheel-carrier of the vehicle, a piston hydraulic thrust bearing (9b) mounted in the compression chamber (4) and comprising a cylinder (10b) and a piston (11b) movable relative to each other, characterized in that the compression system further comprises a compressible mechanical attack stop (7b) positioned between the cylinder ( 2) and the body (6) of the vehicle, or between the stub axle and the body (6) of the vehicle, the piston (1 1b) and the cylinder (10b) of the hydraulic abutment (9b) being intended to be displaced relative to each other during a stroke of the piston (3) of the damper (1b) when rnier reaches a first stroke (CA1) in the cylinder (2) of the damper (1b), the mechanical stop (7b) being intended to be compressed between the cylinder (2) of the damper and the body (6) of the vehicle, or between the stub axle and the body (6) of the vehicle, when the piston (3) of the damper reaches a second stroke (CA2) in the cylinder of the upper damper at the first stroke (CA1), and in that the suspension system comprises a computer (32) acting on control means (30) of the damper (1b) which modify the level of effort generated by the displacement piston (3) in the cylinder (2).
2. Système de suspension selon la revendication 1 , caractérisé en ce que la première course en attaque (CA1 ) du piston (3) de l'amortisseur (1 b) est comprise entre zéro et vingt millimètres à partir d'une assiette de référence (AR) du véhicule. 2. suspension system according to claim 1, characterized in that the first stroke (CA1) of the piston (3) of the damper (1 b) is between zero and twenty millimeters from a reference plate (AR) of the vehicle.
3. Système de suspension selon la revendication 1 ou 2, caractérisé en ce que la seconde course en attaque (CA2) du piston (3) de l'amortisseur (1 b) est supérieure à quarante millimètres à partir de l'assiette de référence (AR) du véhicule. 3. suspension system according to claim 1 or 2, characterized in that the second stroke (CA2) of the piston (3) of the damper (1 b) is greater than forty millimeters from the reference base (AR) of the vehicle.
4. Système de suspension selon la revendication 1 , caractérisé en ce que le calculateur (32) comporte un nombre de lois prédéfinissant le niveau d'effort généré par le déplacement du piston (3) dans le cylindre (2), qui est limité. 4. Suspension system according to claim 1, characterized in that the computer (32) comprises a number of laws predefining the level of effort generated by the displacement of the piston (3) in the cylinder (2), which is limited.
5. Système de suspension selon l'une quelconque des revendications 1 et 4, caractérisé en ce que le calculateur (32) comporte une plage de variation continue du niveau d'effort généré par le déplacement du piston (3) dans le cylindre (2). 5. Suspension system according to any one of claims 1 and 4, characterized in that the computer (32) comprises a continuous variation range of the level of effort generated by the displacement of the piston (3) in the cylinder (2). ).
6. Système de suspension selon la revendication 4 ou 5, caractérisé en ce que les moyens de pilotage (30) de l'amortisseur (1 b) comportent une fonction qui en l'absence de signal du calculateur (32), met automatiquement ces moyens dans un état donnant une loi d'amortissement intermédiaire (40) entre le niveau d'effort le plus faible (36) et celui le plus élevé (38). 6. suspension system according to claim 4 or 5, characterized in that the control means (30) of the damper (1 b) comprise a function which in the absence of signal from the computer (32), automatically sets these means in a state giving an intermediate damping law (40) between the lowest level of effort (36) and the highest level of effort (38).
7. Système de suspension selon l'une quelconque des revendications 1 à 6, caractérisé en ce que la butée d'attaque mécanique (7b) est en matériau élastomère et en ce qu'elle présente une section transversale annulaire de manière à être traversée par la tige (14) du piston de l'amortisseur (1 b) reliée à la caisse (6) du véhicule. 7. Suspension system according to any one of claims 1 to 6, characterized in that the mechanical attack stop (7b) is elastomeric material and in that it has an annular cross section so as to be traversed by the rod (14) of the piston of the damper (1b) connected to the body (6) of the vehicle.
8. Système de suspension selon l'une quelconque des revendications 1 et 4 à 6, caractérisé en ce qu'il comprend pour chaque roue du train roulant un ressort de suspension (17) monté autour de l'amortisseur (1 b). 8. A suspension system according to any one of claims 1 and 4 to 6, characterized in that it comprises for each wheel of the running gear a suspension spring (17) mounted around the damper (1b).
9. Système de suspension selon l'une quelconque des revendications 1 , 4 à 6 et 8, caractérisé en ce qu'il comprend en outre une butée de détente hydraulique (15b) montée dans la chambre de détente (5) du cylindre (2) de l'amortisseur correspondant (1 b). 9. Suspension system according to any one of claims 1, 4 to 6 and 8, characterized in that it further comprises a hydraulic expansion stop (15b) mounted in the expansion chamber (5) of the cylinder (2). ) of the corresponding damper (1b).
10. Système de suspension selon la revendication 9, caractérisé en ce que la butée de détente hydraulique (15b) est disposée pour agir lorsque la course en détente du piston (3) de l'amortisseur (1 b) atteint une course de détente (CD) inférieure à cinquante millimètres à partir de l'assiette de référence (AR) du véhicule. 10. Suspension system according to claim 9, characterized in that the hydraulic expansion stop (15b) is arranged to act when the expansion stroke of the piston (3) of the damper (1b) reaches an expansion stroke ( CD) less than fifty millimeters from the reference attitude (AR) of the vehicle.
1 1 . Système de suspension selon la revendication 9 ou 10, caractérisé en ce qu'il comporte une butée de détente mécanique (16b) qui est disposée pour agir en même temps que la butée de détente hydraulique (15b). 1 1. Suspension system according to claim 9 or 10, characterized in that it comprises a mechanical expansion stop (16b) which is arranged to act at the same time as the hydraulic expansion stop (15b).
12. Système de suspension selon la revendication 1 1 , caractérisé en ce que la butée de détente hydraulique (15b) comporte un piston flottant disposé dans la chambre de détente (5), entourant une tige (14) de l'amortisseur (1 b), comprenant un passage du fluide (23) entre les deux côtés de ce piston flottant, cette butée de détente hydraulique (15b) comportant de plus une collerette (22) solidaire de la tige (14), disposée d'un premier côté du piston flottant tourné vers le piston (3) de l'amortisseur (1 b), formant un clapet fermant le passage du fluide (23) quand elle est en appui sur ce piston flottant, et un ressort (16b) disposé de l'autre côté du piston flottant. 12. Suspension system according to claim 1 1, characterized in that the hydraulic expansion stop (15b) comprises a floating piston disposed in the expansion chamber (5), surrounding a rod (14) of the damper (1b). ), comprising a passage of the fluid (23) between the two sides of this floating piston, this hydraulic expansion stop (15b) further comprising a flange (22) integral with the rod (14), arranged on a first side of the floating piston turned towards the piston (3) of the damper (1b), forming a valve closing the passage of the fluid (23) when it bears on this floating piston, and a spring (16b) arranged on the other side of the floating piston.
13. Véhicule, notamment automobile, comprenant un système de suspension hydraulique selon l'une quelconque des revendications 1 à 12. 13. Vehicle, especially automobile, comprising a hydraulic suspension system according to any one of claims 1 to 12.
PCT/FR2017/050476 2016-03-25 2017-03-03 Hydraulic suspension system for a vehicle WO2017162948A1 (en)

Priority Applications (2)

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EP17713725.4A EP3433114A1 (en) 2016-03-25 2017-03-03 Hydraulic suspension system for a vehicle
CN201780019607.6A CN109070677B (en) 2016-03-25 2017-03-03 Hydraulic suspension system for vehicle

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
FR1652615A FR3049233B1 (en) 2016-03-25 2016-03-25 HYDRAULIC SUSPENSION SYSTEM OF A VEHICLE
FR1652614 2016-03-25
FR1652615 2016-03-25
FR1652614A FR3049229B1 (en) 2016-03-25 2016-03-25 HYDRAULIC SUSPENSION SYSTEM OF A VEHICLE

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US3211444A (en) * 1961-12-16 1965-10-12 Girling Ltd Hydraulic damper
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EP2977643A1 (en) * 2013-03-22 2016-01-27 KYB Corporation Shock absorber

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EP3433114A1 (en) 2019-01-30

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